Purpose: To identify risk factors for late-occurring branch occlusion following multibranched endovascular repair of thoracoabdominal and pararenal aortic aneurysm.
Method: Out of 120 patients who underwent multibranched endovascular aneurysm repair between September 2005 and May 2013, 100 (78 men; mean age 72.4 ± 7.4 years) met the criteria for inclusion in the current retrospective analysis. Demographic data were gleaned from a prospectively maintained database. Mean aneurysm diameter was 66.7 ± 11.7 mm. Multiplanar reconstructions of postoperative computed tomographic angiography were used to measure 6 parameters of renal branch morphology.
Results: All 100 patients had undergone successful placement of multibranched aortic stent-grafts with a total of 95 celiac branches, 100 superior mesenteric artery (SMA) branches, and 187 renal branches. During a mean follow-up of 25.6 months, there were no stent fractures or stent separations, no SMA occlusions, and only 2 (2.1%) celiac artery occlusions, neither of which required reintervention. In contrast, there were 18 (9.6%) renal branch occlusions in 16 patients, all men (p=0.02). Patients with renal branch occlusions were significantly more likely to have a history of myocardial infarction (p=0.004). The mean renal artery length was significantly greater in the occlusion group compared to the non-occlusion group (47.5 ± 13.6 vs. 39.4 ± 14.2, p=0.03). No other aspect of branch morphology was significantly different between the occlusion and non-occlusion groups.
Conclusion: Renal branch occlusion was by far the commonest late failure mode after multibranched endovascular aneurysm repair. The current study provides no basis for a change in patient selection or stent-graft design, only a change in the components used to construct renal branches. It is too early to tell the effect this will have.
Keywords: aneurysm; endovascular repair; multibranched stent-graft; renal artery; stent-graft; thoracoabdominal.