Anatomy and aberrations

Question 1

Portal vein anomalies

Answer 1

Abnormalities include:

Agenesis (total/partial)

Abnormal branching

• Nakamara Classification
  
  • Type A = conventional
  • Type B = trifurcation
  • Type C = low take-off of right posterior
  • Type D = right anterior is branch of left
  • Type E = absent right anterior
  • Also: Absent left,Absent right

Preduodenal/prepancreatic

• Often associated with situs inversus
• Due to persistence of inferior communicating vein between vitelline veins

Double portal vein

Foetal valves

Question 2

Inferior vena cava

Answer 2

Develops from R & L anterior and posterior cardinal veins. Anterior and posterior fuse, left degenerates (remnant persists as left iliac)

Anomalies:
• Retrocaval ureter (due to persistent right posterior cardinal)
• Left sided IVC (persistent left supracardinal vein)
• Duplication of IVC (persistent bilateral supracardinal veins)
• Absent infrarenal IVC
• Circumaortic renal vein (venous collar)
• Retroaortic left renal vein
• Azygos continuation of IVC

Question 3

Hepatic arteries

Answer 3

1. Moynihan Hump - tortuous R hepatic in hepatocystic triangle

2. Michel Classification
  1 = normal (55%)
  2= replaced left (from left gastric)
  3 = replaced right (from SMA)
  4 = replaced left and right 
  5 = accessory left
  6 = accessory right
  7 = accessory left and right
  8 = one accessory, one replaced
  9 = CHA from SMA
  10 = CHA from left gastric

CHA can also come direct off abdominal aorta

Question 4

Superior laryngeal nerve

Answer 4

Cernea classification
Type 1 = >1cm from superior pole of thyroid
Type 2a = <1cm
Type 2b = at or below superior pole

Question 5

Cystic artery

Answer 5

Anomalous origin:

• Left hepatic
• Hepatic artery proper
• GDA
• Coeliac trunk
• Aorta

Crosses anterior to CHD

Double +/- any of above variations

Question 6

Biliary tree

Answer 6

Blumgart classification

• Type A: normal
• Type B: trifurcation
• Type C: RAS (C1) or RPS (C2) drains into CHD
• Type D: RPS (D1) or RAS (D2) drains into left
• Type E: Individual segmental branches
• Type F: RPS drains into cystic

Question 7

Recurrent laryngeal nerve aberrations

Answer 7

Non-recurrent right
- Associated with aberrant right subclavian artery arising from arch of aorta distal to left SCA (arteria lusoria) and running behind oesophagus

Non-recurrent left
- Associated with left sided aortic arch

Question 8

Cystic duct

Answer 8

A: low insertion
B: adherent to CBD
C: high insertion
D: drains into RHD
E: inserts behind duo
F: absent
G: spirals anterior to CBD
H: spirals posterior to CBD

Also:

• true cholecystohepatic duct - duct from GB straight into liver
• right posterior sectoral drains into GB/cystic duct

Question 9

Subclavian artery

Answer 9

AKA arteria lusoria
Aberrant right subclavian arises from arch of aorta distal to left SCA
Runs posterior to oesophagus and may cause dysphagia
Saccular aneurysmal dilation is called diverticulum of Komerrell

Question 10

Obturator artery

Answer 10

Aberrant obturator artery may form “Corona Mortis” - abnormal arterial ring caused by anastamoses between external iliac, inferior epigastric and obturator arteries

Runs posterior to pubic bones
Causes severe bleeding at laparoscopic hernia repair, or in pelvic fracture

Don’t miss these at angiography if patient unstable! Bleeding can be catastrophic.

Question 11

Blood supply of the breast

Answer 11

5 sources:

• 2nd perforator
• 3rd perforator
• Thoracoacromial
• Lateral thoracic
• Subscapular