The Association of Sarcopenia and ASA Score to Spinal Cord Ischemia in Patients Treated With the t-Branch Device.

Abstract

Sarcopenia has been identified as an independent predictor of mortality in patients with infrarenal abdominal aortic aneurysm and may also affect outcomes in patients with complex aortic pathologies. The aim of this study was to assess sarcopenia, combined with the American Society of Anesthesiologists (ASA) score, as predictors for spinal cord ischemia (SCI) in patients treated with the t-Branch off-the-shelf device. A single-center retrospective observational study was conducted including elective and urgent patients managed with the t-Branch device (Cook Medical, Bjaeverskov, Denmark) between January 1, 2018, and September 30, 2020. Data were collected according to the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement. The psoas muscle area (cm2) and attenuation (Hounsfield units, HU) were measured in the arterial phase of the pre-operative computed tomography angiography for each patient. The lean psoas muscle area (LPMA) was used to stratify patients into 3 groups, and further stratification was performed with a combination of the ASA score and LPMA. Eighty patients were included (mean age at 71±9 years; 62.5% males). Thoracoabdominal aneurysms were managed in 72.5% of cases (42.5% for type I-III). Thirty-seven (46%) were treated urgently. Eleven patients died within 30 days (14%). Twelve patients (15%) presented SCI of any severity. Among the LPMA groups, the only statistically significant difference was recorded in age; group 3 was older compared with groups 1 and 2 (67.1 years vs 72.1 years vs 73.5 years, p=0.004). After ASA combined LPMA categorization, 28 patients were considered as low risk, 16 as moderate risk, and 36 as high risk. A statistically significant difference was recorded in terms of SCI (3.5% [1/28] in low risk vs 12.5% [2/16] in moderate risk vs 25% [9/36] in high risk, p=0.049). Multivariate analysis showed that moderate-risk patients were at risk to evolve to SCI (p=0.04). Low-risk patients, with ASA score I-II or LPMA>350cm2HU, are at lower risk for developing SCI after BEVAR using the t-Branch device. Patients' stratification according to the combination of ASA score and psoas muscle area and attenuation may identify a group at higher risk of SCI after branched endovascular aneurysm repair. Sarcopenia has been identified as a factor of increased mortality in patients managed for aortic aneurysm repair. However, significant heterogeneity has been recorded in the tools assessing its presence. In this analysis, an already used method, combining the ASA score and psoas muscle area and attenuation, has been used to assess the impact of sarcopenia in patients managed with the t-branch device. This analysis showed that patients at low risk, with an ASA score I-II or LPMA>350cm2HU were at lower risk to evolve spinal cord ischemia. Along this line, sarcopenia may be a valuable marker for the prediction of perioperative adverse events , other than mortality, in patients managed using complex endovascular repair.