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Chronic limb-threatening ischemia (CLTI) carries a significant risk of limb loss and thus demands urgent attention. Calcified atherosclerotic disease affecting the infra-popliteal (IP) arteries poses a formidable challenge for effective revascularization due to the narrow vessel diameter and the common presence of extensively calcified, long occlusive lesions. Intravascular lithotripsy (IVL) is an endovascular treatment that induces microfractures in the medial calcifications of blood vessels, thereby facilitating the clearance of calcified obstructive arterial lesions. This review assesses the growing body of evidence from multiple prospective studies that have investigated the role of IVL in the treatment of peripheral arterial disease (PAD) involving the IP segment. The clinical efficacy of IVL has been extensively studied and validated in various trials and real-world experiences. These studies consistently demonstrate IVL's ability to achieve vessel preparation, with excellent procedural success rates and low rates of major adverse events. Moreover, IVL has shown remarkable versatility, proving effective across a wide spectrum of PAD, including iliac artery disease, femoropopliteal disease and IP calcified disease. The available results from existing literature are encouraging and demonstrates safety and efficacy of the technology in treating calcified PAD. Additional studies on a larger scale are needed to better understand its long-term effects.

Background: The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO)., Methods: A group of vascular surgeons from Australia and New Zealand with specific interest, training, and experience in the management of VOO were surveyed to assess current local practices. The results were analyzed and areas of disagreement identified. After this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely, the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. A selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified. The final recommendations were further reviewed and endorsed by another group of venous experts., Results: The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with clinically relevant VOO, a Clinical-Etiologic-Anatomic-Physiologic score of ≥3 or a Venous Clinical Severity Score for pain of ≥2, or both, including venous claudication, with evidence of >50% stenosis should be considered for venous stenting (Level of Recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should also be considered for venous stenting (Level of Recommendation Ic). Asymptomatic patients should not be offered venous stenting (Level of Recommendation IIIc). Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion of >50% has been uncovered, should be considered for venous stenting (Level of Recommendation Ib)., Conclusions: Patients with VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. International guidelines aimed at developing standards of care to avoid undertreating and overtreating patients are applicable to Australia and New Zealand practice and will serve as an educational platform for future developments., Competing Interests: Disclosures None., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Arteriovenous fistula (AVF) is the optimal form of vascular access for most haemodialysis dependant patients; however, it is prone to the formation of stenoses that compromise utility and longevity. Whilst there are many factors influencing the development of these stenoses, pathological flow-related phenomena may also incite the formation of intimal hyperplasia, and hence a stenosis. Repeated CFD-derived resistance was calculated for six patient who had a radiocephalic AVF, treated with an interwoven nitinol stent around the juxta-anastomotic region to address access dysfunction. A three-dimensional freehand ultrasound system was used to obtain patient-specific flow profiles and geometries, before performing CFD simulations to replicate the flow phenomena in the AVF, which enabled the calculation of CFD-derived resistance. We presented six patient cases who were examined before and after treatment and our results showed a 77% decrease in resistance, recorded after a surgical intervention to address access dysfunction. Problematic AVFs were found to have high resistance, particularly in the venous segment. AVFs with no reported clinical problems, and clinical patency, had low resistance in the venous segment. There did not appear to be any relationship with clinical problems/patency and resistance values in the arterial segment. Identifying changes in resistance along the circuit allowed stenoses to be identified, independent to that determined using standard sonographic criteria. Our exploratory study reveals thatCFD-derived resistance is a promising metric that allows for non-invasive identification of diseased AVFs. The pipeline analysis enabled regular surveillance of AVF to be studied to aid with surgical planning and outcome, further exhibiting its clinical utility., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The arteriovenous fistula (AVF) is commonly faced with stenosis at the juxta-anastomotic (JXA) region of the vein. Implantation of a flexible nitinol stent across the stenosed JXA has led to the retention of functioning AVFs leading to the resulting AVF geometry being distinctly altered, thereby affecting the haemodynamic environment within it. In this study, large eddy simulations of the flow field within a patient-specific AVF geometry before and after stent implantation were conducted to detail the change in flow features. Although the diseased AVF had much lower flow rates, adverse flow features, such as recirculation zones and swirling flow at the anastomosis, and jet flow at the stenosis site were present. Larger velocity fluctuations (leading to higher turbulent kinetic energy) stemming from these flow features were apparent in the diseased AVF compared to the stented AVF. The unsteadiness at the stenosis created large regions of wall shear stress (WSS) fluctuations downstream of the stenosis site that were not as apparent in the stented AVF geometry. The larger pressure drop across the diseased vein, compared to the stented vein, was primarily caused by the constriction at the stenosis, potentially causing the lower flow rate. Furthermore, the WSS fluctuations in the diseased AVF could lead to further disease progression downstream of the stenosis. The change in bulk flow unsteadiness, pressure drop, and WSS behaviour confirms that the haemodynamic environment of the diseased AVF has substantially improved following the flexible stent implantation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process., Competing Interests: Funding Support and Author Disclosures Dr Li has served on the advisory board for Boston Scientific, Inari Medical, and Medtronic; and as a consultant for Abbott Vascular, Endovascular Engineering, and Philips. Dr Varcoe has served as a consultant for Abbott Vascular, Intact Medical, Shockwave, Intervene, Surmodics, and Boston Scientific; and on the advisory board for Abbott Vascular and Intact Medical. Dr Manzi has served as a consultant for Abbott Vascular, Bard/BD, Boston Scientific, Angiodroid, Cook, and Terumo. Dr Kum has served as a consultant for Abbott Vascular, Boston Scientific, and LimFlow. Dr Iida has reported that he has no relationships relevant to the contents of this paper to disclose. Dr Schmidt has received consulting and speaker honoraria from Abbott Vascular, Boston Scientific, Bard/BD, Cook, Cordis, Intact Vascular, Medtronic, Reflow, and Upstream Peripheral. Dr Shishehbor has served on the global advisory board for Abbott Vascular, Medtronic, Terumo, Phillips, Boston Scientific, ANT, and Inquis Medical., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This review details the utility of intravascular ultrasound (IVUS) for the management of peripheral artery and venous disease. The purpose of this document is to provide an update in the use of IVUS in peripheral arterial and venous pathology and demonstrate the use of IVUS as a practical diagnostic imaging procedure to evaluate and treat peripheral vascular disorders. IVUS, a diagnostic tool that relies on sound waves to produce precise images of the vessel being evaluated, was originally introduced to the medical community for the purposes of peripheral artery imaging, though it was quickly adapted for coronary interventions with positive outcomes. The utility of IVUS includes vessel measurement, pre- and post-procedural planning, treatment optimisation, and detection of thrombus, dissection or calcium severity. While angiography remains the standard imaging approach during peripheral intervention, multiple observational studies and small prospective trials have shown that in comparison, IVUS provides more accurate imaging detail, which may improve procedural outcomes. IVUS can also address limitations of angiography, including the need to administer contrast medium and eliminate the ambiguity associated with other forms of imaging. This review provides contemporary examples of where IVUS is being used during peripheral intervention as well as representative imaging to serve as a resource for the practising clinician.

