Overview
Definition:
Mesenteric volvulus is a surgical emergency characterized by the twisting of the mesentery, leading to obstruction of intestinal blood flow and potential bowel ischemia or infarction
It can be primary (congenital or idiopathic) or secondary (due to adhesions or tumors).
Epidemiology:
While rare, affecting approximately 0.04% of patients presenting with bowel obstruction, it accounts for a significant proportion of adult intestinal volvulus, particularly in certain geographic regions
Incidence peaks in the 3rd to 5th decades of life.
Clinical Significance:
Mesenteric volvulus is a life-threatening condition requiring prompt diagnosis and surgical intervention to prevent bowel necrosis, perforation, peritonitis, and sepsis
Early laparoscopic management can lead to improved outcomes and reduced morbidity compared to open surgery.
Clinical Presentation
Symptoms:
Sudden onset of severe, diffuse abdominal pain
Nausea and vomiting, often bilious
Abdominal distension
Constipation or obstipation
Passage of blood or mucus per rectum may occur if ischemia is advanced.
Signs:
Tenderness on abdominal palpation, which can be diffuse or localized
Guarding and rebound tenderness indicating peritonitis
Absent bowel sounds or high-pitched tinkling sounds
Signs of dehydration and hypovolemic shock in advanced cases.
Diagnostic Criteria:
There are no specific diagnostic criteria beyond clinical suspicion confirmed by imaging
The diagnosis relies on a high index of suspicion in patients with characteristic symptoms and findings confirmed by imaging modalities.
Diagnostic Approach
History Taking:
Focus on the acute onset of severe abdominal pain
Inquire about previous abdominal surgeries, history of constipation, or symptoms suggestive of a mass
Ask about any predisposing factors like abdominal adhesions or congenital malformations.
Physical Examination:
Perform a thorough abdominal examination, assessing for distension, tenderness, guarding, rebound tenderness, and bowel sounds
Evaluate for signs of dehydration and hemodynamic instability
Assess for hernias.
Investigations:
Plain abdominal X-rays may show dilated loops of bowel and air-fluid levels, often with an "inversely C-shaped" or "coffee bean" sign
Contrast-enhanced CT scan is the investigation of choice, revealing a dilated, twisted mesentery, a whirling pattern of mesenteric vessels (whirl sign), and signs of bowel ischemia (bowel wall thickening, mesenteric edema, pneumatosis intestinalis, portal venous gas)
Laboratory tests include CBC, electrolytes, renal function tests, and lactate levels.
Differential Diagnosis:
Other causes of acute intestinal obstruction such as adhesions, hernias, intussusception, malignancy, and inflammatory bowel disease should be considered
Differentiating volvulus from other causes of ischemic bowel, like mesenteric ischemia due to embolism or thrombosis, is crucial.
Management
Initial Management:
Immediate resuscitation is paramount, including intravenous fluid administration, electrolyte correction, nasogastric tube decompression, and broad-spectrum antibiotics
Pain management and monitoring of vital signs are essential.
Surgical Management:
Laparoscopic detorsion and fixation is the preferred initial surgical approach for confirmed mesenteric volvulus without signs of frank gangrene or perforation
The procedure involves untwisting the mesentery to restore blood flow
If bowel viability is questionable, a resection and anastomosis may be necessary, potentially requiring conversion to open surgery
Fixation of the mesentery may be considered to prevent recurrence.
Postoperative Care:
Close monitoring of vital signs, fluid balance, and abdominal distension
Gradual reintroduction of oral intake
Antibiotics may be continued
Close observation for signs of recurrent obstruction or ischemia
Early mobilization and prophylactic measures against deep vein thrombosis.
Supportive Care:
Nutritional support may be required for prolonged periods of ileus
Management of pain and nausea
Prevention of complications like pneumonia and urinary tract infections through diligent nursing care and early mobilization.
Complications
Early Complications:
Bowel necrosis and perforation, peritonitis, sepsis, intra-abdominal abscess, anastomotic leak if resection is performed, bleeding, prolonged ileus, and wound infection.
Late Complications:
Recurrent volvulus, adhesions leading to small bowel obstruction, incisional hernia if open surgery was performed, malnutrition, and psychological distress.
Prevention Strategies:
Prompt diagnosis and surgical intervention are the primary strategies
In cases of severe ischemia requiring resection, judicious use of bowel-sparing techniques and careful anastomosis can minimize complications
Consideration of fixation techniques during primary surgery may help reduce recurrence rates.
Prognosis
Factors Affecting Prognosis:
The viability of the bowel at the time of surgery is the most critical factor
Prompt diagnosis and intervention in the absence of significant ischemia lead to a much better prognosis
The extent of bowel resection and presence of comorbidities also influence outcomes.
Outcomes:
With timely laparoscopic detorsion and fixation in viable bowel, outcomes are generally good, with reduced hospital stay and faster recovery
For cases requiring resection, morbidity and mortality rates are higher, depending on the severity of ischemia and patient factors.
Follow Up:
Patients require close follow-up to monitor for signs of recurrent volvulus, adhesions, or other complications
Dietary advice and lifestyle modifications may be recommended
Patients with congenital anomalies might need long-term surveillance.
Key Points
Exam Focus:
Understand the etiology (primary vs
secondary), imaging findings (whirl sign on CT), and the critical role of prompt surgical management
Differentiate symptoms from other causes of acute abdomen
Emphasize the benefits of laparoscopic approach.
Clinical Pearls:
Always maintain a high index of suspicion for mesenteric volvulus in patients with sudden, severe abdominal pain and vomiting, especially if risk factors are present
Early CT scan is crucial for diagnosis
Laparoscopic detorsion should be attempted if feasible, but do not hesitate to convert to open surgery if bowel viability is uncertain or perforation is suspected.
Common Mistakes:
Delayed diagnosis due to attributing symptoms to less severe causes
Inadequate resuscitation before surgery
Attempting extensive bowel resection laparoscopically without adequate experience or if the patient is unstable
Failure to consider fixation in appropriate cases to prevent recurrence.