Psoas Muscle Area As A Prognostic Factor For Survival In Patients Undergoing EVAR Conversion

Abstract

INTRODUCTION AND OBJECTIVES EVAR conversion (EVAR-c) is technically complex and physiologically demanding. Measures to quantify surgical frailty preoperatively may be useful prior to offering EVAR explant. There is data supporting psoas muscle area (PMA) as a prognostic factor in fenestrated endovascular and open AAA repairs. The purpose of this analysis was to use PMA as an objective measure of frailty and to determine its utility as a predictor of survival for EVAR-c. METHODS A retrospective single-center review of all AAA repairs was performed (2002-2019) and EVAR-c procedures were analyzed (n=153).Cross-sectional area of the psoas at the mid-body of the L3 vertebrae were measured. The lowest tertile of PMA in all patients was used as a cutoff value for low PMA and these patients were compared to “non-low” PMA. RESULTS Patients with low PMA tended to be older(77vs72,p=.002),less likely to be male(73%vs95%,p<.001),and have lower BMIs(26vs29%,p=.002). Time to conversion, total number of EVAR reinterventions and elective presentation as an indication for repair were similar, however; patients with low PMA had larger aneurysms(8.3vs7.5cm,p=.01)and increased post-EVAR sac growth(2.3vs1cm,p=.005). Inpatient mortality was significantly increased for those with low PMA(16%vs5%, p=.02)as well as the total number of complications (1.5±1.9vs0.9±1.5).Although MACE and need for inpatient dialysis were similar, those with low PMA had a four-fold increase in requiring dialysis at discharge(18%vs4%,p=.01).Long-term mortality was significantly reduced in those with low PMA at 68%,55%and 40% at 1,3 and 5 years, respectively, compared with 81%,69%and 69%(p=.049). CONCLUSIONS In patients with low PMA, higher complications, increased perioperative mortality and worse long-term survival may be expected. Time to conversion and endovascular remediation are equivalent but rates of sac growth and overall AAA diameter are increased. PMA evaluation offers a potential to stratify which patients may have worse short-term and late outcomes undergoing EVAR-c. EVAR conversion (EVAR-c) is technically complex and physiologically demanding. Measures to quantify surgical frailty preoperatively may be useful prior to offering EVAR explant. There is data supporting psoas muscle area (PMA) as a prognostic factor in fenestrated endovascular and open AAA repairs. The purpose of this analysis was to use PMA as an objective measure of frailty and to determine its utility as a predictor of survival for EVAR-c. A retrospective single-center review of all AAA repairs was performed (2002-2019) and EVAR-c procedures were analyzed (n=153).Cross-sectional area of the psoas at the mid-body of the L3 vertebrae were measured. The lowest tertile of PMA in all patients was used as a cutoff value for low PMA and these patients were compared to “non-low” PMA. Patients with low PMA tended to be older(77vs72,p=.002),less likely to be male(73%vs95%,p<.001),and have lower BMIs(26vs29%,p=.002). Time to conversion, total number of EVAR reinterventions and elective presentation as an indication for repair were similar, however; patients with low PMA had larger aneurysms(8.3vs7.5cm,p=.01)and increased post-EVAR sac growth(2.3vs1cm,p=.005). Inpatient mortality was significantly increased for those with low PMA(16%vs5%, p=.02)as well as the total number of complications (1.5±1.9vs0.9±1.5).Although MACE and need for inpatient dialysis were similar, those with low PMA had a four-fold increase in requiring dialysis at discharge(18%vs4%,p=.01).Long-term mortality was significantly reduced in those with low PMA at 68%,55%and 40% at 1,3 and 5 years, respectively, compared with 81%,69%and 69%(p=.049). In patients with low PMA, higher complications, increased perioperative mortality and worse long-term survival may be expected. Time to conversion and endovascular remediation are equivalent but rates of sac growth and overall AAA diameter are increased. PMA evaluation offers a potential to stratify which patients may have worse short-term and late outcomes undergoing EVAR-c.