Aims: COVID-19 had a devastating impact on patients with severe aortic stenosis (AS). Like many cardiac procedures, transcatheter aortic valve replacement (TAVR) services were suspended during the first wave of COVID-19. We took the opportunity to evaluate the clinical outcomes and identify any delays at different stages of the TAVR pathway during the COVID-19 pandemic., Methods: Prospectively collected data on 210 consecutive TAVR patients between March 2019 and March 2021 were analysed. We compared the clinical outcomes and 30-day mortality rates of TAVR cases pre-pandemic and during the pandemic. We also looked to identify any time lags from the initial referral to respective stages of the TAVR workup., Results: A total of 134 patients underwent TAVR prior to the national lockdown (March 2019-March 2020), compared to 76 patients during COVID-19 (April 2020-April 2021). Success rates of TAVR were similar (99% prior to the pandemic and 97.4% during COVID-19). The 30-day survival rates were 98.6% and 94.7%, respectively. Median length of stay post TAVR was 2 days during COVID-19 and 2.5 days prior to the pandemic (p = 0.064). Patients were seen quicker in clinic (median of 33 days) during COVID-19, compared to 51 days before COVID-19 (p = 0.044). No significant difference in times from referral to discussion at TAVR multidisciplinary team (MDT) meetings, CT Aortogram and TAVR implantation, in both groups., Conclusions: Reconfiguring the patient pathway during COVID-19 allowed TAVR to be performed safely, with a similar success rate and no excess complications or increased 30-day mortality. There proved to be no delay in the respective stages of patient TAVR workup, during the pandemic., Competing Interests: Conflicts of interest None declared., (Copyright © 2022 Hellenic Society of Cardiology. All rights reserved.)

