Comparison of initial hemodynamic response after endovascular therapy and open surgical bypass in patients with diabetes mellitus and critical limb ischemia

The Effect of Lower Limb Revascularization on Flow, Perfusion, and Systemic Endothelial Function: A Systematic Review

Peripheral arterial disease (PAD) is associated with reduced lower limb blood flow and tissue perfusion. The consequent reduction in vessel wall shear stress as well as ischemia-reperfusion injury has also been associated with systemic endothelial dysfunction and inflammation. We aimed to explore the impact of lower limb revascularization on (1) lower limb blood flow, (2) tissue perfusion, and (3) systemic endothelial function. We performed a systematic literature search using the MEDLINE, Embase, and Web of Science databases. Eligible studies measured changes in lower limb blood flow, perfusion, or systemic endothelial function following revascularization for the treatment of symptomatic PAD. We found 19 eligible studies, which were limited by considerable heterogeneity. Current evidence suggests that revascularization has a positive effect on flow, perfusion, and systemic endothelial dysfunction. Any changes may take a number of weeks to become apparent. There is a need for well-designed studies to explore the association between flow, perfusion, and endothelial dysfunction.

Limb-Based Patency After Surgical vs Endovascular Revascularization in Patients with Chronic Limb-Threatening Ischemia

PURPOSE

To determine whether limb-based patency (LBP) after infrainguinal revascularization for chronic limb-threatening ischemia (CLTI) is similar between bypass surgery and endovascular therapy (EVT).

MATERIALS AND METHODS

The database for the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) study was interrogated to identify 130 patients (mean age 73±8 years; 94 men) who underwent bypass surgery and 271 patients (mean age 74±10 years; 178 men) who underwent EVT alone. Skin perfusion pressure (SPP) and the ankle-brachial index (ABI) were measured before the procedure and at 0, 1, and 3 months after revascularization. The outcome measure was hemodynamically evaluated LBP (SPP ≥10 mm Hg or ABI ≥0.1) maintained over the first 3 months after treatment. Any reintervention or major amputation was regarded as loss of LBP. The associations between the revascularization strategy (bypass vs EVT) and between the preoperative characteristics and the study outcome (ie, SPP- or ABI-based LBP), were determined using generalized linear mixed models with a logit link function. Patency rates are presented with the 95% confidence interval (CI).

RESULTS

The bypass surgery group had a higher stage of limb severity (WIfI) and anatomic complexity (GLASS) than the EVT group, whereas the EVT group had a higher prevalence of heart failure. Both SPP- and ABI-based LBP rates were higher in the bypass group than in the EVT group. SPP-based LBP rates at 3 months were 73.8% (95% CI 63.4% to 84.2%) in the bypass group and 46.2% (95% CI 38.5% to 53.8%) in the EVT group; the corresponding ABI-based LBP rates were 71.5% (95% CI 61.8% to 81.2%) and 44.0% (95% CI 37.3% to 50.7%).

CONCLUSION

LBP is an important concept in the new global vascular guidelines for assessing the anatomic and hemodynamic status of CLTI patients. The present study found that LBP was significantly lower in the EVT group vs the bypass surgery group.

Percutaneous Vascular Interventions Versus Bypass Surgeries in Patients With Critical Limb Ischemia: A Comprehensive Meta-analysis

OBJECTIVE

The aim of our study was to compare percutaneous vascular interventions (PVI) versus bypass surgeries (BSX) in patients with critical limb ischemia (CLI).

BACKGROUND

Previous relevant reviews with limited numbers of included studies did not strictly confine the inclusion criteria to CLI, also involving patients with severe claudication, which may introduce bias in the decision-making of CLI revascularization. Current treatment strategies for CLI still remain controversial.

METHODS

We performed a meta-analysis of all available randomized controlled trials and observational clinical studies comparing PVI with BSX in CLI patients. Primary endpoints included overall survival, amputation-free survival, 30-day mortality, and major adverse cardiovascular and cerebrovascular events.

