Systematic literature review comparing clinical utility of heparin-bonded expanded polytetrafluoroethylene graft to autologous saphenous vein graft for management of below-knee peripheral arterial disease.

INTRODUCTION: This systematic literature review compares the clinical outcomes of heparin-bonded expanded polytetrafluoroethylene with autologous saphenous vein in the management of patients undergoing below-the-knee bypass to treat peripheral arterial disease. METHODS: An electronic literature search was conducted in MEDLINE and EMBASE to identify comparative studies in patients undergoing below-the-knee surgical bypass. Studies were screened at abstract and full text review using pre-defined inclusion criteria by two independent reviewers and critically appraised for risk of bias. Meta-analyses were conducted using Review Manager 5 software (Nordic Cochrane Centre, Copenhagen, Denmark). RESULTS: Eight retrospective cohort studies were identified. Meta-analysis of primary patency demonstrated no significant difference between heparin-bonded expanded polytetrafluoroethylene and autologous saphenous vein grafts after one year (0.91 [0.52-1.59], P=0.74), two years (1.12 [0.60-2.10], P=0.77), three years (0.62 [0.26-1.48], P=0.28) and 4 years [0.36 -1.39], P=0.31). Similarly, for secondary patency, no significant difference was detected at one (0.62 [0.33-1.15], P=0.13), two (0.83 [0.32-2.13], P=0.69), three (0.60 [0.27-1.32], P=0.20) and 4 years (0.66 [0.32-1.36], P=0.26) respectively. There was no significant difference between autologous veins and heparin-bonded expanded polytetrafluoroethylene for limb salvage and mortality at all timepoints. A sensitivity analysis to compare outflow vessel was conducted in only tibial bypass identified no differences. All analyses were considered at high-risk bias due to heterogeneity in study populations and attrition in follow-up. CONCLUSION: This meta-analysis demonstrates similar outcomes between autologous saphenous vein and heparin-bonded expanded polytetrafluoroethylene for patency, limb salvage, and mortality through 4 years. Primary and secondary patency are superior at four years with autologous veins, but limb salvage and overall survival remained similar. The use of heparin-bonded expanded polytetrafluoroethylene synthetic grafts is a satisfactory option to prevent amputation, particularly when autologous saphenous vein grafts are not available. Controlled clinical studies are needed to further inform future decision making and economic modeling related to the choice of conduit for below-the-knee graft construction.

The role of sealants for achieving anastomotic hemostasis in vascular surgery.

BACKGROUND: During vascular interventions, connections that link arteries, veins, or synthetic grafts, which are known as an 'anastomosis', may be necessary. Vascular anastomoses can bleed from the needle holes that result from the creation of the anastomoses. Various surgical options are available for achieving hemostasis, or the stopping of bleeding, including the application of sealants directly onto the bleeding vessels or tissues. Sealants are designed for use in vascular surgery as adjuncts when conventional interventions are ineffective and are applied directly by the surgeon to seal bleeding anastomoses. Despite the availability of several different types of sealants, the evidence for the clinical efficacy of these hemostatic adjuncts has not been definitively established in vascular surgery patients. OBJECTIVES: To evaluate the benefits and harms of sealants as adjuncts for achieving anastomotic site hemostasis in patients undergoing vascular surgery. SEARCH METHODS: The Cochrane Vascular Information Specialist conducted systematic searches of the following databases: the Cochrane Vascular Specialised Register via the Cochrane Register of Studies; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE via Ovid; Embase via Ovid ; and CINAHL via EBSCO. We also searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for clinical trials. Reference lists of included trials and relevant reviews were also searched. The latest search date was 6 March 2023. SELECTION CRITERIA: We included randomized controlled trials that compared fibrin or synthetic sealant use with alternative interventions (e.g. manual compression, reversal of anticoagulation) for achieving anastomotic-site hemostasis in vascular surgery procedures. We included participants who underwent the creation of an anastomosis during vascular surgery. We excluded non-vascular surgery patients. DATA COLLECTION AND ANALYSIS: We have used standard Cochrane methods. Our primary outcomes were time to hemostasis, failure of hemostatic intervention, and intraoperative blood loss. Our secondary outcomes were operating time, death from bleeding complications up to 30 days, postoperative bleeding up to 30 days, unplanned return to the operating room for bleeding complications management up to 30 days, quality of life, and adverse events. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We found 24 randomized controlled trials that included a total of 2376 participants who met the inclusion criteria. All trials compared sealant use with standard care controls, including oxidized cellulose, gelatin sponge, and manual compression. All trials were at high risk of performance bias, detection bias, and other sources of bias. We downgraded the certainty of evidence for risk of bias concerns, inconsistency, imprecision and possible publication bias. Combining data on time to hemostasis showed that sealant use may reduce the mean time to hemostasis compared to control (mean difference (MD) -230.09 seconds, 95% confidence interval (CI) -329.24 to -130.94; P < 0.00001; 7 studies, 498 participants; low-certainty evidence). Combining data on failure of hemostatic intervention showed that sealant use may reduce the rate of failure compared to control, but the evidence is very uncertain (risk ratio (RR) 0.46, 95% CI 0.35 to 0.61; P < 0.00001; 17 studies, 2120 participants; very low-certainty evidence). We did not detect any clear differences between the sealant and control groups for intraoperative blood loss (MD -32.69 mL, 95% CI -96.21 to 30.83; P = 0.31; 3 studies, 266 participants; low-certainty evidence); operating time (MD -18.72 minutes, 95% CI -40.18 to 2.73; P = 0.09; 4 studies, 436 participants; low-certainty evidence); postoperative bleeding (RR 0.78, 95% CI 0.59 to 1.04; P = 0.09; 9 studies, 1216 participants; low-certainty evidence), or unplanned return to the operating room (RR 0.27, 95% CI 0.04 to 1.69; P = 0.16; 8 studies, 721 participants; low-certainty evidence). No studies reported death from bleeding or quality of life outcomes. AUTHORS' CONCLUSIONS: Based on meta-analysis of 24 trials with 2376 participants, our review demonstrated that sealant use for achieving anastomotic hemostasis in vascular surgery patients may result in reduced time to hemostasis, and may reduce rates of hemostatic intervention failure, although the evidence is very uncertain, when compared to standard controls. Our analysis showed there may be no differences in intraoperative blood loss, operating time, postoperative bleeding up to 30 days, and unplanned return to the operating room for bleeding complications up to 30 days. Deaths and quality of life could not be analyzed. Limitations include the risk of bias in all studies. Our review has demonstrated that using sealants may reduce the time required to achieve hemostasis and the rate of hemostatic failure. However, a significant risk of bias was identified in the included studies, and future trials are needed to provide unbiased data and address other considerations such as cost-effectiveness and adverse events with sealant use.

