What is the role of diagnostic laparoscopy (DL) in the diagnosis of chronic recurrent abdominal pain (CRAP)?

Diagnostic Laparoscopy in Chronic Recurrent Abdominal Pain

Diagnostic laparoscopy should be performed in patients with chronic recurrent abdominal pain when non-invasive investigations (CT, MRI, endoscopy) remain negative, as it achieves definitive diagnosis in 86-100% of cases and provides therapeutic benefit in 70-90% of patients with positive findings. 1, 2

Patient Selection Criteria

Proceed with Diagnostic Laparoscopy When:

• Duration of pain exceeds 12 weeks with negative or inconclusive imaging studies (CT scan, MRI) and negative upper endoscopy 3, 4
• Post-bariatric surgery patients (especially Roux-en-Y gastric bypass) with persistent pain require exploratory laparoscopy within 12-24 hours due to high risk of internal hernias, adhesions, and intussusception that may not appear on CT imaging 1, 4
• Prior abdominal surgery is present, as adhesions are found in 17-39% of cases and prior surgery is not a contraindication 2, 3, 5
• Average 3.3 diagnostic studies have been performed without establishing diagnosis 3

Critical Timing Considerations:

• Urgent laparoscopy (12-24 hours) is mandatory when vital sign abnormalities are present: tachycardia ≥110 bpm, fever ≥38°C, hypotension, tachypnea with hypoxia, or decreased urine output 1
• Delayed laparoscopy beyond 24 hours when acute pathology is suspected increases morbidity and mortality fourfold 1
• Routine cases should wait 2-6 weeks if recent acute inflammatory episode to allow resolution of inflammatory changes 6

Contraindications:

• Hemodynamically unstable patients requiring immediate laparotomy should not undergo diagnostic laparoscopy 1

Expected Diagnostic Yield and Findings

Diagnostic Success Rate:

• 86-100% diagnostic yield in establishing definitive diagnosis 1, 2
• 65-76% positive findings in unselected chronic pain populations 4, 7
• 57% positive findings specifically in post-bariatric surgery patients 4

Most Common Pathological Findings (in order of frequency):

1. Chronic appendicitis (19%) - appendectomy should be performed even if appendix appears macroscopically normal, as 19-40% harbor pathological inflammation 1, 2
2. Adhesions (17-39%) - most common in patients with prior abdominal surgery 2, 3, 5
3. Peritoneal tuberculosis (15.3%) 2
4. Internal hernias - particularly in post-bariatric patients 1, 4
5. Chronic cholecystitis 4
6. Endometriosis (3%) 3

Therapeutic Efficacy

Immediate Outcomes:

• 90% of patients report pain improvement or resolution at initial postoperative visit 3
• 46-56% undergo therapeutic intervention during the same laparoscopic procedure 2, 3

Long-Term Pain Relief:

• 71.4% maintain long-term pain relief at average 129-week follow-up 3
• 70% of patients with positive laparoscopic findings requiring intervention experience significant symptom improvement 4
• 89.3% remain pain-free at mean 75-week follow-up 5
• All pain recurrences occur within first 6 months - if pain-free at 6 months, long-term success is highly likely 3

Important Caveat:

• 43-57% of patients require long-term medical management despite laparoscopy, particularly those with negative findings 4, 7
• 73% report improvement even when no positive finding is made, suggesting diagnostic reassurance has therapeutic value 7

Surgical Technique Protocol

Systematic Exploration Sequence:

For post-bariatric patients, start from ileocecal junction and proceed proximally to inspect: 1

• Jejuno-jejunostomy
• Three potential internal hernia sites
• Remnant stomach

For general chronic pain, perform methodical inspection of entire abdomen including: 2

• All four quadrants
• Appendix and surrounding structures
• Gallbladder
• Pelvic organs
• All previous surgical sites

Intraoperative Decision-Making:

• Close mesenteric defects with non-absorbable suture if internal hernias found 1
• Assess intestinal viability and perform resection if ischemia present 1
• Use indocyanine green fluorescence angiography when available to assess bowel viability 1
• Perform appendectomy if no other pathology found and appendix appears normal, as microscopic inflammation is common 1

Safety Profile

Procedural Safety:

• No major complications reported in multiple series 2, 3, 5
• No conversions to laparotomy required in diagnostic series 3, 5
• Average operative time: 70 minutes 3
• 76% performed as outpatient procedures 3
• Safe in pregnant post-bariatric patients with good maternal and fetal outcomes 1

Reported Complications:

• Post-operative abscess formation (pelvic or abdominal wall) occurs rarely 4
• Overall complication rate remains very low across all studies 2, 3, 5, 7

Algorithmic Approach to Patient Selection

Step 1: Initial Evaluation

• Confirm pain duration >12 weeks 3
• Document negative CT scan, MRI/MRCP, and upper endoscopy 4
• Check inflammatory markers (CRP, ESR, fecal calprotectin) if inflammatory bowel disease suspected - diagnostic yield significantly higher when positive (66.7% vs 21.4%) 6, 1

Step 2: Risk Stratification

• High-risk/urgent: Post-bariatric surgery, vital sign abnormalities, pregnant post-bariatric → proceed to laparoscopy within 12-24 hours 1
• Standard risk: Chronic pain >12 weeks, prior abdominal surgery, negative workup → schedule elective diagnostic laparoscopy 3, 5

Step 3: Pre-operative Counseling

• Inform patients of 86-100% diagnostic yield 1, 2
• Explain 70-90% therapeutic success rate if positive findings 3, 4
• Discuss 43-57% chance of requiring ongoing medical management 4
• Emphasize safety profile with minimal complications 2, 3, 5

Step 4: Post-operative Follow-up

• Assess pain at initial visit (expect 90% improvement) 3
• Critical 6-month follow-up - all recurrences occur within this timeframe 3
• If pain-free at 6 months, long-term success highly likely 3

Common Pitfalls to Avoid

• Do not delay laparoscopy in post-bariatric patients with persistent pain and negative imaging - internal hernias frequently missed on CT 1, 4
• Do not assume normal-appearing appendix is normal - perform appendectomy if no other pathology found, as 19-40% harbor microscopic inflammation 1
• Do not exclude patients with prior abdominal surgery - adhesions are common and treatable cause of chronic pain 3, 5, 7
• Do not perform laparoscopy immediately after acute inflammatory episode - wait 2-6 weeks for resolution to improve visualization 6
• Do not proceed in hemodynamically unstable patients - these require immediate laparotomy 1