Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

Diversity in randomized clinical trials for peripheral artery disease: a systematic review

BACKGROUND

Significant race and sex disparities exist in the prevalence, diagnosis, and outcomes of peripheral artery disease (PAD). However, clinical trials evaluating treatments for PAD often lack representative patient populations. This systematic review aims to summarize the demographic representation and enrollment strategies in clinical trials of lower-extremity endovascular interventions for PAD.

METHODS

Following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched multiple sources (Medline, EMBASE, Cochrane, Clinicaltrials.gov, WHO clinical trial registry) for randomized controlled trials (RCTs), RCT protocols, and peer-reviewed journal publications of RCTs conducted between January 2012 and December 2022. Descriptive analysis was used to summarize trial characteristics, publication or study protocol characteristics, and the reporting of demographic characteristics. Meta-regression was used to explore associations between demographic characteristics and certain trial characteristics.

RESULTS

A total of 2,374 records were identified. Of these, 59 met the inclusion criteria, consisting of 35 trials, 14 publications, and 10 protocols. Information regarding demographic representation was frequently missing. While all 14 trial publications reported age and sex, only 4 reported race/ethnicity, and none reported socioeconomic or marital status. Additionally, only 4 publications reported clinical outcomes by demographic characteristics. Meta-regression analysis revealed that 6% more women were enrolled in non-European trials (36%) than in European trials (30%).

CONCLUSIONS

The findings of this review highlight potential issues that may compromise the reliability and external validity of study findings in lower-extremity PAD RCTs when applied to the real-world population. Addressing these issues is crucial to enhance the generalizability and impact of clinical trial results in the field of PAD, ultimately leading to improved clinical outcomes for patients in underrepresented populations.

REGISTRATION

The systematic review methodology was published in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022378304).

Comparing Endovascular Approaches in Lower Extremity Artery Disease: Insights from a Network Meta-Analysis

BACKGROUND

Endovascular therapy offers an alternative for treating femoropopliteal (FP) and infrapopliteal (IP) lesions related to occlusive lower extremity artery disease. Despite numerous trials, the effectiveness of restenosis prevention using local drug delivery devices remains a topic of debate.

OBJECTIVES

An updated systematic review and network meta-analysis was conducted. Our overall aim was to summarize the most recent clinical evidence regarding endovascular approaches for FP and IP atherosclerotic lesions.

METHODS

We conducted a search for randomized trials in the MEDLINE database, and extracted data related to clinical endpoints. Our primary focus was on the rate of major adverse events (MAEs), including mortality, amputation, and target lesion revascularization (TLR). A multiple treatment network meta-analysis supplemented with component network analyses was performed to examine the impact of combined treatment.

RESULTS

Our search yielded 33 randomized controlled trials encompassing 5766 patients. This included 19 studies focused on femoropopliteal and 14 on IP lesions, accounting for 3565 and 2201 patients, respectively. Drug-coated balloons (DCBs) and drug-eluting stents (DESs) displayed a reduced MAE risk in comparison to plain old balloon angioplasty (POBA)-RR for DCB: 0.64 (95% CI: 0.52-0.77) and for DES: 0.71 (95% CI: 0.51-0.99). The bare-metal stent (BMS) group manifested the most substantial MAE risk, being 59% higher relative to the DCB cohort (BMS vs. DCB RR: 1.59; 95% CI: 1.03-2.47). For FP lesions, DES was the standout performer, curtailing MAE risk by 55% relative to POBA. Within IP lesions, DES mitigated the MAE risk by 25% versus POBA. DCB did not exhibit any notable MAE reduction when pitted against POBA.

CONCLUSION

In FP arteries, both DESs and DCBs yielded significantly diminished MAEs, thus outpacing other techniques. Regarding IP arteries, only DESs resulted in significantly fewer MAEs. In alignment with contemporary research, our findings revealed no signs of elevated mortality in patients undergoing treatment with drug-eluting apparatuses.

Interventional Treatment Options for the Prevention of Amputation in Patients With Lower Extremity Wounds From Peripheral Arterial Disease

BACKGROUND

Peripheral arterial disease and related lower extremity wounds are prominent causes of amputation. Revascularization may reduce amputation rates or the amputation margin more distally in patients with peripheral arterial disease who have wounds resulting from critical limb ischemia. This study examined the association of risk factors and intervention types with amputation rates in patients with critical lower extremity arterial disease.

METHODS

A total of 211 patients who underwent peripheral intervention because of foot wound were followed up for 12 months after the intervention. All patients had lower extremity wounds resulting from peripheral arterial disease. The effects of treatment approaches were compared in patients who underwent and did not undergo amputation.

RESULTS

Revascularization of the anterior tibial artery reduced the amputation rate by 6.52 times compared with occlusion. Posterior tibial artery revascularization reduced the amputation rate by 49.95 times.

CONCLUSION

In this study of percutaneous intervention methods for prevention of amputation, the most effective option was revascularization of the posterior tibial artery and anterior tibial artery. Considering these results, treatment of critical peripheral arterial disease can be cost-effective and efficient and may shorten procedure time.

Predicting outcomes following lower extremity open revascularization using machine learning

Lower extremity open revascularization is a treatment option for peripheral artery disease that carries significant peri-operative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following lower extremity open revascularization. The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity open revascularization for chronic atherosclerotic disease between 2011 and 2021. Input features included 37 pre-operative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using tenfold cross-validation, we trained 6 ML models. Overall, 24,309 patients were included. The primary outcome of 30-day MALE or death occurred in 2349 (9.3%) patients. Our best performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.93 (0.92-0.94). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.08. Our ML algorithm has potential for important utility in guiding risk mitigation strategies for patients being considered for lower extremity open revascularization to improve outcomes.

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.

Comparison of Transcatheter Arterialization of Deep Veins to Standard of Care in Patients with No-Option Chronic Limb Threatening Ischemia

BACKGROUND

Patients with no-option chronic limb-threatening ischemia (no-option CLTI) have limited therapeutic options. The PROMISE II study evaluated, transcatheter arterialization of deep veins (TADV) as a treatment option for no-option CLTI. In the current study patients from PROMISE II were compared to patients from a registry of untreated no-option CLTI patients (CLariTI: Natural Progression of High-Risk Chronic Limb-Threatening Ischemia).

METHODS

We used propensity matching to compare patients from the PROMISE II prospective study of the TADV intervention with simultaneously enrolled CLTI patients that were note candidates for PROMISE II but were enrolled in to CLariTI natural history registry. Untreated no-option CLTI (CLariTI) patients could either be no-option or patients who did not meet PROMISE II entry criteria. Risk difference between groups was calculated using common risk difference and P values were provided by propensity-score stratified Mantel-Haenszel test. The primary endpoint was amputation-free survival (AFS).

RESULTS

Diabetes was present in over 75% of patients. All patients had tissue loss and 35-46% had extensive tissue loss (Rutherford 6). The unadjusted AFS at 6 months, was 66.1% by Kaplan-Meier estimate for PROMISE II patients (n = 105) compared to 39.1% in the no-option cohort of CLariTI (n = 121) and 44.0% in the full cohort (no-option and patients not meeting entry criteria combine, n = 180). The treatment group who underwent TADV for no-option CLTI had an absolute difference of 29% improved (P < 0.0001) propensity-adjusted risk difference in AFS and a relative event rate reduction of 45% compared to the no-option control patients.

CONCLUSIONS

Transcatheter arterialization of deep veins (TADV) resulted in improved 6 month AFS in no-option CLTI patients and appears to be a promising therapy in patients with no-option CLTI.

Treatment of Femoropopliteal Artery Disease with Polymer-Coated Drug-Eluting Stent: 5-Year Results of a Prospective, Non-Randomized Study Including the Halo Phenomenon

PURPOSE

To investigate the long-term results of the Eluvia drug-eluting stent (DES) implantation for femoropopliteal arterial disease, including the 'halo' phenomenon. Long-term data of DES is scarce. A focal reaction ('halo') following Eluvia DES deployment has been described. However, the long-term clinical impact of this phenomenon remains unclear.

METHODS

This prospective, non-randomized, single-arm study included 130 consecutive patients treated with an Eluvia DES for symptomatic femoropopliteal disease between March 2016 and December 2018. Clinical outcomes and imaging were assessed after 6 months and annually thereafter for up to 5 years. The primary outcome measure was primary patency. Secondary outcomes were freedom from clinically driven target lesion revascularization (CD-TLR), freedom from major amputation, overall survival and amputation-free survival rates.

