The Management of Third- and Fourth-Degree Perineal Tears

Question 1

Which suture materials should be used to accomplish repair of obstetric anal sphincter injuries?

Answer 1

3-0 polyglactin: anorectal mucosa ( less irritation and discomfort than polydioxanone (PDS)

• EAS, IAS muscle: monofilament as 3-0 PDS or modern braided as 2-0 polyglactin equivalent outcomes.
• burying of surgical knots beneath superficial perineal muscles is recommended to minimise risk of knot and suture migration to skin.

Question 2

General principles

Answer 2

• appropriately trained clinician or by a trainee under supervision.
• in operating theatre, under regional or general anaesthesia, with good lighting and with appropriate instruments.
• If excessive bleeding, vaginal pack inserted and take to theatre ASAP
• In delivery room may be in certain circumstances after discussion with senior obstetrician.
• Figure of eight sutures should be avoided haemostatic
  tissue ischaemia.
• rectal examination after to ensure that sutures not
  through anorectal mucosa. If identified, removed.

Question 3

Which techniques should be used to accomplish the repair of the anorectal mucosa?

Answer 3

• either continuous or interrupted technique.

Question 4

Which techniques should be used to accomplish the repair of the internal anal sphincter?

Answer 4

• torn IAS can be identified, it is advisable to repair this separately
• interrupted or mattress sutures without any attempt to overlap IAS.

Question 5

Which techniques should be used to repair the external anal sphincter?

Answer 5

• full thickness EAS tear, either overlapping or end-to-end (approximation) method: equivalent outcomes.
• partial thickness (all 3a and some 3b) tears, end-to-end technique.

Question 6

How can the identification of obstetric anal sphincter injuries be improved?

Answer 6

All having vaginal delivery

• examined systematically,
• including digital rectal examination,
• to assess the severity of damage, particularly prior to suturing.

Question 7

Can obstetric anal sphincter injury be predicted?

Answer 7

• however risk factors not allow accurate prediction of OASIS.

Question 8

Can obstetric anal sphincter injury be prevented?

Answer 8

• evidence for protective effect of episiotomy is
  conflicting.
• Mediolateral episiotomy in instrumental deliveries.
• Where episiotomy indicated, mediolateral, angle 60 degrees away from midline (perineum distended)
• Perineal protection at crowning can be protective.
• Warm compression in second stage reduces risk OASIS.

Question 9

How should obstetric anal sphincter injury be classified?

Answer 9

• any doubt about degree of third-degree tear, advisable to classify it to higher degree rather than lower degree.

Question 10

Who should repair obstetric anal sphincter injury?

Answer 10

• performed by appropriately trained practitioners.

- Formal training in anal sphincter repair techniques an essential component of obstetric training.

Question 11

How should women with obstetric anal sphincter injury be managed postoperatively?

Answer 11

• broad-spectrum antibiotics to reduce risk of postoperative infections and wound dehiscence.
• postoperative laxatives to reduce risk of wound dehiscence.
• Bulking agents not be given routinely with laxatives.
• Local protocols (antibiotics, laxatives, examination
  and follow-up) post repair.
• physiotherapy post-repair, could be beneficial.
• post-repair review at convenient time (usually 6–12 wks postpartum). by clinicians with special interest OASIS.
• experiencing incontinence or pain at follow-up, referral to specialist gynaecologist or colorectal surgeon.

Question 12

What is the prognosis following surgical repair?

Answer 12

• 60–80% of women are asymptomatic 12 months following delivery and EAS repair.

Question 13

What advice should women be given following an obstetric anal sphincter injury concerning future
pregnancies and mode of delivery?

Answer 13

• counselled about mode of delivery and clearly documented in notes.
• role of prophylactic episiotomy in subsequent pregnancies is not known and therefore performed if clinically indicated.
• symptomatic or abnormal endoanal ultrasonography and/or manometry should be counselled regarding option of elective caesarean birth.

Question 14

What processes and policies should be in place for women who have sustained obstetric OASIS?

Answer 14

• Units should have clear protocol for the management of OASIS.
• Documentation of anatomical structures involved, method of repair and the suture materials
• woman fully informed: nature of tear and offer of follow-up should be made, all supported by relevant written information.