Infrapopliteal Stents:Overview and Unresolved Issues

Clinical Outcomes of Additional Below-The-Ankle Intervention Compared to Below-The-Knee Intervention Alone: A Post-Hoc Analysis of a Prospective Multicenter Study

PURPOSE

To investigate the clinical implication of additional below-the-ankle (BTA) intervention in patients with chronic limb-threatening ischemia (CLTI) undergoing below-the-knee (BTK) intervention.

MATERIALS AND METHODS

A sub-analysis was performed using data from the LIBERTY trial (ClinicalTrials.gov identifier NCT01855412), a prospective, observational, core-laboratory adjudicated, multicenter study of endovascular intervention in 1204 patients. Patients with CLTI (Rutherford Classification 4-6) who underwent BTK intervention were included in this sub-analysis. Participants were then stratified into 2 treatment groups according to whether at least one lesion intervened on was BTA (n=66) or not (n=273). The decision on whether and where to intervene was made during the procedure. The main outcome measures included major amputation, target vessel revascularization (TVR), major adverse events (MAE), survival, amputation-free survival, major adverse limb events or peri-operative death (MALE-POD), and all-cause death. Other outcome measures included procedural success, procedural complications, and wound healing rate.

RESULTS

There were no differences in procedural success or severe angiographic complications between the 2 groups. At 1-year post-procedure, patients in the BTK group had a higher rate of freedom from major amputation (95.0% vs. 86.9%, respectively; HR: 2.87, 95% CI: 1.17-7.03), a higher rate of freedom from TVR (80.1% vs. 66.9%, respectively; HR: 1.94, 95% CI: 1.14-3.32), a higher rate of freedom from MALE-POD (94.6% vs. 86.9%, respectively; HR: 2.65, 95% CI: 1.10-6.41), and a higher rate of freedom from MAE at both 1 (76.0% vs. 60.1%, respectively; HR: 2.00, 95% CI: 1.24-3.22) and 3 years post procedure (67.5% vs. 55.8%, respectively; HR: 1.69, 95% CI: 1.08-2.65). There was a significantly lower rate of survival in the BTK group at 3 years (74.3% vs. 91.1%, respectively; HR: 0.35, 95% CI: 0.14-0.87). After risk adjustment, there was a higher rate of all-cause death in the BTK group at 3 years (19.4% vs. 9.1%, respectively; p=0.023) post-intervention.

CONCLUSION

Patients with disease requiring intervention to BTA lesions have a potential increased amputation rate in the short term, but BTA intervention carries a potential survival benefit in the long term when compared to BTK intervention alone.

Endovascular reconstruction of popliteal and infrapopliteal arteries for limb salvage and wound healing in patients with critical limb ischemia - A retrospective analysis

Background

Advancement in endovascular techniques has led to rapid growth in endovascular revascularization, and it has emerged as a treatment for critical limb ischemia (CLI). Clinical effectiveness of revascularization has been frequently judged by vessel patency and limb salvage, but there is paucity of reports on outcomes of the wound. We present a retrospective analysis of immediate angiographic and 3-month clinical outcome of patients who underwent endovascular reconstruction of popliteal and infrapopliteal arteries for CLI.

Methods

All patients who underwent endovascular reconstruction of popliteal and/or infrapopliteal arteries for CLI and >70% stenosis on digital subtraction angiography between March 2010 and November 2014 and had a clinical follow-up of at least 3 months were selected for analysis.

Results

34 patients underwent endovascular reconstruction. 9 patients (26%) underwent only POBA and remaining 25 (74%) underwent additional stenting. 13 patients (38%) had multiple segmental revascularization. 24 patients (71%) had successful vessel recanalization. Linear flow to foot in at least one artery could be achieved in 20 patients (59%) post revascularization. Successful wound healing occurred in 11 (35%) patients with an additional 7 (21%) patients showing clinical improvement in their wounds. Limb salvage was achieved in 33 patients (97%) at 3-month follow-up.

