3. GI (Upper GI/Small Bowel)

Question 1

Afferent loop syndrome (6)

Answer 1

Uncommon complication post Billroth 2 (partial gastrectomy, greater curvature of stomach connected to duodenum).
Commonest cause is obstruction (adhesions, tumour, intestinal hernia) of afferent loop.
Acute form may have closed loop obstruction.
Afferent obstruction leads to build up of billiary, pancreatic and intestinal secretions, causing afferent limb dilatation.
Back pressure dilates gallbladder and causes pancreatitis.
Another cause is if stomach preferentially drains into afferent loop.

Question 2

Jejunogastric intusussception

Answer 2

Rare complication of gastroenterostomy.
Jejunum herniates back into stomach (usually efferent limb), causes gastric obstruction.
Acute form has high mortality.

Question 3

Bile reflux gastritis.

Answer 3

Fold thickening and filling defects in stomach after Billroth 1 or 2 likely due to bile acid reflux.

Question 4

Gastro-gastric fistula (2)

Answer 4

Seen in Roux-en-Y patients who gain weight years later.
Anastamotic breakdown is chronic and often not painful.

Question 5

Cancer

Answer 5

3-6x more likely to get adenocarcinoma in gastric remnant after old peptic ulcer surgeries (billroths)

Question 6

Small bowel folds - types (3)

Answer 6

Thin straight folds within a dilated lumen.
Thick (>3mm) straight folds, can be diffuse or segmental.
Thick nodular folds, can be diffuse or segmental.

Question 7

Thin folds with dilatation - causes (4)

Answer 7

Mechanical obstruction.
Paralytic ileus.
Scleroderma.
Sprue

Question 8

Thick folds without nodularity - causes (7)

Answer 8

Segmental:
- Ischaemia
- Radiation
- Haemorrhage
- Adjacent inflammation
Diffuse
- Low protein
- Venous congestion
- Cirrhosis

Question 9

Thick folds with nodularity - causes (9)

Answer 9

Segmental
- Crohn’s
- Infection
- Lymphoma
- Mets
Diffuse
- Whipples
- Lymphoid hyperplasia
- Lymphoma
- Mets
- Intestinal Lymphangectasia

Question 10

Filling defects - DDx (2)

Answer 10

Uniform 2-4mm nodules = Lymphoid hyperplasia.
Larger/varied size nodules = Cancer, probably mets and therefore probably melanoma)

Question 11

Loop separation DDx (6)

Answer 11

Without tethering
- Ascites
- Wall thickening (Crohn’s, lymphoma)
- Adenopathy
- Mesenteric tumours
With tethering
- Carcinoid.
Extrinsic processes will spare the mucosa, intrinsic processes with alter the mucosa

Question 12

Target sign - Causes (7)

Answer 12

Single target
- GIST
- Primary adenocarcinoma
- Lymphoma
- Ectopic pancreas
- Met (melanoma)
Multiple target
- Lymphoma
- Mets (melanoma)

Question 13

Whipples (5)

Answer 13

Rare infection by Tropheryma Wipplei.
Prefers white men in 50s.
Infiltrates lamina propria causing marked swelling of intestinal villi and thickened irregular mucosal folds of the duodenum and proximal jejunum.
“Sand like nodules” - diffuse micronodules in jejunum.
Causes low density (near fat) enlarged lymph nodes.

Question 14

Pseudo whipples (2)

Answer 14

MAI infection, seen in AIDS (CD4 <100).
Nodules in jejunum + splenomegaly and retroperitoneal lymph nodes.

Question 15

Coeliac sprue - features (6)

Answer 15

Small bowel malabsorption of gluten.
Can cause Fe malabsorption leading to anaemia.
Associated with idiopathic pulmonary haemosiderosis (Lane Hamilton syndrome).
Increased risk of bowel wall lymphoma.
Gold standard diagnostic test is biopsy.
Associated with Dermatitis Herpetiformis.

Question 16

Coeliac sprue - imaging (4)

Answer 16

“Fold Reversal” - Jejunal folds look like ileum and vice versa.
Moulage sign - dilated bowel with effaced folds (tube with wax poured in it).
Cavitary lymph nodes (low density).
Splenic atrophy.

Question 17

Intestinal Lymphangiectasia (3)

Answer 17

Lymphangiectasia due to obstruction in lymph flow from small intestine to mesentery.
Causes dilatation of intestinal and serosal lymphatics.
Can be primary (lymphatic hypoplasia) or secondary (thoracic duct obstruction)

Question 18

SMA syndrome (2)

Answer 18

Obstruction of D3 by SMA.
Classically patients who’ve lost a lot of weight recently.

Question 19

Graft vs Host (5)

Answer 19

Ribbon like bowel is buzzword.
Occurs after bone marrow transplant.
Less common with modern, anti-rejection drugs.
Skin, liver, GI tract affected.
Small bowel usually most severely affected, bowel is featureless, atrophic and fold thickening (ribbon like)

Question 20

Meckel’s diverticulum (4)

Answer 20

Congenital diverticulum of distal ileum.
It’s a persistent piece of omphalomesenteric duct.
Rule of 2s:
- 2% of population,
- 2 types of heterotopic mucosa (gastric and pancreatic),
- 2 feet from IC valve,
- 2 inches long,
- 2cm diameter,
- symptoms before 2yo.
Gastric mucosa ones tend to bleed and take up Tc-Pertechnate like stomach.

