Overview
Definition:
Intraoperative enteroscopy (IOE) is a diagnostic and therapeutic endoscopic technique performed during laparotomy or laparoscopy to directly visualize and intervene in the small bowel
It is particularly useful for diagnosing and managing small bowel bleeding (SBB) when conventional methods fail to localize the source, representing a critical tool in surgical management of obscure gastrointestinal bleeding.
Epidemiology:
Obscure gastrointestinal bleeding (OGIB), of which SBB is a major component, accounts for approximately 5% of all GI bleeds
Patients with OGIB may present with overt bleeding (hematochezia or melena) or occult bleeding (iron deficiency anemia)
The incidence of SBB requiring intervention is lower, but it poses significant diagnostic and management challenges, impacting a substantial number of patients annually undergoing surgical evaluation for persistent or recurrent bleeding.
Clinical Significance:
Effective management of SBB is crucial as persistent bleeding can lead to severe anemia, hemodynamic instability, and a need for repeated transfusions, significantly impacting patient morbidity and mortality
IOE offers a direct approach to identify and treat lesions in the jejunum and ileum, which are difficult to access with standard upper and lower endoscopy, thus improving patient outcomes and reducing the need for extensive bowel resection when the bleeding source is precisely identified.
Indications
Absolute Indications:
Persistent or recurrent small bowel bleeding (overt or occult) despite negative upper endoscopy and colonoscopy
Hemodynamic instability due to unidentified SBB
Suspicion of small bowel malignancy with bleeding.
Relative Indications:
Need to confirm a suspected small bowel lesion identified by imaging (e.g., CTA, capsule endoscopy)
Planning for precise surgical resection of a known small bowel lesion
Evaluation of small bowel polyps or tumors.
Contraindications:
Uncorrected coagulopathy
Severe active systemic illness precluding surgery
Inability to achieve adequate bowel preparation (if feasible pre-operatively)
Significant adhesions or distorted anatomy making intestinal access difficult
Patient refusal or inability to consent.
Preoperative Preparation
Patient Assessment:
Thorough history and physical examination focusing on bleeding history, comorbidities, and prior abdominal surgeries
Assessment of hemodynamic status and need for resuscitation
Review of all previous investigations (endoscopy, imaging, capsule endoscopy).
Blood Product Management:
Ensure adequate blood availability for transfusion
Correction of coagulopathy with fresh frozen plasma, vitamin K, or platelet transfusion as indicated
Cross-matching for blood products.
Bowel Preparation:
Clear liquid diet for 24-48 hours preoperatively
Use of bowel cleansing agents (e.g., polyethylene glycol) if feasible, though often limited due to active bleeding
Nasogastric tube insertion for gastric decompression may be considered.
Anesthetic Considerations:
General anesthesia with adequate muscle relaxation
Careful fluid management
Consideration of jejunal intubation for decompression during IOE
Monitored by anesthesiology team throughout the procedure.
Procedure Steps
Access And Enteroscopy:
Laparotomy or laparoscopic approach to access the small bowel
Small bowel enterotomy is created, typically in the jejunum, to insert the enteroscope (single-balloon, double-balloon, or spiral enteroscope).
Diagnostic Enteroscopy:
The enteroscope is advanced distally through the small bowel lumen under direct visualization
Careful inspection of the entire visualized bowel circumference for bleeding sites, erosions, ulcers, polyps, tumors, or vascular malformations.
Therapeutic Intervention:
Once the bleeding source is identified, therapeutic interventions are performed
These include endoscopic clips, electrocoagulation (bipolar or monopolar), argon plasma coagulation, injection therapy (e.g., epinephrine, sclerosing agents), or band ligation.
Completion And Closure:
After successful intervention, the enteroscope is withdrawn
The enterotomy site is meticulously repaired with sutures or staples
A thorough inspection of the abdomen for hemostasis and absence of other complications is performed before closure.
Postoperative Care
Monitoring:
Close monitoring of vital signs for hemodynamic stability
Serial hemoglobin and hematocrit measurements
Assessment for signs of re-bleeding, abdominal distension, pain, or peritonitis
Intake and output monitoring.
Pain Management:
Adequate analgesia for incisional pain and bowel manipulation
Patient-controlled analgesia or epidural analgesia may be considered
Opioids should be used judiciously due to potential for ileus.
Nutritional Support:
Intravenous fluids for hydration and electrolyte balance
Gradual reintroduction of oral diet once bowel function returns, starting with clear liquids and advancing as tolerated
Parenteral nutrition may be necessary if prolonged ileus or significant resection occurs.
Antibiotic Prophylaxis:
Prophylactic antibiotics are generally administered perioperatively to cover common enteric flora, typically covering Gram-negative rods and anaerobes
Duration of antibiotics depends on the extent of surgery and patient factors.
Complications
Early Complications:
Bleeding from the enterotomy site
Perforation of the small bowel
Suture line dehiscence or leakage
Intra-abdominal abscess
Ileus
Pancreatitis (rare, related to manipulation).
Late Complications:
Stricture formation at the enterotomy site
Adhesions leading to bowel obstruction
Recurrent bleeding from an unidentified or incompletely treated lesion
Wound complications.
Prevention Strategies:
Meticulous surgical technique during enterotomy creation and closure
Careful enteroscope manipulation to avoid trauma
Appropriate patient selection and preoperative optimization
Prompt recognition and management of any intraoperative or postoperative issues.
Key Points
Exam Focus:
IOE is a crucial adjunct for obscure SBB
Indications, contraindications, and the sequence of therapeutic interventions are high-yield
Recognizing complications and their management is critical for DNB/NEET SS exams.
Clinical Pearls:
When performing IOE, good visualization is paramount
Consider jejunal intubation to facilitate balloon/spiral enteroscope advancement
Precise localization of the bleeding site allows for targeted therapy and avoids unnecessary bowel resection.
Common Mistakes:
Overlooking less common causes of SBB (e.g., Dieulafoy's lesion, GIST)
Inadequate bowel prep or visualization
Aggressive resection without definitive localization of bleeding source
Failure to anticipate and manage potential complications.