Which factors increase the risk of conversion to open surgery following endovascular abdominal aortic aneurysm repair? The EUROSTAR collaborators.

OBJECTIVE: to identify factors that increase the risk of conversion to open surgery following endovascular repair of abdominal aortic aneurysms (AAAs) and to assess their outcome. Design analysis of 1871 patients enrolled in the EUROSTAR collaborators registry.
MATERIALS AND METHODS: patient characteristics, anatomic features of the aneurysm, type of endovascular device, institutional experience and the year in which the procedure was performed were related to risk of conversion.
RESULTS: forty-nine patients (2.6%) required conversion. In 38 patients conversion was performed during the first postoperative month (primary conversions) and in 11 patients during follow-up (secondary conversions). Primary conversion was mostly due to access problems and device migration. Secondary conversions were performed for rupture in six and for a persistent endoleak, with or without aneurysmal growth, in five patients. Patients who were converted were significantly older, had a lower body weight, and had a higher prevalence of chronic obstructive pulmonary disease. Conversion was associated with shorter, wider infrarenal necks and larger aneurysms. The conversion rate was lower when a team had performed more than 30 procedures, and in procedures performed during the last two years of the study period. The conversion rate was higher with EVT or Talent devices. Patients who required primary conversion had an 18% mortality rate, compared to 2.5% mortality in patients without conversion (p<0.01). Secondary conversion was associated with a perioperative mortality of 27%, and when performed for rupture 50%.
CONCLUSION: both primary conversion and secondary conversion for rupture carry a high operative mortality. Awareness of the risk factors may reduce conversion rate as well as early and medium term mortality. Copyright 2000 Harcourt Publishers Ltd.