Meta-analysis of alternate autologous vein bypass grafts to infrapopliteal arteries

Popliteal-to-Distal Extreme Bypass in Endovascular Era

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is characterized by rest pain and tissue loss, with an annual mortality rate of 20% and amputation rate of 40%, if not treated. Open bypass surgery is recommended in CLTI, depending on the availability of good quality venous material, outflow artery patency, and surgical expertise. The aim of the study is to analyze primary patency, limb salvage, and survival rate in patients undergoing popliteal-to-distal bypass.

METHODS

All consecutive patients who underwent popliteal-to-distal bypass surgery between January 2016 and December 2021 were enrolled in the study. Primary outcomes were primary patency, limb salvage, and overall survival. Secondary outcomes included amputation-free survival and secondary patency.

RESULTS

Forty-nine patients were included during the study. Technical success was achieved in 100% of cases. Target outflow artery was in 27% (n. 13) of cases the anterior tibial artery, in 27% (n. 13) the dorsalis pedis, in 2% (n. 1) the peroneal artery, in 30% (n. 15) the retromalleolar tibial artery, in 10% (n. 5) the medial plantar artery, and in 4% (n. 2) the tarsal artery. Two-year primary patency was 85% ± 5. Secondary patency rates were 86% ± 3 at 2 years. The overall survival was 81% ± 6 at 2 years, the amputation-free survival was 70% ± 9, and the limb salvage rate was 81% ± 6.

CONCLUSIONS

Popliteal-to-distal bypass requires high technical expertise to be performed. When a good autologous vein and adequate outflow artery are present, they can be feasible with good patency rates and overall survival.

Distal Adjuncts for High-Risk Lower Extremity Bypasses

BACKGROUND

This review will discuss the use of distal adjuncts for improving graft patency in high-risk lower extremity bypasses.

METHODS

Factors that contribute to the increased risk of failure in high-risk lower extremity bypasses, such as the use of nonautogenous conduits, the creation of bypasses to very distal arterial targets, and bypasses in patients with significant tibial arterial disease, will be discussed.

RESULTS

The use of surgical techniques such as creating venous cuffs, venous patches, and arteriovenous fistulas have been shown to improve the patency of high-risk bypasses.

CONCLUSIONS

Despite the increased risk of failure, the use of surgical adjuncts such as cuffs, patches, and arteriovenous fistulas can improve the patency rates of high-risk lower extremity bypasses.

Outcomes of lower extremity arterial bypass using the Human Acellular Vessel in patients with chronic limb-threatening ischemia

OBJECTIVE

Patients with chronic limb-threatening ischemia (CLTI) and no great saphenous vein to use as a conduit for arterial bypass have a high risk for amputation despite advances in medical and endovascular therapies. This report presents findings from a U.S. Food and Drug Administration (FDA) supported study of the Human Acellular Vessel (HAV) (Humacyte Inc.) used as a conduit for arterial bypass in patients with CLTI and inadequate or absent autologous conduit.

METHODS

The HAV is a 6-mm, 40-cm vessel created from human vascular smooth muscle cells seeded onto a polyglycolic acid scaffold pulsed in a bioreactor for 8 weeks as cells proliferate and the scaffold dissolves. The resultant vessel is decellularized, creating a nonimmunogenic conduit composed of collagen, elastin, and extracellular matrix. The FDA issued an Investigational New Drug for an intermediate-sized, single-center study of the HAV under the agency's Expanded Access Program in patients with advanced CLTI and inadequate or absent autologous conduit. Technical results and clinical outcomes were analyzed and reported.

RESULTS

Between March 2021 and July 2023, 29 patients (20 males; mean age, 71 ± 11 years) underwent limb salvage operation using the HAV as a bypass conduit. Most patients had advanced CLTI (Rutherford class 5/6 in 72%; wound, ischemia, and foot infection stage 3/4 in 83%), and 97% had previously failed revascularization(s) of the extremity. Two HAVs were sewn together to attain the needed bypass length in 24 patients (83%). Bypasses were to tibial arteries in 23 patients (79%) and to the popliteal artery in 6 (21%). Technical success was 100%, and the 30-day mortality rate was 7% (2 patients). With 100% follow-up (median, 9.3 months), the limb salvage rate was 86% (25/29 patients). There were 16 reinterventions to restore secondary patency, of which 15 (94%) were successful. Primary and secondary patency of the HAV at 9 months were 59% and 71%, respectively.

CONCLUSIONS

The HAV has demonstrated short- to intermediate-term safety and efficacy as an arterial bypass conduit in a complex cohort of patients with limb-threatening ischemia and no autologous options. This experience using the FDA's Expanded Access Program provides real-world data to inform regulatory deliberations and future trials of the HAV, including the study of the vessel as a first-line bypass conduit in less severe cases of chronic limb ischemia.

Current Status and Principles for the Treatment and Prevention of Diabetic Foot Ulcers in the Cardiovascular Patient Population: A Scientific Statement From the American Heart Association

Despite the known higher risk of cardiovascular disease in individuals with type 2 diabetes, the pathophysiology and optimal management of diabetic foot ulcers (DFUs), a leading complication associated with diabetes, is complex and continues to evolve. Complications of type 2 diabetes, such as DFUs, are a major cause of morbidity and mortality and the leading cause of major lower extremity amputation in the United States. There has recently been a strong focus on the prevention and early treatment of DFUs, leading to the development of multidisciplinary diabetic wound and amputation prevention clinics across the country. Mounting evidence has shown that, despite these efforts, amputations associated with DFUs continue to increase. Furthermore, due to increasing patient complexity of management secondary to comorbid conditions, such as cardiovascular disease, the management of peripheral artery disease associated with DFUs has become increasingly difficult, and care delivery is often episodic and fragmented. Although structured, process-specific approaches exist at individual institutions for the management of DFUs in the cardiovascular patient population, there is insufficient awareness of these principles in the general medicine communities. Furthermore, there is growing interest in better understanding the mechanistic underpinnings of DFUs to better define personalized medicine to improve outcomes. The goals of this scientific statement are to provide salient background information on the complex pathogenesis and current management of DFUs in cardiovascular patients, to guide therapeutic and preventive strategies and future research directions, and to inform public policy makers on health disparities and other barriers to improving and advancing care in this expanding patient population.

A systematic review and meta-analysis of primary bypass surgery compared with bypass surgery after endovascular treatment in peripheral artery disease patients

OBJECTIVE

Both bypass surgery and endovascular treatment are well-recognized interventions for the treatment of peripheral artery disease; however, the effect of failed endovascular treatment on subsequent surgeries remains controversial. A systematic review was conducted to compare the outcomes of primary bypass and bypass surgery after endovascular treatment.

METHODS

Three academic databases (Embase, PubMed, and Scopus) were searched from their inception to August 2022. Two independent investigators searched for studies that reported the outcomes of primary bypass surgery and bypass surgery after endovascular treatment in patients with peripheral artery disease. Abstracts and full-text studies were screened independently using duplicate data abstraction. Dichotomous outcome measures were reported using a random-effects model to generate a summary odds ratio (OR) and 95% confidence interval (CI). The risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

Seventeen retrospective observational studies were selected from 3911 articles and included 8064 patients, 6252 of whom underwent primary bypass surgery and 1812 underwent bypass surgery after endovascular treatment. The mean age was 69.0 years and 61.2% (n = 4938) were male. For perioperative outcomes, the 30-day results showed no difference in mortality (OR, 0.76; 95% CI, 0.53-1.10), or amputation (OR, 0.89; 95% CI, 0.67-1.20). For short- to mid-term outcomes, primary patency did not differ at 6 months (OR, 0.98; 95% CI, 0.81-1.19), 1 year (OR, 1.12; 95% CI, 0.97-1.30), or 2 years (OR, 1.17; 95% CI, 0.85-1.61) follow-up. Amputation-free survival did not differ at 6 months (OR, 1.03; 95% CI, 0.82-1.30), 1 year (OR, 1.09; 95% CI, 0.89-1.32), 2 years (OR, 1.18; 95% CI, 0.93-1.50), or 3 years (OR, 1.09; 95% CI, 0.84-1.40) of follow-up. No significant difference was found in overall survival or second patency.

