Successful fetal surgery for spina bifida

Abstract

Spina bifida occurs in one of 2000 livebirths and leads to lifelong and devastating physical disabilities including paraplegia, hydrocephalus, incontinence, sexual dysfunction, skeletal deformations, and mental impairment.1Copp AJ Neural tube defects.Trends Neurosci. 1993; 16: 381-383Summary Full Text PDF PubMed Scopus (29) Google Scholar Compelling experimental evidence shows that the neurological deficit associated with open spina bifida is not entirely caused by the primary defect of neurulation, but rather is due to chronic mechanical injury and amniotic fluid-induced chemical trauma that progressively damages the exposed unprotected fetal neural tissue during gestation. Timely in-utero repair of spina bifida in fetal sheep stops the ongoing spinal cord destruction and “rescues” neurological function by the time of birth.2Meuli M Meuli-Simmen C Hutchins GM et al.In utero surgery rescues neurological function at birth in sheep with spina bifida.Nat Med. 1995; 1: 342-347Crossref PubMed Scopus (293) Google Scholar In late-gestation human fetuses and in neonates with spina bifida, the neural tissue elements show severe traumatic and degenerative alterations, or there is almost complete loss of neural tissue.3Meuli M Meuli-Simmen C Hutchins GM Sellar MJ Harrison MR Adzick NS The spinal cord lesion in human fetuses with myelomeningocele: implications for fetal surgery.J Pediatr Surg. 1997; 32: 448-452Summary Full Text PDF PubMed Scopus (167) Google Scholar Sonographic reports of human fetuses with very large spina bifida lesions and normal leg movements early in gestation imply that motor function is present initially and lost only later in gestation.4Korenromp MJ Van Good JD Bruinse HW Kriek R Early fetal leg movements in myelomeningocele.Lancet. 1986; i: 917-918Abstract Scopus (123) Google Scholar We report the first successful in-utero surgical repair of open spina bifida in an early-gestation fetus. A 27-year-old woman was referred for assessment of a 23-week gestation fetus with thoracolumbosacral spina bifida. The lesion was detected on a 20-week ultrasound done because of a raised maternal serum α-fetoprotein. Serial ultrasounds showed good leg movements, and karyotype by amniocentesis was normal. Ultrafast fetal magnetic resonance imaging revealed a spina bifida lesion extending from thoracic level 11 to sacral level 1, Arnold-Chiari type II malformation, and borderline hydrocephalus (the fetal lateral ventricles measured 10 mm). The mother declined pregnancy termination and consented to surgery. Maternal general anaesthesia provided fetal anaesthesia and uterine relaxation for open fetal surgery. A low transverse maternal laparotomy and vertical hysterotomy were performed.5Adzick NS Harrison MR Fetal surgical therapy.Lancet. 1994; 343: 897-902Abstract PubMed Scopus (133) Google Scholar The cystic membrane of the spina bifida lesion was excised, and skin flaps were developed laterally to close the defect and protect the developing spinal cord (figure). Because we were concerned about possible secondary hydrocephalus after the lesion was closed, cerebrospinal fluid shunt tubing was threaded up alongside the proximal spinal cord and the slit-valve end was brought out via a separate skin wound. Amniotic fluid was replaced with warmed lactated Ringer's solution and the uterine and laparotomy wounds were closed. Postoperatively, tocolysis was maintained with magnesium sulphate intravenous infusion and indometacin rectal suppositories, followed by terbutaline given by a subcutaneous pump. The mother was discharged from hospital 5 days postoperatively. At 30 weeks' gestation, preterm labour led to the delivery by caesarean section of a 1·3 kg baby boy who required a short period of ventilatory support. The mother recovered uneventfully. The shunt tubing was removed immediately after birth. The baby showed excellent left leg function except for absent plantar flexion of the foot (L5 level). A right club foot was present, but the baby had right hip and knee flexion and extension (L4 level). Postnatal magnetic resonance imaging confirmed that the repaired spina bifida lesion extended from T11 to S1 and revealed that the Arnold-Chiari type II malformation was no longer present and there was no hydrocephalus. He has met all developmental milestones at age 6 months, but long-term follow-up is needed. Neonates with thoracolumbar spina bifida are almost invariably paraplegic and have associated hydrocephalus that requires a lifelong shunt. This case shows that early gestation fetal surgical repair of severe spina bifida can save neurological function. By arresting the neural destruction, prenatal repair may also allow rearrangements of function due to the plasticity of the developing nervous system. In addition, the resolution of the Arnold-Chiari malformation after in-utero repair suggests that this brain malformation is a secondary consequence of spina bifida. In-utero spina bifida repair may thus obviate the complications of Arnold-Chiari malformation including the need for shunt procedures after birth.