Background: There has been growing use of intravascular ultrasound (IVUS) during lower extremity arterial and venous revascularization. Observational data suggest that the use of IVUS can improve periprocedural and long-term outcomes, but largescale prospective data remain limited. Consensus opinion regarding the appropriate use of IVUS during peripheral intervention is needed., Objectives: The purpose of this consensus document is to provide guidance on the appropriate use of IVUS in various phases of peripheral arterial and venous interventions., Methods: A 12-member writing committee was convened to derive consensus regarding the appropriate clinical scenarios for use of peripheral IVUS. The group iteratively created a 72-question survey representing 12 lower extremity arterial interventional scenarios. Separately, a 40-question survey representing 8 iliofemoral venous interventional scenarios was constructed. Clinical scenarios were categorized by interventional phases: preintervention, intraprocedure, and postintervention optimization. Thirty international vascular experts (15 for each survey) anonymously completed the survey instrument. Results were categorized by appropriateness using the median value and disseminated to the voting panel to reevaluate for any disagreement., Results: Consensus opinion concluded that IVUS use may be appropriate during the preintervention phase for evaluating the etiology of vessel occlusion and plaque morphology in the iliac and femoropopliteal arteries. IVUS was otherwise rated as appropriate during iliac and femoropopliteal revascularization in most other preintervention scenarios, as well as intraprocedural and postprocedural optimization phases. IVUS was rated appropriate in all interventional phases for the tibial arteries. For iliofemoral venous interventions, IVUS was rated as appropriate in all interventional phases., Conclusions: Expert consensus can help define clinical procedural scenarios in which peripheral IVUS may have value during lower extremity arterial and venous intervention while additional prospective data are collected., Competing Interests: Funding Support and Author Disclosures Dr Secemsky is funded in part by National Institutes of Health/National Heart, Lung, and Blood Institute grant K23HL150290. This review was funded in part by unrestricted educational grants from Boston Scientific and Philips IGT. These companies have not seen or participated in the creation of this manuscript, including no contribution in the writing of the manuscript, significant edits, or the decision whether to submit. Dr Secemsky is a consultant and Speakers Bureau and/or advisory board member for Abbott, Bayer, Becton, Dickinson and Company, Boston Scientific, Cook, Cardiovascular Systems, Inc., Endovascular Engineering, Inari, Janssen, Medtronic, Philips, and VentureMed; has received grants to the institution from the National Institutes of Health/National Heart, Lung, and Blood Institute (K23HL150290), the U.S. Food and Drug Administration, Harvard Medical School (Shore Faculty Development Award), AstraZeneca, BD, Boston Scientific, Cook, Cardiovascular Systems, Inc., Laminate Medical, Medtronic, and Philips. Dr Kohi is a board member at VIVA Physicians; and is a global principal investigator of the ELEGANCE (Drug-Eluting Registry: Real-World Treatment of Lesions in the Peripheral Vasculature) registry with Boston Scientific but is not being personally compensated. Dr Rosenfield is a consultant and scientific advisory board member for Angiodynamics, Boston Scientific, Contego, InspireMD, Magneto, Mayo Clinic, Neptune Medical, Philips, Summa Therapeutics, Surmodics, Thrombolex, and Truvic; has received grants to the institution from the National Institutes of Health and Boston Scientific; holds equity in Accolade, Access Vascular, Althea Medical, Contego, Cruzar Systems, Embolitech, Endospan, JanaCare, Magneto, Orchestra, PQ Bypass, Shockwave, Thrombolex, Truvic, and Valcare; and is a board member for the National PERT Consortium, a not-for-profit 501(c)(3) organization dedicated to advancing treatment and improving outcomes in pulmonary embolism. Dr Lichtenberg has received honoraria for lectures from Cagent Vascular, CR Bard, Boston Scientific, AB Medica, Philips, Terumo, Biotronik, Veryan, and Medtronic; has received honoraria for advisory board activities from Cagent Vascular, Biotronik, Veryan, Boston Scientific, Philips, Soundbite, Limflow, Covellus, and Medtronic; has participated in clinical trials for Cagent Vascular, Biotronik, CR Bard, Verya, Boston Scientific, LimFlow, Terumo, and Philips; and has received research funding from Cagent Vascular, Biotronik, Boston Scientific, Veryan, plusMedica, Philips, and CR Bard. Dr Meissner has served as a consultant for Cook Medical for a project using a Delphi consensus panel for venous stenting; Dr Varcoe consults for Medtronic, Abbott, BD Bard, Philips Healthcare, Intervene, and Surmodics; Dr Holden is a medical advisory board member for Medtronic, Gore, and Boston Scientific; and is a clinical investigator for Bard/BD, Boston Scientific, Cagent Medical, Cook Medical, Endologix, Endospan, Gore Medical, Intact Vascular, Medtronic, Philips, Reflow Medical, Shockwave Medical, and TriReme Medical. Dr Jaff is a part-time employee at Boston Scientific; is a consultant at Glide Healthcare; and holds equity investments in R3 Vascular, Nectero, Vactronix, and EFemoral. Dr Chalyan is an employee at Philips IGT. Dr Clair discloses his involvement with Boston Scientific, Elastimed, Endologix, and Medtronic and clarifies that he does not receive any income from these relationships, as all the income goes to the organization by which he is employed; and serves as a data and safety monitoring board member for Bard/Becton, Dickinson and Company and Boston Scientific (all income goes to the medical group). Dr Hawkins is a consultant at Baim; and conducts institutional research at Behring, Hemostemix, and the National Institutes of Health/National Heart, Lung, and Blood Institute. Dr Parikh is an advisory board member for Abbott, Boston Scientific, Medtronic, Philips, and Cordis; has conducted research for Abbott, Boston Scientific (data and safety monitoring board), Shockwave, Surmodics, TriReme, Veryan Medical, Acotec, and MedAlliance; and is a consultant for Abiomed, Canon, Inari, Penumbra, and Terumo. Dr Mosarla has reported that she has no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The ACURATE neo™ is a novel, second-generation self-expanding supra-annular transcatheter heart valve (THV). The objective of this multi-centre registry is to assess the safety, clinical utility, and impact of 'learning-curve-experience' (LCE) on transcatheter aortic valve replacement outcomes in the United Kingdom (UK) and Ireland., Methods: We prospectively collected data from seven ACURATE neo™ THV implanting centres (n = 484) between February 2016 and November 2020. We compared mortality rates and outcomes in the LCE group (n = 120) compared to next successive 120 cases., Results: The mean age of the cohort was 81.9(SD: 6.1) years and the majority were in the moderate risk category (EuroSCORE-II):3.3(SD: 3). The 97.5% of cases were performed under local anesthetic. The valve was successfully deployed in 98.8% of cases. The survival rate at 30 days was 97.9%. The incidence of stroke was 2.5%. Life threatening bleeding occurred in 0.6% of cases and vascular access complications occurred in 21 (4.3%) patients. Implantation-related conduction abnormalities occurred in 8.3% but only 5.6% required a PPM. The successful valve deployment occurred in 96% of the patients in the LCE group compared to 100% in the other group (p = 0.04; OR-2[CI 1.7-2.3]). The mortality rates at 30 days (1.7% vs. 1.7%) and 1 year (1.9% vs. 2.7%) were comparable between the two groups., Conclusions: This study represents the largest published UK and Ireland real-world experience of the ACURATE neo™ valve. The procedural success rates and safety outcomes were excellent and endorse its utility in clinical practice. The LCE appears to have an impact on the successful valve deployment but without translating into short-term or long-term outcomes., (© 2021 Wiley Periodicals LLC.)