CONCLUSIONS

This meta-analysis of retrospective, nonrandomized, observational studies suggests that prior endovascular treatment of lower extremity arterial disease does not result in worse perioperative, short-term, or mid-term clinical outcomes of subsequent infrainguinal bypass surgery compared with patients without prior endovascular treatment.

Efficacy and safety of iliofemoral bypass using arm veins as an alternative conduit for chronic limb-threatening ischemia

OBJECTIVE

The use of basilic vein in iliofemoral revascularizations was previously described in the literature as an autologous option for the treatment of vascular prosthesis infection and as a primary conduit in patients at high risk of infectious surgical complications. However, the publications available include several different indications and are limited to case reports. Therefore, the aim of this study was to evaluate the outcomes of the use of arm veins as a safe and effective autologous alternative for iliofemoral reconstruction in patients with chronic limb-threatening ischemia (CLTI) and at high risk of prosthesis infection.

METHODS

We performed a multicenter, retrospective cohort study with 53 consecutive iliofemoral bypasses using arm veins as an alternative conduit. The procedures were performed between November 2013 and November 2021, exclusively for patients with CLTI classified as TASC aortoiliac C or D with increased risk of postoperative surgical infection. Demographic, clinical variables, and outcomes were collected from a prospective database. Main endpoints were amputation-free survival (AFS) and major adverse cardiovascular events. Secondary endpoints included primary and secondary patencies and overall survival. Cox regression analysis was used to identify the predictors of AFS. Postoperative surgical complications and 30-day mortality were also assessed.

RESULTS

The mean age was 64.2 ± 8.4 years, with a predominance of male gender. The median follow-up period was 615 days. All patients had CLTI, with a predominance of tissue loss (n = 51; 96.2%) and a median ankle-brachial index of 0.28. The basilic vein was utilized in most procedures (69.8%). Thirty-day major adverse cardiovascular events occurred in five cases (9.4%), and the 30-day mortality rate was 3.8%. The AFS, primary patency, secondary patency, and overall survival in 720 days were 71%, 72%, 89%, and 75%, respectively. Cox regression analysis revealed no association between the variables analyzed for AFS. There was no graft late infection nor pseudoaneurysmal degeneration.

CONCLUSIONS

Iliofemoral bypass using arm veins as an autologous conduit proved to be an effective and safe procedure with low incidence of postoperative cardiovascular complications and high rates of AFS in patients with CLTI. Also, this suggests that arm veins can be an interesting and suitable autologous alternative conduit for iliofemoral reconstructions, especially in cases in which a prosthesis should be avoided or when it is not available.

Long-Term Results of Below-The-Knee Bypass Using a Prosthetic Graft with a Distal Arteriovenous Fistula Interposition

Surgical bypass is the gold standard treatment in patients affected by chronic limb-threatening ischemia in advanced GLASS stages, according to the Global Vascular Guidelines. For patients in whom an autologous graft is not available, a prosthesis could be used with the adjunct of a distal arteriovenous fistula interposition. The aim of this study was to examine the long-term results of below-the-knee surgical revascularization using a prosthesis with the distal adjunct mentioned above. From 2010 to 2020, we performed 159 lower limb below-the-knee surgical revascularizations using a prosthesis with the creation of an arteriovenous fistula interposition on the distal anastomosis. The GLASS stage was 3 in 100% of patients. The primary patency rates were as follows: 86.7% at 1 year, 57.2% at 3 years, and 12.6% at 5 years. The graft thrombosis rates were 17.4% at 1 year, 42.1% at 3 years, and 64.5% at 5 years. The amputation-free survival rates were 79% at 1 year, 76% at 3 years, and 64% at 5 years. PTFE prosthetic bypass for below-the-knee arteries using an arteriovenous fistula interposition is a good solution in patients without an autologous conduit. This technique offers reasonable graft patency and limb salvage rates.

Polytetrafluorethylene (PTFE) vs. Polyester (Dacron®) Grafts in Critical Limb Ischemia Salvage

BACKGROUND

Critical ischemia of the lower limbs refers to the last stages of peripheral arterial disease. It is characterized by resting discomfort or trophic disorders such as ulceration, skin necrosis, or gangrene in the lower limbs. Critical ischemia corresponds to Leriche-Fontaine (LF) stages III-IV and Rutherford stages 4-6. The purpose of this study was to observe the patency and postoperative complications of patients who have had infra-inguinal surgical revascularization and compare the results based on the kind of graft utilized.

METHODS

The present study was designed as an observational retrospective cohort study, including all patients from 2018 to 2019 diagnosed with severe ischemia of the lower limbs who were hospitalized at the Vascular Surgery Clinic of the County Emergency Clinical Hospital of Targu Mures.

RESULTS

Patients with a polytetrafluoroethylene (PTFE) graft had a higher incidence of chronic obstructive pulmonary disease (p = 0.01), stage III LF (70.41% vs. 55.29%), p = 0.03), and a lower incidence of stage IV LF (29.95% vs. 44.71%, p = 0.03). As for complications, the PTFE group showed a lower incidence of bypass thrombosis (29.59% vs. 44.71%; p = 0.03) and graft infection (9.18% vs. 21.18%; p = 0.02), but no statistical significance in the event of bleeding (p = 0.40). Regarding the outcomes, no statistical significance was seen for below-the-knee amputations or death. However, the PTFE group had a lower incidence of above-the-knee amputations (11.22% vs. 24.71%; p = 0.01). At multivariate analysis, the PTFE graft is an independent predictor of primary patency at 6, 12, and 24 months (OR: 2.15, p = 0.02; OR: 1.84, p = 0.04; and OR: 1.89, p = 0.03), as well as a protective factor against bypass thrombosis (OR: 0.52; p = 0.03), graft infection (OR: 0.37; p = 0.02), and above-the-knee amputation (OR: 0.38; p = 0.01).; Conclusions: According to this study's findings, there were minor differences regarding the long-term patency, bypass thrombosis, graft infections, and above-the-knee amputations. In addition, the PTFE graft group had a higher incidence of primary patency at 6, 12, and 24 months, as well as a lower incidence of bypass thrombosis, graft infection, and above-the-knee amputations.

Is open surgery still the first line of treatment for long femoropopliteal lesions?

INTRODUCTION

Treatment of long femoropopliteal lesions remains a challenge for vascular physicians as patients often present with multilevel complex pathologies and consequently face a high amputation risk and associated mortality. This review aimed to assess the current state of optimal revascularizations for the treatment of long femoropopliteal lesions.

EVIDENCE ACQUISITION

An online literature research of medical databases for original articles and review articles on open and endovascular revascularization of femoropopliteal lesions was conducted using mesh terms.

EVIDENCE SYNTHESIS

There has been an accumulation of evidence over the last years that endovascular treatment is a feasible and enduring alternative to open surgery for treatment of long femoropopliteal lesions if the lesions are restricted to the superficial femoral artery. But when disease extends to the infragenual level venous bypass remains superior with regards to long-term patency, clinical improvement and limb-salvage.

CONCLUSIONS

While the role of venous bypass as a first-line treatment might be declining, especially in frail patients or claudicants, the superior clinical improvement and amputation-free survival highlighted in several trials, demonstrate the relevance of bypass surgery. More randomized clinical trials are needed to verify the non-inferiority of endovascular treatment options to open surgery, especially when arterial disease extends below the knee.

