Sigmoid Volvulus Accounts for <10% of Intestinal Obstructions in the US
However, Sigmoid Volvulus is a More Common Etiology (Accounting for 50-80% of Cases) of Intestinal Obstruction in Other Parts of the World
Clinical Data
Incidence of Sigmoid Volvulus Has Remained Stable from 2002-2010 (Ann Surg, 2014) [MEDLINE]
In Contrast, the Incidence of Cecal Volvulus Has Increased Approximately 5.5% Per Year in this Period of Time (see Cecal Volvulus, [[Cecal Volvulus]])
Sigmoid Volvulus was More Common in Older Males >70 y/o, African-Americans, Patients with Diabetes Mellitus, and Patients with Neuropsychiatric Disorders
Cecal Volvulus was More Common in Younger Females (see Cecal Volvulus, [[Cecal Volvulus]])
Volvulus of the Gastrointestinal Tract May Occur in the Colon, Stomach, Gallbladder, and Small Intestine (see Gastric Volvulus, [[Gastric Volvulus]])
Colon is the Most Common Site of Volvulus
Cecum and Sigmoid Colon are the Most Common Sites of Colonic Volvulus (see Cecal Volvulus, [[Cecal Volvulus]])
Physiology
Twisting of Loop of Sigmoid Around its Mesentery
Obstruction of the Sigmoid Lumen and Impairment of Vascular Perfusion May Occur
“Ileosigmoid Knotting”: variant of sigmoid volvulus where the ileum is wrapped around the sigmoid (usually clockwise)
Etiologic Factors
Anatomic Factors
Long, Redundant Sigmoid Colon Due to Chronic Constipation
Chronic Constipation, with Fecal Overloading, May Result in Elongation and Dilation of the Sigmoid Colon (see Constipation, [[Constipation]]): may explain the increased incidence of sigmoid volvulus in older institutionalized adults
Colonic Dysmotility
Hirschsprung Disease (Congenital Aganglionic Megacolon) (see Hirschsprung Disease, [[Hirschsprung Disease]])
Sigmoid Volvulus May Be the Initial Presentation in Children with Hirschsprung’s Disease: aganglionic segment below the sigmoid colon and a mobile mesosigmoid may increase the risk of development of sigmoid volvulus
Prolonged Colonic Transit Due to Chronic Constipation (see Constipation, [[Constipation]])
May Be Useful Prior to CT Scan to Identify Pneumoperitoneum
When Pneumoperitoneum is Found, Surgery is Indicated and Further Imaging with CT Scan is Usually Not Necessary (see Pneumoperitoneum, [[Pneumoperitoneum]])
Upright KUB is Diagnostic in Only 60% of Cases of Sigmoid Volvulus
Findings
“Bent Inner Tube”: U-shaped distended (ahaustral) sigmoid colon which may extend from the pelvis to right upper quadrant
Vomiting Usually Occurs Several Days After the Onset of Abdominal Pain
Obstipation: absence of passage of stools or flatus
Hematologic Manifestations
Leukocytosis (see Leukocytosis, [[Leukocytosis]]): may occur in cases with sigmoid ischemia/infarction or perforation
Other Manifestations
Fever (see Fever, [[Fever]]): may occur in cases with sigmoid ischemia/infarction or perforation
Hypotension (see Hypotension, [[Hypotension]]): may occur in cases with sigmoid ischemia/infarction or perforation
Treatment
Colonoscopic or Sigmoidoscopic Detorsion (see Colonoscopy, [[Colonoscopy]])
Indications
Recommended Whenever Feasible
Technique
Allows Both Detorsion and Assessment of Colonic Viability
Following Colonoscopic Detorsion, Rectal Tube Can Be Left in Place with the Tip Beyond the Region of Torsion to Prevent Short-Term Recurrence of the Sigmoid Volvulus
Clinical Efficacy
Successful in 75-95% of Cases
Laparoscopy or Laparotomy (see Laparoscopy, [[Laparoscopy]] and Laparotomy, [[Laparotomy]])
Timing
Surgical Intervention May Be Performed 24-72 hrs After Colonoscopic Detorsion to Prevent Recurrence of Sigmoid Volvulus: this 24-72 hrs time delay allowed by prior colonoscopic detorsion allows time for adequate bowel preparation
However, it is Controversial as to Whether Surgery is Required in Cases of Successful Colonoscopic Detorsion, Since Approximately 40-50% of These Patients Will Not Have a Recurrence of the Sigmoid Volvulus (Am Surg, 1989) [MEDLINE]
Surgical Intervention is Required Immediately in Cases Where Colonoscopic Detorsion is Impossible/Unsuccessful or When Peritonitis is Present (see Peritonitis, [[Peritonitis]])
Technique
Sigmoid Resection with Primary Anastomosis or Hartmann’s Procedure
References
Sigmoid volvulus. A four-decade experience. Am Surg. 1989;55(1):41 [MEDLINE]
Colonic volvulus in the United States: trends, outcomes, and predictors of mortality. Ann Surg. 2014 Feb;259(2):293-301 [MEDLINE]