Lesiones del suelo pélvico tras parto vaginal con forceps evaluadas mediante ecografía 3/4d transperineal

Objetivos: Determinar una tasa precisa de avulsión del músculo elevador del ano (MEA) asociada al uso de fórceps, teniendo en cuenta las características de la instrumentación, evaluada por ecografía translabial tridimensional. Material y métodos: Se realiza un estudio observacional prospectivo en el periodo de tiempo comprendido entre septiembre 2016 y marzo 2017. Tras el parto, todas las primíparas con un parto vaginal eutócico o un parto instrumentado con fórceps fueron invitadas a participar en el estudio, reclutando a un total de 183 pacientes, de las cuales 176 completaron el estudio (89 en el grupo de ‘fórceps’ y 87 en el grupo de ‘eutócicos’ (96.2%). Se recogieron parámetros obstétricos generales, así como las características de instrumentación: altura de la presentación (‘medio’: III plano, ‘bajo’: IV plano de Hodge), posición (occipito-anterior, occipito-posterior, transversa), presencia de asinclitismo y si se realizó desarticulación y retirada de las ramas antes del nacimiento. Entre los 6 y 12 meses postparto se realizó una evaluación del músculo elevador del ano mediante ecografía transperineal 3-4 dimensiones (3-4D) que incluyó la captura de 6 volúmenes por paciente: 2 en reposo, 2 en Valsalva y 2 con contracción máxima. La avulsión del músculo elevador del ano se estableció utilizando el modo ‘Multiview’ (obtenido a partir del plano de mínimas dimensiones), en aquellos casos en los que se apreció discontinuidad entre las fibras del músculo puborrectal y la rama púbica inferior en los 3 cortes centrales. El microtrauma se definió como un aumento ≥ 20% en el área del hiato al Valsalva. Resultados: Se identificó una avulsión del músculo elevador del ano en 46 mujeres (26%), con 12 casos (13,8%) pertenecientes al grupo de pacientes ‘eutócicos’ y 34 (38,2%) al grupo de ‘fórceps’ (p = 0,005, OR cruda 4 (1,5-10,4) y multivariante del OR ajustada 5.46 (1.91- 15.61)). No se objetivó una diferencia significativa en la tasa de microtrauma entre grupos de estudio. Conclusiones: El uso del fórceps de forma estandarizada es un factor de riesgo para la avulsión del músculo elevador del ano

Influence of difficulty of instrumentation with vacuum on the rate of levator ani muscle avulsion identified by 3–4 d transperineal ultrasound

Objectives: Evaluation of the influence of difficulty of instrumentation with vacuum on the rate of levator ani muscle (LAM) avulsions. Materials and methods: Prospective observational study with 86 nulliparous women with at term gestation who required instrumentation with vacuum to complete fetal extraction. After every delivery, each explorer reported the number of vacuum tractions needed to complete fetal extraction, as well as the subjective complexity of the instrumentation. LAM avulsion rate was assessed by 3D–4D transperineal ultrasound evaluation 6 months after delivery. Results: Seventy nine cases were evaluated and classified as either “easy” delivery (below three vacuum tractions; n = 49) or “difficult” delivery (three or more vacuum tractions; n = 30). No differences in obstetric characteristics were observed between study groups, with the following exceptions: fetal head circumference (34.8 ± 2.7 versus 35.2 ± 1.1; p = .013) and fetal weight at birth (3260 ± 421 versus 3500 ± 421; p = .016). No statistically significant differences between study groups were observed in LAM avulsion rate (36.7 versus 30%) and levator hiatus area (cm2) at rest (18.44 ± 3.95 versus 17.75 ± 3.90). Conclusions: The number of vacuum tractions needed to complete fetal extraction is not associated to a higher LAM avulsion rate nor with differences in levator hiatus area

Can we predict levator ani muscle avulsion in instrumental deliveries through intrapartum transperineal ultrasound?

Introduction: To determine whether intrapartum translabial ultrasound (ITU) is useful for the prediction of levator ani muscle (LAM) avulsions in instrumental deliveries (vacuum and forceps). Materials and methods: Prospective, observational study, including (1/2016 − 5/2016) 77 nulliparous women, with singleton pregnancies of ≥37 weeks of gestation and with cephalic presentation, who required vacuum or forceps instrumentation to complete the delivery. The ITU parameters evaluated were Angle of Progression (AoP), Progression Distance (PD), Head Direction (HD), and Midline Angle (MLA), both at rest and with maternal push. Evaluation of LAM avulsion was performed at 6 months postpartum with 3–4D transperineal ultrasound. Complete avulsion was defined as an abnormal insertion of LAM in the lower pubic branch identified in all three central slices. Results: Data from 48 nulliparous women were finally included in the study (34 vacuum and 14 forceps). We observed no difference in obstetric parameters between the two study groups (group with avulsion of LAM −14 cases, 29.2% − and group without avulsion of LAM −34 cases, 70.8%). The “LAM avulsion group” had an AoP and a PD of 136.7 ± 22.4 and 43.5 ± 15.6, respectively, versus 141.6 ± 21.3 and 47.2 ± 16.8 recorded in the group without avulsion (NS), respectively. We obtained a ROC curve for AoP and PD with a push of 0.66 (95% CI, 0.28–1.00) and 0.57 (95% CI, 0.39–0.75), respectively. Conclusions: ITU is not a useful technique to predict the occurrence of LAM avulsion in instrumental deliveries with vacuum or forceps