19 The impact of obesity on native tissue repair outcomes: A secondary analysis of the OPTIMAL trial data

Abstract

The Operations and Pelvic Muscle Training in the Management of Apical Support Loss (OPTIMAL) trial was a multi-site, prospective randomized trial which compared sacrospinous ligament fixation (SSLF) and uterosacral ligament suspension (ULS) surgical outcomes, and also evaluated the impact of perioperative pelvic muscle training (PMT). Increasing body mass index (BMI) is associated with increased risk of pelvic organ prolapse and the prevalence of obesity is increasing worldwide. The purpose of this study is to better understand the impact of obesity on the results of native tissue vaginal apical suspension procedures. This study is a secondary analysis of data collected during the OPTIMAL trial, which is now a deidentified public dataset in the NIH Data and Specimen Hub database. Subgroup analysis of patients who received SSLF or ULS procedures and PMT or usual care was performed to determine if there were differences in surgical failure rates across a range of BMIs after two years. The sample size in this analysis was 297; not all of the original OPTIMAL data was available due to the deidentification process. Data were analyzed using ANOVA test, Tukey’s HSD post-hoc analysis, Fisher’s exact test, and Wald correct proportion risk difference test which is a method of identifying 95% confidence intervals. There were 75, 120, 63, and 39 patients in the normal, overweight, class 1 obesity, and class 2 obesity or greater BMI subgroups, respectively. The groups were not significantly different based on surgical arm or PMT arm, smoking, estrogen use, menopausal status, or number of cesarean sections (Table 1). However, there were differences in age, race, and number of vaginal births. In each BMI subgroup, the surgical failure rates and risk differences were not significantly different for the surgical or PMT arms (Table 2). Interestingly, the surgical failure rate increased in the ULS group with increasing BMI (normal = 30.56%, overweight = 30.16%, class 1 obese = 40.63%, class 2 obese or greater = 45%). Additionally, the risk difference between ULS and SSLF groups increased with BMI (normal = 5.34%, overweight = 8.44%, class 1 obesity = 1.92%, class 2 obesity or greater = 23.95%). The risk of surgical failure between ULS and SSLF, or PMT and usual care, is not significantly associated with increasing BMI. However, the increasing failure rate of ULS and difference in failure rates of ULS compared to SSLF with increasing BMI in our study may indicate an association if analyzed for a longer time period.View Large Image Figure ViewerDownload Hi-res image Download (PPT)