RESULTS

The primary patency was 65% at 5 years. The freedom from CD-TLR and from major amputation at 5 years was 79 and 96%, respectively. The overall survival and amputation-free survival rates were 88 and 83% at 60 months, respectively. Out of the 27 patients with a halo sign, two showed an increased (7.4%) and 6 (22.2%) a decreased diameter. In 19 cases (70.4%), the diameter remained unchanged at the latest follow-up. The presence of the 'halo' sign was associated with increased primary patency (87% versus 59%, HR: 2.48, 95%CI 1.19-5.16, P = .015).

CONCLUSIONS

The presented patient cohort treated with the Eluvia DES for femoropopliteal artery lesions indicates durable efficacy and a good safety profile regardless of the halo phenomenon. The results need to be confirmed in a larger patient cohort.

LEVEL OF EVIDENCE III

Non-randomized controlled cohort/follow-up study.

Outcomes of Endovascular Treatment for Critical Limb Threatening Ischemia

BACKGROUND

Critical limb threatening ischemia (CLTI), particularly in patients with ischemic ulceration has been associated with significant morbidity and mortality. Typically, endovascular therapy has been first-line therapy for our patients, but this strategy has come into question based upon the Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Threatening Ischemia (BEST-CLI) trial data.

METHODS AND RESULTS

For comparative purposes, we evaluated outcomes from 150 CLTI patients with ischemic ulceration treated with endovascular-first therapy. The mean age was 72 years in this predominate male, Caucasian, ambulatory group. The major co-morbidities were smoking history in 49% and diabetes mellitus in 67%.` Anatomic scoring, using Society for Vascular Surgery criteria, revealed only 35.6% had favorable anatomy (Global Limb Anatomical Staging System stage of 0,1) for long-term patency compared to 64.4% of limbs with unfavorable anatomy for long-term patency (Global Limb Anatomical Staging System stage 2,3). Stents were used in 47% of cases. Reintervention occurred in 36% over 24 months follow-up. At 12 and 24 months, the Kaplan-Meier projections for survival was 0.80 (0.73, 0.87) and 0.69 (0.59, 0.79); amputation was 0.69 (0.61, 0.77) and 0.59 (0.46, 0.71); amputation-free survival (AFS) was 0.56 (0.48, 0.65) and 0.38 (0.27, 0.50), respectively. Amputation was more common in those with reinterventions (P = 0.033). Mortality was predicted with ankle brachial index ≤0.40 or ≥1.30 (P = 0.0019) and the presence of infection (P = 0.0047). AFS was predicted by the presence of any infection (P = 0.0001).

CONCLUSIONS

Despite technically successful endovascular treatment, patients who present with CLTI maintain a high-risk for limb loss and mortality. Amputation prevention must vigilantly address infection risk. These data correlate with outcomes from BEST-CLI trial enhancing applicability to patient-centered care.

Risk Analysis and Clinical Outcomes in Chronic Limb-threatening Ischemia Patients with Surgical Site Infection after Distal Bypass

BACKGROUND

A recent randomized control study showed that long-term outcomes after surgical revascularization were superior to those after endovascular treatment for cases with chronic limb-threatening ischemia (CLTI) with an appropriate single-segment great saphenous vein. However, surgical site infection (SSI) in CLTI cases after infrapoplital bypass also resulted in a prolonged hospital stay and poor outcomes, including graft disruption. The aim of the current study was to analyze risk factors for SSI in CLTI patients after distal bypass and to compare outcomes in patients with and without SSI.

METHODS

A total of 515 cases that underwent distal bypass at a single center between 2009 and 2022 were analyzed retrospectively. Comparisons were made between patients with and without SSI after distal bypass. The primary end point was limb salvage after distal bypass.

RESULTS

Of the 515 cases that underwent distal bypass, 79 (15%) had SSI. The risk factors for SSI were preoperative antibacterial drug use (P = 0.001), pedal bypass (P = 0.001), and prolonged operation time (≥150 min) (P = 0.010). The median hospital stay in SSI cases was longer than that in non-SSI cases (P < 0.001). Of 515 distal bypasses, 7 (1.3%) bypass grafts ruptured postoperatively due to SSI, and of these 7 cases, 6 ruptured during the day, 5 cases occurred within 1 month postoperatively, and 2 patients (29%) are alive without amputation. The mean follow-up period was 34 ± 30 months. During follow-up, 62 limbs (SSI cases, 19; non-SSI cases, 43) required major amputation and there were 234 deaths (SSI cases, 46; non-SSI cases, 188). The 1-, 3-, and 5-year limb salvage rates of 82%, 71%, and 62%, respectively, in SSI cases were significantly lower than those in non-SSI cases (P < 0.001). The 5-year survival rate of 29% in SSI cases showed a tendency to be lower than that in non-SSI cases (P = 0.058).

CONCLUSIONS

The limb salvage rate in SSI cases was lower than in non-SSI cases after distal bypass. Graft rupture due to SSI occurred at a rate of 1.3% and resulted in poor outcomes in most cases. SSIs adversely affect outcomes and further study is needed to identify methods to avoid SSI following distal bypass.

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.

Drug-Eluting Resorbable Scaffold versus Angioplasty for Infrapopliteal Artery Disease

BACKGROUND

Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. The effect of the use of drug-eluting resorbable scaffolds on these outcomes remains unknown.

METHODS

In this multicenter, randomized, controlled trial, 261 patients with CLTI and infrapopliteal artery disease were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting resorbable scaffold or angioplasty. The primary efficacy end point was freedom from the following events at 1 year: amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion. The primary safety end point was freedom from major adverse limb events at 6 months and from perioperative death.

RESULTS

The primary efficacy end point was observed (i.e., no events occurred) in 135 of 173 patients in the scaffold group and 48 of 88 patients in the angioplasty group (Kaplan-Meier estimate, 74% vs. 44%; absolute difference, 30 percentage points; 95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group (absolute difference, -3 percentage points; 95% CI, -6 to 0; one-sided P<0.001 for noninferiority). Serious adverse events related to the index procedure occurred in 2% of the patients in the scaffold group and 3% of those in the angioplasty group.

CONCLUSIONS

Among patients with CLTI due to infrapopliteal artery disease, the use of an everolimus-eluting resorbable scaffold was superior to angioplasty with respect to the primary efficacy end point. (Funded by Abbott; LIFE-BTK ClinicalTrials.gov number, NCT04227899.).

Critical Limb Ischaemia in Octogenarians: Treatment Outcomes Compared With Younger Patients

Objective

A growing proportion of patients with chronic limb threatening ischaemia (CLTI) are elderly, the most challenging for management decisions. The aim was to study the patient profile and outcome of CLTI in octogenarian patients, comparing them with younger patients.

Methods

Retrospective cohort of consecutive patients hospitalised for CLTI with infrainguinal disease in a Spanish centre (2013-2020). Data on age, comorbidity, anatomical characteristics, and treatment were gathered. Patients were stratified according to age (<80 and ≥80 years). The primary outcomes were overall survival and limb salvage (LS), analysed using Kaplan-Meier and Cox regression.

Results

: A total of 512 patients were enrolled: 305 were <80 years old with mean age 69.7 ± standard deviation (SD) 8.2 years, and 207 were ≥80 years old with mean age 85.3 ± SD 3.6 years. Smoking and diabetes mellitus were more frequent in younger patients (78.0% vs. 45.4%, p < .001; 68.5% vs. 59.5%, p = .037 respectively). Older patients had a higher prevalence of heart and kidney disease (70.5% vs. 57.0%, p = .002; 39.6% vs. 24.3%, p < .001, respectively). The arterial disease was femoropopliteal or tibial in 68.9% and 31.1% in patients <80 years and 58.9% and 41.1% in patients ≥80 years (p = .021). In younger patients, conservative treatment was indicated in 18.0%, endovascular treatment (ET) in 41.6%, and open or hybrid surgery (OS) in 40.3%; in patients ≥80 years these were 36.9%, 37.4%, and 25.7%, respectively (p <. 001). Mean follow up was 23.3 ± SD 17.4 months. One and two year overall survival was 85.4% and 73.0% in younger patients and 64.1% and 51.3% in patients ≥80 years (p < .001). LS was 83.7% and 79% at the same times in younger patients and 75.3% and 72.1% in older ones (p = .045). In younger patients ET led to worse LS than OS (p = .005) but not in older patients (p = .29).

Conclusion

Patients ≥80 years with CLTI have higher comorbidity and lower life expectancy and receive conservative treatment more frequently than younger patients. ET and OS are associated with similar survival and LS in these older patients.

