From the Guidelines
The muscle torn in a third-degree perineal laceration is the anal sphincter, specifically the internal anal sphincter (IAS) and possibly the external anal sphincter (EAS). This type of injury requires prompt and proper management to prevent long-term complications such as fecal incontinence, dyspareunia, and pelvic floor dysfunction.
Management of Third-Degree Perineal Laceration
The management of a third-degree perineal laceration involves a layered closure technique, starting with the repair of the torn anal sphincter using 2-0 or 3-0 PDS or Vicryl sutures in an end-to-end or overlapping technique, as recommended by 1.
- The internal anal sphincter (IAS) should be identified and reapproximated, as it is responsible for most of the anal sphincter resting tone, and its repair has been shown to improve 1-year anal incontinence rates 1.
- The rectal mucosa should be closed with continuous 3-0 or 4-0 Vicryl sutures.
- The vaginal mucosa should be repaired with continuous 2-0 or 3-0 Vicryl sutures.
- Finally, the perineal skin should be closed with interrupted or subcuticular 2-0 Vicryl sutures.
Postoperative Care
Postoperatively, patients should be prescribed stool softeners and laxatives to prevent constipation, and prophylactic antibiotics should be administered to prevent infection, as recommended by 1.
- Patients should be instructed on perineal hygiene, including sitz baths 2-3 times daily.
- Follow-up should occur at 2 weeks and 6-12 weeks postpartum to assess healing and evaluate for complications.
- Pelvic floor physical therapy is often beneficial for recovery, and patients should be encouraged to participate in this type of therapy to improve their outcomes.
Key Considerations
It is essential to prioritize the patient's comfort and pain management during the repair and postoperative period, using local cool packs, topical anesthetic sprays or ointments, and analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs, as recommended by 1.
- Opiates should be avoided if possible due to their potential complications.
- A Foley catheter should be placed before initiating the repair and remain in place until the patient is able to void adequately.
- The patient should be informed of the injury and the importance of close follow-up to ensure proper healing and prevent long-term complications.
From the Research
Third-Degree Perineal Laceration
A third-degree perineal laceration involves the anal sphincter complex, which includes the external and internal anal sphincter muscles.
- The external anal sphincter muscle is torn in a third-degree perineal laceration, specifically in 3b and 3c classifications, where 3b refers to a tear of more than 50% of the external anal sphincter thickness and 3c refers to an internal sphincter injury 2.
- The management of a third-degree perineal laceration typically requires immediate repair, with techniques including primary overlap or end-to-end repair of the external anal sphincter 2, 3.
Management of Third-Degree Perineal Laceration
The management of a third-degree perineal laceration involves:
- Immediate repair of the external anal sphincter, with primary overlap repair associated with a significantly lower incidence of fecal incontinence, urgency, and perineal pain compared to end-to-end repair 2.
- Postdelivery care focusing on controlling pain, preventing constipation, and monitoring for urinary retention, with the use of acetaminophen and nonsteroidal anti-inflammatory drugs as needed, and avoidance of opiates to decrease the risk of constipation 3.
- The use of osmotic laxatives to promote earlier bowel movements and reduce pain during the first bowel movement 3, 4.
- Consideration of transfer to an operating room for repair, especially for lacerations involving the anal sphincter complex, to ensure adequate expertise, exposure, and lighting 3.