Selective Stenting in Subintimal Angioplasty: Analysis of Primary Stent Outcomes

Background: Our current practice utilizes selective stenting after femoropopliteal subintimal angioplasty (SIA). The outcome and predictors of success using this selective approach are unknown. To better define these factors which affect patency and clinical outcome, we reviewed our cumulative experience in this subset of SIA patients receiving primary stents.
Methods: A retrospective review of patients who underwent femoropopliteal SIA at our institution was performed. Patient history, demographics, procedural details, and follow-up information were collected and analyzed. Patency and limb salvage rates were determined by Kaplan-Meier analysis.
Results: From December, 2002, through July, 2006, 390 SIA procedures were performed; 298 without stents (NST) and 92 with stents (ST). The mean age of patients treated was 69±13years. Demographics between the patients receiving stents and those without stents were similar, except for a higher presence of hyperlipidemia in the stent group (50% vs. 35%; p=0.011). Indications for intervention were critical limb ischemia (CLI) [51% Stent vs. 58% No stent; p=NS] and disabling claudication (DC) [48% Stent vs. 42% No stent; p=NS]. The SIA was located in the superficial femoral (96%), popliteal (51%), and infrapopliteal (14%); half of these covered multiple segments. Mean follow-up was 8.3 months (range, 0-38 months). Primary patency and secondary patency for ST versus NST at 1 year was 50% vs. 45% (p=NS)&71% vs. 78% (p=NS), respectively. 30-day periprocedural mortality was 0.8%. In patients with CLI, the limb salvage rate at 1 year for ST vs. NST was 78% vs 89% (p=NS). Freedom from bypass at 1 year for ST vs. NST was 83% vs 90% (p=NS). Maintenance of claudication relief for ST vs. NST was 84% vs. 88% (p=NS).
The indications for stent use were suboptimal angioplasty (60%), dissection flap (35%), and residual calcified stenosis (11%). Stents were placed in the superficial femoral (83%), popliteal (26%), and infrapopliteal (3%) arteries. The mean number of stents deployed was 1.52±0.8 (range: 1-5). The mean stent diameter was 7.0mm (range: 5mm-10mm). The average stent length used was 99mm±73mm (range: 15mm-340mm). Univariate analysis within the ST group revealed significantly improved patency for stents utilized in patients with claudication (61%) versus critical limb ischemia (39%) (p=0.018). Also, patients who had a previous lower extremity bypass surgery had significantly decreased one-year patency (13%) versus those without previous bypass (58%) (p=0.005). Further analysis did not show a difference for other procedural or demographic variables.
Conclusions: Selective stents placed for suboptimal results after subintimal angioplasty produce similar patency rates to primary subintimal angioplasty without stents. Worse outcomes should be expected in patients with prior lower extremity bypass surgery or critical limb ischemia. It appears that specific, stent variables (location, number, length, diameter, and overlap) do not affect patency. Finally, selective stent placement for subintimal angioplasty provides excellent limb salvage.