64 results on '"Vallabhaneni, SR"'
Search Results
2. All-Causes and Aneurysm-Related Mortality During Late Follow-up After Endovascular AAA Repair
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Vallabhaneni, SR, Harris, PL, Gilling-Smith, GL, and van Marrewijk, C
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- 2001
3. Long-term follow-up of fenestrated endovascular repair for juxtarenal aortic aneurysm
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Roy, IN, Millen, AM, Jones, SM, Vallabhaneni, SR, Scurr, JRH, McWilliams, RG, Brennan, JA, and Fisher, RK
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surgical procedures, operative ,cardiovascular diseases - Abstract
BACKGROUND: Fenestrated endovascular aneurysm repair (FEVAR) is increasingly being used for juxtarenal aortic aneurysms. The aim of this study was to review long-term results and assess the importance of changing stent-graft design on outcomes. METHODS: This was a retrospective review of all patients who underwent FEVAR within a single unit over 12 years (February 2003 to December 2015). Kaplan-Meier analysis of survival, and freedom from target vessel loss, aneurysm expansion, graft-related endoleak and secondary intervention was performed. Comparison between outcomes of less complex grafts (fewer than 3 fenestrations) and more complex grafts (3 or 4 fenestrations) was undertaken. RESULTS: Some 173 patients underwent FEVAR; median age was 76 (i.q.r. 70-79) years and 90·2 per cent were men. Median aneurysm diameter was 63 (59-71) mm and median follow-up was 34 (16-50) months. The adjusted primary technical operative success rate was 95·4 per cent. The in-hospital mortality rate was 5·2 per cent; there was no known aneurysm-related death during follow-up. Median survival was 7·1 (95 per cent c.i. 5·2 to 8·1) years and overall survival was 60·1 per cent (104 of 173). There was a trend towards an increasing number of fenestrations in the graft design over time. In-hospital mortality appeared higher when more complex stent-grafts were used (8 versus 2 per cent for stent-grafts with 3-4 versus fewer than 3 fenestrations; P = 0·059). Graft-related endoleaks were more common following deployment of stent-grafts with three or four fenestrations (12 of 90 versus 6 of 83; P
- Published
- 2017
4. The use of fenestrated and branched endovascular aneurysm repair for juxtarenal and thoracoabdominal aneurysms: a systematic review and cost-effectiveness analysis
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Armstrong, Nigel, primary, Burgers, Laura, additional, Deshpande, Sohan, additional, Al, Maiwenn, additional, Riemsma, Rob, additional, Vallabhaneni, SR, additional, Holt, Peter, additional, Severens, Johan, additional, and Kleijnen, Jos, additional
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- 2014
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5. How I Do it: Fenestrated Endovascular Aneurysm Repair?
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Vallabhaneni, SR, primary
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- 2014
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6. Patch variability following carotid endarterectomy: a survey of Great Britain and Ireland
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Harrison, GJ, primary, Brennan, JA, additional, Naik, JB, additional, Vallabhaneni, SR, additional, and Fisher, RK, additional
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- 2012
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7. Adjunctive iliac stents reduce the risk of stent-graft limb occlusion following endovascular aneurysm repair with the Zenith stent-graft.
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Oshin OA, Fisher RK, Williams LA, Brennan JA, Gilling-Smith GL, Vallabhaneni SR, McWilliams RG, Oshin, Olufemi A, Fisher, Robert K, Williams, Leith A, Brennan, John A, Gilling-Smith, Geoffrey L, Vallabhaneni, S Rao, and McWilliams, Richard G
- Abstract
Purpose: To determine whether the introduction of a policy of adjunctive stent insertion based on preoperative CT assessment or completion angiography reduced the incidence of limb occlusion after stent-graft implantation for endovascular aneurysm repair (EVAR).Methods: A tertiary referral unit's endovascular database was retrospectively interrogated to compare the incidence of endograft limb occlusion in Zenith grafts following the introduction of a policy of selective adjunctive stent insertion. Group A included 288 limbs at risk in 146 patients (134 men; mean age 74+/-8 years) treated prior to August 2005 in whom adjunctive stents were inserted on an ad hoc basis only. Group B included 293 limbs at risk in 149 patients (127 men; mean age 76+/-7 years) treated after this date in whom a more aggressive adjunctive stenting strategy was adopted. Kaplan-Meier analysis was employed to compare outcomes.Results: In total, 295 patients underwent EVAR involving 581 iliac vessels, of which 11 (1.8%) occluded at a median of 24 months (0-27). Of 65 limbs extended into the external iliac segment, 5 (7.6%) subsequently occluded; in the remaining 516 limbs, there were 6 (1.1%) occlusions (p = 0.004). Across the study group, 38 (6.5%) adjunctive stents were deployed in limbs deemed at risk; 1 (2.6%) of these occluded. In the remaining 543 unstented limbs, 10 (1.8%) occlusions occurred (p = 0.15). There were 11 occlusions in group A, in which 5 (1.7%) adjunctive stents had been deployed, but none in group B, which had received 33 (11.2%) stents (p<0.0001). Kaplan-Meier survival curves identified primary patency rates at 36 months of 96% and 100%, respectively (p = 0.001).Conclusion: Adjunctive stenting significantly reduces the risk of postoperative stent-graft limb occlusion without obvious compromise to the aneurysm repair. [ABSTRACT FROM AUTHOR]- Published
- 2010
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8. Risk-adjusted outcome analysis of endovascular abdominal aortic aneurysm repair in a large population: how do stent-grafts compare?
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van Marrewijk CJ, Leurs LJ, Vallabhaneni SR, Harris PL, Buth J, Laheij RJF, EUROSTAR Collaborators, van Marrewijk, Corine J, Leurs, Lina J, Vallabhaneni, Srinivasa R, Harris, Peter L, Buth, Jacob, and Laheij, Robert J F
- Abstract
Purpose: To compare differences in the applicability and incidence of postoperative adverse events among stent-grafts used for repair of infrarenal aortic aneurysms.Methods: An analysis of 6787 patients from the EUROSTAR Registry database was conducted to compare aneurysm morphological features, patient characteristics, and postoperative events for the AneuRx, EVT/Ancure, Excluder, Stentor, Talent, and Zenith devices versus the Vanguard device (control) and each other. Annual incidence rates of complications were determined, and risks were compared using the Cox proportional hazards analysis.Results: The annual incidence rates were: device-related endoleak (types I and III) 6% (range 4%-10%), type II endoleak 5% (range 0.3%-11%), migration 3% (range 0.5%-5%), kinking 2% (range 1%-5%), occlusion 3% (range 1%-5%), rupture 0.5% (range 0%-1%), and all-cause mortality 7% (range 5%-8%). After adjustment for factors influencing outcome, AneuRx, Excluder, Talent, and Zenith devices were associated with a lower risk of migration, kinking, occlusion, and secondary intervention compared to the Vanguard device. Significant increased risk for conversion (EVT/Ancure) and reduced risk of aneurysm rupture (AneuRx and Zenith) and all-cause mortality (Excluder) were found compared to the Vanguard device.Conclusions: Significant differences exist between stent-grafts of different labels in terms of applicability and complications during intermediate to long-term follow-up. Since each stent-graft has its drawbacks, no single label can be identified as the best. It is reassuring that developments in stent-grafts indeed result in better performance than the early stent-grafts. However, a single device incorporating all the perceived improvements should still be pursued. [ABSTRACT FROM AUTHOR]- Published
- 2005
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9. EVAR in iliac occlusion.
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Scurr J, How T, Vallabhaneni SR, Torella F, McWilliams RG, Scurr, James, How, Thien, Vallabhaneni, S Rao, Torella, Francesco, and McWilliams, Richard G
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Purpose: To report the recanalization of an occluded common iliac artery (CIA) to allow endovascular repair of an abdominal aortic aneurysm (AAA) with a bifurcated stent-graft.Case Report: A 76-year-old man with a 75-mm infrarenal AAA and an occluded right CIA was successfully treated with a Zenith bifurcated stent-graft. The right CIA was recanalized allowing access, delivery, and deployment of the stent-graft. Follow-up computed tomography at 9 months showed no evidence of endoleak; maximum aneurysm diameter was reduced to 72 mm, and the iliac vessels were patent.Conclusion: Bifurcated stent-graft repair of an AAA can be performed following recanalization of an occluded CIA. This option may be preferable to an open repair or an aortomonoiliac stent-graft with extra-anatomical bypass in some patients. Long-term surveillance will be necessary to ensure freedom from iliac-related secondary intervention. [ABSTRACT FROM AUTHOR]- Published
- 2007
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10. Editor's Choice - Comparison of Open Surgery and Endovascular Techniques for Juxtarenal and Complex Neck Aortic Aneurysms: The UK COMPlex AneurySm Study (UK-COMPASS) - Peri-operative and Midterm Outcomes.
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Vallabhaneni SR, Patel SR, Campbell B, Boyle JR, Cook A, Crosher A, Holder SM, Jenkins MP, Ormesher DC, Rosala-Hallas A, and Jackson RJ
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Objective: Treatment of juxtarenal and complex neck abdominal aortic aneurysms (AAAs) is now commonly by endovascular rather than open surgical repair (OSR). Published comparisons show poor validity and scientific precision. UK-COMPASS is a comparative cohort study of endovascular treatments vs. OSR for patients with an AAA unsuitable for standard on label endovascular aneurysm repair (EVAR)., Methods: All procedures for AAA in England (November 2017 to October 2019) were identified, AAA anatomy assessed in a Corelab, peri-operative risk scores determined, and propensity scoring used to identify patients suitable for either endovascular treatment or OSR. Patients were stratified by aneurysm neck length (0 - 4 mm, 5 - 9 mm, or ≥ 10 mm) and operative risk; the highest quartile was considered high risk and the remainder standard risk. Death was the primary outcome measure. Endovascular treatments included fenestrated EVAR (FEVAR) and off label standard EVAR (± adjuncts)., Results: Among 8 994 patients, 2 757 had AAAs that were juxtarenal, short neck, or complex neck in morphology. Propensity score stratification and adjustment method comparisons included 1 916 patients. Widespread off label use of standard EVAR devices was noted (35.6% of patients). The adjusted peri-operative mortality rate was 2.9%, lower for EVAR (1.2%; p = .001) and FEVAR (2.2%; p = .001) than OSR (4.5%). In standard risk patients with a 0 - 4 mm neck, the mortality rate was 7.4% following OSR and 2.3% following FEVAR. Differences were smaller for patients with a neck length ≥ 5 mm: 2.1% OSR vs. 1.0% FEVAR. At 3.5 years of follow up, the overall mortality rate was 20.7% in the whole study population, higher following FEVAR (27.6%) and EVAR (25.2%) than after OSR (14.2%). However, in the 0 - 4 mm neck subgroup, overall survival remained equivalent. The aneurysm related mortality rate was equivalent between treatments, but re-intervention was more common after EVAR and FEVAR than OSR., Conclusion: FEVAR proves notably safer than OSR in the peri-operative period for juxtarenal aneurysms (0 - 4 mm neck length), with comparable midterm survival. For patients with short neck (5 - 9 mm) and complex neck (≥ 10 mm) AAAs, overall survival was worse in endovascularly treated patients compared with OSR despite relative peri-operative safety. This warrants further research and a re-appraisal of the current clinical application of endovascular strategies, particularly in patients with poor general survival outlook owing to comorbidity and age., (Copyright © 2024 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)
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- 2024
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11. Response to 'Re. Comparison of open, standard, and complex endovascular aortic repair treatments for juxtarenal/short neck aneurysms: a systematic review and network meta-analysis'.
