What size suture is recommended for a 3a perineal laceration (third-degree perineal laceration)?

Suture Size for 3a Perineal Laceration

For a 3a perineal laceration (third-degree tear involving less than 50% of the external anal sphincter), use 3-0 delayed absorbable suture for repair of both the internal and external anal sphincter components. 1

Suture Material and Size Specifications

Internal Anal Sphincter (IAS)

• Use 3-0 delayed absorbable suture (polyglactin or poliglecaprone) with an end-to-end technique using either mattress or interrupted sutures 1
• The IAS must be identified separately as it is thin, pale pink, and extends approximately 1.2 cm cephalad from the proximal margin of the external anal sphincter 1
• Repairing the IAS improves 1-year anal incontinence rates 2

External Anal Sphincter (EAS)

• Use 3-0 delayed absorbable suture for the external anal sphincter repair 1
• Either end-to-end or overlapping technique can be used, though overlapping repair shows lower fecal urgency and better anal incontinence scores at 1 year 1

Anorectal Mucosa (if involved)

• Use 3-0 or 4-0 delayed absorbable sutures (polyglactin or poliglecaprone) with either interrupted or continuous non-locked technique 1, 2

Preferred Suture Materials

Monofilament absorbable sutures are preferred over multifilament (braided) sutures because they cause less bacterial seeding and reduce infection risk 3

Recommended options include:

• Poliglecaprone (MONOCRYL) - provides excellent handling properties and minimal tissue resistance 4
• Polyglactin 910 (VICRYL) - acceptable alternative 1
• Polyglyconate (Maxon) - provides good tensile strength 1

Critical Technical Points

Suturing Technique

• Use continuous non-locking sutures to distribute tension evenly and reduce pain during healing 1, 3
• Locked sutures create excessive tension that can cause tissue necrosis and should be avoided 2

Sequential Repair Order

Repair must proceed from deep to superficial structures 1, 2:

1. Anorectal mucosa (if torn)
2. Internal anal sphincter
3. External anal sphincter
4. Rectovaginal fascia
5. Perineal body
6. Perineal skin
7. Vaginal muscularis and epithelium

Common Pitfalls to Avoid

• Failure to identify and repair the IAS separately leads to persistent anal incontinence 2
• Using locked sutures creates excessive tension causing tissue necrosis 2
• Inadequate anesthesia - regional or general anesthesia is mandatory for adequate muscle relaxation and proper repair 2
• Omitting prophylactic antibiotics increases wound infection risk by 300% (from 8.2% to 24.1%) 1, 2

Preoperative Requirements

• Administer prophylactic antibiotics (second- or third-generation cephalosporin, or metronidazole with gentamicin/clindamycin for penicillin allergy) before repair 1
• Perform vaginal preparation with povidone-iodine or chlorhexidine 1, 2
• Place Foley catheter before initiating repair 2
• Ensure adequate lighting and visualization in operating room setting 2