Learning curve and proficiency metrics for transcarotid artery revascularization.

BACKGROUND: When introduced to a new procedure, physicians improve their performance and reduce their procedural adverse event rates rapidly during the initial cases and then improvement slows, signaling that proficiency has been achieved. Determining when they have acquired proficiency has important implications for procedural innovation, education, credentialing, and patient safety. We analyzed the worldwide experience with transcarotid artery revascularization (TCAR), a hybrid approach to carotid revascularization, to identify the (1) procedural performance measures associated with clinical and technical adverse events; (2) target levels of performance measures that minimize adverse event rates; and (3) number of TCAR cases needed to achieve the target levels for the performance measures. METHODS: The patient, lesion, and physician characteristics were collected for each TCAR procedure performed by each physician worldwide in an international quality assurance database. Four procedural performance measures were recorded for each procedure: flow-reversal time, fluoroscopy time, contrast volume, and total skin-to-skin time. Composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure), occurring within 24 hours were also recorded. Correlations between each performance measure and the clinical and technical adverse event rates were computed. The inflection points in the performance measures were identified at which no further improvements occurred in the adverse event rates. Finally, the minimum number of TCAR cases required to achieve the target performance measure levels was computed. RESULTS: A total of 18,240 procedures performed by 1273 physicians were analyzed. Of the 18,240 patients, 34.9% were women and 62.5% were asymptomatic. The flow-reversal time correlated with clinical adverse events adjusted for age, sex, and symptomatic status (R2 = 0.91; P < .0001) and adjusted technical adverse events (R2 = 0.86; P < .0001). The skin-to-skin time correlated with adjusted technical adverse events (R2 = 0.92; P < .0001). A reduction in flow-reversal times to <13.1 minutes and the skin-to-skin time to <81 minutes did not translate into further improvements in the adverse event rates. A minimum of 26 TCAR cases was required to achieve the target flow-reversal time, and a minimum of 15 cases was required to achieve the target skin-to-skin time. CONCLUSIONS: The flow-reversal time and skin-to-skin time are appropriate performance measures for establishing the level of expertise of physicians as they acquire skills to perform TCAR. A target time of ≤13.1 minutes for flow-reversal and 81 minutes for skin-to-skin time minimized the adverse event rates. Familiarity with the steps involved in performing TCAR was achieved after ≥15 cases, and minimizing clinical adverse events occurred after ≥26 cases.

The impact of the SARS-CoV-2 pandemic on the management of chronic limb-threatening ischemia and wound care.