Supera stent implantation for the treatment of isolated popliteal artery disease systematic review and evaluation of current endovascular strategies

<b>Introduction:</b> The anatomical location of the popliteal artery is one of the greatest challenges for percutaneous interventions. The biomechanical attributes of the vessel lead to higher rates of restenosis, stent fracture, and occlusion. Some surgeons consider the popliteal artery as a no stenting zone. Many specialists favor percutaneous transluminal angioplasty to be the first line of endovascular treatment in the popliteal artery with bail-out stent implantation if the results are suboptimal. The Supera peripheral stent system is a novel stent that has been manufactured with a high degree of flexibility and supposedly might be appropriate for implantation in the popliteal artery. </br></br> <b>Aim:</b> Evaluation of the performance of Supera stent in isolated popliteal artery disease in comparison to other methods of treatment. </br></br> <b>Methods:</b> As many as 92 articles were found in the databases and after full-text review, 4 studies matched the inclusion criteria and were evaluated. </br></br> <b>Results:</b> Primary patency rates of Supera implantation in an isolated popliteal artery at 12 months ranged from 68% to 90%. In all four studies, no stent fractures were observed. Only one study provided longer follow-up than 12 months and evaluated the performance of the Supera stent 36 months after implantation. </br></br> <b>Conclusion:</b> In conclusion, mentioned studies show promising and superior to other stent patency rates of the Supera stent regarding popliteal artery lesions. What is more, no stent fracture is promising regarding longer follow-up. However, more studies with longer follow-ups and direct comparison to other methods are required to fully evaluate Supera's performance in the popliteal artery.

Fresh cold-stored vascular allografts in subgenicular location: Our experience with rescue endovascular techniques

OBJECTIVE

Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. CLI is associated with high rates of morbidity and mortality and a high risk of limb amputation. In the absence of appropriate autologous grafts, unsuitability of prosthetic bypasses and endovascular methods, fresh cold-stored venous allografts is an option. Endovascular interventional methods are essential methods for maintaining primary and secondary patency.

METHODS

A single-centre retrospective analysis of 82 surgical revascularizations using allogeneic vascular grafts and rescue endovascular techniques restoring and maintaining the patency of these allogeneic revascularizations in the period between 7/2005 and 7/2021.

RESULT

We have performed 82 allogeneic revascularizations in 75 patients (52 reconstructions in men /63.4%/, 30 reconstructions in women /36.6%/). The median age of patients was 68 years (49 min, 87 max). We subsequently had to intervene a total of 26 bypasses. We intervened in 30 acute occluded allogeneic bypass grafts and 9 failing stenotic bypass grafts. We performed 52 angiographies. The success rate of rescue endovascular procedures in primary allogeneic reconstruction with distal anastomosis to the popliteal artery is statistically significant (p <0.02) compared to procedures with distal anastomosis to the tibial and pedal bed. The cumulative patency (primary at time) of allogeneic reconstructions in our group was 89% after 1 month, 51.9% after 12 months, 24.2% after 3 years, 9.8% after 5 years. Limb salvage was 72.6% in 1 year, 53% in 3 years, 36.5% in 5 years, respectively.

CONCLUSION

Cold-stored venous allografts may be used for performing below-the-knee revascularization for CLI with acceptable results despite poor long-term patency. Rescue endovascular techniques are an essential method for restoring or maintaining the patency of these reconstructions. These techniques have a high success rate and no other alternative.

Ex Vivo and In Vivo Analysis of a Novel Porcine Aortic Patch for Vascular Reconstruction

(1) Background: The aim of the present study was the biocompatibility analysis of a novel xenogeneic vascular graft material (PAP) based on native collagen won from porcine aorta using the subcutaneous implantation model up to 120 days post implantationem. As a control, an already commercially available collagen-based vessel graft (XenoSure®) based on bovine pericardium was used. Another focus was to analyze the (ultra-) structure and the purification effort. (2) Methods: Established methodologies such as the histological material analysis and the conduct of the subcutaneous implantation model in Wistar rats were applied. Moreover, established methods combining histological, immunohistochemical, and histomorphometrical procedures were applied to analyze the tissue reactions to the vessel graft materials, including the induction of pro- and anti-inflammatory macrophages to test the immune response. (3) Results: The results showed that the PAP implants induced a special cellular infiltration and host tissue integration based on its three different parts based on the different layers of the donor tissue. Thereby, these material parts induced a vascularization pattern that branches to all parts of the graft and altogether a balanced immune tissue reaction in contrast to the control material. (4) Conclusions: PAP implants seemed to be advantageous in many aspects: (i) cellular infiltration and host tissue integration, (ii) vascularization pattern that branches to all parts of the graft, and (iii) balanced immune tissue reaction that can result in less scar tissue and enhanced integrative healing patterns. Moreover, the unique trans-implant vascularization can provide unprecedented anti-infection properties that can avoid material-related bacterial infections.

A Propensity-Matched Analysis of Endovascular Intervention versus Open Nonautologous Bypass as Initial Therapy in Patients with Chronic Limb-Threatening Ischemia

OBJECTIVES

Endovascular therapies are increasingly used in patients with complex multilevel disease and chronic limb-threatening ischemia (CLTI). Infrageniculate bypass with autologous vein conduit is considered the gold standard in these patients. However, many patients often lack optimal saphenous vein, leading to the use of nonautologous prosthetic conduit. We compared limb salvage and survival rates for patients with CLTI undergoing first time revascularization with either open nonautologous conduit or endovascular intervention.

METHODS

We retrospectively reviewed consecutive patients undergoing first time endovascular or open surgical revascularization at our institution between 2009 and 2016. Patients were divided into endovascular intervention or open bypass with nonautologous conduit (NAC) cohorts. Primary endpoints were amputation-free survival (AFS), freedom from reintervention, primary patency, and overall survival. Propensity scoring was used to construct matched cohorts. Outcomes were evaluated using Kaplan-Meier and Cox Proportional Hazards models.

RESULTS

A total of 125 revascularizations were identified. There were 65 endovascular interventions and 60 NAC bypasses. In unmatched analysis, there was an elevated risk of perioperative MI (7% vs. 0%, P = 0.05) and amputation (10% vs. 2%, P = 0.04) for the NAC groups compared to the endovascular group. In matched analysis, endovascular patients had a lower incidence of 30-day amputation (1.5% vs. 10% P = 0.04) and length of stay (median days, 1 vs. 9, P < 0.01) compared to the open cohort. While not statistically significant, the endovascular group trended towards increased rates of two-year AFS (76% vs. 65%, P = 0.07) compared to the NAC group. There was no significant difference in overall survival when the endovascular cohort was compared to NAC (85% vs. 77%, P = 0.29) patients. In matched Cox analysis, nonautologous conduit use was associated with an increased risk of limb loss (HR 2.03, 95% CI 0.94-4.38, P = 0.07) compared to endovascular revascularization.

CONCLUSIONS

An "endovascular first" approach offers favorable perioperative outcomes and comparable AFS compared to NAC and may be preferable when autologous conduit is unavailable.

Inframalleolar bypass for chronic limb-threatening ischemia

The aims of this study were to analyze the results of inframalleolar bypass for chronic limb-threatening ischemia (CLTI) and to identify outcome-predicting factors. All consecutive patients undergoing inframalleolar bypass for CLTI between 2015 and 2018 were included in this retrospective, single-center study. Outflow artery was the most proximal patent vessel segment in continuity with inframalleolar arteries. Bypasses originating from the popliteal artery were defined as 'short bypasses'. Sixty patients underwent inframalleolar bypass, with four patients undergoing bilateral procedures, making a total of 64 limbs included. The mean age was 73 ± 14 and 52 (81%) were male. The great saphenous vein was the preferred conduit (n = 58, 91%), in a devalvulated fashion (n = 56, 88%). Superficial femoral artery was the most common inflow artery for 'long' grafts (n = 22, 34%), while popliteal artery was the inflow artery for all 'short' grafts (n = 25, 39%). Dorsalis pedis artery was chosen as an outflow artery in 41 patients (63%). Median follow-up was 21 months. Two-year primary and secondary patency, limb salvage, amputation-free survival, and overall survival rates were 67 ± 6%, 88 ± 4%, 84 ± 4%, 72 ± 6%, and 85 ± 4%, respectively. At multivariate analysis, dialysis was an independent predictor for poor primary patency (HR, 4.6; 95% CI, 1.62-13.05; p = 0.004), whereas a short bypass was independently associated with an increased primary patency (HR, 0.3; 95% CI, 0.10-0.89; p = 0.03). In conclusion, bypass grafting to the inframalleolar arteries resulted in good patency rates, limb salvage and overall survival. Dialysis patients had lower primary patency but still had good limb salvage and survival. Short bypass was a predictor of improved primary patency.

