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Introduction: It is assumed that identification and correction of asymptomatic stenoses in the vascular access circuit will prevent thrombosis that would require urgent intervention to continue hemodialysis treatment. However, the evidence base for this assumption is limited. Recent international clinical practice guidelines reach different conclusions on the use of surveillance for vascular access flow dysfunction and recommend further research to inform clinical practice., Methods: The FLOW trial is a double-blind, multicenter, randomized controlled trial with a 1:1 individual participant treatment allocation ratio over two study arms. In the intervention group, only symptomatic vascular access stenoses detected by clinical monitoring are treated, whereas in the comparison group asymptomatic stenoses detected by surveillance using monthly dilution flow measurements are treated as well. Hemodialysis patients with a functional arteriovenous vascular access are enrolled. The primary outcome is the access-related intervention rate that will be analyzed using a general linear model with Poisson distribution. Secondary outcomes include patient satisfaction, access-related serious adverse events, and quality of the surveillance process. A cost effectiveness analysis and budget impact analysis will also be conducted. The study requires 828 patient-years of follow-up in 417 participants to detect a difference of 0.25 access-related interventions per year between study groups., Discussion: As one of the largest randomized controlled trials assessing the clinical impact of vascular access surveillance using a strong double-blinded study design, we believe the FLOW trial will provide much-needed evidence to improve vascular access care for hemodialysis patients., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To describe outcomes after elective and non-elective fenestrated-branched endovascular aortic repair (FB-EVAR) for thoracoabdominal aortic aneurysms (TAAAs)., Background: FB-EVAR has been increasingly utilized to treat TAAAs; however, outcomes after non-elective versus elective repair are not well described., Methods: Clinical data of consecutive patients undergoing FB-EVAR for TAAAs at 24 centers (2006-2021) were reviewed. Endpoints including early mortality and major adverse events (MAEs), all-cause mortality, and aortic-related mortality (ARM), were analyzed and compared in patients who had non-elective versus elective repair., Results: A total of 2603 patients (69% males; mean age 72±10 year old) underwent FB-EVAR for TAAAs. Elective repair was performed in 2187 patients (84%) and non-elective repair in 416 patients [16%; 268 (64%) symptomatic, 148 (36%) ruptured]. Non-elective FB-EVAR was associated with higher early mortality (17% vs 5%, P <0.001) and rates of MAEs (34% vs 20%, P <0.001). Median follow-up was 15 months (interquartile range, 7-37 months). Survival and cumulative incidence of ARM at 3 years were both lower for non-elective versus elective patients (50±4% vs 70±1% and 21±3% vs 7±1%, P <0.001). On multivariable analysis, non-elective repair was associated with increased risk of all-cause mortality (hazard ratio, 1.92; 95% CI] 1.50-2.44; P <0.001) and ARM (hazard ratio, 2.43; 95% CI, 1.63-3.62; P <0.001)., Conclusions: Non-elective FB-EVAR of symptomatic or ruptured TAAAs is feasible, but carries higher incidence of early MAEs and increased all-cause mortality and ARM than elective repair. Long-term follow-up is warranted to justify the treatment., Competing Interests: Consulting, research grants and/or advisory boards: T.J. (Medical University of Warsaw)—Artivion, Cook Medical; B.C.M. (Mayo Clinic)—Cook Medical, WL Gore, Medtronic; T.K. (University of Hamburg)—Cook Medical; J.S.—(University of Lille)—Cookmedical, WLGore, GE Healthcare; L.B. (Hospital San Raffaelle)—Cook Medical; B.M. (Maastricht UMC)—Cook Medical, WL Gore, Phillips, Bentley; M.G. (University of Bologna-DIMEC)—Cook Medical, WL Gore; N.D. (Lund University)—Cook Medical; A.S. (University of Massachusetts)—Cook Medical, Philips, Artivion; A.B. (University of Alabama)—Artivion, Cook Medical, Medtronic, WL Gore, Terumo; K.M. (Uppsala university)—Cook Medical; M.F. (University of North Carolina)—Cook Medical, WL Gore, ViTaaa, Centerline, Getinge; C.T. (University of Texas Southwestern)—Cook Medical, WL Gore; D.B.S. (University of Pennsylvania)—Cook Medical, WL Gore, Endologix, Medtronic; N.T. (Ludwig-Maximilians-University Hospital)—Cook Medical; S.H. (Université Paris Saclay)—Cook Medical, Bentley, and GE healthcare; M.P.S. (University of Washington)—Artivion; E.F. (Universidade NOVA de Lisboa)—Cook Medical, Medtronic; M.E. (Harvard Medical School)—Cook Medical; K.K.Y. (Amsterdam UMC)—Medtronic, W.L. Gore&Associates, Terumo Aortic; G.P. (University of Hamburg)—Cook Medical, Philips; A.K. (Vita-Salute University)—Alvimedica/CID, Boston Scientific, Cordis, Getinge, Medtronic, and Terumo; G.W.S. (Maastricht UMC)—Cook Medical, Philips; S.L.Z. (University of Washington)—WL Gore; G.S.O. (University of Texas Health Science Center)—Cook Medical, WL Gore, GE healthcare, Centerline. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: This multicenter international study aimed to describe outcomes of fenestrated-branched endovascular aortic repairs (FB-EVAR) in a cohort of patients treated for chronic post-dissection thoracoabdominal aortic aneurysms (PD-TAAAs)., Methods: We reviewed the clinical data of all consecutive patients treated by FB-EVAR for repair of extent I to III PD-TAAAs in 16 centers from the United States and Europe (2008-2021). Data were extracted from institutional prospectively maintained databases and electronic patient records. All patients received off-the-shelf or patient-specific manufactured fenestrated-branched stent grafts. Endpoints were any cause mortality and major adverse events at 30 days, technical success, target artery (TA) patency, freedom from TA instability, minor (endovascular with <12 Fr sheath) and major (open or ≥12 Fr sheath) secondary interventions, patient survival, and freedom from aortic-related mortality (ARM)., Results: A total of 246 patients (76% male; median age, 67 years [interquartile range, 61-73 years]) were treated for extent I (7%), extent II (55%), and extent III (35%) PD-TAAAs by FB-EVAR. The median aneurysm diameter was 65 mm (interquartile range, 59-73 mm). Eighteen patients (7%) were octogenarians, 212 (86%) were American Society of Anesthesiologists class ≥3, and 21 (9%) presented with contained ruptured or symptomatic aneurysms. There were 917 renal-mesenteric vessels targeted by 581 fenestrations (63%) and 336 directional branches (37%), with a mean of 3.7 vessels per patient. Technical success was 96%. Mortality and rate of major adverse events at 30 days was 3% and 28%, including disabling complications such as new onset dialysis in 1%, major stroke in 1%, and permanent paraplegia in 2%. Mean follow-up was 24 months. Kaplan-Meier (KM) estimated patient survival at 3 and 5 years was 79% ± 6% and 65% ± 10%. KM estimated freedom from ARM was 95% ± 3% and 93% ± 5% at the same intervals. Unplanned secondary interventions were needed in 94 patients (38%), including minor procedures in 64 (25%) and major procedures in 30 (12%). There was one conversion to open surgical repair (<1%). KM estimated freedom from any secondary intervention was 44% ± 9% at 5 years. KM estimated primary and secondary TA patency were 93% ± 2% and 96% ± 1% at 5 years, respectively., Conclusions: FB-EVAR for chronic PD-TAAAs was associated with high technical success and a low rate of mortality (3%) and disabling complications at 30 days. Although the procedure is effective in the prevention of ARM, patient survival was low at 5 years (65%), likely due to the significant comorbidities in this cohort of patients. Freedom from secondary interventions at 5 years was 44%, although most procedures were minor. The significant rate of reinterventions highlights the need for continued patient surveillance., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: A significant proportion of patients with abdominal and thoracic aortic aneurysms (AA) do not proceed to intervention after reaching treatment threshold diameter due to a combination of poor cardiovascular reserve, frailty, and aortic morphology. This patient cohort has a high mortality; however, until this study, there exist no studies on the end-of-life care conservatively managed patients receive., Methods: This is a retrospective multicenter cohort study of 220 conservatively managed patients with AA referred to Leeds Vascular Institute (UK) and Maastricht University Medical Centre (the Netherlands) for intervention between 2017 and 2021. Demographic details, mortality, cause of death, advance care planning and palliative care outcomes were analysed to examine predictors of palliative care referral and efficacy of palliative care consultation., Results: A total of 1506 patients with AA were seen over this time period, giving a nonintervention rate of 15%. There was a 3-year mortality rate of 55%, a median survival of 364 days, and rupture was the reported cause of death in 18% of the decedents. Median follow-up was 34 months. Only 8% of all patients and 16% of decedents received a palliative care consultation, which took place a median of 3.5 days before death. Patients >81 years of age were more likely to have advance care planning. Only 5% and 23% of conservatively managed patients had documentation of preferred place of death and care priorities respectively. Patients with a palliative care consultation were more likely to have these services in place., Conclusions: Only a small proportion of conservatively treated patients had advance care planning and this was far below international guidelines on end-of-life care for adults, which recommends it for each of these patients. Pathways and guidance should be implemented to ensure patients not offered AA intervention receive end-of-life care and advance care planning., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Current management guidelines for ascending thoracic aortic aneurysms (aTAA) recommend intervention once ascending or sinus diameter reaches 5-5.5 cm or shows a growth rate of >0.5 cm/year estimated from echo/CT/MRI. However, many aTAA dissections (aTAAD) occur in vessels with diameters below the surgical intervention threshold of <55 mm. Moreover, during aTAA repair surgeons observe and experience considerable variations in tissue strength, thickness, and stiffness that appear not fully explained by patient risk factors. To improve the understanding of aTAA pathophysiology, we established a multi-disciplinary research infrastructure: The Maastricht acquisition platform for studying mechanisms of tissue-cell crosstalk (MAPEX). The explicit scientific focus of the platform is on the dynamic interactions between vascular smooth muscle cells and extracellular matrix (i.e., cell-matrix crosstalk), which play an essential role in aortic wall mechanical homeostasis. Accordingly, we consider pathophysiological influences of wall shear stress, wall stress, and smooth muscle cell phenotypic diversity and modulation. Co-registrations of hemodynamics and deep phenotyping at the histological and cell biology level are key innovations of our platform and are critical for understanding aneurysm formation and dissection at a fundamental level. The MAPEX platform enables the interpretation of the data in a well-defined clinical context and therefore has real potential for narrowing existing knowledge gaps. A better understanding of aortic mechanical homeostasis and its derangement may ultimately improve diagnostic and prognostic possibilities to identify and treat symptomatic and asymptomatic patients with existing and developing aneurysms.