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Patel SR, Lip GYH, and Vallabhaneni SR
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- Humans, Endovascular Aneurysm Repair, Network Meta-Analysis, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation, Aneurysm
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- 2023
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12. Aneurysm growth, survival, and quality of life in untreated thoracic aortic aneurysms: the effective treatments for thoracic aortic aneurysms study.
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Sharples L, Sastry P, Freeman C, Bicknell C, Chiu YD, Vallabhaneni SR, Cook A, Gray J, McCarthy A, McMeekin P, Vale L, and Large S
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- Adolescent, Adult, Aorta, Thoracic surgery, Follow-Up Studies, Humans, Prospective Studies, Quality of Life, State Medicine, Aortic Aneurysm, Thoracic surgery
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Aims: To observe, describe, and evaluate management and timing of intervention for patients with untreated thoracic aortic aneurysms., Methods and Results: Prospective study of UK National Health Service (NHS) patients aged ≥18 years, with new/existing arch or descending thoracic aortic aneurysms of ≥4 cm diameter, followed up until death, intervention, withdrawal, or July 2019. Outcomes were aneurysm growth, survival, quality of life (using the EQ-5D-5L utility index), and hospital admissions. Between 2014 and 2018, 886 patients were recruited from 30 NHS vascular/cardiothoracic units. Maximum aneurysm diameter was in the descending aorta in 725 (82%) patients, growing at 0.2 cm (0.17-0.24) per year. Aneurysms of ≥4 cm in the arch increased by 0.07 cm (0.02-0.12) per year. Baseline diameter was related to age and comorbidities, and no clinical correlates of growth were found. During follow-up, 129 patients died, 64 from aneurysm-related events. Adjusting for age, sex, and New York Heart Association dyspnoea index, risk of death increased with aneurysm size at baseline [hazard ratio (HR): 1.88 (95% confidence interval: 1.64-2.16) per cm, P < 0.001] and with growth [HR: 2.02 (1.70-2.41) per cm, P < 0.001]. Hospital admissions increased with aneurysm size [relative risk: 1.21 (1.05-1.38) per cm, P = 0.008]. Quality of life decreased annually for each 10-year increase in age [-0.013 (-0.019 to -0.007), P < 0.001] and for current smoking [-0.043 (-0.064 to -0.023), P = 0.004]. Aneurysm size was not associated with change in quality of life., Conclusion: International guidelines should consider increasing monitoring intervals to 12 months for small aneurysms and increasing intervention thresholds. Individualized decisions about surveillance/intervention should consider age, sex, size, growth, patient characteristics, and surgical risk., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2022
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13. Editor's Choice - Comparison of Open, Standard, and Complex Endovascular Aortic Repair Treatments for Juxtarenal/Short Neck Aneurysms: A Systematic Review and Network Meta-Analysis.
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Patel SR, Ormesher DC, Griffin R, Jackson RJ, Lip GYH, and Vallabhaneni SR
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Objective: Abdominal aortic aneurysms (AAAs) with adverse morphology of the aneurysm neck are "complex". Techniques employed to repair complex aneurysms include open surgical repair (OSR) and a number of on label endovascular techniques such as fenestrated endovascular aneurysm repair (FEVAR) and endovascular aneurysm repair (EVAR) with adjuncts (including chimneys and endo-anchors), as well as off label use of standard EVAR. The aim was to conduct a network meta-analysis (NMA) of published comparative outcomes., Data Sources: An electronic search was performed in Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL). These databases were interrogated using the PubMed interface and the Healthcare Databases Advanced Search (HDAS) interface developed by the National Institute of Health and Care Excellence., Review Methods: Online databases were interrogated up to April 2020. Studies were included if they compared outcomes between at least two methods of repair for complex aneurysms (those with at least one adverse neck feature: absent/short neck, conicality, angulation, calcification, large diameter, and thrombus). The primary outcome measure was peri-operative death. Pre-registration was done in PROSPERO (CRD42020177482)., Results: The search identified 24 observational studies and 7854 patients who underwent OSR, FEVAR, off label EVAR, or chimney EVAR. No comparative studies included EVAR with endo-anchors. NMA was performed on 23 studies that reported outcomes of aneurysms with short/absent infrarenal neck. Compared with OSR, off label EVAR (relative risk [RR] 0.10, 95% confidence interval [CI] 0.01 - 0.41) and FEVAR (RR 0.62, 95% CI 0.32-0.94) were associated with lower peri-operative mortality. This difference was not seen at the midterm follow up (30 months). Compared with OSR, FEVAR was associated with a lower peri-operative myocardial infarction (MI) rate (RR 0.37, 95% CI 0.16 - 0.62) but a higher midterm re-intervention rate (hazard ratio 1.65, 95% CI 1.04 - 2.66). All studies had a "moderate" or "high" risk of bias. Confidence in the network findings (GRADE) was generally "low"., Conclusion: This NMA demonstrated a peri-operative survival benefit for off label EVAR and FEVAR compared with OSR, potentially due to reduced risk of MI. FEVAR carries a greater midterm re-intervention risk than OSR, with potential implications for cost effectiveness. There is paucity of comparative data for cases with adverse neck features other than short length., (Copyright © 2022 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)
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- 2022
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14. Endovascular stent grafting and open surgical replacement for chronic thoracic aortic aneurysms: a systematic review and prospective cohort study.
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Sharples L, Sastry P, Freeman C, Gray J, McCarthy A, Chiu YD, Bicknell C, McMeekin P, Vallabhaneni SR, Cook A, Vale L, and Large S
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- Adolescent, Aged, Aged, 80 and over, Child, Cohort Studies, Cost-Benefit Analysis, Female, Humans, Middle Aged, Prospective Studies, Quality of Life, Stents, Aortic Aneurysm, Thoracic etiology, Aortic Aneurysm, Thoracic surgery, Endovascular Procedures methods
- Abstract
Background: The management of chronic thoracic aortic aneurysms includes conservative management, watchful waiting, endovascular stent grafting and open surgical replacement. The Effective Treatments for Thoracic Aortic Aneurysms (ETTAA) study investigates timing and intervention choice., Objective: To describe pre- and post-intervention management of and outcomes for chronic thoracic aortic aneurysms., Design: A systematic review of intervention effects; a Delphi study of 360 case scenarios based on aneurysm size, location, age, operative risk and connective tissue disorders; and a prospective cohort study of growth, clinical outcomes, costs and quality of life., Setting: Thirty NHS vascular/cardiothoracic units., Participants: Patients aged > 17 years who had existing or new aneurysms of ≥ 4 cm in diameter in the arch, descending or thoracoabdominal aorta., Interventions: Endovascular stent grafting and open surgical replacement., Main Outcomes: Pre-intervention aneurysm growth, pre-/post-intervention survival, clinical events, readmissions and quality of life; and descriptive statistics for costs and quality-adjusted life-years over 12 months and value of information using a propensity score-matched subsample., Results: The review identified five comparative cohort studies (endovascular stent grafting patients, n = 3955; open surgical replacement patients, n = 21,197). Pooled short-term all-cause mortality favoured endovascular stent grafting (odds ratio 0.71, 95% confidence interval 0.51 to 0.98; no heterogeneity). Data on survival beyond 30 days were mixed. Fewer short-term complications were reported with endovascular stent grafting. The Delphi study included 20 experts (13 centres). For patients with aneurysms of ≤ 6.0 cm in diameter, watchful waiting was preferred. For patients with aneurysms of > 6.0 cm, open surgical replacement was preferred in the arch, except for elderly or high-risk patients, and in the descending aorta if patients had connective tissue disorders. Otherwise endovascular stent grafting was preferred. Between 2014 and 2018, 886 patients were recruited (watchful waiting, n = 489; conservative management, n = 112; endovascular stent grafting, n = 150; open surgical replacement, n = 135). Pre-intervention death rate was 8.6% per patient-year; 49.6% of deaths were aneurysm related. Death rates were higher for women (hazard ratio 1.79, 95% confidence interval 1.25 to 2.57; p = 0.001) and older patients (age 61-70 years: hazard ratio 2.50, 95% confidence interval 0.76 to 5.43; age 71-80 years: hazard ratio 3.49, 95% confidence interval 1.26 to 9.66; age > 80 years: hazard ratio 7.01, 95% confidence interval 2.50 to 19.62; all compared with age < 60 years, p < 0.001) and per 1-cm increase in diameter (hazard ratio 1.90, 95% confidence interval 1.65 to 2.18; p = 0.001). The results were similar for aneurysm-related deaths. Decline per year in quality of life was greater for older patients (additional change -0.013 per decade increase in age, 95% confidence interval -0.019 to -0.007; p < 0.001) and smokers (additional change for ex-smokers compared with non-smokers 0.003, 95% confidence interval -0.026 to 0.032; additional change for current smokers compared with non-smokers -0.034, 95% confidence interval -0.057 to -0.01; p = 0.004). At the time of intervention, endovascular stent grafting patients were older (age difference 7.1 years; 95% confidence interval 4.7 to 9.5 years; p < 0.001) and more likely to be smokers (75.8% vs. 66.4%; p = 0.080), have valve disease (89.9% vs. 71.6%; p < 0.0001), have chronic obstructive pulmonary disease (21.3% vs. 13.3%; p = 0.087), be at New York Heart Association stage III/IV (22.3% vs. 16.0%; p = 0.217), have lower levels of haemoglobin (difference -6.8 g/l, 95% confidence interval -11.2 to -2.4 g/l; p = 0.003) and take statins (69.3% vs. 42.2%; p < 0.0001). Ten (6.7%) endovascular stent grafting and 15 (11.1%) open surgical replacement patients died within 30 days of the procedure ( p = 0.2107). One-year overall survival was 82.5% (95% confidence interval 75.2% to 87.8%) after endovascular stent grafting and 79.3% (95% confidence interval 71.1% to 85.4%) after open surgical replacement. Variables affecting survival were aneurysm site, age, New York Heart Association stage and time waiting for procedure. For endovascular stent grafting, utility decreased slightly, by -0.017 (95% confidence interval -0.062 to 0.027), in the first 6 weeks. For open surgical replacement, there was a substantial decrease of -0.160 (95% confidence interval -0.199 to -0.121; p < 0.001) up to 6 weeks after the procedure. Over 12 months endovascular stent grafting was less costly, with higher quality-adjusted life-years. Formal economic analysis was unfeasible., Limitations: The study was limited by small numbers of patients receiving interventions and because only 53% of patients were suitable for both interventions., Conclusions: Small (4-6 cm) aneurysms require close observation. Larger (> 6 cm) aneurysms require intervention without delay. Endovascular stent grafting and open surgical replacement were successful for carefully selected patients, but cost comparisons were unfeasible. The choice of intervention is well established, but the timing of intervention remains challenging., Future Work: Further research should include an analysis of the risk factors for growth/rupture and long-term outcomes., Trial Registration: Current Controlled Trials ISRCTN04044627 and NCT02010892., Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 6. See the NIHR Journals Library website for further project information.
