Editor's Choice - Infra-inguinal Endovascular Revascularisation and Bypass Surgery for Chronic Limb Threatening Ischaemia: a Retrospective European Multicentre Cohort Study with Propensity Score Matching

Impact of Bypass Conduit and Early Technical Failure on Revascularization for Chronic Limb-Threatening Ischemia

BACKGROUND

The optimal strategy for lower extremity revascularization (surgical bypass versus endovascular intervention) in patients with chronic limb-threatening ischemia (CLTI) is unclear. We examined the effectiveness of open surgical bypass using single-segment great saphenous vein conduit (SSGSV), alternative conduits (AC), or endovascular interventions (ENDO) among patients with CLTI deemed acceptable for either open surgical bypass or ENDO treatment.

METHODS

This was a planned as-treated analysis of the multicenter BEST-CLI (Best Endovascular Versus Best Surgical Therapy in Patients With Critical Limb Ischemia) randomized controlled trial comparing open surgical bypass and ENDO for CLTI due to infrainguinal peripheral artery disease. Outcomes were tabulated based on the initial revascularization received: SSGSV bypass, AC bypass, and ENDO. Analyses were performed for all treated patients and then excluding those who experienced early technical failure. Multivariable Cox regression models were used. End points included the primary trial outcome (major adverse limb event [MALE] or all-cause death), major amputation, MALE at any time or perioperative (30-day) death, reintervention-amputation-death, and all-cause mortality.

RESULTS

Among 1780 patients with CLTI, treatments received included SSGSV bypass (n=621), AC bypass (n=236), and ENDO (n=923) procedures. There were no significant differences in 30-day mortality, major adverse cardiovascular events, or serious adverse events; subjects treated with ENDO experienced greater MALE within 30 days (13.1% versus 2.7%, 3% for SSGSV, AC; P<0.001). On risk-adjusted analysis, SSGSV bypass was associated with reduced MALE or all-cause death (hazard ratio, 0.65 [95% CI, 0.56-0.76]; P<0.001), major amputation (hazard ratio, 0.70 [95% CI, 0.52-0.94]; P=0.017), MALE or perioperative death (hazard ratio, 0.51 [0.41-0.62]; P<0.001), and reintervention-amputation-death (hazard ratio, 0.69 [95% CI, 0.61-0.79]; P<0.001). AC bypass was associated with reduced MALE or perioperative death and reintervention-amputation-death compared with ENDO. Significant benefits of SSGSV over ENDO remained when excluding patients who experienced early technical failure. There were no significant differences in long-term mortality by initial treatment received. When analyzed by the level of disease treated, the improved outcomes of SSGSV were greatest among patients who underwent femoropopliteal revascularization.

CONCLUSIONS

Analysis of as-treated outcomes from the BEST-CLI trial demonstrates the safety and clinical superiority of bypass with SSGSV among patients with CLTI who were deemed suitable for either open surgical bypass or ENDO revascularization. Assessment of great saphenous vein quality should be incorporated into the evaluation of patients with CLTI who are surgical candidates.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02060630 and NCT02060630.

Contemporary Outcomes of Infrainguinal Vein Bypass Surgery for Chronic Limb-Threatening Ischaemia: A Two-Centre Cross-Sectional Study

