Residual Infrarenal Aortic Neck following Endovascular and Open Aneurysm Repair

BackgroundThe effectiveness of open and endovascular aneurysm repair of aortic abdominal aneurysms (AAAs) can be jeopardised by deterioration of the residual infrarenal neck of the aneurysm.ObjectiveThe study aims to determine the length of the residual infrarenal aortic segment after endovascular and open aneurysm repair.MethodsIn a multicentre randomised controlled trial comparing open and endovascular AAA repair, 165 patients were discharged after open AAA repair (OR) and 169 after endovascular repair (EVAR). Immediately after the operation, surgeons were asked to enter in the case record form whether the level of their anastomosis after open repair was within or beyond 10 mm of the caudal renal artery. Postoperative computed tomography (CT) scans that were obtained within 6 months after surgery were used for comparative analysis. The distance between the caudal renal artery and the proximal anastomosis of the (endo-) graft was measured using axial CT slices and a standardised protocol. CT images were available and suitable for analysis in 156 (95%) of 165 OR patients and in 160 (95%) of 169 EVAR patients. Data are presented as median (range). Differences were analysed using the Mann–Whitney test.ResultsThe distance from the caudal renal artery to the proximal anastomosis was 24 mm (16–30 mm) in the OR group versus 0 mm (0–6 mm) in the EVAR group (p < 0.0001, Mann–Whitney). In 140 of 156 (90%) patients, at least 1 cm of untreated infrarenal neck persisted after OR and in 17 of 160 (10%) after EVAR. In 84 of the 156 open repair patients (54%), the surgeon had indicated that the proximal anastomosis was within 10 mm of the caudal renal artery. Only five surgeons (6%) were accurate in this respect.ConclusionAfter open repair, a longer segment of the infrarenal aortic neck is left untreated compared with endovascular repair and this length is underestimated by most surgeons. Long-term studies are required to determine the consequences of this difference.