Novel type of atypical renal nutcracker syndrome accompanied by accessory left renal artery: a case report and literature review.

BACKGROUND

The renal nutcracker phenomenon is left renal vein entrapment that may cause hematuria, orthostatic proteinuria, left flank pain, and other extrarenal symptoms resulting from venous congestion. Most commonly, the renal vein is compressed between the anterior wall of the abdominal aorta and the superior mesenteric artery or between the posterior wall of the aorta and the vertebral column. Much less is known about uncommon entrapment mechanisms, which can lead to the same clinical presentation.

CASE REPORT: This case report presents a 78-year-old male with incidentally detected microhematuria caused by an atypical nutcracker phenomenon with two consecutive left renal vein stenoses: first between the left crus of the diaphragm and the portal vein, and second between the ureteropelvic junction and the splenic artery. A second vascular anomaly of the kidney, an accessory left renal artery, was also observed.

CONCLUSIONS

To the best of the authors' knowledge, this case report is the first to describe left renal vein entrapment between the right crus of the diaphragm and the portal vein. Understanding various uncommon mechanisms of the nutcracker phenomenon may be essential for diagnosing nutcracker syndrome without entrapment in typical locations.