Fate of popliteal artery aneurysms after exclusion and bypass.

Background: Treatment of popliteal aneurysm (PA) includes exclusion and bypass graft. In excluded sac, persistent flow through collateral arteries (endoleak) could result in aneurysm growth.

Methods: We retrospectively reviewed PA treated by exclusion and bypass, using duplex ultrasound or computed tomography (CT) scans to demonstrate the presence of residual flow and sac growth.

Results: Between 1997 and 2007, we treated 53 PAs in 46 patients by ligation and bypass grafting using polytetrafuoroethylene (PTFE) or saphenous vein. The mean PA diameter preoperatively was 33.4 mm (range, 20-70 mm). At a mean follow-up period of 35 months, 75% (n = 40) PA showed a decrease in mean transverse diameter, from 33.4 to 27.3 mm (p < 0.001). In 17% patients (n = 9), aneurysm sac size remained unchanged, whereas in 8% (n = 4) it increased (mean, 4.5 mm). In six cases (11%), persistent sac flow was revealed by Duplex or TC scan. One patient with a large aneurysm that increased by 50% underwent endoaneurysmorrhaphy through a posterior approach because of symptoms related to local compression. No rupture occurred in follow-up period. The cumulative Kaplan-Meier patency rate at 12, 36, and 60 months were 86%, 76%, and 69%, respectively. Limb salvage rate at 5 years was 92%. Cumulative patency rate at 60 months in the group with popliteal artery unchanged or increased resulted significantly lower than the group with aneurismal sac decreased (30% vs. 84%; p < 0.001). Multivariate analysis did not show correlation between risk factors or preoperative aneurysm diameter, and increased or decreased sac size.

Conclusions: In our results, aneurysm sac growth exists but is low, and a persistent sac flow was not correlated to increased sac size. In view of these results, we believe that medial approach for popliteal artery reconstruction can be used because the aneurysm increase is low and the risk of rupture is not important. No decrease of sac size was otherwise significantly correlated to graft patency.