THE MANAGEMENT OF OBSTETRIC ANAL SPHINCTER INJURY (EVIDENCE BASED)

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THE MANAGEMENT OF OBSTETRIC ANAL SPHINCTER
INJURY (EVIDENCE BASED)

• Dr. Ashraf Fouda
• Ob./Gyn. Consultant
• Damietta General Hospital

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Sources of Guidelines

• The Cochrane Library.
• Medline and PubMed .
• UpToDate August 2006 .
• RCOG March 2007, THE MANAGEMENT OF THIRD- AND
  FOURTH-DEGREE PERINEAL TEARS .
• RCOG June 2004 , METHODS AND MATERIALS USED IN
  PERINEAL REPAIR .
• American Family Physician October 2003 .

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Muscles of perineal body
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Applied anatomy

• The anal canal measures about 3.5 cm in length.
• The external anal sphincter (EAS) is striated
  muscle and is subdivided into subcutaneous,
  superficial and deep regions and is responsible
  for voluntary squeeze and reflex contraction
  pressure
• It is innervated by the pudendal nerve

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Applied anatomy

• The internal anal sphincter (IAS) is a thickened
  continuation of the circular smooth muscle of
  the bowel.
• It contributes about 70 of the resting pressure
  and is under autonomic control.

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Introduction

• Obstetric anal sphincter injury includes both
  third- and
  fourth-degree perineal tears.

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Introduction

• The overall risk of
  obstetric anal sphincter injury is
  1 of all vaginal deliveries.
• This condition may also present in women without
  obvious anal sphincter tears during labour and
  delivery (occult injury).

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Importance

• Anal incontinence is defined as any involuntary
  loss of faeces, flatus or urge incontinence that
  is adversely affecting a womans
  quality of life.
• Up to 40 of women with third or fourth degree
  perineal tears during childbirth suffer from anal
  incontinence.

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Classification and terminology of perineal tears

• by International Consultation on Incontinence and
  the RCOG.
• First degree Injury to perineal skin only.
• Second degree Injury to perineum involving
  perineal muscles but not involving the anal
  sphincter.
• Third degree Injury to perineum involving the
  anal sphincter complex (EAS and IAS)
• 3a Less than 50 of EAS thickness torn.
• 3b More than 50 of EAS thickness torn.
• 3c Both EAS and IAS torn.
• Fourth degree Injury to perineum involving the
  anal sphincter complex and anal epithelium.

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THIRD DEGREE PERINEAL TEAR
FOURTH-DEGREE PERINEAL TEAR
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Risk factors for obstetric anal sphincter injury

• Birth weight over 4 kg
• Persistent occipitoposterior position
• Nulliparity
• Induction of labour
• Epidural analgesia
• Second stage longer than 1 hour
• Shoulder dystocia
• Midline episiotomy
• Forceps delivery

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Prediction and prevention of obstetric anal
sphincter injury

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

Grade B
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Prediction and prevention of obstetric anal
sphincter injury

• With introduction of endoanal ultrasound,
  sonographic abnormalities of the anal sphincter
  anatomy has been identified in up to 36 of women
  after vaginal delivery, in prospective studies.
• A lower risk of third-degree tear is
  associated with a larger angle of episiotomy.

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

• All women having a vaginal delivery
  with evidence of genital tract trauma should be
  examined
  systematically to assess
  the severity of damage prior
  to suturing.

Grade B
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Surgical techniques

• For repair of the external anal sphincter, either
  an overlapping or end-to-end (approximation)
  method can be used, with
  equivalent outcome.
• Where the IAS can be identified, it is advisable
  to repair separately with interrupted sutures.
• Repair of third- and fourth-degree tears should
  be conducted in an operating theatre, under
  regional or general anaesthesia.

(Grade A)
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End-to-end (approximation) method
Overlap technique
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Surgical techniques

• A systematic review on the method of repair
  showed that
  no significant difference in
  
  perineal pain ,dyspareunia ,flatus incontinence
  and faecal incontinence quality of life between
  the two repair techniques at
  12 months
• But showed a significantly lower incidence in
  faecal urgency in the overlap group.

