Bloody ballet

Clinical History

A 29-year-old presented with an acute onset of colicky left flank pain and frank haematuria. Physical examination was unremarkable apart from a left sided grade II varicocoele. His bloods were normal, apart from a white cell count of 12.5x109/L and 1000 RBC's on urinalysis.

Imaging Findings

The initial low-dose non-contrast CT shows asymmetry of renal size, with a larger left kidney. A collateral vascular network is seen surrounding the left kidney. The left renal vein (LRV) appeared pinched between the aorta and superior mesenteric artery (SMA). Post contrast-enhanced imaging clearly demonstrated the compression of the LRV and tortuous collateral veins surrounding the left kidney and its vascular pedicle.

Discussion

The diagnosis is Nutcracker Syndrome (NCS).

The term “Nutcracker” was first used as an anatomical description of the course of the LRV between the aorta and SMA by Grant (1937) [1].
It is more common in tall slender individuals, due to a perceived more acute aorto-mesenteric angle. The LRV receives venous tributaries from the left adrenal, left gonadal, ureteral and communicating second lumbar veins. If the valves in these veins are incompetent or absent, the LRV will remain normal, with no collateral formation. If the valves remain competent, the LRV pressure will be increased resulting in collateral formation.
The symptoms of NCS classically include loin pain and microscopic or frank haematuria. These symptoms are often positional, worse in the upright position, possibly due to a more pronounced visceral proptosis. Scrotal or vaginal varices as well as lower limb varices have an association with NCS, as do symptoms of fatigue and chronic fatigue syndrome. Pelvic congestion resulting form engorgement of pelvic venous collaterals may result in dyspareunia, dysmenorrhoea and dysuria in females, with symptoms increasing during pregnancy.
Diagnosis generally includes detailed history and physical examination with laboratory blood and urine tests. Cystoscopy may identify left sided unilateral haematuria. Doppler ultrasonography is a non-invasive method of assessing the LRV. However, no definitive criteria have been established for ultrasound diagnosis. Intravenous urogram and retrograde pyelogram are often normal although notching of the renal pelvis and ureters may be noticed indicative of a collateral venous network. CT can outrule other causes of haematuria and is also useful in delineating the anatomical relationship between the aorta, SMA and LRV and the presence and extent of venous collaterals. Recently 3-D CT angiography has been proposed as a useful tool in diagnosis and follow-up [2]. MR venography provides a radiation-free alternative.
Treatment may involve surveillance of the asymptomatic. Surgical procedures range from dividing a fibrous tunnel between the aorta and SMA to release the LRV [3]. Other procedures include LRV transposition, SMA transposition, renal auto-transplantation and gonado-caval bypass. More recently endovascularly deployed self-expanding stents have been used effectively avoiding the need for major surgery, however, the potential for serious complications such as stent thrombosis or stent migration should be considered.

Differential Diagnosis List

Final Diagnosis

Nutcracker syndrome as a rare cause of haematuria.

URL:	https://www.eurorad.org/case/9403
DOI:	10.1594/EURORAD/CASE.9403
ISSN:	1563-4086