Chapter 165 - Nutcracker Syndrome

Question 1

Definition of nutcracker syndrome

Answer 1

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

Question 2

Definition of nutcracker phenomenon

Answer 2

LRV compression without symptoms

Question 3

Symptoms of nutcracker syndrome

Answer 3

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

Question 4

Who first described nutcracker syndrome

Answer 4

Grant 1937

Question 5

Who first clinically reported nutcracker syndrome

Answer 5

Mina + El-Sadr 1950

Question 6

Who did first venography to demonstrated nutcracker syndrome

Answer 6

Chait 1970

Question 7

Who first showed relationship between LRV compression and varicosities and hematuria

Answer 7

Shepper 1970

Question 8

Who did the first transposition of LRV

Answer 8

Pastershank 1974

Question 9

Nutcracker syndrome associated with these traits

Answer 9

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

Question 10

Other causes of LRV compression

Answer 10

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

Question 11

Normal area between SMA and Ao

Answer 11

4-5 mm

Question 12

LRV diameter normal

Answer 12

duplex 4-5 mm cadaver 1.2 +/- 0.2 cm

Question 13

Causes of anterior Nutcracker syndrome

Answer 13

1) Acute angle of SMA take off < 16 2) posterior ptosis of left kidney 3) aberrant branch of SMA 4) cephalad course of LRV

Question 14

Normal angle of SMA takeoff

Answer 14

35-40 degrees

Question 15

Signs of anterior nutcracker syndrome

Answer 15

1) Dilated gonadal vein 2) pelvic collaterals

Question 16

Posterior nutcracker syndrome prevalence

Answer 16

Prevalence of retroaortic LRV 0.77-3.18% Those symptomatic for NCS = 6.5%

Question 17

Atypical variant for nutcracker syndrome

Answer 17

1) Circumaortic renal vein 2) left sided IVC 3) right sided NCS due to L IVC, L SVC, hemiazygous continuation

Question 18

Skepticism that nutcracker syndrome exists because

Answer 18

1) NCP exist 2) LRV stretch in AAA are asymptomatic 3) LRV ligation in surgery usually inconsequential

Question 19

Pathophysiology of microscopic bleed in nut cracker syndrome

Answer 19

1) LRV obstruction –> LRV hypertension –> RBC and protein leak into Glomerular filtrate 2) varices thin-walled ruptured into collection system

Question 20

Duplex pro and con in nutcracker syndrome

Answer 20

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

Question 21

Duplex criteria for nutcracker syndrome

Answer 21

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

Question 22

Axial imaging signs for nutcracker syndrome

Answer 22

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

Question 23

Venography in nutcracker syndrome

Answer 23

Pull back pressure

Question 24

Nishimura cutoff for nutcracker syndrome

Answer 24

> or = 3 mmHg for pull back pressure change

Question 25

Takebayashi gradient for nutcracker syndrome

Answer 25

Normal < 1 mmHg Borderline hypertension 1-3 mmHg Hypertensive > or = 3

Question 26

Cystoscopy in nutcracker

Answer 26

See blood from left renal but not useful for diagnosis

Question 27

Management of Nutcracker in children

Answer 27

Conservative with growth and weight gain can widen aortomesenteric angle

Question 28

Open treatment of anterior nutcracker syndrome

Answer 28

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

Question 29

left renal vein transposition steps

Answer 29

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%

Question 30

Gonadal vein transposition steps

Answer 30

1) midline laparotomy 2) Kocherization and cephalad retraction of visceral 3) retroperitoneal entry

Question 31

Key points in gonadal vein transposition

Answer 31

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

Question 32

Who tried the first endo treatment of nutcrackers

Answer 32

Neste 1996

Question 33

Risk of endo treatment for nutcracker

Answer 33

1) stent migration 2) stent fracture 3) stent thrombosis 4) protrusion into IVC but seems ok

Question 34

Treatment algorithm for Nutcracker syndrome

Answer 34