Objective:

To describe a rare case of nontraumatic ureteral entrapment at the sacroiliac joint associated with degenerative changes and obstructive uropathy.

Approach:

• Case: A 77-year-old woman with chronic lower back pain and no urinary symptoms underwent evaluation after ultrasonography showed mild right hydronephrosis.
• Imaging: Contrast-enhanced CT intravenous pyelography showed hydroureter extending to the right sacroiliac joint, where the ureter was adherent and narrowed. The joint had advanced degenerative changes; no stone, mass, extrinsic compression, or surrounding fibrosis was…
• Management: The patient was managed conservatively with urologic surveillance and periodic renal ultrasonography. She declined a recommended renal functional scan.

Key Findings:

• CT findings indicated right ureteral entrapment at the sacroiliac joint, attributed to chronic degenerative sacroiliitis.
• Contrast excretion from the right kidney was markedly delayed, with persistent enhancement and mild cortical thinning.
• At 3 months, ultrasonography showed no significant progression of hydronephrosis.
• The authors described this as the third reported nontraumatic clinical case of ureteral entrapment at the sacroiliac joint.

Interpretation:

The authors stated that ureteral entrapment at a degenerative sacroiliac joint may be considered when hydronephrosis has no identified cause, and emphasized tracing the ureter across the joint on imaging.

Limitations:

• The report describes a single patient.
• A renal functional scan was not completed.
• Imaging follow-up was limited to 3 months, providing little evidence about long-term renal outcomes with conservative management.

Conclusion:

The patient’s obstruction was attributed to ureteral narrowing at the right sacroiliac joint rather than proximal ureteral kinking, which the authors considered a benign consequence of ureteral mobility.

Sources:

• Radiology Case Reports