Analysis of Interwoven Nitinol Stenting for the Treatment of Critical Limb Ischemia: Outcomes From an Average 3-Year Follow-up Period

The BioMimics 3D Helical Centreline Nitinol Stent in Chronic Limb Threatening Ischaemia and Complex Lesions: Three Year Outcomes of the MIMICS-3D Registry

OBJECTIVE

There is a need for improved outcomes in the endovascular treatment of patients suffering from chronic limb threatening ischaemia (CLTI), highly calcified lesions, and chronic total occlusions (CTOs). The helical centreline self expanding BioMimics 3D stent might be particularly useful in these high risk subsets, combining flexibility and fracture resistance with radial strength. Herein, the performance of the BioMimics 3D stent was assessed in these high risk subsets.

METHODS

MIMICS-3D is a prospective, multicentre, European real world registry. This was a post hoc analysis, comparing patients with CLTI vs. intermittent claudication (IC), lesions with bilateral calcification vs. those without (peripheral arterial calcium scoring system [PACSS] 3,4 vs. PACSS 0 - 2), and CTO vs. no CTO. Propensity score matching was performed to reduce the impact of baseline variables. The 36 month endpoints were clinically driven target lesion revascularisation (CD-TLR), death, major target limb amputation, and stent patency.

RESULTS

A total of 507 patients were enrolled. At 36 months, patients with CLTI had lower freedom from major amputation than patients with IC (92.6% vs. 100%, p < .001). In terms of primary patency, patients with CTO had lower patency rates than those without (63.9% vs. 77.8%, p = .003), but the difference reduced after propensity score matching (70.5% vs. 76.8%, p = .43). Primary patency was not impaired for patients with PACSS 3,4 or patients with CLTI. Freedom from CD-TLR was not significantly different among the groups and was 73.8% for CLTI vs. 78.9% for IC (p = .15), 77.6% for PACSS 3,4 vs. 78.7% for PACSS 0 - 2 (p = .55), and 75.6% for CTO vs. 81.0% for no CTO (p = .11).

CONCLUSIONS

The outcome of the MIMICS-3D registry suggests that the BioMimics 3D stent is effective in the endovascular treatment of complex femoropopliteal lesions and in CLTI. Future randomised controlled trials should confirm its non-inferiority or superiority compared with existing alternatives.

Outcomes for Patients With Chronic Limb-Threatening Ischemia After Direct and Indirect Endovascular and Surgical Revascularization: A Meta-Analysis and Systematic Review

PURPOSE

The purpose of this review and meta-analysis is to determine the clinical outcome differences between patients with chronic limb-threatening ischemia who underwent direct versus indirect angiosome revascularization using either the surgical or endovascular approach.

MATERIALS AND METHODS

The data sources used for article selection included PubMed, Embase/Medline, Cochrane reviews, and Web of Science (All studies were in English and included up to September 2023). All articles included were comparative in design, including retrospective, prospective, and randomized controlled trials that compared the clinical outcomes between direct and indirect angiosome-guided revascularization in chronic limb-threatening ischemia. A random-effects model was used to determine the measure of association between direct revascularization and amputation-free survival, wound healing, and overall survival. Publication bias was assessed with both Begg's and Egger's test, and heterogeneity was calculated using an I2.

RESULTS

Data from 9 articles were analyzed and reported in this review. Direct revascularization was associated with improved amputation-free survival (odds ratio [OR]=2.632, confidence interval [CI]: 1.625, 4.265), binary wound healing (OR=2.262, CI: 1.518, 3.372), and overall survival (OR=1.757, CI: 1.176, 2.625). Time until wound healed was not associated with either direct or indirect revascularization (Standard Mean Difference [SMD]=-2.15, p=0.11). There was a low risk of bias across all studies according to the RoB 2.0 tool.

CONCLUSION

Direct revascularization is associated with improved amputation-free survival, overall survival, and wound healing in chronic limb-threatening ischemic patients compared to the indirect approach.

CLINICAL IMPACT

Preservation of the lower extremity is critical for preventing mortality and maintaining independence. The benefit of angiosome-guided revascularization for chronic limb-threatening ischemia remains controversial. The authors of this article aim to review the current literature and compare direct and indirect angiosome-guided intervention for preserving the lower extremity. Current findings suggest direct angiosome-guided intervention reduces amputation rates and improves survival; however, many trials neglect to address the multifactorial approach needed in wound care management.

Biomimetic Stents for Infrainguinal Peripheral Arterial Disease: Systematic Review and Meta-Analysis

OBJECTIVE

Biomimetic stents are peripheral infrainguinal self expanding stents that mimic the anatomy of the vasculature and artery movement. They are indicated for use in infrainguinal arteries. This research aimed to synthesise all current evidence on the use of biomimetic stents as adjuncts for endovascular treatment of infrainguinal peripheral arterial disease (PAD), helping to guide clinical decision making.

DATA SOURCES

MEDLINE, Embase, CINAHL and Cochrane databases.

REVIEW METHODS

Random effects meta-analysis following PRISMA guidelines (PROSPERO registration CRD42022385256). Study quality was assessed using the Joanna Briggs Institute critical appraisal tools checklist, and certainty assessment through the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Endpoints included primary patency, target lesion revascularisation, stent fracture, secondary patency, and Death at one year.

RESULTS

In total, 37 studies were included in the meta-analysis (33 cohort studies, two case series, and two randomised controlled trials [RCTs]), representing 4 480 participants. Of these, 34 studies included data on the Supera (81.5% of participants) and three studies reported data on the BioMimics 3D (18.5% of participants) stents. The pooled primary patency rate of 33 studies at one year follow up was 81.4% (95% confidence interval [CI] 78.7 - 83.9%), and the pooled target lesion revascularisation rate of 18 studies at one year was 12.2% (95% CI 9.6 - 15.0%). The certainty of evidence outcome rating as qualified by GRADE was very low for both. Only one study reported a positive stent fracture rate at one year follow up of 0.4% with a certainty of evidence outcome of low.

CONCLUSION

Using biomimetic stents for infrainguinal PAD may be associated with acceptable one year primary patency and target lesion revascularisation rates, with a near negligible one year stent fracture rate. Their use should be considered in those presenting with infrainguinal PAD undergoing endovascular revascularisation. A RCT is necessary to determine their clinical and cost effectiveness.