Anal Sphincter Continence Following Secondary Repair of Third and Fourth Degree Perineal Tears – Comparison of Overlapping Versus End to End Anal Sphincter Repair.

Objective: To compare overlapping versus end-to-end repair techniques for secondary repair of 3rd and 4th degree perineal tears.
Design: Prospective randomized control trial.Setting: Combined Military Hospital Peshawar between Jan1999 to Sep 2003 & Military Hospital Rawalpindi between Oct 2003 to July 2008
Subjects: Women with an anal sphincter injury sustained during childbirth more than 6 weeks ago. Women were randomized into two groups –overlap repair and end to end repair. All repairs were performed in theatre under regional or general anaesthesia. Patients were followed up at 6 weeks for objective healing and 12 weeks with regard to restoration of continence and painful defecation. Patient satisfaction was also assessed using a scale of three.
Results: 34 eligible women were randomized. There was similar distribution of third and fourth degree tears in both groups. All repairs were performed by two senior consultants using standard technique. All patients had grade IV fecal incontinence  and it was restored to grade I in13(72%) versus 11(69%), and grade II 5(28%) versus 4(25%) in overlap and end to end anastomosis group respectively. There was no difference in success rate of both procedures (p=0.48). There were minimal short or long term complications in both groups.Patient satisfaction rates were equally high for both the procedures (p=0.74). All patients were very satisfied or satisfied in both groups
Results: A meticulously performed secondary repair can produce superior results with both techniques of secondary repair.
Key words: Anal incontinence, Obstetric anal sphincter repair, Secondary repair

Introduction

Anal incontinence has been termed as the “hidden problem1”, the unvoiced symptom2, as some women take it to be part of normal child bearing. It is called the secret disease of women –that complicates 0.6-20% of vaginal deliveries and results in considerable short and long term morbidity. Childbirth is responsible for eight time’s higher incidence of anal incontinence in women than in men. Occult to overt injuries to the anal sphincter can lead to immediate or delayed incontinence symptoms and the risk is increased by risk factors like primiparous status, macrosomic fetus prolonged 2nd stage, lithotomy position in labour, fundal pressure in labour, instrumental delivery and episiotomy3,4,5. Not all obstetric sphincter injuries are identified at the time of delivery6. Compression, stretching, tearing and local ischemia can cause pudendal neuropathy that may lead to fecal incontinence without demonstrable sphincter tear. The optimal technique for sphincter repair is controversial. End to end approximation is the most common technique, while few studies advocate overlapping technique. A systemic review shows that early primary overlap repair is associated with high success rate but data is scarce.

Most studies in the developed countries have been performed on primary repair or one recent study on delay by 8-12 hours. This study addresses secondary repair following at least 06 weeks after deliver. Four subjects in the study had repair done 10-15 years after deliver along with vaginal hysterectomy! There is a paucity of studies addressing this issue7,8.

Materials and Methods

The study was conducted over a period of 9 years and 8 months, initially in CMH Peshawar and last four and a half years in Military Hospital (MH) Rawalpindi. The aim of the study was to compare two repair techniques. All women reporting more than 6 weeks after delivery with 3^rd or 4^th degree tear were eligible for enrolment in the trial. Most women reported with traumatic vaginal delivery 6 weeks to 6 months ago. Two ladies came a long way for treatment of uterovaginal prolapse and were found to have sphincter tears 10-15 years old. They underwent vaginal hysterectomy along with sphincter repair. Both groups were matched with two each of such participants. Classification used was as recommended by Royal College of Obstetricians and Gynaecologists^9,10(RCOG) and International Consultation on Incontinence¹¹. Third degree tear was defined as partial or complete disruption of External anal sphincter (EAS) and Internal Anal sphincter (IAS).We did not specify sub classification of third degree tear in our study design but great majority were complete 3C. Fourth degree was defined as disruption of both EAS and IAS along with anal mucosa.All repairs were done when the old tear was free of any local infection and tissues were healthy. All patients received Lactulose syrup and Metronidazole 400mg three times a day five days before operation.

All were given liquid diet a day before surgery. Two consultants with more than 10 years experience in the procedure performed the operations. Hence there was no variation in the experience of participating consultant gynaecologists.Upon entry into the study all patients had grade 4 incontinence according to Park’s classification – Grade-1: no incontinence; Grade 2: incontinence to flatus; Grade3: incontinence to liquid faeces; Grade 4: incontinence to solid faeces. Complaints were scored positive if event occurred more than once per week. Though more sophisticated grading systems have now developed including Pescatori ¹² score that has been shown to be more reliable and sensitive for clinical correlation as it takes into account the number of episode of incontinence into account. In the 1^st four years of the study Park’s classification had been used so we had to continue with the same to keep the results comparable. In compliance with recommendations of RCOG^9,10 we used Vicryl 2/0 (polyglactin).

All repairs were performed under general or spinal anaesthesia in theatre with aseptic precautions. Patients with previous failed secondary  repair where overlapping was not deemed possible due to excessive scarring were excluded from the trial.For the overlap repair about 2cm of one end of sphincter was laid over the other in a double breasted jacket fashion¹³.

For end to end repair edges of sphincter were approximated with 3 or more interrupted sutures¹⁴. Internal sphincter could not be identified in these secondary repairs. Perineal muscles were sutured using interrupted sutures to make a muscular cylinder 2cm thick in both techniques. Finally vaginal mucosa was sutured using continuous non locking suture and perineal skin was closed   using interrupted sutures. Patients received 500mg IV Ampicillin along with 500mm Metronidazole. The antibiotics were continued IV for 24 hours followed by oral to complete 7 days of antibiotics. All patients were kept hospitalized for at least 48 hours after surgery. For the 1^st post operative day liquid diet was prescribed followed by Syrup Lactulose 10ml twice daily from 2^nd postoperative day. Subsequently normal diet was prescribed and laxatives continued for 2 more weeks. Patients were followed up at 6 weeks for evidence of objective healing by visual inspection of perineum and 12 weeks with assessment of incontinence using Park’s scoring, painful defecation and patient satisfaction.Statistical analyses: Comparison between the 2 groups was performed using Fisher’s exact test or chi-square test. P value of 0.05 was considered to be the limit of statistical significance.

Table I: Demographic and etiological factors