Volvulus Flashcards
What is volvulus?
Rotation of a loop of bowel around the axis of its mesentery that results in bowel obstruction + potential ischaemia.
Which areas are commonly affected in volvulus?
Sigmoid colon: 80% (long mesentery)
Caecum: 20%
Volvulus Neonatorum: occurs in neonates, normally midgut
Why is caecal volvulus less common?
In most people (80%) the caecum is a retroperitoneal structure so not at risk of twisting
What obstruction is caused by caecal volvulus?
Most proximal part of large bowel hence will not really cause LBO but may cause SBO
List 5 risk factors for sigmoid volvulus
Elderly
Chronic constipation
Neurological disorders (PD, DMD)
Psychiatric disease (those on anti-psychotics)
Chagas disease (parasite)/ other Parasitic infections
What increases risk of sigmoid volvulus?
RFs increase chance of having chronic constipation + slow transit
Results in development of redundant sigmoid colon which becomes prone to twisting
Give 3 caecal volvulus associations
All ages
Adhesions
Pregnancy
How does volvulus differ from other causes of bowel obstruction?
Rapidity of onset (few hours)
+
Degree of abdominal distension
What causes volvulus in neonates?
Malrotation: incomplete rotation of the midgut causing a failure in the attachment of the caecum to the posterior abdominal wall
List 4 symptoms of volvulus
Absolute constipation
Abdominal bloating
Abdominal pain
Vomiting (late, secondary to BO)
List 2 signs of volvulus
Abdominal distension (tympanic to percussion)
Tinkling bowel sounds (intestinal obstruction)
What is seen on abdominal x-ray in sigmoid volvulus?
Coffee bean sign
LBO (large, dilated loop of colon, often with air-fluid levels)
What is seen on abdominal x-ray in caecal volvulus?
Embryo sign
SBO
What is first line imaging in volvulus?
AXR
What imaging provides a definitive diagnosis of sigmoid volvulus? What is seen?
CT AP with contrast
Whirl sign
What bloods should be performed in suspected volvulus?
FBC
U+Es
CRP
Clotting
VBG: pH + serum lactate in context of potential bowel ischaemia
Describe initial management of sigmoid volvulus
Insert NG tube + urinary catheter
IV fluids
Analgesia
Describe conservative management of sigmoid volvulus
Decompression by sigmoidoscope + insertion of flatus tube
Describe sigmoidoscope decompression
- Patient in left lateral position, lubricated sigmoidoscope inserted into rectum
- Manoeuvred to locate twisted bowel + with gentle pressure volvulus untwisted
- Once sigmoidoscope in correct position there will be a rush of air + liquid faeces as obstruction is relieved
Describe use of a flatus tube
Flatus tube often left in situ (up to 24h) after initial decompression to allow continued passage of contents + aid recovery of affected area
When is emergency surgery indicated for sigmoid volvulus?
If evidence of bowel ischaemia or perforation
If repeat failed endoscopic decompression
What surgery is usually performed if required for sigmoid volvulus?
Sigmoid colectomy
Often as a laparotomy + Hartmann’s procedure
What may patients with recurrent volvulus choose to undergo?
Elective procedure
Either sigmoid colectomy with primary anastomosis or end colostomy
Give 2 complications of sigmoid volvulus
Bowel ischaemia + perforation
Recurrence
