Fetal surgery for open spina bifida

Abstract

Key content: Spina bifida is a congenital neurological condition with lifelong physical and mental effects.Open fetal repair of the spinal lesion has been shown to improve hindbrain herniation, ventriculoperitoneal shunting, independent mobility and bladder outcomes for the child and, despite an increased risk of prematurity, does not seem to increase the risk of neurodevelopmental impairment.Open fetal surgery is associated with maternal morbidity.Surgery at our institution is offered and performed according to internationally agreed criteria and protocols.Further evidence regarding long-term outcomes, fetoscopic repair and alternative techniques is awaited.

Learning objectives: To understand the clinical effects, potential prevention and prenatal diagnosis of spina bifida.To understand the rationale and evidence supporting the benefits and risks of fetal repair of open spina bifida.To understand the criteria defining those who are likely to benefit from fetal surgery.

Ethical issues: The concept of the fetus as a patient, and issues surrounding fetal death or the need for resuscitation during fetal surgery.The associated maternal morbidity in a procedure performed solely for the benefit of the fetus/child.The financial implications of new surgical treatments.

Keywords: fetal surgery; fetoscopy; myelomeningocele; prenatal; spina bifida.

Figure 1

Types of spina bifida. (a) normal situation, (b) spina bifida occulta, (c) myelomeningocele. Reproduced with permission from Universitair Ziekenhuis Leuven, Belgium.

Figure 2

Antenatal diagnosis of spina bifida. Spinal lesion seen in (a) sagittal plane, (b) transverse plane and (c) 3D reconstruction. (d) Transverse section of fetal brain demonstrating ‘lemon’‐shaped skull (yellow arrows), ‘banana’‐shaped cerebellum (green arrow) and hindbrain herniation (red arrows). Reproduced with permission from University College London Hospitals.

Figure 3

Open spina bifida repair technique. Step (a) shows untethering of the neural placode, followed by anatomical closure of the dura (b), myofascia (c) and skin (d). Reproduced with permission from Universitair Ziekenhuis Leuven, Belgium.

Figure 4

A case of myeloschisis. (a,b) Preoperative ultrasound findings of a relatively wide open lesion; (c) intraoperative images of the lesion prior to repair; (d) following closure of the dura and (e) application of a skin patch. Reproduced with permission from University College London Hospitals, London and Universitair Ziekenhuis Leuven, Belgium.

Figure 5

A case of myelomeningocele (same patient as Figure 2). (a) Preoperative findings of a covered lesion; (b) intraoperative images of the lesion prior to repair and (c) following skin closure. Reproduced with permission of University College London Hospitals and Universitair Ziekenhuis Leuven, Belgium.

Figure 6

Outpatient postoperative pathway. FMU = fetal medicine unit; MRI = magnetic resonance imaging; SROM = spontaneous rupture of membranes; US = ultrasound scan

Figure 7

Neonatal protocol following open fetal surgery for spina bifida. DMSA = dimercaptosuccinic acid radionuclide scan; MCUG = micturating cystourethrogram; MRI = magnetic resonance imaging; OFC = occipito‐frontal circumference; SCBU = special care baby unit; USS = ultrasound scan; VP = ventriculoperitoneal

Figure 8

Examples of neurosurgical repair techniques reported in fetoscopic spina bifida repair. (a) Single layer repair (skin sutured); (b) double layer repair (subcutaneous patch and skin suture); (c) patch coverage; (d) double patch repair. Reproduced with permission of the Universitair Ziekenhuis Leuven, Belgium.