Ultrasound evaluation of uterine scar thickness after open fetal surgery for myelomeningocele.

PURPOSE: This study aimed to analyse the evolution of uterine scar thickness after open fetal surgery for myelomeningocele (MMC) by ultrasonography, and to establish a cut-off point for uterine scar thickness associated with high-risk of uterine rupture. METHODS: A prospective longitudinal study was conducted with 77 pregnant women who underwent open fetal surgery for MMC between 24 and 27 weeks of gestation. After fetal surgery, ultrasound follow-up was performed once a week, and the scar on the uterine wall was evaluated and its thickness was measured by transabdominal ultrasound. At least five measurements of the uterine scar thickness were performed during pregnancy. A receiver operating characteristics (ROC) curve was constructed to obtain a cut-off point for the thickness of the scar capable of detecting the absence of thinning. Kaplan-Meier curves were constructed to evaluate the probability of thinning during pregnancy follow-up. RESULTS: The mean ± standard deviation of maternal age (years), gestational age at surgery (weeks), gestational age at delivery (weeks), and birth weight (g) were 30.6 ± 4.5, 26.1 ± 0.8, 34.3 ± 1.2 and 2287.4 ± 334.4, respectively. Thinning was observed in 23 patients (29.9%). Pregnant women with no thinning had an average of 17.1 ± 5.2 min longer surgery time than pregnant women with thinning. A decrease of 1.0 mm in the thickness of the uterine scar was associated with an increased likelihood of thinning by 1.81-fold (95% confidence interval [CI]: 1.32-2.47; p < 0.001). The area below the ROC curve was 0.899 (95% CI: 0.806-0.954; p < 0.001), and the cut-off point was ≤ 3.0 mm, which simultaneously presented greater sensitivity and specificity. After 63 days of surgery, the probability of uterine scarring was 50% (95% CI: 58-69). CONCLUSION: A cut-off point of ≤ 3.0 mm in the thickness of the uterine scar after open fetal surgery for MMC may be used during ultrasonography monitoring for decision-making regarding the risk of uterine rupture and indication of caesarean section.

Assessment of lower limb trophism in fetuses with open spina bifida using fractional thigh volume of three-dimensional ultrasound.

OBJECTIVE: To assess the trophism of the lower limbs of fetuses with open spina bifida using fractional thigh volume (TVOL) of three-dimensional (3D) ultrasound. METHODS: A prospective cross-sectional study was carried out with normal fetuses and with open spina bifida (myelomeningocele and rachischisis) at 26 weeks' gestation. The TVOL (delimitation of five cross-sectional areas of the middle portion of the limb) was evaluated, as well as the subjective assessment of hypotrophy and lower limb movement. RESULTS: Thirty-one fetuses with open spina bifida, 21 with myelomeningocele and 10 with rachischisis, and 51 normal fetuses were included. There were no significant differences in the TVOL between normal and spina bifida fetuses (p = 0.623), as well as between normal fetuses, with myelomeningocele and with rachischisis (p = 0.148). There was no significant difference in the TVOL of fetuses with spina bifida with or without lower limb hypotrophy (p = 0.148). Fetuses with spina bifida and with lower limb movement had higher TVOL values than fetuses without lower limb movement (p = 0.002). CONCLUSION: There were no significant differences in the TVOL measurement of normal and spina bifida fetuses (rachischisis and myelomeningocele). Fetuses with spina bifida without spontaneous movement of the lower limbs had lower TVOL values.

Measurement of the Area and Circumference of the Leg: Preliminary Results of a New Method for Estimating Leg Muscle Trophism in Fetuses With Open Lumbosacral Spina Bifida.

