Peritoneal carcinosis represents an extremely negative prognostic factor and, in a large number of cases, is rapidly lethal [1,2]. In the literature, a method that appears to be particularly effective in the treatment of this pathology consists of the cytoreduction of all visceral and peritoneal (peritonectomy) macroscopic lesions associated with hyperthermic-antiblastic peritoneal perfusion (HAPP) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].The first perfusion technique was executed making use of a closed method, which includes the suture of the entire laparotomy before starting perfusion. It has the advantage of being quick to perform, but there are several disadvantages:1. The abdominal distribution of the perfusate and the uniformity of the temperature in the cavity are not optimal, even with the use of different tricks [5,12,19,20]. 2. It is not possible to intervene immediately on tubes when an obstruction occurs, making impossible to maintain continuous and high perfusion flows. 3. During chemohyperthermic treatment, there is no visual control of the intestinal loops and of the whole abdominal cavity.In an effort to overcome these drawbacks, first Sugarbaker, and then other investigators, introduced the open technique [21], suspending the skin of the abdominal incision by a self-retaining retractor, in order to obtain a virtual cavity. However, this system presents a number of drawbacks as well:1. The wide abdominal breach results in marked heat dispersion. 2. The high risk that cytostatic drugs may leak out of the patient's abdomen increases the risk of professional exposition.We attempted to identify a perfusion technique designed to overcome the drawbacks of the methods used to date, setting the following goals:1. To reduce heat dispersion 2. To ensure an uniform distribution of the temperature 3. To create a better cavity effect with more efficient intraabdominal flows 4. To control the peritoneal cavity visually during the entire treatment process reducing the risk that chemotherapeutic agents might leak out of the abdomen 5. To develop a system that is rapid and simple to perform To achieve these aims and thereby create the ideal peritoneal perfusion, we developed a semi-closed method.