Conclusion

Endovascular revascularization of popliteal and infrapopliteal arteries is a feasible, safe, and effective procedure for the treatment of CLI. Normal inflow and outflow with at least one of the three infrapopliteal vessels being patent is essential for adequate healing of chronic ulcers and prevention of major amputation.

Feasibility of endovascular recanalization of occluded infrapopliteal drug-eluting stents

PURPOSE

To investigate the safety and feasibility of percutaneous endovascular recanalization of late total occlusions of infrapopliteal drug-eluting stents (DES).

METHODS

A retrospective study investigated all 408 infrapopliteal stent procedures performed in 367 patients between January 2007 and October 2013 to identify those who underwent percutaneous reintervention for symptomatic infrapopliteal balloon-expandable DES occlusion. The search identified 49 patients with at least one infrapopliteal DES occlusion in 61 (14.9%) of 408 limbs. Seven (14.3%) patients were excluded from the analysis owing to asymptomatic status (n=6) and acute thrombotic occlusion (n=1), leaving 42 patients who underwent endovascular revascularization of occluded stents in 54 limbs. The study's primary outcomes were technical success and complication rates of endovascular recanalization, while secondary outcomes included limb salvage and the identification of factors influencing primary results.

RESULTS

Technical success was 90.7% (49/54 procedures). Technical failure was seen only in cases of stent collapse and overlapping native popliteal artery-infrapopliteal stent occlusion. According to Kaplan-Meier analysis, survival was 89.6%, 81.1%, and 73.5% at 1, 2, and 3 years, respectively, while limb salvage rates were 86.1%, 79.3%, and 72.7% at the same time points. There was 1 (1.8%) case of distal embolization. No factors influencing outcomes could be identified.

CONCLUSION

Percutaneous recanalization of infrapopliteal stent total occlusions is safe and feasible. Technical failure was noted in cases of stent deformation occurring at the pedal artery and in overlapping native popliteal artery-infrapopliteal stent occlusion.

Endovascular recanalization of infrapopliteal occlusions in patients with critical limb ischemia

BACKGROUND

Endovascular therapies are increasingly used for treatment of critical limb ischemia (CLI). Infrapopliteal (IP) occlusions are common in CLI, and successful limb salvage may require restoration of arterial flow in the distribution of a chronically occluded vessel. We sought to describe the procedural characteristics and outcomes of patients with IP occlusions who underwent endovascular intervention for treatment of CLI.

METHODS

All patients with IP interventions for treatment of CLI from 2006 to 2012 were included. Angiographic and procedural data were compared between patients who underwent intervention for IP occlusions vs IP stenosis. Restenosis was determined by Doppler ultrasound imaging. Limb salvage was the primary end point of the study. Additional end points included primary patency, primary assisted patency, secondary patency, occlusion crossing success, procedural success, and amputation-free survival.

RESULTS

A total of 187 patients with CLI underwent interventions for 356 IP lesions, and 77 patients (41%) had interventions for an IP occlusion. Patients with an intervention for IP occlusion were more likely to have zero to one vessel runoff (83% vs 56%; P < .001) compared with interventions for stenosis. Compared with IP stenoses, IP occlusions were longer (118 ± 86 vs 73 ± 67 mm; P < .001) and had a smaller vessel diameter (2.5 ± 0.8 vs 2.7 ± 0.5 mm; P = .02). Wire crossing was achieved in 83% of IP occlusions, and the overall procedural success for IP occlusions was 79%. The overall 1-year limb salvage rate was 84%. Limb salvage was highest in the stenosis group, slightly lower in the successful occlusion group, and lowest in the failed occlusion group (92% vs 75% vs 58%, respectively; P = .02). Unsuccessfully treated IP occlusions were associated with a significantly higher likelihood of major amputation (hazard ratio, 5.79; 95% confidence interval, 1.89-17.7) and major amputation or death (hazard ratio, 2.69; 95% confidence interval, 1.09-6.63).

CONCLUSIONS

Successful endovascular recanalization of IP occlusions can be achieved with guidewire and support catheter techniques in most patients. In patients selected for an endovascular-first approach for IP occlusions in CLI, this strategy can be successfully implemented with favorable rates of limb salvage.

