Should a detailed ultrasound examination of the complete urinary tract be routinely performed in women with suspected pelvic endometriosis?

STUDY QUESTION: Is there any benefit to including the routine examination by ultrasound of the bladder, ureters and kidneys of women with endometriosis?

SUMMARY ANSWER: The benefit of examination of the complete urinary tract of women with suspected endometriosis is that ureteric endometriosis, with or without hydronephrosis, can be detected which facilitates early intervention to prevent nephropathy.

WHAT IS ALREADY KNOWN: Women with endometriosis can get ureteric obstruction but there is no clear consensus on the correct diagnostic technique. Ultrasound is accurate at detecting women with bladder endometriosis but ureteric involvement has not been assessed previously.

STUDY DESIGN, SIZE, DURATION: This was a prospective observational study, conducted at a teaching hospital over a period of 14 months. A total of 848 women presenting with chronic pelvic pain were included into the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS: All women with chronic pelvic pain underwent a detailed transvaginal and transabdominal pelvic ultrasound examination to investigate possible causes of their symptoms. This included a systematic assessment of the urinary bladder, pelvic sections of the ureters and kidneys. The ultrasound findings were compared with findings at surgery and the results of targeted urological imaging and interventions.

MAIN RESULTS AND THE ROLE OF CHANCE: A total of 848 women presenting with chronic pelvic pain were included into the study. 28/848 women (3.3% 95% CI 2.1-4.5) had evidence of urinary tract abnormalities on initial ultrasound scan. Among these 17/848 (2.0% 95% CI 1.06-2.94) had evidence of urinary tract endometriosis, whilst 11/848 (1.3% 95% CI 0.54-2.06) women had other urinary tract abnormalities. Among women with urinary tract endometriosis 11/17 (65%) had evidence of ureteric involvement, 3/17 (18%) had both ureteric and bladder disease and 3/17 (18%) had bladder disease only. 12/17 (59%) women with urinary tract endometriosis also had evidence of hydronephrosis. The diagnosis of ureteral endometriosis had a sensitivity of 12/13 (92%) (95% CI 63.9-99.8), specificity 151/151 100% (95% CI 97.6-100), PPV 100% (95% CI 73.5-100), NPV 99.3% (95% CI 96.3-99.9%) LR- 0.08 (95% CI 0.01-0.39).

LIMITATIONS, REASONS FOR CAUTION: The routine examination of the complete urinary tract including the distal ureters is a novel technique that should be evaluated in different populations.

WIDER IMPLICATIONS OF THE FINDINGS: Ultrasound is an accurate test to diagnose urinary tract involvement in women with suspected pelvic endometriosis and examination of the complete urinary tract should become an integral part of ultrasound assessment of women with suspected endometriosis.