nutcracker phenomenon

nutcracker syndrome

nonglomerular hematuria due to compression of the left renal vein between the aorta and superior mesenteric artery; renal hilar varices, collateral veins, and proteinuria may be found. See: nutcracker. Synonym(s): nutcracker phenomenon
A rare clinical complex which occurs in relatively young and previously healthy people, which is characterised by compression of the left renal vein (LRV) between the aorta and superior mesenteric artery (SMA), fancifully likened to the effect of a nutcracker, with the aorta and SMA each corresponding to an arm of the nutcracker and the LRV to the nut itself. The squeezing can lead to left renal vein hypertension, resulting in rupture of the thin walled vein into the renal calyceal fornix
Diagnosis Left renal venography—gold standard test, CT, abdominal ultrasonography
DiffDx Kidney stones, genitourinary malignancy, loin pain haematuria syndrome
Management Nephrectomy, nephropexy, renocaval reimplantation, auto-transplantation, left renal vein transposition, stenting, gonadal vein embolisation

nutcracker phenomenon

Nutcracker syndrome A clinical finding in Hb SC disease, in which left-sided renal hemorrhage causes infarction of renal papillae, due to ↑ pressure as the left renal vein passes between the aorta and the superior mesenteric artery; ↑ pressure causes renal medullary hypoxia sufficient to sickle the RBCs