Minimally invasive surgery and oxidative stress response: what have we learned from animal studies?

Oxidative stress (OS) is an integral part of the surgical stress response. Minimally invasive surgery causes less trauma, and thus attenuated stress response is anticipated. However, the pneumoperitoneum or pneumoretroperitoneum is implicated in free radical production. This study reviewed available data on the impact of minimally invasive surgery on OS response of animal models in a systematic way. Databases were searched up to and including January 2010. Most of the studies investigated the effect of pneumoperitoneum on OS, 3 studies investigated the effect of pneumoretroperitoneum on OS. There was a great heterogeneity on experimental conditions including animal models, measured OS markers, methods, and time periods of measurement. Published animal data do not allow a reliable conclusion on the effect of minimally invasive surgery on OS because of the great heterogeneity of experimental conditions. Besides, most studies focus on the effect of pneumoperitoneum, without taking into consideration the effect of less surgical trauma.