The research, “Deep Infiltrating Endometriosis – Urinary Tract Involvement and Predictive Factors for Major Surgery,” appeared in the journal Urology.
Deep infiltrating endometriosis is the most aggressive clinical form of the condition. Severity of symptoms is associated with the depth of infiltration. The most affected organs are the bladder (approximately 84%) and the ureter (10%), whereas the urinary tract is only affected in 1-5%of all women with endometriosis.
The diagnosis of urinary tract endometriosis (UTE) is challenging. Approximately 50% of patients are asymptomatic. When present, symptoms are often nonspecific, which may lead to substantial delays in diagnosis. This delay could be particularly serious in patients with ureter involvement due to the risk of hydronephrosis (kidney swelling caused by urine build-up) and loss of renal function.
Pelvic examination is required when UTE is suspected, with conclusive diagnosis based on exploration (typically with surgery, by laparoscopy) and histopathological (tissue) evaluation. The preferred treatment for UTE is surgical removal of endometriotic lesions. Surgery is performed when symptoms are observed or hydronephrosis occurs.
Conversely, partial cystectomy (removal of the bladder) is the most effective approach in bladder endometriosis. Regarding patients with ureteral endometriosis, the type of intervention depends on the location of lesions.
The research was led by Maria Jose Freire, from the Department of Urology and Renal Transplantation, Coimbra Hospital and University Centre, in Portugal. The scientists determined the urinary tract involvement in deep infiltrating endometriosis, the existing surgical treatment and the potential predictive factors for major urologic surgery.
The study analyzed 656 women who underwent surgery for endometriosis. Twenty-eight patients had minor or major surgery for deep infiltrating endometriosis involving the urinary tract. Mean age at diagnosis was approximately 38 years.
Minor surgery consisted of endoscopic surgery or percutaneous nephrostomy (a procedure to decompress the renal collecting system), whereas major surgery included open or laparoscopic procedures.
Prevalence of UTE in patients who had surgery was 4.3%, matching previous studies. However, ureteral involvement was higher (17/656, 2.6%) than earlier reports (0.1-0.4%), which may be derived from higher incidence in deep infiltrating endometriosis and “growing experience and awareness of physicians and the greater use of laparoscopic techniques,” the authors wrote.
The researchers observed that, contrary to the literature, the ureter was more often affected (60.7%) than the bladder (53.6%). This may be due to more prompt response of physicians in the former due to risk of renal function loss, and unspecific symptoms in the latter, causing delays in diagnosis.
Results from the subgroup with surgery for deep infiltrating endometriosis revealed that endometriomas (cysts) were observed in the ureter in 14 (46.4%) patients. Bladder involvement was observed in 11 (39.3%) and ureter+bladder endometriomas happened in four (14.3%) patients. Diminished renal function occurred in 12 (42.9%) patients.
Minor surgeries were performed in most women with isolated bladder involvement and in 12 (42.9%) patients with ureteral infiltration. Patients with ureteric involvement underwent major surgeries more often and had longer hospitalization (8.2 vs 3.1 days). After a mean follow-up of 36.3 months, there was no recurrence of bladder involvement. The most common complication was ureteral stenosis (narrowing) in three (10.7%) patients.
Overall, the study shows that surgery is highly successful in most cases. Furthermore, “patients with ureteric involvement were more likely to lose kidney function, undergo major surgery and to have longer hospitalization,” the authors concluded.