nutcracker syndrome and its management

1. NUTCRACKER
SYNDROME
DR MANZOOR AHMAD
SKIMS UROLOGY

2. • Also k/a left renal vein entrapment syndrome.
• Entrapment of the left renal vein (LRV) between the
abdominal aorta and superior mesenteric artery (SMA)
plus the resulting clinical manifestations .
DEFINITION

3. VARIANTS
Superior Mesenteric Artery Syndrome (Wilkie syndrome)
Third portion of the duodenum courses in front of the LRV between the
aorta and the SMA
Posterior Nutcracker
The retroaortic or circumaortic renal vein compressed between the
aorta and the vertebral body,

4. • The true prevalence of Nutcracker
syndrome remains unknown.
• Thought to be higher in females.
• Most symptomatic patients are in their
second or third decade of life

5. ETIOLOGY
 Narrow aorto - mesenteric angle(AMA)
 Abnormally low or lateral origin of SMA
 Excessive fibrous tissue at the origin of
SMA
 Stretching of LRV over the aorta
 Abnormal posterior ptosis of the left
kidney
 Asthenic body habitus

6. PATHOPHYSIOLOGY
• Due to etiological factors
• Compression of the left renal vein
• Venous ruptures of the collecting system or
between dilated venous sinuses and
adjacent renal calyces
• Increased left renal vein pressure
• LRV hypertension
• Development of manifestations

7. CLINICAL MANIFESTATIONS
• Hematuria
• most commonly reported symptom
• attributed to rupture of thin-walled capillaries into
the collecting system
• Anemia from blood loss
• Varicose veins in the lower limbs.

8. • Pain ( left flank or pelvic pain)
• 2nd most common symptom
• As part of gonadal vein pain syndrome
• Left ureteral colic, from the passing of
blood clots down the left ureter.
CLINICAL MANIFESTATIONS

9. CLINICAL MANIFESTATIONS
• Varicoceles almost always occur on left
side.
• Since the left gonad drains via the left renal
vein it can also result in left testicular
varicocele
• Orthostatic proteinuria.
• Orthostatic intolerance.
• Nausea and vomiting can result due to

10. CLINICAL MANIFESTATIONS
• Positionality of symptoms is a hallmark of NCS
• Nutcracker phenomenon is more prominent in upright
and supine positions because of visceral proptosis and
changing aorto-mesenteric angle (AMA)

11. • Takebayashi et al have clinically differentiated NCS into
3 subtypes:
1. Idiopathic renal bleeding,
2. Massive orthostatic proteinuria (protein level >400
mg/dL), and
3. Severe orthostatic intolerance that markedly impairs
activities of daily living

12. DIAGNOSTIC EVALUATION
To rule out more common renal conditions,
diagnostic methods include
• Urinalysis, urine culture, cytology
• Blood investigations
• Urethrocystoscopy,
• CT urography, and
• Renal biopsy.

13. DIAGNOSTIC EVALUATION
Renal angiography
• shows delayed venous washout from the left kidney.
MRI and MR angiography/CT and CT angiography
• may demonstrate the compression of the left renal vein between
the superior mesenteric artery and the aorta.
IVU /RGP
• notching from varicosities of the renal pelvis and ureters may be seen
Multiphase CT urography
• demonstrate delayed nephrograms in patients with NCP/ NCS
• can clarify spatial relations between vessels
• almost always required before surgical interventions to exclude other
causes of pathologic findings.
Venography

14. USG
• Doppler ultrasound measurements of the anterior- posterior (A-P) diameter
and peak velocities of the left renal vein may be helpful in diagnosing
nutcracker syndrome
• First modality assessment after NCS is suspected clinically or when a large
LRV diameter ratio is noted between its distended and narrowed portions
(DD/N) on CT or MR imaging.
• A mirror image of the SMA in the aorta (extreme proximal parallel orientation)
has 50% sensitivity and 99% specificity for classical NCP.
• Peak ultrasound velocity ratios of the aorto-mesenteric (narrowed) (PVN) and
hilar (distended) (PVD) LRV portions with or without respective diameter
ratios have also been used with a sensitivity ranging from 69% to 90%, and
specificity from 89% to 100%.

16. MANGEMENT
Symptomatic treatment with observation
Analgesics
Anti emetics
Treating anemia
 For patients younger than 18 years, the best option is a
conservative approach with observation for at least 2 years
because as many as 75% of patients will have complete
resolution of hematuria.
 Angiotensin inhibitors may be helpful in improving orthostatic
proteinuria in patients with NCS.

17. SURGICAL MANAGEMENT
• Interventions should be considered only when
symptoms are severe or persistent, including
• severe unrelenting pain,
• severe hematuria,
• renal insufficiency, and
• failure to respond to conservative treatment after
24 months
• Most interventions aim to decrease LRV
hypertension, but others are directed against pelvic
venous reflux

18. • Left renal vein transposition
• Left renal vein bypass
• Superior mesenteric artery transposition
• Renal to IVC shunt
• Gonado-caval bypass
• Renal auto-transplantation
• Nephropexy
• Renal vein bypass grafting
• Nephrectomy
SURGICAL MANAGEMENT

19. COMPLICATIONS
Renal vein thrombosis
Deterioration of renl function

20. STENTING
• External stenting with ringed
polytetrafluoroethylene graft interposition around
the LRV
• Intravascular stenting.
• Long-term NCS follow-up
data are lacking.
• Anticoagulation is recommended till stent
endothelialization occurs (2-3 months).

21. OTHER TREATMENT OPTIONS
Collateral vein ligation
• may increase reno-caval pressure gradients and
should be combined with a procedure to relieve
renocaval pressure gradients.
Coil embolization
• of ovarian veins in patients with pelvic congestion
syndrome and demonstrable pelvic varicoceles
may provide symptomatic improvement in 56% to
98% of patients.

22. CONCLUSION
The Nutcracker syndrome is a rare condition,
but is certainly underdiagnosed. It should be
considered when patients present with left
flank pain and hematuria, or pelvic congestion
syndrome, or both.