Background: The impact of stent-graft complexity on clinical outcome after fenestrated endovascular aortic aneurysm repair (FEVAR) has been conflicting in the literature. The objective of this study was to compare mid-term results of stent-grafts with renal fenestrations alone with more complex stent-grafts including mesenteric fenestrations., Methods: A single center retrospective study was conducted on 154 patients, who underwent FEVAR from 2006 to 2020 at our institution., Results: There were 54 (35.1%) patients in the renal FEVAR group and 100 (64.9%) patients in the complex FEVAR group. Median follow-up of the total group was 25 months (IQR 7-45). There were no significant differences in technical success and perioperative mortality. Intraoperative complications (4% vs. 18%, P=0.001), operative time (145 min vs. 191 min, P=0.001), radiation dose (119372 mGy*cm 2 vs. 159573 mGy*cm 2 , P=0.004) and fluoroscopy time (39 min vs. 54 min, P=0.007) were significantly lower in the renal FEVAR group. During follow-up target vessel instability, endoleaks and reinterventions were not significantly different between the two groups., Conclusions: In this single center retrospective study, renal FEVAR was a safe and effective treatment for patients with juxtarenal AAA demonstrating fewer intraoperative complications and similar mid-term outcomes as complex FEVAR. If the anatomy is compatible for renal FEVAR, it might be unnecessary to expose patients to potentially more complications by choosing a complex FEVAR strategy.