Comparison of Long Term Outcomes After Endovascular Treatment Versus Bypass Surgery in Chronic Limb Threatening Ischaemia Patients with Long Femoropopliteal Lesions

OBJECTIVE

There are currently two treatments available for patients with chronic limb threatening ischaemia (CLTI): open surgical bypass (OSB) and percutaneous transluminal angioplasty with/without stenting (PTA/S). The aim of this study was to compare short and long term outcomes between PTA/S and OSB in CLTI patients with long (GLASS grade III and IV) femoropopliteal disease.

METHODS

This was a two centre retrospective study including all consecutive patients with CLTI undergoing first time lower extremity intervention at two distinct vascular surgical centres. Between 1 January 2012 and 1 January 2018, 1 545 CLTI consecutive limbs were treated for femoropopliteal GLASS grade III and IV lesions at two vascular surgical centres. Using covariables from baseline and angiographic characteristics, a propensity score was calculated for each limb. Thus, comparable patient cohorts (235 in PTA/S and 235 in OSB group) were identified for further analysis. The primary outcomes were freedom from re-intervention in the treated extremity and major amputation. Secondary outcomes were all hospital complications among the two patient groups.

RESULTS

Total overall complication rates were significantly higher in the OSB group (20.42% vs. 5.96%, p < .001), especially wound infection/seroma rate that required prolonged hospitalisation and further treatment (7.65% vs. 0%, p < .001). After the median follow up of 61 months, re-intervention rates were significantly higher in the PTA/S group (log rank test, 44.68% vs. 29.79%, p = .002), but there was no significant difference in terms of major amputation rates between the two group of patients (log rank test, PTA/S 27.23% vs. OSB 22.13%, p = .17).

CONCLUSION

Bypass surgery seems to be superior to PTA/S for GLASS grade III and IV femoropopliteal lesions in patients with CLTI in terms of long term re-intervention rates, but with considerably higher rates of post-operative complications. A larger cohort of patients in currently ongoing randomised trials, as well as prospective cohort studies are necessary to confirm these findings.

Dynamic Luminal Topography: A Potential Strategy to Prevent Vascular Graft Thrombosis

AIM

Biologic interfaces play important roles in tissue function. The vascular lumen-blood interface represents a surface where dynamic interactions between the endothelium and circulating blood cells are critical in preventing thrombosis. The arterial lumen possesses a uniform wrinkled surface determined by the underlying internal elastic lamina. The function of this structure is not known, but computational analyses of artificial surfaces with dynamic topography, oscillating between smooth and wrinkled configurations, support the ability of this surface structure to shed adherent material (Genzer and Groenewold, 2006; Bixler and Bhushan, 2012; Li et al., 2014). We hypothesized that incorporating a luminal surface capable of cyclical wrinkling/flattening during the cardiac cycle into vascular graft technology may represent a novel mechanism of resisting platelet adhesion and thrombosis.

METHODS AND RESULTS

Bilayer silicone grafts possessing luminal corrugations that cyclically wrinkle and flatten during pulsatile flow were fabricated based on material strain mismatch. When placed into a pulsatile flow circuit with activated platelets, these grafts exhibited significantly reduced platelet deposition compared to grafts with smooth luminal surfaces. Constrained wrinkled grafts with static topography during pulsatile flow were more susceptible to platelet accumulation than dynamic wrinkled grafts and behaved similar to the smooth grafts under pulsatile flow. Wrinkled grafts under continuous flow conditions also exhibited marked increases in platelet accumulation.

CONCLUSION

These findings provide evidence that grafts with dynamic luminal topography resist platelet accumulation and support the application of this structure in vascular graft technology to improve the performance of prosthetic grafts. They also suggest that this corrugated structure in arteries may represent an inherent, self-cleaning mechanism in the vasculature.

Current Therapeutic Strategies in Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are the fastest growing chronic complication of diabetes mellitus, with more than 400 million people diagnosed globally, and the condition is responsible for lower extremity amputation in 85% of people affected, leading to high-cost hospital care and increased mortality risk. Neuropathy and peripheral arterial disease trigger deformities or trauma, and aggravating factors such as infection and edema are the etiological factors for the development of DFUs. DFUs require identifying the etiology and assessing the co-morbidities to provide the correct therapeutic approach, essential to reducing lower-extremity amputation risk. This review focuses on the current treatment strategies for DFUs with a special emphasis on tissue engineering techniques and regenerative medicine that collectively target all components of chronic wound pathology.

Active wrinkles to drive self-cleaning: A strategy for anti-thrombotic surfaces for vascular grafts

The inner surfaces of arteries and veins are naturally anti-thrombogenic, whereas synthetic materials placed in blood contact commonly experience thrombotic deposition that can lead to device failure or clinical complications. Presented here is a bioinspired strategy for self-cleaning anti-thrombotic surfaces using actuating surface topography. As a first test, wrinkled polydimethylsiloxane planar surfaces are constructed that can repeatedly transition between smooth and wrinkled states. When placed in contact with blood, these surfaces display markedly less platelet deposition than control samples. Second, for the specific application of prosthetic vascular grafts, the potential of using pulse pressure, i.e. the continual variation of blood pressure between systole and diastole, to drive topographic actuation was investigated. Soft cylindrical tubes with a luminal surface that transitioned between smooth and wrinkled states were constructed. Upon exposure to blood under continual pressure pulsation, these cylindrical tubes also showed reduced platelet deposition versus control samples under the same fluctuating pressure conditions. In both planar and cylindrical cases, significant reductions in thrombotic deposition were observed, even when the wrinkles had wavelengths of several tens of μm, far larger than individual platelets. We speculate that the observed thrombo-resistance behavior is attributable to a biofilm delamination process in which the bending energy within the biofilm overcomes interfacial adhesion. This novel strategy to reduce thrombotic deposition may be applicable to several types of medical devices placed into the circulatory system, particularly vascular grafts.

A systematic review of isolated radial artery harvesting as a conduit for lower limb bypass grafting

BACKGROUND

Whilst autologous vein conduits have been heralded as the first-line approach for patients undergoing lower limb bypass grafting procedures, patients with peripheral arterial occlusive disease may have exhausted venous options given prior use for cardiac surgery, varicose vein surgery, or lower limb revascularization. Hence, the use of a radial artery graft may serve as a viable alternative.

METHODS

The systematic review was performed in accordance to the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. An electronic search was performed on the following databases: Medline (via PubMed); EMBASE; Cochrane library to search for relevant publications. A narrative analysis was conducted.

RESULTS

Four publications were included in this review including two retrospective cohort studies, one case series, and one case report, with a total of 43 patients. The most common indication for lower limb bypass grafting was critical limb ischemia, and the radial artery was chosen as graft conduit, most commonly due to the absence of suitable arm or leg vein. There was one case of 30-day mortality and 11 reinterventions.

CONCLUSION

Despite the encouraging results, the paucity of high-quality studies prevents the establishment of any firm conclusion. This warrants the need for appropriately conducted randomized controlled trials to compare the radial artery graft to autologous vein grafts and prosthetic grafts for lower limb bypass grafting.

Examples of dramatic failures and their effectiveness in modern surgical disciplines: can we learn from our mistakes?

