Nontraumatic unilateral ureteral entrapment at the sacroiliac joint: A rare cause of obstructive uropathy

Ureteral entrapment within the sacroiliac joint is an exceedingly rare anatomical phenomenon. To date, 6 cases have been documented in the literature: 1 cadaveric and 5 clinical reports. Among the clinical cases, 3 followed high-energy pelvic trauma, while 2 were nontraumatic. We report the third nontraumatic clinical case (and seventh case overall) in a 77-year-old woman presenting with chronic lower back pain. Computed tomography intravenous pyelography revealed focal entrapment of the right ureter at the level of the sacroiliac joint due to advanced degenerative sacroiliitis. Despite a 10-12 hours delay in contrast excretion, the patient was urologically asymptomatic with stable renal function. Unlike previous nontraumatic cases requiring surgical intervention or nephrostomy, this patient was managed conservatively.