What are the recommended suturing techniques for small‑bowel and colonic injuries, including suture material, number of layers, and indications for stapling or reinforcement?

Bowel Suturing Techniques

For small bowel injuries, primary repair is strongly preferred using either handsewn or stapled techniques, as both demonstrate equivalent safety profiles with minimal leak rates; for colonic injuries, the choice between handsewn versus stapled anastomosis should be guided by patient physiology and bowel edema, with handsewn techniques potentially safer in hemodynamically unstable trauma patients. 1

Small Bowel Repair Technique

Primary Approach

• Primary repair of small bowel injuries is the preferred method when technically feasible (GRADE: High recommendation). 1
• Small bowel demonstrates remarkable resilience with no reported leaks after 254 resections and anastomoses regardless of technique used. 1
• For traumatic perforations, rapid closure using gastrointestinal stapling devices is safe and effective, avoiding the need for formal resection when luminal compromise can be prevented. 2

Suture Material Selection

• Monofilament absorbable sutures with delayed resorption are optimal, specifically Polyglactin (Vicryl) or Polydioxanone (PDS). 3
• Polydioxanone retains adequate tensile strength throughout the critical 30-day healing period and produces minimal inflammatory response. 4
• Avoid braided materials (particularly silk) as they produce prolonged tissue response and harbor bacteria. 4

Layer Technique

• Single-layer seromuscular-extramucosal technique is equivalent to two-layer closure for small bowel. 1, 5
• If using two layers: inner mucomucosal layer with inversion, followed by outer seroserosal layer. 3
• For anastomoses, inverting technique is significantly more secure than everting technique. 5

Colonic Repair Technique

Patient Selection for Primary Anastomosis

• Primary anastomosis is safe only in carefully selected patients based on:
  • Hemodynamic stability (no ongoing transfusion or inotropic requirements) 1
  • Absence of significant bowel wall edema from reperfusion injury 1
  • Minimal peritoneal contamination 1
  • Patient's ability to tolerate potential anastomotic leak 1

Handsewn vs. Stapled Decision Algorithm

Use handsewn technique when:

• Patient has ongoing hemodynamic instability or significant bowel edema (Western Trauma Association data shows 4% leak rate with staples vs. 0% with handsewn in trauma patients, p=0.04). 1
• Performing anastomosis in damage control surgery setting 1
• Bowel demonstrates significant edema from splanchnic hypoperfusion and reperfusion 1

Stapled technique is acceptable when:

• Patient is hemodynamically stable with normal physiology 1
• Bowel is not significantly edematous 1
• Multi-center data in penetrating colonic injury shows equivalent leak rates (6.3% stapled vs. 7.8% handsewn, p=0.69). 1

Layer Technique for Colon

• Two-layer inverting technique remains standard for colonic anastomoses with peritoneal coat on both stumps. 5
• For low anterior resections where distal stump lacks peritoneal coat, one-layer end-on slightly inverting technique shows significantly fewer dehiscences. 5
• Ensure tension-free transverse repair after complete debridement of devitalized tissue. 6, 7

Special Considerations in Damage Control Surgery

Timing Considerations

• Avoid anastomosis during initial damage control laparotomy—rapidly staple or suture bowel ends closed instead. 1
• Delayed primary anastomosis at relook laparotomy carries increased but acceptable leak rates when abdomen can be closed. 1
• Risk of leak increases significantly when:
  • Anastomosis performed >48 hours after initial injury 1
  • Ongoing transfusion or inotropic requirements present 1
  • Abdominal fascial closure cannot be achieved 1
  • Tissue edema persists 1

Stoma Indications

• Diverting stomas are strongly recommended for high-risk patients with high-risk anastomoses (GRADE: Moderate). 1
• Loop stomas preferred over end stomas due to easier reversal and lower morbidity. 1
• End stomas and Hartmann's procedures remain safest option for patients at high risk for leak-related morbidity. 1

Critical Technical Pitfalls to Avoid

Duodenal-Specific Considerations

• Perform tension-free transverse repair with complete exposure and removal of all devitalized tissue. 6, 7
• Place nasogastric tube for proximal decompression. 6, 7
• Avoid routine periduodenal drain placement unless required for associated injuries (drains correlate with increased leak rates). 6, 7
• Do not use duodenal diverticulization, triple tube decompression, or routine pyloric exclusion—these are no longer advocated. 6

General Principles

• Ensure adequate tissue inversion and suture placement in healthy tissue—this is more important than mucosal inversion or multiple layers. 3
• Avoid incorporating omental patches directly into sutures; they should be placed variably for reinforcement only. 3
• For luminal size discrepancies, terminolateral anastomosis is the optimal choice. 3

Emerging Techniques

• Barbed suture demonstrates feasibility for bladder and bowel repair with no major complications in series of 20 bowel injuries (75% rectal, 15% colon, 10% small intestine), though this remains investigational. 8
• Most repairs (75%) used two layers of barbed suture for full-thickness defects. 8