Endovascular treatment of TransAtlantic Inter-Society Consensus II D femoropopliteal lesions in patients with critical limb ischemia

Construction of prediction models for novel subtypes in patients with arteriosclerosis obliterans undergoing endovascular therapy: an unsupervised machine learning study

BACKGROUND

Arteriosclerosis obliterans (ASO) is a chronic arterial disease that can lead to critical limb ischemia. Endovascular therapy is increasingly used for limb salvage in ASO patients, but the outcomes vary. The development of prediction models using unsupervised machine learning may lead to the identification of novel subtypes to guide patient prognosis and treatment.

METHODS

This retrospective study analyzed clinical data from 448 patients with ASOs who underwent endovascular therapy. Unsupervised machine learning algorithms were employed to identify subgroups. To validate the precision of the clustering outcomes, an analysis of the postoperative results of the clusters was conducted. A prediction model was constructed using binary logistic regression.

RESULTS

Two distinct subgroups were identified by unsupervised machine learning and characterized by differing patterns of clinical features. Patients in Cluster 2 had significantly worse conditions and prognoses than those in Cluster 1. For the novel ASO subtypes, a nomogram was developed using six predictive factors, namely, platelet count, ankle brachial index, Rutherford category, operation method, hypertension, and diabetes status. The nomogram achieved excellent discrimination for predicting membership in the two identified clusters, with an area under the curve of 0.96 and 0.95 in training cohort and internal test cohort.

CONCLUSION

This study demonstrated that unsupervised machine learning can reveal novel phenotypic subgroups of patients with varying prognostic risk who underwent endovascular therapy. The prediction model developed could support clinical decision-making and risk counseling for this complex patient population. Further external validation is warranted to assess the generalizability of the findings.

Randomized clinical Trial Comparing drug Eluting Stent Zilver PTX® Versus Bare Metal Stent Zilver Flex® for Treatment of Lesions in Femoral and Popliteal Arteries in Chronic Limb Threatening Ischemia

OBJECTIVE

Drug eluting stents (DES) might improve the results of stenting in the femoropopliteal (FP) segment, but randomized data between DES and BMS in the treatment of patients with chronic limb threatening ischemia (CLTI) is lacking. The aim of this study was to perform a randomized comparison, between DES and bare metal stent (BMS) implantation in a subgroup of CLTI patients with lesions in the superficial femoral artery (SFA) and the P1-P2 portion of the popliteal artery.

METHODS

Patients presenting with CLTI scheduled for endovascular treatment of FP lesions were randomly assigned by blinded envelopes 1:1 in a single blinded, parallel group design to DES or BMS after lesion crossing. Primary endpoints were target lesion revascularization (TLR) at 12 and 24 months and primary patency at 12 and 24 months. Secondary endpoints were technical success (TS), clinical success, secondary patency at 12 and 24 months, limb salvage, serious adverse events (SAE) at 24 month and survival at five years.

RESULTS

A total of 48 CLTI patients and 49 limbs, were enrolled, 22 in the BMS group and 27 in the DES group. Demographics, comorbidities, and Rutherford class were similar in both treatment arms. The overall rate of total occlusions was 96% and the corresponding overall median lesion length was 240 mm. No patients were lost to follow up. No significant differences were detected between groups regarding TLR and primary patency. The overall primary patency at 12 and 24 months was 42.9% and 36.7% respectively and the overall freedom from TLR was 67.3% and 61.2% respectively. The results in the two groups were also similar regarding secondary outcomes.

CONCLUSIONS

This single centre, randomized study could not demonstrate superiority of DES compared to BMS when treating long FP lesions in patients with CLTI but was limited by insufficient patient inclusion.

Systematic Review and Meta-analysis of Clinical Outcomes After Endovascular Treatment in Patients With Femoropopliteal Lesions Greater Than 150 mm

OBJECTIVE

Indications for endovascular treatment of femoropopliteal (FP) lesions have steadily increased over the past decade. Accordingly, the number of devices has also increased but the choice of the best endovascular treatment remains to be defined. The aim of this meta-analysis was to summarize all studies investigating endovascular treatment of FP lesions greater than 150 mm from 2010 to 2021.