RESULTS

We identified 45 cohorts and 1 RCT in over 20,903 patients. In overall population, PVI reduced the risks of 30-day mortality [odds ratio (OR) 0.69, 95% confidence interval (CI) 0.51-0.95), major adverse cardiovascular and cerebrovascular events (OR 0.42, 95% CI 0.29-0.61), and surgical site infection (OR 0.31, 95% CI 0.19-0.51), but increased the risks of long-term all-cause mortality [hazard ratio (HR) 1.16, 95% CI 1.05-1.27) and primary patency failure (HR 1.31, 95% CI 1.08-1.58). When compared with autogenous BSX, PVI was also associated with additional increased risks of long-term death or amputation (HR 1.41, 95% CI 1.02-1.94) and secondary patency failure (HR 1.51, 95% CI 1.17-1.95). In patients with infrapopliteal lesions, we found PVI had inferior primary patency (HR 1.39, 95% CI 1.10-1.75) compared with BSX.

CONCLUSION

For patients in good physical condition with long life-expectancy, BSX may represent a better choice compared with PVI, particularly when autogenous bypass is available. While enhanced perioperative care for cardiovascular events and surgical site should be considered in patients underwent BSX to achieve comparable short-term outcomes provided by PVI.

Wound Blush Obtainment Is the Most Important Angiographic Endpoint for Wound Healing

OBJECTIVES

This study aimed to assess the optimal angiographic endpoint of endovascular therapy (EVT) for wound healing.

BACKGROUND

Several reports have demonstrated acceptable patency and limb salvage rates following infrapopliteal interventions for the treatment of critical limb ischemia (CLI). However, the optimal angiographic endpoint of EVT remains unclear.

METHODS

We conducted a subanalysis of the prospective multicenter OLIVE (Endovascular Treatment for Infrainguinal Vessels in Patients with Critical Limb Ischemia) registry investigation assessing patients who received infrainguinal EVT for CLI. We analyzed data from 185 limbs with ischemic ulcerations classified as Rutherford class 5 or 6, managed with EVT alone (i.e., not undergoing bypass surgery). The wound healing rate after EVT was estimated by the Kaplan-Meier method. The association between final angiographic data and wound healing was assessed employing a Cox proportional hazards model.

RESULTS

The overall wound healing rate was 73.5%. The probabilities of wound healing in patients with wound blush obtainment was significantly higher than that of those without wound blush (79.6% vs. 46.5%; p = 0.01). In the multivariate analysis, wound blush obtainment was an independent predictor of wound healing.

CONCLUSION

The presence of wound blush after EVT is significantly associated with wound healing. Wound blush as an angiographic endpoint for EVT may serve as a novel predictor of wound healing in patients with CLI.

Clinical outcome of angiosome-oriented infrapopliteal percutaneous transluminal angioplasty for isolated infrapopliteal lesions in patients with critical limb ischemia

PURPOSE

We aimed to evaluate the clinical usefulness and outcome of angiosome-oriented percutaneous transluminal angioplasty (IP-PTA) and its clinical outcome for isolated infrapopliteal lesions in diabetic critical limb ischemia.

METHODS

We retrospectively reviewed 70 patients (82 limbs) with diabetic critical limb ischemia who had localized disease at the level of the infrapopliteal artery. Patients underwent IP-PTA between January 2011 and December 2013 and were followed up for a mean of 13 months. The primary target arterial lesions were chosen according to the angiosome concept. We evaluated clinical findings, technical success, and patients' clinical outcome. The angiographic outcome of IP-PTA was assessed using the angiosome score. We analyzed the relationship between the angiosome score and the amputation rate.

