3. DUODENUM
25cm
C shaped loop
lies opp to L1,2,3
duodenum begins at the duodenal
bulb and ends at the ligament of Treitz,
It is composed of four distinct parts .
4. 4parts
1st/superior-
5cm, begins at pylorus and passes
backwards,upwards and to the right
2nd /desending-
8cm,passes downwards(slight convexity to
the right), it has major and minor duodenal
papilla
3rd /horizontal-
10cm, passes from right to left
4th/ascending-
2cm, upwards and to the left
5. D1
• It is intraperitoneal for the first 2-3 cm
only.
The ligament of Treitz, also known as the suspensory
ligament of the duodenum, is a double fold of peritoneum
suspending the duodenojejunal flexure from
the retroperitoneum.
6. CLINICAL
1. The ligament of Treitz represents an anatomic landmark, particularly during endoscopic
procedures, for differentiating between the sources of upper gastrointestinal bleeding
(i.e., originating proximal to the ligament) and lower gastrointestinal bleeding (i.e.,
originating distal to the ligament)
2. An abnormal increase in the length of the ligament can cause intestinal malrotation.
7.
8. D2
• The pancreatic duct and
common bile duct enter
the descending
duodenum through the
major duodenal papilla
(ampulla of Vater).
• This part of the
duodenum also
contains the minor
duodenal papilla, the
entrance for the
accessory pancreatic
duct.
12. SMA Syndrome
Superior mesenteric artery (SMA)
syndrome, also known as Wilkie
syndrome, is an acquired vascular
compression disorder in which
acute angulation of the superior
mesenteric artery (SMA) results in
compression of the third part of
the duodenum, leading to
obstruction.
13. CLINICAL FEATURES
Acute presentation is usually characterized by signs and
symptoms of duodenal obstruction.
Chronic cases may present with long-standing vague abdominal
symptoms, early satiety and anorexia, or recurrent episodes of
abdominal pain, associated with vomiting
14. Cause
Under conditions of severe weight loss, this cushion around the SMA is
diminished, causing angulation and reduction in the distance between the
aorta and the superior mesenteric artery. This is usually associated with
conditions causing significant weight loss such as:
-anorexia nervosa
-malabsorption
-hypercatabolic states (burns, major surgery)
-Cancer cachexia
15.
16. Nutcracker syndrome
Nutcracker syndrome is a vascular compression
disorder that refers to the compression of the
left renal vein most commonly between
the superior mesenteric artery (SMA) and aorta.
This can lead to renal venous hypertension,
resulting in rupture of thin-walled veins into the
collecting system with resultant hematuria.
Chronic Renal vein compression can cause renal
vein thrombosis.
18. arterial supply
• duodenal cap (first 2.5 cm):
right gastric artery, right
gastroepiploic artery
• remaining D1 to mid-D2:
superior pancreaticodudenal
artery (branch of gastroduodenal
artery)
• mid-D2 to ligament of Treitz:
inferior pancreaticoduodenal
arteries (branch of SMA)
19.
20. Valvulae conniventes
• The valvulae conniventes, aka (Kerckring
folds/plicae circulares/small bowel folds)
• the mucosal folds of the small intestine,
• starting from the second part of
the duodenum,
• they are large and thick at the jejunum and
considerably decrease in size distally in the
ileum to disappear entirely in the distal ileal
bowel loops.
• They result in a classical appearance on
abdominal radiographs, barium studies and
CT scans.
21. Jejunum
• Jejunum-2 meter,
• Gross: the jejunum has a delicate feathery appearance, and is located in
the left upper abdomen.
• Compared to the ileum, the jejunum has more valvulae conniventes .
• Like the ileum, normal jejunal wall thickness is less than 3 mm.
22. ileum
• The ileum is 2-4 m in length
• and is separated from the caecum by the ileocaecal valve.
26. Blood supply of jejunum and ileum
• The arterial supply from
branches of the superior
mesenteric artery. The lowest
part of the ileum is also
supplied by the ileocolic
artery.
• The veins correspond to the
branches of the superior
mesenteric artery and drain
into the superior mesenteric
vein.
27.
28. Large intestine
• The large intestine can easily be distinguished from the
small intestine by:
• 1. Taeniae coli, three thickened bands of longitudinal
muscle
• 2. The sacculations of its walls between the taeniae,
called haustra.
• 3. Appendices epiploicae (omental appendages), the small
pouches of omentum filled with fat.
• 4. Much greater caliber.
29.
30. Three teniae coli
Thickened bands of smooth muscle representing most of the
longitudinal coat. (mesocolic, free and omental taeniae coli)
These begin at the base of the appendix as the thick
longitudinal layer of the appendix splits to form three
bands.
The teniae run the length of the large intestine, merging again at
the rectosigmoid junction into a continuous longitudinal layer
around the rectum.
•
:
31. The three taeniae coli of the caecum converge at the
base of the appendix and form a complete outer longitudinal
coat for it.
