Back to 2024 Abstracts
Evolving Practices of Spinal Drain Use for F/BEVAR Patients in the US-ARC
Angela D Sickels1, Zdenek Novak
1, Andres Schanzer
2, Mark A Farber
3, Matthew P Sweet
4, Gustavo S Oderich
5, Carlos Timaran
6, Darren B Schneider
7, Matthew J Eagleton
8, Warren Gasper
9, W. Anthony Lee
10, Adam W Beck
1
1University of Alabama at Birmingham, Birmingham, AL, 2University of Massachusetts Memorial Health, Worcester, MA, 3University of North Carolina, Chapel Hill, NC, 4University of Washington, Seattle, WA, 5University of Texas Health Science Center at Houston, Houston, TX, 6University of Texas Southwestern Medical Center, Dallas, TX, 7University of Pennsylvania, Philadelphia, PA, 8Massachusetts General Hospital, Boston, MA, 9 University of California, San Francisco, San Francisco, CA, 10 Baptist Health Heart and Vascular Care, Boca Raton, FL
BACKGROUND: Spinal cord ischemia (SCI) can be a devastating complication of endovascular aortic repair. Patients with thoracoabdominal aortic aneurysms (TAAA) are at increased risk due to the extensive aortic coverage required for TAAA exclusion. Many centers performing fenestrated/branched endovascular aortic repair (F/BEVAR) have developed standardized protocols for the prevention and mitigation of SCI, which often include cerebrospinal fluid drain (CSFD) use as one component. However, there is currently no evidence for the degree to which CSFDs can prevent/mitigate SCI. Furthermore, there are no standard criteria guiding which patients receive a CSFD. Recent literature has suggested that a more restrictive use of CSFDs in F/BEVAR patients may be warranted in the elective setting, limiting their use to only patients considered anatomically high-risk. Additionally, the use of staging and adjunctive techniques such as minimally invasive staged segmental artery embolization and temporary aneurysm sac perfusion to stimulate a more robust spinal collateral circulation before definitive repair have been reported to be of benefit in prevention of SCI. Here, we sought to evaluate and analyze the practices surrounding CSFD use concurrently with rates of SCI occurrence, recovery, and CSFD complications in patients undergoing F/BEVAR in the United States Aortic Research Consortium (US-ARC) over time.
METHODS: We conducted a retrospective analysis of the US-ARC registry. This prospectively maintained database consists of patients receiving a custom F/BEVAR under individual physician sponsored investigational device exemptions at ten high-volume aortic centers. Patients included underwent elective F/BEVAR at a US-ARC center from January 2011-April 2024. Patients were excluded if enrolled under compassionate use exemption (N=40), if designated ‘postoperative prophylactic’ drain placement (as the clinical circumstances surrounding this were unclear) (N=19), if there was no CSFD/SCI information available (N=430), if the case was nonelective (N=144), or if undergoing the index procedure prior to 2011 (N=75). Patterns of CSFD use, rates of SCI and recovery, and CSFD complications were analyzed by year. SCI was defined as paralysis or paraparesis. Subanalyses were stratified by Crawford extent (CE) classification based on the length of aortic device coverage, with high-risk patients defined as CE I-III. Eras of repair were divided into early (2011-2013), mid (2014-2021), and late (2022-2024) based on the publication of influential papers which changed US-ARC practices. To further characterize the relationship between SCI and CSFD use, patient cohorts were separated by prophylactic CSFD (N=949), therapeutic CSFD (N=27), and no CSFD (N=1609) use. A primary composite variable consisting of any SCI, major CSFD complication, or intracerebral hemorrhage was designated as the primary outcome. A major CSFD complication was defined as epidural or subdural hematoma, subarachnoid/intraventricular hemorrhage, or meningitis. Multivariable logistic regression was performed to determine variables significantly associated with SCI and with the primary composite outcome, with variables of p<0.1 significance on univariate analysis included in the multivariable regression model. Variables included had missingness <10% and it should be noted that given the addition of variables after initial construction of the database, not all patients have data available for every variable.
RESULTS: Among 2,585 patients 196 (7.6%) experienced the primary composite outcome and 160 (6.2%) experienced SCI. The rate of the primary composite outcome and any SCI event gradually declined over time, from a maximum of 25.0% (5 patients), both primary composite and SCI) in 2011 to 2.8% (11 patients) and 2.3% (9 patients) in 2023, respectively. Concurrently, the use of prophylactic CSFD declined from a maximum of 100% (2011) to a minimum of 10.9% in 2023 without any substantial increase in therapeutic CSFD use (range 0-3.5%) (Figure 1). In high-risk patients (N=1026), 12.9% (N=132) and 10.6% (N=109) experienced the primary composite outcome or any SCI event, respectively. Rates of the primary composite outcome declined from 38.5% in 2013 to 3.0% in 2023. Prophylactic CSFD use in high-risk patients, while nearly universal (92.9-100%) until 2016, has also since been on a continuous decline since, reaching a minimum of 22.6% in 2023 (Figure 1). This subset of patients also saw no increase in therapeutic CSFD use (range 0-5.9%).
