Obstetric anal sphincter injuries: strategies for prevention, diagnosis, and management

4D transperineal ultrasound: feedback for good obstetric anal sphincter injuries reparation

BACKGROUND

Obstetric anal injury is the main risk factor for traumatic anal, faecal and flatus, incontinence in women in reproductive age. Its recognition and good reparation are crucial for long term outcomes.

CASE REPORT

We report a case of a nulliparous woman who reported a fourth-degree perineal tear after delivery. The obstetric anal sphincter injury was repaired and a four-dimensional transperineal ultrasound was performed after reparation and then one and three months after discharge. The woman did not experience any incontinence and no points of discontinuity were observed at tomographic ultrasound imaging reconstruction. In this case, 4D-TPUS was a tool in the obstetrician's hands to evaluate the surgical success of OASIS repair, which requires some expertise.

CONCLUSIONS

4D-TPUS ultrasound is useful and reliable during immediate puerperium and in the subsequent follow-up, giving positive feedback on the correct positioning of the stiches and on a good healing process. Further studies are needed to demonstrate this usefulness in the operators training and for improving their surgical skills.

Use of endoanal ultrasound in detecting obstetric anal sphincter injury immediately after birth

INTRODUCTION

Obstetric anal sphincter injury (OASI) complicates around 5% of deliveries in primiparas. The study objective was to assess the utility of three-dimensional endoanal ultrasonography (3D-EAUS) in the diagnosis of OASI.

MATERIAL AND METHODS

The present study was designed to mirror screening settings with an unselected cohort of nulliparous women. All enrolled patients underwent clinical examination of the perineum by the caregiver, and 3D-EAUS was conducted. Post-processing of ultrasonography volume data was performed by an experienced colorectal surgeon who was blinded to all other data. The sensitivity, specificity, negative predictive value, and positive predictive value of 3D-EAUS in the diagnosis of OASI was evaluated. The trial is registered at ISCRTN: 18006769.

RESULTS

A total of 680 scans were performed, of which 18.5% were judged as "non-assessable", resulting in 554 assessable recordings. Sphincter defects were observed in 12.8% of all assessable recordings on 3D-EAUS (n = 71). With clinical examination set as the reference standard, ultrasound sensitivity in the diagnosis of OASI was 30.4%, whereas its specificity was 87.9%. The negative predictive value was 96.7% and the positive predictive value was only 9.9%. Comments were left on 175 examinations, of which 74% referred to the management of the examination.

CONCLUSIONS

Using 3D-EAUS in a maternity ward is demanding because staff generally have little experience in endoanal ultrasound, which contributes to difficulties in obtaining good image quality. When 3D-EAUS is performed to mirror screening settings, it adds no convincing diagnostic power to clinical examination in the diagnosis of OASI.