Seniority and Experience Matter!  Inform the Senior Obstetrician on call. 

• Repair should not be attempted by an inexperienced doctor.
• Any middle grade undertaking repair must have been suitably trained and signed off as competent. 
• 4^th degree and Buttonhole tears require consultant to be in attendance, even if trainee has been signed off for repairs of Obstetric Anal Sphincter Injuries (OASIs).
• Bleeding points should be identified and secured. Figure of eight sutures should be avoided as they can lead to tissue ischemia (Green top Guideline 2015). If there is excessive bleeding, a vaginal pack should be inserted, and the woman taken to theatre as soon as possible and Tranexamic Acid 1g IV (slow bolus) should be administered.
• If there is a delay taking the woman to theatre, then a Foleys catheter should be inserted.

Location. All repairs must be conducted in the operating theatre: good lighting, appropriate equipment and aseptic conditions

Equipment. Use the specially prepared Advanced Perineal Repair Pack

Assistant Ensure a scrubbed assistant and scrub nurse/midwife are present

Anaesthesia. All repairs must be performed under general or regional anaesthesia. This is a particularly important pre-requisite for an overlap repair as the inherent tone in the sphincter muscle can cause the torn muscle ends to retract within its’ sheath. Muscle relaxation is necessary to retrieve the ends and overlap without tension.

Evaluation. The full extent of the injury should be determined by a careful vaginal and rectal examination in lithotomy. Classifytear as above, if there is any doubt about the degree of the tear, it is advisable to classify to a higher degree rather than a lower degree.

Littlewoods’s forceps must not be used on any anal sphincter complex as it increases tissue trauma, bleeding and ischaemia (GTG 2015)

The torn anal epithelium must be repaired either with interrupted Vicryl/Polysorb 3-0 sutures with the knots preferably tied in the anal lumen or by a continuous submucosal stitch.

An internal anal sphincter tear must be must be identified and grasped with Allis  tissue forceps and repaired separately by end-to-end approximation  with interrupted 3-0 PDS sutures.

The torn ends of the external anal sphincter must be identified and grasped with Allis tissue forceps. The muscle is then mobilized to allow repair. Repair with 3.0 PDS

• Partial (All 3a tears and some 3b) tears should be repaired by ‘End-toEnd’ technique
• Complete EAS tears (3b) can be repaired by either ‘End-to-End’ technique or ‘Overlap’ technique

A buttonhole injury repair should be performed using the following steps:

• The torn anal epithelium must be repaired either with interrupted Vicryl/Polysorb 3-0 sutures or by a continuous submucosal stitch.
• Consideration should be given to a second layer defect closure, or interposition of fascial tissue using Vicryl/Polysorb 3-0
• Vaginal skin closed with interrupted or continuous Vicryl/Polysorb 2-0

A defunctioning stoma to support these repairs is very rarely needed in obstetric patients undergoing primary repair at time of delivery. 

Following repair of anal sphincter, repairing the perineal muscles to reconstruct the perineal body is very important. This provides support to the sphincter repair and pelvic floor, improving outcomes for patients. Remember that the anal sphincter would be more likely to be traumatised during a subsequent vaginal delivery in the  presence of a short deficient perineum.

It is recommended that surgical knots are buried beneath the superficial perineal muscles to minimise the risk of knot and suture migration to the skin.

A rectal examination should be performed after the repair to ensure that sutures have not been inadvertently inserted through the anorectal mucosa. If a suture is identified, it should be removed.

Immediate Aftercare

Urinary Catheter. Severe perineal discomfort particularly following instrumental delivery is a known cause of urinary retention and following regional anaesthesia, it can take up to 12 hours before bladder sensation returns. A Foley’s catheter should be left in for at least 24 hours. (See GGC Postnatal Bladder Care Guideline).

Antibiotic cover

See GGC Antibiotic prophylaxis protocol with dosage dependent on maternal weight.

The HEPMA OASI Care Bundle should be prescribed which includes analgesia and stool softeners. This includes Movicol 1 sachet TID PO for 14 days with reduction of dose in case of diarrhoea, Paracetamol 1g, QDS, regular prescription (reduce to 500mg if maternal weight <50kg) and Diclofenac 50mg TID, regular prescription. 

Consider modification of this HEPMA bundle in case of pre-existing patient risk factors. Consideration should be given to Sevredol for breakthrough pain in these women only when no relief is obtained with simple analgesics. Bulking agents should not be given routinely with laxatives. PR medication is not advised.

Patients are not expected to move their bowels in the hospital before discharge. 

Thromboprophylaxis assessment

As per GGC protocol.

Notes

As the consequences of anal sphincter disruption can result in litigation, careful and detailed documentation is essential. A diagram demonstrating the extent of the injury and technique of repair is useful to have and will serve to substantiate that a careful examination was performed.

Explanation

The woman should receive detailed information regarding the extent of  trauma / repair.

• She should be advised that if there are concerns about infection or poor bowel control, she should seek midwife or GP and that she may be referred to hospital where appropriate.
• She should also be made aware that physiotherapy following a sphincter injury is beneficial. All patients should be reviewed on the ward by physiotherapy team prior to discharge.
• Women should be advised that 60-80% of women are asymptomatic 12 months following delivery and sphincter repair.

All patients must receive an information leaflet (RCOG or GG&C)

Record

Careful documentation in Intrapartum Operative Proforma.

The details should be recorded in such a way to be retrievable for audit purposes and entered into Datix.

Follow-up

Appointment should be made for 3 months post-natal with either:

• Patient’s consultant (GRI & RAH deliveries)
• Perineal Clinic (QEUH deliveries). Please copy all discharge letters to Dr Guerrero at QEUH

Patients with ongoing problems following OASIS from other units can be seen at Perineal clinic (new Victoria ACH) following Consultant-Consultant referral to Urogynaecology Consultant  team

• Any woman with a history of a third/fourth degree tear should be reviewed by her consultant during the antenatal period.
• A recurrence risk of 5-7% should be quoted if having another vaginal delivery.
• Most women, following assessment and discussion with their consultant will be encouraged to have a normal delivery, if asymptomatic and there are no clinical concerns. However, there should be an individualised discussion with each woman.
• Women who are symptomatic or have abnormal endoanal ultrasound/manometry and those who have had a 4^th degree tear, should have a LUSCS discussed with them. Onwards referral to Perineal Clinic may be appropriate if further assessment is required.
• There is no evidence that prophylactic episiotomy prevents a recurrence of sphincter rupture and therefore an episiotomy should only be performed if clinically indicated.

Instruments

• Weislander’s Retractor
• Tooth forceps (fine and strong)
• Needle holder (small and large)
• Allis forceps (4)
• Artery forceps (6)
• McIndoe scissors
• Stitch cutting scissors
• Sims speculum
• Deep vaginal side wall retractors
• Sponge holding forceps (4)
• Tampon
• Large swabs
• Diathermy
  
  

Sutures

• Anal epithelium
  Ethicon Vicryl 3-0, 26mm round bodied needle W9120 

• Internal anal sphincter
  Ethicon PDS 3-0, 26mm round bodied needle W9124T 

• External anal sphincter 
  Ethicon PDS 3-0, 26mm round bodied needle W9124T 

• Perineal muscles
  Ethicon Vicryl rapide 2-0, 35mm tapercut needle W9124 

• Perineal skin 
  Ethicon Vicryl rapide 2-0, 35mm tapercut needle W9124
  (can be used for subcuticular or interrupted sutures)