Background/Objectives: Chronic limb-threatening ischaemia (CLTI) is a significant life and limb-threatening condition. Two recent seminal trials, BEST-CLI and BASIL-2, have provided seemingly conflicting results concerning the optimal treatment modality for patients with CLTI. We sought to investigate the outcomes of patient undergoing infrainguinal bypass at two centres in Aotearoa New Zealand. Methods: A cross-sectional retrospective review of all patients who underwent infrainguinal bypass grafting for CLTI at Auckland City Hospital and Waikato Hospital between January 2020 and December 2021 was performed. The primary outcome was a composite of death, above-ankle amputation, and major limb reintervention. The secondary outcome was minor limb reintervention. Kaplan-Meier survival analysis was performed to determine time to the primary and secondary endpoints. Demographic factors were examined using the log-rank test to examine the effect on the outcome. Results: One hundred and nineteen patients who underwent infrainguinal bypass for CLTI in the study period were identified. Of these, 93 patients had a bypass with ipsilateral or contralateral GSV. The median follow-up time was 1.85 years. The most common indication for surgery was tissue loss (69%, n = 63), with the most common distal bypass target being the below-knee popliteal artery (45%, n = 41). The primary composite outcome occurred in 42.8% of the cohort (n = 39). Death was the most common component of the primary outcome (26%, n = 24). Male sex (HR 0.48, 95% CI 0.26-0.88, p = 0.018) and statin use (HR 0.49, 95% CI 0.24-0.98, p = 0.044) were independent predictors of protection from the composite outcome on multivariate analysis. Dialysis dependence (HR 3.32, 95% CI 1.23-8.99, p = 0.018) was an independent predictor for patients meeting the composite outcome. Conclusions: This study's results are consistent with the published outcomes of BEST-CLI. The patient cohorts examined, anatomical disease patterns, and conduit use may explain some of the differences observed between this study, BEST-CLI and BASIL-2. Further work is required to define the specific patient populations who will benefit most from an open surgical or endovascular first approach to the management of CLTI.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia is defined as ischemic rest pain or tissue loss (eg, ulceration/gangrene) that has been present for greater than 2 weeks. Workup includes a careful history, physical examination focused on evaluation of pulses and wounds, lower extremity noninvasive vascular studies (eg, ankle-brachial indices, toe pressures), saphenous vein mapping, and imaging of the lower extremity arterial anatomy (eg, computed tomography, magnetic resonance, or subtraction angiography) if a revascularization intervention is planned.

Infra-inguinal bypass surgery vs endovascular revascularization for chronic limb-threatening ischemia in average- and high-risk patients

OBJECTIVE

This study aimed to evaluate treatment outcomes after bypass surgery or endovascular therapy (EVT) in average- and high-risk patients with chronic limb-threatening ischemia (CLTI).

METHODS

We retrospectively analyzed multicenter data of patients who underwent infra-inguinal revascularization for CLTI between 2015 and 2022. A high-risk patient was defined as one with estimated 30-day mortality rate ≥5% or 2-year survival rate ≤50%, as determined by the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) calculator. The amputation-free survival (AFS), limb salvage (LS), wound healing, and 30-day mortality were compared separately for the average- and high-risk patients between the bypass and EVT with propensity score matching.

RESULTS

We analyzed 239 and 31 propensity score-matched pairs in the average- and high-risk patients with CLTI. In the average-risk patients, the 2-year AFS and LS rates were 78.1% and 94.4% in the bypass group and 63.0% and 87.7% in the EVT group (P < .001 and P = .007), respectively. The 1-year wound healing rates were 88.6% in the bypass group and 76.8% in the EVT group, respectively (P < .001). The 30-day mortality was 0.8% in the bypass surgery and 0.8% in the EVT group (P = .996). In the high-risk patients, there was no differences in the AFS, LS, and wound healing between the groups (P = .591, P = .148, and P = .074). The 30-day mortality was 3.2% in the bypass group and 3.2% in the EVT group (P = .991).

CONCLUSIONS

Bypass surgery is superior to EVT with respect to the AFS, LS, and wound healing in the average-risk patients. EVT is a feasible first-line treatment strategy for high-risk patients with CLTI undergoing revascularization, based on the lack of significant differences in the 2-year AFS rate, between the bypass surgery and EVT cohorts.

Relevance of BEST-CLI trial endpoints in a tertiary care limb preservation program

OBJECTIVE

Major adverse limb event-free survival (MALE-FS) differed significantly by initial revascularization approach in the BEST-CLI randomized trial. The BEST-CLI trial represented a highly selected subgroup of patients seen in clinical practice; thus, we examined the endpoint of MALE-FS in an all-comers tertiary care practice setting.

METHODS

This is a single-center retrospective study of consecutive, unique patients who underwent technically successful infrainguinal revascularization for chronic limb-threatening ischemia (2011-2021). MALE was major amputation (transtibial or above) or major reintervention (new bypass, open bypass revision, thrombectomy, or thrombolysis).

