Chapter 165 - Nutcracker Syndrome Flashcards
Definition of nutcracker syndrome
AKA LRV entrapment syndrome, mesoaortic compression Left renal vein externally compressed by 1) SMA (anterior) 2) aorta and spine (posterior) in retroaortic LRV With symptoms
Definition of nutcracker phenomenon
LRV compression without symptoms
Symptoms of nutcracker syndrome
1) Hematuria (microscopic > gross) 2) left flank pain 3) pelvic compression with varicosities to leg, thigh, gluteal 4) varicocele in men (left side) 5) vulvar/labial varices in female 6) dyspareunia 7) dysmenorrhea 8) dysuria 9) proteinuria 10) abodominal pain 11) orthostatic proteinuria 12) chronic fatigue syndrome in children
Who first described nutcracker syndrome
Grant 1937
Who first clinically reported nutcracker syndrome
Mina + El-Sadr 1950
Who did first venography to demonstrated nutcracker syndrome
Chait 1970
Who first showed relationship between LRV compression and varicosities and hematuria
Shepper 1970
Who did the first transposition of LRV
Pastershank 1974
Nutcracker syndrome associated with these traits
1) female 2) young, with 2nd peak in 20-30s and 3rd peak middle age 3) low BMI 4) no clear ethnic relationship 5) non-hereditary
Other causes of LRV compression
1) pancreatic neoplasm 2) pancreatic lymphadenopathy 3) retroperitoneal tumours 4) overarching testicular artery 5) fibrolymphatic tissue/web between SMA and Ao 6) gravid uterus compression
Normal area between SMA and Ao
4-5 mm
LRV diameter normal
duplex 4-5 mm cadaver 1.2 +/- 0.2 cm
Causes of anterior Nutcracker syndrome
1) Acute angle of SMA take off < 16 2) posterior ptosis of left kidney 3) aberrant branch of SMA 4) cephalad course of LRV
Normal angle of SMA takeoff
35-40 degrees
Signs of anterior nutcracker syndrome
1) Dilated gonadal vein 2) pelvic collaterals
Posterior nutcracker syndrome prevalence
Prevalence of retroaortic LRV 0.77-3.18% Those symptomatic for NCS = 6.5%
Atypical variant for nutcracker syndrome
1) Circumaortic renal vein 2) left sided IVC 3) right sided NCS due to L IVC, L SVC, hemiazygous continuation
Skepticism that nutcracker syndrome exists because
1) NCP exist 2) LRV stretch in AAA are asymptomatic 3) LRV ligation in surgery usually inconsequential
Pathophysiology of microscopic bleed in nut cracker syndrome
1) LRV obstruction –> LRV hypertension –> RBC and protein leak into Glomerular filtrate 2) varices thin-walled ruptured into collection system
Duplex pro and con in nutcracker syndrome
Pro: 1) non-invasive 2) no radiation 3) readily available 4) shows flow and anatomy Con: 1) body habitus 2) bowel gas 3) interoperator variability Sensitivity 78 Specificity 100
Duplex criteria for nutcracker syndrome
Flow velocity at narrowed vs distended distal ratio > 5 Ratio of AP diameter between most dilated to most narrowed 1) > 3.7 in adults 2) > 4.3 in children
Axial imaging signs for nutcracker syndrome
1) Beak sign 2) retroaortic or circumaortic LRV 3) masses 4) collaterals 5) gonadal dilatation Sen 92%; spe 89% with beak sign alone Dx: 1) Angle < 41 degrees 2) LRV hilar aortomesenteric ratio > 4.9
Venography in nutcracker syndrome
Pull back pressure
Nishimura cutoff for nutcracker syndrome
> or = 3 mmHg for pull back pressure change
Takebayashi gradient for nutcracker syndrome
Normal < 1 mmHg Borderline hypertension 1-3 mmHg Hypertensive > or = 3
Cystoscopy in nutcracker
See blood from left renal but not useful for diagnosis
Management of Nutcracker in children
Conservative with growth and weight gain can widen aortomesenteric angle
Open treatment of anterior nutcracker syndrome
1) LRV transposition +/- patch 2) patch venoplasty 3) LRV transposition with GSV cuff 4) gonadal vein transposition 5) GSV bypass 6) gonadocaval bypass 7) resect fibrous tissue with placement of wedge at aortomesenteric angle 8) SMA transposition 9) left renal autotransplant 10) nephrectomy 11) external stent LRV 12) nephropexy
left renal vein transposition steps
1) midline laparatomy 2) cephalad and rightward retract small bowel 3) retroperitoneal entry 4) mobilize LRV 5) ligate gonad and adrenal 6) reimplant LRV to caudal IVC 7) +/- GSV patch for fibrotic distortion Syx resolution 87% 2 year patency 74%; freedom from reintervention 68%
Gonadal vein transposition steps
1) midline laparotomy 2) Kocherization and cephalad retraction of visceral 3) retroperitoneal entry
Key points in gonadal vein transposition
1) ensure it is large and long enough 2) useful to treat posterior NCS 3) avoids renal vein clamping and transection 4) avoids GSV harvest 5) single anastomosis
Who tried the first endo treatment of nutcrackers
Neste 1996
Risk of endo treatment for nutcracker
1) stent migration 2) stent fracture 3) stent thrombosis 4) protrusion into IVC but seems ok
Treatment algorithm for Nutcracker syndrome
