Risk of spinal cord ischemia after fenestrated or branched endovascular repair of complex aortic aneurysms

Abstract

Objective: The aim of our study was to analyze the incidence of spinal cord ischemia (SCI) in patients presenting with complex aortic aneurysms treated with endovascular aneurysm repair (EVAR) and to identify risk factors associated with this complication.

Methods: A retrospective study was undertaken of prospectively collected data including patients presenting with complex aortic aneurysm (pararenal abdominal aortic aneurysm and thoracoabdominal aortic aneurysm) treated with fenestrated EVAR (F-EVAR) or branched EVAR (B-EVAR). The primary end point was the incidence of SCI and the assessment of any associated factors.

Results: Between January 2011 and August 2017, a total of 243 patients (mean aneurysm diameter, 65.2 ± 15.3 mm; mean age, 72.4 ± 7.5 years; 73% male) were treated with F-EVAR or B-EVAR. Asymptomatic patients were treated in 73% of the cases (177/243, in contrast to 27% urgent), and 52% (126/243) were treated for thoracoabdominal aortic aneurysm (in contrast to 48% for pararenal abdominal aortic aneurysm). F-EVAR (mean number of fenestrations, 3.3/case) and B-EVAR (mean number of branches, 3.7/case) were undertaken in 67% (164/243) and 33% (79/243), respectively. The total incidence of SCI was 17.7% [43/243; paraplegia in 4% (10/243) and paraparesis in 13.7% (33/243)]. Most of the patients with SCI presented with immediate postoperative symptoms (72% [31/43]). A spinal drain was preoperatively placed in 53% (130/243) and was associated with the prevention of SCI (SCI with spinal drainage, 12% [16/130]; SCI without spinal drainage, 24% [27/113]; P = .018). The 30-day mortality rate was 9% (21/243). After multiple logistic regression analysis, SCI was associated with preoperative renal function (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m²: odds ratio [OR], 2.43; 95% confidence interval [CI], 1.18-4.99; P = .016) and the number of vertebral segments covered (SCI with higher position of proximal stent in terms of vertebra: OR, 1.2; 95% CI, 1.1-1.3; P = .000). A similar outcome was derived when the height of the proximal end of the stent graft was replaced by the total length of aortic coverage (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m²: OR, 2.36 [95% CI, 1.11-5.00; P = .025]; SCI with longer length of aortic coverage: OR, 1.01 [95% CI, 1.003-1.009; P = .000]).

Conclusions: The majority of SCI incidence after F-EVAR or B-EVAR of complex aortic aneurysms is manifested immediately postoperatively. The use of preoperative spinal drainage may prevent SCI. Patients with GRF <60 mL/min/1.73 m² and with longer aortic stent graft coverage are at higher risk of SCI.

Keywords: BEVAR; Branched endovascular aneurysm repair; Complex aortic aneurysm; FEVAR; Fenestrated endovascular aneurysm repair; Spinal cord ischemia.