Evaluation and comparative analysis of a technique for laparoscopic ovariectomy in rhesus macaques (Macaca mulatta)

Surgical ovariectomy is commonly performed to support studies involving the rhesus macaque (Macaca mulatta). Traditionally, these procedures have been performed via laparotomy. We developed a laparoscopic approach to reduce surgical pain, decrease convalescence times, and reduce the total number of animals necessary to obtain valuable scientific data in studies requiring repeated intra-abdominal access in conjunction with ovariectomy. We used our new technique to perform laparoscopic ovariectomy on 8 adult female rhesus macaques; 2 additional animals underwent ovariectomy via laparotomy; data for these prospective groups were compared with retrospective data from conventionally ovariectomized macaques. The surgical time (ST; mean +/- standard error) for the laparoscopic procedures was 68 +/- 3 min, with a return-to-group time (RTG) of 8 +/- 1 d. In comparison, ST for the retrospective group was 54 +/- 3 min, with a mean RTG of 33 +/- 5 d (range, 15 to 60 d). ST differed significantly between groups. ST for the laparoscopic procedure was longer (mean difference, 14 min; 95% confidence interval, 6 to 21 min), but laparotomized animals consistently had higher RTG (6 d for the prospective group [n = 2] and 25 d for the retrospective group [n = 9]). All study animals had estradiol levels of less than 5.6 pg/ml at 6 mo after surgery. We therefore conclude that laparoscopic ovariectomy of rhesus macaques is a safe and effective technique that may reduce postoperative recovery times.