Outcomes of Arterial Bypass With the Human Acellular Vessel for Chronic Limb-Threatening Ischemia Performed Under the FDA Expanded Access Program

OBJECTIVE

To report outcomes of the human acellular vessel (HAV) implanted for limb salvage through the Food and Drug Administration (FDA) Expanded Access Program for patients with chronic limb-threatening ischemia with no autologous conduit.

METHODS

The HAV is a bioengineered vascular conduit designed with human vascular smooth muscle cells. The product is under regulatory study. From April 2019 to November 2021, the HAV was implanted in 14 patients (12 men; mean age, 62±14 years) at 3 US centers. Each case was performed with a single-use investigational new drug Expanded Access Program issued by the FDA. Institutional review board approval was obtained; technical and clinical outcomes were analyzed.

RESULTS

A single 6-mm-diameter (40-cm-long) HAV was implanted in 9 patients; 5 patients required 2 HAVs sewn together as a composite. Technical success was 100%. Median follow-up was 12 (range, 1 to 41) months. Primary and secondary patency rates were 72% and 81% at 12 months; assisted primary patency was attained in 4 patients. Amputation-free survival was 93% at 6 months and 77% at 12 months. All patients with a patent HAV experienced clinical improvement with no HAV-related infections or adverse events. There were 4 deaths in the cohort, late mortality unrelated to the HAV.

CONCLUSION

The HAV is a safe and effective "off-the-shelf" biologic conduit. This experience from the FDA Expanded Access Program in this population with few alternative limb salvage options will help guide regulatory deliberations for patients with lower extremity ischemia and no autologous bypass conduit options.

Association between End-Stage Renal Disease and Major Adverse Limb Events after Peripheral Vascular Intervention

PURPOSE

To examine the effect of end-stage renal disease (ESRD) on the likelihood of major adverse limb events (MALEs) in patients with Rutherford Category 4-6 critical limb ischemia (CLI) who underwent percutaneous vascular intervention (PVI).

MATERIALS AND METHODS

Two contemporaneous cohorts of patients who underwent PVI for symptomatic CLI from 2012 to 2022, differing in ESRD status, were matched using propensity score methods. This database identified 628 patients who underwent 1,297 lower extremity revascularization procedures; propensity score matching yielded 147 patients (180 limbs, 90 limbs in each group). Kaplan-Meier and Cox proportional hazard analyses were used to assess the effect of ESRD status on MALEs, stratified into major amputation (further stratified into above-knee amputation and below-knee amputation [BKA]) and reintervention (PVI or bypass).

RESULTS

After PVI, 31.3% of patients in the matched cohorts experienced a MALE (45.7% ESRD vs 18.2% non-ESRD), and 15.6% experienced a major amputation (27.1% ESRD vs 5.2% non-ESRD). Cox proportional hazards analysis revealed that ESRD was an independent predictor of MALE (hazard ratio [HR], 3.15; 95% CI, 1.58-6.29; P = .001), major amputation (HR, 7.00; 95% CI, 2.06-23.79; P = .002), and BKA (HR, 7.56; 95% CI, 1.71-33.50; P = .008).

CONCLUSIONS

ESRD is strongly predictive of MALE and major amputation risk, specifically BKA, in patients undergoing PVI for Rutherford Category 4-6 CLI. These patients warrant closer follow-up, and new methods may become necessary to predict and further reduce their amputation risk.

Impact of routine surveillance duplex ultrasound and subsequent reintervention after superficial femoral artery stenting

OBJECTIVE

Superficial femoral artery (SFA) stenting is a common treatment for peripheral artery disease. It is effective in the short term; however, in-stent restenosis (ISR) limits long-term success. Surveillance with duplex ultrasound (DUS) can identify patients who develop ISR leading to early reintervention, but data to support this practice is sparce. The purpose of this study was to evaluate whether surveillance and subsequent reintervention improves outcomes in patients with SFA stents.

METHODS

A single-center, retrospective study was performed with patients undergoing SFA stenting between 2005 and 2020 who had a follow-up with DUS. Five groups were identified based on the presence of ISR on DUS (ISR vs no ISR [NISR]), recurrence of symptoms (symptomatic [SX] vs asymptomatic [ASX]), and if any reintervention was performed (reintervention [R] vs no reintervention [NR]): (1) ISR+SX+R; (2) ISR+SX+NR; (3) ISR+ASX+R; (4) ISR+ASX+NR; and (5) NISR+NR. The primary endpoint was amputation-free survival, and the secondary endpoint was patency. Predictors of mortality and surveillance were identified by multivariable logistic regressions and Cox multivariate regression models. Survival curves were presented as Kaplan-Meier plots using log-rank test for subgroup comparison.

RESULTS

Two hundred fifty-seven patients were included in the analysis. The indication for intervention was claudication in 28% and chronic limb-threatening ischemia in 72%. A total of 161 patients (63%) underwent reintervention for ISR. Of patients who had restenosis on DUS, those who were symptomatic and did not undergo reintervention (ISR+SX+NR) did the worst, with 50% amputation rate. In contrast, those who were asymptomatic but did undergo reintervention (ISR+ASX+R) had the lowest amputation rate of 13%. Active smoking was a predictor of both loss of patency and amputation (1.72; 95% confidence interval [CI], 1.00-2.98; P = .050; 3.55; 95% CI, 1.53-8.25; P = .003). Post procedure dual antiplatelet therapy had a positive association with limb salvage (hazard ratio [HR], 0.23; 95% CI, 0.09-0.58; P = .001), whereas diabetes (HR, 2.61; 95% CI, 1.21-6.01; P = .019), stent occlusion (HR, 17.0; 95% CI, 5.93-63.1; P < .001), and chronic limb-threatening ischemia presentations (HR, 4.31; 95% CI, 1.86-11.7; P=.002) were negatively associated with limb salvage.

CONCLUSIONS

Routine surveillance DUS and subsequent reintervention on ISR after SFA stenting is associated with improved patency and amputation-free survival. Surveillance DUS should be routine for patients after stenting, with reintervention strongly considered if ISR is identified for both symptomatic and asymptomatic.

Assessing the robustness of positive vascular surgery randomized controlled trials using their fragility index

OBJECTIVE

The fragility index (FI) measures the robustness of statistically significant findings in randomized controlled trials (RCTs) by quantifying the minimum number of event conversions required to reverse a dichotomous outcome's statistical significance. In vascular surgery, many clinical guidelines and critical decision-making points are informed by a handful of key RCTs, especially regarding open surgical versus endovascular treatment. The objective of this study is to evaluate the FI of RCTs with statistically significant primary outcomes that compared open vs endovascular surgery in vascular surgery.

METHODS

In this meta-epidemiological study and systematic review, MEDLINE, Embase, and CENTRAL were searched for RCTs comparing open versus endovascular treatments for abdominal aortic aneurysms, carotid artery stenosis, and peripheral arterial disease to December 2022. RCTs with statistically significant primary outcomes were included. Data screening and extraction were conducted in duplicate. The FI was calculated by adding an event to the group with the smaller number of events while subtracting a nonevent to the same group until Fisher's exact test produced a nonstatistically significant result. The primary outcome was the FI and proportion of outcomes where the loss to follow-up was greater than the FI. The secondary outcomes assessed the relationship of the FI to disease state, presence of commercial funding, and study design.

RESULTS

Overall, 5133 articles were captured in the initial search with 21 RCTs reporting 23 different primary outcomes being included in the final analysis. The median FI (first quartile, third quartile) was 3 (3, 20) with 16 outcomes (70%) reporting a loss to follow-up greater than its FI. Mann-Whitney U test revealed that commercially funded RCTs and composite outcomes had greater FIs (median, 20.0 [5.5, 24.5] vs median, 3.0 [2.0, 5.5], P = .035; median, 21 [8, 38] vs median, 3.0 [2.0, 8.5], P = .01, respectively). The FI did not vary between disease states (P = .285) or between index and follow-up trials (P = .147). There were significant correlations between the FI and P values (Pearson r = 0.90; 95% confidence interval, 0.77-0.96), and the number of events (r = 0.82; 95% confidence interval, 0.48-0.97).

CONCLUSIONS

A small number of event conversions (median, 3) are needed to alter the statistical significance of primary outcomes in vascular surgery RCTs evaluating open surgical and endovascular treatments. Most studies had loss to follow-up greater than its FI, which can call into question trial results, and commercially funded studies had a greater FI. The FI and these findings should be considered in future trial design in vascular surgery.