Objective: The aim of this study was to compare outcomes of single or multistage approach during fenestrated-branched endovascular aortic repair (FB-EVAR) of extensive thoracoabdominal aortic aneurysms (TAAAs)., Methods: We reviewed the clinical data of consecutive patients treated by FB-EVAR for extent I to III TAAAs in 24 centers (2006-2021). All patients received a single brand manufactured patient-specific or off-the-shelf fenestrated-branched stent grafts. Staging strategies included proximal thoracic aortic repair, minimally invasive segmental artery coil embolization, temporary aneurysm sac perfusion and combinations of these techniques. Endpoints were analyzed for elective repair in patients who had a single- or multistage approach before and after propensity score adjustment for baseline differences, including the composite 30-day/in-hospital mortality and/or permanent paraplegia, major adverse event, patient survival, and freedom from aortic-related mortality., Results: A total of 1947 patients (65% male; mean age, 71 ± 8 years) underwent FB-EVAR of 155 extent I (10%), 729 extent II (46%), and 713 extent III TAAAs (44%). A single-stage approach was used in 939 patients (48%) and a multistage approach in 1008 patients (52%). A multistage approach was more frequently used in patients undergoing elective compared with non-elective repair (55% vs 35%; P < .001). Staging strategies were proximal thoracic aortic repair in 743 patients (74%), temporary aneurysm sac perfusion in 128 (13%), minimally invasive segmental artery coil embolization in 10 (1%), and combinations in 127 (12%). Among patients undergoing elective repair (n = 1597), the composite endpoint of 30-day/in-hospital mortality and/or permanent paraplegia rate occurred in 14% of single-stage and 6% of multistage approach patients (P < .001). After adjustment with a propensity score, multistage approach was associated with lower rates of 30-day/in-hospital mortality and/or permanent paraplegia (odds ratio, 0.466; 95% confidence interval, 0.271-0.801; P = .006) and higher patient survival at 1 year (86.9±1.3% vs 79.6±1.7%) and 3 years (72.7±2.1% vs 64.2±2.3%; adjusted hazard ratio, 0.714; 95% confidence interval, 0.528-0.966; P = .029), compared with a single stage approach., Conclusions: Staging elective FB-EVAR of extent I to III TAAAs was associated with decreased risk of mortality and/or permanent paraplegia at 30 days or within hospital stay, and with higher patient survival at 1 and 3 years., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Fiber Optic RealShape (FORS) technology has recently been introduced as an adjunctive guidance technology that allows real-time three-dimensional visualization of dedicated endovascular devices while avoiding radiation exposure. It consists of equipment which sends pulses of light through hair-thin optical fibers that run within a dedicated hydrophilic wire and selective catheters. The purpose of the study was to report the observed benefits and limitations related to the first edition of FORS technology., Methods: Data were collected prospectively from the first 50 patients undergoing FORS-guided endovascular repair at a single center between February 2020 and February 2021 as part of the global multicenter FORS Learn registry. All consecutive, elective procedures with one or more navigation tasks attempted with FORS were included. Factors related to FORS navigation task success were assessed. The time required for the catheterization of each task as well as the amount of radiation exposure (fluoroscopy time, dose area product, and estimated skin dose) were collected. A per-task analysis was conducted. End points included the success rate in achieving a stable FORS-guided catheterization, catheterization time, and radiation dose during catheterization., Results: During the study period from February 2020 to February 2021, 50 patients were treated using FORS technology. Forty-five patients were treated for aortic aneurysm, 4 for iliac artery aneurysm, and 1 for splenic artery aneurysm. Overall, 201 navigation tasks were completed for these procedures and FORS was used in 186 tasks (92.5%). No FORS-related complication was recorded and a success rate of 60.2% (n = 116) was observed. Target vessel (TV) angle of 45° or greater, TV stenosis, and the renal arteries as navigation tasks (compared with celiac artery or superior mesenteric artery) were associated with a lower success rate. Catheterization of a TV through a branch more frequently required a standard catheter in combination with the FORS-enabled guidewire. Successful task catheterization using FORS guidance was associated with a shorter catheterization time 6 minutes (interquartile range, 3-11 minutes) versus 16 minutes (interquartile range, 10-24 minutes) (P < .001) and lower radiation exposure compared with unsuccessful catheterization (dose area product, 4.4 cGy/cm 2 vs 12.5 cGy/cm 2 ; P < .001)., Conclusions: FORS technology was implemented successfully as a new guidance technology in a complex endovascular aortic repair program and was associated with an encouraging success rate and a high potential for radiation reduction., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this survey was to evaluate the daily clinical practice in European hospitals regarding the modalities to prevent spinal cord ischemia, with an emphasis on cerebrospinal fluid drainage (CSFD), in patients undergoing thoracic and thoracoabdominal endovascular repair., Design: A 21-item online survey on current practice of spinal cord protection with an emphasis on CSFD., Setting: Online service using Castor EDC software., Participants: Members of the European Association of Cardiothoracic Anaesthesiology and Intensive Care and European Society of Vascular Surgeons., Interventions: None., Measurements and Main Results: One hundred eighty invitations were sent and 104 were used for analysis. A majority of respondents used a written protocol for spinal cord protection during endovascular thoracic and thoracoabdominal repair (81/104 = 78%). The most common protective measures used were CSFD (79/81 = 98%), controlled hypertension (59/81 = 73%), drugs (11/81 = 14%), and hypothermia (6/81 = 7%). The two most common indications for placement of a spinal catheter were the length of the stent (83/104 = 80%) and location of aneurysm (71/104 = 68%). Preventive placement of the spinal drain (96/104) is the most common approach. In the subgroup of high-volume centers, 86% (12/14) of the respondents used a written protocol and all protocols include CSFD. Ninety-two percent (11/12) had included controlled arterial hypertension in the protocol compared with 70% (48/69) of the non-high-volume centers respondents., Conclusions: The majority of European centers use a written protocol that includes CSFD. This survey showed the similarities and differences in the management of CSFD in patients undergoing endovascular thoracic and thoracoabdominal repair., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To describe the outcome of open thoracoabdominal aortic aneurysm (TAAA) repair following previous aortic arch repair including elephant trunk (ET) or frozen elephant trunk (FET) for acute and chronic pathologies., Methods: This was a retrospective, observational, multicenter study including 32 patients treated between 2006 and 2019 in two aortic centers using identical surgical protocols. Assessment focused on perioperative and long-term outcome, namely in-hospital morbidity and mortality, as well as procedure-related reintervention rate and aortic-related mortality rate. Kaplan-Meier curves with 95% confidence intervals were used to analyze the overall survival after surgery within the cohort., Results: Thirty-two patients (mean age, 45.0 ± 13.6 years; 20 males [62.5%]) were treated because of acute (34.38% [n = 11]) or chronic (65.62% [n = 21]) aortic pathologies, including residual dissection following acute, symptomatic type A dissection (n = 7) and symptomatic mega aortic syndrome (n = 4), as well as post-dissection TAAA (n = 18) and asymptomatic mega aortic syndrome (n = 3). Twenty-eight patients (87.5%) received type II repair, and 4 patients (12.5%) received type III repair after previous ascending aorta and arch repair including ET/FET. Concomitant infrarenal and iliac vessel repair was performed in 38.7% (n = 12) and 29.4% (n = 10), respectively. The in-hospital mortality rate was 18.75% (n = 6). Spinal cord ischemia occurred in two cases, both after one-stage emergency procedure with one case of permanent paraplegia. Temporary acute kidney injury occurred in 41.94% (n = 13). The estimated 1-year survival rate was 78.1% (95% confidence interval, 63.9%-95.6%), with a median follow-up time of 1.29 years (interquartile range, 0.26-3.88 years). No procedure-related reinterventions and one case of aortic-related mortality, namely sepsis because of graft infection, was observed., Conclusions: Open TAAA repair following aortic arch repair including ET or FET because of acute or chronic aortic pathologies is associated with a relevant perioperative morbidity and mortality rate. During follow-up, a low aortic-related mortality rate and procedure-related reintervention rate were observed., (Copyright © 2021 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to evaluate the outcome of endovascular aortic arch repair for chronic dissection with a custom-made branched endograft., Background: Acute type A aortic dissections are often treated with prosthetic replacement of the ascending aorta. During follow-up, repair of an aneurysmal evolution of the false lumen distal to the ascending prosthesis can be a challenge both for the surgeon and the patient., Methods: We conducted a multicenter, retrospective study of consecutive patients from 14 vascular units treated with a custom-made, inner-branched device (Cook Medical, Bloomington, IN) for chronic aortic arch dissection. Rates of in-hospital mortality and stroke, technical success, early and late complications, reinterventions, and mortality during follow-up were evaluated., Results: Seventy consecutive patients were treated between 2011 and 2018. All patients were considered unfit for conventional surgery. In-hospital combined mortality and stroke rate was 4% (n = 3), including 1 minor stroke, 1 major stroke causing death, and 1 death following multiorgan failure. Technical success rate was 94.3%. Twelve (17.1%) patients required early reinterventions: 8 for vascular access complication, 2 for endoleak correction, and 2 for pericardial effusion drainage. Median follow-up was 301 (138-642) days. During follow-up, 20 (29%) patients underwent secondary interventions: 9 endoleak corrections, 1 open repair for prosthetic kink, and 10 distal extensions of the graft to the thoracic or thoracoabdominal aorta. Eight patients (11%) died during follow-up because of nonaortic-related cause in 7 cases., Conclusions: Endovascular treatment of aortic arch chronic dissections with a branched endograft is associated with low mortality and stroke rates but has a high reintervention rate. Further follow-up is required to confirm the benefits of this novel approach., Competing Interests: The authors report no conflicts of interest., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR)., Methods: This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests., Results: The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively)., Conclusion: In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair., (Copyright © 2020 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Aortic aneurysm is a vascular disease whereby the ECM (extracellular matrix) of a blood vessel degenerates, leading to dilation and eventually vessel wall rupture. Recently, it was shown that calcification of the vessel wall is involved in both the initiation and progression of aneurysms. Changes in aortic wall structure that lead to aneurysm formation and vascular calcification are actively mediated by vascular smooth muscle cells. Vascular smooth muscle cells in a healthy vessel wall are termed contractile as they maintain vascular tone and remain quiescent. However, in pathological conditions they can dedifferentiate into a synthetic phenotype, whereby they secrete extracellular vesicles, proliferate, and migrate to repair injury. This process is called phenotypic switching and is often the first step in vascular pathology. Additionally, healthy vascular smooth muscle cells synthesize VKDPs (vitamin K-dependent proteins), which are involved in inhibition of vascular calcification. The metabolism of these proteins is known to be disrupted in vascular pathologies. In this review, we summarize the current literature on vascular smooth muscle cell phenotypic switching and vascular calcification in relation to aneurysm. Moreover, we address the role of vitamin K and VKDPs that are involved in vascular calcification and aneurysm. Visual Overview- An online visual overview is available for this article.

