Participants undergo surgery to remove as much tumor as possible. Part of the intestines, pancreas, stomach or the entire spleen may also be removed if they are affected. During surgery, after the tumor has been removed, two catheters (thin plastic tubes) are placed in the abdomen. A chemotherapy solution containing the anti-cancer drug cisplatin heated to a temperature of about 108.6 degrees (10 degrees above normal body temperature) is then delivered into the abdomen through one catheter and drained through another. During treatment, a drug called sodium thiosulfate is given through a vein to reduce the risk of side effects of cisplatin, particularly kidney damage. After 90 minutes of bathing the abdomen with this solution, the drug is rinsed from the abdomen and the catheters removed. Another small catheter is then placed and left inside the abdomen with one end coming out through the skin. Seven to 12 days after the operation, the anti-cancer drugs 5-FU and paclitaxel are given through this catheter.