Nutcracker syndrome is a rare cause of hematuria. Two children who presented to us with recurrent gross hematuria were evaluated. Renal parenchymal disease and abnormalities in the urinary tract were ruled out. CT angiography revealed a compressed left renal vein with dilatation and hence a diagnosis of nutcracker syndrome was made. A high index of suspicion is required for diagnosis of nutcracker syndrome.

1. Nutcracker syndrome in children presenting with recurrent
gross hematuria

2. Case Report
Nutcracker syndrome in children presenting with
recurrent gross hematuria
Alkarani T. Patil a,*
, K.S. Sanjay b
, M. Govindraj b
a
Associate professor of Pediatrics, Department of Pediatrics & Pediatric Nephrology, Indira Gandhi Institute of Child
Health, Bangalore, Karnataka, India
b
Department of Pediatrics, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
a r t i c l e i n f o
Article history:
Received 11 January 2015
Accepted 21 February 2015
Available online xxx
Keywords:
Nutcracker syndrome
CT angiography
Left renal vein
Superior mesenteric artery
Abdominal aorta
a b s t r a c t
Nutcracker syndrome is a rare cause of hematuria. Two children who presented to us with
recurrent gross hematuria were evaluated. Renal parenchymal disease and abnormalities
in the urinary tract were ruled out. CT angiography revealed a compressed left renal vein
with dilatation and hence a diagnosis of nutcracker syndrome was made. A high index of
suspicion is required for diagnosis of nutcracker syndrome.
Copyright © 2015, Indraprastha Medical Corporation Ltd. All rights reserved.
1. Introduction
The term of nut cracker syndrome (NCS) is used for patients
with clinical symptoms associated with nut cracker anatomy.
Nut cracker phenomenon (NCP) refers to compression of the
left renal vein (LRV), commonly between abdominal aorta (AA)
and superior mesenteric artery (SMA), leading to stenosis of
the aorto mesenteric portion of the LRV and dilatation of the
distal portion. The terms nut cracker phenomenon and nut
cracker syndrome are used as synonym in the literature. NCP
refers to anatomic and hemodynamic abnormalities, NCS re-
fers to clinical manifestations of the abnormality.1
This phe-
nomenon was first noticed in 1950 by El-Sadr and Mina2
and
later in 1972, the Belgian physician De Schepper3
referred to
the disorder as “nut cracker syndrome”. It is also called as LRV
entrapment syndrome and can be divided into two types.
Anterior NCS refers to compression of a normally situated LRV
by the aorta and the SMA and accounts for most of the NCS
cases. Posterior NCS, accompanied by a retroaortic LRV, is
usually attributed to a small space between the aorta and the
vertebral column.
Prevalence of NCS is unknown, though it may occur from
childhood to old age. Most symptomatic patients are in their
second and third decade of life, and is slightly more prevalent
in females.4
A low body mass index (BMI) has been shown to
correlate positively with NCS.5
Theories of causes of NCP
include posterior renal ptosis, an abnormally high course of
* Corresponding author. Incharge Pediatric Nephrology, Indira Gandhi Institute of Child Health, Dharmaram college post. Bangalore,
India.
E-mail address: alkaranipatilurs@gmail.com (A.T. Patil).
Available online at www.sciencedirect.com
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journal homepage: www.elsevier.com/locate/apme
a p o l l o m e d i c i n e x x x ( 2 0 1 5 ) 1 e3
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Please cite this article in press as: Patil AT, et al., Nutcracker syndrome in children presenting with recurrent gross hematuria,
Apollo Medicine (2015), http://dx.doi.org/10.1016/j.apme.2015.02.018