Innovation can be variably defined, but when applied to healthcare is often considered to be the introduction of something new, whether an idea, method or device, into an unfilled void or needy environment. Despite the introduction of many positive surgical subspecialty altering concepts/devices however, epic failures are not uncommon. These failures can be dramatic in regards to both their human and economic costs. They can also be very public or more quiet in nature. As surgical leaders in our communities and advocates for patient safety and outcomes, it remains crucial that we meet new introductions in technology and patient care with a measured level of curiosity, skepticism and science-based conclusions. The aim of an expert committee was to identify the most dominant failures in technological innovation and/or dogmatic clinical beliefs within each major surgical subspecialty. In summary, this effort was pursued to highlight the past failures and remind surgeons to remain vigilant and appropriately skeptical with regard to the introduction of new innovations and clinical beliefs within our craft.

Critical limb ischemia: current challenges and future prospects

Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. It is defined by the presence of chronic ischemic rest pain, ulceration or gangrene attributable to the occlusion of peripheral arterial vessels. It is associated with a high risk of major amputation, cardiovascular events and death. In this review, we presented a complete overview about physiopathology, diagnosis and holistic management of CLI. Revascularization is the first-line treatment, but several challenging cases are not treatable by conventional techniques. Unconventional techniques for the treatment of complex below-the-knee arterial disease are described. Furthermore, the state-of-the-art on gene and cell therapy for the treatment of no-option patients is reported.

Graft type for femoro-popliteal bypass surgery

BACKGROUND

Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves grafts using autologous vein, polytetrafluoroethylene (PTFE) or Dacron as a bypass conduit. This is the second update of a Cochrane review first published in 1999 and last updated in 2010.

OBJECTIVES

To assess the effects of bypass graft type in the treatment of stenosis or occlusion of the femoro-popliteal arterial segment, for above- and below-knee femoro-popliteal bypass grafts.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Vascular Specialised Register (13 March 2017) and CENTRAL (2017, Issue 2). Trial registries were also searched.

SELECTION CRITERIA

We included randomised trials comparing at least two different types of femoro-popliteal grafts for arterial reconstruction in patients with femoro-popliteal ischaemia. Randomised controlled trials comparing bypass grafting to angioplasty or to other interventions were not included.

DATA COLLECTION AND ANALYSIS

Both review authors (GKA and CPT) independently screened studies, extracted data, assessed trials for risk of bias and graded the quality of the evidence using GRADE criteria.

MAIN RESULTS

We included nineteen randomised controlled trials, with a total of 3123 patients (2547 above-knee, 576 below-knee bypass surgery). In total, nine graft types were compared (autologous vein, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), polyurethane (PUR), Dacron and heparin bonded Dacron (HBD); FUSION BIOLINE and Dacron with external support). Studies differed in which graft types they compared and follow-up ranged from six months to 10 years.Above-knee bypassFor above-knee bypass, there was moderate-quality evidence that autologous vein grafts improve primary patency compared to prosthetic grafts by 60 months (Peto odds ratio (OR) 0.47, 95% confidence interval (CI) 0.28 to 0.80; 3 studies, 269 limbs; P = 0.005). We found low-quality evidence to suggest that this benefit translated to improved secondary patency by 60 months (Peto OR 0.41, 95% CI 0.22 to 0.74; 2 studies, 176 limbs; P = 0.003).We found no clear difference between Dacron and PTFE graft types for primary patency by 60 months (Peto OR 1.67, 95% CI 0.96 to 2.90; 2 studies, 247 limbs; low-quality evidence). We found low-quality evidence that Dacron grafts improved secondary patency over PTFE by 24 months (Peto OR 1.54, 95% CI 1.04 to 2.28; 2 studies, 528 limbs; P = 0.03), an effect which continued to 60 months in the single trial reporting this timepoint (Peto OR 2.43, 95% CI 1.31 to 4.53; 167 limbs; P = 0.005).Externally supported prosthetic grafts had inferior primary patency at 24 months when compared to unsupported prosthetic grafts (Peto OR 2.08, 95% CI 1.29 to 3.35; 2 studies, 270 limbs; P = 0.003). Secondary patency was similarly affected in the single trial reporting this outcome (Peto OR 2.25, 95% CI 1.24 to 4.07; 236 limbs; P = 0.008). No data were available for 60 months follow-up.HUV showed benefits in primary patency over PTFE at 24 months (Peto OR 4.80, 95% CI 1.76 to 13.06; 82 limbs; P = 0.002). This benefit was still seen at 60 months (Peto OR 3.75, 95% CI 1.46 to 9.62; 69 limbs; P = 0.006), but this was only compared in one trial. Results were similar for secondary patency at 24 months (Peto OR 4.01, 95% CI 1.44 to 11.17; 93 limbs) and at 60 months (Peto OR 3.87, 95% CI 1.65 to 9.05; 93 limbs).We found HBD to be superior to PTFE for primary patency at 60 months for above-knee bypass, but these results were based on a single trial (Peto OR 0.38, 95% CI 0.20 to 0.72; 146 limbs; very low-quality evidence). There was no difference in primary patency between HBD and HUV for above-knee bypass in the one small study which reported this outcome.We found only one small trial studying PUR and it showed very poor primary and secondary patency rates which were inferior to Dacron at all time points.Below-knee bypassFor bypass below the knee, we found no graft type to be superior to any other in terms of primary patency, though one trial showed improved secondary patency of HUV over PTFE at all time points to 24 months (Peto OR 3.40, 95% CI 1.45 to 7.97; 88 limbs; P = 0.005).One study compared PTFE alone to PTFE with vein cuff; very low-quality evidence indicates no effect to either primary or secondary patency at 24 months (Peto OR 1.08, 95% CI 0.58 to 2.01; 182 limbs; 2 studies; P = 0.80 and Peto OR 1.22, 95% CI 0.67 to 2.23; 181 limbs; 2 studies; P = 0.51 respectively)Limited data were available for limb survival, and those studies reporting on this outcome showed no clear difference between graft types for this outcome. Antiplatelet and anticoagulant protocols varied extensively between trials, and in some cases within trials.The overall quality of the evidence ranged from very low to moderate. Issues which affected the quality of the evidence included differences in the design of the trials, and differences in the types of grafts they compared. These differences meant we were often only able to combine and analyse small numbers of participants and this resulted in uncertainty over the true effects of the graft type used.

AUTHORS' CONCLUSIONS

There was moderate-quality evidence of improved long-term (60 months) primary patency for autologous vein grafts when compared to prosthetic materials for above-knee bypasses. In the long term (two to five years) there was low-quality evidence that Dacron confers a small secondary patency benefit over PTFE for above-knee bypass. Only very low-quality data exist on below-knee bypasses, so we are uncertain which graft type is best. Further randomised data are needed to ascertain whether this information translates into an improvement in limb survival.

Clinical Outcomes after Isolated Infrapopliteal Revascularization in Hemodialysis Patients with Critical Limb Ischemia: Endovascular Therapy versus Bypass Surgery

AIM

To investigate the long-term clinical outcome of endovascular therapy (EVT) or bypass surgery in patients on hemodialysis (HD) with critical limb ischemia due to isolated infrapopliteal disease.

METHODS

We enrolled 254 consecutive HD patients successfully undergoing infrapopliteal revascularization by EVT (126 patients) and bypass surgery (128 patients). They were followed up for five years. Amputation-free survival (AFS) and incidence of any re-intervention were evaluated. A propensity score from all baseline variables was incorporated into Cox analysis.

