| Abstrakt: |
Obstetric anal sphincter injury (OASI) is the most common cause of anal incontinence and ano-rectal symptoms in women1 . Reported rates of anal incontinence following primary repair of OASI range between 15-61%, with a mean of 39%2, 3 . Other possible complications of OASI include perineal pain, dyspareunia, and less commonly, abscess formation, wound breakdown, and rectovaginal fistulae. Symptom onset may occur immediately, several years postpartum, or only late in life when aging of tissues adds to the delivery insult. Having sustained an OASI may impact significantly on women's physical and emotional health. Missed OASI, inadequate repair or lack of follow up are potential sources of litigation4 . The reported incidence of OASI may be as high as 4-6.6%4 , averaging 2.9% in the UK3 . The incidence is higher in primiparae (6.1%) than in multiparae (1.7%) 3 . Recent years are seeing an increased awareness and structured training programs, which appear to have resulted in an increase in the detection rate of OASI3 . The following risk factors have been identified with varying risk rates reported3 : Asian ethnicity (OR 2.27, 95% CI 2.14-2.41), nulliparity (relative risk [RR] 6.97, 95% CI 5.40-8.99), birth weight greater than 4 kg (OR 2.27, 95% CI 2.18-2.36), shoulder dystocia (OR 1.90, 95% CI 1.72-2.08), occipito-posterior position (RR 2.44, 95% CI 2.07-2.89), prolonged second stage of labor (up to RR 2.02, 95% CI 1.62-2.51 after four hours duration). Instrumental deliveries and episiotomy use have been extensively studied resulting in the following evidence: Vacuum delivery without episiotomy (OR 1.89, 95% CI 1.74-2.05); vacuum delivery with episiotomy is protective (OR 0.57, 95% CI 0.51-0.63); forceps delivery without episiotomy carries the highest potential risk (OR 6.53, 95% CI 5.57-7.64); and forceps delivery with episiotomy (OR 1.34, 95% CI 1.21-1.49). Other potential risk factors have been suggested with varying evidence such as advanced maternal age at first birth, Asian race, a vaginal birth after cesarean, and type of obstetrical care provider4 . Possible protective factors include obesity, perineal massage (RR 0.91, 95% CI 0.86-0.96)5 , perineal protection at crowning3 , warm compression during the second stage of labor (RR 0.48, 95% CI 0.28-0.84)3 , mediolateral episiotomy in instrumental deliveries6 , a wide angle of the mediolateral episiotomy (at least 60 degrees away from the midline when the perineum is distended) 7 , and pre-labor cesarean section4 . However, clinicians and patients alike should be aware that risk factors do not allow the accurate prediction of OASI3 . OASI is usually diagnosed in the immediate postpartum period. The classification is based on the extent of lacerations to the external and internal anal sphincter (EAS and IAS, respectively) and epithelium as devised by Sultan 2,3,8 (Figure 1) and adopted by the World Health Organization (WHO). The degree of damage impacts on the development of symptoms, with 3C and 4th degree tears carrying a graver prognosis than 3A and 3B tears9 . It is not unusual for a tear to be missed in the labor ward: the reported rates of missed OASI range from 26-87%10 . Since all women having a vaginal delivery are at risk of sustaining OASI, they should be examined systematically, including a digital rectal examination, to assess the severity of damage, prior to suturing3 . [ABSTRACT FROM AUTHOR] |
Plný text