What is a volvulus?
Twisting of a loop of intestine around its mesenteric attachment, resulting in a closed loop bowel obstruction.
Derived from the Latin “To twist”
At what location within the bowel do most volvulus develop?
Sigmoid colon
Aside from the colon, where else can a volvulus rarely form?
- Stomach
- Caecum
- Small intestine
- Transverse colon
Why is sigmoid volvulus more common than any other type of volvulus?
The long mesentery of the sigmoid colon (which increases w/ age) means that this location is more prone to twisting on its mesenteric base to form a volvulus.
What are risk factors for volvulus?
- Increasing age
- Neuropsychiatric disorders
- Resident in a nursing home
- Chronic constipation / laxative use
- Male gender
- Prev. abd operations
What are the symptoms of sigmoid volvulus?
Rapid onset of symptoms of large bowel obstruction
- Colicky abd pain
- Obstipation
- Abdominal distension (sudden & significant)
- Vomiting (occurs late in presentation
What are the signs found on examination?
- Tympanic abdomen upon percussion
- May have signs of perforation / peritonism / ischaemia (Surgical emergency)
- Guarding
- Pain worsened by movement
- Focal tenderness
- Pyrexia
What are differentials for volvulus?
- Alternative causes for bowel obstruction
- Malignancy, Diverticular disease, Hernias, Adhesions
- Severe constipation
- Pseudo-obstruction
- Severe sigmoid diverticular disease.
How do you investigate a case of suspected sigmoid volvulus?
- Routine bloods = FBC, U&Es, LFTs, CRP, G&S
inc. Ca2+, and TFTs to exclude any potential pseudo-obstruction - CT abdo-pelvis with contrast
- Initial investigation for suspected bowel obstruction
- Shows a very dilated sigmoid colon with a ‘whirl sign’, from the twisting mesentery around its base.
- Abdominal radiograph (AXR)
- Typically shows a “coffee-bean sign” arising from the left iliac fossa
- May also show signs of small bowel dilatation if the ileocaecal valve is incompetent.
What is the management of a patient presenting with sigmoid volvulus?
- Fluid resuscitation
- Sigmoidoscope decompression&insertion of a flatus tube
- Surgical management
- Usually laparotomy for Hartmann’s procedure
- Healthy patients w/ recurrent volvulus may choose to have an elective procedure (most commonly sigmoidectomy w/ primary anastomosis) to prevent further recurrence.
What are the indications for surgery?
- Colonic ischaemia or perforation
- Repeated failed attempts at decompression
- Necrotic bowel noted at endoscopy
How does sigmoidoscope decompression w/ insertion of flatus tube work?
Patient is placed in the left lateral position and a lubricated sigmoidoscope is gently guided into the rectum & manoeuvred to locate the twisted bowel. Once in the correct position, there will be a rush of air & liquid faeces as the obstruction is relieved.
A flatus tube is often left in situ for up to 24 hours after initial decompression to allow for the continued passage of contents and aid recovery of the affected area
How do you decide what operation to perform?
Depends on
- Patient’s nutritional status
- Adequacy of blood supply
- Haemodynamic stability
- Presence of any perforation / peritonitis
What are the complications of volvulus?
- Bowel ischaemia / perforation (Main & immediate complication)
- Risk of recurrence (occurring in up to 90% of patients)
- Stoma complications (if placed)
What is the mortality like in sigmoid volvulus & why?
High mortality because:
- Pts are typically old / frail / suffering from co-morbidities
- Delay in getting patients to theatre
What is the second most common site for a volvulus?
Also provide the:
- Incidence
- Diagnostic investigation
- Management
Caecum
Incidence
- 25-40% of all colonic volvulus.
- Bimodal age of onset:
- 10-29 yo
- Typically due to intestinal malformation or excessive exercise
- 60-79 yo.
- Typically associated w/ chronic constipation, distal obstruction or dementia
- 10-29 yo
Diagnostic investigation
- CT abdo-pelvis w contrast
- Shows a very distended caecum, a mesenteric “swirl” and small bowel obstruction
Management
- Laparotomy and ileocaecal resection (if patient is fit enough)