OBJECTIVE: To standardize a new technique to evaluate the fetal leg muscle trophism by measuring the area and circumference, and comparing this technique between normal and fetuses with open lumbosacral spina bifida (SB). METHODS: Observational cross-sectional study was carried out on pregnant women with 26 weeks who were divided into two groups: Group I-fetuses with diagnosis of open lumbosacral SB; Group II-normal fetuses (control). In fetuses with SB, subjective evaluation of the lower limbs was performed (muscle echogenicity and leg movements). To estimate the leg muscle trophism, the measurement of the area and circumference of the leg were standardized, and the reproducibility of this method was performed. RESULTS: Thirty-one fetuses with open lumbosacral SB and 51 normal fetuses were evaluated. The measurements of the area and circumference of the leg proved to be highly reproducible (intraclass correlation coefficient-ICC > 0.95). The leg area and circumference measurements were statistically lower in the SB group than in the control group (p < .001). When subjective ultrasound assessment demonstrated hypotrophy of the lower limbs, the measurements of the area and circumference of the leg were statistically lower when compared to normal fetuses (p < .001). Fetuses with open SB with abnormal lower limb movements had lower measurements of the area and circumference of the leg than fetuses with normal movements (p < .001). CONCLUSION: A new technique for estimating fetal leg muscle trophism was standardized, which proved to be highly reproducible and was able to show the difference between normal and fetuses with SB.

Cerebellar herniation demonstrated by the occipitum-dens line: Ultrasonography assessment of normal fetuses, fetuses with myelomeningocele, and fetuses that underwent antenatal myelomeningocele surgery.

OBJECTIVE: To establish a method to quantify the position of the cerebellum by ultrasonography in normal fetuses, fetuses with myelomeningocele (MMC), and fetuses that underwent in utero MMC repair. METHODS: Reference points identifiable on ultrasound were established. The basilar portion of the occipital bone and upper portion of the odontoid process were considered as the external and internal limits, respectively, of the level zero of a line that was designated the occipitum-dens line (ODL). Eighty-three normal fetuses were assessed 1 occasion (cross-sectional study) in addition to 25 fetuses with MMC and 25 fetuses that underwent in utero MMC repair. The groups were compared using analysis of variance or the Kruskal-Wallis test. The intraclass correlation coefficient (ICC) was used to determine intra- and interobserver reproducibility. RESULTS: The analysis of ODL indicated that all normal fetuses had the cerebellar tonsil above level zero at a mean distance of 2.8 ± 1.1 mm (P = 0.125). The fetuses with MMC had the cerebellar tonsil below level zero, except in 2 cases of myelocystocele. All the fetuses that underwent in utero MMC repair exhibited regression of the cerebellar herniation (0.5 mm per week, P < 0.005). Herniation increased gradually (1.0 mm per week, P < 0.005) in fetuses that did not undergo MMC repair. ICC indicated good intra- and interobserver reproducibility (0.996 and 0.983, respectively). CONCLUSION: The reference points for ODL may be used to assess cerebellar height. ODL allowed the demonstration of the regression of cerebellar herniation in fetuses that underwent in utero MMC repair.

Fetal modified left myocardial performance index monitoring during open surgery for myelomeningocele repair.

OBJECTIVE: Fetal hemodynamic changes have already been described during open myelomeningocele repair. This study aimed to access fetal myocardial performance index (MPI) during this high-complexity surgery. METHODS: Open myelomeningocele repair was performed in 37 fetuses between the 24th and 27th week of gestation. MPI was calculated at specific periods: pre-anesthesia, postanesthesia, neurosurgery (early skin manipulation, spinal cord releasing, and sintesis), and end of surgery. Mean ± standard deviation (SD) of MPI and its related times-isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and ejection time (ET)-was determined for each period. Analysis of variance (ANOVA) with repeated measures was used to assess differences among these periods. Tukey multiple comparison times test compared global surgery stages. RESULTS: The mean of MPI in the specific time points was 0.32, 0.32, 0.34, 0.48, 0.36, and 0.32, respectively (P < .001). In the two-tailed comparison times, neurosurgery stage presents MPI highest levels, especially on stage 3b (early skin manipulation and spinal cord releasing) related to ICT and IRT rising and ET decreased levels. CONCLUSION: Fetal global cardiac function is altered during the open myelomeningocele repair. The neurosurgery stage represents the critical phase of the procedure.

