[19] Volvulus Flashcards
What is a volvulus?
The twisting of a loop of intestine around its mesenteric attachment, resulting in a closed loop obstruction
What happens to the affected bowel in a volvulus?
It can often become ischaemic due to a compromised blood supply, rapidly leading to bowel necrosis and perforation
Where do most volvuli occur?
At the sigmoid colon
What is the importance of volvuli?
It is the leading cause of bowel obstruction in many developing countries, and is tUKhe third most common cause in the UK and USA
What are the most common causes of bowel obstruction in the UK?
Maligancy and diverticular disease
Where else can volvuli occur?
Stomach
Small intestine
Caecum
Transverse colon
Why is the sigmoid colon most likely to get a volvulus?
Because the long mesentery of the sigmoid colon means that this segment of bowel is prone to twisting on its mesenteric base to form a volvulus
What are the risk factors for developing a volvulus?
Neuropsychiatric conditions Resident in nursing home Advanced age Chronic constipation or laxative Male gender Previous abdominal surgeries Diabetes mellitus
How will patients with a volvulus present?
With the clinical features of a bowel obstruction
How can the recurring nature of volvuli be relevant?
Means that the patient may have had a previous history of volvulus formation
What is the result of the distal location of the sigmoid colon on the presentation of a volvulus?
Vomiting is usually a late sign
Colicky pain, abdominal distention, and absolute constipation occur earlier
What will be found on examination in a volvulus?
The abdomen will be markedly distended, with increased bowel sounds and tympanic percussion
What should you be sure to examine for with a suspected volvulus?
Signs of perforation or generalised peritonism
Why is it important to examine for signs of perforation or generalised peritonism in a suspected volvulus?
As this is a surgical emergency
What are the main differential diagnoses to consider in a suspected volvulus?
Other causes of bowel obstruction, as well as severe constipation, pseudo-obstruction, and severe sigmoid diverticular disease
What investigations should be done in suspected volvulus?
Routine bloods
Imaging
What bloods should be checked in suspected volvulus?
Electrolytes
Calcium
TFTs
What is the purpose of checking TFTs in a suspected volvulus?
To exclude any pseudo-obstruction
What is the most decisive initial investigation for a suspected sigmoid volvulus?
An abdominal x-ray
What will be shown on abdominal x-ray in volvulus?
Will classically show a ‘coffee-bean sign’, arising from the left iliac fossa
What % of cases of volvulus have the coffee bean sign?
60-75% cases
What will be seen on a AXR in volvulus if the ileocaecal valve is incompetent?
There will be signs of small bowel dilation
When might a CT scan be warranted in suspected volvulus?
If the diagnosis remains unclear, or clinical features suggest a potential bowel ischaemia developing
What will CT imaging classically show with a volvulus?
A ‘whirl sign’ from the twisting mesentery around it’s base
What can aid in any unclear diagnosis in suspected volvulus?
Barium enema
How should all patients with suspected sigmoid volvulus be managed initially?
As per any bowel obstruction
What is involved in the conservative management of a sigmoid volvulus?
Decompression with a sigmoidoscope, and insertion of a flatus tube
How is a sigmoidoscope decompression performed?
The patient is placed in the left lateral position, and a lubricated sigmoidoscope is gently guided into the rectum. It is maneuvered to locate the twisted bowel, and once the sigmoidoscope is in the correct position, there will be a rush of air and liquid faeces as the obstruction is relieved
How long is a flatus tube left in situ after initial decompression of a sigmoid volvulus?
Up to 24 hours
What is the purpose of a flatus tube after a sigmoid volvulus>
It allows continued passage of contents, and aids in recovery of the affected area
What % of sigmoidoscopic approaches may not be able to adequately locate the lead point for twisting?
24%
What may result from a sigmoidoscopic approach not being able to locate the lead point for twisting?
Colonoscopic approach may be required
What are the surgical options in the management of a sigmoid volvulus?
Either primary anastomosis or Hartmann’s procedure
What are the indications for surgical management of a sigmoid volvulus?
Repeated failed attempts at decompression
Necrotic bowel noted at endoscopy
Suspected or proven perforation or peritonitis
What will the decision of which operation to perform depend on?
The patients nutritional status
Adequacy of blood supply
Haemodynamic stability
Presence of any perforation or peritonitis
What may patients with recurrent volvulus, but who are otherwise healthy choose to do?
May choose to have an elective procedure to prevent further recurrence
What elective procedure may be used to prevent recurrence of a volvulus?
Most commonly a sigmoidectomy with primary anastomosis
What is the main immediate complication of a sigmoid volvulus?
Bowel ischaemia and perforation
What are the longer term complications of a sigmoid volvulus?
Risk of recurrence
Complications arising from any stoma placed
What is the risk of recurrence of a sigmoid volvulus?
Up to 90%
What is the second most common site for a volvulus?
Caecum
What % of colonic volvuli are caecal?
25-40%
At what age are caecal volvuli most common?
The age of those affected occurs in two peaks, 10-29 years, and 60-79 years
What causes caecal volvuli in younger patients?
Intestinal malformation
Excessive exercise
What causes caecal volvuli in older patients?
Chronic constipation
Distal obstruction
Dementia
How is a diagnosis of caecal volvulus made?
Initially via abdominal x-ray
What will be shown on abdominal x-ray with caecal volvulus?
Coffee bean sign, with lead point from right lower quadrant
What can aid in an unclear diagnosis of caecal volvulus?
Barium enema
What is involved in the conservative management of a caecal volvulus?
Endoscopic decompression
What is the success rate of endoscopic decompression of a caecal volvulus?
30%
What is involved in the surgical intervention for a caecal volvulus?
Detorsion and caecostomy
What is normally the primary treatment for a caecal volvulus?
Surgical management
Why is surgical management usually the primary treatment for a caecal volvulus?
Because of the higher chance of ischaemia in caecal volvulus
Is recurrence following surgery common in caecal volvulus?
No, it is rare
