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

## TL;DR

This paper presents five rare cases where ureters were compressed by unusual blood vessels, leading to kidney issues and requiring specialized diagnosis and treatment.

## Contribution

The study highlights previously underreported vascular structures causing ureteric compression and emphasizes the importance of CT urography for diagnosis.

## Key findings

- Five rare cases of ureteric compression by unusual vascular structures were identified and treated.
- CT urography with multiple phases is crucial for diagnosing these rare vascular compression syndromes.
- Minimally invasive treatments like endoscopic ureterotomy effectively relieve the obstruction.

## Abstract

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.