Biocellulose patch technique for fetoscopic repair of open spina bifida in twin pregnancy.

OBJECTIVES: Twin pregnancy is currently an exclusion criterion for prenatal repair of open spina bifida (OSB). The main objective of this study was to report on our experience of treating twin pregnancies with OSB using the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique. We also discuss reconsideration of the current exclusion criteria for fetal OSB repair. METHODS: Eight fetuses with OSB from seven twin pregnancies underwent successful prenatal repair. Six pregnancies were dichorionic diamniotic with only one twin affected, and one was monochorionic diamniotic with both twins affected. Percutaneous fetoscopy was performed under CO2 insufflation of the sac of the affected twin. Neurosurgical repair was performed using a biocellulose patch to protect the placode, with the skin sutured to hold the patch in place, with or without a myofascial flap. Neurodevelopment was assessed using the pediatric evaluation of disability inventory scale in babies older than 6 months of adjusted age, whereas the Alberta scale was used for babies younger than 6 months of adjusted age. RESULTS: All 14 fetuses were liveborn and none required additional repair. Gestational age at surgery ranged from 27.3 to 31.1 weeks, and gestational age at birth ranged from 31.6 to 36.0 weeks. Four out of eight affected twins developed sepsis, but had a good recovery. No sequela of prematurity was found in any of the unaffected twins. Short-term neurodevelopment was normal in all evaluated unaffected twins (5/5) and in all but one affected twins (7/8). In the affected group, only one baby required ventriculoperitoneal shunt placement. CONCLUSIONS: Prematurity is frequent after fetal surgery, and the risk is increased in twin pregnancy. Nevertheless, prenatal surgery using the SAFER technique is feasible, with low risk to both twins and their mother when performed by a highly experienced team. Long-term cognitive assessment of the unaffected twin is needed. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Learning curves of open and endoscopic fetal spina bifida closure: systematic review and meta-analysis.

