Background: Skeletal muscle depletion has been shown to be an independent risk factor for poor survival in various diseases. However, in surgery, the significance of other body components including visceral and subcutaneous adipose tissue remains unclear.
Methods: This retrospective study included 250 adult patients undergoing living donor liver transplantation (LDLT) between January 2008 and April 2015. Using preoperative plain computed tomography imaging at the third lumbar vertebra level, skeletal muscle mass, muscle quality, and visceral adiposity were evaluated by the skeletal muscle mass index (SMI), intramuscular adipose tissue content (IMAC), and visceral to subcutaneous adipose tissue area ratio (VSR), respectively. The cutoff values of these parameters were determined for men and women separately using the data of 657 healthy donors for LDLT between 2005 and 2016. Impact of these parameters on outcomes after LDLT was analyzed.
Results: VSR was significantly correlated with patient age (P = 0.041), neutrophil-lymphocyte ratio (P < 0.001), body mass index (P < 0.001), and SMI (P = 0.001). The overall survival probability was significantly lower in patients with low SMI (P < 0.001), high IMAC (P < 0.001), and high VSR (P < 0.001) than in each respective normal group. On multivariate analysis, low SMI (hazard ratio [HR], 2.367, P = 0.002), high IMAC (HR, 2.096, P = 0.004), and high VSR (HR, 2.213, P = 0.003) were identified as independent risk factors for death after LDLT.
Conclusions: Preoperative visceral adiposity, as well as low muscularity, was closely involved with posttransplant mortality.
The authors propose skeletal muscle mass index, intramuscular adipose tissue content, and visceral to subcutaneous adipose tissue ratios to enhance the quantitative assessment of frailty in liver transplant candidates. These variables had predictive value of clinical outcomes is a series of recipients of living donor liver transplantation.
1 Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Received 1 July 2016. Revision received 25 October 2016.
Accepted 31 October 2016.
The authors declare no funding or conflicts of interest.
All authors participated in final approval of the article.
Y.H., T.K., and S.U. participated in the conception and design. Y.H., S.O., A.K., H.S., S.Y., N.K., and H.O. participated in the acquisition of data. Y.H. and T.K. participated in the analysis and interpretation of data. Y.H. and T.K. participated in the drafting of manuscript. S.O., A.K., H.S., S.Y., N.K., H.O., and S.U. participated in the revision of the article.
Correspondence: Toshimi Kaido, MD, PhD, Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. (firstname.lastname@example.org).
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