Outcomes of Chiari Malformation III: A Review of Literature

Chiari III malformation in a neonate

Chiari malformation (CM) is a group of complex deformities of the posterior fossa and hindbrain, of which CMIII is the rarest. We report a term neonate, with an antenatal diagnosis of occipital encephalocele, who underwent resection of the encephalocele and ligation of vessels, with repair of a large scalp defect and dural reconstruction on day 4 of life. The parents of the child had been counselled for a guarded and poor prognosis on initial diagnosis. The child has had a good postoperative course without complications but suffers from cortical visual impairment and global developmental delay.

Treatment of Chiari III Malformation in Infant with 4K 3D ORBEYE Exoscope

Chiari malformation (CM)-III is the rarest anomaly among CMs.1 Treatment of choice is surgical repair,2 although poor outcome and postoperative mortality has been reported.3 Surgical timing is still debated.4,5 We present the case of a male infant with a prenatal diagnosis of encephalocele. Presentation was characterized by hemodynamic instability, horizontal nystagmus, and left shoulder dystocia due to caesarean section, with a 64 mm × 49 mm × 76 mm soft, fluctuant, and translucent suboccipital-cervical sac. Magnetic resonance imaging revealed a median occipital bone defect with the meningoencephalic sac communicating with the vermian cistern and the fourth ventricle, moderate hydrocephalus, reduction of the posterior cranial fossa volume, hypoplasia of cerebellar hemispheric, vermian structures, and corpus callosum hypoplasia. The patient underwent surgery on day 4 with the use of a 4K 3D ORBEYE exoscope (Video 1). Surgery consisted of disengagement of nervous structures and repair of the neurocutaneous defect, followed on day 12 by a ventriculoperitoneal shunt with a programmable valve. The procedures were well tolerated. At the 14-month follow-up visit he was in range with growth charts (weight, height, and cranic circumference) and gained the physiologic stages of growth. He had no motor impairment but still present were convergent strabismus and mild left C5-C6 radiculopathy, secondary to shoulder dystocia. This is the first case reported in the literature of CM-III treated with the 4K 3D ORBEYE exoscope. Advantages of the exoscope were ergonomic positions for operative staff, possibility for the team to assist in the 4K 3D view, especially in cases with a narrow operative field, with a clear and detailed vision, although a learning curve is required6 to become a valid alternative in pediatric neurosurgery.

Chiari III Malformation on Prenatal and Postnatal Imaging Complicated by Syndrome of Inappropriate Secretion of Anti-diuretic Hormone (SIADH) and Serratia marcescens Meningitis

Among various types of Chiari malformations (CMs), CM III is the most infrequently encountered. In this article, we present a case of CM III with occipital cephalocele appreciated on both prenatal imaging and postnatal follow-up MRI. This case illustrates not only the evolution of this malformation from the in-utero images of fetal MRI to the newborn MRI but also highlights the complications that may accompany this diagnosis such as hydrocephalus and infection. The patient also developed syndrome of inappropriate secretion of anti-diuretic hormone (SIADH). The most current thoughts on the pathophysiology of this entity are also reviewed along with an approach to the differential diagnosis and treatment.