In the wake of the coronavirus pandemic, the critical limb ischemia (CLI) Global Society aims to develop improved clinical guidance that will inform better care standards to reduce tissue loss and amputations during and following the new SARS-CoV-2 era. This will include developing standards of practice, improve gaps in care, and design improved research protocols to study new chronic limb-threatening ischemia treatment and diagnostic options. Following a round table discussion that identified hypotheses and suppositions the wound care community had during the SARS-CoV-2 pandemic, the CLI Global Society undertook a critical review of literature using PubMed to confirm or rebut these hypotheses, identify knowledge gaps, and analyse the findings in terms of what in wound care has changed due to the pandemic and what wound care providers need to do differently as a result of these changes. Evidence was graded using the Oxford Centre for Evidence-Based Medicine scheme. The majority of hypotheses and related suppositions were confirmed, but there is noticeable heterogeneity, so the experiences reported herein are not universal for wound care providers and centres. Moreover, the effects of the dynamic pandemic vary over time in geographic areas. Wound care will unlikely return to prepandemic practices. Importantly, Levels 2-5 evidence reveals a paradigm shift in wound care towards a hybrid telemedicine and home healthcare model to keep patients at home to minimize the number of in-person visits at clinics and hospitalizations, with the exception of severe cases such as chronic limb-threatening ischemia. The use of telemedicine and home care will likely continue and improve in the postpandemic era.

Surgical Deep Vein Arterialization: Adding to the Armamentarium of Complex Limb Salvage.

BACKGROUND: Patients with severe peripheral arterial disease with limited or nonexistent arterial runoff, the so-called "desert foot", challenge efforts at limb preservation. Deep vein arterialization (DVA) involves incorporating a venous target as an outflow to achieve revascularization in these complex patients. We report outcomes in an initial series of patients undergoing DVA as a component of surgical bypass. METHODS: Over a 2-year period, 10 patients underwent bypass incorporating DVA due to severely disadvantaged runoff using a heparin-bonded expanded polytetrafluoroethylene conduit. Indications for surgery included tissue loss (8) or ischemic rest pain (2) in patients who had failed endovascular (3) or surgical (7) revascularization. Inflow arteries for bypass ranged from external iliac to below knee popliteal. Outflow anastomoses incorporated a common ostium arteriovenous fistula between anterior tibial (5), posterior tibial (2), peroneal (1) or plantaris pedis (2) arteries, and corresponding tibial veins. Prior to anastomotic completion, tibial vein valves were lysed to allow venous arterialization by a way of retrograde flow. Postoperative medical regimen included dual antiplatelet (2), antiplatelet plus anticoagulation (7), or anticoagulation alone (1). RESULTS: Primary patency was maintained in 7 of 10 grafts (average: 4.1 months, range: 1-18 months). Limb salvage was achieved in 8 of 10 patients (average: 6 months, range: 1-18 months). Two below knee amputations were performed after graft occlusion due to extensive tissue loss and infection, whereas 1 patient maintained limb salvage despite graft occlusion after successful wound healing. CONCLUSIONS: This initial experience describes surgical DVA using a prosthetic conduit in conjunction with an arteriovenous fistula at the distal anastomosis in patients with threatened limb loss and severely disadvantaged tibial runoff. Although evidence for long-term efficacy is uncertain, preliminary outcomes warrant further investigation as this technique may allow for surgical revascularization resulting in limb preservation for patients with no other alternative than amputation.

Effects of Peripheral Arterial Disease Interventions on Survival: A Propensity-Score Matched Analysis Using VQI Data.

BACKGROUND: Atherectomy is currently being used extensively for occlusive peripheral artery disease (PAD) interventions without proven benefits. This analysis examines the effects of atherectomy and other endovascular interventions on patient survival. OBJECTIVES: The aim of this study is to compare overall survival for patients undergoing PAD endovascular interventions, such as plain old balloon angioplasty (POBA), stent deployment and atherectomy. METHODS: Propensity score matched cohorts were constructed to conduct pairwise comparisons of overall survival in patients who underwent stenosis and occlusive PAD interventions between May 2011 and February 2020 using Vascular Quality Initiative (VQI) regional registry data. Inverse probability treatment weighting method was used to compare secondary outcomes of in-hospital mortality, length of stay, complications and major amputations. Comparative analysis was performed for POBA vs stenting, POBA vs atherectomy, and stenting vs atherectomy. RESULTS: A total number of 15281 eligible cases were identified. After propensity score matching, 6094, 4032, and 3312 cases were used to compare POBA versus stent deployment, POBA versus atherectomy and stent versus atherectomy, respectively. Stent deployment had significantly better overall survival compared with POBA and atherectomy (P < 0.001). Multivariable Cox proportional hazard models suggested stenting was associated with a reduction in mortality hazard by 30% compared with POBA (HR: 0.7; 95% CI: 0.6-0.82; P < 0.001) and a 40% mortality reduction compared with atherectomy (HR: 0.6; 95% CI: 0.48-0.75; P < 0.001). No significant difference was found between POBA and atherectomy. There was no statistical difference in other secondary outcomes which were comparable among all cohorts. CONCLUSIONS: Stent deployment was significantly superior to POBA and atherectomy in terms of overall survival with comparable complication and amputation rates. The natural history of PAD patients presenting with claudication is associated with an extremely low annual mortality risk. Therefore, further examinations of outcomes, especially in regards to mortality rates, both POBA and atherectomy on the management of PAD patients especially those presenting with claudication is warranted.

