Purpose: This study was designed to test a rat model in evaluating cryotherapy as a treatment method for downsizing or destruction of uterine fibroids.
Materials and Methods: Fifteen female Eker rats with a mutation on the tuberous sclerosis gene causing fibroids to occur spontaneously were used. Seven, fourteen and twenty-eight days after open surgical cryoablation of uterine fibroids, rats were laparoscopically evaluated and video-recorded. At seven days, intra-abdominal adhesions were evaluated and additional fibroids not originally treated received cryotherapy under laparoscopic visualization. Animals were sacrificed on day 28 after a final laparoscopic visualization of the abdominal cavity. The body of the uterus and horns were removed and stained with hematoxylin and Picrus Sirius red for histological examination.
Results: Fibroids were found in I I of 15 animals. Adhesions to abdominal structures were present in all cryosurgically-treated tissues. Because of the high incidence of concomitant renal cell carcinomas intrinsic to this model, some animals either died or were euthanized before day 28. Only three animals with cryoablated fibroids survived to the end of the study at day 28. Histology of the cryosurgically-treated fibroids showed caseous necrosis, thrombosis of vessels, and fibrosis. When normal uterine tissues were treated, the same observations were found.
Conclusions: This unique animal model proved to be effective in evaluating the effects of cryotherapy for treatment of uterine fibroids. Laparoscopy was an excellent monitoring method for evaluation of the presence of tumors, as well as adhesions, and as an approach for the use of cryotherapy. In this pilot study, cryotherapy demonstrated effectiveness in the destructive management of uterine leiomyomas.
Acknowledgements: This work was supported in part by a grant from the National Science Foundation (NSF/BES-9703326) and a gift from the Candela Corporation.