OBJECTIVE: The Management of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida aperta (SBA). Recently developed alternative techniques may reduce maternal risks without compromising the fetal neuroprotective effects. The aim of this systematic review was to assess the learning curve (LC) of different fetal SBA closure techniques. METHODS: MEDLINE, Web of Science, EMBASE, Scopus and Cochrane databases and the gray literature were searched to identify relevant articles on fetal surgery for SBA, without language restriction, published between January 1980 and October 2018. Identified studies were reviewed systematically and those reporting all consecutive procedures and with postnatal follow-up ≥ 12 months were selected. Studies were included only if they reported outcome variables necessary to measure the LC, as defined by fetal safety and efficacy. Two authors independently retrieved data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effects model when heterogeneous. To measure the LC, we used two complementary methods. In the group-splitting method, competency was defined when the procedure provided results comparable to those in the MOMS trial for 12 outcome variables representing the immediate surgical outcome, short-term neonatal neuroprotection and long-term neuroprotection at ≥ 12 months of age. Then, when raw patient data were available, we performed cumulative sum analysis based on a composite binary outcome defining successful surgery. The composite outcome combined four clinically relevant variables for safety (absence of extreme preterm delivery < 30 weeks, absence of fetal death ≤ 7 days after surgery) and efficacy (reversal of hindbrain herniation and absence of any neonatal treatment of dehiscence or cerebrospinal fluid leakage at the closure site). RESULTS: Of 6024 search results, 17 (0.3%) studies were included, all of which had low, moderate or unclear risk of bias. Fetal SBA closure was performed using standard hysterotomy (11 studies), mini-hysterotomy (one study) or fetoscopy by either exteriorized-uterus single-layer closure (one study), percutaneous single-layer closure (three studies) or percutaneous two-layer closure (one study). Only outcomes for standard hysterotomy could be meta-analyzed. Overall, outcomes improved significantly with experience. Competency was reached after 35 consecutive cases for standard hysterotomy and was predicted to be achieved after ≥ 57 cases for mini-hysterotomy and ≥ 56 for percutaneous two-layer fetoscopy. For percutaneous and exteriorized-uterus single-layer fetoscopy, competency was not reached in the 81 and 28 cases available for analysis, respectively, and LC prediction analysis could not be performed. CONCLUSIONS: The number of cases operated is correlated with the outcome of fetal SBA closure, and the number of operated cases required to reach competency ranges from 35 for standard hysterotomy to ≥ 56-57 for minimally invasive modifications. Our observations provide important information for institutions looking to establish a new fetal center, develop a new fetal surgery technique or train their team, and inform referring clinicians, potential patients and third parties. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Curvas de aprendizaje del cierre de la espina bífida fetal mediante cirugía abierta y endoscópica: revisión sistemática y metaanálisis OBJETIVO: El ensayo del Estudio sobre la Gestión del Mielomeningocele (MOMS, por sus siglas en inglés) demostró la seguridad y eficacia de la cirugía fetal abierta para la espina bífida aperta (EBA). Las técnicas alternativas recientemente desarrolladas pueden reducir los riesgos de la madre sin comprometer los efectos neuroprotectores del feto. El objetivo de esta revisión sistemática fue evaluar la curva de aprendizaje (CA) de diferentes técnicas de cierre de la EBA fetal. MÉTODOS: Se realizaron búsquedas en las bases de datos de MEDLINE, Web of Science, EMBASE, Scopus y Cochrane, así como en la literatura gris, para identificar artículos relevantes sobre cirugía fetal para la EBA, sin restricción de idioma, publicados entre enero de 1980 y octubre de 2018. Se examinaron sistemáticamente los estudios identificados y se seleccionaron los que informaban de todos los procedimientos consecutivos y con seguimiento postnatal ≥12 meses. Los estudios se incluyeron sólo si informaban sobre las variables de resultado necesarias para medir la CA, definidas por la seguridad y la eficacia para el feto. Dos autores recuperaron los datos de forma independiente, evaluaron la calidad de los estudios y clasificaron las observaciones en bloques de 30 pacientes. Para el metaanálisis, los datos se agruparon mediante un modelo de efectos aleatorios cuando fueron heterogéneos. Para medir la CA, se usaron dos métodos complementarios. En el método de división de grupos, la competencia se definió cuando el procedimiento proporcionó resultados comparables a los del ensayo MOMS para 12 variables de resultados que representaban el resultado quirúrgico inmediato, la neuroprotección neonatal a corto plazo y la neuroprotección a largo plazo a ≥12 meses de edad. Luego, cuando se dispuso de los datos brutos de los pacientes, se realizó un análisis de suma acumulada basado en un resultado binario compuesto que definió el éxito de la cirugía. El resultado compuesto combinó cuatro variables clínicamente relevantes en cuanto a la seguridad (ausencia de parto pretérmino extremo <30 semanas; ausencia de muerte fetal a ≤7 días después de la cirugía) y eficacia (reducción de la hernia del rombencéfalo y ausencia de cualquier tratamiento neonatal de dehiscencia o derrame de líquido cefalorraquídeo en el lugar del cierre). RESULTADOS: De los 6024 resultados de la búsqueda, se incluyeron 17 (0,3%) estudios, todos ellos con un riesgo de sesgo bajo, moderado o incierto. El cierre de la EBA fetal se realizó mediante histerotomía estándar (11 estudios), mini histerotomía (un estudio) o fetoscopia, ya fuera mediante el cierre exteriorizado del útero de una sola capa (un estudio), el cierre percutáneo de una sola capa (tres estudios) o el cierre percutáneo de dos capas (un estudio). Sólo se pudieron metaanalizar los resultados de la histerotomía estándar. En general, los resultados mejoraron significativamente con la experiencia. Se alcanzó la competencia después de 35 casos consecutivos para la histerotomía estándar y se predijo que se alcanzaría después de ≥57 casos para la mini histerotomía y ≥56 para la fetoscopia percutánea de dos capas. En el caso de las fetoscopias percutánea y exteriorizada del útero de una sola capa, no se alcanzó la competencia en los 81 y 28 casos disponibles para el análisis, respectivamente, y no se pudo realizar el análisis de predicción de la CA. CONCLUSIONES: El número de casos operados está correlacionado con el resultado del cierre de la EBA fetal, y el número de casos operados necesarios para alcanzar la competencia estuvo entre 35 para la histerotomía estándar y ≥56-57 para las operaciones con mínima agresividad. Las observaciones realizadas proporcionan información importante para las instituciones que buscan establecer un nuevo centro fetal, desarrollar una nueva técnica de cirugía fetal o entrenar a su equipo, e informar a los médicos que remiten a especialistas a los posibles pacientes y a terceros. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Percutaneous fetoscopic closure of large open spina bifida using a bilaminar skin substitute.

