Endovascular versus open repair of asymptomatic popliteal artery aneurysm.

BACKGROUND: Popliteal artery aneurysm (PAA) is a focal dilatation and weakening of the popliteal artery. If left untreated, the aneurysm may thrombose, rupture or the clot within the aneurysm may embolise causing severe morbidity. PAA may be treated surgically by performing a bypass from the arterial segment proximal to the aneurysm to the arterial segment below the aneurysm, which excludes the aneurysm from the circulation. It may also be treated by a stent graft that is inserted percutaneously or through a small cut in the groin. The success of the procedure is gauged by the ability of the graft to stay patent over an extended duration. While surgical treatment is usually preferred in an emergency, the evidence on first line treatment in a non-emergency setting is unclear.

OBJECTIVES: To assess the effectiveness of an endovascular stent graft versus conventional open surgery for the treatment of asymptomatic popliteal artery aneurysms (PAA) on primary and assisted patency rates, hospital stay, length of the procedure and local complications.

SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched June 2014) and CENTRAL (2014, Issue 5). Clinical trials databases were searched for any ongoing or unpublished studies.

SELECTION CRITERIA: All randomised controlled trials (RCTs) comparing endovascular stent grafting versus conventional open surgical repair in patients undergoing unilateral or bilateral prophylactic repair of asymptomatic PAAs were included.

DATA COLLECTION AND ANALYSIS: Data were collected on primary and secondary patency rates (primary endpoints) as well as operating time, the length of hospital stay, limb salvage and local wound complications (secondary endpoints).

MAIN RESULTS: A single RCT was identified that conformed to the inclusion criteria. There was a low risk of selection bias and detection bias. However, the risks of performance bias, attrition bias and reporting bias were unclear from the study. Despite being an RCT, the level of evidence was downgraded to moderate due to the small sample size, resulting in wide confidence intervals (CIs); only 30 PAAs were randomised over a period of five years (15 PAAs each in the groups receiving endovascular stent graft and undergoing conventional open surgery). The primary patency rate at one year was 100% in the surgery group and 93.3% in the endovascular group (P = 0.49). However, the assisted patency rate at one year was similar in both groups (100% patency). There was no clear evidence of a difference between the two groups in the primary or secondary patency rates at four years (13 grafts were patent from 15 PAA treatments in each group). However, the effects were imprecise and compatible with the benefit of either endovascular stent graft or surgery or no difference. Mean hospital stay was shorter in the endovascular group (4.3 days for the endovascular group versus 7.7 days for the surgical group; mean difference (MD) -3.40 days, 95% CI -4.42 to -2.38; P < 0.001). Mean operating time was also reduced in the endovascular group (75.4 minutes in the endovascular group versus 195.3 minutes in the surgical group; MD -119.20 minutes, 95% CI -137.71 to -102.09; P < 0.001). Limb salvage was 100% in both groups. Data on local wound complications were not published in the trial report.

AUTHORS' CONCLUSIONS: Due to the limitations of the current evidence from one small underpowered study, we are unable to determine the effectiveness of endovascular stent graft versus conventional open surgery for the treatment of asymptomatic PAAs. A larger ongoing multicentre RCT should provide more information in the future. However, it seems reasonable to suggest that endovascular repair should be considered as a viable alternative to open repair of PAA on a case by case basis.