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- 2022
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15. A risk-adjusted and anatomically stratified cohort comparison study of open surgery, endovascular techniques and medical management for juxtarenal aortic aneurysms-the UK COMPlex AneurySm Study (UK-COMPASS): a study protocol.
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Patel SR, Ormesher DC, Smith SR, Wong KHF, Bevis P, Bicknell CD, Boyle JR, Brennan JA, Campbell B, Cook A, Crosher AP, Duarte RV, Flett MM, Gamble C, Jackson RJ, Juszczak MT, Loftus IM, Nordon IM, Patel JV, Platt K, Psarelli EE, Rowlands PC, Smyth JV, Spachos T, Taggart L, Taylor C, and Vallabhaneni SR
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- Cohort Studies, Humans, Postoperative Complications, Quality of Life, Risk Factors, State Medicine, Treatment Outcome, United Kingdom, Aortic Aneurysm, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation, Endovascular Procedures
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Introduction: In one-third of all abdominal aortic aneurysms (AAAs), the aneurysm neck is short (juxtarenal) or shows other adverse anatomical features rendering operations more complex, hazardous and expensive. Surgical options include open surgical repair and endovascular aneurysm repair (EVAR) techniques including fenestrated EVAR, EVAR with adjuncts (chimneys/endoanchors) and off-label standard EVAR. The aim of the UK COMPlex AneurySm Study (UK-COMPASS) is to answer the research question identified by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme: 'What is the clinical and cost-effectiveness of strategies for the management of juxtarenal AAA, including fenestrated endovascular repair?', Methods and Analysis: UK-COMPASS is a cohort study comparing clinical and cost-effectiveness of different strategies used to manage complex AAAs with stratification of physiological fitness and anatomical complexity, with statistical correction for baseline risk and indication biases. There are two data streams. First, a stream of routinely collected data from Hospital Episode Statistics and National Vascular Registry (NVR). Preoperative CT scans of all patients who underwent elective AAA repair in England between 1 November 2017 and 31 October 2019 are subjected to Corelab analysis to accurately identify and include every complex aneurysm treated. Second, a site-reported data stream regarding quality of life and treatment costs from prospectively recruited patients across England. Site recruitment also includes patients with complex aneurysms larger than 55 mm diameter in whom an operation is deferred (medical management). The primary outcome measure is perioperative all-cause mortality. Follow-up will be to a median of 5 years., Ethics and Dissemination: The study has received full regulatory approvals from a Research Ethics Committee, the Confidentiality Advisory Group and the Health Research Authority. Data sharing agreements are in place with National Health Service Digital and the NVR. Dissemination will be via NIHR HTA reporting, peer-reviewed journals and conferences., Trial Registration Number: ISRCTN85731188., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)
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- 2021
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16. Review new concepts in pharmacotherapy for peripheral arterial disease.
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Kotalczyk A, Vallabhaneni SR, and Lip GYH
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- Aspirin therapeutic use, Drug Therapy, Combination, Humans, Platelet Aggregation Inhibitors therapeutic use, Rivaroxaban therapeutic use, Peripheral Arterial Disease drug therapy
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Purpose of Review: To provide an overview of new concepts in the pharmacotherapy of patients with peripheral artery disease (PAD)., Recent Findings: Modern therapeutic strategies for patients with PAD include specific symptom management and multidisciplinary prevention of cardiovascular events. Low-dose rivaroxaban in combination with aspirin improves outcomes compared with aspirin monotherapy among patients with PAD. Other novel concepts include the use of bosentan, vorapaxar or sildenafil among symptomatic patients with PAD. Likewise, lipid-lowering therapy reduces the risk of major cardiovascular and limb events., Summary: Personalized management, identification of risk factors and shared-decision making are crucial in improving the best medical therapy for patients with PAD. Further studies are needed to assess the long-term safety and efficacy of novel strategies in real-world patients., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2021
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17. Low-dose rivaroxaban plus aspirin for elderly patients with symptomatic peripheral artery disease: is it worth the bleeding risk?
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Zhang J, Vallabhaneni SR, and Lip GYH
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- Aged, Aspirin adverse effects, Factor Xa Inhibitors adverse effects, Humans, Peripheral Arterial Disease drug therapy, Rivaroxaban adverse effects
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- 2021
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18. Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR).
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Patel SR, Roy IN, McWilliams RG, Brennan JA, Vallabhaneni SR, Neequaye SK, Smout JD, and Fisher RK
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Background: In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre., Methods: A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels., Results: Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7-5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush., Conclusion: Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located., Competing Interests: Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)
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- 2021
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19. Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study.
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Dattani N, Shalhoub J, Nandhra S, Lane T, Abu-Own A, Elbasty A, Jones A, Duncan A, Garnham A, Thapar A, Murray A, Baig A, Saratzis A, Sharif A, Huasen B, Dawkins C, Nesbitt C, Carradice D, Morrow D, Bosanquet D, Kavanagh E, Shaikh F, Gosi G, Ambler G, Fulton G, Singh G, Travers H, Moore H, Olivier J, Hitchman L, O'Donohoe M, Popplewell M, Medani M, Jenkins M, Goh MA, Lyons O, McBride O, Moxey P, Stather P, Burns P, Forsythe R, Sam R, Brar R, Brightwell R, Benson R, Onida S, Paravastu S, Lambracos S, Vallabhaneni SR, Walsh S, Aktar T, Moloney T, Mzimba Z, and Nyamekye I
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- Anticoagulants, Heparin, Low-Molecular-Weight adverse effects, Humans, Ireland epidemiology, Risk Factors, United Kingdom, Venous Thromboembolism epidemiology, Venous Thromboembolism etiology, Venous Thromboembolism prevention & control
- Abstract
Objectives: Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus., Methods: A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). 'Good' and 'very good' consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively., Results: Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, 'good' and 'very good' consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, 'very good' consensus was achieved for 3/3 statements., Conclusions: The main findings from this study were that there was 'good' or 'very good' consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.
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- 2020
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20. Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation.
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Brazzelli M, Hernández R, Sharma P, Robertson C, Shimonovich M, MacLennan G, Fraser C, Jamieson R, and Vallabhaneni SR
- Subjects
- Humans, Quality-Adjusted Life Years, Technology Assessment, Biomedical, Treatment Outcome, Ultrasonography economics, Aortic Aneurysm, Abdominal surgery, Contrast Media, Cost-Benefit Analysis, Endovascular Procedures methods, Ultrasonography methods
- Abstract
Background: Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA., Objectives: To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance., Data Sources: Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016., Methods: We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis., Results: We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups., Limitations: Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data., Conclusions: Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases., Future Work: Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification., Study Registration: This study is registered as PROSPERO CRD42016036475., Funding: The National Institute for Health Research Health Technology Assessment programme., Competing Interests: No competing interests were declared.
- Published
- 2018
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21. Prospective, single UK centre, comparative study of the predictive values of contrast-enhanced ultrasound compared to time-resolved CT angiography in the detection and characterisation of endoleaks in high-risk patients undergoing endovascular aneurysm repair surveillance: a protocol.
- Author
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Roy IN, Chan TY, Czanner G, Wallace S, and Vallabhaneni SR
- Subjects
- Aortic Aneurysm, Abdominal, Contrast Media, Endovascular Procedures, Humans, Predictive Value of Tests, Prospective Studies, Tomography, X-Ray Computed, Aortography, Computed Tomography Angiography, Endoleak diagnostic imaging
- Abstract
Introduction: Diagnosis of endoleaks is imperative to prevent failure of endovascular aneurysm repairs (EVARs). The gold standard for diagnosis of endoleaks is catheter-directed subtraction angiography, which is not a practicable choice for surveillance. CT angiography (CTA) is the historical surveillance modality of choice. Concerns over cost, potential nephrotoxicity of contrast agents and repeated radiation exposure led to colour duplex ultrasound scan (CDUS) becoming an established alternative. CDUS has a lower sensitivity and specificity for endoleaks detection compared to CTA. Contrast-enhanced ultrasound scan (CEUS) represents an improvement of ultrasound imaging but comparisons against CTA report widely varying results, likely due to technical factors of CEUS and limitations of single-phase CTA.The development of time-resolved CTA (tCTA) offers timing information that much more closely mirrors the dynamic information available from CEUS. Theoretically, these two imaging modalities have the best potential for diagnostic accuracy. The aim of this study will be to compare CEUS to tCTA and investigate the utility of other measurements available from tCTA., Methods and Analysis: This is a prospective, single UK centre, comparative study of paired binary diagnostic imaging modalities. Patients identified in routine post-EVAR surveillance as at risk of having a graft-related endoleak will undergo a CEUS and tCTA on the same day. This will allow the first comparison of CEUS to a semidynamic form of CTA. CEUS sensitivity and specificity to endoleak detection will be calculated., Ethics and Dissemination: The study has achieved ethical approval. We hope the results will define the diagnostic accuracy of CEUS in comparison to a semidynamic form of CTA, representing a methodological improvement from previous studies. Results will be submitted for presentation at national and international vascular surgeryandradiology meetings. The full results are planned to be published in a medical journal., Trial Registration Number: NCT02688751., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)
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- 2018
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22. Lowering Size Threshold for Elective Repair to Reduce Deaths from Abdominal Aortic Aneurysms - A Simple Solution to a Complex Problem?
