Does hyperthermia induce peritoneal damage in continuous hyperthermic peritoneal perfusion?

To investigate the mechanisms of the peritoneal damage induced by continuous hyperthermic peritoneal perfusion (CHPP), protein and fluid loss during and after CHPP and continuous normothermic peritoneal perfusion (CNPP) was studied. Sixteen patients with advanced gastric cancer underwent peritoneal perfusion therapy with saline solution containing 150 to 300 mg cisplatin and 30 to 60 mg mitomycin C for 60 minutes. The temperature in Douglas' pouch was maintained at 42.0 degrees C in the CHPP group (n = 9) and 37.0 degrees C in the CNPP group (n = 7) during perfusion. No statistical differences were found in patients' characteristics between the groups except the maximum temperature in Douglas' pouch during perfusion (41.6 degrees +/- 0.4 degrees C and 37.6 degrees +/- 0.4 degrees C in CHPP and CNPP groups, respectively, p < 0.05). The amount of protein lost into the perfusate was 0.35 +/- 0.22 g/kg body weight in the CHPP group and 0.37 +/- 0.19 g/kg in the CNPP group, showing no significant difference. On the day of surgery, there was no significant difference in the amount of protein and fluid lost through the abdominal drains between the CHPP group (27.9 +/- 24.6 mg/kg/hr and 0.94 +/- 0.63 ml/kg/hr, respectively) and the CNPP group (25.9 +/- 8.6 mg/kg/hr and 1.03 +/- 0.31 ml/kg/hr, respectively). We could not find any significant differences in postoperative protein and fluid loss between the groups on the following 3 days either. We conclude that the peritoneal damage by CHPP is not caused by the hyperthermia but by the peritoneal perfusion with saline solution containing anticancer drugs.