Introduction: Venous leg ulcers (VLU) embody the most severe stage of the broad spectrum of chronic venous disease. Approximately 40% of patients with VLU present with the underlying deep venous disease (DVD). Although the data are scarce, these deep venous disease-related VLU (DRV) are thought to have higher recurrence rates and a substantial economic burden. The objective of this study was to assess the economic burden of DRV across Australia, France, Germany, Italy, Spain, the UK, and the USA., Methods: A comprehensive literature review was undertaken to identify publications documenting the incidence and prevalence of VLU and DRV, medical resource utilization, and associated costs of DRV. Findings from this literature review were used to estimate the economic burden of illness, including direct medical costs over a 12-month interval following initial presentation of a newly formed DRV., Results: Total annual incidence of new or recurrent DRV in Australia, France, Germany, Italy, Spain, UK, and the US are estimated at 122,000, 263,000, 345,000, 253,000, 85,000, 230,000, and 643,000 events, respectively, in 2019. Incidence ranges from 0.73 to 3.12 per 1000 persons per year. The estimated annual direct medical costs for patients managed conservatively in these geographies total ~ $10.73 billion (USD) or $5527 per person per year., Conclusion: The availability of published data on the costs of VLU care varies widely across countries considered in this analysis. Although country-specific VLU practice patterns vary, there is a uniform pattern of high-cost care.

Postural orthostatic tachycardia syndrome (POTS) is a variant of cardiovascular autonomic disorder characterised by an excessive heart rate on standing and orthostatic intolerance. We present a rare case of a 38-year-old man who underwent open repair of a thoracoabdominal aortic aneurysm for a chronic Stanford type B aortic dissection whose recovery was complicated by POTS. He received blood transfusions and was commenced on metoprolol, fludrocortisone and ivabradine with significant improvement in his symptoms. Correct assessment of postoperative tachycardia including postural telemetry is the key to identifying this condition and its successful management., (Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2021.)

Arteriovenous fistula creation is the preferred vascular access for haemodialysis therapy, but has a large failure rate in the maturation period. This period generally lasts 6 to 8 weeks after surgical creation, in which the vein and artery undergo extensive vascular remodelling. In this review, we outline proposed mechanisms for both arteriovenous fistula maturation and arteriovenous fistula failure. Clinical, animal and computational studies have not yet shown a definitive link between any metric and disease development, although a number of theories based on wall shear stress metrics have been suggested. Recent work allowing patient-based longitudinal studies may hold the key to understanding arteriovenous fistula maturation processes.

