Posterior Nutcracker Syndrome with Left Renal Vein Duplication: A Rare Cause of Haematuria in a 12-Year-Old Boy

The nutcracker syndrome (NCS) is a rare cause of haematuria. It embraces an extended nonpathognomonic spectrum of symptoms that imply a difficult diagnosis. Ultimately it may be associated with substantial morbidity and even life-threatening events. We report a rare cause if a 12-year-old boy who presented with a history of frequent intermittent episodes of painless constant haematuria. The cystoscopy showed a bloody urine ejaculate from the left ureter meatus. The Doppler ultrasonography showed turbulent pattern of venous blood flow of the posterior renal vein branch behind the aorta. The abdominopelvic computer tomography (apCT) revealed left renal vein (LRV) duplication with a dilated retroaortic branch, entrapped between the aorta and the vertebral column, promoting the renal nutcracker syndrome. The patient was initially hospitalized and managed with oral iron supplements and continuous saline bladder irrigation, not requiring additional treatment. The child is currently asymptomatic, with haemoglobin value returning to normal and therefore proposed to conservative management with close followup. The authors present a case report of episodic haematuria caused by a rare entity—posterior nutcracker syndrome with renal vein duplication. 1. Introduction Nutcracker syndrome is a rare cause of haematuria caused by the left renal vein (LRV) entrapment [1–5], most usually between the aorta and the superior mesenteric artery (SMA), known as anterior nutcracker syndrome. Sometimes a retroaortic position of the LRV also promotes an entrapment, this time between the aorta and the vertebral column, which is named posterior nutcracker syndrome [6]. Although the first clinical report was made by El-Sadr and Mina [1] in 1950, the term nutcracker is credited to de Schepper in 1972 [2] but was first used by Chait et al. in 1971 [3]. This term must be distinguished from the Nutcracker Phenomenon [4]. This is a relatively common anatomical variance, in which the patient stays asymptomatic, and it is often diagnosed in an occasional imaging exam. It usually affects women more than men [1] and in most cases present in the 3rd or 4th decades of life. When symptomatic this syndrome is manifested by left flank and abdominal pain, with or without unilateral macroscopic or microscopic haematuria. When the venous reflux caused by the LRV entrapment leads to the formation of collaterals this syndrome may be a cause of “pelvic congestion syndrome” characterized by an array of signs and symptoms such as dyspareunia, dysmenorrhoea, lower abdominal pain and pelvic, perineal and