Cath Lab Digest

Abstract

Background. Data are limited regarding the efficacy of percutaneous mechanical thrombectomy (PMT) for the treatment of acute lower extremity (LE) ischemia. The current study was undertaken to evaluate the results following PMT for occluded LE bypass grafts, stents, and thromboembolic events involving native arteries. Methods. During a 3-year period, 43 patients underwent PMT. The patient’s outcome, including the technical success rate, additional procedures, major complications, limb salvage rate, and length of hospital stay were documented for each patient. Ultrasound follow up with clinical correlation was performed at 6 weeks and 3, 6, 12, 18, and 24 months. Results. PMT was performed for occluded synthetic bypass grafts (n = 18), vein bypass grafts (n = 6), stents (n = 4), and native arterial vessels (n = 15). The immediate technical success rate was 28% (n = 12). Twenty-one (49%) patients required adjunctive catheter-directed thrombolysis (CDT) for success. Additional endovascular procedures were performed in 30 patients (70%), with a resulting overall success rate of 77% (n = 33). The mean hospital stay was 7.2 days. A major bleeding complication occurred in one patient. In order to maintain patency during the first-year, follow-up patients required additional endovascular and or open vascular procedures. For all patients, the 6-week, 6-month, and 1-year ankle brachial index was 0.93, 0.88, and 0.95, respectively. The one-year limb salvage rate was 88%. Conclusion. PMT is a safe and effective treatment for acute lower extremity ischemia. PMT with combined CDT is associated with a high success rate and acceptable limb savage rate at one year.

Introduction

Acute lower extremity ischemia (ALI) most commonly results from thromboembolic occlusion of lower extremity arteries and bypass grafts. Open surgical thrombectomy provides rapid removal of thrombus and the restoration of blood flow, and has traditionally been the treatment of choice for ALI.1 The success of thrombolytic therapy with percutaneous catheter-directed thrombolysis (CDT) has also been demonstrated.2–4 In selected patients, CDT may provide effective treatment for ALI and reduce morbidity, compared to open surgical thrombectomy.

Percutaneous mechanical thrombectomy (PMT) has emerged as another minimally invasive option for the management of acute arterial and venous thrombus. PMT may provide stand-alone therapy for ALI or, more commonly, is used in combination with thrombolytic therapy. Although several reports have described the safety and efficacy of PMT in the peripheral circulation, the utility as a first-line therapeutic option for ALI has not been defined.5–9

The current study was undertaken to evaluate the immediate and long-term results following PMT for thromboembolic occlusion of bypass grafts, stents, and native arteries in the lower extremities.

Patients and Methods

A retrospective review identified 43 patients at our institution that underwent PMT for ALI between January 2004 and July 2007. Six vascular surgeons performed all procedures using the AngioJet Xpeedior (Possis Medical, Minneapolis, Minnesota) thrombectomy catheter. Only patients with acute occlusions (< 48 hrs) were included. Patients with contraindications to thrombolytic therapy and those with severe motorsensory deficits were excluded.

After angiographic identification of the lesion, rheolytic thrombectomy using the Power-Pulse technique was performed. The Power-Pulse technique for acute lower extremity ischemia was performed as previously described by Allie et al.9 Initial technical success was defined as > 90% thrombus removal and return of distal pulses. Patients who did not achieve technical success received CDT. Follow-up angiography was performed within 12 hours. At this time, if resolution had not been obtained, patients had either repeat rheolytic thrombectomy, repeat CDT, conversion to open thrombectomy and/or bypass, or amputation, depending on the clinical findings of the extremity. During the course of treatment, patients also received angioplasty, stent placement, and laser artherectomy, as indicated by angiographic findings.

Patient demographics and clinical characteristics are presented in Table 1. The mean patient age was 63 years ± 25. There were 26 males and 17 females. Twenty-four patients presented with occluded bypass grafts. Six patients had occluded vein bypasses: femoral-popliteal (n = 4) and femoral-tibial (n = 2). Eighteen patients presented with occluded synthetic bypass grafts: femoral-popliteal (n = 11), femoral-tibial (n = 2), aorto-femoral (n = 2), femoral-femoral (n = 1), ilio-femoral (n = 1), and ilio-popliteal (n = 1). Four patients presented with occluded infrainguinal stents. There were 15 native vessel occlusions: femoropopliteal (n = 9), tibio-peroneal (n = 4), and iliac (n = 2).

Major complications, additional procedures, and hospital stay were recorded for each patient. Ultrasound follow-up with clinical correlation was performed at 6 weeks and 3, 6, 12, 18, and 24 months. The major endpoint included limb salvage rate at 1 and 12 months.

Results

The initial technical success rate for PMT was 28% (12/43). Twenty-one patients underwent successful adjunctive CDT to yield an overall success rate of 77% (33/43). Three (7%) patients required conversion to open thrombectomy and 4 patients required surgical bypass. Twenty-eight patients (65%) had angioplasty and/or stent placement and 2 (4%) underwent laser atherectomy during the initial therapeutic intervention. Table 2 demonstrates the number of successful outcomes, as well as the number of patients requiring CDT to achieve a successful outcome based on conduit type.