Ureteric obstruction secondary to endometriosis

EDITOR,-R J Brough and K O'Flynn report a case of bilateral ureteric obstruction secondary to recurrent endometriosis in a patient receiving hormone replacement therapy.' This is a rare complication; even the 1.2% rate of ureteric obstruction that the authors quote is probably an overestimate, as a Medline search for 1966-96 shows fewer than 200 reported cases worldwide, with the largest modern series being just eight cases from the combined records of two large teaching hospitals.2 Ureteric obstruction can result in irretrievable renal loss, and early recognition is vital, as Brough and O'Flynn emphasise. Nevertheless, we believe that the authors' suggestion that "routine imaging, either intravenous urography or preferably isotope renography," should be used to assess any patient with endometriosis" is misleading; more importantly, we believe that this would be unsafe practice as it would expose women, many of whom will be of reproductive age, to harmful irradiation. Ultrasonography is a more appropriate investigation in assessing renal obstruction because it is sensitive in chronic obstruction, relatively inexpensive, and safe. Ultrasonography will not identify nonobstructive ureteric endometriosis, but neither does urography lead to a confident diagnosis of ureteric involvement.3 This is not to say that we advocate routine use of ultrasonography in all patients with endometriosis. Our view is that patients with loin pain, as in this case, merit renal assessment by ultrasonography. In women with a history of endometriosis (particularly ifthey have recently started hormone replacement therapy) or with a cyclical history of pain or haematuria, endometriosis should be suspected, looked for, and excluded.