Objective: This study compared the outcomes of open one stage with open two stage repair of type II thoraco-abdominal aortic aneurysms (TAAA)., Methods: This retrospective study included 94 patients (68 men) with a mean ± SD age of 54.5 ± 14 years who underwent open type II TAAA repair from March 2006 to January 2016. The mean aneurysm diameter was 65 ± 14.4 mm. The median follow up was 42 months (range 12-96). Seventy-six patients received one stage open repair and 18 patients were treated in two steps: 12 received two open procedures (thoracic and abdominal) and six received hybrid repair (one open and one endovascular procedure). This study focused on the comparison of open one stage and open two stage TAAA repair. The median time between the two steps was 31.5 days (range 1-169)., Results: In hospital mortality after open one stage repair versus open two stage type II repair was 22.4% versus 0% (odds ratio 7.352, 95% confidence interval [CI] 0.884-959.1]; p = .19). The one year survival rate after one stage repair versus open two stage repair was 74.7% (95% CI 62.7-83.3) versus 90.9% (95% CI 50.8-98.7 [p = .225]). The five year survival rate after one stage repair versus open two stage repair was 53.0% (95% CI 37.2-66.5) versus 90.9% (95% CI 50.8-98.7 [p = .141]). The hazard ratio for survival after one stage repair and after open two stage repair was 4.563 (95% CI 96.9-81.4 [p = .137]). Paraplegia was observed after open one stage repair versus open two stage in 10.5% vs. 8% (p = 1). Acute kidney injury requiring permanent dialysis and myocardial infarction were assessed for after open one stage repair and open two stage and were seen in 3.9% vs. 0% (p = 1) and in 5.3% vs. 0% (p = 1), respectively., Conclusion: Open two stage repair may be recommended as a treatment option for type II TAAAs if anatomically feasible, as it has a lower mortality and similar complication rates to one stage repair., (Copyright © 2018. Published by Elsevier B.V.)

Background: Patients with Stanford type B aortic dissections (ADs) are at risk of long-term disease progression and late complications. The aim of this study was to evaluate the natural course and evolution of acute type B AD and intramural hematomas (IMHs) in patients who presented without complications during their initial hospital admission and who were treated with optimal medical management (MM)., Methods: Databases from 2 aortic centers in Europe and the United States were used to identify 136 patients with acute type B AD (n = 92) and acute type B IMH (n = 44) who presented without complications during their index admission and were treated with MM. Computed tomography angiography scans were available at onset (≤14 days) and during follow-up for those patients. Relevant data, including evidence of adverse events during follow-up (AE; defined according to current guidelines), were retrieved from medical records and by reviewing computed tomography scan images. Aortic diameters were measured with dedicated 3-dimensional software., Results: The 1-, 2-, and 5-year event-free survival rates of patients with type B AD were 84.3% (95% confidence interval [CI], 74.4-90.6), 75.4% (95% CI, 64.0-83.7), and 62.6% (95% CI, 68.9-73.6), respectively. Corresponding estimates for IMH were 76.5% (95% CI, 57.8-87.8), 76.5% (95% CI, 57.8-87.8), and 68.9% (95% CI, 45.2-83.9), respectively. In patients with type B AD, risk of an AE increased with aortic growth within the first 6 months after onset. A diameter increase of 5 mm in the first half year was associated with a relative risk for AE of 2.29 (95% CI, 1.70-3.09) compared with the median 6 months' growth of 2.4 mm. In approximately 60% of patients with IMH, the abnormality resolved within 12 months and in the patients with nonresolving IMH, risk of an adverse event was greatest in the first year after onset and remained stable thereafter., Conclusions: More than one third of patients with initially uncomplicated type B AD suffer an AE under MM within 5 years of initial diagnosis. In patients with nonresolving IMH, most adverse events are observed in the first year after onset. In patients with type B AD an early aortic growth is associated with a greater risk of AE., (Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Medical treatment of initially uncomplicated acute Stanford type-B aortic dissection is associated with a high rate of late adverse events. Identification of individuals who potentially benefit from preventive endografting is highly desirable., Methods and Results: The association of computed tomography imaging features with late adverse events was retrospectively assessed in 83 patients with acute uncomplicated Stanford type-B aortic dissection, followed over a median of 850 (interquartile range 247-1824) days. Adverse events were defined as fatal or nonfatal aortic rupture, rapid aortic growth (>10 mm/y), aneurysm formation (≥6 cm), organ or limb ischemia, or new uncontrollable hypertension or pain. Five significant predictors were identified using multivariable Cox regression analysis: connective tissue disease (hazard ratio [HR] 2.94, 95% confidence interval [CI]: 1.29-6.72; P =0.01), circumferential extent of false lumen in angular degrees (HR 1.03 per degree, 95% CI: 1.01-1.04, P =0.003), maximum aortic diameter (HR 1.10 per mm, 95% CI: 1.02-1.18, P =0.015), false lumen outflow (HR 0.999 per mL/min, 95% CI: 0.998-1.000; P =0.055), and number of intercostal arteries (HR 0.89 per n, 95% CI: 0.80-0.98; P =0.024). A prediction model was constructed to calculate patient specific risk at 1, 2, and 5 years and to stratify patients into high-, intermediate-, and low-risk groups. The model was internally validated by bootstrapping and showed good discriminatory ability with an optimism-corrected C statistic of 70.1%., Conclusions: Computed tomography imaging-based morphological features combined into a prediction model may be able to identify patients at high risk for late adverse events after an initially uncomplicated type-B aortic dissection., (© 2017 American Heart Association, Inc.)

Purpose: Knowledge of medical radiation exposure permits application of radiation protection principles. In our center, the first dedicated real-time, automated patient and staff dose monitoring system (DoseWise Portal, Philips Healthcare) was installed. Aim of this study was to obtain insight in the procedural and occupational doses., Materials and Methods: All interventional radiologists, vascular surgeons, and technicians wore personal dose meters (PDMs, DoseAware, Philips Healthcare). The dose monitoring system simultaneously registered for each procedure dose-related data as the dose area product (DAP) and effective staff dose (E) from PDMs. Use and type of shielding were recorded separately. All procedures were analyzed according to procedure type; these included among others cerebral interventions (n = 112), iliac and/or caval venous recanalization procedures (n = 68), endovascular aortic repair procedures (n = 63), biliary duct interventions (n = 58), and percutaneous gastrostomy procedure (n = 28)., Results: Median (±IQR) DAP doses ranged from 2.0 (0.8-3.1) (percutaneous gastrostomy) to 84 (53-147) Gy cm 2 (aortic repair procedures). Median (±IQR) first operator doses ranged from 1.6 (1.1-5.0) μSv to 33.4 (12.1-125.0) for these procedures, respectively. The relative exposure, determined as first operator dose normalized to procedural DAP, ranged from 1.9 in biliary interventions to 0.1 μSv/Gy cm 2 in cerebral interventions, indicating large variation in staff dose per unit DAP among the procedure types., Conclusion: Real-time dose monitoring was able to identify the types of interventions with either an absolute or relatively high staff dose, and may allow for specific optimization of radiation protection., Competing Interests: AM Sailer, L Vergoossen, M Das, MW de Haan, JE Wildberger, and Cecile Jeukens received an institutional research grant from Philips Healthcare. L Paulis, AO Kovac, G Wijnhoven, GWH Schurink, and B Mees declares that they have no conflicts of interest. Informed Consent This study was approved by the local ethical committee. Written informed consent was obtained from all employees included in this study. Informed consent was obtained from all patients included in the study; written informed consent was waived.

