Laparoscopic Surgery: A New Technique to Induce Endometriosis in a Mouse Model

This prospective pilot study was designed to induce endometriosis in a mouse model using laparoscopy, a less invasive and more precise approach than laparotomy. We aimed to achieve a peritoneal implant rate of at least 50% by varying both duration of anesthesia and intra-abdominal insufflation pressure.

Female BALB/cANnCrl mice in metestrus or diestrus were used as donors (n = 5) or recipients (n = 20) of uterine transplant tissue. Each recipient mouse was laparoscopically inoculated with 10 uterine pieces (range: 10-12) from donor mice into the abdominal cavity. Before starting the study, recipient mice were randomly assigned to 4 groups with variable duration of anesthesia (ketamine/xylazine or pentobarbital) and variable intra-abdominal pressure (5 or 15 mm Hg). One week after laparoscopy, endometriosis incidence and peritoneal implant take rate were documented visually during laparotomy. The retrieved lesions were histologically analyzed.

Laparoscopic inoculation of uterine pieces in recipient mice resulted in an endometriosis incidence of 100% (20/20 animals) and an individual peritoneal implant take rate of 60% (121/206), ranging from 17% (2/12) till 83% (10/12), without differences between the 4 subgroups, and with a histological confirmation rate of 92% (58/63).

To the best our knowledge, this is the first report showing that endometriosis can be induced by laparoscopic surgery in rodents, with a 100% incidence and a median peritoneal implant take rate of 60%. This laparoscopic model offers important advantages over traditional laparotomy models that are limited by surgery-associated trauma and/or adhesion formation.