A Prevention Protocol Reduces Spinal Cord Ischemia in Patients Undergoing Branched/Fenestrated Endovascular Aortic Repair, Particularly Among High-risk Patients

Spinal cord ischemia (SCI) is a devastating complication associated with repair of thoracoabdominal aortic disease. SCI risk increases with increasing aortic coverage length; therefore, patients undergoing branched/fenestrated endovascular repair (B/FEVAR) are particularly vulnerable. A bundled SCI prevention protocol was previously reported to reduce SCI rates when compared to a historic cohort in a single center study. Accordingly, the purpose of this analysis was to further substantiate and update outcomes associated with the protocol given the routine implementation of this strategy at two institutions (University of Florida [UF] and the University of Alabama at Birmingham [UAB]) since inception. Components of the SCI prevention protocol include selective cerebrospinal fluid (CSF) drainage, specified blood pressure parameters, transfusion goals, and selective pharmacologic adjuncts (naloxone, steroids). This protocol was routinely implemented in May 2015. Patients undergoing B/FEVAR from May 2015 to December 2022 constituted the post-protocol cohort (n = 402) and were compared to the pre-protocol cohort (n = 160; January 2010-April 2015). The primary outcome was SCI incidence, and subgroup analysis was conducted among patients deemed to be high-risk (Crawford extent I-III thoracoabdominal aneurysms [TAAAs]). Survival analysis was conducted using Kaplan-Meier methodology. The pre- and post-protocol cohorts were demographically similar, though a greater proportion of post-protocol patients were ASA class IV (86.1% vs 55.0%; P < .001). TAAA was the most common indication in both groups; however, the pre-protocol cohort had a larger proportion of suprarenal aortic disease, as well as other non-aneurysm-related indications, and underwent significantly fewer staged repairs. CSF drain placement was more common in the post-protocol group, particularly among high-risk patients. SCI occurred in 15.9% of pre-protocol patients vs 2.7% of post-protocol patients (P < .001) (Table I). In high-risk patients, the pre- and post-protocol cohort SCI incidence was 29.4% vs 7.9%, respectively (P < .001). Length of stay (LOS) and 30-day mortality was decreased in the post- protocol cohort (Table I). While the post-protocol group tended toward improved 1-year survival, this was not statistically significant (Fig 1). Among patients experiencing SCI, 1- year mortality was 38.1% and 53.3% in the pre- and post-protocol groups, respectively (P = .46). Implementation of a bundled SCI prevention protocol significantly decreases SCI rates among B/FEVAR patients, which has now been validated at two institutions, with the greatest difference in SCI rates seen among the high-risk patients. While the overall 1- year survival difference was not significantly different between the cohorts, the high mortality rates among patients who experience SCI emphasizes the importance of adhering to preventative measures.TableDemographic and outcome comparison between pre- and post-SCI protocol cohortsVariable, No. (%)Pre-protocol cohort (n = 160)Post-protocol cohort (n = 402)P-valueAge, years72.6 ± 8.572.3 ± 10.7.73Male109 (68.1)294 (73.1).23ASA class 488 (55.0)346 (86.1)<.001Hypertension147 (91.9)361 (89.8).45Chronic renal insufficiency64 (40.0)139 (34.6).23Prior aortic repair69 (43.1)194 (48.3).27Indication<.001 TAAA120 (75.0)331 (82.3) Suprarenal aneurysm26 (16.3)50 (12.4) Dissection4 (2.5)18 (4.5) Other10 (6.3)3 (0.7)Maximum aortic diameter, mm66.4±11.466.6±14.0.92Staged repair2 (1.3)81 (20.1)<.001Urgency<.001 Elective121 (75.6)355 (88.3) Symptomatic/urgent36 (22.5)33 (8.2) Emergent/rupture3 (1.9)14 (3.5)Pre-emptive CSF drain, any indication45 (29.0)121 (30.1).81Pre-emptive CSF drain, Crawford extent I-III TAAA16 (51.6)95 (68.3).07LOS, days5 (4, 10.8)5 (3, 7)<.00130-day mortality10 (6.3)9 (2.2).02Blood transfusion (total LOS), units1.9±3.81.5±3.6.55Postoperative complications67 (41.9)56 (13.9)<.001Any SCI25 (15.9)11 (2.7)<.001SCI presentation Sensory2 (9.1)2 (13.3).68 Paraparesis11 (50.0)10 (66.7).32 Complete paralysis9 (40.9)5 (33.3).64Total protocol elements included3 (2.3, 4)5 (3, 7).02CSF drain.09 None8 (33.3)0 (0) Pre-emptive13 (54.2)9 (81.8) Post-implantation, therapeutic3 (12.5)2 (18.2)SCI status at discharge Unchanged7 (33.3)4 (26.7).68 Improved6 (28.6)3 (20.0).56 Resolved8 (38.1)8 (53.3).36 Open table in a new tab