Novel Therapies for Critical Limb-Threatening Ischemia.

PURPOSE OF REVIEW: This review intends to discuss the latest endovascular and surgical advancement in the treatment of critical limb-threatening ischemia (CLTI). RECENT FINDINGS: We discuss novel endovascular technological advancements such as intravascular lithotripsy, the Tack endovascular stent, the PQ Bypass DETOUR system, and the LimFlow System for deep venous arterialization (DVA) in the very high risk "no-option" CLTI population. We also discuss the increasing adoption of radial and pedal approaches for endovascular revascularization and the tibiopedal arterial minimally invasive (TAMI) technique. On the surgical front, we discuss the distal vein patch technique and surgical and hybrid DVA. Recent advancements in the treatment options of CLTI will likely lead to reducing the rate of major amputations if they are adopted in a collaborative environment in order to apply the most appropriate treatment option to each individual patient based on the anatomy, comorbidities, functional status, and local expertise.

A novel technique using long segment patch angioplasty maturation to increase the maturation rate of arteriovenous fistulas.

OBJECTIVE: Given the superior patency of arteriovenous fistulas (AVFs) and the decreased risk of infection compared with arteriovenous grafts, the Kidney Disease Outcomes Quality Initiative guidelines have recommended the fistula-first approach. However, ∼20% to 60% of all fistulas will fail to mature. We have described our experience with a novel technique using bovine pericardial patch angioplasty to increase the rate of AVF maturation. METHODS: We used 2-cm × 9-cm-long or 2.5-cm × 15-cm-long segment pericardial patch angioplasty to assist in the maturation of AVFs. A single-center, retrospective cohort study was conducted of all patients who had undergone patch angioplasty maturation (PAM) for AVFs that had failed to mature. The outcomes of interest were maturation status and patency, censored by the death and last known follow-up dates. RESULTS: From March 2007 to October 2019, 139 patients had undergone PAM. Follow-up data were available for 137 of the 139 patients (98.6%), with 126 AVFs (92.0%) progressing to maturation. Of the 126 patients with AVFs that had progressed to maturity, the previous hemodialysis (HD) method was known for 88 patients (69.8%). Of these 88 patients, 70 (79.5%) had previously been receiving HD via an HD catheter. Using a Kaplan-Meier estimator censored for death and loss to follow-up, the assisted primary patency rates at 1, 2, and 3 years were 87.3%, 78.1%, and 68.0%, respectively. Of the 137 patients, 69 (54.8%) had required no additional interventions after patch angioplasty. The complications requiring intervention were stenosis (n = 45; 32.8%), thrombosis (n = 10; 7.3%), infection (n = 3; 2.2%), steal syndrome (n = 3; 2.2%), noninfected wound complications (n = 1; 0.8%), and pseudoaneurysm (n = 1; 0.8%). The average interval to intervention after patch angioplasty was 4.56 months. CONCLUSIONS: Long-segment bovine pericardial PAM can be performed safely to treat nonmaturing AVFs, with a 92.0% successful maturation rate and patency rates comparable to those for AVFs. PAM should be a consideration for patients with nonmaturing AVFs.

Common femoral vein obstruction secondary to femoral sheath lipoma.

Common femoral vein obstruction secondary to femoral sheath lipomas are rare. We describe the case of a 49 year-old male that presented to the clinic with a 3 month history of progressive right lower extremity pain, edema and discoloration. Venous duplex imaging was consistent with proximal venous obstruction and led to Computerized Tomographic Venography (CTV) which demonstrated a large mass obstructing the external iliac vein (EIV) and common femoral vein (CFV) consistent with a femoral sheath lipoma. Surgical exploration revealed a large well encapsulated lipoma in the right femoral sheath posterior to the CFV and external iliac vein causing near occlusion. We present an overview of the diagnosis and surgical management of symptomatic femoral vein obstruction caused by a large femoral sheath lipoma.

Digital Subtraction Angiography Prior to an Amputation for Critical Limb Ischemia (CLI): An Expert Recommendation Statement From the CLI Global Society to Optimize Limb Salvage.