OBJECTIVE: We have described previously our percutaneous fetoscopic technique for the treatment of open spina bifida (OSB). However, approximately 20-30% of OSB defects are too large to allow primary skin closure. Here we describe a modification of our standard technique using a bilaminar skin substitute to allow closure of large spinal defects. The aim of this study was to report our clinical experience with the use of a bilaminar skin substitute and a percutaneous fetoscopic technique for the prenatal closure of large OSB defects. METHODS: Surgery was performed between 24.0 and 28.9 gestational weeks with the woman under general anesthesia, using an entirely percutaneous fetoscopic approach with partial carbon dioxide insufflation of the uterine cavity, as described previously. If there was enough skin to be sutured in the midline, only a biocellulose patch was placed over the placode (single-patch group). In cases in which skin approximation was not possible, a bilaminar skin substitute (two layers: one silicone and one dermal matrix) was placed over the biocellulose patch and sutured to the skin edges (two-patch group). The surgical site was assessed at birth, and long-term follow-up was carried out. RESULTS: Percutaneous fetoscopic OSB repair was attempted in 47 consecutive fetuses, but surgery could not be completed in two. Preterm prelabor rupture of membranes (PPROM) occurred in 36 of the 45 (80%) cases which formed the study group, and the mean gestational age at delivery was 32.8 ± 2.5 weeks. A bilaminar skin substitute was required in 13/45 (29%) cases; in the remaining 32 cases, direct skin-to-skin suture was feasible. There were 12 cases of myeloschisis, of which 10 were in the two-patch group. In all cases, the skin substitute was located at the surgical site at birth. In five of the 13 (38.5%) cases in the two-patch group, additional postnatal repair was needed. In the remaining cases, the silicone layer detached spontaneously from the dermal matrix (on average, 25 days after birth), and the lesion healed by secondary intention. The mean operating time was 193 (range, 83-450) min; it was significantly longer in cases requiring the bilaminar skin substitute (additional 42 min on average), although the two-patch group had similar PPROM rate and gestational age at delivery compared with the single-patch group. Complete reversal of hindbrain herniation occurred in 68% of the 28 single-patch cases and 33% of the 12 two-patch cases with this information available (P < 0.05). In four cases there was no reversal; half of these occurred in myeloschisis cases. CONCLUSIONS: Large OSB defects may be treated successfully in utero using a bilaminar skin substitute over a biocellulose patch through an entirely percutaneous approach. Although the operating time is longer, surgical outcome is similar to that in cases closed primarily. Cases with myeloschisis seem to have a worse prognosis than do those with myelomeningocele. PPROM and preterm birth continue to be a challenge. Further experience is needed to assess the risks and benefits of this technique for the management of large OSB defects. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Uterine artery Doppler patterns in abdominal pregnancy.

Changes in the uterine artery blood flow waveform during pregnancy have been the subject of several studies and are frequently attributed to trophoblastic invasion of the myometrium. We report on a case of a third-trimester abdominal pregnancy in which we performed Doppler velocimetry of the uterine arteries and observed low-resistance flow and absence of notching bilaterally. During the 29th week of gestation, there was an increase in umbilical artery resistance and a decrease in the middle cerebral artery resistance, so we chose to deliver the baby at that stage. The patient was discharged from hospital 7 days following delivery and the child was discharged having gained the necessary weight. Our findings suggest that modification of the uterine artery waveform may occur independently of trophoblast invasion of the spiral arteries. Other theories that may explain the changes in the uterine artery waveform during pregnancy are discussed.

Nuchal translucency: an ultrasound marker for fetal chromosomal abnormalities.

CONTEXT: The literature shows an association between several ultrasound markers and chromosome abnormality. Among these, measurement of nuchal translucency has been indicated as a screening method for aneuploidy. The trisomy of chromosome 21 has been most evaluated. OBJECTIVE: To define the best fixed cutoff point for nuchal translucency, with the assistance of the ROC curve, and its accuracy in screening all fetal aneuploidy and trisomy 21 in a South American population. TYPE OF STUDY: Validation of a diagnostic test. SETTING: This study was carried out at the State University of Campinas, Campinas, Brazil. PARTICIPANTS: 230 patients examined by ultrasound at two tertiary-level private centers, at 10 to 14 weeks of gestation. DIAGNOSTIC TEST: The participants consisted of all those patients who had undergone ultrasound imaging at 10 to 14 weeks of gestation to measure nuchal translucency and who had had the fetal or neonatal karyotype identified. MAIN MEASUREMENTS: Maternal age, gestational age, nuchal translucency measurement, fetal or neonatal karyotype. RESULTS: Prevalence of chromosomal defects - 10 %; mean age - 35.8 years; mean gestational age - 12 weeks and 2 days; nuchal translucency (NT) thickness - 2.18 mm. The best balance between sensitivity and specificity were values that were equal to or higher than 2.5 mm for overall chromosomal abnormalities as well as for the isolated trisomy 21. The sensitivity for overall chromosomal abnormalities and trisomy 21 were 69.5 % and 75 %, respectively, and the positive likelihood ratios were 5.5 and 5.0, respectively. CONCLUSION: The measurement of nuchal translucency was found to be fairly accurate as an ultrasound marker for fetal abnormalities and measurements equal to or higher than 2.5 mm were the best fixed cutoff points.