Editing Sigmoid volvulus


"Twisting of the sigmoid colon causing obstruction"

== '''Epidemiology''' ==

* Causes about 10% of LBO
* Can be the initial     presentation of Hirschsprung disease

== '''Risk factors''' - mostly leading to chronic constipation ==

=== Patient ===

* Mean age 70
* Higher incidence in men
* Often institutionalised and      debilitated due to underlying neurologic or psychiatric disease
* History of constipation -      might cause elongation and dilation
* Can occur in younger      patients with abnormal colonic motility

=== Anatomical ===

* Long redundant sigmoid colon      with a narrow mesenteric attachment

== '''Pathophysiology''' ==

* Occurs when an air-filled     loop of sigmoid colon twists about its mesentery - usually clockwise
* Theorised to result from a     narrowing of mesenteric base, and absence of usual sidewall adhesions,     that can leave it vulnerable to twisting
* Obstruction of the lumen     occurs at 180 degrees, and impairment of perfusion occur at 360 degrees
** I think that some      radiologists think the 180 degree twist is not volvulus
* 'Ileosigmoid knotting' occurs     when the ileum wraps itself around the sigmoid, usually clockwise

== '''Presentation''' ==

* Insidious onset of slowly     progressive abdominal pain (continuous and severe, with superimposed     colic), nausea, distension, constipation
* Usually present 3-4 days     after symptom onset
* Might be 'emptiness' in LIF
* Fever, tachycardia,     hypotension, guarding, rigidity, and rebound tenderness indicate     perforation/peritonitis/reduced perfusion

== '''Imaging''' ==

* Classic sign on XR, inverted     U pointing to RUQ for sigmoid volvulus (which are 90% of them) - bent     inner tube sign
* Differentiating between     sigmoid and caecal volvulus on AXR
** Northern exposure sign -      apex of volvulus reaches above transverse - quite specific for sigmoid
** Caecal volvulus usually has      one air-fluid level, whereas sigmoid usually has 3+
** Look for LBO in sigmoid      volvulus
* Water-soluble enema - bird's     beak deformity
* CT is very specific and     sensitive - whirl sign at point of obstruction, bird's beak appearance of     afferent and efferent segments, absence of rectal gas

== '''Management''' ==

* Resuscitation
* Immediate surgery if there     are signs of peritonitis/bowel compromise
** Resect without detorting if      the bowel is strangulated, to avoid reperfusion injury
* Otherwise endoscopic     detorsion
** Can be done with either      rigid or flexi sig (flexi better, since you can see whether mucosa is      ischaemic). If you fail with rigid, can try with flexi.
** Leave a rectal tube in situ,      attached to a bag
** Successful in 60-90% of      patients, although 70% have recurrence, so should have definitive      operation in initial hospitalization. More likely to fail with caecum      >10cm or gangrene. Aim to operate within 24-48 hours if successful.      Operate immediately if unable to decompress endoscopically.
* Definitive operation
** Get stoma marked if possible
** Lower midline laparotomy      (some say LIF muscle-splitting incision is less morbid and just as easy)
** Hartmann's procedure if      systemically compromised (50% need it)
** Primary anastomosis if well      +/- covering ileostomy
** May require subtotal      colectomy if LBO is compromising proximal colon
* Non-resectional surgery
** Inferior - not recommended
** Percutaneous endoscopic      colostomy and percutaneous endoscopic sigmoidopexy are reserved for      selected non-operative candidates, having had multiple recurrences. High      incidence of complications.

[[Category:Colorectal]]