1 - Abdominal Vasculature and Lymphatics

Question 1

Objectives: Understand the developmental basis of arterial supply to abdomen

Major Vessels + Region

Answer 1

• Major Vessels:
  
  • Celiac Trunk - Foregut - T12
  • Superior Mesenteric - Midgut - L1
  • Inferior Mesenteric - Hindgut - L3

Question 2

Objectives: Explain branching and distribution of abdominal arteries and areas of anastomoses

Celiac Trunk

Superior Mesenteric

Inferior Mesenteric Artery

Answer 2

• Celiac Trunk: Major Branches (many minor)
  
  • Left Gastric
  • Splenic
  • Common Hepatic
• Superior Mesenteric: Major Branches
  
  • Inferior Pancreaticoduodenal - Inferior Pancrease / Duodenum
  • Intestinal Branches (many) - Jejunum / Ileum
  • Middle Colic - Transverse Colon
  • Right Colic - Ascending Colon
  • Ileocolic - Cecum
• Inferior Mesenteric: Major Branches
  
  • Left Colic - Descending Colon
  • Sigmoid Branches
  • Superior Rectal

Question 3

Objectives: Explain branching and distribution of abdominal arteries and areas of anastomoses

Arterial Anastomoses (2x)

Clinical?

Answer 3

• Celiac and Superior Mesenteric Arteries
  
  • Around head of pancreas via Superior and Inferior Pancreaticoduodenal Arteries
• Superior and Inferior Mesenteric Arteries
  
  • Near Left Colic Flexure through Marginal Artery (of Drummond) all along colon
• Clinical:
  
  • If main vessel becomes blocked, one of other arteries may increase in caliber over time to compensate for blood supply

Question 4

Objectives: Understand anatomy and function of portal and caval venous drainage systems

Portal System

Caval System

Answer 4

• Portal System: Drains digestive organs into Portal Vein
  
  • ​Portal Vein formed by junction of Splenic + Superior Mesenteric Veins
    
    • ​Inferior Mesenteric joins one of these (variable)
  • NO VALVES, drain to Liver
• Caval System: Drains non-digestive structures into Inferior Vena Cava
  
  • ​Legs, Body Wall, Urogenital, Reproductive drain direct to IVC
  • Includes Azygous/Hemiazygous
  • L/R Renal
  • Lumbar Veins
  • Common (Ext + Int) Iliac

Question 5

Objectives: Explain the main tributaries of portal and caval systems

Answer 5

• Portal:
  
  • L/R Gastric
  • Splenic
  • Superior / Inferior Mesenteric
  • Superior Rectal
• Caval:
  
  • Azygous / Hemiazygous
  • L/R Renal
  • Lumbar
  • Common (Ext + Int) Iliac

Question 6

Objectives: What are the four areas of portal-caval anastomoses and what are their clinical symptoms?

Answer 6

• Clinical: Anything obstructing Portal system can cause portal hypertension (mass, obstruction) due to lack of valves.
  
  • Blood will backflow, and produce varicose veins in these areas
• Area - Portal - Caval - Symptom:
• Esophagus - L. Gastric - Esophageal - Esophageal Varices
• Umbilicus - Paraumbilical - Superficial Epigastric - Caput Medusae
• Rectum - Superior Rectal - Inferior Rectal - Internal Hemorrhoids
• Post. Abdominal Wall - Colic Veins - Retroperitoneal Veins - Asymptomatic

Question 7

Objectives: Explain the pathway of lymphatic drainage in the abdomen

Areas of concern? Why?

Answer 7

• Lymph flow in abdomen follows path of blood vessels
• Clinically significant when close structures receive different blood supplies–can have spreading of disease (cancer)
• Main Areas of Concern:
  
  • ​Testes + Scrotum
  • Superior + Inferior Half of Anal Canal

Question 8

Objectives: Explain the pathway of lymphatic drainage in the abdomen

Regional Drainage:

Abdominal Wall

Inguinal Region

GI Tract (not anal canal, own card)

Posterior Abdomen, Kidneys, Suprarenal Glands

Answer 8

• Abdominal Wall:
  
  • Superior to Umbilicus
    
    • Anterior / Posterior Axillary Nodes
  • Inferior to Umbilicus
    
    • Superficial Inguinal Nodes
• Inguinal Region:
  
  • Testis
    
    • Para-aortic (lumbar) nodes
  • Scrotum / Skin of Labia Majora
    
    • Superficial Inguinal nodes
• Gastrointestinal Tract: Drain into pre-aortic nodes (3x below); form intestinal trunk, drains into Cisterna Chyli
  
  • Celiac Nodes
  • Superior Mesenteric Nodes
  • Inferior Mesenteric Nodes
• Post. Abd., Kidneys, Supr. Renal Glands:
  
  • Posterior Abdomen - Pre-aortic / Para-aortic (lumbar) nodes
    
    • Pre/Para Nodes join to form Cisterna Chyli, start of Thoracic Duct

Question 9

What is the lymph drainage pattern of the anal canal?

Answer 9

• Superior to Pectinate Line:
  
  • Blood from Inferior Mesenteric
  • Inferior Mesenteric Nodes
• Inferior to Pectinate Line:
  
  • Blood from branches of Internal Iliac
  • Superficial Inguinal Nodes