Fetal Heart Rate Monitoring during Intrauterine Open Surgery for Myelomeningocele Repair.

OBJECTIVE: The aim of this study was to assess fetal hemodynamics during intrauterine open surgery for myelomeningocele (MMC) repair by describing fetal heart rate (FHR) monitoring in detail related to each part of the procedure. METHODS: A study was performed with 57 fetuses submitted to intrauterine MMC repair between the 24th and 27th week of gestation. Evaluations of FHR were made in specific periods: before anesthesia, after anesthesia, at the beginning of laparotomy, during uterus abdominal withdrawal, hysterotomy, neurosurgery (before incision, during early skin manipulation, spinal cord releasing, and at the end of neurosurgery), abdominal cavity reintroduction, and abdominal closure, and at the end of surgery. Means ± standard deviations of FHR were established for each period, and analysis of variance with repeated measures was used to assess differences between these periods. The mean differences were assessed with 95% confidence intervals and were analyzed by Tukey's multiple comparison test. RESULTS: The mean FHR during the specific periods mentioned above was 140.2, 140, 139.2, 138.8, 135.1, 133.9, 123.1, 134.0, 134.5, 137.9, and 139.9 bpm, respectively (p < 0.0001). Comparing the different periods, the highest frequencies were observed in the initial and final moments. The neurosurgery stage presents lower frequencies, especially during the release of the spinal cord. CONCLUSION: FHR monitoring revealed interesting findings in terms of physiological fetal changes during MMC repair, especially during neurosurgery, which was the most critical period.

The occipitum-dens line: the purpose of a new ultrasonographic landmark in the evaluation of the relationship between the foetal posterior fossa structures and foramen magnum.

PURPOSE: The aims of this study were to describe a new ultrasonographic technique to assess the normal level of the cerebellum and the brainstem in the posterior fossa in normal foetuses and to compare in pathologic cases. METHODS: We propose a new line cross between the dens cervical and the inferior portion of occipitum (occipitum-dens line-ODL). In a cross-sectional study, a single observer with experience in foetal neurosonography evaluated 54 foetuses (40 normal and 14 with open neural tube defect) between 20 and 28 weeks of gestation. The reference points for the ODL are principally the lower portion of the occipital bone (occipitum) and odontoid process of the second cervical vertebra (dens). The line was considered the level zero (near level of foramen magnum). Structures above it had a positive measurement and below it had a negative measurement. RESULTS: Moreover, in most foetuses with open neural tube defect (93 %), the end portion of cerebellum was below the ODL associated with different degrees of ventriculomegaly. CONCLUSION: The proposed innovation aims to bring to the ultrasound the most likely anatomical parameters of evaluation in normal foetuses and in foetuses with spinal dysraphism.

Reference intervals for fetal heart volume from 3-dimensional sonography using the extended imaging virtual organ computer-aided analysis method at gestational ages of 20 to 34 weeks.

OBJECTIVES: The purpose of this study was to establish the reference range for fetal heart volume from 3-dimensional (3D) sonography using the extended imaging virtual organ computer-aided analysis method. METHODS: The fetal heart volume was measured in 303 normal singleton pregnancies at gestational ages of 20 to 34 weeks using 3D sonography. The extended imaging virtual organ computer-aided analysis method was used to obtain a sequence of 10 parallel symmetric sections through the heart, according to examiner-determined limits (the apex at one extremity and the connection to the great vessels at the other). Heart contours were drawn manually in all sections to obtain the 3D volume measurement, which was provided automatically by the software. Normal z scores and percentile reference ranges for each gestational age were constructed. RESULTS: The fetal heart volume increased with gestational age. The mean values were 3.09 mL at 20 weeks, 9.18 mL at 26 weeks, and 24.89 mL at 34 weeks, according to the following formulas: fetal heart volume (mL) = 18.0076 - 2.1005 × gestational age + 0.0677 × gestational age2 (R(2) = 0.922); and SD (mL) = (4.5038 - 0.4281 × gestational age + 0.0114 × gestational age2) × âˆš1.495808 (R(2) = 0.922). CONCLUSIONS: A reference range for fetal heart volume using the 3D sonographic extended imaging virtual organ computer-aided analysis method at gestational ages of 20 to 34 weeks was established.