RESULTS

In the EVT group, age was higher (p=0.039), diabetes and coronary artery disease were more frequent (p=0.004 and p=0.0052, respectively), and tissue loss was more rarely observed (p＜ 0.0001) than in the bypass group. During the follow-up period, 21 major amputations and 64 deaths occurred. The propensity score-adjusted AFS rate at 5 years was comparable between groups (61.0% in EVT group vs. 55.1% in the bypass group, adjusted hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.52-1.42, p=0.58). The adjusted survival rates were also similar between groups for amputation and all-cause mortality. However, freedom from any re-intervention was markedly lower in the EVT than in the bypass group (48.6% vs. 84.6%, adjusted-HR, 3.56, 95% CI 1.95-6.75, p＜ 0.0001).

CONCLUSIONS

The rate of AFS was broadly comparable between the two strategies, although compared with bypass surgery, EVT had much higher rates for re-intervention.

Chronic Nonatherosclerotic Occlusive Popliteal Artery Disease

BACKGROUND

The outcomes of revascularization of nonatherosclerotic occlusive popliteal artery disease are unknown. Therefore, the objective of this study was to analyze the outcomes of recanalization of nonatherosclerotic occlusive popliteal artery disease, the results of which would be useful in creating surgical strategies for such cases.

METHODS

From January 2000 to December 2015, a total of 22 patients with nonatherosclerotic occlusive popliteal artery disease underwent open surgical repair. We retrospectively analyzed the data of these patients. Thrombectomy with angioplasty on the occluded popliteal artery, graft interposition, and bypass surgery were conducted for revascularization of the affected region. We analyzed the overall primary patency rate, type of graft, and surgical approach. Furthermore, we compared the primary patency rate after surgical treatment.

RESULTS

Of 22 patients, 3 (13.6%) had cystic adventitial disease, 16 (72.7%) had popliteal artery entrapment syndrome, and 3 (13.6%) were diagnosed as having thromboangiitis obliterans. Five patients (22.7%) underwent thrombectomy with patch angioplasty, 8 (36.3%) underwent bypass surgery, and 9 (40.9%) underwent graft interposition of the popliteal artery. All graft interpositions and thrombectomies with patch angioplasty were performed through a posterior approach, whereas all bypass surgeries were performed through a medial approach except in 1 case. The mean follow-up period was 54.95 ± 42.99 months. The overall primary patency rate at 1, 3, and 10 years was 100%, 86.9%, and 69.5%, respectively. In the bypass group, the primary patency rate at 1, 3, and 10 years was 100%, 66.7%, and 44.4%, respectively. In the other groups, the primary patency rate was 100% during the follow-up period. The difference in primary patency rate was statistically significant (P ≤ 0.05).

CONCLUSIONS

The result of surgical treatment for nonatherosclerotic occlusive popliteal artery disease was better than that of atherosclerotic popliteal artery disease. Direct popliteal artery reconstruction, such as graft interposition or thrombectomy with patch angioplasty, showed better short- and long-term patency than did bypass surgery.

Alternative conduit for infrageniculate bypass in patients with critical limb ischemia

BACKGROUND

Autologous great saphenous vein (GSV) has always been considered the gold standard conduit for infrainguinal revascularization. When GSV is inadequate or unavailable, alternative conduits have been used. In this study, we compared modern outcomes of different conduit types used in lower extremity bypass (LEB) for patients with critical limb ischemia (CLI).

METHODS

The Vascular Study Group of New England database (2003-2014) was queried for patients who underwent infrageniculate bypass originating from the femoral arteries. Conduit types were categorized as single-segment GSV, alternative autologous conduit (AAC), and nonautologous conduit (NAC). Primary outcomes were 1-year freedom from major adverse limb event (MALE), MALE-free survival, and primary graft patency. Multivariable Cox regression was used to adjust for demographics and comorbidities.

RESULTS

LEB was performed in 2148 patients, of which 1125 were to below-knee popliteal (BK-Pop) and 1023 to infrapopliteal artery (IPA) targets. The baseline characteristics differed among the conduit groups: Patients in the GSV group were younger and had fewer comorbidities than in the AAC groups. Patients undergoing BK-Pop bypass with NAC had higher rates of postoperative myocardial infarction (7.1%) and postoperative (5.8%) and 1-year death (40.8%) than in those with GSV (3.1%, 2%, and 31.7%, respectively) and AAC (0%, 0%, and 25%, respectively). In multivariable analysis, conduit type did not make a difference in 1-year MALE, MALE-free survival, or primary graft patency for BK-Pop bypasses. For IPA bypasses, NAC use was associated with higher rates of postoperative (6.4%) and in-hospital death (4.5%) compared with GSV (2.5% and 1.4%, respectively) and AAC (2.9% and 1.9%, respectively). In adjusted analysis, NAC was associated with higher risk of MALE (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.03-2.20; P = .036) and primary patency loss (HR, 1.3; 95% CI, 0.91-1.89), and lower MALE-free survival (HR, 1.47; 95% CI, 1.03-2.09; P = .035) compared with GSV. There was no difference between the NAC and AAC groups.

CONCLUSIONS

Conduit type does not affect outcomes in BK-Pop bypass. In the absence of single-segment GSV, the use of AAC for IPA bypass does not appear to confer any additional benefit of MALE, MALE-free survival, or graft patency compared with prosthetic grafts at 1-year follow-up.

Infrainguinal open reconstruction: a review of surgical considerations and expected outcomes

Infrainguinal arterial occlusive disease can lead to potentially disabling and limb-threatening conditions. Revascularization may be indicated for claudication, rest pain, or tissue loss. Although endovascular interventions are becoming more prevalent, open surgeries such as endarterectomy and bypass are still needed and performed regularly. Open reconstruction has been associated with postoperative morbidity, both at the local and at the systemic levels. Local complications include surgical site infections (SSIs 0-5.3%), graft failure (12-60%), and amputation (5.7-27%), and more systemic issues include cardiac (2.6-18.4%), respiratory (2.5%), renal (4%), neurovascular (1.5%), and thromboembolic (0.2-1%) complications. While such outcomes present an additional challenge to the postoperative management of surgical patients, it may be possible to minimize their occurrence through careful risk stratification and preoperative assessment. Therefore, individualized selection of candidates for open repair requires weighing the need for intervention against the likelihood of adverse outcomes based on preoperative risk factors. This review provides an overview of open reconstruction, focusing on identifying the clinical indications for surgery and perioperative morbidity and mortality.

Results for primary bypass versus primary angioplasty/stent for lower extremity chronic limb-threatening ischemia

BACKGROUND

Long-term results comparing percutaneous transluminal angioplasty with or without stenting (PTA/S) and open surgical bypass for chronic limb-threatening ischemia (CLTI) in patients who have had no prior intervention are lacking.

METHODS

All patients undergoing a first-time lower extremity revascularization for CLTI by vascular surgeons at our institution from 2005 to 2014 were retrospectively reviewed. Outcomes included perioperative complications, wound healing, restenosis, primary patency, reintervention, major amputation, RAS events (ie, reintervention, major amputation, or stenosis), and mortality. Outcomes were evaluated using χ², Kaplan-Meier, and Cox regression analyses.

RESULTS

Of the 2869 total lower extremity revascularizations performed between 2005 and 2014, there were 1336 that fit our criteria of a first-time lower extremity intervention for CLTI (668 bypass procedures and 668 PTA/S procedures). Bypass patients were younger (71 vs 72 years; P = .02) and more often male (62% vs 56%; P < .02). Total mean hospital length of stay (LOS) was significantly longer after a first-time bypass (10 vs 8 days; P < .001), as were mean preoperative LOS (4 vs 3 days; P < .01) and postoperative LOS (7 vs 5 days; P < .001). There was no difference in perioperative mortality (3% vs 3%; P = .63). Surgical site infection occurred in 10% of bypass patients. Freedom from reintervention was significantly higher in patients undergoing a first-time bypass procedure (62% vs 52% at 3 years; P = .04), as was freedom from restenosis (61% vs 45% at 3 years; P < .001). Complete wound healing at 6-month follow-up was significantly better after an initial bypass (43% vs 36%; P < .01). A Cox regression model of all patients showed that reintervention was predicted by a first-time PTA/S (hazard ratio, 1.6; 95% confidence interval, 1.3-2.1) and both preoperative femoropopliteal TransAtlantic Inter-Society Consensus (TASC) C and TASC D lesions (2.0 [1.3-3.1] and 1.8 [1.3-2.7], respectively). Major amputation among all patients was predicted by an initial presentation of gangrene (2.5 [1.3-5.0]), dialysis dependence (1.9 [1.3-2.9]), diabetes (2.0 [1.1-3.8]), and preoperative femoropopliteal TASC D lesions (2.1 [1.1-4.0]) and was not predicted by procedure type.

