Liver "compliance": a previously unrecognized preoperative predictor of small-for-size syndrome in adult living donor liver transplantation.

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the effect of liver compliance on computed tomography (CT) volumetry and to determine its association with postoperative small-for-size syndrome (SFSS). PATIENTS AND METHODS: Unenhanced, arterial, and venous phase CT images of 83 consecutive living liver donors who underwent graft hepatectomy for adult-to-adult living donor liver transplantation (ALDLT) were prospectively subjected to three-dimensional (3-D) CT liver volume calculations and virtual 3-D liver partitioning. Graft volume estimates based on 3-D volumetry, which subtracted intrahepatic vascular volume from the "smallest" (native) unenhanced and the "largest" (venous) CT phases, were subsequently compared with the intraoperative graft weights. Calculated (preoperative) graft volume-to-body weight ratios (GVBWR) and intraoperative measured graft weight-to-body weight ratios (GWBWR) were analyzed for postoperative SFSS. RESULTS: Significant differences in minimum versus maximum total liver volumes, graft volumes, and GVBWR calculations were observed among the largest (venous) and the smallest (unenhanced) CT phases. SFSS occurred in 6% (5/83) of recipients, with a mortality rate of 80% (4/5). In four cases with postoperative SFSS (n = 3 lethal, n = 1 reversible), we had transplanted a small-for-size graft (real GWBWR < 0.8). The three SFS grafts with lethal SFSS showed a nonsignificant volume "compliance" with a maximum GVBWR < 0.83. This observation contrasts with the seven recipients with small-for-size grafts and reversible versus no SFSS who showed a "safe" maximum GVBWR of 0.92 to 1.16. CONCLUSION: The recognition and precise assessment of each individual's liver compliance displayed by the minimum and maximum GVBWR values is critical for the accurate prediction of functional liver mass and prevention of SFSS in ALDLT.