Prediction of Lung Maturity in Fetuses with Growth Restriction through Quantitative Ultrasound Analysis.

The present study aimed to evaluate the performance of QuantusFLM software, which performs quantitative analysis of lung tissue texture through ultrasound images, in predicting lung maturity in fetal growth restriction (FGR). We included patients with singleton gestations between 34 and 38 6/7 wk and divided them into two groups: FGR and control (appropriate for gestational age [AGA]). The images were captured by ultrasound according to a specific protocol up to 48 h before delivery and analyzed with QuantusFLM software. The main clinical outcome evaluated was lung maturity (i.e., the absence of neonatal respiratory morbidity). We included 111 patients; one was excluded because of low image quality, leaving 55 patients in each group. The FGR group had a lower birth weight (2207 g vs. 2891 g, p < 0.001) and a longer stay in the neonatal intensive care unit (NICU) (10 d vs. 5 d, p = 0.043). QuantusFLM software was able to predict lung maturity in FGR with accuracy, sensitivity, specificity and positive and negative predictive values of 94.5%, 96.2%, 50%, 98.1% and 33.3%, respectively. QuantusFLM had good accuracy in predicting lung maturity in FGR with reliability in identifying pulmonary maturity.

Morphological evaluation of lateral ventricles of fetuses with ventriculomegaly by three-dimensional ultrasonography and magnetic resonance imaging: correlation with etiology.

PURPOSE: To evaluate morphology of lateral ventricles of ventriculomegaly/hydrocephaly fetuses using 3D-sonography by virtual organ computer-aided analysis (VOCAL) technique and magnetic resonance imaging (MRI) and verify morphologic patterns related to etiology. METHODS: Seventeen fetuses presenting with ventricular enlargement (atria > 10 mm) were evaluated. 3D datasets were acquired from a coronal reference plane and post-processed by the rotational imaging using VOCAL 30°. MRI study was analyzed in the three plans in all sequences. Morphologic aspects such as global shape, anterior, posterior and inferior horn characteristics, wall irregularities and deformities were analyzed and related to etiology factor. RESULTS: Twenty-nine percent of the cases were secondary to Arnold-Chiari syndrome and presented with global dilation of the three-horns. Cases related to aqueduct stenosis presented with ependymal rupture and wall irregularities in advanced cases. Corpus callosum agenesis cases presented with small ventricular volumes, thin shape, normal or slightly enlarged anterior and inferior horns with dilation restricted to posterior horn. Cases related to trisomy 18 and cytomegalovirus presented irregular ventricular walls associated with anomalous ventricular shapes, suggesting parenchymal destruction. CONCLUSION: Ventricular morphology evaluation gives important information on etiology of ventricular enlargement, supporting prognosis prediction and decision making process of the affected fetuses and their families.

Reliability and validity of in vitro volume calculations by 3-dimensional ultrasonography using the multiplanar, virtual organ computer-aided analysis (VOCAL), and extended imaging VOCAL methods.

