Association and Outcome of the Primary Repair of Obstetric Perineal Injuries

Introduction Anal Sphincter injury (Third and forth degree tears) at vaginal delivery is the most common cause of feacal incontinence in otherwise healthy women. Obstetric injures complicate 0.5 -15% of vaginal deliveries. However, prevention of injury would obviate the need for surgical repair and associated short term morbidty. Patients and obstetrician have the universal desire to limit the incidence of injuries. It is however an unfortunate paradox that most of the risk factors for anal sphincter injures (primiparity, instrumental deliveries birth weight 7.4 kg) are components of normal labour and delivery process. The Majority of the women with these risk factors deliver vagnially, and sustain injuries. Several studies have identified a number of obstetric risk factors associate with sphincter injury. These include, nulliparty, large birth weight more than 4000 gms, forceps delivery, ventous delivery, epidural, induction of labour, delay in second stage of labour and persistent occipito posterior position of the fetus. Episiotomy appeared to be protective against sphincter injury, but evidences indicates that this may not be so. Recognized obstetric anal sphincter injuries (OASIS) occur in 0.4 – 19% of vaginal delivery in centers practicing mediolateral and midline episiotomies respectively. Previously there was confusion in classification of anal sphincter injuries. After having an audit on concept of classification, now a new classification was suggested, and this has now been accepted by the RCOG and the international consultation on incontinences (Table 1) OASIS therefore represent third and fourth degree tear.


Introduction
Anal Sphincter injury (Third and forth degree tears) at vaginal delivery is the most common cause of feacal incontinence in otherwise healthy women.Obstetric injures complicate 0.5 -15% of vaginal deliveries. 1 However, prevention of injury would obviate the need for surgical repair and associated short term morbidty. 2atients and obstetrician have the universal desire to limit the incidence of injuries.It is however an unfortunate paradox that most of the risk factors for anal sphincter injures (primiparity, instrumental deliveries birth weight 7.4 kg) are components of normal labour and delivery process. 3he Majority of the women with these risk factors deliver vagnially, and sustain injuries.
Several studies have identified a number of obstetric risk factors associate with sphincter injury.These include, nulliparty, large birth weight more than 4000 gms, forceps delivery, ventous delivery, epidural, induction of labour, delay in second stage of labour and persistent occipito posterior position of the fetus.Episiotomy appeared to be protective against sphincter injury, but evidences indicates that this may not be so. 4ecognized obstetric anal sphincter injuries (OASIS) occur in 0.4 -19% of vaginal delivery in centers practicing mediolateral and midline episiotomies respectively. 1,5reviously there was confusion in classification of anal sphincter injuries.After having an audit on concept of classification, now a new classification was suggested, 6 and this has now been accepted by the RCOG 7 and the international consultation on incontinences (Table 1) OASIS therefore represent third and fourth degree tear.

Methods
Cross Sectional study was carried out at women and children hospital of district Dera Ismail Khan, from 1 st July 2005 -31 December 2006.Midline episiotomy is not practiced in this institution and over all 3 rd degree pernical tear is proximally 2%.
Patients with sphincter injuries delivered outside the institution were also included in the study patients with injury but repaired outside the institute were not included.
Tears were repaired with vicry No. 1 by end to end approximation technique.Hospital stay was for 5 days and remained catheterized for 5 days.All women who have sustained recognized third degree tears, and repaired, return for follow up after 3 months of delivery.

No of Case % age
Third degree tear

Forth Degree Tear
Injury to perinem involving the anal sphincter & anal epithelium.
A total of 64 patients were found in 18 Month.Majority of the patients (59%) were having their first pregnancy.Among total patients, only 3 patients were having 4 degree tears, and all of them were referred from periphery and were delivered by midwife with history of injections and handling at home.In remaining 61 patients (95%) only 16 Patients (25%) were having mediolateral episiotomy.In hospital delivery 15 patients had instrumental deliver in which majority (85%) were having forceps delivery.Most of the babies were having forceps delivery.Most of the babies were having birth weight of 3.5 -4kg.In total 18 patients (28%) labour was induced with vaginal prostaglandin pessary.The patient with 4 th degree pernial tears were giving history of spontaneous onset of labour as they all were mishandled by local midwife.

Discussion
Our data confirmed that nulliparity, induction of labour, instrumental delivery (forceps, ventouse), birth weight > 4 Kg may be contributing factors for anal sphincter injuries.However the protective effect of episiotomy remains unclear.As the attitude of protecting perineal injury differs among obstetrician and midwife.On the other hand, protective interventions are either c/sections or routine episiotomy, but the protective effect of episiotomy is not clearly demonstrated in different studies.
Several authors have demonstrated a protective effect of medilateral epsiotomy 8,9 smaller angle of episiotomy likely?To lead to anal sphincer injury.It was unsurprising that majority of hospital deliveries sustaining tears veginal deliveries.It is a widely held belief that forceps, assisted delivery is more traumatic to the continence mechanism than vaccum extraction?
The range of birth weight was wide, and several women delivered macrocosmic babies.This emphasizes that fetal size has a subsidiary influence acting in combination with other intrapartum factors.The most devastating fact is that majority of sphincter injuries and those of 4 th degrees, they are delivered by untrained birth attendants either at home or some other place.These people use oxytocin injudiciously and most of then, even, cant perform episiotomies.Injudious use of exytocin and bad handling during labours lead to severe trauma and the another dark aspect of the fact is that, they are not referred in time for proper repair of the injury.Induction of Labour was also found having association with anal sphincter injury.As majority of the induced labour end up in instrumental deliveries, so it ma also be contributing factor in increasing the risk for erineal trauma.
It is definitely necessary to demonstrate that clinical examination at the time of delivery remains the cornerstone of diagnoses of anal sphincter damage.In each case, careful examination of perineum and vigina is mandatory along with rectal examination to exclude rectal or anal sphincter injury.
Visual inspection combined with palpation by performing a pill rolling motion between index finger in the rectum and the thumb over the anal sphincter, improves the detection rate of OASIS. 10 This can more be sphofisticated by supplementing endoanal ultrasound performed immediately postpartum, prior to suturing and then repeating several weeks later. 11This can help in detecting occult injuries because occult injuries also have risk of feacal incontinence after a subsequent viginal delivery.Feacal incontinence, fecal urgency, dysparenia and pernieal pain have been reported in 30-50% of women, who sustain such tears and symptoms may persist for several year after primary repair. 12aditionally, anal sphincter tears have been repaired at the time of injury by using the technique of end to end approximation of the torn anal sphincter.Recently a retrospective cohort study by sultanetall 13 suggested better outcomes using the overlap with end to end approximation found no signification difference in outcome 14 .

Conclusion
The most important aspect of the anal sphincter injury is prevention 15 .Thought most of the risks for injury are the components of birth process but skill and experience of the obstetricians while using instruments for delivery and mediolateral episiotomy can minimize the extent of injury.Not only 3 rd and 4 th degree tear, large number of occult injuries are missed at delivery.Therefore it is important that doctors and midwife must under go more focused intensive trainings to recognize these tears at delivery, along with this proper training in repair of sphincter injury is also mandatory.