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

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 EUROSTAT collaborators re gistry. Materials and Methods: patient characteristics anatomic features of the aneurysm, type of endovascular device, institutional experience and th e year in which the procedure was performed were related to risk of convers ion. Results: forty-nine patients (2.6%) required conversion. In 38 patients con version was performed during the first postoperative month (primary convers ions) and in 11 patients during follow-up (secondary conversions). Primary conversion was mostly due to access problems and device migration. Secondar y conversions were performed for rupture in six and for a persistent endole ak, with or without aneurysmal growth, in File patients. Patients who were converted were significantly older, had a lower body weight, and had a high er prevalence of chronic obstructive pulmonary disease. Conversion tons ass ociated with shorter, wider infrarenal necks and larger aneurysms. The conv ersion 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 requir ed primary conversion had an 18% mortality rate compared to 2.5% mortality in patients without conversion (p<0.01). Secondary conversion was associate d with a perioperative mortality of 27%, and when performed for rupture 50% . Conclusion: both primary conversion and secondary conversion for rupture ca rry a high operative mortality. Awareness of the risk factors may reduce co nversion rate as well as early and medium term mortality.