Evaluation of below-the-knee drug-eluting stents with frequency-domain optical coherence tomography: neointimal hyperplasia and neoatherosclerosis

PURPOSE

To report the use of intravascular frequency-domain optical coherence tomography (FD-OCT) to detect and characterize in-stent neointimal tissue following infrapopliteal drug-eluting stent (DES) placement in patients suffering from critical limb ischemia.

METHODS

This prospective study included 12 patients (7 men; mean age 72.8±7.2 years) who had previously received 21 infrapopliteal sirolimus- or everolimus-eluting stents. The patients returned for regular angiographic follow-up or presented with clinical relapse of symptoms over a mean follow-up of 13.5±7.3 months (range 6-33), at which time FD-OCT imaging was performed. Study endpoints were technical imaging success, defined as successful FD-OCT acquisition and visualization of the arterial lumen and complete vessel wall, and the detection and characterization of in-stent neointimal hyperplasia according to widely accepted OCT criteria.

RESULTS

OCT imaging was successfully completed in 19 of the 21 stents. Binary in-stent restenosis (ISR>50%) was detected in 10/19 stents. Percent restenosis was higher after longer follow-up (60.6%±19.8% ≥1 year vs. 35.3%±20.6% <1 year, p=0.03) and in symptomatic vs. asymptomatic patients (61.5%±20.4% vs. 37.2%±19.3%, p=0.04). Neoatherosclerosis findings included lipid-laden neointima (16/19), neointimal neovascularization (13/19), neointimal calcifications (6/19), and thrombus (5/19); no cases of thin-cap fibroatheroma were identified. Neointimal calcifications were more frequent after ≥12 months of follow-up compared to <12 months (46.6% vs. 0%, p=0.02).

CONCLUSION

FD-OCT of the infrapopliteal arteries following DES placement is safe and feasible and may demonstrate features of developing neointimal neoatherosclerosis. The latter might play a key role as a mechanism of below-the-knee ISR and warrants further investigation.

Infrapopliteal application of sirolimus-eluting versus bare metal stents for critical limb ischemia: analysis of long-term angiographic and clinical outcome

PURPOSE

To present the 3-year angiographic and clinical results of a prospective registry investigating the performance of sirolimus-eluting stents (SESs) versus bare metal stents (BMSs) for critical limb ischemia (CLI) treatment.

MATERIALS AND METHODS

A single-center double-arm prospective registry included patients with CLI who underwent infrapopliteal revascularization with angioplasty and "bailout" use of an SES or BMS. Clinical and angiographic follow-up was scheduled at regular time intervals. Primary clinical and angiographic endpoints included mortality, limb salvage, primary patency, binary angiographic restenosis (ie, >50%), and clinically driven repeat intervention-free survival. Results were stratified according to stent type, and cumulative proportion outcomes were determined by Kaplan-Meier plots. Multivariable Cox proportional-hazards regression analysis was applied to adjust for confounding factors of heterogeneity.

RESULTS

In total, 103 patients were included in the analysis; 41 (75.6% with diabetes) were treated with a BMS (47 limbs; 77 lesions) and 62 (87.1% with diabetes) with an SES (75 limbs; 153 lesions). At 3 years, SES-treated lesions were associated with significantly better primary patency (hazard ratio [HR], 4.81; 95% CI, 2.91-7.94; P < .001), reduced binary restenosis (HR, 0.38; 95% CI, 0.25-0.58; P < .001), and better repeat intervention-free survival (HR, 2.56; 95% CI, 1.30-5.00; P = .006) versus BMS-treated ones. No significant differences were identified between SESs and BMSs with regard to overall 3-year patient mortality (29.3% vs 32.0%; P = .205) and limb salvage (80.3% vs 82.0%; P = .507).

CONCLUSIONS

Infrapopliteal application of SESs for CLI significantly improves angiographic long-term patency and reduces infrapopliteal vascular restenosis versus BMSs, thereby lessening the rate of clinically driven repeat interventions.