Ureter as an Innocent Bystander: Presentation and Management in Unusual Vascular Compression Syndromes.

Objective Abdominopelvic vascular compression syndromes occur when the vascular structures either cause compression or are compressed by the surrounding hollow viscera. Apart from retrocaval ureter and UPJO (ureteropelvic junction obstruction), ureteric compression by other vascular structures is rare. We present five rare cases of ureter compression caused by the inferior mesenteric vein, testicular vein, ovarian vein, common iliac arteries, and an unnamed tributary of the inferior vena cava (IVC). Methods Retrospective data of all cases of hydroureteronephrosis between January 2019 and March 2020 were studied. Out of the 659 cases identified, the search was narrowed to keywords like "vascular compression", "ureteric compression", and "crossing vessels". A total of 11 cases were identified. Excluding six cases of UPJO, we were left with five cases of extrinsic ureteric compression caused by other vascular structures. Results Case 1 was a 26-year-old man with ureteric compression by the inferior mesenteric vein. Case 2 was a 27-year-old man with an incidental intraoperative finding of the left testicular vein compressing the upper ureter. Case 3 was a 38-year-old female with a dilated upper ureter due to compression by the right ovarian vein. Case 4 was a 19-year-old female with compression of bilateral mid-ureters by common iliac arteries. Case 5 was a 26-year-old man with an upper ureteric stricture due to a crossing tributary of the IVC. Conclusion Vascular compression of the ureter, by ovarian or testicular veins, common iliac arteries or veins, or unusual IVC tributaries, though rare, can cause proximal hydroureteronephrosis, stones, and pyelonephritis. CT urography, which includes arterial, venous, and excretory phases, is essential for accurate diagnosis. Management of such syndromes includes retrograde pyelography +/- temporary stenting and definitive minimally invasive measures like endoscopic ureterotomy, ureterolysis, and/or definitive reconstruction, effectively relieving obstruction and preventing complications.