OBJECTIVE: The purpose of this study was to assess the reliability and validity of in vitro volume calculations by 3-dimensional ultrasonography. METHODS: This observational study was performed by 2 examiners to obtain volumes of 3 objects of different shapes and sizes filled with ultrasound gel and immersed in water. The examiners used the multiplanar (5-mm interval), virtual organ computer-aided analysis (VOCAL, 30 degrees) and extended imaging (XI) VOCAL (5, 10, 15, and 20 planes) methods to estimate the volumes of each object. A paired Student t test (P) and intraclass correlation coefficients (ICCs) were used to assess reproducibility of the methods. Validity was assessed comparing the percent differences between the estimated and the real volumes using the P value, mean differences, and ICC for each method. RESULTS: All methods were highly reliable and valid. There were no significant differences in interobserver variability; there was a strong interobserver correlation. There were no significant differences in the percent differences between the estimated and real volumes of the objects using the 3 methods. The XI VOCAL method was superior to the multiplanar and VOCAL methods in the measurement of irregularly shaped objects. The XI VOCAL method with 10 planes estimated volumes closest to the real volumes. CONCLUSIONS: All 3 methods were reliable and valid; however, XI VOCAL was superior to the other methods in the measurement of irregularly shaped objects.

Prenatal diagnosis of closed spina bifida: multicenter case series and review of the literature.

Objective: Closed spina bifida (CSB) is an abnormality of the posterior arch formation in which the defect is covered by the skin, without protrusion of nervous tissue. The prenatal diagnosis of CSB is very difficult, rarely diagnosed antenatally.Methods: We present a multicenter case series of six prenatal diagnosis of CSB using two-dimensional (2D) ultrasonography complemented with three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). All cases of prenatal diagnosis of CSB were confirmed in the postnatal period/termination of pregnancy by both clinical and/or imaging diagnosis (ultrasonography and MRI).Results: 2D ultrasonography allowed the prenatal diagnosis of six cases. We observed two cases of subcutaneous lipomas, two cases of meningoceles, one case of fibrolipomas, and one case of false-positive CSB (meningomyelocele). 3D ultrasonography using rendering mode was important in one case of meningocele (case# 3). Three cases were delivered at term and one of them was submitted to corrective surgery. All these three newborns were discharged from the hospital well and without neurologic signs. Termination of pregnancy was performed in three cases.Conclusion: During prenatal evaluation, detailed ultrasonographic assessment of the entire spine with the identification of the position and morphology of the conus medullaris and absence of cranial signs of spinal dysraphism are the most valuable sonographic clues for the diagnostic of the CSB.

Ultrasonographic evaluation of the fetal central nervous system: review of guidelines.

Central nervous system malformations constitute the second most common group of anomalies in fetuses. Such malformations have assumed clinical importance because of their association with high rates of perinatal morbidity and mortality. Therefore, it is extremely important to assess the fetal central nervous system during the prenatal period, in order to identify any changes in its development and thereby gain sufficient information to advise parents about pregnancy follow-up, options for fetal therapy, and the timing/type of delivery, as well as the postnatal treatment and prognosis. The objective of this review was to describe the ultrasonographic evaluation of the fetal central nervous system as per the guidelines of the International Society of Ultrasound in Obstetrics and Gynecology.

Malformações do sistema nervoso central são o segundo mais frequente grupo de anomalias que afetam o feto. Elas têm adquirido grande importância em razão da sua associação com altas taxas de morbidade e mortalidade perinatal. Além do mais, é extremamente importante avaliar o sistema nervoso central fetal durante o período pré-natal, de modo a se diagnosticar possíveis mudanças no desenvolvimento e aconselhar os casais sobre o seguimento da gestação, possibilidades terapêuticas fetais, tempo e tipo de parto, tratamento pós-natal e prognóstico. O objetivo desta revisão foi descrever a avaliação do sistema nervoso central fetal por meio das recomendações da International Society of Ultrasound in Obstetrics and Gynecology.

Fetal posterior fossa malformations: review of the current knowledge.

Ultrasound diagnosis of posterior fossa malformations in the prenatal period is a challenge, having major implications for the counseling and follow-up of pregnant women. The purpose of this study was to review aspects of the ultrasound evaluation of the fetal posterior fossa, as well as to describe the most relevant ultrasound findings of the main posterior fossa malformations that can affect the fetus in the prenatal period.

Fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome treatment: initial experience in tertiary reference center in Brazil.

OBJECTIVE: To evaluate the initial maternal and perinatal outcomes of fetoscopic laser photocoagulation for the treatment of twin-to-twin transfusion syndrome (TTTS) in a referral center in Brazil. METHODS: This prospective observational study analyzed 24 fetoscopic laser photocoagulation procedures at 18-26 weeks of gestation. TTTS severity was determined using the Quintero classification. Blood vessels that crossed the interamniotic membrane were nonselectively photocoagulated. The χ2 test and Mann-Whitney U test were used for the statistical analysis. RESULTS: The mean (±standard deviation) age of pregnant women, gestational age at surgery, surgical time, gestational age at birth, and newborn weight were 32.2±4.1 years, 20.7±2.9 weeks, 51.8±16.7 minutes, 30.5±4.1 weeks, and 1,531.0±773.1 g, respectively. Using the Quintero classification, there was a higher percentage of cases in stage III (54.2%), followed by stages IV (20.8%), II (16.7%), and I (8.3%). Ten (41.7%) donor fetuses died and 14 (58.3%) donor fetuses survived until the end of gestation. Placental insertion location (anterior vs. posterior) did not affect the incidence of iatrogenic septostomy, surface bleeding, and premature rupture of membranes until the end of gestation. The death rate of donor and recipient fetuses before 24th gestational week increased with severity of TTTS. CONCLUSION: The maternal and perinatal outcomes resulting from the implementation of a new minimally invasive surgical technique are in line with those obtained in major centers worldwide, considering the learning curves and infrastructures.

New technique for assessing fetal heart growth using three-dimensional ultrasonography: description of the technique and reference curves.

OBJECTIVE: To describe a new technique for assessing fetal growth using three-dimensional ultrasonography (3DUS) using the extended imaging virtual organ computer-aided analysis (XI VOCAL) software and its respective reference curves. METHODS: We conducted a cross-sectional study on 303 normal singleton pregnancies between their 20th and 34th weeks. To assess fetal heart growth, we used the XI VOCAL software with 10 planes in which the reference lines (beginning and end) were placed at the cardiac apex, the output level of the vessels and the base above the diaphragm, respectively. To assess the correlation between distance and interval, polynomial regressions were performed with adjustments using the coefficient of determination (R(2)). To assess the inter-observer reproducibility, we used the intraclass correlation coefficient (ICC). RESULTS: The mean distance between the apex and the base of the fetal heart ranged from 14.41 ± 1.24 mm to 26.24 ± 2.62 mm between the 20th and 34th weeks, respectively. The mean interval between the apex and the base of the fetal heart ranged from 1.56 ± 0.13 mm and 2.94 ± 0.30 mm between the 20th and 34th weeks, respectively. We observed good correlation of distance and interval with the gestational age, with R(2) = 0.73 and 0.74, respectively. We observed a good inter-observer to the interval and distance with ICC = 0.983 and 0.996, respectively. CONCLUSION: We described a new technique for assessing fetal heart growth using 3DUS and determined reference curves for the distance and interval between the 20th and 34th weeks of pregnancy.

Agnathia-otocephaly: prenatal diagnosis by two- and three-dimensional ultrasound and magnetic resonance imaging. Case report.

A case of prenatally diagnosed otocephaly is reported. Otocephaly is an extremely rare malformation characterized by absence or hypoplasia of the mandible and abnormal horizontal position of the ears. 2D ultrasound performed at 25 weeks of gestation revealed agnathia, proboscis and hypotelorism. 3D ultrasound (rendering mode) and magnetic resonance imaging were used to evaluate the facial features, and were essential for characterization of facial malformations in otocephaly and for the demonstration and correct prenatal counseling of the couple.