METHODS

Articles were searched using PubMed, Scopus, and Cochrane. Included studies were randomized controlled trials (RCTs), cohort studies, and case series (prospective and retrospective) that evaluated any endovascular procedure in patients with long FP lesions classified TASC (Trans-Atlantic Inter-Society Consensus document II on management of peripheral arterial disease) C and/or D, and a mean length >150 mm, primary outcome had to be the 1-year primary patency. Overall estimate of primary patency, secondary patency, and freedom from target lesion revascularization (TLR) at 1 year depending on the different devices were investigated. The meta-analysis was conducted following the requirements of the MOOSE (Meta-analysis of Observational Studies in Epidemiology) checklist.

RESULTS

Forty-four papers comprising 4847 patients and 5282 treated limbs were included. Mean lesions length ranged from 150.5 to 330 mm. The pooled 1-year primary and secondary patencies, and freedom from TLR rates were 0.71 (95% CI: 0.67-0.74), 0.87 (95% CI: 0.83-0.91), and 0.79 (95% CI: 0.74-0.84), respectively. Primary permeability at 1 year were 0.68 (95% CI: 0.62-0.73), 0.67 (95% CI: 0.60-0.74), 0.74 (95% CI: 0.64-0.84), and 0.83 (95% CI: 0.78-0.88) for bare metal stents, covered stents (CSs), drug-eluting stents, and drug-coated balloons (DCBs), respectively. Lesions treated with DCB had the highest 1-year primary patency rate.

CONCLUSIONS

At 1-year, endovascular procedures for FP lesions greater than 150 mm obtain satisfactory results. High primary patency rates were obtained with drug-coated devices, while CSs obtained less favorable results. Randomized studies comparing different devices in the treatment of long FP lesions remain necessary to determine the most optimal approach for the management of these patients.

CLINICAL IMPACT

This paper highlights on the one hand the satisfactory results of endovascular treatment on complex femoropopliteal lesions formerly reserved for conventional surgery. On the other hand, among the available devices, paclitaxel-eluting devices seem to show superior results which should make them recommended as first-line treatment.

A Systematic Review and Meta-Analysis on Sex-Based Disparities in Patients with Chronic Limb Threatening Ischemia Undergoing Revascularization

BACKGROUND

This systematic review and meta-analysis sought to describe the prognostic implications of sex on the clinical outcomes of patients undergoing interventions for chronic limb threatening ischemia (CLTI).

METHODS

Studies were systematically searched across 7 databases from inception to August 25, 2021 and rerun on October 11, 2022. Studies focusing on patients with CLTI undergoing open surgery, endovascular treatment (EVT), or hybrid procedures were included if sex-based differences were associated with a clinical outcome. Two independent reviewers screened studies for inclusion, extracted data, and assessed risk of bias using the Newcastle-Ottawa scale. Primary outcomes included inpatient mortality, major adverse limb events (MALE), and amputation-free survival (AFS). Meta-analyses were performed using random effects models and reported pooled odds ratio (pOR) and 95% confidence interval (CI).

RESULTS

A total of 57 studies were included in the analysis. A meta-analysis of 6 studies demonstrated that female sex was associated with statistically higher inpatient mortality compared to male sex undergoing open surgery or EVT (pOR, 1.17; 95% CI: 1.11-1.23). Female sex also demonstrated a trend toward increased limb loss in those undergoing EVT (pOR, 1.15; 95% CI: 0.91-1.45) and open surgery (pOR 1.46; 95% CI: 0.84-2.55). Female sex also had a trend toward higher MALE (pOR, 1.06; 95% CI, 0.92-1.21) in 6 studies. Finally, female sex had a trend toward worse AFS (pOR, 0.85; 95% CI, 0.70-1.03) in 8 studies.

CONCLUSIONS

Female sex was significantly associated with higher inpatient mortality and a trend toward higher MALE following revascularization. Female sex trended toward worse AFS. The reasons for these disparities are likely multifaceted on patient, provider, and systemic levels and should be explored to identify solutions for decreasing these health inequities across this vulnerable patient population.