CONCLUSIONS

In this retrospective analysis, bypass for the primary treatment of CLTI showed improved 6-month wound healing, higher freedom from restenosis, improved patency rates, significantly fewer reinterventions, and higher survival than PTA/S within 3 years; however, a bypass-first approach was associated with increased total hospital LOS and wound infection. Perioperative mortality and amputation rates were similar between procedure types.

Comparison of angioplasty and bypass surgery for critical limb ischaemia in patients with infrapopliteal peripheral artery disease

BACKGROUND

Both infrapopliteal (IP) bypass surgery and percutaneous transluminal angioplasty have been shown to be effective in patients with critical limb ischaemia (CLI). The most appropriate method of revascularization has yet to be established, as no randomized trials have been reported. The aim of this study was to compare the outcomes of patients with similar characteristics treated using either revascularization method.

METHODS

Consecutive patients undergoing IP bypass and IP angioplasty for CLI (Rutherford 4-6) at a single institution were compared following propensity score matching. The study endpoints were primary, assisted primary and secondary patency, and amputation-free survival at 12 months, calculated by Kaplan-Meier analysis.

RESULTS

Some 279 limbs in 243 patients were included in the study. The two groups differed significantly with respect to the incidence of diabetes (P = 0·024), estimated glomerular filtration rate (P = 0·006), total lesion length (P < 0·001) and Rutherford classification (P = 0·008). These factors were used to construct the propensity score model, which yielded a matched cohort of 125 legs in each group. Primary patency (54·4 versus 51·4 per cent; P = 0·014), assisted primary patency (77·5 versus 62·7 per cent; P = 0·003), secondary patency (84·4 versus 65·8 per cent; P < 0·001) and amputation-free survival (78·7 versus 74·1 per cent; P = 0·043) were significantly better after bypass than angioplasty. However, limb salvage was similar (90·4 versus 94·2 per cent; P = 0·161), and overall complications (36·0 versus 21·6 per cent; P = 0·041) as well as length of hospital stay (18(4-134) versus 5(0-110); P = 0·001) were worse in the surgical bypass group.

CONCLUSION

There was no difference in limb salvage rates, but patency and amputation-free survival rates were better 1 year after bypass surgery.

Adjunctive Uses of the Radial Artery for Emergency Infrapopliteal Bypass in Patients Presenting With Acute Limb-Threatening Ischemia

Although the radial artery has proven to be a reliable conduit for arterial bypass procedures in cardiac surgery, its use in lower extremity revascularization has been limited due to its length. In patients who have undergone multiple cardiovascular procedures, venous conduit options can be limited, and infrapopliteal bypass with prosthesis has been shown to yield poor patency rates. In this report, the authors describe 3 different uses of the radial artery in patients with acute limb-threatening ischemia in the redo setting, which resulted in limb salvage.

Infrainguinal Arterial Intervention: Is There a Role for an Atherectomy Device?

Excision of atheromatous plaque is an attractive option for the minimally invasive treatment of peripheral arterial disease. Approved for use in 2003, the SilverHawk Plaque Exicison System (FoxHollow Technologies, Redwood City, CA) is a catheter-based plaque excision device allowing percutaneous removal of atheromatous material. This device represents the most recent generation of atherectomy tools. Overall experience with plaque debulking in the peripheral arteries spans almost two decades, and understanding of the technique continues to evolve. This article reviews the technology, current practices, and data on plaque excision.

Crossing chronic total occlusions with the Ocelot system: the initial European experience

AIMS

The aim of the study was to determine the safety, efficacy and feasibility of a new chronic total occlusion (CTO) device using optical coherence tomography (OCT) technology, the Ocelot catheter (Avinger, Inc., Redwood City, CA, USA), for crossing of SFA CTOs following guidewire failure.

METHODS AND RESULTS

Prospective, multicentre, market preference testing. Thirty-three patients with confirmed CTO (99-100% stenosis by visual estimate) of their superficial femoral artery (SFA) were treated between September 28, 2011, and December 9, 2011, at three European centres. Ocelot crossed 94% (31/33) of CTOs, allowing guidewire placement in the distal true lumen. All (100%) lesions were treated without any major adverse safety events. Procedural time and contrast dose were significantly reduced (p<0.0001) when compared with a similar, non-OCT-guided CTO crossing device (Wildcat catheter; Avinger, Inc.). Overall physician feedback on the catheter performance was positive with an 87% average rating of excellent or good across seven categories. Performance ratings of Ocelot's OCT imaging guidance were consistently positive with an 86% average rating of excellent or good across five OCT categories.

CONCLUSIONS

The Ocelot catheter combines advanced CTO crossing technology with real-time OCT guidance. When compared with a similar non-OCT-guided catheter, crossing efficacy and safety profile improved. Total procedure time and contrast volumes were significantly reduced. The Ocelot is a safe, efficient and effective tool for crossing CTOs.

Treatment of Chronic Total Occlusions Using the Avinger Ocelot Crossing Catheter

Peripheral arterial disease is becoming more prevalent as the population ages. In addition, the severity of the disease seems to be progressing from simple narrowing of vessels to chronic total occlusions (CTOs). Treatment of CTOs of the infrainguinal peripheral arteries remains a challenge even for experienced endovascular specialists. Many crossing techniques have been described ranging from standard guidewire and catheter-based techniques including subintimal recanalization to specialized CTO crossing devices. One of the newest technologies, the Avinger Ocelot catheter (Avinger, Inc., Redwood City, CA), employs optical coherence tomography imaging on the tip of a rotating crossing catheter to allow visual confirmation of luminal passage. This article will review this new technology for crossing CTOs, review the results of the multicenter CONNECT II trial, and discuss the potential benefits of direct visualization while crossing occlusions.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries: A Supplement to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II): The TASC Steering Comittee(.)

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries: A Supplement to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II)

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

Direct Revascularization With the Angiosome Concept for Lower Limb Ischemia: A Systematic Review and Meta-Analysis

The angiosome concept provides practical information regarding the vascular anatomy of reconstructive and vascular surgery for the treatment of peripheral arterial occlusive disease and, particularly, critical lower limb ischemia.The aim of the study was to confirm the efficacy of direct revascularization with the angiosome concept (DR) for lower limb ischemia.Complementary manual searches were performed through the Pubmed, Cochrane Library, and EMBASE databases.We searched all randomized and nonrandomized studies (NRSs) comparing DR with indirect revascularization (IR) (without the angiosome concept) for lower limb ischemia. Only 9 nonrandomized controlled retrospective cohort studies were found and included. Trials published in any language were included.Primary endpoints were time to limb amputation and time to wound healing. Data extraction and trial quality assessment were performed by two authors independently. A third author was consulted for disagreements settlement and quality assurance.Five NRSs involving 779 lower limbs revealed that DR significantly improved the overall survival of limbs (hazard ratio [HR] 0.61; 95% confidence interval [CI] = 0.46-0.80; P < 0.001; I = 0%). In addition, DR significantly improved time to wound healing (HR 1.38; 95% CI = 1.13-1.69; P = 0.002; I = 0%, in 5 studies including 605 limbs).All included studies were retrospective comparative studies, and no consensus was obtained in describing wound conditions in the included studies.Our results suggested that treatment of lower limb ischemia using DR is more effective in salvaging limbs and healing wounds than IR is. Additional randomized controlled studies are necessary to confirm these results.

