Distal Embolic Protection for Infrainguinal Interventions: How to and When?

Retrograde Balloon-Assisted Approach to Prevent Distal Embolization During Complex Recanalization Procedures

PURPOSE

The purpose of the study is to describe a bailout technical strategy to prevent below-the-knee (BTK) distal embolization during procedures with increased inherent risk using universally-available "off-the-shelf" devices.

TECHNIQUE

A conventional retrograde access is obtained of the BTK target vessel where embolization protection is sought. Before starting any potential proximal maneuver with an associated significant risk of distal embolization (eg, atherectomy and mechanical thrombectomy), a low-profile balloon is inserted and inflated through the distal retrograde access, so that any debris resulting from the recanalization procedure is blocked by the stagnant column of blood generated by the inflated balloon. Once the revascularization procedure has been completed, a 4F curved catheter is antegradely advanced down to the distally-inflated balloon, and in case of distal embolization the debris is aspirated in a standard fashion way.

CONCLUSION

A retrograde balloon-assisted "off-the-shelf" embolic protection approach may be considered for BTK revascularization procedures where there is an inherent increased risk of distal trash, especially in the presence of distal single-vessel runoff.

CLINICAL IMPACT

Distal embolization following endovascular procedures can have devastating consequences and there is a general recommendation for selective use of EPDs in high-risk-scenarios. The increased cost and low availability of the current EPD devices for BTK/BTA arteries have prohibited their widespread use. The retrograde balloon-assisted "off-the-shelf" EPD prevents distal embolization during procedures with increased risk of distal trash using inexpensive, nonspecific equipment available in any basic endovascular suite.

Percutaneous Aspiration Thrombectomy for Arterial Thromboembolism during Infrainguinal Endovascular Recanalization

Objectives

To evaluate the efficacy of percutaneous aspiration thrombectomy (PAT) for infrainguinal arterial thromboembolism in patients undergoing endovascular recanalization (EVR) and to investigate the predictors for thromboembolic complications.

Materials and Methods

In total, 23 patients (23 limbs) who underwent PAT for thromboembolism (PAT group, PG) during EVR and 237 patients (302 limbs) who underwent successful EVR without thromboembolic complications (control group, CG) were enrolled. Immediate post-operation and follow-up outcomes were compared between the two groups. Multivariate analysis was performed to identify the predictors of thromboembolic complications. Technical success of PAT was defined as achievement of <30% residual stenosis and restoration of mTIMI grade 3.

Results

The technical success rate was 95.7% in PG. After intervention, the ankle–brachial index (ABI), restoration of blood flow and improvement in dorsal/plantar arterial pulse score showed no significant differences between PG and CG. During follow-up in PG, a sustained ABI improvement was observed in 63.6% (70.9% in CG), an improvement in walking distance in 68.8% (79.9% in CG,), ulcer healing in 75.0% (71.7% in CG) and restenosis/occlusion in 31.8% (25.2% in CG). The limb salvage rate was 100% in PG (96.0% in CG), and pain relief was observed in 66.7% patients with critical limb ischaemia (81.6% in CG). Superficial femoral artery involvement [0.233; 95% confidence interval (CI), 0.108–0.461; P < 0.001], de-novo lesion occlusion (683.8; 95% CI, 36.5–12804.6; P < 0.001) and intraluminal angioplasty (118.4; 95% CI, 8.0–1758.0; P = 0.001) was associated with high incidence of thromboembolism.

Conclusion

PAT is a safe and effective treatment for thromboembolism during infrainguinal arterial EVR. SFA involvement, de-novo lesion occlusion and intraluminal angioplasty may be predictors of thromboembolic complications.

Incidence, risk factors, treatment and prognosis of popliteal artery embolization in the superficial femoral artery interventions

Objective

Percutaneous transluminal angioplasty and stenting (PTA + stent) has gained acceptance as a primary treatment modality for the superficial femoral artery (SFA) diseases. Popliteal artery embolization (PAE) is a severe complication in SFA interventions. The purpose of this study was to evaluate the incidence, risk factors, treatment and prognosis of PAE in primary SFA PTA + stent.

Methods

Chronic SFA arteriosclerosis cases that underwent primary PTA + stent were reviewed from a retrospectively maintained database. Runoff vessels were evaluated in all cases before and after the interventions for PAE detection. The primary patency, secondary patency and limb salvage rates were calculated using Kaplan-Meier analysis and compared using log-rank analysis. Cox multivariate regression was performed to evaluate predictors of patency and limb salvage rates.

Results

There were 436 lesions treated in 388 patients with 10 PAE events (2.3%) in total. PAE rate was significantly higher in Transatlantic Inter-Society Consensus (TASC) C/D group compared with TASC A/B group (OR = 8.91, P = .002), in chronic total occlusion (CTO) lesions compared with stenotic lesions (P<.0001), and in group with history of cerebral ischemic stroke (OR = 6.11, P = .007). PAE rates were not significantly affected by age, sex, smoking, hypertension, diabetes, hyperlipidemia and runoff status. The binary logistic regression showed that only the TASC C/D was an independent predictor of PAE (P = .031). The 12-month and 24-month primary patency, secondary patency and limb salvage rates in PAE group showed no significant differences comparing with non-PAE group.

Conclusions

PAE is a rare event in primary SFA PTA + stent. TASC C/D lesion, CTO and cerebral ischemic stroke history are risk factors for PAE. PAE is typically reversible by comprehensive techniques. If the popliteal flow is restored in time, PAE has no significant effect on long-term patency and limb salvage rates.

Do thrombotic events during endovascular interventions lead to poorer outcomes in patients with severe limb ischemia?

INTRODUCTION

Intra-procedural acute thrombosis (IPAT) is a complication of endovascular procedures. We aim to identify risk factors for IPAT and compare the outcomes of patients with or without IPAT.

METHODS

Paired T test and χ (2) test were used to identify risk factors and short-term outcomes. Kaplan-Meier survival analysis was used for mid-term outcomes.

RESULTS

A total of 228 procedures were performed with 21 IPAT events (9.21%). The odds ratio of Indian patients developing IPAT was 2.8x (95% CI 1.1-7.6). Patients with in-stent occlusion or prior IPAT were 5.6x (95% CI 1.3-24.2) and 5.6x (95% CI 1.3-24.4) more likely to develop an IPAT event. Patients without IPAT had significantly more improvement in mean runoff score (-1.15 ± 1.31, p < 0.01). The odds of patients with IPAT requiring subsequent endovascular intervention and arterial bypass surgery were 4.2x (95% CI 1.6-10.7) and 7.1x (95% CI 1.9-27.0). There was no significant Kaplan-Meier estimated overall survival or amputation-free survival difference between patients with or without IPAT event.

CONCLUSION

Indian ethnicity, in-stent occlusion and previous IPAT were associated with higher risk of IPAT. Even after successful endovascular salvage, patients with IPATs were more likely to require secondary revascularization procedure. Patients with IPATs had no decrease in overall survival or amputation-free survival.

A role for embolic protection in the management of acute limb ischemia

Distal embolization is a complication during lower-extremity revascularization procedures that may occur when intervening on acute or subacute lesions. Several studies have demonstrated the safety and feasibility of using embolic protection devices (EPD) and some interventionalists have adapted this technology for use in infrainguinal revascularization procedures. At present, there are no randomized trials to indicate the benefit, safety, and cost-effectiveness of EPD for this application and its use in the United States is considered off-label. However, based on our experience and a review of the published literature, we consider the use of EPD in acute lower-extremity ischemia a reasonable strategy.