Deep vaginal tears
- Lacerations involving the middle or upper third of the vaginal vault are usually accompanied by injuries to the perineum or cervix and are sometimes missed without a thorough inspection
- Should prompt you to inspect for cervical lacerations, peritoneal perforation and retroperitoneal hemorrhage
- Tears extending upward are usually longitudinal
- More common in operative vaginal delivery
- Often involve deeper underlying tissues and can therefore cause more significant bleeding, which is controlled by suture repair
- Repair requires adequate analgesia, visualization, assistance, and resuscitation if hypovolemia is present
Anterior and peri-urethral tears
- Small tears of the anterior vaginal wall near the urethra are common
- They are often superficial with little or no bleeding, and therefore don’t require sutures and will heal by secondary intention
- If they require sutures for hemostasis, try to minimize the number of sutures and take small bites with care to avoid the clitoris and urethra
- If they require extensive repair, they are often associated with short-term voiding difficulties and it is helpful to insert an indwelling bladder catheter
- Insertion of an indwelling bladder catheter can also help prevent urethral injury during repair and prevent post-repair urinary retention from tissue edema
- Graded based on depth
- Third and fourth degree tears are higher-order and require more extensive repairs to decrease the associated higher risk of morbidity
- Higher order tears (grade 3 and 4) are also known as Obstetrical Anal Sphincter Injuries (OASIS)
- Combined incidence 0.5-5%
- Mediolateral episiotomy is protective in most, but not all studies
- Blood loss
- Puerperal pain
- Wound disruption and infection
- Doubled risk of fecal incontinence compared to 1st and 2nd degree lacs
Third degree tears
- Involves the anal sphincter
- 3a: <50% of the external anal sphincter (EAS) is torn
- 3b: >50% of the EAS is torn, but the internal anal sphincter (IAS) remains intact
- 3c: EAS and IAS are torn, but rectal mucosa is intact
Repair of third degree tears
- Two methods exist to repair the external anal sphincter (EAS):
- End-to-end technique
- Cut ends of the EAS are isolated and brought to the midline end-to-end
- Overlapping technique
- Cut ends of the EAS are brought to the midline and lie atop one another
- Only suitable for type 3C lacerations (the EAS is completely lacerated)
- The strength of the closure comes from the connective tissue of the capsule, and not the striated muscle.
- The ends of the EAS are often grasped and manipulated gently with Allis clamps.
- There is no evidence to support one technique over the other in a 3C laceration repair.
Repair of third degree tears: End-to-end technique
- Isolate the cut ends of the EAS and bring them to the midline (these are often retracted and found more laterally than expected)
- Place 4-6 simple interrupted sutures at 3, 6, 9 and 12 o’clock positions and then a figure-of-eight suture in the middle to re-appose the sphincter muscle fibers
- OR place 4 figure-of-eight sutures at 3, 6, 9 and 12 o’clock positions incorporating both the muscle and fascia
- Be sure to incorporate both the sphincter fibers and peri-sphincter connective tissue
- Start with posterior suture to maintain exposure, followed by inferior and superior and then lastly the anterior suture
Repair of third degree tears: Overlapping technique
- If the internal anal sphincter (IAS) is lacerated, it is first re-approximated with a continuous, non-locking suture starting proximal to the apex (using delayed absorbable suture)
- Next, the cut ends of the EAS are isolated (often involving further dissection) and brought to the midline to lie atop one another
- Two rows of mattress sutures travel through both sphincter ends to recreate the anal ring
Note: The IAS is identified as the glistening white fibrous structure lying between the anal canal submucosa and the fibers of the EAS (this layer also retracts laterally and must be found and brought to midline).
Fourth degree tears
- Involves the perineal body, entire anal sphincter complex, and anorectal mucosa
Repair of fourth degree tears
- Re-approximate the anal mucosa
- Begin at the apex of the tear
- Use an interrupted 3-0 Vicryl suture with knots tied in the anal lumen or external to the anal canal (see SOGC guidelines)
- Alternatively, 3-0 PDS in a running submucosal suture can be used to close the mucosa
- Do not use figure-of-eight sutures, as they can cause ischemia and poor healing of mucosa
- Next, identify and repair the internal anal sphincter
- The IAS lies between the EAS and anal mucosa and has a thin, pale pink appearance in close proximity to the anal mucosa, which may be similar to a “fascial” layer. Proper identification of the IAS and separate repair improves continence at 1 year!
- Using 2-0 Vicryl, reapproximate the IAS using simple interrupted sutures in an end-to-end fashion.
- The EAS can then be repaired using either the end-to-end or overlapping technique (there is no evidence to support one technique over the other)
- Identify the ends of the EAS, which often retract under tonic contraction, and can be found postero-laterally to the tear.
- Grasp the ends with Allis clamps and mobilize the sphincter with Metzenbaum scissors and dissection, if needed
- With an end-to-end repair, use 2-3 mattress sutures to re-approximate the ends, being sure to include the fascial sheath.
- With an overlapping repair, the EAS muscles require more dissection, using the ischioanal fat laterally as a landmark. The full length of the torn ends of the EAS are overlapped in a double-breasted fashion.
- Then, suture the perineal body.
- Repair the vaginal mucosa and perineal skin in the usual fashion.
- Confirm adequacy of the repair with a DRE.
For a demonstration of a fourth degree perineal tear repair, please see this video by UpToDate in Obstetrics & Gynecology.
- Common in more than half of vaginal deliveries, but usually small and do not require repair
- Problematic when they bleed heavily or extend into the vagina
- Have assistant apply firm downward pressure on the uterus
- Apply gentle traction on the lips of the cervix with ring forceps
- Lacerations < 2 cm often don’t need repair unless actively bleeding
- Deep lacerations usually require repair
- Place first suture above the angle or apex of the laceration to tamponade
- Use interrupted or continuous locking sutures distal to proximal
- Usually 2-3cm long
- Mediolateral: begins midline of fourchette, extends 60 degrees right or left of the midline
- Lateral: begins 1-2cm lateral to midline, angled toward the right or left ischial tuberosity
- Aim to ultimately yield an incision 45 degrees off midline
Mediolateral episiotomy repair
- Anchor stitch 1cm beyond apex of wound
- Direct a running, locked, continuous suture to close vaginal epithelium, incorporating the rectovaginal fascia.
- Reapproximate the hymenal ring, first distally then with a suture proximal to the hymen – do not lock this suture, tie it off
- Use a single, continuous, non-locking suture to close the deeper layer of perineal tissue. This may not be required with small episiotomies.
- Identify the ends of the muscles of the perineal body.
- Reapproximate the ends of the transverse perineal muscles using 1 or 2 simple interrupted stitches.
- Reapproximate the ends of the bulbocavernosus muscle using a simple interrupted stitch (the crown stitch), often retracted posteriorly and superiorly.
- Using either a running subcuticular suture starting at the posterior apex or a mattress suture, reapproximate the skin.