Purpose: To assess the incidence and predictors of severe, persistent postprocedural hypotension (PPH) after carotid artery stenting (CAS). Materials and Methods: A total of 146 patients (mean age 72.8 years; 104 men) who underwent 160 CAS procedures using a standardized protocol at 3 vascular centers were retrospectively analyzed. The primary endpoint was postprocedural hypotension, defined as a reduction in systolic blood pressure (SBP) >40 mm Hg from baseline or an SBP of <90 mm Hg sustained for >1 hour after CAS. Potential prognostic factors for postprocedural hypotension were identified and subjected to logistic regression analyses; outcomes are presented as the odds ratios (ORs) with 95% confidence intervals (CIs). Results: PPH developed in 36 (24.7%) patients after 37 (23.1%) CAS procedures. These patients had significantly longer intensive care unit and hospital stays than those who did not develop hypotension (p<0.001). PPH was associated with severe lesion calcification (OR 6.28, 95% CI 1.81 to 21.98, p=0.004) and contrast volume (OR 1.02, 95% CI 1.01 to 1.02, p<0.001). A 4-fold increase in the risk of PPH (OR 4.22, 95% CI 1.38 to 13.33, p=0.012) was found between the embolic protection device most associated with PPH (Angioguard) and the device least associated with PPH (Emboshield NAV6). A similar trend was also observed for the Precise vs Xact stents (OR 6, 95% CI 2.08 to 17.6, p=0.001). Bootstrapped multivariable modeling identified the Precise stent and contrast volume as significant predictors of persistent postprocedural hypotension. Further investigation of the contrast volume revealed associations with sex, severe calcification, arch type, previous coronary artery bypass surgery, and primary stenting, suggesting that the contrast volume reflects the complexity of the procedure. Conclusion: The complexity of the procedure and type of stent may play a role in the development of postprocedural hypotension after CAS.

Background: The superiority of drug eluting stents versus bare metal stents or balloon angioplasty in the treatment of patients with critical limb ischemia and infrapopliteal lesions has been established. However, only shorter lesions were evaluated. This study was designed to evaluate the immediate and long-term (up to 12 months) outcome of the Xience Prime™ Everolimus-Eluting Coronary Stent System (Abbott Vascular) in a controlled, prospective, multi-center investigation for long lesions up to 10 cm., Methods: All patients with critical limb ischemia and long infrapopliteal lesions between 30 and 100 mm, who met the inclusion criteria, were included in this study. The primary endpoint was primary patency at 12 months, defined as absence of restenosis (≥50% stenosis) or occlusion based on quantitative analysis of contrast angiography., Results: Between August 2011 and October 2013, 60 patients were enrolled in this study with a mean lesion length of 47.40±25.06 mm (range 2-100 mm). The primary patency rate at 12 months was 75.4%. Freedom from target lesion revascularization was 84.9%. The amputation rate was rare (94.4% freedom from amputation). At the 12-month follow-up time point, a total of 36 out of 42 (85.7%) patients improved in their Rutherford classification by at least 1 class., Conclusions: The use of everolimus-eluting stents in longer infrapopliteal lesions in the treatment of critical limb ischemia is safe and effective with a comparable primary patency, freedom from target lesion revascularization and amputation free survival as in short lesions.

Objectives: This study sought to compare the local tissue response and subsequent volume of intimal hyperplasia (IH) that develops throughout the maturation of an arteriovenous fistula created using continuous/interrupted polypropylene with that of a novel, metal-alloy, penetrating anastomotic clip device., Materials and Methods: Forty-six fistulae were created in 23 sheep under a paired design using the nitinol U-Clip (n = 23) in one hind limb and continuous (n = 20) or interrupted (n = 3) polypropylene suture for the other. Animals were killed at 4 (n = 3), 14 (n = 3), 28 (n = 10), 42 (n = 3), and 180 (n = 4) days. Histological sections were evaluated for quantitative histology and immunohistochemistry., Results: Compared with continuous polypropylene, U-Clip specimens demonstrated less intima-media area per unit length (IMA/L), proliferating cells, and tissue necrosis at all time points (MANOVA, F = 9.8-24.1, all p ≤ .005; observed power >82%). Specifically, values of IMA/L were reduced by 5% (p = .97), 37% (p = .02), 33% (p < .01), 9% (p = .42), and 14% (p = .22) at the time points of 4, 14, 28, 42, and 180 days respectively. Proliferating cells were reduced by 75% (p < .01), 72% (p = .03), 76% (p = .03), 27% (p = .31), and 60% (p = .01) and tissue necrosis by 67% (p < .01), 58% (p = .02), 40% (p = .33), 21% (p = .43), 77% (p = .11). In a 28-day comparison between U-Clip and interrupted polypropylene the U-Clip group demonstrated a 4% (p = .65) reduction in IMA/L, 74% (p < .01) in proliferating cells and 49% (p < .05) in tissue necrosis., Conclusions: These results provide evidence of reduced local tissue necrosis, proliferating cells, and IH, favouring arteriovenous fistulae created using the U-Clip anastomotic device over conventional polypropylene suture techniques most evident over the first 4 weeks., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

The popliteal artery (PA) may well be the most challenging of all infra-inguinal vessels to treat. Not only is it anatomically unique but it's also exposed to some of the most brutal forces seen in the lower limb, during normal knee flexion. Management may be challenging and with few randomized trials dedicated to answering questions of technical success and durability the correct approach remains contentious. Herein we seek to describe and evaluate the growing number of options for treatment in this vascular territory.