32. Appendix epiploica
• Fat-filled pockets of peritoneum projecting from
the visceral peritoneum on the surface of the
large intestine
• There are many appendices epiploices on the
large intestine (except the rectum) ; also known
as omental appendage.
33.
34. Haustra
• Multiple pouches in the wall of the large
intestine.
• Haustra form where the longitudinal
muscle layer of the wall of the large
intestine is deficient; also known as:
sacculations
35.
36. Appendix
The appendix arises from the posteromedial
surface of the cecum, approximately 2-3 cm
inferior to the ileocecal valve, where the 3
longitudinal bands of the taeniae
coli converge. It is a blind diverticulum which
is highly variable in length, ranging between
2 to 20 cm. The appendix lies on its
own mesentery, the mesoappendix .
The tip of the appendix can have a variable
position :
retrocecal (65-70%)
pelvic (25-30%)
pre- or post-ileal (5%)
promontory
paracaecal
subcecal
37.
38. DIFFERENCES BETWEEN THE RIGHT TWO-THIRD AND LEFT ONE-THIRD OF THE
TRANSVERSE COLON
Features
Right two-third of
transverse colon
Left one-third of
transverse colon
Development From midgut From hindgut
Arterial supply
Middle colic artery, a
branch of superior
mesenteric artery (artery of
midgut)
Left colic artery, a
branch of inferior
mesenteric artery
(artery of hindgut)
Nerve supply By vagus nerves
By pelvic splanchnic
nerves
39. Coeliac axis angiogram.
1. Catheter in aorta
2. Catheter tip in coeliac trunk
3. Splenic artery
4. Left gastric artery
5. Common hepatic artery
6. Hepatic artery proper
7. Left hepatic artery
8. Right hepatic artery
9. Right gastric artery
10. Cystic artery
11. Gastroduodenal artery
12. Right gastroepiploic artery
13. Left gastroepiploic artery
14. Posterior superior
pancreaticoduodenal artery
15. Anterior superior
pancreaticoduodenal artery
16. Dorsal pancreatic artery
17. Transverse pancreatic artery
18. Gastric branches of gastroepiploic
artery
19. Phrenic branch of left hepatic artery
20. Contrast in right renal pelvis
40. Superior mesenteric angiogram.
The inferior pancreaticoduodenal
artery
(not shown) also arises from the
proximal
superior mesenteric artery and runs
superiorly.
1. Catheter in aorta
2. Superior mesenteric artery
3. Jejunal branches
4. Ileal branches
5. Terminal superior mesenteric artery
6. Ileocolic artery
7. Right colic artery
8. Middle colic artery running
superiorly
9. Contrast-filled bladder
41. Inferior mesenteric angiogram.
1. Catheter in right common iliac artery
2. Catheter in aorta
3. Inferior mesenteric artery
4. Left colic artery
5. Sigmoid arteries
6. Marginal artery of Drummond
7. Superior rectal artery and branches
8. Middle rectal artery (filling by reflux:
a branch of the internal iliac artery)
9. Gas in ascending colon
10. Descending colon
11. Sigmoid colon
12. Rectum
42. superior mesenteric artery (SMA): supplies the right
colon from the cecum to the splenic flexure
inferior mesenteric artery (IMA): supplies the left
colon from the splenic flexure to the rectum
Watershed areas :
splenic flexure (Griffiths point)
rectosigmoid junction (Sudeck point)
Low flow states and non-occlusive vessel disease are
most common and typically lead to ischemic colitis in
watershed areas.
WATERSHED AREAS
46. EMBRYOLOGY
1. At about 4-5 weeks of gestation, the primitive pancreas is formed by a dorsal pancreatic and ventral
pancreatic bud that arises from the endodermal lining of the duodenum.
2.At 6 weeks, the ventral bud and the bile duct rotate clockwise behind the duodenum
3.The ventral pancreatic bud lays posteroinferior to the dorsal pancreatic bud.
4. By about 7 weeks, upon reaching its final destination, the dorsal pancreatic bud fuses with the ventral
pancreatic bud to form the final pancreas
47. The ventral pancreatic bud
forms the posterior part of the
head and the uncinate
process.
The dorsal pancreatic bud
forms the anterior part of the
head, body and tail of the
pancreas.
49. The main pancreatic duct (Wirsung) is
formed from the ventral duct and the
distal portion of the dorsal duct.
The accessory duct (Santorini) may be
present due to the persistence of the
proximal portion of the dorsal pancreatic
duct.
51. • Rare anomaly.
Results from a failure of the dorsal pancreatic bud to form
the anterior head, neck, body, and tail of the pancreas.
Clinical presentation: Most patients are asymptomatic.
Patients with this anomaly may present with nonspecific
abdominal pain, diabetes mellitus, steatorrhea, or jaundice.
Agenesis of the Dorsal Pancreas
Illustration shows the posterior portion of
the head and the absence of the dorsal
pancreas
52. Agenesis of the dorsal pancreas on computed tomography (CT). (a, b) Axial view of a contrast-enhanced CT of the
abdomen reveals a normal head (arrows) of the pancreas and the absence of the body and tail. Note the presence
of mild dilatation of the distal common bile duct (arrowhead)
53. Hypoplasia of the Dorsal
Pancreas
Absence of the distal body and tail of
the pancreas.