Objectives: To analyse predictors for short- and long-term renal function changes after fenestrated and branched endovascular aortic repair (EVAR)., Methods: A total of 157 patients underwent fenestrated and branched EVAR. Procedural intra-arterial iodinated contrast volume was documented. Serum creatinine and estimated glomerular filtration rate (eGFR) at baseline, during 48 h following EVAR, at discharge and latest moment of follow-up were recorded. Development of post-EVAR acute kidney injury (AKI; according to AKIN criteria), and potential risk factors for renal failure were recorded. Multivariate regression analyses were used to identify independent risk factors for AKI and eGFR decrease during follow-up., Results: Forty-three patients (28 %) developed post-EVAR AKI. Long procedure time and occlusion of accessory renal arteries were independent risk factors for development of AKI. (odds ratio (OR) 1.005 per minute, 95 % CI 1.001-1.01; p = 0.025 and OR 3.02, 95 % CI 1.19-8.16; p = 0.029). Post-EVAR AKI was associated with a significantly increased risk for eGFR decrease at discharge and latest follow-up (hazard ratio (HR) 3.47, 95 % CI 1.63-7.36, p = 0.001 and HR 3.01, 95 % CI 1.56-5.80; p = 0.001). Iodinated contrast volume was not an independent risk factor for AKI or eGFR decrease during follow-up., Conclusion: Development of post-EVAR AKI is an independent risk factor for long-term renal function decrease., Key Points: • Longer procedure time is associated with an increased risk for AKI. • Renal perfusion defects on angiography are associated with increased risk for AKI. • Post-EVAR AKI is associated with higher probability for long-term eGFR decrease. • Iodinated contrast volume is not an independent risk factor for AKI. • Iodinated contrast volume is not an independent risk factor for long-term eGFR decrease.

Background: Endovascular interventions often are the preferred treatment in peripheral arterial disease for both intermittent claudication and chronic critical limb ischemia. Ever more advanced and anatomically complex procedures are being performed, which may increase the radiation exposure of patients and medical staff. We sought to determine the radiation exposure sustained in contemporary interventional radiology practice., Methods: A single-center observational cohort study of patients undergoing endovascular interventions for symptomatic peripheral arterial disease between January 1st, 2011 and July 31st, 2013 was performed. Radiation dose area product (DAP), peak skin dose (PSD), fluoroscopy time, and volume of contrast media were either measured or calculated and stratified according to patient demographics and anatomic location., Results: In 951 patients, who were treated with endovascular interventions, mean DAP was 108 ± 88 Gy × cm(2) and mean fluoroscopy time was 13 ± 12 min. DAP was significantly higher for aortoiliac procedures (142 ± 103 Gy × cm(2)) compared with femoral (58 ± 73 Gy × cm(2)), below-knee (45 ± 51 Gy × cm(2)) and multilevel (83 ± 90 Gy × cm(2)) procedures (P < 0.001 for all comparisons). PSD was significantly higher for aortoiliac procedures (0.99 ± 0.54 Gy) compared with femoral (0.55 ± 0.55 Gy), below-knee (0.48 ± 0.27 Gy), and multilevel (0.68 ± 0.47 Gy) procedures (P < 0.001 for all comparisons). In contrast, mean fluoroscopy time in aortoiliac interventions was significantly shorter (10 ± 15 min) compared with femoral (15 ± 12 min), below-knee (19 ± 10 min), and multilevel (23 ± 14 min) procedures (P < 0.001 for all comparisons)., Conclusions: Endovascular interventions in patients with symptomatic peripheral arterial disease involve a substantial radiation dose. Although fluoroscopy time is shorter, aortoiliac interventions result in greater radiation exposure than femoropopliteal or infrapopliteal interventions., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Aortic infections and aortic graft infections are one of the most dreadful clinical entities that a vascular surgeon can face. Clinical presentation of the patient can vary greatly and diagnosis can be difficult to make. In this manuscript, diagnostic modalities are reviewed and a diagnostic algorithm suggested. Further, results of present treatment options are evaluated and treatment strategies for different clinical scenarios suggested.

Purpose: Ionizing radiation and iodinated contrast media are potential drawbacks to repetitive follow-up CT angiography in current practice. The aim of the present study was to optimize radiation dose and contrast agent volume by using individualized CT angiography protocols., Materials and Methods: Eighty consecutive patients referred for CT angiography of the whole aorta were prospectively evaluated. Patients were divided into groups of patients with a body mass index (BMI) < 28 kg/m(2) (group 1; n = 50) and those with a BMI ≥ 28 kg/m(2) (group 2; n = 30). A control group consisted of 50 consecutive patients who were retrospectively evaluated. CT angiography parameters on a second-generation dual-source scanner were 128 × 0.6-mm collimation, pitch of 0.9, rotation time of 0.33 seconds, tube voltages of 80/100/120 kVp (group 1/group 2/control), reference tube current of 400 mA, and image reconstruction at 1-mm/0.8-mm slice thickness (kernels, B30f [control] and I30f/strength 3 [groups 1/2]). The control group received 120 mL of contrast agent (300 mgI/mL) at 4.8 mL/s; groups 1 and 2 received 44 mL and 53 mL at 3.3 mL/s and 4 mL/s, respectively. Effective dose was evaluated for each patient. Image quality was determined by qualitative image analysis at the levels of the thoracic, abdominal, and pelvic aorta as nondiagnostic, diagnostic, good, or excellent, and quantitative image analysis was performed, including attenuation values and contrast-to-noise ratio (CNR)., Results: Mean effective radiation dose values for CT angiography of the aorta were 3.7 mSv ± 0.7 in group 1, 6.7 mSv ± 1.4 in group 2, and 8.7 mSv ± 1.9 in the control group (P < .001). Mean attenuation values and CNR levels were 334 HU ± 66 and 16 ± 8, respectively, in group 1, 277 HU ± 56 and 14 ± 5 in group 2, and 305 HU ± 77 and 11 ± 4 in the control group., Conclusions: Iterative reconstruction algorithms resulted in 23%-57% less radiation in combination with 55%-63% less contrast agent volume compared with standard CT protocols., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Endovascular aneurysm repair (EVAR) has become the primary treatment option for elective abdominal aortic aneurysms. However, a significant number of patients require secondary interventions to maintain adequate aneurysm exclusion and ultimately prevent death from abdominal aortic aneurysm (AAA) rupture. To maintain success and offer timely secondary intervention, intensive image surveillance has been recommended. These rigorous surveillance regimens are costly and may have deleterious effects from radiation and contrast exposure. Improvements in patient selection, operative technique and devices have caused a decline in complications after EVAR. Therefore, there is a need to reduce surveillance after EVAR for patients at lower risk of complications and install individualized follow-up protocols. This review describes the current strategies for surveillance and clarification of risk factors and predictors for late complications and discusses proposed risk-adapted strategies for postoperative surveillance after EVAR.

