The NCP refers to the compression of the left renal
vein between the aorta and the superior mesenteric
artery.[
5] Nutcracker syndrome refers to the NCP
together with complicated symptoms.[
5] As there are
a limited number of experiential case reports and
case series on NCS, the definite incidence of the
syndrome remains unknown.
Since NCS is a rare disease, the diagnosis is
often delayed due to its non-specific diagnostic
criteria. Most patients, children, in particular, are
asymptomatic.[5] This pathology is more commonly
seen in young women. The disease can be clinically
silent or can give symptoms such as hematuria in 66%
of the patients, pelvic pain, flank pain, varicocele,
dysmenorrhea, and dysuria.[6] Hematuria which is
the most commonly seen symptom is attributed to
the rupture of thin-walled varices at the level of renal
calyces due to elevated venous pressures. Orthostatic
proteinuria which is defined as protein leakage from
calyceal system due to an elevated venous pressure
is seen in %0.6-10.7 of the Nutcracker cases and it
is a less common laboratory finding, compared to
hematuria.[7]
Color Doppler USG is an initially preferred noninvasive
method with a rough %78 sensitivity and
%100 specificity. Contrast CT, magnetic resonance
imaging, inferior vena cava manometry are used
in the first step to establish the final diagnosis,
retrograde flebografia, an invasive screening method,
follows these methods. Renocaval pressure gradient
less than 1 mmHg is classified as normal and
1-3 mmHg as borderline, while more than 3 mmHg
indicates potential NCS.[8]
Various treatment models such as observation,
conservative treatment and surgery are suggested in
adult patients. Different concepts and methods are
available for the treatment (Table 1). Conservative
approach is recommended in children due to spontaneous remissions. Medication including
medroxy progesteron acetate, goserelin acetate, and
antiinflammatory drugs is administered to the patients
with isolated pelvic congestion.[9] Severe hematuriarelated
anemia is the most common indication for
the treatment. Surgery or endovascular treatment
is recommended for the patients with tense flank
pain. Observation and conservative treatment are also
recommended for other patients with NCS.[7]
Table 1: Treatment strategies are divided into four groups
Anterior transposition of the left renal vein is a
prominent method for the patients with recurrent
hematuria attacks, massive proteinuria, severe flank
pain, and posterior NCS accompanied by elevated
renal vein pressures. Left renocaval bypass technique
is preferred due to low surgery complication risk and
maintained lower venous hypertension.[10]
Endovascular stent insertion requires long-term
anticoagulant prophylaxis. Potential stent complications
include obstruction caused by neointimal hyperplasia
development, embolization, and proximal migration of
the stent. Although stenting has effective short-term
results, long-term results remain unknown due to
inadequate data in the literature.
In conclusion, NCS which is a rare disease should
be kept in mind in the differential diagnosis among the patients with recurrent hematuria attacks and flank
pain. Although endovascular or laparoscopic stenting
appear to be an appealing option, open surgical repair
still remains reliable.
Declaration of conflicting interests
The authors declared no conflicts of interest with
respect to the authorship and/or publication of this
article.
Funding
The authors received no financial support for the
research and/or authorship of this article.
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