RESULTS

There were 69 anterior tibial artery (ATA) lesions, 70 posterior tibial artery (PTA) lesions, and 58 peroneal artery (PA) lesions. The primary target arteries were the ATA (n=43), PTA (n=26), PA (n=2), and ATA + PTA (n=11). We divided the treated limbs into target (n=63) and nontarget (n=19) groups. The overall initial technical success rate was 91.4%. Successful wound healing rates were 87.3% (55/63) and 47.3% (9/19) in the target and nontarget groups, respectively (P < 0.05).

CONCLUSION

Angiosome-oriented primary targeted IP-PTA shows a highly effective treatment outcome in diabetic critical limb ischemia. In cases with inadequate angioplastic results of the target artery, IP-PTA of the nontarget artery should be recommended to improve the limb salvage rates.

Effectiveness of revascularization of the ulcerated foot in patients with diabetes and peripheral artery disease: a systematic review

Symptoms or signs of peripheral artery disease (PAD) can be observed in up to 50% of the patients with a diabetic foot ulcer and is a risk factor for poor healing and amputation. In 2012, a multidisciplinary working group of the International Working Group on the Diabetic Foot published a systematic review on the effectiveness of revascularization of the ulcerated foot in patients with diabetes and PAD. This publication is an update of this review and now includes the results of a systematic search for therapies to revascularize the ulcerated foot in patients with diabetes and PAD from 1980 to June 2014. Only clinically relevant outcomes were assessed. The research conformed to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and Scottish Intercollegiate Guidelines Network methodological scores were assigned. A total of 56 articles were eligible for full-text review. There were no randomized controlled trials, but there were four nonrandomized studies with a control group. The major outcomes following endovascular or open bypass surgery were broadly similar among the studies. Following open surgery, the 1-year limb salvage rates were a median of 85% (interquartile range of 80-90%), and following endovascular revascularization, these rates were 78% (70-89%). At 1-year follow-up, 60% or more of ulcers had healed following revascularization with either open bypass surgery or endovascular techniques. Studies appeared to demonstrate improved rates of limb salvage associated with revascularization compared with the results of conservatively treated patients in the literature. There were insufficient data to recommend one method of revascularization over another. There is a real need for standardized reporting of baseline demographic data, severity of disease and outcome reporting in this group of patients.

Current accepted hemodynamic criteria for critical limb ischemia do not accurately stratify patients at high risk for limb loss

OBJECTIVE

Critical limb ischemia (CLI) has been defined as rest pain or tissue loss in patients who have an ankle-brachial index (ABI) ≤0.50, ankle pressure (AP) <70 mm Hg, or toe pressure (TP) <50 mm Hg. Data suggesting that these patients are at high risk for limb loss without successful revascularization are limited. This study was designed to identify limb loss and mortality rates in patients who did not respond to revascularization or who were not revascularized to determine whether CLI hemodynamic criteria accurately identify patients at high risk for limb loss.

METHODS

Between 2008 and 2010, all patients undergoing lower extremity arterial duplex ultrasound testing at our hospital were identified. Those with ABI <0.50, AP <70 mm Hg, or TP <50 mm Hg were retrospectively reviewed to determine whether they had symptoms of rest pain, ischemic ulceration, or gangrene qualifying them for analysis in the database. Patients who underwent revascularization and subsequently had postrevascularization ABI, AP, or TP greater than the CLI criteria were removed from the cohort. Demographic factors, wound healing, amputation rates, and mortality were obtained and analyzed in relation to the initial APs and TPs. Outcomes were measured by Kaplan-Meier life-table analysis and Cox proportional hazards models.