Clinical presentation: Usually an
incidental finding by cross-sectional
imaging.
Most patients are asymptomatic
54. Hypoplasia of the dorsal pancreas on contrast-
enhanced CT (CECT). (a, b) Axial view and (c) coronal
view show the absence of the distal body and tail of the
pancreas (arrows). Note the truncated appearance of
the distal pancreas (curved arrows)
56. • Most common congenital pancreatic ductal anatomic
variant-upto 14%
• Pathogenesis:
ventral bud failed to fuse with dorsal bud during fetal
development(6-8th wk of gestation).
dorsal pancreatic duct drains most of the pancreatic glandular
parenchyma via the minor papilla
57. The pancreatic head and uncinate process are drained by the duct of Wirsung through the major papilla.
The body and tail of the pancreas are drained by the duct of Santorini through the minor papilla.
58. Clinical presentation: Most patients with pancreatic divisum are
asymptomatic.
This anomaly can be associated with recurrent episodes of pancreatitis.
It is postulated that in pancreatic divisum, the duct of Santorini, and the
minor papilla are too small to adequately drain the pancreatic secretions
produced by the pancreatic body and tail.
59.
60. Pancreatic divisum on CECT. (a) Coronal and (b) axial views of a CECT of the abdomen with 3D volume-
rendering reformatted images reveal a prominent duct of Santorini (arrows) running parallel to the duct of
Wirsung (arrowheads) and absence of connection between these ducts
61.
62. Pancreatic divisum on MRCP. (a) Coronal view of an MRCP show a prominent dorsal duct draining through the minor
papilla (arrows) and a smaller ventral duct draining through the major papilla (arrowheads)
63. Pancreatic divisum associated with chronic pancreatitis. A forty-five-year-old female with
history of chronic epigastric pain and steatorrhea. Coronal view of MRCP thick slab
demonstrates a beaded dilated dorsal duct (arrows). The ventral duct appears slightly
prominent and does not communicate with the dorsal duct.
64. Annular Pancreas
• Rare congenital anomaly in
which incomplete rotation of the
ventral Pancreatic bud leads to a
segment of the pancreas
encircling the second part of the
duodenum.
Annular pancreas. Illustration shows a ring of pancreatic
tissue encircling the second portion of the duodenum
65. Location
Second portion of the duodenum (85 %)
First or third portions of the duodenum (15 %)
Classification
Complete band (25 %)
Incomplete band (75 %)
66. Associated congenital abnormalities (75 %):
Esophageal atresia
Imperforate anus
Congenital heart disease
Malrotation of the midgut
Down syndrome
67. 50 % of the patients develop gastrointestinal or biliary obstruction during
the first year of life.
Adult patients may be asymptomatic for life and it may be discovered
incidentally.
.
This anomaly may be associated with gastric outlet obstruction, peptic
ulcers, gastrointestinal bleeding, acute or chronic pancreatitis, or biliary
obstruction.
Patients may complain of abdominal pain, postprandial fullness, vomiting,
or jaundice.
CLINICAL FEATURES
68. • Two types of annular pancreas: extramural and intramural.
• Extramural type, the ventral pancreatic duct encircles the
duodenum to join the main pancreatic duct.
• Intramural type, the pancreatic tissue is intermingled with
muscle fibers in the duodenal wall, and small ducts drain
directly into the duodenum.
69.
70. Annular pancreas gross appearance. Annular pancreas found incidentally in a patient that underwent a pancreaticoduodenectomy
for a small ampullary carcinoma. (a–c) Photographs of the gross specimen show a band of pancreatic tissue completely encircling
the second portion of the duodenum
71. Annular pancreas on plain abdominal films. (a, b) Flat abdominal films from two neonates with intractable
vomiting demonstrating distention of the stomach (S), as well as distention of the first portion of the
duodenum (D) “double bubble” sign
72. Annular pancreas on barium upper gastrointestinal series (UGI) and computed tomography. (a) UGI
examination shows an eccentric narrowing in the second portion of the duodenum (arrows). (b) Contrast-
enhanced CT shows a rim of pancreatic tissue (arrows) surrounding the contrast-filled duodenum
73. Annular pancreas on contrast-enhanced CT. (a) Axial, (b) coronal, and (c–d) oblique 3D volume-rendered
reconstructions demonstrate a band of pancreatic tissue (arrows) completely encircling the second portion
of the duodenum associated with luminal narrowing (arrowheads)
74. Annular pancreas associated with chronic pancreatitis. A 62-year-old male with history of chronic epigastric pain. MRCP
thick slab demonstrates a pancreatic duct encircling the duodenum (arrowhead). Note the dilatation and beaded
appearance of the main pancreatic duct (arrows)
75. Annular pancreas on ERCP. Fluoroscopic image after the injection of contrast into the main pancreatic duct
demonstrates a small duct originating from the main pancreatic duct and partially encircling the second portion of the
duodenum