Failure-to-Salvage After Femoropopliteal Bypass Surgery is Associated With Nonmodifiable Risk Factors

INTRODUCTION

Bypass graft failure and major amputation are among the worst complications after femoropopliteal bypass surgery. In this large multicenter analysis, we examined our incidence and risk factors for failure-to-salvage (FTS) following either bypass surgery or bypass graft failure.

METHODS

A regional multicenter database was retrospectively queried for all femoropopliteal bypass procedures performed between 2002 and 2021. Re-do bypasses were excluded. The primary outcome was FTS, defined as major ipsilateral limb amputation within 90 d following index bypass surgery or bypass graft failure. Bypass graft failure was defined as critical stenosis or occlusion of the bypass graft requiring reintervention. Graft rescue was defined as bypass graft failure without subsequent major ipsilateral limb amputation within 90 d. Multivariable logistic regression analysis was utilized to identify factors associated with bypass graft failure and FTS.

RESULTS

Over the study period, 1315 femoropopliteal bypass procedures were performed across five hospitals. There were 25 major amputations within 90 d of initial bypass. Bypass graft failure was diagnosed in an additional 503 (38.3%) patients. Mean time to graft failure was 619 d. On multivariable analysis, bypass for tissue loss (adjusted odds ratio [aOR] 1.38 [95% confidence interval (CI) 1.03-1.83], P = 0.03) was associated with graft failure. Of patients with graft failure, 33 had major amputation, leading to an overall FTS incidence of 4.4% (n = 58) over a mean follow-up period of 3.4 y. Patient demographics, medical comorbidities, and bypass conduits were similar between the FTS and graft rescue groups (n = NS each). The FTS group more frequently underwent bypass for tissue loss (51.7% versus 29.8%, P = 0.002), and an infrageniculate bypass target was more frequently utilized in FTS compared to graft rescue patients (81.0% versus 60.4%, P = 0.002). Anticoagulation (34.5% in FTS versus 37.7% in rescue) and dual antiplatelet therapy (15.5% versus 22.1%, respectively) were similar between groups (P = NS each). On multivariable analysis, factors associated with FTS included infrageniculate target (aOR 2.42 [95% CI 1.22-4.08], P = 0.01), black race (aOR 2.47 [95% CI 1.04-5.84], P = 0.04), and bypass for tissue loss (aOR 4.75 [95% CI 1.41-16.0], P = 0.01). Anticoagulation and dual antiplatelet therapy were not associated with loss of graft patency or FTS.

CONCLUSIONS

Failure-to-salvage after femoropopliteal bypass surgery is associated with nonmodifiable factors, and may represent progression of underlying disease. These data may help inform vascular surgeons in counseling patients with failing bypass grafts. Further investigation of care delivery factors improving likelihood of graft salvage may be warranted.

Heparin-Bonded Expanded Polytetrafluoroethylene Is a Solution for Infrapopliteal Revascularization in the Absence of an Adequate Autologous Vein Graft

BACKGROUND

To analyze the outcomes of heparin-bonded expanded polytetrafluoroethylene (HePTFE) graft as an alternative conduit in infrapopliteal revascularization of chronic limb-threatening ischemia (CLTI) in the absence of an autologous vein conduit.

METHODS

A single-center retrospective analysis of patients with CLTI submitted to infrapopliteal bypasses with autologous vein graft (VEIN group) or HePTFE graft (HePTFE group) was implemented. Primary end points were freedom from CLTI at 12 months and recurrence of CLTI at 3 years. Secondary end points included freedom from major amputation, amputation-free survival (AFS), survival, and primary (PP) and secondary patency (SP) rates at 3 years of follow-up.

RESULTS

A total of 348 limbs submitted to infrapopliteal bypasses, 214 with venous graft and 134 with HePTFE graft, were followed-up for a median of 25 months. Most patients of the HePTFE group were male (69%), with a median age of 76 years (interquartile range [IQR] 15). Fifty-nine percent of the limbs of the HePTFE group had Wound grade ≥2, being 46% of them infected. Eighty-eight percent were GLASS stage III. Freedom from CLTI was not significantly different between HePTFE and VEIN groups (75% vs. 84%, adjusted hazard ratio [aHR] 0.88, confidence interval [CI] 0.66-1.18, P = 0.401). Recurrence of CLTI was higher in the HePTFE group (42% vs.18% at 3 years; aHR 2.82, CI 1.59-5.00, P < 0.001). The VEIN group achieved higher rates of freedom from major amputation (87% vs.69% at 3 years; aHR 2.21, CI 1.31-3.75, P = 0.003) and AFS (59% vs. 37% at 3 years; aHR 1.39, CI 1.02-1.88, P = 0.036), but no significance in survival (aHR 1.10, CI 0.72-1.66, P = 0.667). Patency rates were inferior in the HePTFE group, with 2-year PP and SP rates of 52% vs. 74%, and 76% vs. 90%, respectively (PP: aHR 1.70, CI 1.11-2.59, P = 0.014; SP: aHR 2.51, CI 1.42-4.42, P = 0.001).

CONCLUSIONS

Infrapopliteal bypass with autologous vein graft is the gold standard to treat CLTI limbs. HePTFE graft should be regarded as an alternative for complex infrapopliteal revascularization when lacking an autologous vein conduct.

The Impact of Ejection Fraction on Major Adverse Limb Events after Lower Extremity Revascularization

BACKGROUND

Peripheral arterial disease (PAD) is commonly associated with coronary artery disease, and echocardiography is frequently performed before lower extremity revascularization (LER). However, the incidence of various echocardiographic findings in patients with PAD and their impact on the outcomes of LER has not been well studied. Reduced ejection fraction (EF) ≤ 40% is associated with increased major adverse limb events (MALE) after LER.

METHODS

The electronic medical records of patients undergoing LER in a single center were reviewed. Patients were divided based on the presence or absence of reduced EF. Patient, transthoracic echocardiogram, procedural characteristics, and outcomes were compared between the 2 groups.

RESULTS

A total of 1,114 patients (N = 131, 11.8% with reduced EF) underwent LER between 2013 and 2019. Patients with reduced EF were more likely to be male and have a history of coronary artery disease and heart failure. Furthermore, they were more likely to have diastolic dysfunction with moderate to severe mitral and tricuspid valve regurgitation. Patients with reduced EF were more likely to undergo LER for chronic limb-threatening ischemia, and to be treated with endovascular procedures. Perioperatively, patients with reduced EF were more likely to develop myocardial infarction. Lastly, the 2 groups had no difference in overall MALE or major amputation. However, on Kaplan-Meier curves, MALE-free survival was significantly lower for patients with reduced EF. Regression analysis demonstrated that indication and not EF was associated with MALE and MALE-free survival.

CONCLUSIONS

Reduced EF is associated with decreased MALE-free survival for patients with PAD undergoing LER.

Intravascular Ultrasound Use in Peripheral Arterial and Deep Venous Interventions: Multidisciplinary Expert Opinion From SCAI/AVF/AVLS/SIR/SVM/SVS

Percutaneous revascularization is the primary strategy for treating lower extremity venous and arterial disease. Angiography is limited by its ability to accurately size vessels, precisely determine the degree of stenosis and length of lesions, characterize lesion morphology, or correctly diagnose postintervention complications. These limitations are overcome with use of intravascular ultrasound (IVUS). IVUS has demonstrated the ability to improve outcomes following percutaneous coronary intervention, and there is increasing evidence to support its benefits in the setting of peripheral vascular intervention. At this stage in its evolution, there remains a need to standardize the use and approach to peripheral vascular IVUS imaging. This manuscript represents considerations and consensus perspectives that emerged from a roundtable discussion including 15 physicians with expertise in interventional cardiology, interventional radiology, and vascular surgery, representing 6 cardiovascular specialty societies, held on February 3, 2023. The roundtable's aims were to assess the current state of lower extremity revascularization, identify knowledge gaps and need for evidence, and determine how IVUS can improve care and outcomes for patients with peripheral arterial and deep venous pathology.

Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

INTRODUCTION

End-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions.

METHODS

Chronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted.

RESULTS

A total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention.

CONCLUSIONS

Patients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

Editor's Choice - Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL) Prospective Cohort Study and the Generalisability of the BASIL-2 Randomised Controlled Trial

OBJECTIVE

The Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2) randomised controlled trial has shown that, for patients with chronic limb threatening ischaemia (CLTI) who require an infrapopliteal (IP) revascularisation a vein bypass (VB) first revascularisation strategy led to a 35% increased risk of major amputation or death when compared with a best endovascular treatment (BET) first revascularisation strategy. The study aims are to place the BASIL-2 trial within the context of the CLTI patient population as a whole and to investigate the generalisability of the BASIL-2 outcome data.

