GI: Malrotation, Volvulus & Appendicitis

Question 1

What does malrotation refer to?

Answer 1

During embryogenesis, the midgut undergoes abnormal rotation and fixation.

This misplacement of the gut makes it susceptible to volvulus and duodenal compression by peritoneal bands (Ladd bands)

Question 2

What is the most common presentation of malrotation?

Answer 2

Bilious vomiting within the 1st day of life

Question 3

Give 4 differentials for malrotation

Answer 3

1) GORD

2) Pyloric stenosis

3) Duodenal atresia

4) Intestinal obstruction

Question 4

What is the gold standard investigation for diagnosing malrotation?

Answer 4

Upper GI contrast study.

Question 5

What will an upper GI contrast study show in malrotation?

Answer 5

Will reveal the obstructon point as no contrast can pass distally from thislocation.

The proximal bowel may demonstrate a corkscrew appearance.

Question 6

Management of malrotation?

Answer 6

Urgent surgical intervention to relieve the obstruction and correct the anatomical abnormality.

Question 7

Define volvulus

Answer 7

Torsion of the colon around its mesenteric axis, resulting in compromised blood flow and closed loop obstruction.

Question 8

What is the most common type of volvulus?

Answer 8

Sigmoid (80%)

Question 9

What is sigmoid volvulus?

Answer 9

Describes large bowel obstruction caused by the sigmoid colon twisting on the sigmoid mesocolon.

Question 10

What are the 2 types of volvulus?

Answer 10

1) sigmoid (80%)

2) caecal (20%)

Question 11

Why are most people not at risk of caecal volvulus?

Answer 11

In most people (around 80%) the caecum is a retroperitoneal structure so not at risk of twisting.

In the remaining minority there is however developmental failure of peritoneal fixation of the proximal bowel putting these patients at risk of caecal volvulus.

Question 12

What are some associations with sigmoid volvulus?

Answer 12

• older patients
• chronic constipation
• Chagas disease
• neuro e.g. Parkinson’s disease, Duchenne muscular dystrophy
• psych e.g. schizophrenia

Question 13

What are some associations with caecal volvulus?

Answer 13

• all ages
• adhesions
• pregnancy

Question 14

Features of volvulus?

Answer 14

• constipation
• abdominal bloating
• abdominal pain
• nausea/vomiting

Question 15

What is appendicitis typically caused by?

Answer 15

Infection secondary to luminal obstruction with:

a) faecolith
b) impacted normal stool
c) lymphoid hyperplasia
d) a tumour

Question 16

Risk factors for appendicitis?

Answer 16

1) male sex
2) age 10-20y/o
3) FH
4) caucasian ethnicity

Question 17

Luminal obstruction leading to appendicitis can be caused by what 4 things?

Answer 17

1) Faecaliths

2) Lymphoid hyperplasia

3) Foreign bodies

4) Tumours

Question 18

Clinical features of acute appendicitis?

Answer 18

1) peri-umbilical abdominal pain: migrates from centre to RIF

2) pain worse on coughing or going over speed bumps

3) vomit once or twice but marked and persistent vomiting is unusual

4) mild pyrexia

5) anorexia

Question 19

Exam findings in acute appendicitis?

Answer 19

1) generalised peritonitis: rebound and percussion tenderness, guarding and rigidity

2) PR exam: causes right-sided tenderness

3) Rovsing’s sign (palpation in the LIF causes pain in the RIF)

4) Psoas sign: pain on extending hip if retrocaecal appendix

Question 20

Management of acute appendicitis?

Answer 20

1) appendicectomy

2) broad spectrum IV antibiotics

3) if perforated: copious abdominal lavage.

Question 21

Complications of appendicitis?

Answer 21

1) Perforation

2) Abscess formation

3) Phelgmon

4) Peritonitis

5) Postop complications

6) Sepsis

Question 22

What is a phlegmon?

Answer 22

An inflammatory mass formed by a localised infection and oedema, often seen in the early stages of appendiceal perforation.

Question 23

What are the key differentials of appendicitis?

Answer 23

1) ectopic
2) ovarian cyst
3) meckel’s diverticulum
4) mesenteric adenitis
5) appendix mass

Question 24

What is an appendix mass?

Answer 24

An appendix mass occurs when the omentum surrounds and sticks to the inflamed appendix, forming a mass in the right iliac fossa

Question 25

What is Meckel’s diverticulum?

Answer 25

A malformation of the distal ileum that occurs in around 2% of the population.

It is usually asymptomatic, however it can bleed, become inflamed, rupture or cause a volvulus or intussusception.

They are often removed prophylactically if identified incidentally during other abdominal operations.