THE MANAGEMENT OF THE MANAGEMENT OF

OBSTETRIC ANAL OBSTETRIC ANAL

SPHINCTER INJURYSPHINCTER INJURY

(EVIDENCE BASED)(EVIDENCE BASED)

Dr. Ashraf Fouda

Ob./Gyn. ConsultantOb./Gyn. Consultant

Damietta General HospitalDamietta General Hospital

Sources of Guidelines The Cochrane Library.

Medline and PubMed .

UpToDate ® August 2006 .August 2006 .

RCOGRCOG March 2007, THE MANAGEMENT OF THIRD-

AND FOURTH-DEGREE PERINEAL TEARS .

RCOGRCOG June 2004 , METHODS AND MATERIALS

USED IN PERINEAL REPAIR .

American Family Physician October

2003 .

Muscles of perineal body

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

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.

Applied anatomy

Obstetric anal sphincter injury

includes both

third- and fourth-degree

perineal tears.

IntroductionIntroduction

The overall risk of

obstetric anal sphincter injury is

1% of all vaginal

deliveries.

This condition may also present in This condition may also present in

women without obvious anal sphincter women without obvious anal sphincter

tears during labour and delivery tears during labour and delivery

(occult injury).(occult injury).

IntroductionIntroduction

Importance Anal incontinence is defined as any

involuntary loss of faeces, flatus or urge

incontinence that is adversely affecting

a woman’s quality of life.

Up to 40%Up to 40% of women with third or fourth of women with third or fourth

degree perineal tears during childbirth degree perineal tears during childbirth

suffer from anal incontinence. suffer from anal incontinence.

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.

Classification and terminology of perineal tears

THIRD DEGREE THIRD DEGREE PERINEAL TEARPERINEAL TEAR

FOURTH-DEGREE FOURTH-DEGREE PERINEAL TEARPERINEAL TEAR

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

Risk factors for obstetric anal Risk factors for obstetric anal sphincter injurysphincter injury

When episiotomy is indicated, the

mediolateral technique is

recommended, with

careful attention to the angle

cut away from the midline.

Prediction and prevention of Prediction and prevention of obstetric anal sphincter injuryobstetric anal sphincter injury

Grade B

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.

Prediction and prevention of Prediction and prevention of obstetric anal sphincter injuryobstetric anal sphincter injury

Normal anal ultrasound

How can the identification of obstetric How can the identification of obstetric

anal sphincter injuries be improvedanal 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

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)

End-to-end (approximation)

methodOverlap technique

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.

Surgical techniquesSurgical techniques

(Grade A)

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

Surgical techniquesSurgical techniques

(Grade C)

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.

Choice of suture materials

(Grade A)

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.

Choice of suture materialsChoice of suture materials

(Grade A)

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.

Choice of suture materialsChoice of suture materials

(Grade C)

(Good practice point)

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)

SurgicalSurgical competence 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)

Postoperative managementPostoperative 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)

All women who have had obstetric anal sphincter repair should be :

Offered physiotherapy and pelvic-floor exercises for 6–12 weeks after repair.

Reviewed 6–12 weeks postpartum by a consultant obstetrician and gynaecologist.

Postoperative managementPostoperative management

(good practice point)

PrognosisPrognosis

Women should be advised that the

prognosis following EAS repair is good,

with 60–80% asymptomatic at

12 months.

Most women who remain symptomatic

describe incontinence of flatus or

faecal urgency.(Grade A)

Future deliveriesFuture 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)

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.

Future deliveriesFuture deliveries

(good practice point)

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.

Risk managementRisk management

Practice recommendationsPractice 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 .

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.

Practice recommendationsPractice 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 .

Practice recommendationsPractice recommendations

All women, especially those with

risk factors for injury, should be

surveyed for symptoms of

anal incontinence

at postpartum follow-up .

Practice Practice recommendationsrecommendations