Archives of Pediatric Neurosurgery (Jan 2021)
Tips and Tricks in Difficult ETV
Abstract
The neuroendoscopy is supported by three pivotal pillars: training, planning, and prudence. The training consists of attending practical courses with synthetic head models for immersion in the intricate ventricular anatomy and practice in handling the neuroendoscope. The planning begins with the choice of the entry point, usually performed at the Kocher's point, and measurement of this to the ventricle. Neuroendoscopy in intraventricular hemorrhage or ventriculitis is always challenging due to low visibility, thus, copious irrigation with a heated solution at 37°C, like plasma type, is mandatory, often reaching 6L of solution. Narrow spaces between the clivus and basilar artery can be very dangerous, therefore we prefer a "Sputnik" fórceps rather than blunt instruments to open the floor of the III ventricle and subsequently widen it with Fogarty n°3. Sometimes it is necessary to mechanically remove the larger clots that do not come off the ventricle walls only with irrigation; in these cases, we aspirate them through the neuroendoscope until we see the structures that allow us to perform ETV and guarantee its patency. Navigating inside the ventricle when the complex anatomy is distorted, such as cases of myelomeningoceles with large interthalamic masses, can be very difficult; for these cases, we use the optics inversion technique to access different locations with the same field of view. The innovation in neuroendoscope models allowed us to associate techniques, such as the concomitant use of an ultrasonic aspirator to remove intraventricular lesions. Another field of great development was fetal surgery for hydrocephalus; initially with cephalocenteses passing through the ventriculo-aminiotic shunt until the fetal ETV. For complex cases of the second look of ETV, we can still associate techniques such as aqueductoplasty and implantation of stents in the third ventricular floor and cerebral aqueduct to keep them patent. Last but not least, we have the pillar of prudence. Any neuroendoscopy, regardless of the surgeon's experience or the apparent simplicity of the case, must be done with the utmost caution, avoiding minimal bleeding, avoiding touching structures that are not vital to the procedure, and be objective.
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