25. Total psoas area does not associate with perioperative mortality or morbidity after lumbar spine surgery

Abstract

BACKGROUND CONTEXT In various surgical settings, single measures of frailty are increasingly used to guide patient selection and inform risk modification. Since a cardinal aspect of frailty is loss of functional capacity associated with loss of muscle mass, measures of sarcopenia have been looked to as indicators of frailty. Psoas muscle area (TPA) has emerged as a particularly practical and effective measure of sarcopenia. The present study aims to assess the utility of TPA as a predictor of perioperative morbidity and mortality. METHODS A retrospective review was conducted on 367 consecutive patients undergoing lumbar spinal surgery at our institution from January 2016 to February 2017. Demographic information was collected from review of the electronic medical record. Morphometric measurements including vertebral body area and right and left psoas muscle area were recorded by 2 independent readers at the mid-L3 level from MRI or CT within 1 year of index surgery. Outcomes included perioperative adverse events, rehospitalization within 90 days, and 90-day mortality. TPA and TPA indexed to vertebral area were calculated for all patients. RESULTS The overall rate of perioperative complication was 26%, rate of rehospitalization within 90 days was 15%, and 90-day mortality was 0.8%. Age, sex, history of hypertension, hyperlipidemia, diabetes, and former or current smoking were not associated with the incidence of adverse events, rehospitalization or death. Surgical characteristics including fusion type and number of vertebral levels treated were also not significantly associated with morbidity or mortality. Both TPA and TPA indexed to vertebral area did not associate with perioperative adverse events, rehospitalization, or 90-day mortality in both univariate regression and multivariate regression adjusting for age and for sex. Only a history of prior lumbar surgery was significantly associated with perioperative complication (OR 1.67, CI 1.04-2.68, p=0.03). CONCLUSIONS In an adult lumbar spine surgery population, morphometric measurements of TPA and TPA indexed to vertebral area were not associated with perioperative adverse event, rehospitalization, or mortality. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. In various surgical settings, single measures of frailty are increasingly used to guide patient selection and inform risk modification. Since a cardinal aspect of frailty is loss of functional capacity associated with loss of muscle mass, measures of sarcopenia have been looked to as indicators of frailty. Psoas muscle area (TPA) has emerged as a particularly practical and effective measure of sarcopenia. The present study aims to assess the utility of TPA as a predictor of perioperative morbidity and mortality. A retrospective review was conducted on 367 consecutive patients undergoing lumbar spinal surgery at our institution from January 2016 to February 2017. Demographic information was collected from review of the electronic medical record. Morphometric measurements including vertebral body area and right and left psoas muscle area were recorded by 2 independent readers at the mid-L3 level from MRI or CT within 1 year of index surgery. Outcomes included perioperative adverse events, rehospitalization within 90 days, and 90-day mortality. TPA and TPA indexed to vertebral area were calculated for all patients. The overall rate of perioperative complication was 26%, rate of rehospitalization within 90 days was 15%, and 90-day mortality was 0.8%. Age, sex, history of hypertension, hyperlipidemia, diabetes, and former or current smoking were not associated with the incidence of adverse events, rehospitalization or death. Surgical characteristics including fusion type and number of vertebral levels treated were also not significantly associated with morbidity or mortality. Both TPA and TPA indexed to vertebral area did not associate with perioperative adverse events, rehospitalization, or 90-day mortality in both univariate regression and multivariate regression adjusting for age and for sex. Only a history of prior lumbar surgery was significantly associated with perioperative complication (OR 1.67, CI 1.04-2.68, p=0.03). In an adult lumbar spine surgery population, morphometric measurements of TPA and TPA indexed to vertebral area were not associated with perioperative adverse event, rehospitalization, or mortality.