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Vallabhaneni SR and Campbell WB
- Subjects
- Elective Surgical Procedures, Humans, Aortic Aneurysm, Abdominal surgery, Aortic Rupture surgery
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- 2017
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23. Long-term follow-up of fenestrated endovascular repair for juxtarenal aortic aneurysm.
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Roy IN, Millen AM, Jones SM, Vallabhaneni SR, Scurr JRH, McWilliams RG, Brennan JA, and Fisher RK
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- Aftercare, Aged, Aortic Aneurysm, Abdominal mortality, Blood Vessel Prosthesis trends, Endovascular Procedures instrumentation, Endovascular Procedures mortality, Female, Humans, Intraoperative Complications etiology, Intraoperative Complications mortality, Length of Stay, Male, Operative Time, Postoperative Complications etiology, Postoperative Complications mortality, Prosthesis Design mortality, Prosthesis Design trends, Retrospective Studies, Surgical Wound Dehiscence etiology, Surgical Wound Dehiscence metabolism, Survival Analysis, Aortic Aneurysm, Abdominal surgery, Endovascular Procedures methods, Stents trends
- Abstract
Background: Fenestrated endovascular aneurysm repair (FEVAR) is increasingly being used for juxtarenal aortic aneurysms. The aim of this study was to review long-term results and assess the importance of changing stent-graft design on outcomes., Methods: This was a retrospective review of all patients who underwent FEVAR within a single unit over 12 years (February 2003 to December 2015). Kaplan-Meier analysis of survival, and freedom from target vessel loss, aneurysm expansion, graft-related endoleak and secondary intervention was performed. Comparison between outcomes of less complex grafts (fewer than 3 fenestrations) and more complex grafts (3 or 4 fenestrations) was undertaken., Results: Some 173 patients underwent FEVAR; median age was 76 (i.q.r. 70-79) years and 90·2 per cent were men. Median aneurysm diameter was 63 (59-71) mm and median follow-up was 34 (16-50) months. The adjusted primary technical operative success rate was 95·4 per cent. The in-hospital mortality rate was 5·2 per cent; there was no known aneurysm-related death during follow-up. Median survival was 7·1 (95 per cent c.i. 5·2 to 8·1) years and overall survival was 60·1 per cent (104 of 173). There was a trend towards an increasing number of fenestrations in the graft design over time. In-hospital mortality appeared higher when more complex stent-grafts were used (8 versus 2 per cent for stent-grafts with 3-4 versus fewer than 3 fenestrations; P = 0·059). Graft-related endoleaks were more common following deployment of stent-grafts with three or four fenestrations (12 of 90 versus 6 of 83; P < 0·001)., Conclusion: Fenestrated endovascular aneurysm repair for juxtarenal aneurysm is associated with few aneurysm-related deaths in the long term. Significant numbers of secondary interventions are required, but the majority of these can be performed using an endovascular approach., (© 2017 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS Society Ltd.)
- Published
- 2017
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24. Type IIIb Endoleak With the Endurant Stent-Graft.
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McWilliams RG, Vallabhaneni SR, Naik J, Torella F, and Fisher RK
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal diagnosis, Aortography methods, Blood Vessel Prosthesis Implantation adverse effects, Endoleak diagnosis, Endoleak surgery, Endovascular Procedures adverse effects, Humans, Male, Prosthesis Design, Reoperation, Tomography, X-Ray Computed, Treatment Outcome, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Endoleak etiology, Endovascular Procedures instrumentation, Stents
- Abstract
Purpose: To report 2 cases of type IIIb endoleak with the Endurant stent-graft and postulate the cause for the events., Case Report: A type IIIb endoleak was diagnosed at open conversion for a ruptured aneurysm 4 years after implantation of an Endurant stent-graft. In the other case, the endoleak was diagnosed at angiography 4 years after the Endurant stent-graft was implanted; the stent-graft was relined. In both cases the fabric hole was in the body of the stent-graft at the level of the top of the contralateral limb., Conclusion: The cause of the type IIIb endoleaks in these cases was fabric erosion likely due to interaction between the bare metal at the top of the contralateral limb and the fabric of the stent-graft body., (© The Author(s) 2015.)
- Published
- 2016
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25. Late Rupture of Abdominal Aortic Aneurysm After Previous Endovascular Repair: A Systematic Review and Meta-analysis.
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Antoniou GA, Georgiadis GS, Antoniou SA, Neequaye S, Brennan JA, Torella F, and Vallabhaneni SR
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- Aortic Aneurysm, Abdominal diagnosis, Aortic Aneurysm, Abdominal mortality, Aortic Rupture diagnosis, Aortic Rupture mortality, Aortic Rupture therapy, Blood Vessel Prosthesis Implantation mortality, Endoleak diagnosis, Endoleak mortality, Endoleak therapy, Endovascular Procedures mortality, Hospital Mortality, Humans, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Aortic Aneurysm, Abdominal surgery, Aortic Rupture etiology, Blood Vessel Prosthesis Implantation adverse effects, Endoleak etiology, Endovascular Procedures adverse effects
- Abstract
Purpose: To report a systematic literature review of late rupture of abdominal aortic aneurysm (AAA) after endovascular aneurysm repair (EVAR) and the results of a pooled analysis of causes, treatment, and outcomes., Methods: Electronic information sources and bibliographic reference lists were interrogated using a combination of free text and controlled vocabulary searches; 11 articles were ultimately identified that fulfilled the inclusion criteria. The articles reported a total of 190 patients who were included in the qualitative and quantitative synthesis. Mortality within 30 days or during the admission with aneurysm rupture was a primary endpoint; major perioperative morbidity was a secondary endpoint. A meta-analysis was performed for 30-day/in-hospital mortality using the random effects model., Results: A total of 152 ruptures occurred after 16,974 EVAR procedures reported by 8 of the case series, giving an incidence of 0.9% [95% confidence interval (CI) 0.77 to 1.05]. The mean time to rupture was 37 months. Twenty-nine percent (95% CI 20 to 39) of the patients had at least one previous secondary endovascular intervention following the initial EVAR, and 37% (95% CI 30 to 45) were not compliant with surveillance. Type I and III endoleaks were the predominant causes of rupture. Open surgical treatment was undertaken in 61% (95% CI 53 to 68) of the patients who underwent treatment. The pooled estimate for perioperative mortality was 32% (95% CI 24 to 41). A significantly lower mortality was found with endovascular treatment than open surgical management (p=0.027)., Conclusion: Graft-related endoleaks appear to be the predominant causes of late aneurysm rupture. Quality of and compliance with post-EVAR surveillance are important factors in late rupture; a large proportion of late ruptures are amenable to endovascular treatment., (© The Author(s) 2015.)
- Published
- 2015
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26. Pragmatic minimum reporting standards for thoracic endovascular aortic repair.
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Bosanquet DC, Twine CP, Tang TY, Boyle JR, Bell RE, Bicknell CD, Jenkins MP, Loftus IM, Modarai B, and Vallabhaneni SR
- Subjects
- Aortic Diseases diagnosis, Blood Vessel Prosthesis Implantation adverse effects, Endovascular Procedures adverse effects, Humans, Postoperative Complications etiology, Risk Factors, Treatment Outcome, Aorta, Thoracic surgery, Aortic Diseases surgery, Blood Vessel Prosthesis Implantation standards, Endovascular Procedures standards, Research Design standards
- Published
- 2015
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27. Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery.
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Antoniou GA, Hajibandeh S, Hajibandeh S, Vallabhaneni SR, Brennan JA, and Torella F
- Subjects
- Chi-Square Distribution, Humans, Kidney Diseases etiology, Kidney Diseases mortality, Kidney Diseases prevention & control, Myocardial Infarction etiology, Myocardial Infarction mortality, Myocardial Infarction prevention & control, Odds Ratio, Risk Assessment, Risk Factors, Stroke etiology, Stroke mortality, Stroke prevention & control, Treatment Outcome, Endovascular Procedures adverse effects, Endovascular Procedures mortality, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Vascular Surgical Procedures adverse effects, Vascular Surgical Procedures mortality
- Abstract
Background: Compelling evidence from large randomized trials demonstrates the salutary effects of statins on primary and secondary protection from adverse cardiovascular events in high-risk populations. Our objective was to investigate the role of perioperative statin therapy in noncardiac vascular and endovascular surgery., Methods: Electronic information sources were systematically searched to identify studies comparing outcomes after noncardiac surgical or endovascular arterial reconstruction in patients who were and were not taking statin in the perioperative or peri-interventional period. The Cochrane Collaboration's tool and the Newcastle-Ottawa scale were used to assess the methodologic quality and risk of bias of the selected studies. Random-effects models were applied to calculate pooled outcome data., Results: Four randomized controlled trials and 20 observational cohort or case-control studies were selected for analysis. The randomized studies enrolled 675 patients, and the observational studies enrolled 22,861 patients. Statin therapy was associated with a significantly lower risk of all-cause mortality (odds ratio [OR], 0.54; 95% CI, [CI], 0.38-0.78), myocardial infarction (OR, 0.62; 95% CI, 0.45-0.87), stroke (OR, 0.51; 95% CI, 0.39-0.67), and the composite of myocardial infarction, stroke, and death (OR, 0.45; 95% CI, 0.29-0.70). No significant differences in cardiovascular mortality (OR, 0.82; 95% CI, 0.41-1.63) and the incidence of kidney injury (OR, 0.90; 95% CI, 0.58-1.39) between the groups were identified., Conclusions: Our analysis demonstrated that statin therapy is beneficial in improving operative and interventional outcomes and should be considered as part of the optimization strategy for prevention of adverse cardiovascular and cerebrovascular events and death., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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28. Computational fluid dynamic analysis of the effect of morphologic features on distraction forces in fenestrated stent grafts.
