Third and Fourth Degree Tears: Management of CPG

• Definitions

• Risk factors

• Repair technique

• Post operative/postnatal management

• Subsequent management

• Planning the next birth

• Consumer information

1. Introduction/background

2. Definitions

• Second degree tear: involves the perineal muscles only1
  

• Obstetric anal sphincter injury: applies to both third- and fourth-degree tears1
  

• Third degree tear: injury to the perineum involving partial or complete disruption of the anal sphincter complex (external [EAS] and internal [IAS])
  

• Fourth degree tear: involves anal sphincter and rectal mucosa.1
  
  

3. Responsibility

• Clinicians: midwifery and medical staff caring for women in maternity services, in particular during labour and following birth
• Physiotherapists
• Dieticians
• CNC Urogynaecology
• Perineal Clinic Team: Experts in urogynaecology, colorectal, dietician, midwifery / continence nursing, physiotherapy and sexual counselling. The Perineal Clinic offers a multidisciplinary, best practice approach to the management and follow-up of anal sphincter injury with the aim to prevent/minimise long term complications.

4. Risk factors

• nulliparity
• asian or indian sub-continent ethnicity
• woman has Female Genital Mutilation (FGM)
• baby is large in relation to maternal size (> 4kg)
• previous history of perineal trauma requiring repair
• previous history of obstetric anal sphincter injury
• precipitate or faster than expected second stage
• instrumental birth
• active second stage longer than 1 hour
• inappropriate maternal position (e.g. lithotomy position)
• midline episiotomy or an inadequately angled mediolateral episiotomy which functions like a mid-line.

5. Guideline statements

5.1 Prediction and prevention

• Clinicians are required to complete and document a risk assessment for all women in labour.
• Clinicians must be aware of the risk factors for obstetric anal sphincter injury, but also recognise that known risk factors do not readily allow prediction/prevention of such an injury.1
  

• Where episiotomy is indicated, the mediolateral technique is recommended, with careful attention to the angle cut away from the midline.1
  
  

5.2 Classification

5.3 Recognition/identification

• All women should be examined to assess degree of perineal/vaginal/rectal injury after vaginal birth as follows:

5.4 Repair technique for third/fourth degree tears

• Extensive tears and all third and fourth degree tears should be repaired under general or regional analgesia (optimally in the operating theatre).1 Muscle relaxation is required to retrieve and overlap the retracted ends of the muscle without tension.
  
  

• Unless repaired under general anaesthesia, a midwife should remain with the woman during the repair to provide emotional support.2
  
  

• A consultant/senior level trainee experienced in third/fourth degree tear repair should be present.1 Repair should not be attempted by JMS without appropriate supervision.2
  
  

• A single dose of a broad spectrum prophylactic antibiotic should be administered at the time of repair.

• A repeat examination should be performed in theatre to adequately grade the tear.

• A torn anal epithelium is repaired using interrupted 2-0 Vicryl (polyglactin) sutures with the knots tied in the anal lumen.

• Torn ends of the external anal sphincter should be fully mobilized and repaired using an overlap technique. If the sphincter is only partially torn (<50%) then repair using an end-to-end technique with interrupted mattress sutures is acceptable. 2-0 PDSII (Polydioxanone) is the preferred suture material. Avoid using ‘figure-of-eight’ sutures unless for haemostasis, as end-to-end technique may be more vulnerable to ischaemia due to retraction of apposed sphincter muscles.1
  
  

• The internal anal sphincter should be identified and if torn, should be repaired separately with interrupted 2-0 PDSII (Polydioxanone) sutures using end-to-end or overlap technique.

• If the rectal mucosa is disrupted then this should be repaired using 2-0 Vicryl (polyglactin) sutures for interrupted sutures, or 2-0 PDSII (Polydioxanone) if submucosal continuous sutures are used.

• The perineal muscles and subcutaneous tissue should be repaired with 2-0 Vicryl (polyglactin). The perineal muscles must be reconstructed with care in order to provide support to the sphincter repair. A short, deficient perineum will increase the risk of further damage in a subsequent vaginal birth. Ensure that the knots are completely buried to avoid suture migration.2
  
  

• The perineal skin is approximated with a subcuticular or interrupted polyglactin suture.

• Perform a rectal examination at the end to ensure the repair is intact.

5.5 Post operative/postnatal management

• fully informed about the nature of her injury and benefits to her of follow-up
• provided with written consumer information
• seen by a physiotherapist to recommend an individualised program for commencing a pelvic floor muscle rehabilitation program as soon as comfortable, usually at about 3 days post birth/delivery
• seen by a dietician and commenced on a low residue diet for approximately 7 days. The purpose of this is to have a delayed, then soft and easy to pass stool.
• referred to CNC Urogynaecology to ensure follow up in the Women's Perineal Clinic 3 months post birth/delivery.

• Ice therapy, to decrease swelling for the first 48-72 hours. Apply an ice pack in a sanitary pad to the perineum for 20 minutes every 3-4 hours.
• Adequate analgesia such as non-steroidal anti-inflammatory analgesia, plus oral paracetamol. Avoid codeine containing analgesics as they may cause constipation.
• Avoid rectal analgesia.
• Laxatives or stool softeners (e.g. lactulose +/- fybogel) are advisable for about 7-10 days to avoid constipation and reduce the incidence of wound dehiscence.
• Adequate fluid intake (1.5-2L per day) especially if taking lactulose.

5.6 Subsequent management

• Commence pelvic floor muscle exercise regime in approximately 4-6 weeks. This will ensure the ability to recruit pelvic floor muscles for long term pelvic floor rehabilitation.

• At 12 weeks all women should be assessed with regard to sphincter integrity by endoanal ultrasound (Perineal Clinic – Wednesday Urogynaecology). Digital examination has only a 43% sensitivity rate for the identification of external anal sphincter defects compared with ultrasound. Some women may need ongoing treatment.

• All women should be reviewed as follows:

5.7 Planning the next birth

• All women who sustained an obstetric anal sphincter injury in a previous pregnancy should be counselled at the booking visit regarding the mode of birth and this should be clearly documented in the notes.
• All women who sustained a third/fourth degree tear in a previous pregnancy:

6. Appendices

7. Consumer information

8. Reference documents