Description of a novel approach for intraperitoneal drug delivery and the related device

Two significant limitations of intraperitoneal drug therapy are limited drug distribution and poor penetration into peritoneal nodules. A possible solution is the application of the so-called “therapeutic pneumoperitoneum,” taking advantage of the gaseous nature and the pressure of capnoperitoneum during laparoscopy. Our objective was to develop a device able to apply such therapeutic pneumoperitoneum.

The technology presented here is a spraying device and can be introduced through a trocar. It is driven by mechanical pressure and consists of an injector, a line, and a nozzle. An in vivo experimental study was performed in five pigs. A transvaginal cholecystectomy was performed. At the end of the procedure, a standard dose of methylene blue was sprayed/infused into the abdominal cavity for 30 min (4 test animals w/therapeutic pneumoperitoneum (12 mmHg CO₂) and 1 control animal w/conventional lavage (2 l intra-abdominal volume with extracorporeal circulation)). At the end of the procedure, all animals were autopsied and the peritoneum was analyzed. Outcome criteria were: (1) drug distribution (as assessed by the stained peritoneal surface at autopsy), and (2) diffusion into the peritoneum (presence or not of macroscopic staining of the outer aspect of the peritoneum immediately after surgery).

Stained peritoneal surface was larger after aerosol application compared with peritoneal lavage, and staining more intense. Hidden peritoneal surfaces and the anterior abdominal wall were stained only in the aerosol group. In contrast to peritoneal lavage, the outer aspect of peritoneal membrane was immediately stained after pressurized spraying.

This device and the related approach significantly improve both distribution and penetration of a test substance into the peritoneal cavity in a large animal model. This might be a significant progress in treating intraperitoneal disease, in particular peritoneal carcinomatosis.