RESULTS

In 381 patients identified in the study, 443 limbs met CLI criteria. After revascularization, 98 limbs with ABI or TP that improved to >0.5 and >50 mm Hg, respectively, were removed from the study cohort. In 45 limbs, patients did not respond to initial revascularization as their ABI, AP, or TP remained within CLI criteria. These limbs remained in the patient cohort, yielding a final group of 296 patients and 345 limbs. Mean follow-up was 2 years. In the entire patient cohort, limb loss occurred in 24% at 1 year and in 31% at 3 years. Mortality was 32% at 1 year and 56% at 3 years. Amputation-free survival was 54% at 1 year and 28% at 3 years. Lower TPs were associated with a statistically higher incidence of amputation. Among those with an initial TP ≤10 mm Hg (n = 85), limb loss occurred in 46% at 1 year and 60% at 3 years. This limb loss was significantly greater than limb loss among those with a TP of 31 to 50 mm Hg (n = 115; 18% at 3 years; P < .001) Amputation-free survival in patients with a TP ≤10 mm Hg was 8% at 3 years.

CONCLUSIONS

CLI is associated with a high mortality, but not all patients with currently defined hemodynamic criteria for CLI are at high risk of limb loss. Patients with a TP between 31 and 50 mm Hg (41% of the cohort) and not receiving revascularization or not responding hemodynamically to revascularization experienced a low risk of limb loss. We recommend revising the hemodynamic criteria for CLI to better identify patients at high risk for limb loss who require intervention to improve outcomes.

Endovascular techniques in limb salvage: infrapopliteal angioplasty

Critical limb ischemia (CLI) results from inadequate blood flow to supply and sustain the metabolic needs of resting muscle and tissue. Infragenicular atherosclerosis is the most common cause of CLI, and it is more likely to develop when multilevel or diffuse arterial disease coincides with compromised run-off to the foot. Reports of good technical and clinical outcomes have advanced the endovascular treatment options, which have gained a growing acceptance as the primary therapeutic strategy for CLI, especially in patients with significant risk factors for open surgical bypass. In fact, endovascular recanalization of below-the-knee arteries has proven to be feasible and safe, reduce the need for amputation, and improve wound healing. The distribution of various vascular territories or angiosomes in the foot has been recognized, and it appears advantageous to revascularize the artery supplying the territory directly associated with tissue loss. In addition, the targeted application and local delivery of drugs using drug-coated balloons (DCB) during angioplasty has the potential to improve patency rates compared to balloon angioplasty alone.

Endovascular Treatment for Infrainguinal Vessels in Patients With Critical Limb Ischemia

Background—

Recent technical advances have made endovascular treatment (EVT) an alternative first-line treatment for critical limb ischemia.

Methods and Results—

A prospective multicenter study was conducted to evaluate the clinical outcomes of 314 Japanese critical limb ischemia patients (mean age, 73±10 years) with infrainguinal arterial lesions who underwent EVT. Patients were enrolled from December 2009 to July 2011 and were followed-up for 12 months. The primary end point was amputation-free survival (AFS) at 12 months. Secondary end points were anatomic, clinical, and hemodynamic measures, including 12-month freedom from major adverse limb events. The 12-month AFS rate was 74%, with body mass index <18.5 (hazard ratio [HR], 2.22; P =0.008), heart failure (HR, 1.73; P =0.04), and wound infection (HR, 1.89; P =0.03) associated with a poor prognosis for AFS. The 12-month major adverse limb event-free rate was 88%, with hemodialysis (HR, 1.98; P =0.005), heart failure (HR, 1.69; P =0.02), and Rutherford classification 6 (HR, 2.25; P =0.002) associated with a poor prognosis for major adverse limb events. The median time for wound healing was 97 days, with body mass index <18.5 (HR, 0.54; P =0.03) and wound infection (HR, 0.60; P =0.04) being significant risk factors for unhealed wounds after EVT. At 12 months, 34% had undergone reintervention (bypass surgery, 2.6%; repeat EVT, 31.7%), and 73% were major adverse event–free.

Conclusions—

The high reintervention rate notwithstanding, EVT was an effective treatment for Japanese critical limb ischemia patients with infrainguinal disease, with satisfactory AFS and major adverse limb event-free rates. The results of this study will be helpful for the future evaluation of critical limb ischemia therapy.

Clinical Trial Registration—

URL: http://www.umin.ac.jp/ctr . Unique identifier: UMIN000002830.