Despite recent guideline updates on peripheral artery disease (PAD) and critical limb ischemia (CLI) treatment, the optimal treatment for CLI is still being debated. As a result, care is inconsistent, with many CLI patients undergoing an amputation prior to what many consider to be mandatory: consultation with an interdisciplinary specialty care team and a comprehensive imaging assessment. More importantly, quality imaging is critical in CLI patients with below-the-knee disease. Therefore, the CLI Global Society has put forth an interdisciplinary expert recommendation for superselective digital subtraction angiography (DSA) that includes the ankle and foot in properly indicated CLI patients to optimize limb salvage. A recommended imaging algorithm for CLI patients is included.

Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for the treatment of in-stent restenosis of the femoropopliteal arteries.

BACKGROUND: Stents are placed in the femoropopliteal arteries for numerous reasons, such as atherosclerotic disease, the need for dissection, and perforation of the arteries, and can become stenosed with the passage of time. When a stent develops a flow-limiting stenosis, this process is known as "in-stent stenosis." It is thought that in-stent restenosis is caused by a process known as "intimal hyperplasia" rather than by the progression of atherosclerotic disease. Management of in-stent restenosis may include performing balloon angioplasty, deploying another stent within the stenosed stent to force it open, and creating a bypass to deliver blood around the stent. The role of drug-eluting technologies, such as drug-eluting balloons (DEBs), in the management of in-stent restenosis is unclear. Drug-eluting balloons might function by coating the inside of stenosed stents with cytotoxic chemicals such as paclitaxel and by inhibiting the hyperplastic processes responsible for in-stent restenosis. It is important to perform this systematic review to evaluate the efficacy of DEB because of the potential for increased expenses associated with DEBs over uncoated balloon angioplasty, also known as plain old balloon angioplasty (POBA). OBJECTIVES: To assess the safety and efficacy of DEBs compared with uncoated balloon angioplasty in people with in-stent restenosis of the femoropopliteal arteries as assessed by criteria such as amputation-free survival, vessel patency, target lesion revascularization, binary restenosis rate, and death. We define "in-stent restenosis" as 50% or greater narrowing of a previously stented vessel by duplex ultrasound or angiography. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to November 28, 2017. Review authors also undertook reference checking to identify additional studies. SELECTION CRITERIA: We included all randomized controlled trials that compared DEBs versus uncoated balloon angioplasty for treatment of in-stent restenosis in the femoropopliteal arteries. DATA COLLECTION AND ANALYSIS: Two review authors (AK, WA) independently selected appropriate trials and performed data extraction, assessment of trial quality, and data analysis. The senior review author (AD) adjudicated any disagreements. MAIN RESULTS: Three trials that randomized a combined total of 263 participants met the review inclusion criteria. All three trials examined the treatment of symptomatic in-stent restenosis within the femoropopliteal arteries. These trials were carried out in Germany and Austria and used paclitaxel as the agent in the drug-eluting balloons. Two of the three trials were industry sponsored. Two companies manufactured the drug-eluting balloons (Eurocor, Bonn, Germany; Medtronic, Fridley, Minnesota, USA). The trials examined both anatomical and clinical endpoints. We noted heterogeneity in the frequency of bailout stenting deployment between studies as well as in the dosage of paclitaxel applied by the DEBs. Using GRADE assessment criteria, we determined that the certainty of evidence presented was very low for the outcomes of amputation, target lesion revascularization, binary restenosis, death, and improvement of one or more Rutherford categories. Most participants were followed up to 12 months, but one trial followed participants for up to 24 months.Trial results show no difference in the incidence of amputation between DEBs and uncoated balloon angioplasty. DEBs showed better outcomes for up to 24 months for target lesion revascularization (odds ratio (OR) 0.05, 95% confidence Interval (CI) 0.00 to 0.92 at six months; OR 0.24, 95% CI 0.08 to 0.70 at 24 months) and at six and 12 months for binary restenosis (OR 0.28, 95% CI 0.14 to 0.56 at six months; OR 0.34, 95% CI 0.15 to 0.76 at 12 months). Participants treated with DEBs also showed improvement of one or more Rutherford categories at six and 12 months (OR 1.81, 95% CI 1.02 to 3.21 at six months; OR 2.08, 95% CI 1.13 to 3.83 at 12 months). Data show no clear differences in death between DEBs and uncoated balloon angioplasty. Data were insufficient for subgroup or sensitivity analyses to be conducted. AUTHORS' CONCLUSIONS: Based on a meta-analysis of three trials with 263 participants, evidence suggests an advantage for DEBs compared with uncoated balloon angioplasty for anatomical endpoints such as target lesion revascularization (TLR) and binary restenosis, and for one clinical endpoint - improvement in Rutherford category post intervention for up to 24 months. However, the certainty of evidence for all these outcomes is very low due to the small number of included studies and participants and the high risk of bias in study design. Adequately powered and carefully constructed randomized controlled trials are needed to adequately investigate the role of drug-eluting technologies in the management of in-stent restenosis.

