28-year-old asian lady was referred by primary care doctor to renal clinic with concern of recurrent hematuria often associated with left flank pain

General

Heent

Neck

Cardiovascular

Lungs

Abdomen

Extremities

Skin

Neurological Exam

nutcracker-170503073014-1

Nutcracker phenomenon (NCP) or renal vein entrapment syndrome refers to compression of LRV between the abdominal aorta and proximal SMA-superiormesenteric artery causing interruption of blood flow from theLRV into the inferior vena cava (IVC). most likely etiology for this entrapment includes abnormal division of the left renal vein at ahigh level, a narrow mesoaortic angle, a pancreatic mass,lymph node enlargement, lack of retroperitoneal adiposetissue and abnormal branching of the SMA from theaorta. This pathology results in outflowblockage to the IVC secondary to LRV entrapment betweenAA and SMA causing LRV hypertension and varices andcollaterals formation in the nearby renal calyces.orthostatic proteinuria with or without flank pain ,Intermittent macroscopic or microscopic hematuria due to rupture of thin-walled septum between the varices and the collecting system in the renalfornix. Hematuria/proteinuria may be intermittent in nature due to the relative increase of venous hypertension, which mayworsen symptoms after periods of physical exertion orwhile in an upright position. Pathology of Orthostatic proteinuria is related to the increased liberation of angiotensinII and norepinephrine induced by changes in renalhemodynamic upon standing and increased LRV pressureand mild subclinical immune damage . The most common clinical symptoms such as hematuria, proteinuria, flank pain, abdominal pain, and varicocele. There are 2 variations of the syndrome.. A more common anterior NCS is created by the entrapmentof LRV between AA and SMA. There is common posterior NCS isEEG to the compression of retro-aortic LRVby abdominal aorta and vertebral column. NCS may show atypical presentation as abdominalpain, pelvic or scrotal discomfort due to varicocoele

Treatment decision should be based on the severity ofsymptoms, patient’s age, and the degree of LRV hypertension Conservative management and close observationis the best option for younger patients-less than 18 years old with intermittent hematuria, insignificant flank pain, and normal hemoglobin. Complete resolution of hematuria was noticed in 75% of young patients during a period of two years and this may be related to increasingbody mass index (BMI) during the developmental period. The phenomenon is more common in developing children relate to a relative paucity of retroperitoneal fat causing ‘bow-stringing’ of the LRV across the aortomesenteric angle due to more posterior position of the left kidney. Subsequent development resulting in increased height and body mass index serves to create a more favorable hemodynamic situation for the LRV and typically lead to symptom resolution.

Surgical intervention in NCS including: endovascularstenting, nephrectomy, nephropexy, reno-caval reimplantationor auto-transplantation, transposition of theLRV or SMA, and gonado-caval bypass] is indicatedin case of recurrent gross hematuria with anemia,severe flank pain, worsening of kidney function and failure of conservative management such as persistent orthostatic proteinuria after 24 months of follow-up