Safety and 1-year revascularization outcome of SilverHawk atherectomy in treating in-stent restenosis of femoropopliteal arteries: a retrospective review from a single center.

Background: Treatment of in-stent restenosis of the femoropopliteal arteries with balloon angioplasty carries a high rate of recurrence and requires frequent repeat stenting. In the "Instructions for Use," SilverHawk atherectomy (SA) is contraindicated for in-stent restenosis at a peripheral site. SA, however, has a theoretical advantage of reducing the volume of restenotic tissue and potentially delaying the need for frequent repeat revascularization and additional stenting. We present a retrospective analysis from our center on the safety and outcomes of SA in the treatment of in-stent restenosis of the femoropopliteal arteries.

Methods: Demographic, clinical, angiographic, and procedural data were collected on all patients who underwent SA for in-stent restenosis from February 2005 to April 2010 at a single medical center. Major adverse events and 1-year target lesion revascularization (TLR) and target vessel revascularization (TVR) were obtained by review of medical records and phone calls. Descriptive analysis was performed on all variables. Kaplan-Meier survival curves for TVR were plotted.

Results: A total of 41 consecutive patients (mean age 70.9±9.2 years, 56% males) were included and followed for a mean of 331.63 days. The following variables were noted: mean ankle brachial index (ABI) of treated leg 0.66±0.2; chronic renal failure (creatinine >2.0 at baseline) 14.6%; diabetes 61%; history of smoking 85.4%; number of vessel runoffs of treated limb 1.9±0.9; hypertension 90.2%; lesion length 126.2±79.3mm; lesion severity 90.7±8.2%; vessel diameter 5.8±0.7 mm. All patients received bivalirudin during the procedure and were on aspirin. Ninety-five percent of patients were placed on clopidogrel. Adjunctive balloon angioplasty was performed in 97.6% at a mean pressure of 11.9±3.3atm. Embolic filter protection (EFP) was used in 56.1% of patients. Bailout stenting was 24.4%. Acute procedural success (<30% angiographic residual narrowing) occurred in 100% of patients. Compared to baseline, ABI at 1 month significantly improved to 0.91±0.19 (P<0.05) but was not statistically different at 1 year (0.61±0.28). Debris was noted in 81.9% of filters used; 36.4% were macrodebris. The following adverse events were reported: distal embolization (DE) requiring treatment 7.3%; stent thrombosis 4.9%; planned minor amputation in the nonindex limb 2.4%. No device-related complications occurred. There was no death or amputation. TLR and TVR occurred in 31.7% and 34.1%, respectively.

Conclusion: SA has favorable acute results in treating in-stent restenosis of the femoropopliteal arteries. At 1 year, TLR and TVR remain high but compare favorably to published data. DE also occurs significantly with SA and EFP appears to be effective in capturing the debris.