Perineal and Anal Sphincter Trauma (eBook)

Foreword 5
Preface 6
Contents 7
Contributors 9
Anatomy of the Perineum and the Anal Sphincter 11
Diagnosis of Perineal Trauma 23
Repair of Episiotomy, First and Second Degree Tears 30
Third and Fourth Degree Tears 43
Prevention of Perineal Trauma 62
Postpartum Problems and the Role of a Perineal Clinic 75
Female Genital Mutilation 90
Pathophysiology of Anal Incontinence 99
Investigations of Anorectal Function 112
Imaging of the Anal Sphincter 133
Conservative Management of Anal Incontinence 143
Surgical Management of Anal Incontinence Part A. Secondary Anal Sphincter Repair 154
Surgical Management of Anal Incontinence Part B. Advanced Surgical Techniques 164
Rectovaginal Fistulas 176
Medicolegal Considerations: The British and U.S. Perspective 188
Index 198

5 Prevention of Perineal Trauma (p. 52-53)

Ranee Thakar and Erica Eason

Perineal trauma can be associated with considerable short- and long-term morbidity. Perineal laceration and episiotomy are painful, incur blood loss, and may become infected, fistulae occasionally follow. Long-term, other complications of obstetrical trauma to the pelvic floor may affect women’s lives even more than the immediately apparent laceration. Dyspareunia related to the tear and its repair may last for months or even years. Pelvic floor muscles and nerves may be stretched, torn or sheared from their attachments, as shown in magnetic resonance imaging studies, resulting in urine leakage, urgency or incontinence of faeces or flatus, or pelvic organ prolapse.

Apart from the physical and hormonal aspects of pregnancy, the specific effects of childbirth have not yet been clearly distinguished, although some light has been shed by prospective studies, especially by the Term Breech Trial, in which planned vaginal or caesarean birth was randomly assigned.

On the other hand, some symptoms present at 3 months postpartum (a time frequently chosen by researchers for postpartum assessment) may be caused in part by the very low oestrogen levels, which are due to breast feeding but resolve after weaning the infant. For instance, dyspareunia may be due to atrophic vaginitis, and urinary urgency to thinned uroepithelium of the urethra and bladder base. While a good deal of research into the sequelae of obstetric perineal trauma has focussed on urodynamics, pudendal nerve function, or imaging of the muscles of the pelvic floor and anal canal, one must keep in mind that these, and even observed anal sphincter lacerations, are proxy measures for the out- comes of importance to women: continence and comfort.

On a population health basis, preventing perineal trauma in even a modest proportion of childbearing women would benefit large numbers of women. It would also reduce both the cost of childbirth (with fewer sutures and less suturing time required) and the need of medical care for sequelae such as urinary and faecal incontinence.

5.1 Interventions to Prevent Obstetrical Perineal Trauma

The case for perineal trauma prevention during childbirth is compelling, and the low trauma rates achieved by some practitioners attest that there are effective ways to do so. In the past few decades, great strides have been made toward subjecting traditional care practices in care during pregnancy and childbirth to randomised controlled trial (RCT) and systematic review. Regrettably, these studies have had flaws assessing a limited range of perineal outcomes and following participants for a few months at best. Many aspects of pregnancy, labour and delivery care thought to affect perineal trauma have yet to be subjected to rigorous assessment. Birthing methods used by practitioners with low rates of perineal trauma need to be identified and evaluated. Therefore we will summarise the evidence for interventions potentially affecting the rate of perineal trauma, focusing primarily on the evidence from RCTs.

We first discuss interventions with evidence from RCTs, in the order in which a decision about whether an intervention might have to be made in the course of patient care. We then mention other interventions for which evidence is weaker or lacking, in like order.