CASE: Repair of a 4th-degree perineal tear
A hospital midwife has just helped a mother deliver a 10 lb baby after 4 hours of vigorous pushing. No episiotomy incision was made. The midwife diagnosed a 4th-degree perineal tear. You are kindly asked by the nurse-in-charge to perform the repair to help the midwife and patient.
What steps should be on your 4th-degree repair surgical checklist?
These repairs are few and far between. A checklist may be prudent.
In birth units with an operative vaginal delivery and episiotomy rate of less than 10%, 3rd- and 4th-degree perineal lacerations occur infrequently. In some units, 4th-degree lacerations occur in less than 0.5% of vaginal births, and 3rd-degree lacerations occur in less than 3% of vaginal births.1,2 Given the infrequent occurrence of these lacerations, a locally developed surgical checklist may help to guide you and your obstetrician colleagues to the most effective repair of these lacerations.
Surgical checklists have been demonstrated to reduce variances and improve patient outcomes.1,2 Potential components of such a checklist are discussed in this editorial.
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Here is what I endorse
1. Identify the clinician(s) best suited to do the repair
To achieve optimal outcomes, it might be best if the most experienced obstetrician available in the hospital assists with or performs the repair.
2. Consider moving the patient from a labor and delivery room to an operating room
When surgical procedures are performed in a labor and delivery room, anesthesia support, lighting, appropriate equipment, surgical assistance, and exposure are often suboptimal. For many birth units, moving the patient from a labor and delivery room to an operating room may provide a better site for repair of the 4th-degree laceration.
3. Consider administering pre-repair prophylactic antibiotics
In one randomized trial, administration of a single dose of cefotetan or cefoxitin (1 g), compared with placebo, at the time of the repair resulted in significantly fewer postrepair perineal wound complications.3 Results of an observational study also revealed that exposure to antibiotics prior to repair, but not after the repair, was associated with a reduced wound complication rate.4
4. Obtain excellent exposure
Consider requiring a surgical technician and/or surgical assistant for all 4th-degree repairs. Place a vaginal pack to improve visualization of the perineal structures and prevent uterine blood from covering key anatomic landmarks. A Gelpie or Weitlander self-retaining retractor is very helpful in obtaining exposure, especially if a surgical assistant is not available.
5. Define the extent of the perineal laceration
Obstetricians are aware that occult injury to the rectal mucosa may occur.5 A digital rectal exam, with directed examination of the anterior rectal wall, is beneficial in identifying the extent of the rectal mucosal laceration.
Assessing injury to the external anal sphincter is helped by placing the index finger in the rectum and the thumb on the position where the external anal sphincter should be and using the two fingers to assess whether it is intact. In addition, visualization of a ruptured external anal sphincter and the separated muscle clearly identifies this lesion. Allis clamps may be used to find the ends of the ruptured anal sphincter since they retract into their capsule. A standardized sequence of inspection and palpation may improve the detection of 3rd- and 4th-degree tears.6
6. Identify the apex of the laceration
Start the repair of the rectal mucosa at least 1 cm above the apex of the laceration. My most common error in repairing a perineal laceration is not definitively identifying the apex of the laceration before beginning the repair. Applying judicious traction to the true apex of the laceration helps to clarify the anatomy and speed the repair.
7. Repair the rectal mucosa with a 4-0 suture on a tapered needle
Use a 4-0 suture with a tapered needle to repair the rectal mucosa. For the repair of a 3rd- or 4th-degree tear, most obstetricians use either a braided polyglactin suture (Vicryl) or a monofilament polydiaxanone suture (PDS).
8. Repair the internal anal sphincter with a 3-0 suture on a tapered needle
The internal rectal sphincter is a thin sheath that is dull white or white-gray. It is positioned just above the rectal serosa. The internal rectal sphincter is often retracted laterally and superiorly following a 4th-degree tear. It often can be identified at the apex of the tear. Colorectal physiologists and surgeons believe that an intact and functioning internal anal sphincter plays an important role in the maintenance of continence to stool and flatus.7,8