Surgical vs. endovascular repair of popliteal artery aneurysm

Surgical repair remains the optimal method to treat a popliteal artery aneurysm.

Popliteal artery aneurysm, or PAA, is the most common peripheral aneurysm, but data on this disease are nonetheless limited. A report from the VASCUNET collaboration of registries showed that 1,471 repairs were performed among a population of 58 million people in eight countries, for a rate of 9.6 per million. Most (72%) were elective, and 78% were open repairs (Eur. J. Vasc. Endovasc. Surg. 2014;47:164-71).

Although the endovascular approach has been increasingly used since 2000, outcomes have varied considerably across studies.

A review of 163 relevant studies from more than 1,600 that have been published since 1994 showed extensive heterogeneity with respect to the inclusion of symptomatic vs. asymptomatic patients, emergent vs. elective cases, poor runoff vs. good runoff, types of stents used, and types of conduits used for open repair. This renders the validity of the meta-analysis of these studies uncertain.

However, based on the few studies with complete data concerning mortality, major adverse events, primary and secondary patency, and limb salvage – with separate analysis for elective and emergency repairs – it appears that the availability of the great saphenous vein (GSV) is an important determinant when deciding whether to perform an open repair, that the posterior approach is preferred (except in cases of aneurysms extending to the adductor canal or trifurcation vessels), and that elective open repair is associated with significantly better outcomes than endovascular repair on a number of measures.

For example, no difference was seen in mortality in 23 selected studies, but the 3-year primary patency was significantly better with open repair (85% vs. 58%), while the 3-year rate of major adverse events, including mortality, major amputation, graft thrombosis, and reintervention was lower (20% vs. 38%).

These findings were confirmed in a study of 149 elective repairs. In that series, major adverse events were significantly more common in endovascular vs. open cases (hazard ratio, 2.1), and poor runoff was associated with a higher risk of major adverse events regardless of the technique used (J. Vasc. Surg. 2014 60:631-8.e2).

A recent decision analysis model applied to patients with asymptomatic PAA also demonstrated that elective open repair with a GSV bypass is the preferred treatment for all outcomes, with stenting recommended in high-risk patient or those without a suitable vein (J. Vasc. Surg. 2014;59:651-62).

One concern with endovascular repair is the risk of stent fracture, particularly in younger more active patients as data suggest that the more active the individual, the greater the risk of stent fracture. In one study, the frequency of stent fracture in younger patients was 17%. This suggests that stenting is probably not the best technique to be used in active individuals.

The current data suggest that the best outcomes are achieved with elective open repair using the great saphenous vein. However, patency rates above 80% at 2 years have been reported recently for elective endovascular repair associated with dual antiplatelet therapy, thus it is possible that new stent grafts and best medical therapy could improve the results of endovascular repair.

Open repair also appears to be best in most emergent cases. In one meta-analysis of 11 studies involving 223 patients, graft thrombosis occurred in 8% of open cases vs. 53% of endovascular cases, patency at 6 months was 82% vs. 68%, and reintervention rates were 25% vs. 43% in open vs. endovascular cases, respectively.

Thrombolysis was associated with a significant improvement in 1-year primary graft patency rates compared with surgery alone, but this did not affect the amputation rate, and endovascular repair does not appear to improve the severe prognosis of acute ischemia in patients with PAA.

Despite the deceiving results of endovascular repair in those with acute ischemia, this technique could, however, be very useful in other emergent situations. For example, very old patients presenting with a ruptured PAA and a good runoff could benefit from an endovascular repair.

In summary, no level 1 evidence regarding open vs. endovascular repair for popliteal artery aneurysms can be obtained; most studies are retrospective and lack important characteristics. Based on the data that do exist, however, open repair with a vein bypass appears to be the best technique for most patients with PAA. Stenting should be reserved for high-risk and elderly asymptomatic patients. As for those with acute limb ischemia, no strong recommendation can be made based on the available data.

Dr. Jean-Baptiste Ricco is professor and chief of vascular surgery at the University of Poitiers, France. He reported having no disclosures. This and the accompanying perspective by Dr. Marone were based upon their live debate at the 2014 Vascular Annual Meeting.