Assessment of primary patency for femoropopliteal graft entrapment within the sartorius muscle.

ABSTRACT

PURPOSE: Blind tunneling of subfascial femoropopliteal bypass grafts may result in inadvertent graft passage through the sartorius. The purpose of this study was to determine whether intramuscular passage of femoropopliteal bypass grafts affects primary patency. METHODS: Patients undergoing femoropopliteal bypass at a Veterans Administration hospital and associated university medical center over a recent 13-year period who also had postoperative cross-sectional imaging adequate to determine graft location were examined. Five-year primary patency of grafts circumferentially enveloped by the muscle was compared with that of both extramuscular subfascial grafts and subcutaneous grafts. RESULTS: 370 femoropopliteal grafts were identified, among which 258 (70%) were subfascial. Vein grafts comprised 51% of the subfascial grafts, and 53% were inserted above the knee. Available postoperative imaging in 110 subfascial grafts demonstrated 74 (67%) to lie completely within the muscle at some point. Among imaged subfascial grafts, primary patency at five years for intramuscular grafts was not significantly worse than extramuscular grafts (P = 0.31). This remained true whether grafts were vein (P = 0.39) or prosthetic (P = 0.31) and whether grafts inserted to the above-knee (P = 0.43) or below-knee (P = 0.21) popliteal artery. Multivariable Cox regression revealed a significant relationship between use of vein grafts (P = 0.013), active smoking (P = 0.01), and hypertension (P = 0.041) and primary patency, but not intramuscular graft location (P = 0.31). CONCLUSION: This study failed to demonstrate significantly inferior primary patency among subfascial femoropopliteal grafts tunneled intramuscularly. Larger studies may be required to adequately detect any differences in patency by muscular entrapment, especially among subgroups.