Peritonectomy is the surgical removal of the tumor and the destruction either through electrical diathermy or using a high frequency scalpel of all the loci that are visibly infected. The operation is long and complicated and may last from 5 to 12 hours. The admission of the patient to the hospital takes place one or two days before the operation. The preoperative preparation includes a general clinical / laboratory test / interventional / imaging tests of the thorax, the abdomen, the pelvis, such as x-rays, CT scan, PET scan, staging laparoscopy, tumor markers, etc. The day before the surgery, the patient undergoes a bowel preparation with laxatives and preventive antibiotics are administered.