Objective/background: Administration of iodinated contrast media during endovascular procedures for peripheral arterial disease (PAD) may cause contrast induced nephropathy (CIN). The aim of the present study was to establish the incidence of CIN after these procedures and to study its association with long-term loss of kidney function, cardiovascular events, and death., Methods: Consecutive patients first presenting with symptomatic PAD (Rutherford classification II-VI) who were treated with an endovascular procedure were included in this prospective observational cohort study. CIN was defined as >25% increase of serum creatinine concentration from baseline at 5 days after the intervention., Results: Some 337 patients were included with a mean estimated glomerular filtration rate (eGFR) of 67 mL/minute. Thirteen percent (95% confidence interval [CI] 9-16) of these patients developed CIN after endovascular interventions for PAD. One year after treatment, eGFR was reduced by 12.4 mL/minute (95% CI 8.6-16.2) in patients with CIN compared with 6.2 mL/minute (95% CI 4.9-7.0) in patients without acute kidney injury (p < .01). After correction for potential confounders, CIN was associated with a 7.8 mL/minute (95% CI 4.5-11.0) reduction of eGFR at 1 year after endovascular intervention (p < .01). Furthermore, patients with CIN were at increased risk of long-term cardiovascular events and mortality., Conclusion: Exposure to iodinated contrast media during endovascular procedures for symptomatic PAD frequently results in CIN. Patients with CIN are at increased risk of long-term loss of renal function, cardiovascular events, and death., (Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Autologous arteriovenous (AV) fistulas are the first choice for vascular access but have a high risk of non-maturation due to insufficient vessel adaptation, a process dependent on nitric oxide (NO)-signaling. Chronic kidney disease (CKD) is associated with oxidative stress that can disturb NO-signaling. Here, we evaluated the influence of CKD on AV fistula maturation and NO-signaling., Methods: CKD was established in rats by a 5/6th nephrectomy and after 6 weeks, an AV fistula was created between the carotid artery and jugular vein, which was followed up at 3 weeks with ultrasound and flow assessments. Vessel wall histology was assessed afterwards and vasoreactivity of carotid arteries was studied in a wire myograph. The soluble guanylate cyclase (sGC) activator BAY 60-2770 was administered daily to CKD animals for 3 weeks to enhance fistula maturation., Results: CKD animals showed lower flow rates, smaller fistula diameters and increased oxidative stress levels in the vessel wall. Endothelium-dependent relaxation was comparable but vasorelaxation after sodium nitroprusside was diminished in CKD vessels, indicating NO resistance of the NO-receptor sGC. This was confirmed by stimulation with BAY 60-2770 resulting in increased vasorelaxation in CKD vessels. Oral administration of BAY 60-2770 to CKD animals induced larger fistula diameters, however; flow was not significantly different from vehicle-treated CKD animals., Conclusions: CKD induces oxidative stress resulting in NO resistance that can hamper AV fistula maturation. sGC activators like BAY 60-2770 could offer therapeutic potential to increase AV fistula maturation.

Purpose: To assess and quantify the magnitude and direction of respiratory movement of the aorta and origins of its side branches., Methods: A quantitative 3-dimensional (3D) subtraction analysis of computed tomography (CT) scans during inspiration and expiration was performed to determine the respiratory geometric movements of the aorta and side branches in 60 patients. During breath-hold expiration and inspiration, 1-mm-thick CT slices of the aorta were acquired in unenhanced and contrast-enhanced scans. The datasets were compared using dedicated multiplanar reformation image subtraction software to determine the change in position of relevant anatomic sections, including the ascending thoracic aorta (AA), the origins of the brachiocephalic artery (BA) and left subclavian artery (LSA), the descending thoracic aorta (DTA) at the level of the tenth thoracic vertebra, as well as the origins of the celiac trunk, superior mesenteric artery, and the renal arteries., Results: Complex movement was visible during inspiration; the regions of interest in the thoracic aorta and side branches moved in the anterior, medial, and caudal directions compared with the expiration state. Mean 3D movement vectors (± standard deviation) were 8.9±3.6 mm (AA), 12.0±4.1 mm (BA), 11.1±3.9 mm (LSA), and 4.9±2.5 mm (DTA). Abdominal side branches moved in the caudal direction 1.3±1.1 mm. There was significantly less movement in the DTA compared to AA (p<0.001). The correlation coefficient between the extent of LSA movement and thoracic excursion was 0.78., Conclusion: The aorta and side branches undergo considerable respiratory movement. The results from this study provide an important contribution to understanding aortic dynamics., (© The Author(s) 2015.)

Purpose: The aim of the study was to evaluate the radiation exposure to operating room personnel and to assess determinants for high personal doses during endovascular aortic repair., Materials and Methods: Occupational radiation exposure was prospectively evaluated during 22 infra-renal aortic repair procedures (EVAR), 11 thoracic aortic repair procedures (TEVAR), and 11 fenestrated or branched aortic repair procedures (FEVAR). Real-time over-lead dosimeters attached to the left breast pocket measured personal doses for the first operators (FO) and second operators (SO), radiology technicians (RT), scrub nurses (SN), anesthesiologists (AN), and non-sterile nurses (NSN). Besides protective apron and thyroid collar, no additional radiation shielding was used. Procedural dose area product (DAP), iodinated contrast volume, fluoroscopy time, patient's body weight, and C-arm angulation were documented., Results: Average procedural FO dose was significantly higher during FEVAR (0.34 ± 0.28 mSv) compared to EVAR (0.11 ± 0.21 mSv) and TEVAR (0.06 ± 0.05 mSv; p = 0.003). Average personnel doses were 0.17 ± 0.21 mSv (FO), 0.042 ± 0.045 mSv (SO), 0.019 ± 0.042 mSv (RT), 0.017 ± 0.031 mSv (SN), 0.006 ± 0.007 mSv (AN), and 0.004 ± 0.009 mSv (NSN). SO and AN doses were strongly correlated with FO dose (p = 0.003 and p < 0.001). There was a significant correlation between FO dose and procedural DAP (R = 0.69, p < 0.001), iodinated contrast volume (R = 0.67, p < 0.001) and left-anterior C-arm projections >60° (p = 0.02), and a weak correlation with fluoroscopy time (R = 0.40, p = 0.049)., Conclusion: Average FO dose was a factor four higher than SO dose. Predictors for high personal doses are procedural DAP, iodinated contrast volume, and left-anterior C-arm projections greater than 60°.

Objective: Abdominal aortic aneurysms (AAAs) are local dilations that can lead to a fatal hemorrhage when ruptured. Wall stress analysis of AAAs is a novel tool that has proven high potential to improve risk stratification. Currently, wall stress analysis of AAAs is based on computed tomography (CT) and magnetic resonance imaging; however, three-dimensional (3D) ultrasound (US) has great advantages over CT and magnetic resonance imaging in terms of costs, speed, and lack of radiation. In this study, the feasibility of 3D US as input for wall stress analysis is investigated. Second, 3D US-based wall stress analysis was compared with CT-based results., Methods: The 3D US and CT data were acquired in 12 patients (diameter, 35-90 mm). US data were segmented manually and compared with automatically acquired CT geometries by calculating the similarity index and Hausdorff distance. Wall stresses were simulated at P = 140 mm Hg and compared between both modalities., Results: The similarity index of US vs CT was 0.75 to 0.91 (n = 12), with a median Hausdorff distance ranging from 4.8 to 13.9 mm, with the higher values found at the proximal and distal sides of the AAA. Wall stresses were in accordance with literature, and a good agreement was found between US- and CT-based median stresses and interquartile stresses, which was confirmed by Bland-Altman and regression analysis (n = 8). Wall stresses based on US were typically higher (+23%), caused by geometric irregularities due to the registration of several 3D volumes and manual segmentation. In future work, an automated US registration and segmentation approach is the essential point of improvement before pursuing large-scale patient studies., Conclusions: This study is a first step toward US-based wall stress analysis, which would be the modality of choice to monitor wall stress development over time because no ionizing radiation and contrast material are involved., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Primary endothelial cells (ECs) are the preferred cellular source for luminal seeding of tissue-engineered (TE) vascular grafts. Research into the potential of ECs for vascular TE has focused particularly on venous rather than arterial ECs. In this study we evaluated the functional characteristics of arterial and venous ECs, relevant for vascular TE. Porcine ECs were isolated from femoral artery (PFAECs) and vein (PFVECs). The proliferation rate was comparable for both EC sources, whereas migration, determined through a wound-healing assay, was less profound for PFVECs. EC adhesion was lower for PFVECs on collagen I, measured after 10 min of arterial shear stress. Gene expression was analysed by qRT-PCR for ECs cultured under static conditions and after exposure to arterial shear stress and revealed differences in gene expression, with lower expression of EphrinB2 and VCAM-1 and higher levels of vWF and COUP-TFII in PFVECs than in PFAECs. PFVECs exhibited diminished platelet adhesion under flow and cell-based thrombin generation was delayed for PFVECs, indicating diminished tissue factor (TF) activity. After stimulation, prostacyclin secretion, but not nitric oxide (NO), was lower in PFVECs. Our data support the use of venous ECs for TE because of their beneficial antithrombogenic profile., (Copyright © 2012 John Wiley & Sons, Ltd.)

