Laparoscopic lavage reduces peritoneal inflammatory proteins independent of gas, fluid, or pressure
Erik Sinclair, Lena Öhman, Koen Simons, Maria Magnusson, Mattias Prytz, Eva HaglindAbstract
Introduction
Laparoscopic lavage is an established alternative to resection in perforated diverticulitis with purulent peritonitis, but the mechanism of action remains unclear. It is unknown whether its effect is primarily explained by mechanical washout or influenced by procedural factors such as insufflation gas, lavage fluid, and intra-abdominal pressure. This study aimed to determine the relative contribution of lavage and procedural factors to the early peritoneal inflammatory response.
Methods
In a controlled experimental study, 110 rats with cecal ligation and puncture–induced peritonitis, with 15 sham controls, were randomized to lavage or no lavage, with variation in gas (carbon dioxide versus helium), fluid (saline versus buffered solution), and pressure (2 versus 8 mmHg). Peritoneal fluid and serum were analyzed 1-hour post-intervention using a 92-protein panel. Proteomic patterns were assessed using principal component analysis (PCA), and differential protein abundance was evaluated using mixed linear models.
Results
In peritoneal fluid, PCA showed clear separation between lavage-treated and non-lavaged animals, independent of gas, fluid, or pressure. Lavage was associated with a broad reduction in inflammatory protein levels, including cytokines, chemokines, and growth factor signalling proteins, while only a few proteins increased. In serum, no separation was observed.
Discussion
Lavage was the dominant driver of reduced peritoneal inflammatory protein levels, with no clear effect of procedural factors. The findings support mechanical clearance as the primary mechanism and indicate that lavage is robust across procedural settings. They also suggest that lavage volume may be an important determinant of treatment effect.