Somatic and autonomic nerve density of the urethra, periurethral tissue, and anterior vaginal wall: an immunohistochemical study in adult female cadavers.

INTRODUCTION AND HYPOTHESIS: Retropubic procedures may disrupt nerves supplying the pelvic viscera; however, knowledge of pelvic neuroanatomy is limited. We sought to characterize somatic and autonomic nerve density within the urethra, periurethral tissue, and anterior vagina. METHODS: Axial sections were obtained from pelvic tissue harvested from female cadavers ≤24 h from death at three anatomical levels: the midurethra, proximal urethra, and upper trigone. Periurethral/perivesical tissue was divided into medial and lateral sections, and the anterior vagina into middle, medial, and lateral sections. Double immunofluorescent staining for beta III tubulin (ßIIIT), a global axonal marker, and myelin basic protein (MBP), a myelinated nerve marker, was performed. Threshold-based automatic image segmentation distinguished stained areas. Autonomic and somatic density were calculated as percentage of tissue stained with ßIIIT alone, and with ßIIIT and MBP respectively. Statistical comparisons were made using nonparametric Friedman tests. RESULTS: Six cadavers, aged 22-73, were examined. Overall, autonomic nerve density was highest at the midurethral level in the lateral and middle anterior vagina. Somatic density was highest in the external urethral sphincter (midurethra mean 0.15%, SD ±0.11; proximal urethra 0.19%, SD ±0.19). Comparison of annotated sections revealed significant differences in autonomic density among the lateral, medial, and middle vagina at the midurethra level (0.71%, SD ±0.48 vs 0.60%, SD ±0.48 vs 0.70%, SD ±0.63, p=0.03). Autonomic density was greater than somatic density in all sections. CONCLUSIONS: Autonomic and somatic nerves are diffusely distributed throughout the periurethral tissue and anterior vagina, with few significant differences in nerve density among sections analyzed. Minimizing tissue disruption near urethral skeletal muscle critical for urinary continence may prevent adverse postoperative urinary symptoms.

Incidence of Sacral Osteomyelitis and Discitis After Minimally Invasive Sacrocolpopexy.

OBJECTIVE: The incidence and associated risk factors for sacral osteomyelitis and sacral discitis after sacrocolpopexy remain unknown. The aim of this study was to determine the incidence of sacral osteomyelitis and discitis after minimally invasive sacrocolpopexy and their association with the method of sacral mesh fixation. METHODS: This is a retrospective cohort study of consecutive minimally invasive sacrocolpopexies performed by 11 female pelvic medicine and reconstructive surgery board-certified surgeons from January 2009 to August 2019 within a single health system. Sociodemographic, procedure, and clinical variables were abstracted from the electronic health record (EHR). We then performed a confirmatory EHR interrogation, cross-referencing procedural codes for laparoscopic and robot-assisted sacrocolpopexy and diagnostic codes for sacral osteomyelitis and sacral discitis. RESULTS: The EHR chart review identified 1,189 women who underwent laparoscopic (55.2%) and robot-assisted (44.8%) minimally invasive sacrocolpopexy, all with polypropylene mesh. Median follow-up was 7.7 months (interquartile range, 0-49.8). Titanium helical tacks were used in 52.7% patients, sutures in 41.6%, and both in 5.6%. No cases (0%) of sacral osteomyelitis or discitis were identified by chart review. The system-wide EHR interrogation of procedural and diagnostic codes identified 421 additional procedures for a total of 1,610 minimally invasive sacrocolpopexies. Among these, there were no cases (0%) of osteomyelitis or discitis. CONCLUSIONS: Sacral osteomyelitis and discitis are rare early outcomes after minimally invasive sacrocolpopexy with an incidence of less than 1/1,000 cases. Given an absence of cases, we were unable to assess for an association between method of sacral attachment and sacral osteomyelitis and sacral discitis.