Serious adverse events were significantly more frequent in the SR group than in the PRFA group (6/69 versus 3/ 162; P = 0.023). Serious adverse events in the SR group were as follows: bile leakage (2 patients); refractory ascites (2 patients); acute respiratory distress syndrome (ARDS) (1 patient); and massive gastrointestinal bleeding (1 patient). Serious adverse events in the PRFA group were as follows: biloma (1 patient); refractory ascites (1 patient); and intra-abdominal bleeding (1 patient).