Initial in vitro and in vivo evaluation of a self-monitoring prosthetic bypass graft.

OBJECTIVE: Prosthetic grafts used for lower extremity revascularization and dialysis access fail because of hyperplastic stenosis and thrombosis. Graft surveillance is advocated to monitor function; however, graft failure can occur between episodic examinations. An innovative sensor with wireless, microchip technology allows automated surveillance with assessment of graft function using a "cloud"-based algorithm. We performed proof-of-concept experiments with in vitro and in vivo models to assess the feasibility such a real-time graft surveillance system. METHODS: A self-monitoring graft system was evaluated consisting of a prosthetic conduit of expanded polytetrafluoroethylene and a sensor unit, and a microsensor, microelectronics, battery, and remote processor with a monitor. The sensor unit was integrated on the extraluminal surface of expanded polytetrafluoroethylene grafts without compromise to the lumen of the conduit. The grafts were tested in vitro in a pulsatile, recirculating flow system under physiologic flow parameters. The hemodynamic parameters were varied to assess the ability to obtain wireless signal acquisition reflecting real-time flow properties in vitro. Segments of custom tubing with reduced diameters were inserted into the model to mimic stenosis proximal and distal to the grafts. After characterization of the initial data, the self-monitoring grafts were implanted in an ovine carotid model to assess proof of concept in vivo with 30-day follow-up of signal acquisition as well as arteriographic and histologic analysis. RESULTS: In vitro flow data demonstrated the device was able to determine factors related to prosthetic graft function under varied hemodynamic flow conditions. Wireless signal acquisition using Bluetooth technology (Bluetooth SIG, Inc, Kirkland, Wash) allowed remote data analysis reflecting graft flow parameters through changes in microsensor voltage and frequency. Waveform analysis was applied to construct an algorithm using proprietary software and determine a parameter for graft flow characteristics. This algorithm allowed determination of the degree of stenosis and location of stenosis location (proximal or distal) for display on a remote monitor in real time. Subsequent in vivo experiments confirmed the ability of the system to generate signal acquisition through skin and soft tissue under biologic conditions with no arteriographic stenosis and a favorable healing response at 30-day harvest. CONCLUSIONS: Initial in vitro and in vivo experiments demonstrate the ability for a self-monitoring graft system to remotely monitor hemodynamic parameters reflecting graft function using wireless data transmission. This automated system shows promise to deliver real-time data that can be analyzed by cloud-based algorithms alerting the clinician of a change in graft function or development of stenosis for further diagnostic study or intervention before graft failure.

Development of a Limb-Preservation Program.

In the global scenario, as the prevalence of renal failure and diabetes increases, healing and limb preservation assume increasing clinical importance for patients and healthcare systems. Unfortunately, there continues to be variation in the care delivered to patients at risk of losing a limb based on geography, race, socioeconomic status, and insurance status. There are also a variety of therapeutic approaches to patients with limb-threatening ischemia; 25% undergo primary amputation, 25% undergo medical therapy, and only 50% undergo any attempt at revascularization. Nearly 50% of patients undergoing major amputation have not had a simple diagnostic arteriogram to assess the possibility of limb preservation. The Society of Vascular Surgery and the American Podiatric Medical Association have recognized the benefits of a multidisciplinary approach to limb preservation. Benefits to the patient include rapid assessment, improved healing, and enhanced revascularization. Advantages for the providers include the ability to efficiently manage complex patients with help from the appropriate specialties, an increase in referrals, enhanced identity of the institution, and clinical research and trials. Such a program requires the coordinated effort of physicians, nurses, allied health professionals, and administrators dedicated to the preservation of functional limbs. Beneficial components include identifiable space, a vascular laboratory, hyperbaric oxygen therapy, and protocol-driven care involving diagnostic and therapeutic modalities such as endovascular revascularization, open bypass, and soft tissue reconstruction. Prosthetic expertise is also important to maintain function in those patients for whom amputation is appropriate. But, the key to a program is cooperation and communication among the participants who have a passion for limb preservation. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=452746.

The effect of congestive heart failure on perioperative outcomes in patients undergoing lower extremity revascularization.