- Author
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Jones SM, Poole RJ, How TV, Williams RL, McWilliams RG, Brennan JA, Vallabhaneni SR, and Fisher RK
- Subjects
- Aorta, Abdominal diagnostic imaging, Aorta, Abdominal physiopathology, Aortic Aneurysm, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal physiopathology, Aortography methods, Arterial Pressure, Blood Flow Velocity, Blood Vessel Prosthesis Implantation adverse effects, Endovascular Procedures adverse effects, Foreign-Body Migration etiology, Foreign-Body Migration physiopathology, Humans, Prosthesis Design, Prosthesis Failure, Stress, Mechanical, Tomography, X-Ray Computed, Treatment Outcome, Aorta, Abdominal surgery, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Computer Simulation, Endovascular Procedures instrumentation, Hemodynamics, Models, Cardiovascular, Stents
- Abstract
Objective: Secure fixation of endovascular stent grafts is essential for successful endovascular aneurysm repair. Hemodynamic distraction forces are generated by blood pressure and blood flow and act against fixation force to encourage migration that may eventually lead to late stent graft failure. The aim of this in silico study was to determine which morphologic features were associated with greater distraction force., Methods: Computer models of 54 in situ fenestrated stent grafts were constructed from postoperative computed tomography scans by use of image processing software. Computational fluid dynamic analysis was then performed by use of a commercial finite volume solver with boundary conditions representative of peak systole. Distraction force results were obtained for each component of the stent graft. Distraction force was correlated with lumen cross-sectional area (XSA) at the inlet and outlet of components and was compared between groups of components, depending on the magnitude of four predefined angles within the aortoiliac territory that we describe in detail., Results: Median total resultant distraction force (RDF) acting on the fenestrated proximal bodies was 4.8 N (1.3-15.7 N); bifurcated distal bodies, 5.6N (1.0-8.0 N); and limb extensions, 1.7 N (0.6-8.4N). Inlet XSA exhibited strong, positive correlation with total RDF in proximal body and distal body components (Spearman correlation coefficient ρ, 0.883 and 0.802, respectively). Outlet XSA exhibited a similarly strong, positive correlation with total RDF in limb extension components (ρ, 0.822). Outlet angulation ≥ 45 degrees was associated with greater total RDF in the limb extension components only (P = .004)., Conclusions: For a given blood pressure, XSA was the most important morphologic determinant of total RDF. Angulation within the aorta was not large enough to influence this, whereas iliac angulation affecting outlet angulation of limb extension components was associated with significantly greater total RDF., (Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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29. Type IIIb endoleak is an important cause of failure following endovascular aneurysm repair.
- Author
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Jones SM, Vallabhaneni SR, McWilliams RG, Naik J, Nicholas T, and Fisher RK
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal diagnosis, Aortic Rupture etiology, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Device Removal, Endoleak diagnosis, Endoleak surgery, Endovascular Procedures instrumentation, Fatal Outcome, Humans, Male, Prosthesis Design, Reoperation, Stents, Treatment Failure, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation adverse effects, Endoleak etiology, Endovascular Procedures adverse effects, Prosthesis Failure
- Abstract
Purpose: To present confirmed cases of type IIIb endoleak in second and third-generation stent-grafts used for endovascular aneurysm repair (EVAR)., Case Reports: Four patients developed type IIIb endoleak caused by fabric tears between 4 and 13 years following their initial EVAR. Three patients presented with rupture and one with aneurysm expansion of unknown cause. In each case, the type IIIb endoleak was confirmed at open surgery after imaging proved non-diagnostic. Only one patient survived. Had the cause for the expansion or ruptures been found prior to open reintervention, relining of the stent-graft may have been possible., Conclusion: Type IIIb endoleak remains difficult to diagnose. Avoidance of the high mortality associated with open secondary intervention requires a high degree of suspicion and it should be considered in any post-EVAR aneurysm expansion without an obvious cause.
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- 2014
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30. Closure technique after carotid endarterectomy influences local hemodynamics.
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Harrison GJ, How TV, Poole RJ, Brennan JA, Naik JB, Vallabhaneni SR, and Fisher RK
- Subjects
- Adult, Aged, Aged, 80 and over, Blood Flow Velocity, Carotid Arteries diagnostic imaging, Carotid Arteries physiopathology, Carotid Artery Diseases diagnosis, Carotid Artery Diseases physiopathology, Computer Simulation, Equipment Design, Female, Humans, Male, Middle Aged, Models, Cardiovascular, Pulsatile Flow, Regional Blood Flow, Reproducibility of Results, Stress, Mechanical, Treatment Outcome, Ultrasonography, Angioplasty adverse effects, Angioplasty instrumentation, Carotid Arteries surgery, Carotid Artery Diseases surgery, Endarterectomy, Carotid, Hemodynamics, Wound Closure Techniques adverse effects
- Abstract
Background: Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection., Methods: Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of <0.4 Pa and OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared., Results: The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width., Conclusions: Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8-mm patch and may be the preferred option., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2014
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31. Defining a role for contrast-enhanced ultrasound in endovascular aneurysm repair surveillance.
- Author
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Millen A, Canavati R, Harrison G, McWilliams RG, Wallace S, Vallabhaneni SR, and Fisher RK
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal diagnostic imaging, Aortography methods, Endoleak etiology, Endoleak therapy, Female, Graft Occlusion, Vascular etiology, Graft Occlusion, Vascular therapy, Humans, Male, Predictive Value of Tests, Prospective Studies, Tertiary Care Centers, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Vascular Patency, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation adverse effects, Contrast Media, Endoleak diagnostic imaging, Endovascular Procedures adverse effects, Graft Occlusion, Vascular diagnostic imaging, Phospholipids, Sulfur Hexafluoride, Ultrasonography, Doppler, Duplex
- Abstract
Objective: Endovascular aneurysm repair (EVAR) surveillance includes duplex ultrasound, abdominal radiography, and computed tomography angiography. Contrast-enhanced ultrasound (CEUS) has emerged as an additional modality whose role remains undefined. We evaluated whether a potential role for CEUS was the elucidation of unresolved issues following standard surveillance modalities., Methods: All patients undergoing EVAR at a tertiary referral center had surveillance based on plain abdominal radiograph and duplex ultrasound, with single arterial phase computed tomography angiography reserved for abnormalities or nondiagnostic imaging. In this prospective evaluation, from April 2010 to July 2011, discordance between imaging modalities or unresolved surveillance issues prompted CEUS. Cases and imaging were discussed in a multidisciplinary setting and outcomes recorded., Results: During the study period, 539 patients underwent EVAR surveillance, of whom 33 (6%) had CEUS for unresolved issues (median age, 79; range, 66-90; 28 male). Median follow-up after EVAR was 23 months (range, 0-132). In all cases, CEUS was able to resolve the clinical issue, resulting in secondary intervention in 10 patients (30%). The remaining patients were returned to surveillance. Within the cohort of 33 patients, the clinical issues were categorized into three groups. Group 1: Endoleak of uncertain classification (n = 27: 21 type II, four type I, two had endoleak excluded). Group 2: Significant aneurysm expansion (≥ 5 mm) without apparent endoleak (n = 4: one type II, three had endoleak excluded). Group 3: Target vessel patency following fenestrated EVAR (n = 2: patency confirmed in both)., Conclusions: CEUS can enhance EVAR surveillance through clarification of endoleak and target vessel patency when standard imaging modalities are not diagnostic., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2013
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32. Migration of fenestrated aortic stent grafts.
- Author
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England A, García-Fiñana M, Fisher RK, Naik JB, Vallabhaneni SR, Brennan JA, and McWilliams RG
- Subjects
- Aged, Female, Foreign-Body Migration complications, Foreign-Body Migration epidemiology, Humans, Incidence, Male, Prospective Studies, Prosthesis Design, Aortic Aneurysm, Abdominal surgery, Foreign-Body Migration etiology, Stents adverse effects
- Abstract
Objective: This article reports the incidence, timing, and related sequelae for proximal and distal migration of the Zenith Fenestrated AAA Endovascular Graft (Cook Medical, Bloomington, Ind) used to treat abdominal aortic aneurysms., Method: A prospectively maintained database at a tertiary referral hospital was used to identify 83 patients who underwent endovascular repair using the Zenith fenestrated stent graft. Inclusion criteria included a postoperative computed tomography (CT) scan within 6 weeks of implantation and at least one additional follow-up CT scan (>5 months) available electronically at our institution. Eligible patients underwent assessment of stent graft migration using a CT-based central luminal line (CLL) technique. The proximal and distal margins of the stent graft were measured using CLLs relative to vascular landmarks on all available follow-up CT scans. Migration was defined as stent graft movement ≥4 mm., Results: Fifty-five patients were included in this study, mean age was 74 ± 7 years, and 89% were men. Mean preoperative aneurysm diameter was 67 ± 9 mm. In these 55 patients, fenestrations were applied to 162 target vessels with the commonest design accommodating two renal arteries (RAs) and the superior mesenteric artery (SMA). Median follow-up was 24 (range, 5-97) months; 80% of patients (n = 44) had both the proximal and two distal attachment sites assessed for evidence of migration. Twelve iliac limbs in 11 patients were excluded from analysis due to occlusion of one internal iliac artery precluding CLL assessment (n = 7), or image quality issues (n = 5). Using CLLs and based on those patients who exhibited migration, the median proximal and distal migration distances were +5.0 (range, +4.0 to +8.1) mm and -5.0 (range, -4.3 to -21.3) mm, respectively. Kaplan-Meier analysis for proximal migration revealed migration rates of 14% and 22% at 12 and 36 months, respectively. Distal migration rates were lower at 3% and 8%, respectively. There have been no incidences of late rupture or open conversion. Of the patients with proximal migration, two patients lost a single target vessel (two RAs) and three patients were reported to have target vessel stenosis (two SMAs, one RA). These cases did not require reintervention., Conclusions: Both suprarenal fabric extension and visceral artery stenting are known to provide additional fixation for fenestrated aortic stent grafts. Despite this, minor proximal migration still occurs in up to one quarter of fenestrated endovascular repair patients by 4 years. We believe this is mainly due to the engagement of the barbs of the anchoring stent. Distal migrations occur with lower frequency., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2013
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33. Combined cardiac surgery and endovascular repair of abdominal aortic aneurysms.
- Author
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Field ML, Vallabhaneni SR, Kuduvalli M, Brennan JA, Torella F, McWilliams RG, and Oo A
- Subjects
- Aged, Humans, Male, Middle Aged, Retrospective Studies, Aortic Aneurysm, Abdominal complications, Aortic Aneurysm, Abdominal surgery, Coronary Artery Bypass, Coronary Artery Disease complications, Coronary Artery Disease surgery, Endovascular Procedures
- Abstract
Purpose: To report an initial experience of concomitant endovascular repair of abdominal aortic aneurysms (AAA) and cardiac surgery., Methods: Records for 10 consecutive patients (all men; median age 68 years, range 60-79) with AAA treated by a multidisciplinary team at a tertiary specialist center were retrospectively reviewed. Each patient had independent indications for surgical correction of their cardiac disease and AAAs. The patients underwent endovascular aneurysm repair (EVAR) followed by cardiac surgery under the same anesthesia. Eight patients had concomitant coronary artery bypass grafting (CABG; 4 off-pump), 1 patient had CABG and left ventricular aneurysmectomy, and 1 patient required aortic root replacement., Results: All combined procedures were performed successfully under a single general anesthesia and took a median of 508 minutes (range 425-625). Median intensive care stay was 3 days (range 2-4), while hospital stay was 8 days (range 7-21) days. There were no deaths in-hospital or within 30 days. Complications were minor and self-limiting; there were no instances of renal failure. At a median follow-up of 29 months (range 14-38), no EVAR-related secondary interventions were required., Conclusion: Concomitant EVAR and cardiac surgery delivered by a multidisciplinary team is feasible, appears safe, and eliminates the risk associated with staged operations. Improved patient satisfaction and efficient use of resources are potential advantages.
