Correlation of Bladder Wall Endometriosis Histological Location, To Infertility Patients’ Clinical Characteristics and Severity of Peritoneal Endometriosis

Study question: What is the correlation of bladder wall endometriosis histological location, to the severity of peritoneal endometriosis in infertility patients? Summary answer: Secondary infertility, back pain, micturition problems, history of ectopic pregnancy and number of abortions can probably be considered as high-risk factors for bladder wall endometriosis for infertility patients. What is known already: Bladder and/or ureter endometriosis occur in 70–85% among patients with deep infiltrating endometriosis. The knowledge regarding the bladder wall involvement with endometriosis in association to peritoneal endometriosis and infertility patients’ clinical characteristics is limited. Study design, size, duration: Retrospective, longitudinal cohort, Sixty-six, primary and secondary infertility patients, collection of surgical and clinical data between 2010 to 2018. Participants/materials, setting, and methods: An experienced histopathologist on endometriosis was asked to review all the patients’ histopathological results. The histopathological reported findings were reviewed prior to the study to reassure the bladder wall depth of endometriosis involvement. The operation and tissue macroscopic description reports before processing were also reviewed. Attention was paid for possible discrepancies or missed important data that could influence the histopathological results. In cases where results were equivocal, the paraffin blocks were available for additional sections for reassuring the diagnosis. An extra effort was made to meticulously observe and identify the involvement of the bladder serosa, muscularis and mucosa with endometriotic cells and glands. Main results and the role of chance: Primary infertility was the indication for the current laparoscopic surgeries in 32 out of 66 (48.5%) patients and secondary infertility for the rest of the group. The highest incidence of bladder endometriosis (BE) was detected on the serosa of 12 patients and in the detrusor muscle (DM) of 11 cases. Bladder serosa endometriosis (BSE) was significantly more prominent among patients with history of ectopic pregnancy (p=0.004) and among patients with secondary infertility (p=0.029). Destrusor muscle endometriosis (DME) was significantly more frequent (p=0.012) in patients with increasing number of abortions. DME highest rates of 37.7% were observed among the severe spread of abdominal endometriosis as compared to 19% of the cases with bladder serosa endometriosis. No statistically significant difference found between serosa and detrusor muscle endometriosis involvement, when compared to severity and spread of endometriosis within the abdominal cavity. Back pain was most prominent with statistical significant difference (p=0.007) in 8 patients with BSE + DME as compared with other groups of patients (4 BSE, 3 DME and 3 BME+DME patients). Among 30 cases with an ovarian endometrioma detected by TVU, DME was diagnosed in 13 patients, in serosa of 10, and in serosa and DM of 6 patients. Statistical analysis was performed using Pearson chi-square, Fisher’s exact tests and the Kruskal-Wallis test by STATA version 15 SE (StataCorp. 2017). Limitations, reasons for caution: This is a cohort retrospective study. There is a possibility that other areas with endometriosis were also involved in the BW other than those diagnosed and treated. The mixture of patients with primary and secondary infertility could also affect the results, although statistical analysis did not show any significance in BWE, clinical symptoms and surgical findings. BE is rarely an isolated condition, and other forms of endometriosis are frequently concomitant Wider implications of the findings: Detrusor muscle endometriosis involvement was in 68% and bladder serosa in 32% of all cases with bladder endometriosis and infertility investigated. The severity of the peritoneal endometriosis can probably direct to meticulous intraoperative investigation for bladder endometriosis.