A volvulus is the twisting of a segment of bowel on its mesentery, which results in bowel obstruction.
- 3rd most common cause of large bowel obstruction after cancer and diverticulitis
- Types of colonic volvulus:
- Sigmoid (80%; most common)
- Cecal (15%)
- Transverse colon (3%)
- Splenic flexure (2%)
- Sigmoid volvulus:
- Older men (mean age 70-years-old)
- Sometimes affects younger patients with colonic dysmotility
- Cecal volvulus: common in middle-aged women
- Long mesentery with a narrow base to allow twisting
- Redundant elongated colon usually from chronic constipation
- Risk factors:
- Age (50% of patients > 70-years-old)
- Institutionalized/nursing home residents
- Neurologic disorders (e.g., Parkinson’s disease, multiple sclerosis)
- Previous history of volvulus
- High-fiber diet
- Chronic constipation and laxative abuse
- Megacolon (Hirschsprung’s disease, Chagas disease)
- Usually congenital
- Incomplete dorsal mesenteric fixation of the cecum
- Elongated mesentery
- Torsion of bowel on its axis leads to closed-loop mechanical bowel obstruction.
- Accumulation of gas, water, and feces within the loop → increased intraluminal pressure
- Bacterial fermentation contributes to distention; increased intraluminal pressure impairs capillary perfusion.
- Impaired capillary perfusion of bowel → strangulation and ischemia
- Vascular occlusion in the mesentery if torsion is tight enough (> 360° torsion)
- Torsion of the mesenteric vascular pedicle → occlusion/thrombosis of mesenteric vessels → ischemia
- 3 types of cecal volvulus:
- Type 1: clockwise twisting of the cecum along the long axis (cecum in right lower quadrant)
- Type 2: counterclockwise twisting of the cecum and terminal ileum (cecum in left upper quadrant)
- Type 3: cecal bascule (upward folding of cecum rather than twisting)
- Onset is usually slow and insidious.
- Abdominal pain with gradual distention
- Constant pain with superimposed colicky episodes
- Nausea, constipation
- Typically vomiting a few days after the onset of pain
- Presentation is variable:
- Insidious onset of intermittent abdominal pain and cramping
- Acute sudden onset of abdominal pain
- Symptoms last from hours to days
- Severe, constant pain may indicate ischemia or perforation.
- Accompanying symptoms:
- Nausea and bilious vomiting
- Obstipation (inability to pass flatus or stool)
- Chronic constipation
- Long-term laxative use
- Neurologic disorders (e.g., Parkinson’s disease)
- Medications affecting bowel motility (psychotropics, opiates)
- Distended tympanitic abdomen
- Can be asymmetrically distended with emptiness on the right or left side
- Tenderness to palpation
- Signs of ischemia or perforation:
- Abdominal pain out of proportion to physical exam
- Peritoneal signs (guarding, rigidity, rebound tenderness)
- Hematochezia or blood on a digital rectal exam
- Complete blood cell count:
- Frequently normal
- Significant leukocytosis may indicate ischemia/perforation.
- Frequently normal
- Hypokalemia/metabolic alkalosis with protracted vomiting
- Metabolic acidosis/elevated lactic acid with ischemia/perforation
- Pregnancy test: obtained in all women of child-bearing age
- Upright abdominal X-ray:
- Sigmoid volvulus: coffee bean sign (dilated sigmoid colon projecting to the right upper quadrant)
- Cecal volvulus:
- Kidney bean sign (dilated colon loop extending from right side to mid-abdomen)
- Signs of small bowel obstruction (SBO): distended loops, air-fluid levels
- Pneumoperitoneum: indicates perforation
- Abdominal CT scan:
- Confirmatory test
- Whirl sign:
- Pathognomonic for volvulus
- Indicates twisting of the mesentery
- Small bowel dilatation (especially cecal volvulus)
- Significant colon dilatation with distal decompression and paucity of gas in the rectum
- Signs of ischemia:
- Pneumatosis intestinalis (air in the bowel wall) and portal venous gas
- Thickened bowel wall (due to loss of venous/lymphatic drainage)
- Free intraperitoneal fluid
- Mesenteric fat stranding
- Differential wall enhancements (poor uptake of intravenous (IV) contrast into the wall of the affected bowel)
- Free air indicates perforation.