(Grade A)
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Surgical techniques

• Repair in an operating theatre will allow the
  repair to be performed under aseptic conditions
  with appropriate instruments, adequate light and
  an assistant.
• Regional or general anaesthesia will allow the
  anal sphincter to relax, which is essential to
  retrieve the retracted torn ends of the sphincter
  without any tension

(Grade C)
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Choice of suture materials

• The use of absorbable synthetic material
  polyglactin 910 (vicryl) when compared with
  catgut, is associated with less
• Perineal pain,
• Analgesic use,
• Dehiscence and
• Resuturing,
  but increased suture
  removal.

(Grade A)
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Choice of suture materials

• The use of a more rapidly absorbed form of
  polyglactin 910 (Vicryl) is associated with a
  significant reduction in pain and a reduction in
  suture removal when compared with standard
  absorbable synthetic material.
• In the light of current evidence,
  rapid-absorption polyglactin 910 (Vicryl)
  is the most appropriate suture material
  for perineal repair.

(Grade A)
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Choice of suture materials

• When repair of the IAS muscle is being performed,
  fine suture size such as 3-0 PDS and 2-0 Vicryl
  may cause less irritation and discomfort.
  
• Burying of surgical knots beneath the superficial
  perineal muscles is recommended to prevent knot
  migration to the skin.
  

(Grade C)
(Good practice point)
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Method of repair

• A loose, continuous non-locking suturing
  for
  (vaginal tissue, perineal muscle and skin)
  the use of a continuous subcuticular
  technique for perineal skin closure is associated
  with less short term pain than techniques
  employing interrupted sutures.

(Grade A)
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Surgical competence

• Obstetric anal sphincter repair
  should be performed by appropriately
  trained practitioners.
• Formal training in anal sphincter repair
  techniques, is recommended as an essential
  component of obstetric training.

(Good practice point)
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Postoperative management

• The use of broad-spectrum antibiotics is
  recommended to reduce the incidence of
  postoperative infections and wound dehiscence.
  
• The use of postoperative laxatives is
  recommended to reduce the incidence of
  postoperative wound dehiscence.

(good practice point)
(Grade C)
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Postoperative management

• All women who have had obstetric anal sphincter
  repair should be
• Offered physiotherapy and
  pelvic-floor exercises for 612 weeks
  after repair.
• Reviewed 612 weeks postpartum by a
  consultant obstetrician and gynaecologist.

(good practice point)
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Prognosis

• Women should be advised that the prognosis
  following EAS repair is good, with 6080
  asymptomatic at 12 months.
• Most women who remain symptomatic describe
  incontinence of flatus or faecal urgency.

(Grade A)
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Future deliveries

• All women with an obstetric anal sphincter injury
  in a previous pregnancy should be
• Counselled about the risk of developing anal
  incontinence or worsening symptoms with
  subsequent vaginal delivery.
• Advised that there is no evidence to
  support the role of prophylactic episiotomy
  in subsequent pregnancies.

(good practice point)
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Future deliveries

• All women with an obstetric anal sphincter injury
  in a previous pregnancy and who are symptomatic
  or have abnormal endoanal ultrasonography
  should have the option
  of elective caesarean birth.

(good practice point)
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Risk management

• There is a steady increase in litigation related
  to obstetric anal sphincter injury.
• Litigation is related to failure to identify the
  injury after delivery, leading to subsequent anal
  incontinence and rectovaginal fistulae.
• Poor technique, poor materials or poor healing
  may cause a repair to fail.

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Practice recommendations

• Avoiding obstetrical injury to the anal sphincter
  is the single biggest factor in preventing anal
  incontinence .
• Any form of instrumental delivery has been noted
  to increase the risk of obstetric anal sphincter
  injury and altered fecal continence , by between
  2-7 fold .

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Practice recommendations

• Routine episiotomy is not recommended.
• Episiotomy use should be restricted to situations
  where it directly facilitates an urgent delivery
  .
• A mediolateral incision, instead of a midline,
  should be considered for persons at high risk of
  obstetric anal sphincter injury ,with careful
  attention to the angle cut away from the midline.
  

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Practice recommendations

• The internal anal sphincter needs to be
  separately repaired, if torn .
• Women with injuries to the internal anal
  sphincter or rectal mucosa have a worse
  prognosis for future continence
  problems .

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Practice recommendations

• All women, especially those with risk factors for
  injury, should be surveyed for symptoms
  of anal incontinence at
  postpartum follow-up .

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Thank You