Question 21

Meckels complications (4)

Answer 21

Can get diverticulitis in Meckels (mimics appendicitis).
GI bleed from gastric mucosa (30% of symptomatic cases).
Can be lead point for intussusception (seen with inverted diverticulum).
Can cause obstruction.

Question 22

Duodenal inflammatory disease (4)

Answer 22

Can get fold thickening if duodenum (from adjacent inflammation of pancreas or GB).
Can also get fold thickening and fistula formation with crohn’s (colon is primary site).
Primary duodenal crohn’s can happen but rare.
Chronic dialysis patients may get severely thickened duodenal folds, can mimic appearance of pancreatitis on barium.

Question 23

Jejunal diverticulosis (3)

Answer 23

Less common than colonic diverticula.
Occurs along mesenteric border.
Association with bacterial overgrowth and malabsorption.

Question 24

Small bowel cancer - types (4)

Answer 24

Adenocarcinoma,
Lymphoma,
Carcinoid,
Mets.

Question 25

Small bowel adenocarcioma (4)

Answer 25

Commonest in proximal small bowel (usually duodenum).
Increased incidence with coeliac disease and regional enteritis.
Focal circumferencial bowel wall thickening in proximal small bowel is characteristic on CT.
Duodenal web does NOT increase risk.

Question 26

Small bowel lymphoma (5)

Answer 26

Usually non-hodgkins.
Coeliac, crohn’s, AIDS and SLE are higher risk.
Can have any appearance.
Usually do NOT obstruct.
Hodgkin lymphoma more likely to cause desmoplastic reaction.

Question 27

Carcinoid of small bowel (4)

Answer 27

Mass + desmoplastic stranding.
“Starburst” appearance of mesenteric mass with calcifications.
Most commonly in young adults.
Primary tumour often not seen (calcifications is the desmoplastic reaction).

Question 28

Small bowel carcinoid - trivia/associations (5)

Answer 28

Liver mets often hypervascular. Don’t get carcinoid syndrome (flushing, diarrhoea) until liver mets.
Most commonly in distal appendix, then terminal ileum.
Appendix has best prognosis.
Systemic serotonin degrates right sided heart valves, causing tricuspid regurg.
MIBG or Octreotide scans help with diagnosis and staging.

Question 29

Small bowel mets (3)

Answer 29

Usually melanoma (affects small bowel in 50% of fatal cases).
Haematogenous seeding of small bowel also occurs with breast, lung and kaposi sarcoma.
Melanoma classically has multiple targets.

Question 30

Inguinal hernias (5)

Answer 30

Most common abdominal wall hernia. M:F = 7:1.
Direct vs Indirect:
- Direct less common.
- Medial vs Lateral to inferior epigastric artery.
- Defect in Hesselback triangle vs Failure of processus vaginalis to close.
- NOT covered by internal spermatic fascia vs Covered by internal spermatic fascia.

Question 31

Femoral hernia (3)

Answer 31

Likely to obstruct.
Seen in older women.
Medial to femoral vein and posterior to inguinal ligament. Usually right side.

Question 32

Obturator hernia (3)

Answer 32

Older women.
Often pts with increased intra-abdominal pressures (Ascites, COPD).
Usually asymptomatic but can strangulate

Question 33

Lumbar hernia (4)

Answer 33

Can be superior (Grynfeltt-Lesshaft) through superior lumbar triangle.
Can be inferior (Petit) through inferior lumbar triangle.
Superior is more common, but both are otherwise similar.
Congenital or acquired (post surgery or acquired)

Question 34

Spigelian hernia

Answer 34

Occurs along the semilunar line through the transversus abdominis, close to level of arcuate line.

Question 35

Littre hernia

Answer 35

Hernia with a meckel diverticulum in it

Question 36

Amyand hernia

Answer 36

Hernia with appendix in it

Question 37

Richter hernia (2)

Answer 37

Contains only one wall of bowel and therefore does NOT obstruct.
Higher risk of strangulation though.

Question 38

Hernias post laparoscopic Roux-en-Y - causes (2)

Answer 38

Factors promoting hernia by bypass:
- Laparoscopic vs open: Laparoscopic creates less adhesions, so you have more mobility.
- Degree of weight loss: more weight loss = less protective, space occupying mesenteric fat.

Question 39

Hernias post laparoscopic Roux-en-Y - sites (3)

Answer 39

• At the defect in transverse mesocolon, through which the Roux loop passes (if done in retrocolic position).
• At the mesenteric defect at the enteroenterostomy.
• Behind the Roux limb mesentery placed in a retrocolic or antecolic position (retrocolic petersen and anterocolic petersen type).

Question 40

Internal hernia (4)

Answer 40

Commonest manifestation is closed loop obstruction, often with strangulation.
9 different subtypes.
Herniation of viscera through peritoneum or mesentery.
Herniation occurs through known anatomic foramen or recess, or one created post operatively.

Question 41

Intestinal hernia - left paraduodenal hernia (5)

Answer 41

2 kinds - right or left.
Most common types of internal hernia.
75% occur on left.
Occur in the duodenojejunal junction (Fossa of Landzert).
Herniated small bowel can become trapped in sac of bowel, between pancreas and stomach, left of ligement of Treitz.
Sac characteristically contains the IMV and left colic artery.

Question 42

Intestinal hernia - right paraduodenal hernia (2)

Answer 42

Right sided ones occur just behind SMA and below transverse segment of duodenum in the Fossa of Waldeyer.
Classically non rotated small bowel with normally rotated large bowel.