Long-term outcomes following 282 consecutive cases of infrapopliteal PTA and association of risk factors with primary patency and limb salvage

Temsirolimus Adventitial Delivery to Improve ANGiographic Outcomes Below the Knee

BACKGROUND

Current endovascular treatments of below the knee (BTK) popliteal or tibial/peroneal arteries including investigational drug-coated balloons have limited long-term efficacy.

OBJECTIVES

This Phase 2 trial assessed the feasibility of adventitial deposition of temsirolimus to reduce neointimal hyperplasia and clinically relevant target lesion failure (CR-TLF) 6 months after BTK arterial revascularization.

METHODS

This prospective, multicenter, double-blinded, comparative, dose-escalation trial enrolled 61 patients with Rutherford 3 to 5 symptoms undergoing endovascular revascularization of ≥1 angiographically significant BTK lesions. Perivascular infusion after completion of arterial revascularization was randomized into control (saline) vs low-dose (0.1 mg/mL) temsirolimus groups for the first 30 patients. In the second part of the trial, patients were randomized to control versus high-dose (0.4 mg/mL) temsirolimus groups. Primary and secondary efficacy endpoints were target lesion (TL) transverse-view vessel area loss percentage (TVAL%) and CR-TLF at 6 months, respectively. CR-TLF was defined as a composite of ischemia-driven major amputation of the target limb, clinically driven target lesion revascularization (CD-TLR), and clinically relevant TL occlusion. The primary safety endpoint was freedom from major adverse limb events or perioperative death (MALE+POD) at 30 days.

RESULTS

There was no discernable difference in effect between temsirolimus doses; therefore, the low- and high-dose cohorts were pooled for the analyses. The principal analysis on the per protocol (PP) group of 53 patients revealed superior primary efficacy of the treatment arm, with reduction in TVAL% of 13.9% absolute (37.3% relative) and the rate of CR-TLF reduced by 27.1% absolute (51.3% relative), at 6 months. Subgroup analysis of all Trans-Atlantic Inter-Society Consensus (TASC) B to D lesions (N=36) revealed TVAL% reduction of 22.3% absolute (48.3% relative) and the rate of CR-TLF reduced by 39.2% absolute (56.6% relative). Freedom from 30-day MALE+POD was 100% in all groups.

CONCLUSIONS

This hypothesis-generating trial suggests that adventitial infusion of temsirolimus in BTK arteries improves TVAL% and CR-TLF with no adverse safety signals through 6 months, supporting the move to a Phase 3 trial.

CLINICAL IMPACT

There remain gaps in the endovascular treatment of patients with atherosclerotic lesions of below-the-knee (BTK) arteries. The TANGO trial evaluated the use of sub-adventitial temsirolimus with the Bullfrog micro-infusion device during BTK interventions. The therapy was safe and effective. Compared with controls, vessel lumen area patency was improved, and target lesion failure was less frequent. The effects were most appreciable in subjects with higher baseline TASC lesions (B, C, or D). Sub-adventitial temsirolimus offers the potential to improve the results of BTK interventions in this challenging patient population.

Outcomes of infrapopliteal angioplasty for limb salvage based on the updated TASC II classification

PURPOSE

We aimed to evaluate limb salvage, defined as freedom from major amputation, and to identify predictors of major amputation in patients with infrapopliteal peripheral arterial disease (PAD) based on the updated 2015 TASC II anatomic classification treated by percutaneous transluminal angioplasty (PTA).

METHODS

This was a retrospective study of infrapopliteal PTA procedures performed for PAD over a 4-year period. Patient demographics, medical comorbidities, risk factors, angiographic imaging, technical details, and clinical follow-up were analyzed to determine limb salvage rates, technical success, and all-cause mortality. Predictors of major amputation following PTA were identified.

RESULTS

A total of 112 patients were treated by infrapopliteal PTA. Most lesions consisted of TASC C (44%) and D (34%) categories, were over 10 cm in length, and were occlusive and heavily calcified (89%). Overall technical success was 75%, with limb salvage rates of 77% at 1 year and 65% at 3 years following PTA. Smoking, previous stroke or cardiovascular events, and anticoagulation use were associated with an increased risk of major amputation following PTA.

CONCLUSION

PTA of complex infrapopliteal PAD is associated with good intermediate term limb salvage rates.

Amputation-Free Survival after Crural Percutaneous Transluminal Angioplasty for Critical Limb Ischemia

Background and Aim:

To evaluate the amputation-free survival after below the knee percutaneous transluminal angioplasty in a consecutive group of patients with critical ischemia of the lower extremity.