METHODS

This was an observational, single centre prospective cohort study. Between 24 June 2014 and 31 July 2018, the BASIL Prospective Cohort Study (PCS) was performed which used BASIL-2 trial case record forms to document the characteristics, initial and subsequent management, and outcomes of 471 consecutive CLTI patients admitted to an academic vascular centre. Ethical approval was obtained, and all patients provided fully informed written consent. Follow up data were censored on 14 December 2022.

RESULTS

Of the 238 patients who required an infrainguinal revascularisation, 75 (32%) had either IP bypass (39 patients) or IP BET (36 patients) outside BASIL-2. Seventeen patients were initially randomised to BASIL-2. A further three patients who did not have an IP revascularisation as their initial management were later randomised in BASIL-2. Therefore, 95/471 (20%) of patients had IP revascularisation (16% outside, 4% inside BASIL-2). Differences in amputation free survival, overall survival, and limb salvage between IP bypass and IP BET performed outside BASIL-2 were not subject to hypothesis testing due to the small sample size. Reasons for non-randomisation into the trial were numerous, but often due to anatomical and technical considerations.

CONCLUSION

CLTI patients who required an IP revascularisation procedure and were subsequently randomised into BASIL-2 accounted for a small subset of the CLTI population as a whole. For a wide range of patient, limb, anatomical and operational reasons, most patients in this cohort were deemed unsuitable for randomisation in BASIL-2. The results of BASIL-2 should be interpreted in this context.

Bypass surgery versus endovascular revascularization for occlusive infrainguinal peripheral artery disease: a meta-analysis of randomized controlled trials for the development of the Italian Guidelines for the treatment of diabetic foot syndrome

To report a review and meta-analysis of all randomized controlled trials (RCTs) comparing bypass surgery (BS) and endovascular treatment (ET) in infrainguinal peripheral arterial disease (PAD) for several endpoints, such as major and minor amputation, major adverse limb events (MALEs), ulcer healing, time to healing, and all-cause mortality to support the development of the Italian Guidelines for the Treatment of Diabetic Foot Syndrome (DFS). A MEDLINE and EMBASE search was performed to identify RCTs, published since 1991 up to June 21, 2023, enrolling patients with lower limb ischemia due to atherosclerotic disease (Rutherford I-VI). Any surgical BS or ET was allowed, irrespective of the approach, route, or graft employed, from iliac to below-the-knee district. Primary endpoint was major amputation rate. Secondary endpoints were amputation-free survival major adverse limb events (MALEs), minor amputation rate, all-cause mortality, ulcer healing rate, time to healing, pain, transcutaneous oxygen pressure (TcPO2) or ankle-brachial index (ABI), quality of life, need for a new procedure, periprocedural serious adverse events (SAE; within 30 days from the procedure), hospital lenght of stay, and operative time. Twelve RCTs were included, one enrolled two separate cohorts of patients, and therefore, the studies included in the analyses were 13. Participants treated with ET had a similar rate of major amputations to participants treated with BS (MH-OR 0.85 [0.60, 1.20], p = 0.36); only one trial reported separately data on patients with diabetes (N = 1), showing no significant difference between ET and BS (MH-OR: 0.67 [0.09, 5.13], p = 0.70). For minor amputation, no between-group significant differences were reported: MH-OR for ET vs BS: 0.83 [0.21, 3.30], p = 0.80). No significant difference in amputation-free survival between the two treatment modalities was identified (MH-OR 0.94 [0.59, 1.49], p = 0.80); only one study reported subgroup analyses on diabetes, with a non-statistical trend toward reduction in favor of ET (MH-OR 0.62 [0.37, 1.04], p = 0.07). No significant difference between treatments was found for all-cause mortality (MH-OR for ET vs BS: 0.98 [0.80, 1.21], p = 0.88). A significantly higher rate of MALE was reported in participants treated with ET (MH-OR: 1.44 [1.05, 1.98], p = 0.03); in diabetes subgroup analysis showed no differences between-group for this outcome (MH-OR: 1.34 [0.76, 2.37], p = 0.30). Operative duration and length of hospital stay were significantly shorter for ET (WMD: - 101.53 [- 127.71, - 75.35] min, p < 0.001, and, - 4.15 [- 5.73, - 2.57] days, p < 0.001 =, respectively). ET was associated with a significantly lower risk of any SAE within 30 days in comparison with BS (MH-OR: 0.60 [0.42, 0.86], p = 0.006). ET was associated with a significantly higher risk of reintervention (MH-OR: 1.57 [1.10, 2.24], p = 0.01). No significant between-group differences were reported for ulcer healing (MH-OR: 1.19 [0.53, 2.69], p = 0.67), although time to healing was shorter (- 1.00 [0.18, 1.82] months, p = 0.02) with BS. No differences were found in terms of quality of life and pain. ABI at the end of the study was reported by 7 studies showing a significant superiority of BS in comparison with ET (WMD: 0.09[0.02; 0.15] points, p = 0.01). The results of this meta-analysis showed no clear superiority of either ET or BS for the treatment of infrainguinal PAD also in diabetic patients. Further high-quality studies are needed, focusing on clinical outcomes, including pre-planned subgroup analyses on specific categories of patients, such as those with diabetes and detailing multidisciplinary team approach and structured follow-up.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

BACKGROUND

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear.

METHODS

A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency.

RESULTS

From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE.

CONCLUSIONS

Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Amputation Rates and Associated Social Determinants of Health in the Most Populous US Counties

Importance

Social Determinants of Health (SDOH) have been found to be associated with health outcome disparities in patients with peripheral artery disease (PAD). However, the association of specific components of SDOH and amputation has not been well described.

Objective

To evaluate whether individual components of SDOH and race are associated with amputation rates in the most populous counties of the US.

Design, Setting, and Participants

In this population-based cross-sectional study of the 100 most populous US counties, hospital discharge rates for lower extremity amputation in 2017 were assessed using the Healthcare Cost and Utilization Project State Inpatient Database. Those data were matched with publicly available demographic, hospital, and SDOH data. Data were analyzed July 3, 2022, to March 5, 2023.

Main outcome and Measures

Amputation rates were assessed across all counties. Counties were divided into quartiles based on amputation rates, and baseline characteristics were described. Unadjusted linear regression and multivariable regression analyses were performed to assess associations between county-level amputation and SDOH and demographic factors.

Results

Amputation discharge data were available for 76 of the 100 most populous counties in the United States. Within these counties, 15.3% were African American, 8.6% were Asian, 24.0% were Hispanic, and 49.6% were non-Hispanic White; 13.4% of patients were 65 years or older. Amputation rates varied widely, from 5.5 per 100 000 in quartile 1 to 14.5 per 100 000 in quartile 4. Residents of quartile 4 (vs 1) counties were more likely to be African American (27.0% vs 7.9%, P < .001), have diabetes (10.6% vs 7.9%, P < .001), smoke (16.5% vs 12.5%, P < .001), be unemployed (5.8% vs 4.6%, P = .01), be in poverty (15.8% vs 10.0%, P < .001), be in a single-parent household (41.9% vs 28.6%, P < .001), experience food insecurity (16.6% vs 12.9%, P = .04), or be physically inactive (23.1% vs 17.1%, P < .001). In unadjusted linear regression, higher amputation rates were associated with the prevalence of several health problems, including mental distress (β, 5.25 [95% CI, 3.66-6.85]; P < .001), diabetes (β, 1.73 [95% CI, 1.33-2.15], P < .001), and physical distress (β, 1.23 [95% CI, 0.86-1.61]; P < .001) and SDOHs, including unemployment (β, 1.16 [95% CI, 0.59-1.73]; P = .03), physical inactivity (β, 0.74 [95% CI, 0.57-0.90]; P < .001), smoking, (β, 0.69 [95% CI, 0.46-0.92]; P = .002), higher homicide rate (β, 0.61 [95% CI, 0.45-0.77]; P < .001), food insecurity (β, 0.51 [95% CI, 0.30-0.72]; P = .04), and poverty (β, 0.46 [95% CI, 0.32-0.60]; P < .001). Multivariable regression analysis found that county-level rates of physical distress (β, 0.84 [95% CI, 0.16-1.53]; P = .03), Black and White racial segregation (β, 0.12 [95% CI, 0.06-0.17]; P < .001), and population percentage of African American race (β, 0.06 [95% CI, 0.00-0.12]; P = .03) were associated with amputation rate.