The overall incidence of CSFD complications for the entire cohort was 5.6% (145/2585) for any spinal drain complication and 1.4% (36/2585) for a major spinal drain complication. Rates of major CSFD complications by year demonstrated a gradual increase to a maximum of 4% in 2018, followed by a gradual downtrend and have been steadily <2% since 2020. The minor CSFD complication rate reached a maximum of 13% in 2013 followed by a gradual downtrend to now also <2% since 2023.
A total of 614 (23.8%) patients underwent a staged procedure. Rates of staging increased to a maximum of 50.0% in the early era, followed by variable fluctuation then decline to a nadir of 16.9% in 2014. This decline happened concurrently with the greatest rate of decrease in prophylactic CSFD use. In the mid-era, there was a gradual increase in the rate of staged procedures up to 36.8% in 2017 as prophylactic CSFD use continued to downtrend. However, since 2017, the rate of staged procedures has also gradually declined, now steadily just below 20% in the late era (17.8%-19.8% from 2022-2024). Rates of patients who had either a staged procedure or prior aortic repair (and thus were functionally staged) (N=1531) mirrored a similar trend as staged patients alone, the minimum of which occurred in 2013 at 41.9%, gradually increased to 67.3% in 2018, and have been consistently between 53.1% and 58.7% in the late era. While the rates of staging and staging/prior aortic repair were greater for high-risk patients compared to the overall cohort (82.7% vs. 59.2%), the trends over time were similar. In the late era, 31.8-39.4% of high-risk patients were staged and 80.8-83.1% were staged or had a prior aortic repair.
Among patients experiencing SCI, the degree of SCI resolution (none, partial, or complete) was not significantly different among patients with a prophylactic CSFD (N=94, 45.7% with complete resolution), therapeutic CSFD (N=23, 43.5% with complete resolution) or no CSFD (N=21, 42.9% with complete resolution) (p=0.11, Table 1). Among patients receiving a therapeutic CSFD, 91.3% experienced at least partial SCI resolution (Table 1). Rates of major CSFD complications did not differ between the prophylactic and therapeutic CSFD cohorts (13.4% vs 12.0%, respectively, p=0.85). Examining CSFD complication rates in more granular detail revealed significant differences only in rates of subdural hematomas (0% vs 4.0%, respectively, p=0.03) and catheter fracture requiring removal (0% vs 4.0% respectively, p=0.03) (Table 1).
Multivariable logistic regression revealed CE I (OR 2.58 (1.25-5.33), p=0.01), II (OR 3.64 (2.37-5.61), p<0.001) and III (OR 2.61 (1.63-4.18), p<0.001) TAAA, and age 70-79 vs <60 years (OR 2.49 (1.11-5.56), p=0.03) to be significantly associated with the primary composite outcome, while juxtarenal aneurysms (OR 0.40 (0.17-0.9), p=0.03) and procedures performed during the mid (OR 0.36 (0.20-0.63), p<0.001) and late (OR 0.12 (0.06-0.23), p<0.001) eras of repair were protective factors. Examining high-risk patients in isolation, age 70-79 vs. <60 years (OR 2.31 (1.02-5.22), p=0.05) was found to be significantly associated with the primary composite outcome while the mid (OR 0.41 (0.19-0.85), p=0.02) and late eras of repair (OR 0.11 (0.04-0.27), p<0.001) were found to be protective.
CONCLUSIONS: Despite declining prophylactic CSFD use in FEVAR patients over the past decade, rates of SCI have continued to improve. While we expected a reciprocal increase in the rate of staged procedures as an additional method to stimulate the spinal collateral network, rates of functional staging (i.e., those undergoing a staged procedure or with a prior aortic repair) have maintained stability since 2018, even in the setting of declining prophylactic CSFD use. Rates of major CSFD complications have remained low, <2% in the modern era, though are now comparable to contemporary SCI rates. Trends in prophylactic CSFD use, SCI rates, and staging are maintained even for anatomically high-risk patients, though these findings should be interpreted in the context of additional strategies implemented for SCI prevention, which are not necessarily captured in registry data. Furthermore, there were no significant differences in the rates of SCI recovery or major CSFD complications between patients in whom a prophylactic, therapeutic, or no CSFD is placed. Therefore, prophylactic CSFD use may not be justified in this patient population in the setting of comprehensive SCI prevention protocols.
Back to 2024 Abstracts