- Published
- 2013
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34. Fractured superior mesenteric artery stents after fenestrated endovascular aneurysm repair.
- Author
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Canavati R, How TV, Brennan JA, Vallabhaneni SR, Fisher RK, and McWilliams RG
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal diagnostic imaging, Aortography, Blood Vessel Prosthesis Implantation adverse effects, Device Removal, Embolism etiology, Embolism therapy, Endovascular Procedures adverse effects, Humans, Male, Mesenteric Artery, Superior diagnostic imaging, Mesenteric Vascular Occlusion etiology, Mesenteric Vascular Occlusion prevention & control, Prosthesis Design, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Endovascular Procedures instrumentation, Mesenteric Artery, Superior surgery, Prosthesis Failure, Stents
- Abstract
Stent fracture after fenestrated endovascular aneurysm repair is a recognized complication. In this report, we record the occurrence of superior mesenteric artery stent fractures in our series and describe the management of embolized stent fragments during secondary intervention., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2013
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35. Comparison of fenestrated endovascular and open repair of abdominal aortic aneurysms not suitable for standard endovascular repair.
- Author
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Canavati R, Millen A, Brennan J, Fisher RK, McWilliams RG, Naik JB, and Vallabhaneni SR
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal mortality, Aortography methods, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation mortality, Endovascular Procedures adverse effects, Endovascular Procedures mortality, England, Female, Hospital Mortality, Humans, Length of Stay, Male, Middle Aged, Postoperative Complications surgery, Prosthesis Design, Reoperation, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Endovascular Procedures instrumentation, Stents
- Abstract
Background: Abdominal aortic aneurysms that are unsuitable for a standard endovascular repair (EVAR) could be considered for fenestrated endovascular repair (f-EVAR). The aim of this study was to conduct a risk-adjusted retrospective concurrent cohort comparison of f-EVAR and open repair for such aneurysms., Methods: All patients who underwent repair of an abdominal aortic aneurysm that was unsuitable for a standard EVAR due to inadequate neck within one institution between January 2006 and December 2010 were identified. Case notes were retrieved for clinical data, Vascular Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (V-POSSUM) score, and aneurysm morphology. Computed tomography scans were reviewed to establish aneurysm morphology., Results: A total of 107 patients were identified. The open surgery cohort included 54 patients (35 men) who were a median age of 72 years (interquartile range [IQR], 9.5; range, 60-86 years). The aortic cross-clamp was infrarenal in 20 patients, suprarenal or above in 21, and inter-renal in eight. Postoperatively, 63 major complications were noted in 30 patients, nine of whom required 16 reinterventions. Cumulative hospital stay of the cohort was 1170 days (median, 12; IQR, 13; range, 1-205 days) of which 234 days (median, 28; IQR, 36; range, 1-77 days) were in the intensive therapy unit (ITU). Perioperative mortality was 9.2% (n = 5), exactly as estimated by V-POSSUM. The f-EVAR cohort included 53 patients (47 men) who were a median age of 76 years (IQR, 11.50; range, 55-87 years). Two fenestrations and one scallop was the most frequent configuration (n = 31). Postoperatively, 37 major complications were noted in 18 patients, six requiring reintervention. Hospital stay was 559 days (median, 7; IQR, 4.5; range, 4-64 days), of which 31 days (median, 4; IQR, 10.5; range, 1-15 days) were in the ITU. Two patients died perioperatively (3.7%), resulting in an observed crude absolute risk reduction of 5.5% compared with open repair. The V-POSSUM estimated perioperative death in five patients (9.4%) in the f-EVAR cohort. In a hypothetic scenario of the f-EVAR cohort undergoing open repair, V-POSSUM estimated seven deaths (13.2%), resulting in an estimated risk-adjusted absolute risk reduction due to f-EVAR of 9.5%., Conclusions: In this group of patients, f-EVAR reduced mortality and morbidity substantially compared with open repair and also reduced total hospital stay and ITU utilization., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2013
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36. Final follow-up of the Multicentre Aneurysm Screening Study (MASS) randomized trial of abdominal aortic aneurysm screening (Br J Surg 2012; 99: 1649-1656).
- Author
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Vallabhaneni SR
- Subjects
- Humans, Male, Aortic Aneurysm, Abdominal mortality, Aortic Rupture mortality
- Published
- 2012
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37. Anchoring barbs and balloon expandable stents: what is the risk of perforation and failed stent deployment?
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Bown MJ, Harrison GJ, How TV, Brennan JA, Fisher RK, Vallabhaneni SR, and McWilliams RG
- Subjects
- Arteries anatomy & histology, Equipment Failure Analysis, Humans, Materials Testing, Models, Anatomic, Pressure, Prosthesis Design, Risk Assessment, Risk Factors, Time Factors, Angioplasty, Balloon adverse effects, Angioplasty, Balloon instrumentation, Arteries surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation instrumentation, Prosthesis Failure, Stents
- Abstract
Purpose: Balloon expandable stents may on occasion be deployed in close proximity to the anchoring barbs of endovascular grafts. The aim of this study was to determine the risk and effect of balloon perforation by anchoring barbs and to assess whether these risks are different if the balloon is protected by a covered stent mounted upon it., Methods: A bench-top model was developed to mimic the penetration of anchoring barbs into the lumen of medium sized blood vessels. The model allowed variation of angle and depth of vessel penetration. Both bare balloons and those with covered stents mounted upon them were tested in the model to determine whether there was a risk of perforation and which factors increased or decreased this risk., Results: All combinations of barb angle and depth caused balloon perforation but this was most marked when the barb was placed perpendicular to the long axis of the balloon. When the deployment of covered stents was attempted balloon perforation occurred in some cases but full stent deployment was achieved in all cases where the perforation was in the portion of the balloon covered by the stent. The only situation in which stent deployment failed was where the barb was intentionally placed in the uncovered portion of the balloon. This resulted in only partial deployment of the stent., Conclusions: Balloon rupture is a distinct possibility when deploying balloon-expandable stents in close proximity to anchoring barbs. Care should be taken in this circumstance to ensure that the barb is well away from the uncovered portion of the balloon., (Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2012
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38. The accuracy of computed tomography central luminal line measurements in quantifying stent graft migration.
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England A, García-Fiñana M, How TV, Vallabhaneni SR, and McWilliams RG
- Subjects
- Adult, Aged, Aortic Aneurysm therapy, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation methods, Cardiac Catheterization methods, Female, Humans, Male, Middle Aged, Models, Anatomic, Observer Variation, Phantoms, Imaging, Sensitivity and Specificity, Aortic Aneurysm diagnostic imaging, Foreign-Body Migration diagnostic imaging, Multidetector Computed Tomography methods, Prosthesis Failure, Stents
- Abstract
Purpose: This study evaluated the accuracy of central luminal line (CLL) measurements in quantifying stent graft migration. The bias of the CLL technique together with observer variability were assessed., Methods: Stent grafts were deployed in plastic aortic phantoms at fixed locations from two side branches. Each phantom was filled with iodinated contrast, and a 2-mm multislice computed tomography (CT) scan was performed. The stent graft was then displaced caudally, its new location determined, and again, a CT scan performed. This created a series of 15 cases with known stent graft migration. CLLs were used to measure stent graft position on the CT scans and calculate migration (3 observers). In vivo stent graft migration was then evaluated in a similar manner using a series of follow-up CT scans from nine patients (2 observers). All CLL measurements were performed independently and were repeated on a separate occasion., Results: The mean difference in CLL migration between the actual and observed measurements (bias) in the aortic phantoms was <1 mm. The 95% confidence intervals for the bias were within the interval (-1 and 1 mm), and the 95% limits of agreement were within -3 mm and +3 mm. The 95% limits of agreement for measurements within and between observers were -4 to 2 mm and -2 to 2 mm, respectively. The phantom study generated a coefficient of repeatability (RC) of 1 mm for within-observer measurements. Clinically, CLLs generated 95% limits of agreement within and between observers of -3 to 4 mm (RC, 2 mm) and -3 to +3 mm, respectively., Conclusions: Bias from CLL-determined migration is small and insignificant from a practical point of view. A small amount of measurement variability within and between observers does exist; it should be feasible to detect changes in stent graft position that are ≥4 mm., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2012
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39. Guidewire stiffness: what's in a name?
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Harrison GJ, How TV, Vallabhaneni SR, Brennan JA, Fisher RK, Naik JB, and McWilliams RG
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- Blood Vessel Prosthesis, Endovascular Procedures instrumentation, Materials Testing, Pliability
- Abstract
Purpose: To measure the stiffness of commonly used "stiff" guidewires in terms of their flexural modulus, an engineering parameter related to bending stiffness., Methods: Eleven different intact stiff guidewires were selected to undergo a 3-point bending test performed using a tensile testing machine. Testing was performed on 3 new and intact specimens of each guidewire at 10 locations along the wire's length, excluding the floppy tip. The flexural modulus (in gigapascals, GPa) was calculated from the results of the bending test., Results: The flexural modulus of the plain Amplatz wire was 9.5 GPa compared to 11.4 to 14.5 GPa for the "heavy duty" wires. Within the Amplatz family of guidewires, the flexural modulus was 17 GPa for the "stiff," 29.2 GPa for the "extra stiff," 60.3 GPa for the "super stiff," and 65.4 GPa for the "ultra stiff." The Backup Meier measured 139.6 GPa and the Lunderquist Extra Stiff 158.4 GPa., Conclusion: The Instructions for Use of some endovascular devices specify a wire type selected from a range of undefined "stiffness" descriptors. These descriptors have little correlation with the measured flexural modulus. Two guidewires with the description "extra stiff" can have a 5-fold difference in flexural modulus. We recommend that guidewire catalogues and packaging include the flexural modulus and that device manufacturers amend their Instructions for Use accordingly.