The use of endovascular techniques for the treatment of occlusive arterial disease below the knee has gained widespread acceptance and is considered by many as the first line treatment for patients with critical limb ischaemia. Tibial angioplasty and stenting have a high rate of technical success and are relatively low risk procedures, which has widened their applicability to include treatment for the elderly and those with comorbidities unsuitable for open bypass surgery. Despite these advantages the durability of the percutaneous revascularisation remains inferior to that of open surgery for diffusely diseased arteries. In the search to improve their long term performance we have sought to investigate the role of coronary drug eluting stents (DES) in the tibial vasculature in the hope that they may reduce recurrent stenosis, the leading threat to interventional patency. Ample data now exists in the form of registries and randomised trials designed to evaluate the use of DES in the crural arteries below the knee. This article reviews this body of research, explores the use of these devices in more complex lesions, speculates on their future development and examines their cost-effectiveness.

The treatment of peripheral arterial occlusive disease with endovascular therapy is rapidly becoming the standard of care. Akin to the movement towards percutaneous coronary interventions that occurred with gusto throughout the 1980s and 1990 s, treatment for the peripheral vasculature has undergone its own paradigm shift. Such that many feel that a first-line catheter-based approach is justified for the majority of patients in 2012. Extensive occlusive disease of the aorto-iliac segment is an area where open surgery has historically been preferred over endovascular therapy. This is partly because the open surgical standard of aorto-bi-femoral bypass has durability unrivalled by other forms of peripheral revascularisation surgery. Furthermore, some have avoided endovascular interventions in this region because of fears of perforation, bleeding and limited technical success in an area where the blood vessels carry a heavy burden of disease and a large thrombotic load. Throughout surgical history we have seen advances in technology emerge to provide a medium through which the proceduralist may extend their indications for treatment. A number of re-entry devices which provide a reliable method of wire passage beyond chronic occlusions of the aorta and iliac arteries have emerged and for the first time are safely facilitating high technical success rates in the treatment of aorto-iliac occlusive disease (AIOD). What follows is a summary of both open and endovascular treatment options for AIOD. Moreover, this review will provide an evidence based description of the emerging litany of devices which aid in wire passage through this most challenging of vascular territories.

Objectives: The aim of this study was to create an ovine arteriovenous fistula (AVF) model which would closely replicate a human forearm fistula and use this to quantify the degree of intimal hyperplasia in those created with the U-Clip compared to a conventional sutured anastomosis., Materials and Methods: Twenty AVFs were created in 10 Border Leicester-Merino sheep between the superficial femoral artery and vein of each hind limb. On one side the U-Clip and on the other a continuous polypropylene suture was used to perform the anastomosis. The animals were sacrificed at 2 (n = 3), 4 (n = 4), 6 (n = 3) weeks and histological slices were taken of each AVF in cross section to determine the intimal media area per unit length (IMA/L)., Results: Intimal hyperplasia (IH) was observed at all time points with one AVF found occluded with thrombus at the time of harvest. The IMA/L was significantly lower in the U-Clip groups by 24% at 2 weeks, 32% at 4 weeks and 23% at 6 weeks (Two-way ANOVA, p = 0.019, observed power = 0.825, time or side p ≥ 0.766, type p = 0.001; Paired t-test, p < 0.001 between matched anastomotic types). Time taken to perform the anastomosis was similar between the two anastomotic techniques (Polypropylene 14(8-18) vs. U-Clip 15.3(11-23) min; p = 0.47)., Conclusion: This ovine AVF model results in IH similar to that seen in a human AVF. The IH that occurs with the U-Clip is less than that of continuous polypropylene suture., (Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: To describe a technique to approach chronic total occlusions (CTOs) of the superficial femoral artery (SFA) after failed antegrade recanalization as an alternative to a conventional transpopliteal approach., Methods: A retrospective analysis was undertaken of 50 patients (37 men; mean age 71 years) who underwent retrograde recanalization via a distal SFA access after failed antegrade recanalization of SFA CTOs that were not beyond the adductor canal. Antegrade recanalization failed due to flush SFA occlusion, occluded stents, wire perforation, and re-entry failure. Retrograde SFA access required introduction of a 7- to 15-cm, 21-G needle distal to the occlusion. A 0.018-inch guidewire was inserted through the needle followed by a 4- or 6-F, 10-cm sheath or dedicated support catheter only. All retrograde SFA punctures were performed with the patient in the supine position. Once retrograde passage of the occlusion was successful, oftentimes requiring a "double-balloon" technique to disrupt the dissection membrane with abutting balloons delivered from both access sites, balloon angioplasty and/or stenting could be performed from either direction., Results: Retrograde puncture of the distal SFA was successful in all cases. Retrograde recanalization involved insertion of a 6-F sheath in 3 (6%) cases, a 4-F sheath in 32 (64%), and a sheathless approach in 15 (30%). The "double-balloon" technique was necessary to achieve guidewire passage in 12 cases. Recanalization was successful in 48 (96%) cases. Hemostasis time at the distal puncture site was 9.2 minutes (range 3-30). Perioperative complications included 4 pseudoaneurysms (2 groins, 2 distal), 1 peripheral embolization, and 1 small arteriovenous fistula at the distal puncture site., Conclusion: For failure of antegrade recanalization of SFA occlusions, the retrograde SFA puncture distal to the adductor canal with the patient remaining supine is a safe and successful technique that represents a convenient alternative to the conventional transpopliteal approach.

