What is the best approach to treat small bowel intussusception in an adult?

Treatment of Small Bowel Intussusception in Adults

Surgery is the definitive treatment for small bowel intussusception in adults, with the decision to reduce before resection versus en bloc resection depending on the likelihood of malignancy and bowel viability. 1, 2

Initial Diagnostic Approach

Obtain CT imaging immediately as it is the most sensitive diagnostic modality for confirming intussusception and identifying lead point lesions. 2, 3, 4 CT can distinguish between intussusceptions with and without a structural cause, though determining malignancy versus benign edema remains challenging. 4

Key imaging findings to assess:

• Location (enteric vs ileocolic vs colonic) 1
• Presence of lead point lesion 2
• Bowel viability (though markers are imprecise) 4

Surgical Decision Algorithm

For Small Bowel (Enteric) Intussusception:

Reduction followed by limited resection is appropriate when:

• Benign etiology is strongly suspected preoperatively 3, 5
• The bowel segment appears viable 5
• Extensive resection would risk short bowel syndrome 2, 3

The malignancy rate in enteric intussusception is 22.5%, with metastatic carcinoma being the primary malignant cause rather than primary bowel cancer. 1 This lower malignancy rate and different tumor biology supports a more conservative approach with reduction.

Resection without reduction is mandatory when:

• Severe ischemic bowel is present 3
• Malignancy is suspected based on imaging or clinical presentation 5

Critical Distinction by Location:

The pooled malignancy rates differ substantially by anatomic location:

• Enteric (small bowel): 22.5% 1
• Ileocolic: 36.9% 1
• Colonic: 46.5% 1

For ileocolic intussusception, use a selective approach based on preoperative suspicion of malignancy, as this represents an intermediate risk category. 1

Operative Principles

Perform formal bowel resection with oncological principles (en bloc resection without reduction) whenever malignancy is suspected to avoid:

• Intraluminal tumor seeding 1
• Venous tumor dissemination 1
• Inadequate oncologic margins 2

Reduction can be attempted in confirmed benign small bowel cases to:

• Limit the extent of bowel resection 2
• Preserve bowel length and prevent short bowel syndrome 2, 3

Important Clinical Context

Adult intussusception differs fundamentally from pediatric cases:

• Only 8-20% are idiopathic without a lead point 2
• 80-92% have an identifiable organic lesion 2
• Secondary causes include inflammatory bowel disease, postoperative adhesions, Meckel's diverticulum, benign tumors, malignant lesions, and metastatic disease 2

Postoperative morbidity and mortality are significant, with pooled rates of 22.1% for complications and 5.2% for mortality. 1

Key Pitfalls to Avoid

• Do not attempt preoperative reduction when neoplasia is suspected, as this is contraindicated. 4
• Do not assume benign etiology without definitive preoperative evidence, particularly in ileocolic or colonic locations where malignancy rates exceed 35%. 1
• Do not treat transient, asymptomatic enteric intussusceptions discovered incidentally on imaging, as these may not require intervention. 4
• Do not delay surgery for persistent symptomatic intussusception, as this is the definitive treatment. 2