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| 번호 | 제목 | 등록일 | 조회수 |
|---|---|---|---|
| 36 | Anal Sphincter Injury After Vaginal Delivery in Primiparous Females [2001년 9월 DCR] | 2011-11-17 | 3281 |
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Carlos Belmonte-Montes, M.D., Gonzalo Hagerman, M.D.,Paul Alan Vega-Yepez, M.D
From the Colorectal Clinic, Hospital Central Militar, Mexico Cily, Mexico
PURPOSE: The purpose of this study was to determine the incidence of anal sphincter injury and fecal incontinence after vaginal delivery.
METHODS: This was a prospective, descriptive, observational study conducted over a threeyear
period in healthy primiparous females with previously intact anal sphincter and normal continence and without history of anorectal surgery. All patients completed a continence questionnaire and underwent endoanal ultrasound four to six weeks before and six weeks after delivery. RESULTS: Ninety-eight primiparous females had either instrumental (vacuum or forceps) vaginal delivery (n = 23) or noninstrumental vaginal delivery (n = 75). Twenty patients, 11 (48 percent) after instrumental delivery and 9 (12 percent) after noninstrumental vaginal delivery, had clinical sphincter tears that required primary repair. Twenty-eight patients (29 percent), 19 with previously repaired sphincter injury, had ultrasonographic defects that involved the external sphincter (n = 19) or both the internal and external sphincter (n = 9). Twenty-one patients (75 percent) with ultrasonographic sphincter defects had either major (n = 5) or minor (n = 16) fecal incontinence. CONCLUSION: Anal sphincter injuries, many of them undiagnosed at the time of delivery, are common in primiparous females after vaginal delivery, especially if vacuum or forceps are used. These injuries cause fecal incontinence in a significant proportion of the patients. Patients undergoing vaginal delivery should be aware of the risks of anal sphincter injury.
Fecal incontinence is a common medical problem that is personally and socially incapacitating. It is
well known that fecal incontinence is more frequent in females than in males, and the reason for this difference is considered to be childbirth. Because the stigma of this condition is considerable, many patients hide their symptoms, and therefore, the true incidence of fecal incontinence remains unknown. Clinical trials have been undertaken to determine the cause of anal sphincter damage and symptoms of
fecal incontinence after vaginal delivery. Anal sphincter lesions occur more often during the first delivery, whereas pudendal neuropathy seems to be related to consecutive deliveries. Obstetric tears of the sphincter complex are often repaired at the time of delivery. However, recent studies have reported that many of these patients have a suboptimal outcome and complain of various degrees of anal incontinence. Repeated injuries of the anal sphincter occur with successive deliveries, which confuses analysis in populations of mixed parity. Therefore, we studied prospectively a group of healthy females delivering their first babies, in whom labor was managed according to a standardized, established protocol. The aim of the present study was to determine the incidence of anal sphincter injury and fecal incontinence after vaginal delivery in primiparous patients in Mexico. DISCUSSION
This prospective study, conducted exclusively in primiparous females, confirms previous observations
that anal sphincter injury is common after first vaginal delivery and that many of these sphincter injuries result in persistent fecal incontinence despite primary repair performed at the time of lesion formation. Thirteen percent of our patients had occult sphincter defects (ultrasound-detected sphincter defects in patients without clinically detected sphincter injuries at the time of delivery). This is lower than the incidence of occult sphincter defects reported by Sultan et al., who reported these defects in approximately one third of females having their first vaginal delivery. Although the incidence of occult sphincter defects in our patients may seem low, the combined incidence of clinically diagnosed and occult sphincter defects is not significantly different from the 20 percent incidence of ultrasound sphincter defects reported by ZetterstrOm et al. and is higher than the 14 percent reported by Varma et al.
