gms | German Medical Science

Objective: Open spina bifida is generally compatible with postnatal life, although resulting neurological deterioration below level of defect may lead to inability to walk, anesthesia, and incontinence. Prenatal surgical repair has been practice in several specialized centers worldwide in the last 20 years (Europe 2007). Since 2011, MOMS study (Management Of Myelomeningocele Study) has demonstrated significant benefits for newborn in short and medium term, compared to postnatal surgery (40% reduction in shunts, Chiari malformation type 2 and a significant improvement in lower limb motor neurologic function), with no significant differences in urological function, having a higher incidence in preterm deliveries, increased postpartum uterine dehiscence, also. Surgical closure in the fetus is similar to postnatal, however, performed under strict criteria and protocols, important differences in technique, are key to good results.

In this article, we present aspects of 15 years’ experience in a reference center for fetal surgery in Medellin, Colombia.

Objective: Describe results and follow-up of fetal surgery performed in 48 patients with myelomeningocele, treated at Bolivarian Clinic of Medellin, Colombia and their motor functional evolution from first year of life.

Materials and Methods: This is an Interventional study, retrospective, case report series of patients treated from December 2002 to January 2017, in a specialized care institution. All pregnant women presented with preoperative evaluation by gynecology, obstetrics, fetal medicine, obstetric anesthesiology and neurosurgery specialists, being under prenatal surveillance with diagnosis of myelomeningocele by high-resolution obstetric ultrasound images and in some cases, gestational magnetic resonance. During surgery, women were treated with best pharmacological treatment of uterus inhibition available (nifedipine, atosiban, magnesium sulfate, progesterone) and strict fetal monitoring. Maternal sociodemographic (schooling and occupation, residential area, social security, age, height and weight), history of previous deliveries, cesarean sections and abortions, gestational age at intervention at birth, amnioinfusion fluid volume, time of uterus inhibition, description of maternal complications (pulmonary edema, abruptio of placenta, premature rupture of membranes, dehiscence of uterorrafia). Fetal variables included initial and final vertebral level of defect, diameter, neurosurgery time, need for collagen patch, size of brain ventricles, presence of brain abnormalities and hydrocephalus. Motor capacity monitored for walking up to 5 years of age. No cognitive ability or mental development assessed.

Results: 48 pregnant women diagnosed with fetal myelomeningocele, with a mean maternal age of 29 years, 54% active in the labor market, 41% with a professional education and 79% residing in an urban area were included. The disease was present during the first gestation in 48%. There was a history of previous uterine surgery in 20.8% of pregnant women.The diagnosis of myelomeningocele performed on average at 21.8 gestational weeks. Fetal surgery performed on average at 23.7 weeks. Only two patients required gestational magnetic resonance. There were maternal complications such as pulmonary edema (8.3%), abruptio placenta (12.5%) and premature rupture of ovular membranes (54.2%), the latter being on average at 30 weeks of gestation. There were no postoperative uterine ruptures, suture dehiscence at the time of cesarean section was 4.2%, oligoamnios considered in 20.8%. The region most affected by myelomeningocele was lumbar and sacral (95%), with L4 being upper level (26%) and S2 lower (43%), most frequent. Mean diameter of the defect was 34.3 mm. Fetuses presented comorbidities, hydronephrosis (4.2%), plantar deformity (16.7%), one patient had agenesis of the corpus callosum, but no major cranial alterations was seen. The uterotomy-uterorrhaphy surgical time was 2 hours, with an average myelomeningocele repair time of 33.8 min. The average amniotransfusion volume was 266 ml. A collagen patch was required in 5 patients. The average age at birth was 32.1 weeks, with an average weight of 1825 grams. There was a subjective improvement of Chiari type 2 malformation in all patients. Among early postnatal complications, respiratory distress syndrome (16.7%), sepsis (4.2%), urinary tract infection (12.5%). The intraoperative and perinatal mortality of the fetus was 8.3%. During the postnatal follow-up, only 1 patient required endoscopic ventriculostomy; they presented paraplegia (67%), paraparesis (16%), strength conservation to achieve standing and effective walking with only sphincter control alteration (17%).

Discussion: This study is the largest and longest series of cases in our region, results to date are in chord with previous reported in series worldwide, with similar results, showing a marked effect on decrease in requirement in shunt procedures, improvement of Chiari type 2 malformation, and similar motor neurological lower limb response, maternal morbidity and fetal mortality rate, too. Open fetal surgery for the treatment of myelomeningocele finds increasingly better defined benefits when compared to postnatal correction, definitely affects a child's better quality of life by reducing need for shunt surgeries, however, despite lack of impact in urinary function and greater preterm birth and maternal morbidity. Fetal endoscopic surgery interventions attempt to reduce these complications, but are in process of being refined.

Conclusion: Fetal surgery for myelomeningocele correction has advantages compared to postnatal correction, even though incidence of preterm delivery increases. Requires a multidisciplinary group with experience, strict time control and surgical technique, good results can be obtain with procedure, with low rates of morbidity and global mortality. We suggest considering it as first option.

Key words (DeCS): fetal surgery, myelomeningocele, shunt, hydrocephalus, Chiari malformation, lumbar, dural sac

Palabras clave (DeCS): cirugía fetal, mielomeningocele, derivación, hidrocefalia, malformación de Chiari, lumbar, saco dural

Note: The authors declare no conflicts of interest.