Materials and Methods:

A total of 70 consecutive patients with critical ischemia were treated with below the knee percutaneous transluminal angioplasty at the vascular center at Rigshospitalet with the purpose of limb salvage. All patients were deemed unfit for major surgery due to anatomical limitations or severe co-morbidity, and no prior attempts of revascularization were performed. Follow-up clinical examinations were performed within 6 weeks and after 1 year. All medical records were crosschecked with the national vascular registry ensuring a valid 1-year status in 97% of the patients.

Results:

A total of 15 major amputations were performed during follow-up, with 11 amputations performed within the first year. Complications after percutaneous transluminal angioplasty were rare. Cumulative mortality after 1 and 2 years was 22% and 34%, respectively. Amputation-free survival at 1 and 2 years of follow-up was 68% and 58%, respectively. There were no association between known risk factors such as diabetes, ischemic ulcers, cardiac disease, history of smoking, major amputation, or overall amputation.

Conclusion:

Below the knee percutaneous transluminal angioplasty in patients with end-stage peripheral arterial disease and critical limb ischemia is a safe procedure in relieving critical ischemia, reducing the short-term rate of a major amputation as opposed to best medical treatment alone.

Endovascular techniques in limb salvage: infrapopliteal angioplasty

Critical limb ischemia (CLI) results from inadequate blood flow to supply and sustain the metabolic needs of resting muscle and tissue. Infragenicular atherosclerosis is the most common cause of CLI, and it is more likely to develop when multilevel or diffuse arterial disease coincides with compromised run-off to the foot. Reports of good technical and clinical outcomes have advanced the endovascular treatment options, which have gained a growing acceptance as the primary therapeutic strategy for CLI, especially in patients with significant risk factors for open surgical bypass. In fact, endovascular recanalization of below-the-knee arteries has proven to be feasible and safe, reduce the need for amputation, and improve wound healing. The distribution of various vascular territories or angiosomes in the foot has been recognized, and it appears advantageous to revascularize the artery supplying the territory directly associated with tissue loss. In addition, the targeted application and local delivery of drugs using drug-coated balloons (DCB) during angioplasty has the potential to improve patency rates compared to balloon angioplasty alone.

Systematic review and meta-analysis of balloon angioplasty versus primary stenting in the infrapopliteal disease

OBJECTIVES

We performed a systematic review and meta-analysis of comparing balloon angioplasty and primary stenting for symptomatic infrapopliteal disease to evaluate the clinical value of primary stenting in treating infrapopliteal diseases.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. PubMed (1984-present), ScienceDirect (1980-present), Embase (1990-present), and CBM (1988-present) databases were searched for relevant articles. Finally, 16 studies (published between 2001 and 2013) satisfying the inclusion criteria were identified. The outcome parameters were immediate technical success, 1-year primary patency rate, 1-year limb salvage rate, and 1-year target vessel revascularization (TVR)-free rate. Comparisons were made with balloon angioplasty and primary stenting, and based on the different types of stents, we divided the primary stent group into the bare metal stent (BMS) group and drug-eluting stent (DES) group.

RESULTS

A total of 3789 patients and 4339 limbs constituted our final study population. The technical success rate of balloon angioplasty was 92.29% (95% confidence interval [CI] 88.75%-94.78%). Only 2 study reported the technical failure rates as 4% and 5.2% in the primary stent group. The pooled estimates of 1-year primary patency and TVR-free rate were similarly low in the balloon angioplasty group and BMS group (primary patency: 57.65%, 95% CI 53.54%-61.67% vs 60.95%, 95% CI 48.31%-72.28%, P = .38; TVR-free rate: 73.41%, 95% CI 66.51%-80.08% vs 73.66%, 95% CI 63.58%-81.75%, P = .91). The pooled estimates of 1-year primary patency and TVR-free rate in DES group were 81.10% (95% CI 75.48%-85.67%) and 90.30% (95% CI 85.30%-93.73%), respectively, which were better than those of the BMS and balloon angioplasty groups (P < .001 for both). The pooled estimate of 1-year limb salvage in the balloon angioplasty, BMS, and DES groups was 88.61% (95% CI 85.01%-91.43%), 94.41% (95% CI 89.52%-97.1%), and 95.20% (95% CI 86.97%-98.33%), respectively (P < .001). The BMS and DES groups had higher limb salvage rates than the balloon angioplasty group (P < .001 for both comparisons). The rates of severe complications were low both in the balloon angioplasty and in the primary stent groups.

CONCLUSION

Primary BMS implantation had no advantage over balloon angioplasty in reducing restenosis or revascularization for infrapopliteal disease. Primary DES implantation seems to be a promising treatment for focal infrapopliteal lesions. Publication bias could not be ruled out, and the results should be treated with caution.