Proximal infrarenal neck anatomy is a crucial factor in determining outcome of abdominal aortic aneurysm (AAA) repair. Unfavorable or demanding infrarenal neck anatomy significantly increases the complexity of both standard endovascular and open repair resulting in increased rates of morbidity and mortality. While technological improvements and expanding institutional experience have resulted in an increased proportion of patients with an AAA with unfavorable infrarenal neck treated by (fenestrated) endovascular techniques, open repair has also remained a valid technique. The purpose of this manuscript was to describe the wide array of endovascular and open techniques in use to treat patients with an AAA with a demanding infrarenal neck and discuss their results and indications.

Spinal cord ischemia (SCI) after thoracic and thoracoabdominal aortic aneurysm repair is a devastating complication, which happens after both open and endovascular repair. Incidence of SCI varies widely in the literature. Many factors during preoperative, operative and postoperative phases influence this incidence. The purpose of this article was to provide an overview on all factors influencing SCI and to report on the evidence in the literature about how to prevent SCI.

Purpose: This study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA)., Methods: Fusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography., Results: Average time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation)., Conclusions: Fluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.

Purpose: To evaluate patients radiation exposure of abdominal C-arm cone beam computed tomography (CBCT)., Methods: This prospective study was approved by the institutional review board; written, informed consent was waived. Radiation exposure of abdominal CBCT was evaluated in 40 patients who underwent CBCT during endovascular interventions. Dose area product (DAP) of CBCT was documented and effective dose (ED) was estimated based on organ doses using dedicated Monte Carlo simulation software with consideration of X-ray field location and patients' individual body weight and height. Weight-dependent ED per DAP conversion factors were calculated. CBCT radiation dose was compared to radiation dose of procedural fluoroscopy. CBCT dose-related risk for cancer was assessed., Results: Mean ED of abdominal CBCT was 4.3 mSv (95 % confidence interval [CI] 3.9; 4.8 mSv, range 1.1-7.4 mSv). ED was significantly higher in the upper than in the lower abdomen (p = 0.003) and increased with patients' weight (r = 0.55, slope = 0.045 mSv/kg, p < 0.001). Radiation exposure of CBCT corresponded to the radiation exposure of on average 7.2 fluoroscopy minutes (95 % CI 5.5; 8.8 min) in the same region of interest. Lifetime risk of exposure related cancer death was 0.033 % or less depending on age and weight., Conclusions: Mean ED of abdominal CBCT was 4.3 mSv depending on X-ray field location and body weight.

Objectives: A layer of intraluminal thrombus is commonly observed in abdominal aortic aneurysms (AAAs). The purpose of this study was to investigate whether AAAs with high thrombus signal intensity (SI) at T1-weighted (T1w) magnetic resonance imaging (MRI) exhibit a faster aneurysm growth rate., Methods: This was a prospective follow-up study. Patients with a small AAA underwent MRI examinations at 6 month intervals. Aneurysm thrombus and psoas muscle SI at the point of maximal diameter on T1w images were measured and expressed as a ratio (thrombus SI/muscle SI). Based on these measurements, patients were categorized into three groups: AAA with relative thrombus SI above (group A) and below (group B) the mean relative thrombus SI of 1.20. Patients with AAA without thrombus constituted group C. Eight patients were scanned twice within 2 weeks to investigate scan-rescan reproducibility. Aneurysm growth rates were expressed as the change in maximal cross sectional area (cm(2))., Results: A total of 35 patients (m/f: 26/9; age 72 ± 7 years; AAA maximal diameter 4.9 ± 0.5 cm) were included. Mean aneurysm growth rate for patients in group A (n = 11, 1.87 cm(2)/0.5 year) was two-fold higher than group B (n = 17, 0.78 cm(2)/0.5 year, p = .005) and eight-fold higher than group C (n = 7, 0.23 cm(2)/0.5 years, p = .004) at 6 months' follow-up. At 12 months' follow-up, the mean aneurysm growth rate remained significantly higher in group A (n = 7, 3.03 cm(2)/year) than groups B (n = 10, 1.63 cm(2)/year, p = .03) and C (n = 7, 0.73 cm(2)/year, p = .004). The reproducibility for thrombus SI measurements was found to be high with a coefficient of variation of 6.2%. Aneurysm maximal cross-sectional area at baseline was not significantly different for the three groups., Conclusions: Abdominal aortic aneurysms with high thrombus SI on T1w MR images are associated with higher aneurysm growth rates., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Despite medical treatment, one third of patients with uncomplicated type B aortic dissections experience severe late complications. The aim of this study was to identify patients at high risk of mortality during follow-up., Methods: A total of 183 patients with acute Stanford type B dissection were treated in one of the university hospitals (Aachen [Germany], Maastricht [The Netherlands], and Innsbruck [Austria]) between 1997 and 2010. Records indicated that 120 patients were treated conservatively. Of these patients, 16 were lost to follow-up. The maximum diameter, extent of the dissection, and patency of the side branches were determined from computed tomography angiography data. Survival and treatment failure were analyzed by univariate and multivariate Cox regression analysis. The univariate analysis investigated the influence of aortic diameter (≥41 vs <41 mm) on survival, and the multivariate analysis investigated the influence of aortic diameter, age, sex, and surgery on survival., Results: During the follow-up period, the initial treatment was converted to surgical treatment in 21 patients (20.2%). Sixteen of the 104 patients (15.4%) died after a mean of 845.5±805.9 days. The mean maximum aortic transversal diameter at admission was 41.2±8.7 mm. The multivariate analysis identified aortic diameter (P=.004; hazard ratio, 1.07) and age (P=.038; hazard ratio, 1.05) as risk factors that significantly reduce survival., Conclusions: Our study revealed both early aortic dilatation and older age as risk factors for increased mortality after conservative treatment of type B dissection., (Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study is to present experience with 10 patients with symptomatic aberrant subclavian artery (ASA) and aneurysm of ASA who underwent surgical treatment., Methods: From 2008 to 2011 10 patients with symptomatic aberrant subclavian artery (mean age 60 years [range 24-90 years]) were studied. Symptoms were dysphagia (n = 7), dyspnea (n = 4), acute chest pain (n = 1), respiratory distress syndrome (n = 1), superior cava syndrome, and shock (n = 1). Six patients had aneurysm formation of the ASA (mean diameter of 7.1 cm [range 3.0-12.4 cm]; rupture [n = 1], dissection [n = 1]). All data were analyzed retrospectively., Results: Treatment was performed as a hybrid procedure in eight patients. This included thoracic endoluminal graft exclusion with revascularization of the ASA, a pure endovascular procedure with two occluders in one patient, and an open procedure in one patient with ligation of the aberrant artery through a thoracotomy. Three patients died during the early postoperative period owing to pulmonary complications. All three suffered from a symptomatic aneurysm, and two were treated as an emergency procedure. Median follow-up was 20 months (range 12-49 months)., Conclusion: A symptomatic ASA and its associated aneurysmal formation should be excluded after diagnosis. In most cases, a hybrid procedure consisting of thoracic endografting and revascularization of the ASA is feasible., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: In the past decennium, the management of short-neck infrarenal and juxtarenal aortic aneurysms with fenestrated endovascular aneurysm repair (FEVAR) has been shown to be successful, with good early and midterm results. Recently, a new fenestrated device, the fenestrated Anaconda (Vascutek, Renfrewshire, Scotland), was introduced. The aim of this study was to present the current Dutch experience with this device., Methods: A prospectively held database of patients treated with the fenestrated Anaconda endograft was analyzed. Decision to treat was based on current international guidelines. Indications for FEVAR included an abdominal aortic aneurysm (AAA) with unsuitable neck anatomy for EVAR. Planning was performed on computed tomography angiography images using a three-dimensional workstation., Results: Between May 2011 and September 2013, 25 patients were treated in eight institutions for juxtarenal (n = 23) and short-neck AAA (n = 2). Median AAA size was 61 mm (59-68.5 mm). All procedures except one were performed with bifurcated devices. A total of 56 fenestrations were incorporated, and 53 (94.6%) were successfully cannulated and stented. One patient died of bowel ischemia caused by occlusion of the superior mesenteric artery. On completion angiography, three type I endoleaks and seven type II endoleaks were observed. At 1 month of follow-up, all endoleaks had spontaneously resolved. Median follow-up was 11 months (range, 1-29 months). There were no aneurysm ruptures or aneurysm-related deaths and no reinterventions to date. Primary patency at 1 month of cannulated and stented target vessels was 96%., Conclusions: Initial and short-term results of FEVAR using the fenestrated Anaconda endograft are promising, with acceptable technical success and short-term complication rates. Growing experience and long-term results are needed to support these findings., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: To determine the best location to measure the arterial peak flow (APF) in patients with peripheral arterial disease in order to facilitate clinical standardization., Methods: Two hundred and fifty-nine patients with varying degrees of peripheral artery disease (PAD) and 48 patients without PAD were included. All patients underwent magnetic resonance phase-contrast imaging of the common femoral artery (CFA), superficial femoral artery (SFA), and popliteal artery (PA). APF values of patients with PAD were compared with patients with no PAD. The discriminative ability to identify PAD was evaluated by means of receiver-operator characteristic curves and the corresponding areas under the curve (AUC)., Results: Mean APF values in patients with PAD were reduced by 42%, 55% and 59% compared with non-PAD patients for the CFA, SFA, and PA, respectively (p < .01). The AUC's were 0.84, 0.92, and 0.93 for the CFA, SFA, and PA, respectively., Conclusion: The APF measured at the level of the PA shows the largest differences between patients with PAD and patients with no PAD and the best discriminative ability compared with the APF acquired in the CFA or SFA. The PA seems to be the most suitable level for standardized flow measurements in patients with PAD in order to obtain relevant functional information about the vascular status., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the feasibility and reproducibility of dynamic contrast-enhanced MRI (DCE-MRI) to quantify abdominal aortic aneurysm (AAA) vessel wall enhancement dynamics which may reflect the amount of wall microvasculature. AAA vessel wall microvasculature has been linked with aneurysm progression and rupture., Materials and Methods: Thirty patients with AAA underwent DCE-MRI at 1.5 Tesla. Enhancement dynamics of the aneurysm wall were quantified in regions-of-interest (ROIs) in the vessel wall by calculating the transfer constant (K(trans) ) using pharmacokinetic modeling and the area-under-gadolinium-curve (AUC). To assess reproducibility, 10 patients were imaged twice on different occasions. ROIs were drawn by two independent observers. The intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined to investigate intra-, interobserver, and interscan variability., Results: Twenty-eight analyzable MR examinations were included for pharmacokinetic analysis after excluding two examinations due to severe motion artifacts. Intra-, interobserver, and interscan variability for K(trans) were small (all ICC > 0.90, CV < 14%) as well as for AUC measurements (all ICC > 0.88, CV < 23%)., Conclusion: Quantitative analysis of AAA vessel wall enhancement dynamics with DCE-MRI is feasible and reproducible., (Copyright © 2013 Wiley Periodicals, Inc.)