A 56-year-old male with a past history of coronary artery bypass graft surgery underwent stent implantation for a severe proximal left subclavian artery stenosis. Recurrent in-stent restenosis (ISR) resulted in the coronary subclavian steal syndrome (CSSS), with angina due to compromised blood flow in the left internal mammary artery/radial composite bypass graft. This was treated with cutting balloon predilatation followed by paclitaxel-coated balloon (PCB) dilatation, with an excellent angiographic result. At 10 months of follow-up, blood pressure in both arms was equal, and the patient remained symptom free. To our knowledge, this is the first report of successful treatment of subclavian ISR causing CSSS with a PCB., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: To report a retrospective, single-center study that evaluates technical and clinical outcomes from subintimal recanalization of femoropopliteal chronic total occlusions (CTO) facilitated by the Outback re-entry catheter., Methods: The Outback catheter was required to complete recanalization of femoropopliteal CTOs (mean lesion length 195 ± 91 mm) in 118 limbs of 113 patients (77 men; mean age 70 ± 10 years). In 80/118 (67.8%) limbs, treatment was performed for claudication and in the remaining 38 (32.2%) for critical limb ischemia (CLI). Technical and procedural success, clinical outcome, and cumulative patency rates in follow-up were evaluated., Results: Re-entry was accomplished in 108/118 limbs (91.5%) with recanalization completed in 107/118 (90.7%). Of these, only 61/107 (57%) arteries were left with a residual stenosis <30%. Complications included minor bleeding of the target vessel (5/118, 4.2%) and minor hematoma/pseudoaneurysm at the access site (6/118, 5.1%). Acute reocclusion developed in 2/118 cases (1.7%) without major complication. After 12 months, primary patency was 56.7%, assisted primary patency 83.1%, and secondary patency 89.1%. Primary patency was significantly reduced in limbs with residual stenosis. Over a median 15-month follow-up (range 2-32), 4 major and 2 minor amputations were performed in patients with CLI., Conclusion: The Outback catheter is a reliable tool to recanalize challenging chronic femoropopliteal occlusions after failed guidewire re-entry. Restenosis rates are high, which may be due to the severity and extent of disease in these patients, who are particularly challenging.

Objectives: Considerable evidence exists for the use of arm vein conduit in lower limb bypass surgery. The use of arm vein in preference to synthetic conduit as a last autogenous option was assessed for patency and limb salvage outcomes., Materials and Methods: A prospective database was interrogated and checked against TQEH operating theatre database to detect all infrainguinal arm vein bypasses performed between 1997 and 2005. Patency, limb salvage and survival data for 37 arm vein bypasses was calculated using the Kaplan-Meier survival estimate method., Results: There were no perioperative deaths. 30 day patency rates were 89% primary, 95% secondary and 95% limb salvage. 12 month patency rates were 56% primary, 79% secondary and 91% limb salvage. 5 year patency rates were 37% primary, 76% secondary and 91% limb salvage. There was no significant patency advantage for primary vs. "redo" grafts (p=0.54), single vessel vs. spliced conduits (p=0.33) or popliteal vs tibial outflow (p=0.80). Patient survival rate was 92% and 65% at 1 and 5 years respectively., Conclusion: Lower limb bypasses using arm vein can be performed with favourable patency and limb salvage compared to synthetic conduits. However, secondary interventions are frequently required to maintain patency. We recommend a vigilant surveillance program for early identification of patency threatening disease.