- Published
- 2011
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40. Use of a superficial femoral artery autograft as a femoral vein replacement during en bloc sarcoma resection.
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Ghosh J, Naik J, Chandrasekar C, Yin Q, and Vallabhaneni SR
- Subjects
- Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Femoral Vein pathology, Humans, Liposarcoma, Myxoid pathology, Male, Middle Aged, Neoplasm Invasiveness, Polytetrafluoroethylene, Prosthesis Design, Soft Tissue Neoplasms pathology, Tomography, X-Ray Computed, Transplantation, Autologous, Treatment Outcome, Femoral Artery transplantation, Femoral Vein surgery, Liposarcoma, Myxoid surgery, Soft Tissue Neoplasms surgery
- Abstract
Introduction: Soft tissue malignancy encasing axial vessels presents a surgical challenge when the goal is limb-preserving radical excision., Report: We describe a case where limb-preserving resection of a myxoid liposarcoma involving the femoral vessels was successfully performed in the absence of autologous superficial vein for vascular reconstruction. The proximal ipsilateral superficial femoral artery was harvested as an autograft for venous reconstruction, with the arterial defect bridged using a polytetrafluoroethylene interposition graft., Discussion: This technique may be selectively extended to other indications where limb viability is dependent upon availability of a high-quality graft, and conventional conduits are either unavailable or unreliable.
- Published
- 2011
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41. Surveillance after EVAR based on duplex ultrasound and abdominal radiography.
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Harrison GJ, Oshin OA, Vallabhaneni SR, Brennan JA, Fisher RK, and McWilliams RG
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm diagnosis, Aortic Aneurysm economics, Aortography adverse effects, Aortography economics, Cost Savings, Cost-Benefit Analysis, England, Female, Hospital Costs, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Postoperative Care, Postoperative Complications diagnostic imaging, Postoperative Complications economics, Postoperative Complications therapy, Predictive Value of Tests, Radiation Dosage, Reoperation, Retrospective Studies, Time Factors, Treatment Outcome, Unnecessary Procedures economics, Aortic Aneurysm surgery, Aortography methods, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation economics, Endovascular Procedures adverse effects, Endovascular Procedures economics, Postoperative Complications diagnosis, Tomography, X-Ray Computed adverse effects, Tomography, X-Ray Computed economics, Ultrasonography, Doppler, Duplex economics
- Abstract
Introduction: Computed tomography angiography (CTA) is considered the gold standard imaging technique for surveillance following endovascular aneurysm repair (EVAR). Limitations of CTA include cost, risk of contrast nephropathy and radiation exposure. A modified surveillance protocol involving annual duplex ultrasound (DUS) and abdominal radiography (AXR) was introduced, with CTA performed only if abnormalities were identified or DUS was undiagnostic., Methods: Prospective records were maintained on patients undergoing infra-renal EVAR at a UK, tertiary referral centre. All patients enrolled with at least one-year follow-up were reviewed. Primary outcomes identified were aneurysm rupture and aneurysm-related complications. Secondary outcomes included number of CTAs avoided and cost., Results: Median follow-up was 36 months (range 12-57) for 194 patients. The total number of sets of surveillance imaging was 412 of which 70 (17%) required CTA. Abnormalities were found in 30 patients, 18 confirmed by CTA. Eleven patients required secondary intervention, three initially identified by AXR, three by DUS, three by both DUS and AXR, and two by CTA following undiagnostic DUS. No patient presented with rupture or aneurysm-related complications not identified by modified surveillance. Mean annual savings were €223., Conclusion: EVAR surveillance based on DUS and AXR is feasible and safe. The complimentary nature of AXR and DUS is demonstrated., (Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
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42. Magnitude of the forces acting on target vessel stents as a result of a mismatch between native aortic anatomy and fenestrated stent-grafts.
- Author
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Oshin OA, How TV, Brennan JA, Fisher RK, McWilliams RG, and Vallabhaneni SR
- Subjects
- Animals, Aorta anatomy & histology, Biomechanical Phenomena, Blood Vessel Prosthesis Implantation adverse effects, Elasticity, Endovascular Procedures adverse effects, Friction, Materials Testing, Models, Animal, Prosthesis Design, Stress, Mechanical, Swine, Tensile Strength, Aorta surgery, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Endovascular Procedures instrumentation, Hemodynamics, Stents
- Abstract
Purpose: To quantify the compression force acting on target vessel stents as a consequence of the misalignment between the native aortic anatomy and the fenestrated stent-graft owing to measuring errors during the design of the device., Methods: The material properties of a fenestrated Zenith stent-graft were determined using a standardized tensile testing protocol. Aortic anatomy was modeled using fresh porcine aortas that were subjected to tensile testing. The net force acting on a target vessel stent due to incremental discrepancy between the target vessel ostia and the stent-graft fenestrations was calculated as the difference in wall tension between the aorta and the stent-graft in diastole and systole. The change in diameter between diastole and systole was set to 8%., Results: Using the diastole model, underestimation of circumferential target vessel position by 15°, 22.5°, and 30° resulted in net forces on the target vessel stent of 0.6, 0.8, and 1.1 N, respectively. Overestimation of target vessel position by the same increments resulted in net forces of 0.3, 0.6, and 0.9 N, respectively. With the systolic model, underestimating target vessel position by 30° resulted in a 2.1-N maximum force on the stent, which potentially threatened the seal. In the longitudinal direction, underestimating target vessel separation by up to 10 mm resulted in a maximal force on the stent of 6.1 N, while overestimating target vessel separation did not result in any additional force on the stent due to fabric infolding., Conclusion: The magnitude of the forces generated solely due to mismatch between stent-graft design and native anatomy is modest and is unlikely to cause significant deformation of target vessel stents. Mismatch, however, may cause loss of seal.
- Published
- 2011
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43. Pragmatic minimum reporting standards for endovascular abdominal aortic aneurysm repair.
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Boyle JR, Thompson MM, Vallabhaneni SR, Bell RE, Brennan JA, Browne TF, Cheshire NJ, Hinchliffe RJ, Jenkins MP, Loftus IM, Macdonald S, McCarthy MJ, McWilliams RG, Morgan RA, Oshin OA, Pemberton RM, Pillay WR, and Sayers RD
- Subjects
- Age Factors, Aortic Aneurysm, Abdominal diagnosis, Aortic Aneurysm, Abdominal mortality, Aortic Rupture diagnosis, Aortic Rupture mortality, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation adverse effects, Blood Vessel Prosthesis Implantation instrumentation, Blood Vessel Prosthesis Implantation mortality, Comorbidity, Endovascular Procedures adverse effects, Endovascular Procedures instrumentation, Endovascular Procedures mortality, Female, Humans, Kidney physiopathology, Male, Prosthesis Design, Risk Assessment, Risk Factors, Sex Factors, Stents, Treatment Outcome, Aortic Aneurysm, Abdominal surgery, Aortic Rupture surgery, Blood Vessel Prosthesis Implantation standards, Endovascular Procedures standards, Evidence-Based Emergency Medicine standards, Outcome and Process Assessment, Health Care standards, Quality Indicators, Health Care standards
- Published
- 2011
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44. Fascial closure following percutaneous endovascular aneurysm repair.
- Author
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Harrison GJ, Thavarajan D, Brennan JA, Vallabhaneni SR, McWilliams RG, and Fisher RK
- Subjects
- Aged, Aged, 80 and over, Aneurysm, False etiology, England, Female, Femoral Artery diagnostic imaging, Hemorrhage etiology, Humans, Male, Middle Aged, Punctures, Thrombosis etiology, Time Factors, Treatment Outcome, Ultrasonography, Doppler, Duplex, Aortic Aneurysm surgery, Blood Vessel Prosthesis Implantation adverse effects, Endovascular Procedures adverse effects, Fasciotomy, Femoral Artery surgery, Hemorrhage prevention & control, Hemostatic Techniques adverse effects, Wound Closure Techniques adverse effects
- Abstract
Introduction: There are potential benefits of percutaneous over open femoral access for endovascular aneurysm repair (EVAR). Subsequent arterial closure using percutaneous devices is costly, whilst open repair risks potential wound complications and delayed discharge. The technique of fascial closure has perceived advantages but its efficacy is unclear. The aim of this study was to assess the safety and durability of fascial closure after EVAR., Methods: Patients undergoing EVAR using devices up to 24 French were considered. Exclusion criteria included morbid obesity, high bifurcation, previous surgery, inadvertent high puncture, arteries < 5 mm and surgeon preference. The primary outcome measure was immediate technical success. All patients were followed-up clinically and with duplex at one and twelve months to determine secondary complications., Results: Over a one-year period fascial closure of 69 common femoral arteries was attempted in 38 patients undergoing EVAR. Nine primary failures were due to haemorrhage in eight arteries and thrombosis in one artery; all had immediate, uncomplicated open revision. Of the 60 (87%) successful procedures, all had duplex surveillance at one month. Four pseudoaneurysms were identified, all treated conservatively. At one year, 61 fascial closures (88%) were imaged, four patients had died and two were lost to follow-up. Three of the pseudoaneurysms had resolved, the fourth patient had died (unrelated). No other complication attributable to fascial closure was found at either one or twelve months., Conclusion: Fascial closure is a safe, durable and cost-effective method of arterial closure following EVAR. Success and complication rates are comparable to other techniques., (Copyright © 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
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45. Intra- and interobserver variability of target vessel measurement for fenestrated endovascular aneurysm repair.
