GI: Malrotation, Volvulus & Appendicitis Flashcards
What does malrotation refer to?
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)
What is the most common presentation of malrotation?
Bilious vomiting within the 1st day of life
Give 4 differentials for malrotation
1) GORD
2) Pyloric stenosis
3) Duodenal atresia
4) Intestinal obstruction
What is the gold standard investigation for diagnosing malrotation?
Upper GI contrast study.
What will an upper GI contrast study show in malrotation?
Will reveal the obstructon point as no contrast can pass distally from thislocation.
The proximal bowel may demonstrate a corkscrew appearance.
Management of malrotation?
Urgent surgical intervention to relieve the obstruction and correct the anatomical abnormality.
Define volvulus
Torsion of the colon around its mesenteric axis, resulting in compromised blood flow and closed loop obstruction.
What is the most common type of volvulus?
Sigmoid (80%)
What is sigmoid volvulus?
Describes large bowel obstruction caused by the sigmoid colon twisting on the sigmoid mesocolon.
What are the 2 types of volvulus?
1) sigmoid (80%)
2) caecal (20%)
Why are most people not at risk of caecal volvulus?
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.
What are some associations with sigmoid volvulus?
- older patients
- chronic constipation
- Chagas disease
- neuro e.g. Parkinson’s disease, Duchenne muscular dystrophy
- psych e.g. schizophrenia
What are some associations with caecal volvulus?
- all ages
- adhesions
- pregnancy
Features of volvulus?
- constipation
- abdominal bloating
- abdominal pain
- nausea/vomiting
What is appendicitis typically caused by?
Infection secondary to luminal obstruction with:
a) faecolith
b) impacted normal stool
c) lymphoid hyperplasia
d) a tumour
Risk factors for appendicitis?
1) male sex
2) age 10-20y/o
3) FH
4) caucasian ethnicity
Luminal obstruction leading to appendicitis can be caused by what 4 things?
1) Faecaliths
2) Lymphoid hyperplasia
3) Foreign bodies
4) Tumours
Clinical features of acute appendicitis?
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
Exam findings in acute appendicitis?
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
Management of acute appendicitis?
1) appendicectomy
2) broad spectrum IV antibiotics
3) if perforated: copious abdominal lavage.
Complications of appendicitis?
1) Perforation
2) Abscess formation
3) Phelgmon
4) Peritonitis
5) Postop complications
6) Sepsis
What is a phlegmon?
An inflammatory mass formed by a localised infection and oedema, often seen in the early stages of appendiceal perforation.
What are the key differentials of appendicitis?
1) ectopic
2) ovarian cyst
3) meckel’s diverticulum
4) mesenteric adenitis
5) appendix mass
What is an appendix mass?
An appendix mass occurs when the omentum surrounds and sticks to the inflamed appendix, forming a mass in the right iliac fossa
What is Meckel’s diverticulum?
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.
