A systematic review and meta-analysis of the occurrence of spinal cord ischemia after endovascular repair of thoracoabdominal aortic aneurysms

Abstract

Objective: The rate of endovascular repair of thoracoabdominal aortic aneurysms (TAAA-ER) has increased considerably in recent years. Although the mortality and morbidity rates have improved, the incidence of spinal cord ischemia (SCI) has not declined significantly. The aim of the present systematic review and meta-analysis was to examine the SCI rates with respect to the efficacy of the different approaches.

Methods: Cohort studies and case series (>20 patients) reporting SCI rates after TAAA-ER were eligible for inclusion. The primary outcome measure was the evaluation of SCI. The moderators considered were primarily the staged vs nonstaged approach, the use of cerebrospinal fluid drainage (CSFD), and TAAA extension. The permanent SCI and mortality rates were extracted.

Results: A total of 27 studies with 2333 patients were included in the meta-analysis. The pooled estimate for SCI was 11% (95% confidence interval [CI], 8%-15%; I², 79%). For extent I, II, III, and V TAAA, the pooled SCI rate was 13% (95% CI, 10%-17%; I², 69%). For extent IV TAAA, the pooled SCI rate was 6% (95% CI, 3%-10%; I², 62%). A staged TAAA-ER approach was used in 20 studies and a nonstaged approach in 8 (1 study had included both). A lower pooled SCI rate was identified after staged than after nonstaged TAAA-ER (9% vs 18%, respectively; P = .02). Staging was accomplished in >1 month in nine studies and ≤1 month in two studies, leading to similar SCI rates (7% vs 11%, respectively; P = .26). The method of staging (thoracic endoprosthesis or temporary aortic sac perfusion) did not affect the SCI rates. Symptomatic CSFD was associated with a similar pooled rate of SCI compared with prophylactic CSFD (10% vs 10%, respectively; P = .99). The pooled permanent SCI rate was 6% (6% for extent I, II, III, and V TAAA; and 3% for extent IV TAAA). The pooled rate of 30-day mortality was 7%, with a similar incidence for the staged and nonstaged approaches (6% vs 9%, respectively). Interstage mortality was reported in 9 studies, with a pooled estimate rate of 1.6%.

Conclusions: SCI had occurred in 11% of TAAA-ER, and one half of these cases were permanent. A staged approach can reduce SCI rates independently of the timing and method adopted. The overall mortality rate for staged TAAA-ER was 7%, with one fifth of the deaths (1.6%) occurring between stages.

Keywords: Endovascular repair; Spinal cord ischemia; TAAA; Thoracoabdominal aortic aneurysm repair.