Microbiome diversity predicts surgical success in patients with rectovaginal fistula.

INTRODUCTION AND HYPOTHESIS: Growing literature details the critical importance of the microbiome in the modulation of human health and disease including both the gastrointestinal and genitourinary systems. Rectovaginal fistulae (RVF) are notoriously difficult to manage, many requiring multiple attempts at repair before correction is achieved. RVF involves two distinct microbiome communities whose characteristics and potential interplay have not been previously characterized and may influence surgical success. METHODS: In this pilot study, rectal and vaginal samples were collected from 14 patients with RVF. Samples were collected preoperatively, immediately following surgery, 6-8 weeks postoperatively and at the time of any fistula recurrence. Amplification of the 16S rDNA V3-V5 gene region was done to identify microbiota. Data were summarized using both α-diversity to describe species richness and evenness and ß-diversity to characterize the shared variation between communities. Differential abundance analysis was performed to identify microbial taxa associated with recurrence. RESULTS: The rectal and vaginal microbiome in patients undergoing successful fistula repair was different than in those with recurrence (ß-diversity, p = 0.005 and 0.018, respectively) and was characterized by higher species diversity (α-diversity, p = 0.07 and p = 0.006, respectively). Thirty-one taxa were enriched in patients undergoing successful repair to include Bacteroidetes, Alistipes and Rikenellaceae as well as Firmicutes, Subdoligranulum, Ruminococcaceae UCG-010 and NK4A214 group. CONCLUSIONS: Microbiome characteristics associated with fistula recurrence have been identified. The association of higher vaginal diversity with a favorable outcome has not been previously described. Expansion of this pilot project is needed to confirm findings. Taxa associated with successful repair could be targeted for subsequent therapeutic intervention.

Characteristics of opioid users undergoing surgery for pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: Understanding demographic and opioid utilization patterns of preoperative opioid users compared with opioid-naïve patients undergoing surgical treatment for pelvic organ prolapse (POP) better informs opioid prescribing. METHODS: A cohort of preoperative opioid users undergoing surgery for POP from 1 January 2012 through 30 May 2017 was identified. Electronic medical records were utilized to obtain pain scores and prescription data. The cohort was organized by surgical approach, number of concomitant procedures, and patient age. These factors were then matched to pain scores, opioid quantity prescribed at discharge, and subsequent refills. Pain scores and opioid use were evaluated for correlation. Results were then compared with similar data previously published for opioid-naïve patients undergoing surgical treatment of POP. RESULTS: Preoperative opioid users were younger (55.5 [14.7] vs 59.5 [12.7]; p = 0.002), of higher body mass index (BMI; 29.2 [5.4] vs 28.6 [10.3]; p = 0.04), and less likely Caucasian (90.3% vs 95.9%; p = 0.002) than opioid-naïve patients. After matching for these differences, opioid users reported higher pain scores (3.5 [2.2] vs 2.6 [1.8]; p = <0.0001), but received similar opioid quantities (324.4 [395] vs 296 [158] oral morphine equivalents [OME]; p = 0.27; 16.8% vs 10.4% refill rates; p = 0.07). In preoperative opioid users, neither surgical approach nor the number of concomitant procedures influenced pain scores. Increasing mean pain scores (1.8 [2.0] to 4.2 [2.4]; p < 0.002) and OME prescribed (226 [170.2] to 541 [902.5] p = 0.056; 0% to 22.2% refill rates; p = 0.02), were seen with decreasing patient age. Pain scores correlated directly with the opioid amount prescribed. CONCLUSIONS: Patient age and preoperative opioid utilization should be factored into urogynecological postoperative opioid-prescribing protocols.