- Contrast enema:
- Rarely needed for diagnosis
- Sigmoid volvulus:
- Bird’s beak sign is seen at the sigmoid.
- Dye does not pass the twist point in the sigmoid colon.
- Cecal volvulus: bird’s beak sign, dye does not enter the small bowel
Initial supportive management
- IV fluid and correction of electrolyte imbalance
- Nil per os (NPO)
- Nasogastric decompression if vomiting/signs of SBO
- IV antibiotics for suspected ischemia/perforation/signs of sepsis
Sigmoidoscopy with detorsion:
- For stable patients with no suspicion of ischemia or perforation
- Flexible or rigid
- Rectal tube should be left in place for decompression and prevention of immediate recurrence.
- Success rate: 75%–95%
- Recurrence: up to 84%
- Definitive surgery is recommended unless a very high surgical risk patient.
- Decompression should be attempted if feasible prior to surgery:
- Converts emergent surgery into elective surgery and allows preoperative planning
- Allows for successful primary anastomosis (helps avoid colostomy)
- Peritonitis, signs of ischemia/perforation
- Unsuccessful endoscopic detorsion
- Successful detorsion in patients who are acceptable surgical candidates
- Sigmoid colectomy with primary anastomosis: stable patients with viable colon
- Sigmoid colectomy with end colostomy (Hartmann’s procedure): unstable patients, perforation, ischemia
- Direct surgical intervention after stabilization
- Colonoscopic decompression increases the risk of perforation and is not performed.
- Hemodynamically stable patients: ileocecal resection or right colectomy with ileocolic anastomosis
- Unstable patients:
- Detorsion and cecopexy (for viable bowel) +/- cecostomy tube for decompression
- Right colectomy with ileostomy (for ischemic/necrotic bowel)
- Cecal volvulus: 6.64%
- Sigmoid volvulus: 9.44%
Predictors of mortality:
- Bowel gangrene/peritonitis
- Advanced age
- Chronic kidney disease
- Stoma creation during surgery
- Acute megacolon/colonic pseudo-obstruction: massive dilation of the entire colon secondary to a functional problem rather than a mechanical obstruction; usually diagnosed by a combination of clinical history and imaging. Treatment is typically medical management with surgery reserved for advanced cases associated with ischemia and sepsis.
- Toxic megacolon: a complication of infectious or inflammatory colitis. Presentation includes tachycardia, hypotension, and massive abdominal distention. Diagnosis is based on several symptoms such as a history of bloody diarrhea, fever/infection, and CT findings characteristic of toxic megacolon. Management depends on the underlying cause with surgery reserved for failure of medical management.
- Mechanical large bowel obstruction (LBO): interruption of the flow of contents through the colon. Presentation is similar to the clinical picture and X-ray findings (dilation of the colon) of sigmoid volvulus. Definitive diagnosis is established with a CT scan and sometimes colonoscopy. Management usually involves surgical resection to address the cause of the obstruction.
- Mechanical small bowel obstruction (SBO): interruption of the flow of contents through the small bowel. Presentation similar to the clinical picture and some X-ray findings (small bowel dilation) of cecal volvulus. A definitive diagnosis is established with a CT scan. Nonoperative management is frequently successful. Surgery is reserved for severe clinical presentation and failure of medical management.
- Halabi W.J., Jafari M.D., Kang C.Y., Nguyen V.Q., Carmichael J.C., Mills S., et al. (2014). Colonic volvulus in the United States: trends, outcomes, and predictors of mortality. Ann Surg.
- Hodin R.A. (2020). Cecal Volvulus. Retrieved February 15, 2021, from https://www.uptodate.com/contents/cecal-volvulus
- Hodin R.A. (2020). Sigmoid Volvulus. Retrieved February 15, 2021, from https://www.uptodate.com/contents/sigmoid-volvulus
- Thornton S.C. (2020). Sigmoid and Cecal Volvulus. Retrieved February 16, 2021, from https://emedicine.medscape.com/article/2048554-overview
- Williams N., Bulstrode Ch. (2013). Bailey and Love’s Short Practice of Surgery 26th ed. (pg 1181–1198).