Conclusions and Relevance

Social determinants of health provide a framework by which the associations of environmental factors with amputation rates can be quantified and potentially used to guide interventions at the local level.

Revascularization with BYCROSS atherectomy device- protocol of a prospective multicenter observational study

BACKGROUND

The BYCROSS™ device is a novel device intended for use in atherectomy of the peripheral arterial disease (PAD). With the BYCROSS™ atherectomy system, also prolonged calcifying lesions can be treated in a minimally invasive manner, which was previously reserved for bypass surgery. The aim of this study is to collect additional clinical data on safety and performance of the BYCROSS™ from patients undergoing revascularization of severely stenotic or occluded peripheral arterial vessels with the BYCROSS™.

METHODS AND DESIGN

This is an investigator-initiated national prospective multicenter observational study in patients with PAD. Sixty patients (20 per center) with PAD with stenosis higher than 80% or complete occlusion (de novo or recurrent stenosis) of vessels below the aortic bifurcation (min 3 mm vessel diameter) will be recruited. Three vascular surgery centers are participating in the study. The primary efficacy endpoint is procedural success, defined as passage of the occlusion through the BYCROSS device, and safety outcomes, explicated as freedom from device-related serious adverse events (SADEs). Secondary endpoints include primary and secondary patency rates, change in Rutherford classification, and freedom from amputation at 3 and 12 months.

DISCUSSION

The BYCROSS atherectomy system may be a novel device for the minimally invasive treatment of prolonged calcified lesions previously reserved for bypass surgery. This national prospective multicenter observational study could represent another step in demonstrating the efficancy and safety of this device for treatment of PAD.

TRIAL REGISTRATION

#DRKS00029947 (who.int). PROTOCOL APPROVAL ID: #22-0047(Ethics Committee at Ludwig-Maximilians-University Munich).

A national analysis of vascular surgery resident operative experience in peripheral artery disease

BACKGROUND

Endovascular and hybrid interventions have played an increasingly prominent role in the treatment of peripheral arterial disease (PAD) in the past decade. This shift has prompted concerns about the adequacy of open surgical training for current surgical residents. Moreover, the recent Best Surgical Therapy in Patients With Critical Limb Ischemia trial has further emphasized the importance of open surgical techniques in the treatment of peripheral arterial disease. The purpose of this study was to examine national temporal trends in peripheral operative volume among integrated vascular surgery residents.

METHODS

Data was obtained from the Accreditation Council for Graduate Medical Education national data reports for integrated vascular surgery residents. Case volumes for surgeon chief or surgeon junior cases were collected from academic years 2012 to 2013 and 2021 to 2022. Trends in case-mix and volume were evaluated using linear regression analysis.

RESULTS

The mean total vascular operative volume increased from 851.2 to 914.3 cases among graduating chief residents, with an annual growth of 8.5 ± 1.7 cases/year (R2 = 0.77; P < .0001). Major vascular case volume also increased at a rate of 5.7 ± 1.2 cases/year (R2 = 0.74; P < .001). Among operative categories, peripheral cases were the most frequent (n = 232.2 [26.6%]) and demonstrated the greatest annual growth (+8.0 ± 0.8 cases/year, R2 = 0.93; P < .001). No changes were seen in volume of open peripheral cases, including suprainguinal bypass (+0.1 ± 0.2 cases/year; R2 = 0.08; P = .40) or femoropopliteal bypass procedures (-0.1 ± 0.2 cases/year; R2 = 0.17; P = .20). Infrapopliteal bypass (+0.4 ± 0.1 cases/year; R2 = 0.48; P = .006), iliac/femoral endarterectomy (+1.3 ± 0.2 cases/year; R2 = 0.82; P < .001), and leg thromboembolectomy (+0.4 ± 0.1 cases/year; R2 = 0.64; P < .001) all demonstrated annual growth. For endovascular peripheral cases, aortoiliac revascularization (+3.4 ± 0.3 cases/year; R2 = 0.94; P < .001), femoropopliteal revascularization (+5.4 ± 0.2 cases/year; R2 = 0.98; P < .001), and tibioperoneal revascularization (+2.0 ± 0.2 cases/year; R2 = 0.92; P < .001) all increased in volume. Lower extremity amputations, including above-knee amputation (+0.6 ± 0.2 cases/year; R2 = 0.65; P < .001) and below-knee amputation (+0.9 ± 0.2 cases/year; R2 = 0.72; P < .001) also demonstrated an increase in volume.

CONCLUSIONS

Current graduating residents have higher open and endovascular case volumes for peripheral artery disease on a national level, despite the increasing popularity of endovascular techniques. Further studies are needed to identify how these trends may impact current vascular surgery milestones. These trends may also influence the rising interest in competency-based training programs.

Peripheral arterial disease treatment planning using noninvasive and invasive imaging methods

With the growing prevalence and mortality of peripheral arterial disease, preoperative assessment, risk stratification, and determining the correct indication for endovascular and open surgical procedures are essential for therapeutic decision-making. The effectiveness of interventional procedures is significantly influenced by the plaque composition and calcification pattern. Therefore, the identification of patients for whom endovascular treatment is the most appropriate therapeutic solution often remains a challenge. The most commonly used imaging techniques have their own limitations and do not provide findings detailed enough for specific, personalized treatment planning. Using state-of-the-art noninvasive and invasive imaging modalities, it is now possible to obtain a view, not only of the complex vascular anatomy and plaque burden of the lower extremity arterial system, but also of complex plaque structures and various pathologic calcium distribution patterns. In the future, as these latest advancements in diagnostic methods become more widespread, we will be able to obtain more accurate views of the plaque structure and anatomic complexity to guide optimal treatment planning and device selection. We reviewed the implications of the most recent invasive and noninvasive lower extremity imaging techniques and future directions.

The Vascular Quality Initiative assessment of the Bard Lifestent for the treatment of popliteal artery occlusive disease

OBJECTIVE

The Bard LifeStent self-expanding stent is approved for the treatment of occlusive disease involving the superficial femoral artery and proximal popliteal artery. We conducted a post-market trial of treatment of the popliteal artery above and below the knee (P1, P2, and P3 segments) within the Society for Vascular Surgery Vascular Quality Initiative (VQI) Peripheral Vascular Intervention registry.

METHODS

A single-arm, prospective trial was conducted at 29 VQI sites in the United States, enrolling 74 patients from November 2016 to May 2019. The primary safety outcome was freedom from major adverse events including device-/procedure-related mortality and major amputation at 1 year. The primary efficacy outcomes were freedom from target vessel revascularization and freedom from target lesion revascularization at 1 year. Secondary outcomes included lesion success; procedural success; primary, primary-assisted, and secondary patency; and sustained clinical (improvement in Rutherford class) and hemodynamic success (increase in ankle brachial index >0.10). Outcomes were assessed by Kaplan-Meier analysis. Arteriogram of patients undergoing target lesion revascularization were assessed for stent fracture by a core laboratory.

RESULTS

The mean age was 71 years, with 63.5% male and 55% with diabetes. The indication was claudication 28% and chronic limb-threatening ischemia in 72%. The superficial femoral artery-popliteal artery was stented in 38% and the popliteal artery alone in 62%. The majority of stents were placed in the P1 + P2 (39%) or P1 + P2 + P3 (37%) segments of the popliteal artery. The composite primary endpoint of freedom from major adverse events was 82% and 74% at 1 and 2 years, respectively. Freedom from mortality was 100% and 97%, and freedom from major amputation was 100% and 90% at 1 and 12 months, with all deaths and major amputations occurring in patients with chronic limb-threatening ischemia. freedom from target lesion revascularization was 86%, and freedom from target vessel revascularization was 84% at 12 months. At discharge, lesion treatment success was 99%, and procedural success was 82%. Primary patency was 80% and 72%, primary-assisted patency was 80% and 72%, and secondary patency was 89% and 82% at 12 and 24 months. Sustained clinical success was 98% and 95%, and sustained hemodynamic success was 100% and 79% at 12 and 24 months.

CONCLUSIONS

In this multi-center, registry-based, single-arm prospective study the Bard LifeStent self-expanding stent demonstrated favorable performance in the challenging anatomy of the P2 and P3 popliteal segment. Post-market studies for label expansion of peripheral vascular intervention devices can be successfully conducted within the Society for Vascular Surgery VQI registry.