Endovascular Revascularization and Outcomes of Critical Limb-Threatening Ischemia in Trinidad and Tobago: The EVENT Pilot Study-Challenges in a Limited-Resource, Caribbean Setting

INTRODUCTION

This retrospective study investigated major adverse limb events (MALE) and mortality outcomes in critical limb-threatening ischemia (CLTI) patients with tissue loss after an endovascular revascularization-first (EVR-1st) strategy.

METHODS

MALE and mortality were assessed in 157 consecutive patients with CLTI and tissue loss from June 2019 to June 2022 at the Eric Williams Medical Sciences Complex, Trinidad and Tobago.

RESULTS

157 patients underwent the EVR-1st strategy, of whom 20 were pivoted to immediate surgical revascularization (SR). Of the remaining 137 patients, successful EVR was achieved in 112, giving a procedural success of 82% and an all-comer overall success of 71%. The mortality and MALE rates were 2.7% and 8.9% at 2 years, respectively. Males and patients with previous major amputations were at significantly higher risk for MALE (p values of 0.016 and 0.018, respectively). There was a statistically significant difference in successful EVR for both Rutherford-Baker (RB) 5 (minor) and RB 6 (major) classifications: 63 (56%) vs. 5 (20%) and 49 (44%) vs. 20 (80%), both with a p value of 0.01. There were no differences in successful EVR amongst Wound, Ischemia, Foot Infection (WIfI) clinical stages. There were no differences in successful EVR amongst the Trans-Atlantic Inter-Society Consensus (TASC II) classifications.

CONCLUSIONS

This study may prove clinically informative and applicable for an EVR-1st management strategy for high-risk patients with CLTI in a limited-resource, Caribbean setting.

TRIAL REGISTRATION NUMBER

NCT05547022 (retrospectively registered).

Mid-Term Outcomes of Endovascular Therapy for TASC II D Femoropopliteal Lesions with Critical Limb Ischaemia: A Retrospective Analysis

OBJECTIVE

This study evaluated the mid-term results of endovascular therapy (EVT) for Trans-Atlantic Inter-Society (TASC) II D femoropopliteal lesions in patients with critical limb ischaemia (CLI).

METHODS

Fifty-seven limbs of 54 patients with CLI due to TASC II D femoropopliteal lesions who underwent EVT at the First Hospital of Hebei Medical University were retrospectively analysed in single-centre, observational study. The patient characteristics, endovascular procedural details, freedom from target lesion revascularisation (TLR), patency rates, ulcer healing rate, and limb salvage rate were accessed.

RESULTS

The patients' mean age was 68.2 ± 8.2 years. All patients were treated by EVT. The final technical success rate was 98.2% (56/57). There were 23 cases of pain at rest, 18 cases of ulcer, and 15 cases of gangrene. The median length of the treated segment was 286 ± 42 mm (56/56) and the mean number of stents placed per patient was 2.0 ± 0.8 (49/56). The postoperative ankle-brachial index (ABI) was significantly higher than that of the preoperative ABI (P < 0.05). The perioperative complication rate was 10.7% (6/56). The re-stenosis or occlusion rate was 44.6% (25/56). The estimated rates of freedom from TLR at 1 year, 2 years, and 3 years were 86.8%, 67.0%, and 62.5%, respectively. Univariate analysis showed that predictors of freedom from TLR were the number of runoff vessels, length of the lesion, and complexity of the lesion, while predictors for re-stenosis or occlusion were the length and the complexity of the lesion. The ulcer healing rate was 93.8%. The limb salvage rates were 76.4%, 74.4%, and 70.9% at 1, 2, and 3 years after treatment, respectively.

CONCLUSIONS

The mid-term outcomes of EVT for TASC II D femoropopliteal lesions in patients with CLI indicated that this treatment approach is safe and effective, and is clinically applicable.

