What are the steps to perform an incision and drainage (I&D) procedure?

How to Perform Incision and Drainage (I&D)

Incision and drainage is the definitive treatment for abscesses, requiring complete evacuation of purulent material with the incision placed as close as possible to the skin surface while ensuring adequate drainage. 1, 2

Pre-Procedure Assessment

Clinical Evaluation

• Assess for sepsis, immunosuppression, diabetes, or diffuse cellulitis - these require emergency drainage 1, 2
• Determine timing: Emergency drainage if septic/immunocompromised; otherwise perform within 24 hours 1, 2
• Consider point-of-care ultrasound to accurately measure abscess size and depth, identify surrounding vascular structures, and distinguish abscess from cellulitis - this changes management in 55% of cases 3

Imaging Considerations

• Clinical diagnosis alone is usually sufficient for typical superficial abscesses 2
• Consider imaging for: atypical presentations, suspected deep abscesses (intersphincteric, supralevator), or suspected Crohn's disease 1, 2
• Ultrasound is preferred for superficial abscesses - it's fast, accurate, and changes procedural approach in over half of cases 3

Anesthesia Technique

Standard Approach

• Small simple abscesses can be drained under local anesthesia in the outpatient setting 1
• Avoid multiple painful infiltrations around the abscess 4

Alternative Aspiration-Injection Technique (for sacrococcygeal/pilonidal abscesses)

• Aspirate abscess contents first with needle 4
• Inject the same volume of local anesthetic directly into the abscess cavity through the same needle 4
• This eliminates multiple infiltrations and significantly reduces pain 4

Incision Technique

Incision Placement

• Make the incision as close as possible to the skin surface to minimize potential fistula tract length if one develops 1, 2
• For perianal abscesses: Keep incision close to anal verge while avoiding sphincter damage 1, 2
• Ensure adequate length to allow complete drainage and prevent premature skin closure 5

Location-Specific Approaches

• Perianal and ischioanal abscesses: Drain through overlying skin 1, 2
• Intersphincteric abscesses: Drain into rectal lumen (may require limited internal sphincterotomy) 1, 2
• Supralevator abscesses: Drain via rectal lumen if extension of intersphincteric abscess, or externally via skin if extension of ischioanal abscess 1

Drainage Procedure

Complete Evacuation

• Break up all loculations with finger or instrument - inadequate drainage is the primary cause of 15-44% recurrence rates 1, 2, 6
• Gently curette the cavity to ensure complete evacuation 4
• Send purulent material for culture to guide antibiotic therapy if needed 6

Packing Controversy

• Packing is NOT necessary and should be avoided - evidence shows it causes additional pain without improving healing time 5, 6
• If packing is placed, remove within 24 hours 5, 6
• Alternative: Consider high-vacuum wound drainage system, which reduces pain and treatment time compared to traditional packing 7

Management of Concomitant Fistulas

• If obvious fistula is identified during drainage: Perform fistulotomy ONLY for low fistulas not involving sphincter muscle 2
• For fistulas involving sphincter muscle: Place loose draining seton 2

Post-Procedure Care

Wound Management

• Allow wound to heal by secondary intention - do not allow premature skin closure 5
• Begin warm water soaks or sitz baths 24-48 hours post-procedure to promote drainage and healing 5
• Keep wound clean and dry initially 5

Antibiotic Therapy

• Antibiotics are NOT routinely indicated after adequate drainage 2, 5
• Prescribe antibiotics ONLY if: fever >38.5°C, sepsis, surrounding cellulitis, immunosuppression, or diabetes 2, 5

Follow-Up

• Routine imaging is NOT required after successful drainage 1, 2, 5
• Consider imaging for: recurrence, suspected inflammatory bowel disease, non-healing wounds, or suspected fistula 1, 2

Critical Pitfalls to Avoid

• Incomplete drainage is the #1 cause of recurrence (up to 44%) - ensure all loculations are broken up 1, 2, 6
• Needle aspiration alone has 41% recurrence vs 15% with I&D - aspiration is inadequate as definitive treatment 1
• Delayed drainage increases recurrence risk - time from onset to incision is a significant risk factor 1, 2
• Horseshoe-type abscesses and multiloculated collections require particularly thorough drainage 1, 2

Warning Signs Requiring Return

• Fever >38.5°C 5
• Rapidly spreading erythema 5
• Increasing pain, swelling, or purulent drainage after initial improvement 5