Ureteral endometriosis: a systematic review of epidemiology, pathogenesis, diagnosis, treatment, risk of malignant transformation and fertility

BACKGROUND: The ureter is the second most common site affected by urinary tract endometriosis, after the bladder. Optimal strategies in the diagnosis and treatment of ureteral endometriosis (UE) are not yet well defined. OBJECTIVE AND RATIONALE: The aim of this study was to systematically review evidence regarding the epidemiology, pathophysiology, diagnosis, medical and surgical treatment, impact on fertility and risk of malignant transformation of UE. SEARCH METHODS: A systematic literature review, by searching the MEDLINE and PUBMED database until April 2018, was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement and was registered in the PROSPERO registry (www.crd.york.ac.uk/PROSPERO CRD42017060065). A total of 67 articles were selected to be included in this review. OUTCOMES: The involvement of the ureter by endometriosis is often asymptomatic or leads to non-specific symptoms. When the diagnosis is delayed, UE may lead to persistent hydronephrosis and eventually loss of renal function. Ultrasonography is the first-line technique for the assessment of UE; alternatively, magnetic resonance imaging provides an evaluation of ureteral type involvement. The surgical treatment of UE aims to relieve ureteral obstruction and avoid disease recurrence. It includes conservative ureterolysis or radical approaches, such as ureterectomy with end-to-end anastomosis or ureteroneocystostomy performed in relation to the type of ureteral involvement. Fertility and pregnancy outcomes are in line with those observed after surgical treatment of deep infiltrating endometriosis (DIE). Current evidence does not support the potential risk of malignant transformation of UE. WIDER IMPLICATIONS: In this article, we review available evidence on ureteral endometriosis, providing a useful tool to guide physicians in the management of this disease. Diagnosis and management of UE remain a challenge. In relation to the degree of ureteral involvement and the association with other DIE implants, the surgical approach should be planned and carried out in an interdisciplinary collaboration between gynecologist and urologist.