PURPOSE

To investigate the angiographic dissection patterns after balloon angioplasty for superficial femoral artery (SFA) lesions, the clinical outcome associated with each dissection pattern, and the predictive factors for severe dissection.

METHODS

A retrospective, multicenter analysis examined 621 patients (mean age 72.8±9.5 years; 414 men) with 748 symptomatic de novo SFA lesions treated with endovascular therapy. Vessel dissection after the initial balloon angioplasty procedure was graded into 7 types according to a modified version of the coronary artery classification types A to F. Severe vessel dissection patterns were defined as type C or higher. Nitinol stent implantation was performed in 555 (74.2%) lesions for residual stenosis >30% or flow-limiting dissection; 193 lesions (25.8%) were treated with balloon angioplasty only. To determine the clinical outcomes associated with each dissection pattern and identify predictive factors for severe dissection, 2-year follow-up data for the 193 lesions treated with balloon angioplasty only were analyzed for primary patency and clinically driven target lesion revascularization (TLR).

RESULTS

No dissection was found in 16% (120/748) of lesions, and types A and B dissections were seen in 19% (142/748) and 23% (172/748), respectively. Dissection grades above type C were observed in 42% of cases, most frequently type D (180/748, 24%) and less often type C (37/748, 5%), type E (67/748, 9%), and type F (30/748, 4%). The bailout stent implantation rate increased according to dissection severity. At up to 2 years, the severe dissection group (types C-F) showed a significantly lower patency rate (p<0.001) and higher clinically driven TLR (p<0.001) compared to the nonsevere group (no dissection and types A and B dissections). Severe dissection was a significant risk factor for restenosis, which rose progressively from types C to F. Multivariate analysis identified a small reference vessel diameter <5 mm (p=0.001), lesion length >15 cm (p=0.001), and chronic total occlusion (p<0.001) as independent predictors of severe dissection. In subgroup analysis, vessels with a small reference diameter and TASC II C and D lesions had a higher prevalence of severe dissection.

CONCLUSION

Severe dissection was found in 42% of cases after PTA. A small vessel diameter and/or TASC II C/D lesions were related to a high incidence of dissection. Severe dissection during procedures employing balloon angioplasty only could affect long-term patency.