title: Feasibility of therapeutic pneumoperitoneum in a large animal model using a microvaporisator.
abstract: BACKGROUND
  Multimodal therapy is used increasingly in advanced gastrointestinal tumors. Potential benefits of using an intraoperative adjuvant therapy during laparoscopy for cancer have been documented in animal studies. The aim of this study was to develop a device that could deliver such an intraoperative drug therapy.
  
  
  METHODS
  We developed a micropump suitable for minimally invasive surgery procedures that allowed microdroplets of therapeutic substance to be distributed into the pneumoperitoneum (CO2), creating a "therapeutic pneumoperitoneum." A closed-loop control system regulates drug delivery according to the gas flow. In vitro, the micropump is able to aerosolize various aqueous and ethanol solutions, including cytostatic and bacteriostatic drugs and adhesion-modulating agents. The size of the microdroplets has been optimized to prevent visual artifacts.
  
  
  RESULTS
  The micropump was tested in an animal model (pig). The system was inserted into a 5-mm trocar. After insufflation of a 12-mm CO2 pneumoperitoneum, laparoscopic sigmoid colon resections could be performed with no special difficulties. No fog developed, and no system-related complication was observed. At autopsy, the active principle was distributed to all exposed peritoneal surfaces.
  
  
  CONCLUSIONS
  As opposed to conventional peritoneal washing, therapeutic pneumoperitoneum reaches the entire peritoneal surface, allowing an optimal drug distribution. Drug diffusion into the tissues is enhanced by the intraperitoneal pressure. Precise determination of the instantaneous and total drug quantity is possible. Therefore, this drug delivery system has several advantages over conventional irrigation. Its potential domains of application are locoregional cancer therapy, prevention of port-site recurrences, immunomodulation, analgesia, peritonitis, and prevention of postoperative adhesions.
authors.affiliation: Digestive Surgery, University Hospital of Geneva, Switzerland.
authors.forename: M A
authors.initials: MA
authors.lastname: Reymond
authors.forename: B
authors.initials: B
authors.lastname: Hu
authors.forename: A
authors.initials: A
authors.lastname: Garcia
authors.forename: T
authors.initials: T
authors.lastname: Reck
authors.forename: F
authors.initials: F
authors.lastname: Köckerling
authors.forename: J
authors.initials: J
authors.lastname: Hess
authors.forename: P
authors.initials: P
authors.lastname: Morel
mesh_terms: D000008:Abdominal Neoplasms / Q000188:drug therapy; D000336:Aerosols; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002245:Carbon Dioxide; D016503:Drug Delivery Systems / Q000295:instrumentation*; D004867:Equipment Design; D005240:Feasibility Studies; D010535:Laparoscopy; D011028:Pneumoperitoneum, Artificial; D013552:Swine; D013654:Taurine / Q000008:administration & dosage / Q000031:analogs & derivatives; D013829:Thiadiazines / Q000008:administration & dosage
chemical_list: D000336:Aerosols; D000970:Antineoplastic Agents; D013829:Thiadiazines; D002245:Carbon Dioxide; D013654:Taurine; C012566:taurolidine