7.5 Episiotomy & Surgical Perineal Repair

Episiotomy: Midline vs. Mediolateral & Restrictive Practice

An episiotomy is a deliberate surgical incision of the perineum to enlarge the vulvar outlet. Historical arguments that routine episiotomy protects against severe pelvic floor relaxation, preserves urinary continence, or prevents neonatal cranial trauma have been thoroughly refuted by randomized trials.

Current Practice Guidelines

Both ACOG and ACNM strongly recommend against routine or liberal episiotomy. Restrictive use is reserved for specific clinical situations:

• Urgent need for expedited delivery due to severe, non-reassuring fetal heart rate tracings.
• Complicated operative vaginal delivery (forceps or vacuum extractor) where maternal soft tissue restricts instrument application.
• Shoulder dystocia requiring internal rotational maneuvers or posterior arm delivery where maternal soft tissue impedes access.

Midline vs. Mediolateral Episiotomy

Principles & Surgical Techniques of Perineal Repair

Pre-Repair Assessment & Analgesia

• Exposure & Illumination: Position the patient in lithotomy with adequate lighting. Cleanse the perineum with an antiseptic solution.
• Digital Rectal Examination (DRE): A systematic DRE must be performed prior to surgical repair on every patient with an obstetric tear to evaluate the tone of the external and internal sphincters and definitively rule out occult 3rd- or 4th-degree injuries.
• Analgesia: Local infiltration with 10 to 20 mL of 1% lidocaine without epinephrine (maximum safe dose: 4.5 mg/kg or approximately 300 mg [30 mL of 1%]). Infiltrate the apex of the vaginal tear, perineal musculature, and subcutaneous tissues. Alternatively, perform a pudendal nerve block or top up an existing epidural.
• Suture Material: Synthetic absorbable polyglactin 910 (Vicryl) is the gold standard suture material. Compared to chromic catgut, polyglactin 910 is associated with significantly lower tissue inflammation, reduced short-term perineal pain, lower analgesic requirements, and reduced rates of wound dehiscence.

Stepwise Repair of a Second-Degree Laceration

1. Anchoring Apex Suture: Place the initial suture approximately 1 cm proximal (cephalad) to the apex of the vaginal mucosal laceration to ligate retracted mucosal and submucosal vessels.
2. Vaginal Mucosa Closure: Close the vaginal mucosa and submucosa using a continuous running (locking or non-locking) 2-0 or 3-0 polyglactin suture down to the level of the hymenal ring.
3. Hymenal Reapproximation: Bring the suture behind the hymenal caruncles, ensuring accurate alignment of the hymenal ring without excessive tension.
4. Perineal Musculature Reapproximation: Approximate the deep and superficial perineal muscles (bulbospongiosus and transverse perineal muscles) using continuous or interrupted figure-of-eight sutures. Rebuilding this muscular layer restores the anatomical height, thickness, and support of the perineal body.
5. Subcuticular Skin Closure: Close the perineal skin with a continuous subcuticular 3-0 or 4-0 absorbable suture starting at the inferior border near the anus and running upward to the introitus, burying the final knot deep within the vaginal mucosa.

Repair of Third- and Fourth-Degree Lacerations (OASIS Management)

Repairs of OASIS should be performed by experienced clinicians in an environment with optimal lighting, instrumentation, and adequate regional or general anesthesia:

1. Rectal Mucosa (4th-Degree): Close the anal submucosa and rectal mucosa with fine 3-0 or 4-0 absorbable sutures (Vicryl or PDS). Sutures may be placed continuously or interrupted, utilizing a submucosal technique that avoids piercing the rectal mucosa into the anal lumen.
2. Internal Anal Sphincter (IAS): Explicitly identify the glistening, pale fibrous smooth muscle ends of the IAS. Reapproximate the IAS separately using interrupted 3-0 absorbable sutures (end-to-end). Failure to identify and repair the IAS is the leading cause of persistent flatus and fecal incontinence following OASIS.
3. External Anal Sphincter (EAS): Grasp the retracted, striated muscle ends of the EAS with Allis clamps. The EAS can be repaired using either:
   • End-to-End Technique: Approximate the severed ends with 2 to 3 interrupted horizontal mattress or figure-of-eight 2-0 or 3-0 Vicryl/PDS sutures.
   • Overlapping Technique: Recommended for complete full-thickness EAS tears (Grade 3b, 3c, or 4th-degree), overlapping the muscle ends by 1 cm and securing with mattress sutures.
4. Vagina, Muscle, and Skin: Close the perineal body musculature, vaginal mucosa, and skin as in a second-degree repair.
5. Post-Repair Evaluation: Perform a repeat digital rectal examination to confirm intact sphincter tone, anatomical symmetry, and ensure that no through-and-through sutures penetrate the rectal mucosa.

Postoperative OASIS Care Bundle

• Prophylactic Antibiotics: Administer a single dose of broad-spectrum intravenous antibiotic at the time of repair (Cefotetan 1–2 g IV or Cefoxitin 2 g IV; or clindamycin/gentamicin in severe penicillin allergy) to significantly reduce wound infection and breakdown.
• Bowel Regimen: Prescribe daily stool softeners (docusate sodium 100 mg twice daily) and high-fiber supplements for 2 to 4 weeks to avoid hard stool and straining. Avoid mineral oil or strong stimulant laxatives.
• STRICT PROHIBITION: Nothing per rectum (NPO per rectum). Absolute avoidance of rectal examinations, rectal suppositories, and enemas during the recovery period.
• Pelvic Floor Physical Therapy: Schedule follow-up urogynecologic evaluation at 6 to 12 weeks postpartum.