BACKGROUND: As the management of peripheral arterial disease evolves, determining the factors affecting the outcome of lower extremity interventions is important. The presence of peripheral arterial disease is associated with a twofold increase in the prevalence of congestive heart failure (CHF), with reports of increased perioperative complications. This study evaluated CHF as a predictor of acute postoperative complications in patients undergoing lower extremity bypass. METHODS: The study group consisted of all patients entered in a prospective, multicenter database (American College of Surgeons National Surgical Quality Improvement Program) undergoing infrainguinal bypass (IIB) from 2005 to 2010. Patients with a new diagnosis of CHF ≤30 days before surgery were compared with those without such a diagnosis. Patency rates at 30 days, morbidity, and mortality were compared between groups using a multivariate logistic regression analysis controlling for covariates. RESULTS: There were 18,645 IIB patients, of which 488 (2.6%) had history of CHF. CHF patients were older and had higher rates of comorbidities than those without CHF. In univariate analysis, IIB graft failure was not significantly different for patients with CHF (6.8%) vs those without (5.2%; P = .13). There was no difference in patency for femoral popliteal grafts (no CHF, 96.5%; CHF, 96.3%; P = .89) or for femoral-tibial grafts (no CHF, 91.9%; CHF, 89.3%; P = .20). However, CHF was significantly associated with postsurgery cardiac events (P = .007), pneumonia, prolonged intubation, reintubation, sepsis, return to the operating room, 30-day mortality, and length of stay >9 days (all P < .0001). After adjusting for covariates associated with CHF, compared with patients without CHF, those with CHF had an 82% higher odds of postoperative pneumonia (95% confidence interval [CI], 13%-94%; P = .014), an 87% increase in the odds of prolonged intubation (95% CI, 16%-201%; P = .011), a 73% increase in the odds of reintubation (95% CI, 12%-167%; P = .014), a 55% increase in the odds of sepsis or septic shock (95% CI, 11%-118%; P = .011), a 29% increase in the odds of returning to the operating room (95% CI, 4%-61%; P = .022), a 121% increase in the odds of 30-day mortality (95% CI, 56%-214%; P < .0001), and a 102% increase in the odds of postsurgery length of stay >9 days (95% CI, 64%-148%; P < .0001). CONCLUSIONS: Recently diagnosed or exacerbated CHF does not affect acute IIB graft patency. However, CHF may increase the complication rates for perioperative pneumonia, prolonged intubation, reintubation, sepsis, return to the operating room, extended length of stay, and mortality. Therefore, before pursuing lower extremity interventions in patients with a history of CHF, one should incorporate an individualized approach to optimize the success of the revascularization while minimizing medical comorbidities.

Postoperative complications after common femoral endarterectomy.

BACKGROUND: Common femoral endarterectomy (CFE) for limited arterial occlusive disease is considered a fairly low-risk operation of short duration. This study investigated the timing of 30-day outcomes as they related to hospital discharge and predicted the risk of operative mortality of this procedure. METHODS: All patients in the National Surgical Quality Improvement Program database who underwent isolated CFE between 2005 and 2010 were selected for the test sample. We identified postoperative mortality and morbidities occurring before and after hospital discharge. A risk calculator for 30-day mortality, developed in the test sample using logistic regression, was validated in a new sample of cases from 2011 to 2012. RESULTS: A total of 1843 CFEs reported from 2005 to 2010 met the inclusion and exclusion criteria. The average operative time was 146 ± 69.5 minutes (median, 133; interquartile range, 98-179 minutes), and 10% of patients needed to return to the operating room. The average length of stay was 4 ± 7.5 days (median, 3; interquartile range, 2-5 days); 91% of patients were discharged ≤ 1 week of surgery. Occurrences of cardiovascular events, renal dysfunction, and pulmonary complication were relatively low. There was 3.4% mortality and 8% wound-related complications, 30% and 86% of which occurred after hospital discharge, respectively. Overall, there was a 15% risk of combined mortality/morbidity, and >60% of these events occurred after discharge. The independent predictors of 30-day mortality were age, nonindependent functional status, preoperative dialysis, sepsis, emergency status, and American Society of Anesthesiologists Physical Status Classification 4 or 5, and the association between risk strata and death in the validation sample was strong (φ = 0.29) and significant (P < .001). CONCLUSIONS: CFE is not as "benign" a procedure as previously believed. The risks of death and wound complications are not insignificant, and a high percentage of these complications occurred after patients were discharged from the hospital. Patients should be carefully selected, especially in the elderly population, and close postoperative follow-up should be considered.

The effect of graft configuration on 30-day failure of infrapopliteal bypasses.

