What are the guidelines for suture techniques in clinical trials, following International Conference on Harmonisation (ICH) guidelines?

ICH Guidelines for Suture Techniques in Clinical Trials

When conducting clinical trials involving sutures, a suture length-to-wound length ratio (SL/WL) of at least 4:1 should be used for continuous closure of incisions to reduce the risk of incisional hernia and wound complications. 1

Recommended Suture Techniques

Continuous vs. Interrupted Sutures

• Current evidence shows no significant difference between continuous or interrupted sutures for fascial closure in terms of incisional hernia or dehiscence rates
• However, continuous suture technique is preferred in clinical trials because it is faster and more efficient 1
• Continuous subcuticular suturing is the preferred technique for most wound closures, providing better cosmetic outcomes and more even tension distribution 2

Suture Material Selection

• Slowly absorbable sutures are recommended over rapidly absorbable sutures when using absorbable materials 1
• Monofilament sutures are preferred over multifilament sutures due to:
  • Lower infection risk
  • Less bacterial seeding
  • Lower resistance when passing through tissues 2, 3
• For facial wounds, 4-0 or 5-0 monofilament sutures are recommended 2

Technical Specifications

• Place stitches 5mm from the wound edge and 5mm apart 2
• Maintain a suture length-to-wound length ratio of at least 4:1 1, 2
• Use non-locking technique to avoid tissue edema and necrosis 2
• Small bite technique is suggested for midline laparotomy closure 1

Antibiotic-Impregnated Sutures

• High-quality RCTs support the use of antibiotic-impregnated sutures in clean, clean-contaminated, and contaminated fields to significantly reduce surgical site infections 1
• These should be used when available in emergency settings

Peritoneal Closure

• Separate closure of the peritoneum during abdominal wall closure is NOT recommended 1
• No short-term or long-term benefit has been demonstrated for peritoneal closure
• Avoiding peritoneal closure reduces operating time

Retention Sutures

• There is insufficient high-quality evidence to recommend routine use of retention sutures 1
• Consider retention sutures only in high-risk patients with:
  • Increased incision tension
  • Severe malnutrition
  • Immunocompromised status
  • Previous fascial defects
  • Massive abdominal contamination
• Note that retention sutures are associated with higher postoperative pain 1, 2

Suture Removal Timing

• For facial sutures, including high-mobility areas like the chin, remove after 5-7 days 2
• Early removal minimizes scarring while ensuring adequate wound healing
• Leaving non-absorbable sutures too long can lead to permanent suture marks, increased scarring, and higher infection risk 2

Documentation Requirements for Clinical Trials

• Document and verify the suture length-to-wound length ratio (SL/WL) at every wound closure 1
• Record the specific suture technique used (continuous vs. interrupted)
• Document the type of suture material used (absorbable vs. non-absorbable, monofilament vs. multifilament)

Common Pitfalls to Avoid

• Failure to maintain adequate SL/WL ratio of at least 4:1 1, 4
• Introducing bias by using different suturing techniques when comparing suture materials 4
• Using rapidly absorbable sutures for midline incisions 1
• Separate closure of the peritoneum, which increases operating time without benefit 1
• Excessive tension on sutures leading to tissue ischemia and poor wound healing 3
• Inappropriate suture size selection (use the smallest size that will accomplish the purpose) 3

Following these guidelines will help ensure standardized suturing techniques in clinical trials, reducing variability and improving the validity of research outcomes.