We also found that a small group of patients without clinically diagnosed sphincter injury developed
fecal incontinence after vaginal delivery. All of these patients had newly diagnosed sphincter defects on the postpartum endoanal ultrasound. In our study, the incidence of clinical sphincter injuries diagnosed at the time of delivery (obstetric
third-degree tear) was higher than reported previously. The reason for this difference is unclear, but it may be attributed to several interrelated factors, such as the high proportion of IDs, the use of a midline episiotomy, and the focus of our study on primiparous patients. Sultan et al. described a strong association between the use of forceps and anal sphincter defects. In our study, more than half of the sphincter injuries diagnosed at the time of delivery could be attributed to IDs. Other studies that reported lower incidences of sphincter injuries included both primiparous and multiparous females, who have a lower risk of third-degree tears than primiparous patients. Midline or lateral episiotomies are usually performed to prevent uncontrolled pel-ineal lacerations at the time of vaginal deliveries, but other authors have claimed that episiotomy may contribute to anal sphincter injury. The preferential involvement of the EAS in the injuries identified by endoanal ultrasound suggests that an episiotomy may have a causative rote in obstetric injuries. However, our study was not designed to address this question. Twenty-eight percent of our patients had lesions detected with anal endosonography. Fifteen of them
had sphincter lesions diagnosed at the time of delivery. These results confirm previous observations by Sultan et al. Like other authors, we did not find isolated lesions of the IAS, as opposed to a report by Sultan et
al, but there was a similar result when Iesions in both sphincters were compared. In another study of patients with clinically detected lesions at the time of delivery, Sultan et al. reported that 85 percent of patients with a third-degree tear had a sphincter defect (1 that affected the IAS alone, 5 that affected the EAS, and 23 that affecte.d both anal sphincter muscles), and 47 percent suffered defecatory symptoms. Thirty-three percent of control patients were found to have sphincter defects (14 IAS alone, 5 EAS alone, and 10 both), and defecatory symptoms were noted in 13 percent of patients. Sultan et al. found that in females who experienced a third-degree tear, the sphincter defect was usually located along the full length of the sphincter. In the control group, the defect usually involved only a part of the sphincter length. We believe that our lesion pattern of the sphincter mechanism associated with incontinence could be t-elated to the use of medial episiotomy. Recent studies demonstrated that variables measured routinely on delivery are not a useful predictor
of anal sphincter injuries, except for forceps delivery, which was highly significant. Of the 23 patients who had ID in the present study (17 with the use of forceps and 6 with the use of vacuum delivery), 12 suffered third-degree tears (7 with forceps and 5 with vacuum delivery); 13 patients with forceps delivery had a lesion detected by anal endosonography, as did 3 with vacuum delivery. Varma et al, in a prospective study, found that routinely measured delivery variables are not useful predictors of latent sphincter injury, except for forceps delivery, which was found to be highly significant in predicting the presence of a sphincter injury. Johanson et al, in a randomized study of 600 females, also found a significantly higher incidence of maternal injuries after forceps delivery than with vacuum delivery. In another prospective study, Abramowitz et al. concluded that the use of forceps or vacuum greatly increases the risk for sphincter disruption and that EAS injury is more frequent than IAS injury. Their results are similar to those obtained in the present study. We excluded a considerable number of patients because they did not return for postpartum assessment.
Absence of symptomatologT could be assumed in patients who did not return for postpartum followup. However, another possible reason is that most of our patients were military personnel who frequently change residences and who were not necessarily asymptomatic. Another possible explanation is that undergoing an anorectal evaluation is uncomfortable and unpleasant for patients with minor symptoms. We believe that the patients who did not return for postparmm assessment were either asymptomatic, had moved, or had minor symptoms. In the study reported by Sultan and colleagues, none of the patients with disturbance of bowel function had spontaneously reported their symptoms or sought medical attention. Underreporting of such symptoms and the failure to seek medical attention are well known occurrences. We do not have data related to patients with a possible lesion of the sphincter detected, only on a
ctinical basis at the six-week postpartum assessment before ultrasonographic evaluation. However, we know that in patients who had a combined sphincter lesion, clinical evaluation strongly suggested a possible lesion. The use of ultrasonography is always considered far more objective and reliable than clinical evaluation.
We believe that patients with vaginal delivery who have risk factors should be followed up with ultrasonography. |
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