Overview
Definition:
Internal hernia at jejunojejunostomy refers to the entrapment of small bowel loops within a mesenteric defect created during a side-to-side jejunojejunostomy, often performed in bariatric or other gastrointestinal surgeries
These defects can lead to bowel obstruction or strangulation.
Epidemiology:
The incidence of internal hernias after jejunojejunostomy varies widely, reported from 1% to over 10% depending on the surgical technique, definition, and follow-up period
It is a significant cause of late small bowel obstruction in patients who have undergone Roux-en-Y gastric bypass.
Clinical Significance:
Internal hernias at jejunojejunostomy are a major cause of morbidity and mortality following specific gastrointestinal procedures
Early recognition and prompt surgical intervention are crucial to prevent complications like bowel ischemia, infarction, and perforation, which can be life-threatening.
Clinical Presentation
Symptoms:
Intermittent or persistent abdominal pain, often colicky
Nausea and vomiting, which may be progressive
Abdominal distension
Constipation or obstipation
Inability to tolerate oral intake
Signs of peritonitis (if strangulation or perforation has occurred).
Signs:
Tenderness on abdominal palpation, which may be localized or diffuse
Guarding and rebound tenderness if peritonitis is present
Distended abdomen
Visible peristalsis may be increased or absent
Signs of hypovolemic shock (if strangulation and hemorrhage occur).
Diagnostic Criteria:
No specific established diagnostic criteria exist
Diagnosis is primarily based on a high index of suspicion in patients with relevant surgical history presenting with symptoms of bowel obstruction, confirmed by imaging findings suggestive of internal herniation into a mesenteric defect.
Diagnostic Approach
History Taking:
Detailed surgical history is paramount, including type of surgery (e.g., Roux-en-Y gastric bypass, jejunal interposition), date of surgery, and any previous abdominal surgeries
A thorough review of current symptoms, onset, and progression is essential
Red flags include sudden onset of severe abdominal pain, intractable vomiting, and obstipation.
Physical Examination:
A complete abdominal examination focusing on signs of obstruction and peritonitis
Assess for tenderness, rigidity, distension, and bowel sounds
Digital rectal examination may reveal impacted stool in cases of distal obstruction, but is less helpful for proximal small bowel issues.
Investigations:
Abdominal X-ray: May show dilated loops of small bowel with air-fluid levels, and paucity of gas distally
however, it is often non-specific
CT scan of the abdomen with intravenous and oral contrast: This is the investigation of choice
It can identify the location of the herniated bowel, the mesenteric defect, associated signs of ischemia (bowel wall thickening, mesenteric stranding, venous engorgement), and the effaced mesenteric fat of the defect
MRI: May be useful in select cases or when CT is contraindicated
Laboratory tests: Complete blood count (leukocytosis), electrolytes, renal function tests, liver function tests, and lactate (elevated in ischemia).
Differential Diagnosis:
Other causes of small bowel obstruction (adhesions, intussusception, external hernias)
Mesenteric ischemia from other causes
Pancreatitis
Appendicitis
Diverticulitis
Bowel perforation from other etiologies.
Surgical Management
Indications:
Confirmed internal hernia on imaging
Suspected internal hernia with signs of bowel obstruction or strangulation
Persistent symptoms not responding to conservative management.
Procedure Steps:
Laparoscopic or open exploration of the abdomen
Identification of the jejunojejunostomy and associated mesenteric defect
Careful reduction of the herniated bowel loops
Careful assessment of bowel viability
resection of compromised bowel if necessary
Closure of the mesenteric defect is the critical step
Multiple techniques exist, and the choice depends on the anatomy of the defect and surgeon preference.
Closure Techniques:
Direct suture closure of the mesenteric defect using non-absorbable or slowly absorbable sutures
Techniques aim to obliterate the defect without constricting the bowel
Examples include simple interrupted sutures approximating the mesenteric edges, or more elaborate techniques to create a mesenteric sling
In some cases, if the defect is large or recurrent, tacking of the jejunal limbs to the anterior abdominal wall or peritoneum may be considered, though this carries its own risks
A thorough assessment of the defect and its relation to the afferent and efferent limbs is vital
The goal is to prevent re-herniation while ensuring adequate blood supply to the bowel loops.
Postoperative Care:
Nil per os (NPO) status
Nasogastric tube decompression
Intravenous fluids and electrolyte correction
Analgesia
Close monitoring for signs of anastomotic leak, infection, or recurrent obstruction
Gradual reintroduction of oral diet once bowel function returns
Antibiotics if peritonitis or bowel resection was performed.
Complications
Early Complications:
Bowel ischemia or infarction requiring resection
Anastomotic leak
Bleeding
Infection (wound infection, intra-abdominal abscess)
Recurrent internal hernia immediately post-operatively.
Late Complications:
Recurrent internal hernia
Adhesions leading to further bowel obstruction
Stricture at the site of anastomosis or defect closure
Chronic abdominal pain
Malabsorption syndromes (rare).
Prevention Strategies:
Meticulous surgical technique during the primary procedure to minimize the size of mesenteric defects
Secure closure of all iatrogenic mesenteric defects
Careful technique during jejunojejunostomy creation
Patient education regarding symptoms of internal hernia and when to seek medical attention
In bariatric surgery, closing mesenteric defects at the gastrojejunostomy and jejunojejunostomy sites is standard practice
Careful assessment of any residual defects
Consider prophylactic closure even of small defects if they appear precarious or have sharp edges that could entrap bowel.
Key Points
Exam Focus:
Internal hernias at jejunojejunostomy are a common cause of post-operative obstruction in bariatric surgery
CT scan is the gold standard for diagnosis
Prompt surgical exploration and closure of the mesenteric defect are essential
Recurrence is a significant concern.
Clinical Pearls:
Always consider internal hernia in patients with prior abdominal surgery presenting with unexplained abdominal pain and vomiting, especially after bariatric procedures
Be meticulous with mesenteric defect closure during primary surgery
Thorough assessment of bowel viability is crucial during exploration for strangulation.
Common Mistakes:
Delaying surgical intervention due to non-specific symptoms
Inadequate exploration leading to missed defects
Incomplete or incorrect closure of the mesenteric defect, leading to recurrence
Failing to identify signs of bowel ischemia
Over-reliance on plain X-rays without CT confirmation.