When is it safe to remove drains and wound vacuums (wound vacs) after abdominal large ventral hernia repair?

Timing of Drain and Wound VAC Removal After Abdominal Large Ventral Hernia Repair

Drains and wound vacuum devices should be removed as soon as possible after abdominal large ventral hernia repair, with drains typically being safe to remove when output is less than 30 mL/day of serous fluid and wound VACs when adequate granulation tissue has formed. 1

General Principles for Drain Removal

• Drains should be removed as early as possible postoperatively to reduce drainage time, length of hospital stay, and risk of infection 2, 1
• Prolonged drainage is associated with increased risk of surgical site infections and longer hospitalization 2, 3
• Routine prophylactic use of intra-abdominal surgical drains is generally discouraged in clean and clean-contaminated cases due to lack of evidence supporting their benefit 2

Specific Criteria for Drain Removal After Ventral Hernia Repair

• Remove drains when drainage is serous and daily output has decreased to less than 30-50 mL/24 hours 1, 3
• Evidence suggests that drain removal is safe when fluid drainage is less than 300 mL/24h compared to waiting for drainage less than 100 mL/24h 2, 1
• Drain duration, rather than the last daily drainage volume, significantly affects infection rates - drains kept longer than 21 days significantly increase infection risk 3
• For surgical drains after abdominal procedures, removal should not be delayed beyond 7-14 days even if output remains higher than target levels 2, 3

Wound VAC Removal Timing

• Wound VACs should be removed when adequate granulation tissue has formed over the surgical site 2
• For grade 4 open abdominal wounds (frozen abdomen), NPWT (negative pressure wound therapy) can be used until sufficient granulation tissue has formed to support split thickness skin grafting 2
• The use of a wound contact layer (e.g., non-adherent silicon layer) is recommended between the NPWT wound filler and the wound bed to prevent damage during dressing changes 2
• Wound VACs placed through subcutaneous tunnels should be removed as soon as possible, not surpassing 7-14 days of use 2

Algorithm for Drain and Wound VAC Removal Decision-Making

1. Daily assessment of drain output:

   • If output is less than 30-50 mL/day of serous fluid → remove drain 1, 4
   • If output remains high (>30-50 mL/day) but drain has been in place for >7-14 days → consider removal to reduce infection risk 2, 3

2. Wound VAC assessment:

   • Evaluate granulation tissue formation 2
   • When adequate granulation tissue covers the surgical site → remove wound VAC 2
   • If wound VAC has been in place >14 days → consider removal regardless of wound status to reduce infection risk 2

Special Considerations and Pitfalls

• Drain duration over 21 days significantly increases infection rate, with an increase of 76.2% in infection rate with each additional week of drain retention 3
• Early drain removal has been associated with improved quality of life without negative effects on clinical outcomes in other surgical procedures 5
• Late removal of drains correlates with more complications; however, this may be because persisting output predicts impending complications rather than the delay itself causing problems 6
• When there is persistent large volume drainage, patients should be counseled about the relative risks of early versus late drain removal 4
• Increased risk of surgical site infections is associated with prolonged drainage 2, 3

By following these evidence-based guidelines for drain and wound VAC removal after abdominal large ventral hernia repair, surgeons can optimize patient outcomes while minimizing complications related to prolonged drainage.