- Author
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Oshin OA, England A, McWilliams RG, Brennan JA, Fisher RK, and Vallabhaneni SR
- Subjects
- Chi-Square Distribution, England, Humans, Observer Variation, Patient Selection, Predictive Value of Tests, Prosthesis Design, Reproducibility of Results, Aortic Aneurysm diagnostic imaging, Aortic Aneurysm surgery, Aortography methods, Blood Vessel Prosthesis, Blood Vessel Prosthesis Implantation instrumentation, Radiographic Image Interpretation, Computer-Assisted, Stents, Tomography, X-Ray Computed
- Abstract
Purpose: To evaluate intra- and interobserver agreement of target vessel measured from computed tomography (CT) scans with 2 measuring techniques used in planning fenestrated endovascular aneurysm repairs (FEVAR): multiplanar reconstruction (MPR) and semi-automated central lumen line (CLL)., Methods: CT datasets from 25 FEVAR patients were independently analyzed by 2 experienced observers according to a standardized protocol using the MPR (Leonardo workstation) and CLL (Aquarius workstation) techniques for each patient. Longitudinal vessel separation and clock-face position of the visceral aortic branches were measured twice. The repeatability coefficient (RC) was calculated using the Bland and Altman method to measure intra- and interobserver variability. Differences between groups were examined by paired t test (continuous data) or chi-squared analysis (categorical). Clock-face discrepancy >30 minutes was considered significant., Results: Intraobserver mean difference was insignificant regardless of the measurement technique: the observer and workstation-specific RCs varied between 3.9 and 4.9 mm. Paired measurements differed by >3 mm in 8%. Interobserver variability was greater: observer and workstation-specific RC varied between 5.6 and 7.4 mm, with a tendency toward consistency using MPR, although the mean difference was insignificant. Paired measurements differed by >3 mm in 18%. There was no significant intraobserver variation in clock-face measurement, while interobserver variation was significant in 12% of measurements using the Aquarius workstation and 6% using the Leonardo workstation (p = 0.19)., Conclusion: Subjective interpretation of anatomical landmarks is more important than measurement techniques or workstations used in the generation of measurement inconsistencies. Introduction of consensus regarding interpretation of anatomical detail and development of fenestrated stent-grafts tolerant of measurement errors might ameliorate some of the problems encountered in FEVAR.
- Published
- 2010
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46. Optimal technique for imaging iliac segments during endovascular repair of abdominal aortic aneurysms.
- Author
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Oshin OA, Bown MJ, McWilliams RG, Brennan JA, and Vallabhaneni SR
- Subjects
- Angioplasty, Balloon, Blood Vessel Prosthesis Implantation, Humans, Observer Variation, Retrospective Studies, Stents, Angiography, Aortic Aneurysm, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal surgery, Iliac Artery diagnostic imaging, Imaging, Three-Dimensional, Tomography, X-Ray Computed
- Abstract
Purpose: To determine if oblique angulation of the image intensifier is adequate to image the entire length of the common iliac artery during endovascular aneurysm repair or if additional caudal tilt is necessary., Methods: Using a 3D workstation, the apparent level of the iliac bifurcation (distal limit of the stent-graft) was determined on computed tomographic angiography by profiling the common iliac segment in oblique angulation only and repeated with a combination of oblique angulation and caudal tilt. Two independent observers measured twice the apparent length of the iliac segment in both profiles for 50 patients according to a set protocol. Intra- and interobserver variability was calculated using the Bland and Altman method; the differences between the two different profiles were tested using paired t tests., Results: Of the 50 CTA datasets reviewed, 2 datasets were excluded owing to extensive calcification of the iliac system that prevented accurate interpretation of the image. Of the 96 segments studied, the iliac segments appeared longer (better profiled) with a combination of caudal tilt and oblique angulation in 80%, with an average discrepancy of 9 mm for observer 1 (range -1 to +28) and 7 mm for observer 2 (0 to +26). The effect of caudal tilt was statistically significant for individual observers (p = 0.001 and 0.024, respectively). Forty-six percent of iliac segments measured by observer 1 and 35% by observer 2 showed that the addition of caudal tilt resulted in improved profiling by at least 10 mm. Although inter- and intraobserver variation was significant, the gain in apparent iliac length with the addition of caudal tilt was preserved., Conclusion: When profiled with oblique angulation alone, the location of the iliac bifurcation may appear higher than its true location, resulting in underutilization of the iliac segment by >10 mm in over a third of the patients. The problem is corrected by employing additional caudal tilt.
- Published
- 2009
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47. www.Accurate information for varicose vein patients.com?
- Author
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Scurr JR, Hufton A, Jeffrey V, and Vallabhaneni SR
- Subjects
- Humans, United Kingdom, Information Dissemination methods, Internet standards, Patient Education as Topic standards, Varicose Veins therapy
- Abstract
Introduction: The aim of this study was to review the information available to the public regarding the treatment of varicose veins on dedicated UK-based websites., Patients and Methods: Websites were identified by using the Google search engine. All identified websites were examined, noting the range of treatments explained and their stated potential complications. Website ownership was also recorded., Results: A total of 49 websites were identified, belonging to individual physicians (21), private clinics or groups (15), national institutions (4) and device/drug manufacturers (4). Five websites were simply redirecting portals and, hence, were excluded from further analysis. Treatment methods discussed were conventional surgery (32), endovenous laser [EVLA] and/or radiofrequency ablation [RFA] (31), and ultrasound-guided foam sclerotherapy [UGFS] (27). Only 19 websites (43%) discussed all treatment methods. Complications mentioned following surgery were: cutaneous nerve damage (56%), recurrence (56%), infection (53%), bleeding (41%) and venous thrombo-embolism (38%). Complications following EVLA/RFA were: cutaneous nerve damage (42%), recurrence (42%), venous thrombo-embolism (39%) and burns (35%). Complications following UGFS were: pigmentation (59%), venous thrombo-embolism (48%), ulceration (41%), recurrence (41%), allergy (26%) and visual disturbance (26%)., Conclusions: Over 50% of the websites examined did not mention all the management methods now available for varicose veins. More importantly, the majority of the websites did not warn of the common complications of intervention. Currently, information on the Internet cannot be relied upon to supplement informed consent and may actually generate unrealistic patient expectations.
- Published
- 2008
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48. Wholly endovascular repair of thoracoabdominal aneurysm.
- Author
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Gilling-Smith GL, McWilliams RG, Scurr JR, Brennan JA, Fisher RK, Harris PL, and Vallabhaneni SR
- Subjects
- Adult, Aged, Anesthesia, General, Blood Vessel Prosthesis, Endarterectomy methods, Female, Follow-Up Studies, Hospital Mortality, Humans, Imaging, Three-Dimensional, Male, Middle Aged, Tomography, X-Ray Computed methods, Aortic Aneurysm, Thoracic surgery, Blood Vessel Prosthesis Implantation methods
- Abstract
Background: The aim was to evaluate a wholly endovascular approach to the repair of thoracoabdominal aortic aneurysm (TAAA)., Methods: Six patients (median age 71 years) underwent wholly endovascular repair of TAAA (maximum diameter 56-85 mm) employing individually customized endografts. Procedures were performed under general anaesthesia, with spinal drainage in five patients. Patients were followed by serial computed tomography, plain radiography and duplex imaging for a median of 17 (range 8-44) months., Results: All grafts were deployed as intended, with preservation of all target vessels. There were no postoperative deaths, strokes or paraplegia. One patient suffered a silent myocardial infarction. In two patients a persistent paraostial endoleak was treated by further balloon dilatation of the stent within the endograft fenestration. Imaging before discharge confirmed aneurysm exclusion in all patients. Two patients required late secondary intervention to abolish endoleaks due to side-branch disconnection. One patient suffered late occlusion of the coeliac axis without clinical sequelae, and late occlusion of a solitary renal artery in another resulted in dependence on dialysis. There have been no late deaths and all aneurysms remain excluded., Conclusion: Wholly endovascular TAAA repair is relatively safe, but long-term follow-up is required to establish its durability., (2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)
- Published
- 2008
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49. Measurement of pulsatile haemodynamic forces in a model of a bifurcated stent graft for abdominal aortic aneurysm repair.
- Author
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Zhou SN, How TV, Black RA, Vallabhaneni SR, McWilliams R, and Brennan JA
- Subjects
- Animals, Humans, Shear Strength, Stress, Mechanical, Aortic Aneurysm, Abdominal physiopathology, Aortic Aneurysm, Abdominal surgery, Blood Flow Velocity, Blood Pressure, Blood Vessel Prosthesis, Pulsatile Flow, Stents
- Abstract
The longitudinal haemodynamic force (LF) acting on a bifurcated stent graft for abdominal aortic aneurysm repair has been estimated previously using a simple one-dimensional analytical model based on the momentum equation which assumes steady flow of an inviscid fluid. Using an instrumented stent-graft model an experimental technique was developed to measure the LF under pulsatile flow conditions. The physical stent-graft model, with main trunk diameter of 30mm and limb diameters of 12 mm, was fabricated from aluminium. Strain gauges were bonded on to the main trunk to determine the longitudinal strain which is related to the LF. After calibration, the model was placed in a pulsatile flow system with 40 per cent aqueous glycerol solution as the circulating fluid. The LF was determined using a Wheatstone bridge signal-conditioning circuit. The signals were averaged over 590 cardiac cycles and saved to a personal computer for subsequent processing. The LF was strongly dependent on the pressure but less so on the flowrate. The measured forces were higher than those predicted by the simplified mathematical model by about 6-18 per cent during the cardiac cycle. The excess measured forces are due to the viscous drag and the effect of pulsatile flow. The peak measured LF in this model of 30 mm diameter may exceed the fixation force of some current clinical endovascular stent grafts.
- Published
- 2008
- Full Text
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50. Fenestrated endovascular repair for juxtarenal aortic aneurysm.
- Author
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Scurr JR, Brennan JA, Gilling-Smith GL, Harris PL, Vallabhaneni SR, and McWilliams RG
- Subjects
- Aged, Aged, 80 and over, Aortic Aneurysm, Abdominal pathology, Blood Vessel Prosthesis Implantation, Female, Hospital Mortality, Humans, Length of Stay, Male, Middle Aged, Surgical Flaps, Tomography, X-Ray Computed, Treatment Outcome, Vascular Patency, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis, Endoscopy methods, Stents
- Abstract
Background: The outcome of fenestrated endovascular aneurysm repair (F-EVAR) was evaluated., Methods: Between February 2003 and December 2006, 45 patients (median age 73 (range 53-85) years) underwent primary (41) or secondary (four) F-EVAR for an abdominal aortic aneurysm with infrarenal neck anatomy unsuitable for a standard stent-graft. Median aneurysm diameter was 68 (range 55-100) mm and median infrarenal aortic neck length was 6 (range 0-13) mm. Customized fenestrated Zenith stent-grafts were employed in all procedures, incorporating fenestrations to preserve flow into renal (80), superior mesenteric (35) and coeliac (two) arteries. Eighty-two target vessels were stented (61 bare metal, 21 covered)., Results: All aneurysms were isolated successfully, with preservation of the target vessels. One accessory renal artery was lost. One patient died after 5 days from myocardial infarction, and another at 3 months from multiorgan failure secondary to atheroembolism. At median follow-up of 24 (range 1-48) months, all aneurysms were stable or shrinking, with no late ruptures or graft-related endoleaks. Six patients required a secondary intervention. The primary vessel patency rate was 96.6 per cent. There were four late deaths, unrelated to the aneurysm., Conclusion: F-EVAR enabled successful treatment of juxtarenal aortic aneurysm with a low complication rate., (2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)
- Published
- 2008
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