The Global Limb Anatomic Staging System is associated with outcomes of infrainguinal revascularization in chronic limb threatening ischemia

OBJECTIVE

The Global Limb Anatomic Staging System (GLASS) has been proposed to facilitate clinical decision-making regarding revascularization for chronic limb threatening ischemia (CLTI). The purpose of the present study was to define its relationship to the treatment outcomes in CLTI.

METHODS

Consecutive patients who had undergone peripheral angiography for rest pain or tissue loss from January 2017 to July 2019 at a tertiary referral center with a dedicated limb preservation program were reviewed. Subjects with significant aortoiliac disease, previous infrainguinal stenting or functioning bypass grafts, or GLASS stage 0 were excluded. The GLASS score was assigned from the preintervention angiography findings, and the treating surgeon determined the primary infrapopliteal target artery pathway for the limb at risk. The demographic data, procedural details, and clinical outcomes were analyzed.

RESULTS

The study cohort included 167 patients and 194 limbs, of which 175 of 194 limbs (90%) had presented with tissue loss and 149 of 182 limbs (83%) with WIfI (Wound, Ischemia and foot Infection) stage 3 or 4. The GLASS stage was GLASS 1 in 14%, GLASS 2 in 18%, and GLASS 3 in 68%. GLASS 3 anatomy was present in 85% of 52 limbs treated by bypass and 55% of 108 limbs treated by endovascular intervention (EVI; P < .001). Revascularization was not performed in 34 limbs, most of which were GLASS 3 (85%). Immediate technical failure for EVI (ie, failure to establish target artery pathway) occurred exclusively in the setting of GLASS 3 anatomy (n = 13; 22%). After a median follow-up of 10 months, limb-based patency after EVI was significantly lower in GLASS 3 than in GLASS 1 or 2 limbs (42% vs 59%; P = .018). GLASS 3 was associated with reduced major adverse limb events-free survival in both the EVI group (P = .002) and the overall revascularized cohort (P = .001). GLASS 3 was also associated with significantly reduced overall survival, amputation-free survival, and reintervention-free survival. In a Cox proportional hazards model, GLASS 3 (hazard ratio, 2.35; 95% confidence interval, 1.30-4.24; P = .005) and WIfI wound grade 3 (hazard ratio, 2.64; 95% confidence interval, 1.26-5.53; P = .010) were independent predictors of reduced major adverse limb events-free survival after revascularization.

CONCLUSIONS

GLASS stage 3 was strongly associated with major adverse clinical outcomes after revascularization in patients with CLTI.

Stents in the femoropopliteal territory: prevalence of fractures and their consequences

OBJECTIVE

Endovascular treatment for femoropopliteal arterial disease has made revascularization procedures less invasive, but the self-expanding stents used can suffer great wear in arteries with extreme mobility. To evaluate the prevalence of fractures in stents implanted in the femoropopliteal segment, to identify predisposing factors and consequences on arterial patency.

METHOD

between March and June 2019, thirty patients previously operated for femoropopliteal obstruction underwent stent X-rays in anteroposterior and lateral views to detect fractures and Doppler to analyze arterial patency.

RESULTS

we observed 12 cases with fractures (33.3%): 1 type I (2.8%), 3 type II (8.3%), 5 type III (13.9%), 3 type IV (8.3%) and no type V. According to the TASC II we had 1 in group B (8.3%), 6 in group C (50%) and 5 in group D (41.6%) p <0.004. The number of stents per limb was 3.1 (± 1.3) in cases of fracture versus 2.3 (± 1.3) in cases without fracture (p = 0.08). The extension was 274.17mm (± 100.94) in cases of fracture and 230.83mm (± 135.44) in cases without fracture (p = 0.29). On Doppler we had: 17 patients (47.2%) without stenosis, 9 patients (25%) with stenosis> 50% and 10 patients (27.8%) with occlusion (p = 0.37). There was no correlation between fracture and arterial obstruction (p = 0.33).

CONCLUSION

stent fractures are a frequent finding in the femoropopliteal area (33.3%), being more prevalent in cases of more advanced disease (C and D). There was no association between the finding of fracture and arterial obstruction.