Predicting outcomes following open revascularization for aortoiliac occlusive disease using machine learning

OBJECTIVE

Open surgical treatment options for aortoiliac occlusive disease carry significant perioperative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following open aortoiliac revascularization.

METHODS

The National Surgical Quality Improvement Program (NSQIP) targeted vascular database was used to identify patients who underwent open aortoiliac revascularization for atherosclerotic disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. The 30-day secondary outcomes were individual components of the primary outcome, major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death), individual components of MACE, wound complication, bleeding, other morbidity, non-home discharge, and unplanned readmission. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Variable importance scores were calculated to determine the top 10 predictive features. Performance was assessed on subgroups based on age, sex, race, ethnicity, symptom status, procedure type, and urgency.

RESULTS

Overall, 9649 patients were included. The primary outcome of 30-day MALE or death occurred in 1021 patients (10.6%). Our best performing prediction model for 30-day MALE or death was XGBoost, achieving an AUROC of 0.95 (95% confidence interval [CI], 0.94-0.96). In comparison, logistic regression had an AUROC of 0.79 (95% CI, 0.77-0.81). For 30-day secondary outcomes, XGBoost achieved AUROCs between 0.87 and 0.97 (untreated loss of patency [0.95], major reintervention [0.88], major amputation [0.96], death [0.97], MACE [0.95], myocardial infarction [0.88], stroke [0.93], wound complication [0.94], bleeding [0.87], other morbidity [0.96], non-home discharge [0.90], and unplanned readmission [0.91]). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. The strongest predictive feature in our algorithm was chronic limb-threatening ischemia. Model performance remained robust on all subgroup analyses of specific demographic/clinical populations.

CONCLUSIONS

Our ML models accurately predict 30-day outcomes following open aortoiliac revascularization using preoperative data, performing better than logistic regression. They have potential for important utility in guiding risk-mitigation strategies for patients being considered for open aortoiliac revascularization to improve outcomes.

Primary results of the SAVAL randomized trial of a paclitaxel-eluting nitinol stent versus percutaneous transluminal angioplasty in infrapopliteal arteries

BACKGROUND

Effective and durable options for infrapopliteal artery revascularization for patients with chronic limb-threatening ischemia (CLTI) are limited.

METHODS

The SAVAL trial is a prospective, multicenter, randomized trial of patients with CLTI and infrapopliteal artery lesions with total lesion length ⩽ 140 mm, stenosis ⩾ 70%, and Rutherford category 4-5 assigned 2:1 to treatment with the SAVAL self-expandable paclitaxel drug-eluting stent (DES) or percutaneous transluminal angioplasty (PTA) with an uncoated balloon. The primary effectiveness endpoint was primary vessel patency (i.e., core lab-adjudicated duplex ultrasound-based flow at 12 months in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion). The primary safety endpoint was the 12-month major adverse event (MAE)-free rate; MAEs were defined as a composite of above-ankle index limb amputation, major reintervention, and 30-day mortality. The endpoints were prespecified for superiority (effectiveness) and noninferiority (safety) at a one-sided significance level of 2.5%.

RESULTS

A total of 201 patients were enrolled and randomly assigned to treatment (N = 130 DES, N = 71 PTA). Target lesion length was 68.1 ± 35.2 mm for the DES group and 68.7 ± 49.2 mm for the PTA group, and 31.0% and 27.6% of patients, respectively, had occlusions. The 12-month primary patency rates were 68.0% for the DES group and 76.0% for the PTA group (Psuperiority = 0.8552). The MAE-free rates were 91.6% and 95.3%, respectively (Pnoninferiority = 0.0433).

CONCLUSION

The SAVAL trial did not show benefit related to effectiveness and safety with the nitinol DES compared with PTA in infrapopliteal artery lesions up to 140 mm in length. Continued innovation to provide optimal treatments for CLTI is needed. (ClinicalTrials.gov Identifier: NCT03551496).

Investigation of center-specific saphenous vein utilization rates in femoral popliteal artery bypass and associated impact of conduit on outcomes

OBJECTIVE

The purpose of this study is to investigate variation in great saphenous vein (GSV) use among the various centers participating in the Vascular Quality Initiative infrainguinal bypass modules. Further, differences in outcomes in femoral-popliteal artery bypass with single segment GSV conduit vs prosthetic conduit will be documented. Center GSV use rate impact on outcomes will be investigated.

METHODS

Primary exclusions were patients undergoing redo bypass, urgent or emergent bypass, and those in whom prosthetic graft was used while having undergone prior coronary artery bypass grafting. The distribution of GSV use across the 260 centers participating in Vascular Quality Initiative infrainguinal bypass module was placed into histogram and variance in mean GSV use evaluated with analysis of variance analysis. Centers that used GSV in >50% of bypasses were categorized as high use centers and centers that used the GSV in <30% of cases were categorized as low use centers. Baseline differences in patient characteristics and comorbidities in those undergoing bypass with GSV vs prosthetic conduit were analyzed with χ2 testing and the Student t test, as were those undergoing treatment in high vs low use centers. Multivariable time-dependent Cox regression analyses were then performed for the primary outcomes of major amputation ipsilateral to the operative side and mortality in long-term follow-up. High vs low use center was a dichotomous variable in these regressions. Secondary outcomes of freedom from graft infection and freedom from loss of primary patency were performed with Kaplan-Meier analysis.

RESULTS

Among centers with >50 patients meeting inclusion criteria for this study, GSV use ranged from 15% to 93% (analysis of variance P < .001). When considering all centers irrespective of number of patients, the range was 0% to 100%. On Kaplan-Meier analysis, GSV conduit use was associated with improved freedom from loss of primary or primary assisted patency, improved freedom from major amputation after index hospitalization, improved freedom from graft infection after the index hospitalization, and improved freedom from mortality in long-term follow-up (log-rank P < .001 for all four outcomes). Both low use center (hazard ratio, 1.35; P < .001) and prosthetic graft use (hazard ratio, 1.24; P < .001) achieved multivariable significance as risks for mortality in long-term follow-up. Other variables with a multivariable mortality association are presented in the manuscript. Low use center and prosthetic bypass were significant univariable but not multivariable risks for major amputation after index hospitalization.

CONCLUSIONS

There is remarkably wide variation in GSV use for femoral popliteal artery bypass among various medical centers. GSV use is associated with enhanced long-term survival as well as freedom from loss of bypass patency and graft infection. The data herein indicate institutional patterns of prosthetic conduit choice, which has the potential to be altered to enhance outcomes.

A scoping review of female sex-related outcomes after endovascular intervention for lifestyle-limiting claudication and chronic limb-threatening ischemia

Peripheral arterial disease (PAD) is on the rise, with a growing prevalence in an aging population and increasing rates of diabetes. Chronic limb-threatening ischemia poses a significant risk of limb loss. PAD is common in females, particularly after menopause, with a 35% prevalence rate in females older than 65 years. Studies have suggested that females have inferior outcomes compared with men after endovascular revascularization for PAD. With the rising utilization of endovascular interventions for the treatment of PAD, we sought to perform a review of sex-based outcomes of peripheral endovascular interventions for the treatment of symptomatic PAD. A scoping literature review was conducted to evaluate outcomes in females patients undergoing endovascular peripheral interventions for PAD. Eligibility criteria included studies focusing on adult females with lifestyle-limiting claudication or chronic limb-threatening ischemia who underwent endovascular intervention. Various endovascular procedures were considered and outcomes of interest included mortality, amputations, reinterventions, bleeding complications, and major adverse cardiac events. A systematic search was conducted in PubMed, Embase, Web of Science, and Cochrane Library databases. Sixteen studies were included in the review. Females patients undergoing endovascular interventions were associated with bleeding complications, higher rates of reintervention, and a risk of nonfatal strokes. However, females sex was not linked to higher rates of amputation or conclusively higher mortality rates post intervention. The comprehensive scoping review reveals important sex-related disparities in outcomes after endovascular procedures for symptomatic PAD. Females patients have been reported to experience worse outcomes in terms of reinterventions and bleeding complications. These findings emphasize the need for future trials focusing specifically on females patients to develop sex-inclusive treatment recommendations for advanced PAD.

Valvulotomy of the great saphenous vein in ex situ non-reversed and in situ setting: a multicenter post-market study to assess the safety and efficacy of the AndraValvulotome™"

PURPOSE

To evaluate the safety and technical success of the AndraValvulotome™ device (Andramed GmbH, Reutlingen, Germany) in patients with peripheral arterial disease (PAD) requiring bypass surgery using the great saphenous vein (GSV) as graft.

