Realistic expectations for patients with stent-graft treatment of abdominal aortic aneurysms. Results of a European multicentre registry

Objective: the outcomes for patients after endovascular treatment of abdomi nal aortic aneurysm (AAA) are determined primarily by the endpoints of deat h and endoleaks, the latter representing continued risk of rupture. The dat a of a multicentre registry were analysed with regard to the early outcome of stent-graft procedures for AAA and the complications associated with thi s treatment. In addition, the results during follow-up were analysed by det ermining mortality and endoleak development as separate endpoints and as a combined endpoint defined as endoleak;free survival. Setting: 38 European institutions is of Vascular Surgery collaborating in a multicentre registry project. Patients and methods: 899 patients with AAA underwent between May 1994 and March 1998 elective endovascular repair (818 men and 81 women; mean age 69 years). 80 (8.9%) of the patients had medical conditions that excluded them from open repair. 818 (91%) of patients had a bifurcated device, 63 (7%) h ad a straight tube graft, and only 18 (2%) had art aorto-uni-iliac device. Clinical examination and contrast-enhanced computed tomography was performe d at fixed follow-up intervals to assess increase or decrease of the maximu m transverse diameter (MTD). Endoleaks observed at follow-rip were discrimi nated into persistent endoleak and temporary endoleak. The latter is define d as single time observed endoleaks or with two or more negative imaging st udies between observed endoleaks. Life-table analyses were risen to calcula te fire rates of freedom-from-endoleak (no endoleak at any time), freedom-f rom-persistent endoleak (no persistent endoleak), patient survival, and per sistent-endoleak-free-survival. Results: the median follow-up of this patient series was 6.2 months. The ra tio between observed and expected follow-up data was 82% for the overall fo llow-up period. However, at 18 months of follow-up this rate was only 45%. The number of patients followed during this period was sufficient to allow statistically meaningful assessment. The MTD in patients with temporary end oleaks demonstrated a significant decrease at 6 to 12 months compared to pr eoperative values (mean 57 and 53 respectively, p = 0.004). in patients wit h persistent endoleaks there was no change between the preoperative and 6-m onth MTD (mean 57 and 60 mm respectively). Ar 6 and 18 months freedom-from- endoleak was 83% and 74% and freedom-from-persistent endoleak was 93% and 9 0%, respectively. The 18-month cumulative patient survival was 88% and the main outcome measure, the persistent endoleak-free-survival was 79%. Conclusions: the MTD decreases in patients with temporary endoleak, but not in patients with persistent endoleak. Therefore, the use of the rate of fr eedom-from-persistent endoleak, reflecting absence of persisting endoleaks to estimate the prognosis with regard to the AAA, is justified. Determining persistent endoleak-free survival appears a rational approach to provide a realistic outlook for patients with stent-grafted AAA. The observed 18-mon th endoleak-free survival reflects a satisfactory mid-term result.