Objectives: To evaluate the effect of intraoperative guidance by means of live fluoroscopy image fusion with computed tomography angiography (CTA) on iodinated contrast material volume, procedure time, and fluoroscopy time in endovascular thoraco-abdominal aortic repair., Methods: CTA with fluoroscopy image fusion road-mapping was prospectively evaluated in patients with complex aortic aneurysms who underwent fenestrated and/or branched endovascular repair (FEVAR/BEVAR). Total iodinated contrast material volume, overall procedure time, and fluoroscopy time were compared between the fusion group (n = 31) and case controls (n = 31). Reasons for potential fusion image inaccuracy were analyzed., Results: Fusion imaging was feasible in all patients. Fusion image road-mapping was used for navigation and positioning of the devices and catheter guidance during access to target vessels. Iodinated contrast material volume and procedure time were significantly lower in the fusion group than in case controls (159 mL [95% CI 132-186 mL] vs. 199 mL [95% CI 170-229 mL], p = .037 and 5.2 hours [95% CI 4.5-5.9 hours] vs. 6.3 hours (95% CI 5.4-7.2 hours), p = .022). No significant differences in fluoroscopy time were observed (p = .38). Respiration-related vessel displacement, vessel elongation, and displacement by stiff devices as well as patient movement were identified as reasons for fusion image inaccuracy., Conclusion: Image fusion guidance provides added value in complex endovascular interventions. The technology significantly reduces iodinated contrast material dose and procedure time., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Endovascular treatment of short neck infrarenal and juxtarenal abdominal aortic aneurysms (AAA) is feasible. Many different techniques have been used, including standard stent-grafts with or without adjuncts as endoanchors or chimney grafts, fenestrated stent-grafts or even newer concepts like the multilayer flow modulating stent. The purpose of this article was to describe the techniques, the indications and results of the various endovascular methods to treat short neck infrarenal and juxtarenal AAA.

Vascular tissue engineering relies on the combination of patient-derived cells and biomaterials to create new vessels. For clinical application, data regarding the function and behavior of patient-derived cells are needed. We investigated cell growth and functional characteristics of human venous endothelial cells (HVECs) from coronary arterial bypass graft (CABG), chronic kidney disease (CKD), and control patients. HVECs were isolated from venous specimens that were obtained during elective surgical procedures by means of collagenase digestion. Gene expression, proliferation, migration, secretory functions, and thrombogenic characteristics were evaluated using high-throughput assays. A total of 48 cell batches (14 control, 19 CABG, and 15 CKD subjects) were assessed. Proliferation, population doubling times, and migration of HVECs derived from CABG and CKD patients did not differ from controls. Thrombomodulin expression was higher in CABG-HVECs compared with controls. HVEC-induced thrombin formation in plasma did not differ between groups, and the contact activation pathway was the major contributor to coagulation. Patient-derived HVECs were able to attach and survive on polycaprolactone scaffolds that were coated with fibrin. HVECs from cardiovascular-diseased and CKD patients showed comparable functional characteristics with HVECs derived from uncompromised patients. We, therefore, conclude that endothelial cells from aged patients with comorbidities can be safely used for isolation and in vitro expansion for vascular tissue engineering.

Objectives: The purpose of this study was to compare the success rate of successful arterial peak flow (APF) and ankle-brachial index (ABI) measurements in patients with suspected or known peripheral arterial disease (PAD)., Materials and Methods: 183 patients with varying degrees of PAD were included. All subjects underwent ABI measurements and MR imaging of the popliteal artery to determine APF. Proportions of patients with successful APF and ABI measurements were compared and the discriminative capability was evaluated., Results: APF was successfully measured in 91% of the patients, whereas the ABI could be determined in 71% of the patients (p<0.01). Success rates of APF and ABI were significantly higher in patients with intermittent claudication (95% and 80%, respectively) than in patients with critical ischemia (87% and 62%, respectively)., Conclusions: Compared to the assessment of PAD severity with ABI, the success rate of MRI-based APF measurements in patients with a clinical indication for MRA is 20% higher, with similar discriminatory capacity for disease severity. Therefore, APF is an especially convenient and valuable measure to assess severity in PAD patients scheduled to undergo MR angiography to obtain additional functional information concerning the vascular status.