BACKGROUND: Despite advances in endovascular techniques, infrapopliteal bypasses are still required for limb salvage. Short-term graft patency is an important outcome parameter reflecting technical considerations and acute graft thrombosis. Both are important prerequisites for long-term patency. In this analysis, we compared the 30-day patency of all conduit configurations for infrapopliteal bypasses. METHODS: All primary infrapopliteal bypasses from the American College of Surgeons-National Surgical Quality Improvement Program database between 2005 and 2010 were divided into six groups: (1) great saphenous vein (GSV); (2) prosthetic conduit (prosthetic); (3) prosthetic conduit with a distal anastomotic venous adjunct (ADJ), such as a cuff or patch (prosthetic + ADJ); (4) composite graft of prosthetic and a vein segment (composite); (5) spliced autogenous vein (spliced vein); and (6) arm vein. Thirty-day graft failure, patient demographics, and operative details were compared among groups. A multivariate model was used for statistical analysis. RESULTS: A total of 5375 infrapopliteal bypasses were analyzed by conduit: GSV, 3983 (75%); prosthetic, 898 (17%); spliced vein, 160 (3%); prosthetic + ADJ, 112 (2%); arm vein, 93 (2%); and composite, 91 (2%). The difference among groups in demographics and comorbidities was not statistically significant. Perioperative mortality rates were similar among different conduits. After adjusting for sex, age, weight, race, and previous cardiac surgery, the bypass conduit had a significant independent association with 30-day graft patency (P = .006). The GSV failure rate was 7.5%. Composite had a significantly higher 30-day failure rate (15.4%, P = .006). There was no significant difference in 30-day failure rate of spliced vein (5.6%, P = .37) or arm vein (4.3%, P = .24) conduits compared with GSV. Prosthetic had significantly higher 30-day failure rate than GSV (10.5%, P = .004). The addition of adjuvant venous tissue at the distal anastomosis of prosthetic bypasses did not significantly improve their 30-day patency (failure rate of 9.8% for prosthetic + ADJ and 10.5% for prosthetic). There was no significant difference in graft patency between alternative venous conduits (arm vein/spliced vein) and prosthetic + ADJ. CONCLUSIONS: Venous conduits (GSV, spliced vein, arm vein) deliver the best 30-day patency for infrapopliteal bypasses, and GSV remains the most commonly used graft. Prosthetic grafts had a higher 30-day failure rate. Composite grafts should be abandoned because their early patency is not better than pure prosthetic conduits. The addition of a distal venous adjunct did not seem to improve acute prosthetic graft patency, which may reflect lack of effect on thrombogenicity rather than the myointimal hyperplastic response that effects long-term failure of infrapopliteal bypass.

Management of peripheral arterial disease in the context of a multidisciplinary limb program.

Peripheral artery disease (PAD) continues to increase in prevalence worldwide due to risk factors such as advanced age, diabetes mellitus, and obesity. Critical limb ischemia (CLTI) is the advanced form of PAD that can result in a lack of healing and limb loss as the most devastating consequence. Patients with PAD, especially CLTI, benefit from multidisciplinary care to optimize outcomes by reducing cardiovascular morbidity and mortality and preventing lower extremity amputation. Collaboration between various specialties allows a focus on problems involved in treating the patient with PAD including prevention, screening, medical care, wound care, infection, and revascularization when needed. Although there is no clear definition or consensus on the structure of the PAD team, certain guidelines are applicable to most clinical scenarios emphasizing "provider champions" in leading a clinical program. A vascular specialist (vascular surgery, interventional radiology, interventional cardiology) and a soft tissue specialist (podiatry, plastic surgery) are the typical "champions," often involving orthopedics, general surgery, vascular medicine, diabetology/endocrinology, infectious disease, nephrology, and rehabilitation medicine. The team should also include wound nurses, nutritionists, occupational therapists, orthotists, pharmacists, physical therapists, prosthetists, and social workers. This paper presents a brief overview of the structure of the multidisciplinary team with key components and functions of such a team to optimize treatment outcomes for PAD and CLTI.

Best practices for vascular arterial access and closure: a contemporary guide for the cardiac catheterization laboratory.

More than 1 million transcatheter-based cardiovascular procedures across the spectrum of interventional cardiology are performed annually in the United States. With the expanded indications for and increased complexities associated with these procedures, interventional cardiologists are expected to possess the requisite expertise to complete these interventions safely and effectively. While the art of vascular access and closure remains a prerequisite and critical skillset in contemporary practice, there remain significant variations in the techniques employed, resulting in the bleeding and vascular complications encountered in clinical practice. With an increasing recognition of the potential merits to standardized approaches to vascular access and closure, cardiovascular societies have put forth recommendations around best practices for performing these procedures in the cardiac catheterization laboratories. In this review, we aim to: (1) Examine the evolving definitions of bleeding and vascular complications; (2) Review best practices for transradial and transfemoral access and closure, including for large bore procedures; and (3) Highlight knowledge gaps and proposed areas of clinical research pertaining to vascular access which may inform clinical practice and potentially optimize the outcomes of patients undergoing transcatheter-based cardiac and vascular interventions.