Minimally Invasive Segmental Artery Occlusion Prior to Endovascular Repair of Thoraco-Abdominal Aortic Aneurysm to Reduce the Risk of Spinal Cord Injury

Abstract

Introduction - Minimal invasive segmental artery occlusion (MISAO) has been clinically introduced as an entirely endovascular approach to stage the segmental artery (SA) sacrifice in several sessions prior to total endovascular repair (ER) of thoraco-abdominal aortic aneurysm (TAAA) and thereby reduce ischemic spinal cord injury (iSCI) (1,2). The aim of our study was to report on our initial clinical experience and the SCI rates after MISAO and endovascular repair of TAAA. Methods - A cohort of 39 patients (28 men, mean age 68.92±7.56 years) with extensive nonruptured TAAAs and no previous neurological deficit were treated by MISAO followed by fenestrated and multibranched endografting between October 2014 and March 2017. MISAO was performed in local anesthesia with clinical surveillance of the patients ‘neurological functions and hemodynamic stability for at least 48 hours. Final ER was performed after a minimum of one week after the last MISAO session. The main outcomes were the 30-day mortality and the onset of the SCI after ER. Results - The majority of patients (n=36) were treated for atherosclerotic aneurysm, whereas three patients were treated for post-dissection aneurysm. The TAAA distribution was as follow: type I, n= 5; type II, n=9; type III, n=20; type IV, n=5. The maximum aortic diameter was in average 62.74 ± 8.77mm. The mean number of patent SAs per patient was 11±4.5. A total of 245 SAs were occluded by MISAO with each patient having in median 6 coiled SAs (range: 1-19), occluding 75% of direct segmental arterial inflow (Range: 38.89% - 100%). MISAO preconditioning was completed in one (n=15), two (n=17), three (n=3), four (n=3) and five (n=1) sessions prior to TAAA-ER. The maximum number of coiled SAs per session was six and the maximum number of coiled SAs per patient was nineteen. In seventeen patients the inferior mesenteric artery was also coiled. The average interval time between sessions was 63.56 ± 70.69 days. No SCI and no other major complications developed. Minor complications were temporary back pain in eleven patients. After a mean of 77 ± 61.56 days thirty-eight of the patients received total ER of their TAAA. One patient died waiting for ER of TAAA. At 30 days postoperatively, thirty-seven patients were alive and none developed SCI. Conclusion - In our experience, minimal invasive segmental artery occlusion to precondition the paraspinous collateral network is clinically feasible and safe. MISAO followed by aneurysm exclusion may eliminate paraparesis and paraplegia after total endovascular repair of extensive TAAA.