Selection of patients with malignant ascites for a peritoneovenous shunt.

Twenty-two patients with intractable malignant ascites who received a peritoneovenous shunt were studied. We found that the peritoneovenous shunt functioned longer in patients whose ascitic fluid was negative for malignant cells. The median shunt survival in alive patients in the negative cytologic group was 140 days compared to 26 days in the positive cytologic group (P = 0.01). The overall survival of these patients was poor, with a median of 32 days. Median survival of patients with positive cytologic results (26 days) was significantly worse than for the cytologically negative group (80 days; P = 0.05). The incidence of tumor emboli, confirmed at autopsy, was estimated to be about 5%. Seventy-five percent of all complications occurred in the group of patients with a positive cytologic result. We conclude that a positive ascites fluid cytologic finding is a relative contraindication to placement of a peritoneovenous shunt since this is associated with early shunt failure, postoperative coagulopathy, infection, and tumor emboli. However, since the serious complication rate is only 4% and tumor emboli rate 5%, peritoneovenous shunting in symptomatic patients with cytologically negative malignant ascites is a useful palliative procedure.