Endovascular Intervention for the Treatment of Trans-Atlantic Inter-Society Consensus (TASC) D Femoropopliteal Lesions: A Systematic Review and Meta-Analysis

PURPOSE

Advancements in the endovascular treatment of femoropopliteal atherosclerotic lesions have led to treatment of more complex lesions, particularly long lesions. The aim of this study was to determine the meta-analytic primary patency and need for re-intervention among patients treated for very long lesions (>200 mm) at the femoropopliteal segment and to identify potential risk factors for loss of patency.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted, and the I-square was used to assess heterogeneity.

RESULTS

Fifty-one studies comprised of 3029 patients were included. The mean lesion length was 269 mm. The primary patency rate at 30 days, 6 m, 1-, 2- and 5-years of follow-up was 98%, 76%, 62%, 55%, and 39% respectively. The incidence of TLR was 16% at one year and 32% at two years. The secondary patency rate at 1, 2, 3 and 5 years was 85%, 71%, 64%, and 64% respectively. Heparin bonded ePTFE covered stents (69%) and paclitaxel eluting stents (73%) demonstrated higher 1-year primary patency rates than self-expanding nitinol stents (55%) or uncoated percutaneous transluminal angioplasty (PTA) with provisional stenting (54%). Lesions treated with a heparin bonded ePTFE covered stent had statistically significant higher odds of remaining patent at 1-year of follow-up (OR: 2.74; 95%CI: 1.63-4.61; p < 0.001) than lesions treated with BMS or PTA. Patients with long femoropopliteal lesions causing critical limb ischemia (CLI) developed restenosis or occlusion more often than patients treated for claudication (HR: 1.63; 95%CI: 1.06-2.49; p = 0.026) during an average follow-up of 26 months.

CONCLUSION

Primary stenting of femoropopliteal TASC D lesions using drug eluting stents or covered stents results in sustained patency over time. PTA or uncoated nitinol stents demonstrated lower patency rates. However, additional comparative studies are needed to determine the efficacy of newer technologies for the treatment of complex femoropopliteal lesions and provide evidence for the most optimal treatment approach.

Comparison of Bypass and Endovascular Intervention for Popliteal Occlusion with the Involvement of Trifurcation for Critical Limb Ischemia

BACKGROUND

The aim of this study is to analyze the technical aspects and outcomes of the treatment of occlusion of the popliteal artery with the involvement of the trifurcation treated with a bypass (open) and endovascular (endo) approach.

METHODS

Overall, 108 consecutive procedures were enrolled retrospectively. Patients were evaluated in 2 groups: the endo group (65 patients) and the open group (43 patients). Primary outcome were MALE (major adverse limb events), amputation-free survival, and early mortality (until 30 days). Secondary outcome was overall survival in 3 years. Inclusion criteria were Rutherford 4 and 5 and occlusion of the popliteal artery with the involvement of trifurcation and, at least, 1 infrapopliteal artery of runoff.

RESULTS

Technical success was achieved in 100% of patients in the open and 96.9% of patients in the endo group. Freedom from MALE was 73.5% and 68.5% for 1 and 3 years respectively for the endo group, and 84.3% and 77.2% respectively for the open group (P = 0.413). Considering the total number of major reinterventions executed until 3 years, the reinterventions was statistically more performed in the endo compared to the open group (P = 0.0459). Amputation-free survival for the endo group in 30 days, 1 year, and 3 years was 93.7%, 79.3%, and 66.0%, respectively, and the amputation-free survival for the open group was 88.4%, 77.4%, and 64.3% (P = 0.726). Early mortality was 9.3% for the open group and 1.5% for the endo group (P = 0.060). In 3 years, the overall survival was 75.1% in the open group and 84.3% in the endo group.

CONCLUSIONS

In 3 years, follow-up endovascular treatment of occlusion of the popliteal artery with the involvement of the trifurcation has similar time freedom from MALE compared to open approach. Overall and amputation-free survival was not different between the groups besides more reinterventions in patients who underwent endovascular approach.