Objective: To determine the influence of IL-1 on the arterial response to experimental injury in porcine models of percutaneous coronary intervention (PCI)., Methods: An intravenous (i.v.) bolus of 0.5 mg/kg followed by a subcutaneous (s.c.) infusion of 2 mg/kg/24 h of human IL-1 receptor antagonist (IL-1ra) inhibited neutrophil recruitment in response to intradermal IL-1. Using this dose regimen, five groups of pigs were studied: Group 1, oversized balloon angioplasty of 2 coronary vessels (14-day infusion, 28th day sacrifice and analysis); Groups 2, 3, 4, and 5, oversized stenting of 2 coronary vessels (Group 2: 14-day infusion, 28th day analysis; Group 3: 14-day infusion, 14th day analysis; Group 4: 28-day infusion, 28th day analysis; Group 5: 28-day infusion, 90th day analysis). Neointimal area was quantified by standard means., Results: In Group 1, IL-1ra resulted in a 23% decrease in neointimal area (p=0.04); in Group 2, a 34% increase (p=0.001); in Group 3, a 38% decrease (p<0.0001); in Group 4, a 34% decrease (p=0.0004); and in Group 5, a 41% decrease (p=0.00001)., Conclusions: IL-1ra was associated with a sustained, significant reduction in neointima after vessel wall injury as long as it is given for the duration of the stimulation of the IL-1 system, in this case at least 28 days. This suggests that therapies based on the antagonism of IL-1 may modulate the coronary artery response to injury.

Impaired pulmonary release of nitric oxide (NO) is one of the characteristic phenotypic changes of vascular cells in pulmonary hypertension. The aim of this study was to determine nitric oxide synthase (NOS)-dependent whole body NO production in patients with primary pulmonary hypertension. NOS-dependent whole body NO production was assessed by giving an intravenous infusion of L-[(15)N](2)-arginine (50 micromol/min for 30 min) and measuring isotopic urinary enrichment of (15)N-nitrite and (15)N-nitrate. Four female patients with no signs of infection were recruited and compared with 6 age-matched control subjects. Mean 12-hour excretion of (15)N-nitrite and (15)N-nitrate in the total urine over 36 h was smaller in patients than in control subjects (57.2 +/- 27.6 vs. 229.1 +/- 65.2 nmol/mmol creatinine, p < 0.01, Mann-Whitney U test, respectively). Neither mean 12-hour excretion of (14)N-nitrite and (14)N-nitrate (51.6 +/- 10.0 vs. 72.4 +/- 10.0 micromol/mmol creatinine, p = 0.3) nor glomerular filtration rates (84.5 +/- 15.8 vs. 129.7 +/- 16.0 ml/min, p = 0.1) were different between patients and control subjects. Our results suggest that either basal NOS-dependent whole body NO production is impaired or excess NO metabolism occurs in patients with primary pulmonary hypertension., (Copyright 2005 S. Karger AG, Basel.)

A study of urea and albumin metabolism was carried out in a patient with the stagnant loop syndrome and in a control subject using radioisotopic and stable isotopic techniques. The patient had a higher rate of urea synthesis, urea hydrolysis in the gut, and of incorporation of recycled urea nitrogen into albumin. Although only a small proportion (0.4%) of the urea nitrogen available was used for albumin synthesis and this constituted only 0.8% of the daily nitrogen requirement for this purpose, the reutilization of nitrogen was relatively much greater than was observed in the control study.

1. The relation between endogenous urea metabolism and albumin synthesis has been studied in ten patients with chronic renal failure and in four normal subjects, after single intravenous injections of [14-C]urea,[15-N]urea and 125-I-labelled albumin. 2. The rate of urea synthesis was determined from the dynamics of plasma [14-C]urea specific radioactivity and the rate of urea metabolism was estimated from the relative rates of urea synthesis and urea appearance in urine and body water. Deconvolution analysis of plasma [15N]albumin enrichmevt and 125-i-labelled albumin radioactivity yielded the cumulative incorporation of 15-N into total exchangeable albumin and enabled calculation of the absolute rate of urema nitrogen utilization for albumin synthesis. 3. Although the mean absolute rate of urea degradation in uraemic patients (3-7 mmol/h) was higher than in normal subjects (2-3 mmol/h) there was no significant positive correlation between urea degradation and plasma urea concentration. 4. In uraemic subjects, there was a significant positive correlation between urea synthetic rate and urea degration rate. 5. The rate of utilization of urea nitrogen for albumin synthesis was low, but was very much higher in uraemic subjects (mean 83-8 mumol/h) compared with normal subjects (mean 6-4 mumol/h), as was the provision by urea of the nitrogen required for albumin synthesis in uraemic subjects (2-37%) compared with normal subjects (0-13%). 6. The efficiency of utilization of urea nitrogen for albumin synthesis was higher in the uraemic patients (1-3%) than the normal subjects (0-2%), and was higher in those patients with chronic renal failure who received a 30 g protein diet than those on 70 g of protein. A significant negative correlation was noted between efficiency of urea nitrogen utilization and the rate of synthesis of albumin. 7. These studies suggest the presence of a mechanism for the conservation of urea nitrogen in chronic renal failure which is unrelated to the extent of urea degradation, and which can only be partly explained by the higher proportion of intraluminal gut nitrogen derived from urea.