Chapter 15. Neurointerventional Surgery
A 10-day-old neonate with severe hydrocephalus is being evaluated for refractory congestive heart failure. As part of the evaluation, a cranial ultrasound is performed and demonstrates an abnormal vascular structure. Brain magnetic resonance imaging (MRI)/magnetic resonance venography (MRV) and computed tomography (CT) scan are obtained and shown below. Which of the following is the best treatment option?
A and B. Magnetic resonance angiography of brain. C. T2 fluid-attenuated inversion recovery coronal magnetic resonance imaging of brain. D. Noncontrast coronal compute tomography scan.
A. Start anticoagulation using low-molecular-weight heparin
B. Continued aggressive medical management with surgical intervention planned at 5 to 6 months of age
C. Urgent referral for endovascular embolization
D. Placement of a ventriculoperitoneal shunt
E. Microsurgical removal of the abnormality
C. This patient has a vein of Galen malformation (VGM). VGM is a rare congenital vascular malformation that results from maldevelopment of the intracranial embryonic midline venous system at the level of the median prosencephalic vein of Markowski, which is considered as the embryonic precursor of the vein of Galen. VGMs are postulated to arise during the fetal period; they consist of a cerebral arteriovenous malformation draining into the vein of Galen. The age of presentation varies and can be immediately after birth (“neonatal period”; 44% of cases), in infancy (41%), or in the early childhood and adult period (12%). Clinically, patients can have different presentations, including high cardiac output failure secondary to venous shifting phenomena, hydrocephalus (communicating and no-communicating), and cerebral ischemia due to steal phenomena and intracranial hemorrhage.
Ideally, if the patient’s clinical condition is stable and the patient is not in heart failure or does not have signs of cerebral ischemia, treatment should be deferred until 5 to 6 months of age to minimize the risk of affecting brain maturation. Untreated, the mortality rate reaches 100%. Treatment options include surgical, medical, endovascular, and combined. The timing of treatment has always been controversial; the 12-point Bicêtre scoring system is one method used to guide patient selection and timing of intervention in the neonatal period.
The main goal of medical treatment is to decrease the flow through VGM and hemodynamically stabilize the patient until definite treatment can be done safely.
Despite advances in microneurosurgical techniques, complete removal of the lesion in newborns is seldom accomplished or advised because of the hemodynamic instability, location of the lesion, poor myelination of the brain parenchyma (in younger patients), and cerebral venous hypertension. As a result, currently, surgical treatment is reserved for the evacuation of intracranial hematomas, management of hydrocephalus, or in cases of embolization failure.