Correlation Between Lean Psoas Muscle Area and Incidence of Morbidity and Mortality in Patients Undergoing Thoraco-Abdominal Aortic Aneurysm Open Surgery

Objective: Sarcopenia is gaining interest in the pre-operative evaluation of patients with thoraco-abdominal aortic aneurysm (TAAA). Lean psoas muscle area (LPMA) has emerged as a way to measure sarcopenia and is a possible predictor of outcomes in endovascular TAAA repair. The aim of this study was to analyse the correlation between LPMA and outcomes of open TAAA repair. Methods: Between 2018 and 2022, all consecutive elective patients who underwent open TAAA repair with an available adequate pre-operative computed tomography angiogram (CTA) were analysed retrospectively. The CTA data were used to measure LPMA. Pre- and post-operative variables were collected from all patients. Primary endpoints were death and major adverse events (MAEs) at 30 days and 90 days. The secondary endpoint was follow up mortality rate. Primary and secondary endpoints were correlated with LPMA. Results: A total of 179 patients were included, and 61.5% (110/179) were treated for extent II and III TAAA. Death at 30 days and 90 days was 6.1% and 8.9%, respectively. At a median follow up of 38 months (range: 12 – 60), the mortality rate was 17.2%. The proportion of patients with MAE occurrence at 30 days and 90 days was 29.1% and 37.4%, respectively. The median LPMA was 330 cm2/Hounsfield unit (HU) (interquartile range 264, 442) and was significantly higher in men than in women (p =.001). Patients were divided according to the LPMA value into sarcopenic (< 350 cm2/HU) and non-sarcopenic (> 350 cm2/HU) groups, and in four quartiles. No statistically significant correlation between LPMA and death or MAEs was observed at 30 days and 90 days, and at follow up, but a trend towards an increased mortality rate was observed in patients with sarcopenia at 30 days (10%; 9/90) compared with patients without sarcopenia (2.2%, 2/89) (p =.059). Conclusion: In this series of patients who underwent open TAAA repair, LPMA was found to be ineffective as an independent predictor of morbidity and mortality. Further studies are needed to clarify the role of this parameter as a predictor of adverse outcomes.