Measurements of intraperitoneal pressure and the development of a feedback control valve for regulating pressure during flexible transgastric surgery (NOTES)

BackgroundHigh intraabdominal pressures during laparoscopy (greater than 15 mm Hg) are dangerous. Pressures developed during translumenal endosurgery when using flexible endoscopes without feed-back regulation are unknown.ObjectiveTo measure and control intraabdominal pressures during transgastric endosurgery.DesignIn a blinded study, intraabdominal pressures during unregulated transgastric cholecystectomy and tubal ligation were measured by using Veress needles in 5 pigs (group 1). The accessory channel valve of a double-channel gastroscope was modified to allow measurement and control of intraabdominal pressures with a laparoscopic insufflator. This was tested prospectively in another blinded study in 5 pigs (group 2) that underwent identical procedures to those in group 1, with independent Veress needle pressure measurements.SettingThis ethically approved study was performed in an experimental surgical operating theater.InterventionsTransgastric cholecystectomy (n = 4) and tubal resection (n = 6).Main Outcome MeasuresIntraabdominal pressure measurements during transgastric endosurgery, with and without feed-back control.ResultsThe mean (standard deviation) number of pressure measurements per procedure greater than 20 mm Hg was 11 ± 1.41 in group 1 and 0 ± 0 in group 2 (P < .05). Most episodes of high pressure were undetected by the endoscopist, who was blinded to the pressure measurements.ConclusionsUnacceptably high intraabdominal pressures were common during translumenal endosurgical procedures. Feedback pressure regulation through a modified valve prevented overinflation.