METHODS

This was a multicenter, post-market observational study conducted in 2021 in 11 German centers. Safety and efficacy data were prospectively collected and analyzed. Primary endpoints were the absence of device-related serious adverse events until 30 ± 7 days follow-up, the clinical efficacy of valvulotomy, which was defined as pulsatile blood flow in the bypass and the number of insufficiently destroyed vein valves. Secondary endpoints were the number of valvulotomy passages, the primary patency rate of the venous bypass (determined by a color-duplex sonography showing a normal blood flow through the bypass and absence of stenosis or occlusion), and the primary technical success defined as the absence of product-specific (serious) adverse events and clinical efficacy.

RESULTS

Fifty-nine patients were enrolled. The mean age of the patients was 71 years (46-91), and 74.6% were males. The vein material used for bypass grafting had a median length of 47.5 cm (range 20-70 cm) with a median diameter of 5.0 mm (range 3-6 mm) and 4.0 mm (range 2-6 mm) in the proximal and distal segments, respectively. The technical success rate was 96.6%. The primary patency rate was 89.9% at 30 days follow-up. The clinical efficacy was rated as very good in 81% of patients, fair in 17%, and poor in 2%. Between 1 and 5 (average 2.9) valvulotome passages were performed. One product-related serious adverse event was recorded (bypass vein dissection).

CONCLUSION

The AndraValvulotome™ can be considered a safe and effective device to disrupt venous valves during in situ non-reversed bypass surgeries using GSV grafts in patients with PAD.

Angiographic and Clinical Impact of Novel Revascularization for Occluded Femoropopliteal Prosthetic Bypass Graft: A Combination of Surgical Thrombectomy and Drug-Coated Balloon Angioplasty

Background

Previous reports have revealed various endovascular intervention techniques for prosthetic femoropopliteal bypass occlusion (PFPBO); however, treatment for PFPBO remains challenging for most interventionalists and vascular surgeons because the procedure is complicated. Most of the reported techniques involve device implantation. In the present study, we performed a combination of surgical graft thrombectomy and drug-coated balloon angioplasty for PFPBO without implanting any additional devices. Furthermore, we determined the favorable long-term results of this treatment using follow-up angiography. Case Presentation. A 77-year-old man with a history of chronic kidney disease and coronary artery disease presented to our clinic with rest pain on his left leg. Seven years prior to the current consult, he underwent femoropopliteal bypass (FPB) surgery using a prosthetic graft due to in-stent occlusion of the left superficial femoral artery (SFA). Four years after surgery, a duplex ultrasound scan revealed stenosis of the proximal anastomosis site; hence, medical therapy was continued. On the current consult, diagnostic angiography revealed occlusion of the FPB and infrapopliteal vessels. In the first attempt at recanalization, the guidewire was unable to pass through the occluded SFA. Therefore, another technique was performed to revascularize the FPBO and infrapopliteal vessels. We obtained an angiography of the left leg after inserting the guiding sheath via the right common femoral artery (CFA). First, surgical thrombectomy using a Fogarty catheter via the exposed left CFA was performed. Following endovascular therapy via the right CFA, we performed drug-coated balloon angioplasty for anastomotic stenosis and recanalized occlusive infrapopliteal vessels. Restenosis was not observed on follow-up angiograms. On further follow-up angiography, there was notable regression of the residual stenosis at the proximal anastomosis of the prosthetic graft.

Conclusion

This novel revascularization strategy may be a viable treatment option for PFPBO.

Epigenetic Regulation of Angiogenesis in Peripheral Artery Disease

Peripheral arterial disease (PAD) represents a global health concern with a rising prevalence attributed to factors such as obesity, diabetes, aging, and smoking. Among patients with PAD, chronic limb-threatening ischemia (CLTI) is the most severe manifestation, associated with substantial morbidity and mortality. While revascularization remains the primary therapy for CLTI, not all patients are candidates for such interventions, highlighting the need for alternative approaches. Impaired angiogenesis, the growth of new blood vessels, is a central feature of PAD, and despite decades of research, effective clinical treatments remain elusive. Epigenetics, the study of heritable changes in gene expression, has gained prominence in understanding PAD pathogenesis. Here, we explore the role of epigenetic regulation in angiogenesis within the context of PAD, with a focus on long non-coding RNAs and fibroblast-endothelial cell transdifferentiation. Additionally, we discuss the interplay between metabolic control and epigenetic regulation, providing insights into potential novel therapeutic avenues for improving PAD treatments. This review aims to offer a concise update on the application of epigenetics in angiogenesis and PAD research, inspiring further investigations in this promising field.

Skeletal muscle regeneration failure in ischemic-damaged limbs is associated with pro-inflammatory macrophages and premature differentiation of satellite cells

BACKGROUND

Chronic limb-threatening ischemia (CLTI), a severe manifestation of peripheral arterial disease (PAD), is associated with a 1-year limb amputation rate of approximately 15-20% and substantial mortality. A key feature of CLTI is the compromised regenerative ability of skeletal muscle; however, the mechanisms responsible for this impairment are not yet fully understood. In this study, we aim to delineate pathological changes at both the cellular and transcriptomic levels, as well as in cell-cell signaling pathways, associated with compromised muscle regeneration in limb ischemia in both human tissue samples and murine models of CLTI.

METHODS

We performed single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients and from a murine model of CLTI. In both datasets, we analyzed gene expression changes in macrophage and muscle satellite cell (MuSC) populations as well as differential cell-cell signaling interactions and differentiation trajectories.

RESULTS

Single-cell transcriptomic profiling and immunofluorescence analysis of CLTI patient skeletal muscle demonstrated that ischemic-damaged tissue displays a pro-inflammatory macrophage signature. Comparable results were observed in a murine CLTI model. Moreover, integrated analyses of both human and murine datasets revealed premature differentiation of MuSCs to be a key feature of failed muscle regeneration in the ischemic limb. Furthermore, in silico inferences of intercellular communication and in vitro assays highlight the importance of macrophage-MuSC signaling in ischemia induced muscle injuries.

CONCLUSIONS

Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and a murine CLTI model, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Minor amputation after revascularization in chronic limb-threatening ischemia: What is the optimal timing?

OBJECTIVES

Patients with chronic limb-threatening ischemia (CLTI) have a high risk of lower limb amputation and loss of walking independence. Minor amputations play a key role in ensuring walking independence and they represent a challenge in terms of timing and level for vascular surgeons. A major cause of re-amputation is a defect in wound healing and a possible predictor of re-amputation for non-healing wounds could be the incorrect timing of minor amputation after revascularization. The lack of evidence in the literature leads to a wide variability of choices in clinical practice. The purpose of this study was to try to find the optimal timing analysing the risk of re-amputation in CLTI patients who have undergone successful revascularization and minor amputation focussing on timing of minor amputation.

METHODS

We conducted a single centre retrospective analysis on a cohort of 151 patients consecutively admitted to our hospital for CLTI (Rutherford 5) between January 2014 and April 2022. All the enrolled patients underwent successful revascularization of lower limbs and a minor amputation for dry acral necrosis. The characteristics of the patients and the revascularization procedures were collected and analysed. Patients were divided into two groups based on the timing of minor amputation performed before (group 1) or after the day (group 2) that best predicts the risk of re-amputation according to a Receiver Operating Characteristic (ROC) curve analysis. The primary outcome of this study was the risk of re-amputation during the first 60 days of follow-up after a primary minor amputation, with revascularization still effective. The impact of the timing of minor amputation after revascularization, the type of revascularization and the presence of risk factors known to prolong the wound healing process were evaluated in a uni- and multi-variable logistic regression model.

RESULTS

Systemic hypertension, and type of revascularization (i.e. open vs endovascular) were independent predictors of the risk of re-amputation at 60 days (HR 4.26, 95% CI 1.30-14.04, p = .017 and HR 2.35, 95% CI 1.16-4.78, p = .018, respectively). Moreover, time ≤14 days between revascularization and first amputation was associate with a clear, albeit not statistically significant, trend toward increased risk of re-amputation (HR 2.09, 95% CI 0.97-4.51, p = .06).

CONCLUSIONS

In a cohort of patients who underwent a successful revascularization for CLTI and a minor amputation for dry gangrene in the first 14 days after revascularization, a higher -although not significant-risk of re-amputation was reported. In this cohort of patients, a delayed demolitive procedure should be considered to allow better tissue perfusion and to reduce the risk of re-amputation.