3. the LRV, and an abnormal SMA branching from the aorta.6
The
LRV compression leads to renal vein hypertension, leading to
rupture of the thin-walled vein into the renal calyceal fornix
with presentation of intermittent gross or microscopic he-
maturia. Collateral venous circulation formation such as
prominent left ovarian vein or testicular vein with its associ-
ated symptoms, such as vulvar varices in females or varico-
cele in males has been observed. Other symptoms include left
flank pain, orthostatic proteinuria, chronic fatigue syndrome
and gastrointestinal symptoms.7
Here we report two cases
with nut Cracker syndrome in our pediatric nephrology unit.
2. Case report
The first child was a 9 year old female child hospitalized in our
pediatric nephrology unit for intermittent hematuria and
recurrent left flank pain of 2 years duration. The patient
continued to have non colicky left flank and lower abdominal
pain, aggravated by change in position. The second child was 8
year old boy who came to our unit with similar complaints of
recurrent hematuria since 2 months, no significant past
medical history or examination findings were observed in
both the children. Urine red cell morphology showed
isomorphic red cells in both children. There was no evidence
of proteinuria in the early morning or day time urine sample
which was tested by dipstick method. 24 hrs urinary proteins
were 140 mg in the first child and 128 mg in the second child.
Urine calcium/creatinine ratio was 0.1 in both the children.
BMI was 14.34 kg/m2
and 12.62 kg/m2
respectively, which is
low in both the children. Renal ultrasonography and renal
doppler were found to be within normal limits. Computerized
tomography angiography (CTA) revealed acute angulation of
the origin of superior mesenteric artery from the aorta in both.
The angle between SMA and aorta was found to be less than 21
degrees in the first child (Fig. 1A) and 18 degrees in the second
child (Fig. 2A). The distal third of left renal vein was seen to be
significantly compressed between superior mesenteric artery
and aorta (Figs. 1B and 2B). These findings were characteristic
of nutcracker syndrome. The 9 year old female underwent
stenting of the left renal vein, and is on follow up with no
recurrence of hematuria. The second child received no surgi-
cal treatment and has remained stable over the subsequent
two years.
3. Discussion
NCS is rare but treatable condition.8
If a patient has symptoms
of hematuria and pelvic congestion,the association of left
sided flank pain, pelvic discomfort, pelvic and vulvar varices
in the female and varicocele in the male, constitutes a strong
basis for the diagnosis. Imaging, such as Doppler ultrasound,
computerized tomographic angiography (CTA), magnetic
resonance angiography (MRA) is required to diagnose NCS.
CTA and MRA can demonstrate the precise LRV compression
point together with peri renal and/or gonadal varices. Retro-
grade phlebography and cine video angiography with reno
caval pressure gradient determination is accepted as the gold
standard in the final diagnosis of NCS.8
The normal SMA
originates behind the neck of the pancreas at the level of the
first lumbar vertebra, and usually creates an acute angle at its
origin from the aorta. Mean SMA angles in children are
45.8 ± 18.2 degrees for boys and 45.3 ± 21.6 degrees for girls.
Mean SMA-aorta distances in children are 11.5 ± 5.3 mm for
boys and 11.5 ± 4.5 mm for girls.9
The angle between the aorta
and SMA in our report was found to be 21 and 18 degrees by
CTA. Both SMA angle and SMA distance correlate with BMI.
One of the presenting symptoms of NCS is weight loss and
most patients have low BMI at presentation.5
In both the
children BMI was low.
Conservative treatment has been suggested for mild he-
maturia. Surgical or radiological interventions are indicated
Fig. 1 e A: Coronal section of the CT- angiography shows
angulation between the abdominal aorta (AA) and superior
mesenteric artery (SMA) is < 21 degrees. B: Axial CT Image
showing compression of left renal vein between aorta and
superior mesenteric artery.
a p o l l o m e d i c i n e x x x ( 2 0 1 5 ) 1 e32
Please cite this article in press as: Patil AT, et al., Nutcracker syndrome in children presenting with recurrent gross hematuria,
Apollo Medicine (2015), http://dx.doi.org/10.1016/j.apme.2015.02.018

4. for severe pain, significant hematuria and renal functional
impairment or if symptoms are not relieved after more than
two years of conservative treatment. Current open surgery
technique includes LRV transposition, renal auto trans-
plantation, SMA transposition, gonadocaval bypass and
external stent implantation. LRV transposition is the most
frequent and most effective technique. The advantages are
shorter period of renal ischemia and fewer anastomosis,
although there is a risk of LRV thrombosis.10
Renal
autotransplantation is a more invasive technique with excel-
lent results. Placement of an external stent to the LRV is
another approach.1
Endovascular surgery (EVS) has defini-
tively become more appealing than traditional open surgery.8
Anticoagulant and antiplatelet treatment is recommended to
lower the risk of thrombosis.
In conclusion, any child presenting with intermittent he-
maturia not attributed to renal pathology or renal calculi
should be considered for a Doppler ultrasound and CTA to rule
out the presence of nut cracker syndrome. NCS can be
managed conservatively if mild hematuria is present. Surgical
or intravascular interventions are reserved for severe symp-
toms, and EVS is the primary treatment option for patients
requiring surgery.
Conflicts of interest
All authors have none to declare.
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Fig. 2 e A: Sagittal section of the CT- angiography shows
angulation between the abdominal aorta (AA) and superior
mesenteric artery (SMA) is < 18 degrees. B: Axial CT Image
showing compression of left renal vein between aorta and
superior mesenteric artery.
a p o l l o m e d i c i n e x x x ( 2 0 1 5 ) 1 e3 3
Please cite this article in press as: Patil AT, et al., Nutcracker syndrome in children presenting with recurrent gross hematuria,
Apollo Medicine (2015), http://dx.doi.org/10.1016/j.apme.2015.02.018

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