The closure of the skin defect in myelomeningocele (MMC) repair is an essential step that determines the quality of the surgical result. The success of surgical results is related to the decision to use the most suitable techniques, namely flaps or primary closure.
In cases of myelomeningocele, some prefer to place the shunt and close the defect in the same procedure, it reduces the risks inherent to exposure to anesthesia, reduces hospital stay, and related costs. If there is a suspicious of infection, they do not place the shunt on the same procedure 1).
Prenatal therapeutic strategies that interrupt progressive pathological processes offer an appealing approach for treatment of MMC. However, a thorough understanding of pathological progression of MMC is mandatory for appropriate treatment to be rendered 2).
Closure of the defect.
see MOMS Trial.
A prospective study of Zarutskie et al., from the Baylor College of Medicine, Texas Children’s Hospital, Lucile Packard Children’s Hospital Stanfordfrom fetuses diagnosed with open neural tube defect that had in-utero myelomeningocele repair between April 2014 and April 2016. Independent variables were collected from four chronological sets of fetal images: pre-surgery ultrasound, pre-surgery MRI, 6-week post-surgery MRI and pre-delivery ultrasound. The following independent variables were collected from all image sets unless otherwise noted: gestational age, head circumference, mean ventricular width, ventricular volume (VV, MRI only), hindbrain herniation (HBH) score (MRI only), and level of lesion, defined as the upper bony spinal defect (pre-surgery US). Based on these measurements, additional variables were defined and calculated including change in degree of HBH, ventricular width growth (mm/week), and ventricular volume growth (ml/week). The need for hydrocephalus HT (by either ventriculoperitoneal shunt or endoscopic third ventriculostomy and choroid plexus cauterization (ETV-CPC)) was determined by a pediatric neurosurgeon using clinical and radiographic criteria; a secondary analysis was performed using the MOMS trial criteria for hydrocephalus. The predictive value of each parameter was assessed by ROC-curve and logistic regression analyses.
Fifty affected fetuses were included in the study, of which 32 underwent open hysterotomy and 18 fetoscopic repair. Two cases of neonatal death were excluded from the analysis. The mean gestational ages for the pre-surgery ultrasound, pre-surgery MRI, post-surgery MRI and pre-delivery ultrasound were 21.8 ± 2.1 weeks, 22.0 ±1.8 weeks, 30.4 ±1.6 weeks and 31.0 ±4.9 weeks, respectively. A total of 16 subjects required HT. Area under the curve (AUC) of predictive accuracy for HT showed that HBH grading on post-surgery MRI had the strongest predictive value (0.86; p<0.01), outperforming other predictors such as mean ventricular width on pre-surgery US (0.67; p=0.05), post-surgery MRI VV (0.73; p=0.03), MRI VV growth (0.79; p=0.01), change in HBH (0.82; p<0.01), and mean ventricular width on pre-delivery US (0.73; p=0.01). Other variables such as mean ventricular width on pre-surgery and post-surgery MRI, and ventricular growth assessment by MRI or US, had an AUC<0.7. Optimal cut-offs of the variables with the highest AUCs were evaluated to improve prediction. A combination of ventricular volume growth ≥ 2.02 ml/week and/or HBH of 3 on post-surgery MRI were the optimal cut-offs for the best prediction [OR: 42 (95% CI: 4 – 431), accuracy: 84%]. Logistic regression analyses also showed that persistence of severe HBH 6 weeks after surgery by MRI is one of the best predictors for HT [OR 39 (95% CI: 4 – 369), accuracy: 84%]. There was no significant change in the results when the MOMS trial criteria for hydrocephalus were used as the dependent variable 3).
Sanz-Cortés et al., described and compared placental and amniotic histology in women who underwent a fetoscopic myelomeningocele repair to those who underwent an open-hysterotomy myelomeningocele repair. Also, we intended to compare findings from both prenatal repair groups to age-matched control pregnant patients.
Placental and membrane histopathology from 43 prenatally repaired spina bifida cases (17 fetoscopic and 26 open) and 18 healthy controls were retrospectively assessed. Quantitative assessment of histopathology included apoptosis count, maternal and fetal underperfusion scores. Qualitative assessment included the detection of pigmented macrophages and/or signs of placental/amniotic inflammation. Associations between the duration of surgery or the duration of CO2 insufflation and quantitative histological parameters were tested.
Fetoscopic surgery cases did not show significant differences in any of the studied parameters when compared against controls. No differences were detected either when compared to open-repaired cases, except for lower proportion of pigmented laden macrophages in the fetoscopic group (11.8% vs 61.5% p<0.01). No associations between the duration of surgery or the duration of CO2 exposure and any of the quantitative histological parameters were detected.
These preliminary results support the lack of detrimental effects of the use of heated and humidified CO2 gas for uterine insufflation to fetal membranes and placenta 4).