RESULTS

Among 469 subjects, the mean age was 70 years, and 34% were female. Characteristics included diabetes (68%), end-stage renal disease (ESRD) (16%), Wound, Ischemia, and foot Infection (WIfI) stage 4 (44%), Global Limb Anatomic Staging System (GLASS) stage 3 (62%), and high pedal artery calcium score (pMAC) (22%). Index revascularization was autogenous vein bypass (AVB) (30%), non-autogenous bypass (NAB) (13%), or endovascular (ENDO) (57%). The composite endpoint of MALE or death occurred in 237 patients (51%) at a median time of 189 days from index revascularization. In an adjusted Cox model, factors independently associated with MALE or death included younger age, ESRD, WIfI stage 4, higher GLASS stage, and moderate-severe pMAC, whereas AVB was associated with improved MALE-FS. Freedom from MALE-FS, MALE, and major amputation at 30 days were 90%, 92%, and 95%; and at 1 year were 63%, 70%, and 83%, respectively. MALE occurred in 144 patients (31%) and was associated with ESRD, WIfI stage, GLASS stage, pMAC score, and index revascularization approach. AVB had superior durability, with adjusted 2-year freedom from MALE of 72%, compared with 66% for ENDO and 51% for NAB. Within the AVB group, spliced vein conduit had higher MALE compared with single-segment vein (hazard ratio, 1.8; 95% confidence interval, 0.9-3.7; P = .008 after inverse propensity weighting), but there was no statistically significant difference in major amputation. Of the 144 patients with any MALE, the first MALE was major reintervention in 47% and major amputation in 53%. Major amputation as first MALE was associated with non-AVB index approach. Indications for major reintervention were symptomatic stenosis/occlusion (54%), lack of clinical improvement (28%), asymptomatic graft stenosis (16%), and iatrogenic events (3%). Conversion to bypass occurred after 6% of ENDO cases, two-thirds of which involved distal bypass targets at the ankle or foot.

CONCLUSIONS

In this consecutive, all-comers cohort, disease complexity was associated with procedural selection and MALE-FS. AVB independently provided the greatest MALE-FS and freedom from MALE and major amputation. Compared with the BEST-CLI randomized trial, MALE after ENDO in this series was more frequently major amputation, with relatively few conversions to open bypass.

Appropriate care in chronic limb threatening ischemia: A review of current evidence and outcomes

Chronic limb threatening ischemia (CLTI) poses a significant treatment challenge for vascular surgeons, interventionalists, podiatrists, and associated medical specialists. The evidence for what constitutes appropriate care is rapidly evolving and new treatment options are in constant development. This review examines the current guidelines for CLTI care, as well as reported outcomes for multiple care strategies in this patient population, including revascularization and medical optimization. We performed a literature review of the PubMed database, reviewing articles that reported outcomes for CLTI care between 2000 and 2023, and described these outcomes as they relate to the current state of CLTI treatment. Significant data are still forthcoming regarding CLTI care, but widespread adoption of appropriate CLTI care is essential for the treatment of this vulnerable population.

Endovascular therapy versus bypass for chronic limb-threatening ischemia in a real-world practice

OBJECTIVE

The recent Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) study showed that bypass was superior to endovascular therapy (ET) in patients with chronic limb-threatening ischemia (CLTI) deemed suitable for either approach who had an available single-segment great saphenous vein (GSV). However, the superiority of bypass among those lacking GSV was not established. We aimed to examine comparative treatment outcomes from a real-world CLTI population using the Vascular Quality Initiative-Medicare-linked database.

METHODS

We queried the Vascular Quality Initiative-Medicare-linked database for patients with CLTI who underwent first-time lower extremity revascularization (2010-2019). We performed two one-to-one propensity score matchings (PSMs): ET vs bypass with GSV (BWGSV) and ET vs bypass with a prosthetic graft (BWPG). The primary outcome was amputation-free survival. Secondary outcomes were freedom from amputation and overall survival (OS).

RESULTS

Three cohorts were queried: BWGSV (N = 5279, 14.7%), BWPG (N = 2778, 7.7%), and ET (N = 27,977, 77.6%). PSM produced two sets of well-matched cohorts: 4705 pairs of ET vs BWGSV and 2583 pairs of ET vs BWPG. In the matched cohorts of ET vs BWGSV, ET was associated with greater hazards of death (hazard ratio [HR] = 1.34, 95% confidence interval [CI], 1.25-1.43; P < .001), amputation (HR = 1.30, 95% CI, 1.17-1.44; P < .001), and amputation/death (HR = 1.32, 95% CI, 1.24-1.40; P < .001) up to 4 years. In the matched cohorts of ET vs BWPG, ET was associated with greater hazards of death up to 2 years (HR = 1.11, 95% CI, 1.00-1.22; P = .042) but not amputation or amputation/death.

CONCLUSIONS

In this real-world multi-institutional Medicare-linked PSM analysis, we found that BWGSV is superior to ET in terms of OS, freedom from amputation, and amputation-free survival up to 4 years. Moreover, BWPG was superior to ET in terms of OS up to 2 years. Our study confirms the superiority of BWGSV to ET as observed in the BEST-CLI trial.