Assessing the institutional learning curve for pararenal aortic repair using the fenestrated Anaconda endograft.

Abstract

Custom-made fenestrated aortic endografts allow exclusion of pararenal aortic aneurysms while maintaining blood flow to aortic branches. Meticulous device planning and precise deployment of the main body are essential to allow successful cannulation of the fenestrations. This study investigates whether a learning curve can be observed with more reliable cannulation and connection of fenestrations over time at a single department of vascular and endovascular surgery with multiple surgeons trained to use the device. A retrospective analysis of data from all patients undergoing primary fenestrated endovascular aneurysm repair during the study period was performed. Outcome measures included case volume and average number of fenestrations over time, average fluoroscopy dose area product per calendar year and primary unconnected fenestration and 30-day mortality rates. Between 1 January 2013 and 31 December 2016, 89 patients with no history of endovascular aneurysm repair underwent fenestrated endovascular aneurysm repair at our institution. The number of fenestrations per case increased over time, averaging 2.6 in 2013 and 3.3 in 2016. Primary unconnected fenestration and 30-day mortality rates were 5.6%. Primary-assisted technical success was 93.3%, secondary-assisted technical success was 94.4%. Fluoroscopy dose area product declined over the study period. Thirty-day mortality and primary unconnected fenestration rates did not significantly change over the study period. Albeit the reduction in lethal complications and primary technical success rates were not statistically significant, a lower percentage of unconnected fenestrations and 30-day mortality per calendar year were observed over time. At the same time, an increasing complexity of performed cases, as reflected by an increasing number of fenestrations per case, was observed. Complications associated with this complex endovascular procedure are potentially lethal and remain an unfortunate reality and may not be entirely dependent on overcoming a learning curve. A higher volume of cases performed over the study period and a reduction in fluoroscopy use can be considered a representation of the institutional development and learning curve for the Anaconda fenestrated endograft at a department with prior complex endovascular aortic repair experience, but due to limitations of the current retrospective observation, deserve further consideration in future trials, ideally designed in a prospective fashion.