A low psoas muscle index was associated with a poorer overall survival in patients who underwent percutaneous nephrostomy

Introduction: Malignant ureteral obstruction (MUO) caused by urological, gynecological, and gastrointestinal cancer requires a nephrostomy or ureteral stenting to preserve the renal function and prevent pain and urinary tract infections. Recent investigations have revealed the importance of sarcopenia as a poor prognostic factor in various solid malignancies. This study investigated the importance of sarcopenia as a prognostic factor for MUO patients who have undergone nephrostomy. Materials & Methods A total of 89 percutaneous nephrostomies were created from July 2008 to March 2016 in our institutions. Fifty-seven of these patients had MUO. The psoas muscle volume was calculated at the L3 level using axial computed tomography images obtained prior to nephrostomy. The psoas muscle index (PMI) was calculated using the following formula: (right side psoas muscle area at the level of L3 [mm 2 ]) / (body height [m]) 2 . Results In these 57 patients, 41 cases (71.9%) were male, and 16 (28.1%) were female. The median (mean ± SD) age was 70 (69.0 ± 9.6) years old in males and 68 (66 ± 13.5) years old in females. Primary malignant diseases in MUO were urological cancers in 29 cases (50.9%), gastrointestinal cancers in 19 cases (33.3%), and gynecological cancers in 6 cases (10.5%). There were no marked differences in the OS among malignant diseases. A low PMI was associated with a poor overall survival in male MUO patients. Conclusion The patients who underwent percutaneous nephrostomy with sarcopenia showed a poor overall survival.