Arm veins versus contralateral greater saphenous veins for lower extremity bypass reconstruction: preliminary data of a randomized study

BACKGROUND

The aim of this randomized study was to determine whether arm vein (AV) or contralateral greater saphenous vein (CGSV) is the better alternative vein source for lower extremity bypass reconstruction.

METHODS

Consecutive patients with absent ipsilateral greater saphenous vein undergoing lower extremity revascularization were allocated to group A (AV bypass) or B (CGSV bypass).

RESULTS

From 6, 2010, to 11, 2013, 64 patients (32 each group) were randomized. In all, 29 of 93 patients had to be excluded for various reasons. Median age was 76 years vs. 71 years (P = 0.01) for group A and B patients. There were no statistically significant differences regarding gender, cardiovascular risk factors, redo bypass procedures (P = 0.77), below-knee bypass procedures (P = 0.61), median bypass length (P = 0.6), and median length of incision on ipsilateral leg to perform anastomoses (P = 0.2) between group A and B patients, respectively. Incisions for vein harvest were longer in group A (P = 0.003). Overall surgical site infections (SSIs, P = 1.0) and SSI from vein harvest (P = 1.0) were equally distributed. No patient was lost to follow-up (17 vs. 18 months, P = 0.74). There was no statistically significant difference regarding primary (P = 0.77) and secondary (P = 0.25) patency rates at 1 year (group A: 52% vs. group B: 54% and group A: 72% vs. group B: 61%) and at 2 years (52% vs. 48% and 64% vs. 61%), respectively. There were 4 vs. 6 major amputations (P = 0.23) and 5 vs. 2 deaths (P = 0.1) in groups A and B during follow-up.

CONCLUSIONS

Preliminary results suggest that both AV and CGSV may serve as a secondary vein bypass graft equally well.

Contemporary Management of Femoral Popliteal Revascularization

Symptomatic peripheral artery disease of the femoral popliteal segment can be treated by surgical and endovascular revascularization, but controversy exists about the best approach. Conventional approaches to revascularization have focused on lesion anatomy to decide on bypass versus endovascular treatment, but advances in endovascular therapy make an endovascular-first approach increasingly feasible-either as a single approach or as an adjunct to short-segment bypass (ie, hybrid procedure). In this review, we discuss the medical, endovascular, and surgical treatment of femoral popliteal revascularization with a special emphasis on advances in percutaneous therapy.

Endovascular-first approach is not associated with worse amputation-free survival in appropriately selected patients with critical limb ischemia

OBJECTIVE

Endovascular interventions for critical limb ischemia are associated with inferior limb salvage (LS) rates in most randomized trials and large series. This study examined the long-term outcomes of selective use of endovascular-first (endo-first) and open-first strategies in 302 patients from March 2007 to December 2010.

METHODS

Endo-first was selected if (1) the patient had short (5-cm to 7-cm occlusions or stenoses in crural vessels); (2) the disease in the superficial femoral artery was limited to TransAtlantic Inter-Society Consensus II A, B, or C; and (3) no impending limb loss. Endo-first was performed in 187 (62%), open-first in 105 (35%), and 10 (3%) had hybrid procedures.

RESULTS

The endo-first group was older, with more diabetes and tissue loss. Bypass was used more to infrapopliteal targets (70% vs 50%, P = .031). The 5-year mortality was similar (open, 48%; endo, 42%; P = .107). Secondary procedures (endo or open) were more common after open-first (open, 71 of 105 [68%] vs endo, 102 of 187 [55%]; P = .029). Compared with open-first, the 5-year LS rate for endo-first was 85% vs 83% (P = .586), and amputation-free survival (AFS) was 45% vs 50% (P = .785). Predictors of death were age >75 years (hazard ratio [HR], 3.3; 95% confidence interval [CI], 1.7-6.6; P = .0007), end-stage renal disease (ESRD) (HR, 3.4; 95% CI, 2.1-5.6; P < .0001), and prior stroke (HR, 1.6; 95% CI, 1.03-2.3; P = .036). Predictors of limb loss were ESRD (HR, 2.5; 95% CI, 1.2-5.4; P = .015) and below-the-knee intervention (P = .041). Predictors of worse AFS were older age (HR, 2.03; 95% CI, 1.13-3.7; P = .018), ESRD (HR, 3.2; 95% CI, 2.1-5.11; P < .0001), prior stroke (P = .0054), and gangrene (P = .024).

CONCLUSIONS

At 5 years, endo-first and open-first revascularization strategies had equivalent LS rates and AFS in patients with critical limb ischemia when properly selected. A patient-centered approach with close surveillance improves long-term outcomes for both open and endo approaches.

Long-term follow-up of last autogenous option arm vein bypass

BACKGROUND

The superiority of autogenous conduits in infrainguinal bypass surgery is well established. At our institution, arm vein is utilized as the last autogenous option for infrainguinal bypass surgery. The aim of this study was to review the long-term outcomes of last autogenous option arm vein bypass.

METHODS

All infrainguinal arm vein bypasses performed between 1997 and 2005 by The Queen Elizabeth Hospital vascular surgeons were identified. Patency, reintervention, limb salvage and survival were calculated using the Kaplan-Meier survival estimate method.

RESULTS

Thirty-eight arm vein bypasses were performed in 35 patients. Eighty-nine per cent were performed for critical limb ischaemia. Median follow-up was 58 months (range 2-121). Twelve-month primary, assisted primary and secondary patency rates were 52%, 73% and 76%, respectively. Three-year primary, assisted primary and secondary patency rates were 32%, 61% and 63%, respectively. Five-year primary, assisted primary and secondary patency rates were 21%, 47% and 49%, respectively. Patency was superior in single compared with spliced vein grafts (P < 0.05). Limb salvage rates at 1, 3 and 5 years were 94%, 87% and 76%, respectively. Patient survival at 1, 3 and 5 years was 92%, 68% and 49%, respectively.

DISCUSSION

Infrainguinal bypass surgery with arm vein can be performed safely with favourable patency and high rates of limb salvage. Secondary interventions to maintain patency are common and we recommend a vigilant surveillance programme to identify the threatened graft.

A cost-effectiveness analysis of infrainguinal bypass in the absence of great saphenous vein conduit

BACKGROUND

Good-quality great saphenous vein (GSV) is the preferred conduit for infrainguinal surgical revascularizations, but it is not available in all patients. We sought to identify the alternative conduit that would maximize cost-effectiveness in the context of infrapopliteal bypass for critical limb ischemia and nonhealing foot wounds.

METHODS

A Markov model was used to create a detailed simulation of 10-year outcomes in a hypothetical Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT) III-type patient cohort undergoing infrainguinal bypass for nonhealing foot wounds. The following management options were evaluated: (1) conservative therapy (local wound care, amputation as needed); (2) primary amputation; (3) bypass with autologous alternative vein (AAV), including arm or lesser saphenous vein; (4) bypass with GSV <3 mm in diameter; (5) bypass with polytetrafluoroethylene (PTFE); (6) cryopreserved venous allograft; and (7) cryopreserved arterial allograft. Estimates of 10-year total costs were incorporated into the model. Cost-effectiveness was measured in terms of incremental United States dollars per additional year of ambulation.

RESULTS

Bypass with AAV had the highest effectiveness as measured in median years of ambulation. After primary amputation, bypass with PTFE had the lowest total costs. With incremental cost-effectiveness ratios of $5325 and $21,228, bypass with PTFE or AAV appeared to be cost-effective alternatives to conservative therapy for nonhealing ischemic wounds. Primary amputation, GSV <3 mm, and allograft options were dominated (ie, more costly and less effective). Primary amputation was weakly dominated.

CONCLUSIONS

Bypass with PTFE or AAV appears to be a cost-effective option for the management of critical limb ischemia and nonhealing foot wounds when good-quality GSV is not available.