Duodenum

Question 1

First and shortest part of the small intestine

Widest and fixed part

C-shaped, about 10 inches long (25cm)

Begins at the pylorus on the right side and ends at the duodeno-jejunal junction on the left side (L2 vertebra)

Answer 1

DUODENUM

Question 2

Blood supply of duodenum

Answer 2

Upper part - SUPERIOR PANCREATICODUODENAL from gastroduodenal

Lower part- INFERIOR PANCREATICODUODENAL from superior mesenteric

Question 3

Venous drainage of duodenum

Answer 3

SUPERIOR PANCREATICODUODENAL vein drains into portal vein

INFERIOR PANCREATICODUODENAL joins the superior mesenteric vein

Question 4

Most often occur on the anterior wall of the first part of the duodenum followed by posterior wall

Answer 4

Duodenal ulcers

Question 5

Occur most often with ulcers on the anterior wall; less often with ulcers on the posterior wall (May erode the gastroduodenal artery causing severe hemorrhage and perforate into the pancreas)

Answer 5

Perforation of the duodenum

Question 6

25%

Male to female ratio = 1:1

Increase risk with blood type A

Bleeding from left gastric artery

Burning epigastric pain soon after eating; pain increases with food intake; relieved by antacids

LEFT GASTRIC ARTERY

Answer 6

Gastric ulcers

Question 7

75%

Male to female ratio = 2:1

Increased risk with blood type O

Bleeding from gastroduodenal artery; perforation

Burning epigastric pain 1-3 hours after eating; pain decreases with food intake; relieved with antacids; patient wakes at night because of pain

GASTRODUODENAL ARTERY

Answer 7

Duodenal ulcer

Question 8

The SUPERIOR MESENTERIC VESSELS may compress the horizontal part of the duodenum; patients experience EPIGASTRIC PAIN, NAUSEA after meal and bilious vomiting

Answer 8

Duodenal compression

Question 9

Parts of duodenum

Answer 9

Superior

• INTRAPERITONEAL, has a mesentery (thus mobile)
• begins at pylorus which is marked by prepyloric vein

Descending

• retroperitoneal
• receives CBD & main pancreatic duct on its posterior or medial wall at hepatopancreatic ampulla

Horizontal
- retroperitoneal, across L3 between SMA anteriorly, aorta & IVC posteriorly

Ascending
- Intraperitoneal, ascends to meet jejunum at duodenojejunal flexure, supported by ligament of Treitz (this ligament is the cranial end of dorsal mesentery)

Question 10

MC location: superior part of duodenum

Damage to mucosal barrier & acid hypersecretion due to H. Pylori (almost 100%)

Epigastric pain relieved by food

Tx: H2 blocker, PPI

Surgical procedure of choice: proximal gastric vagotomy which transects only the vagus nerve fibers to distal esophagus & gastric fundus

Answer 10

Duodenal ulcers

Question 11

Usually occurs with ulcers on anterior surface of duodenum

Posterior surface (less common) –> erode gastroduodenal artery –> severe hemorrhage

Answer 11

Duodenal perforations

Question 12

Divisions of duodenum

Answer 12

Superior (1st part) - 5cm & lies anterolateral to the body of L1

Descending (2nd part) - 7-10cm & descends along the right sides of L1 through L3

Horizontal (3rd part) - 6-8cm & crosses L3

Ascending (4th part) - 5cm & begins at the L of L3 and rises superiorly border of L2