Since 1995, in several hospitals, any patients more than 6 months of age with triventricular hydrocephalus were considered for ETV. The third ventricle have to be greater than 4 mm of width. Cotraindication is considered the communicating hydrocephalus
The most used preoperative study is Magnetic Resonance Imaging (MRI). The endoscope is introduced into the lateral ventricle through a burr hole placed just over or near the coronal suture.
Then the nedoscope is passed into the third ventricle via foramen of Monro. The shunt is performed by perforating the floor of third ventricle between the infundibular recess of pituitary stalk and the anterior border of mamillary bodies.
The basilar artery is just behind the perforated membrane and we use great care during the surgical procedure. The instrument to cause the fenestration are various. We used forceps, bipolar cautery or unipolar cautery.
The fenestration in the membrane is then enlarged by a balloon catheter with a width of about 5 mm. Sometime a second unnoticed membrane is present so that it is possible an early failure of the operation. Complications: hypothalamic injury; transient third and sixth nerve palsies; subarachnoid hemorrhage; subdural hemorrhage at the entry site; infection (factor risk especially for pre-shunted patient); cardiac arrest; obstruction by gliotic tissue (delayed failure); increased concentration of protein and fibrinogen causing early obstruction of the stoma. Mortality rates of 1 to 5% have been observed in medical literature.
The most used preoperative study is Magnetic Resonance Imaging (MRI). The endoscope is introduced into the lateral ventricle through a burr hole placed just over or near the coronal suture.
Then the nedoscope is passed into the third ventricle via foramen of Monro. The shunt is performed by perforating the floor of third ventricle between the infundibular recess of pituitary stalk and the anterior border of mamillary bodies.
The basilar artery is just behind the perforated membrane and we use great care during the surgical procedure. The instrument to cause the fenestration are various. We used forceps, bipolar cautery or unipolar cautery.
The fenestration in the membrane is then enlarged by a balloon catheter with a width of about 5 mm. Sometime a second unnoticed membrane is present so that it is possible an early failure of the operation. Complications: hypothalamic injury; transient third and sixth nerve palsies; subarachnoid hemorrhage; subdural hemorrhage at the entry site; infection (factor risk especially for pre-shunted patient); cardiac arrest; obstruction by gliotic tissue (delayed failure); increased concentration of protein and fibrinogen causing early obstruction of the stoma. Mortality rates of 1 to 5% have been observed in medical literature.
References
- Handbook of Neurosurgery - fifth edition - Mark S. Greenberg - ed. Thieme.
- Kandrian D, van Gelder J, Florida D, Jones R, Vonau M, Teo C, Stening W, Kwok B. Long-term reliability of endoscopic third ventriculostomy. Neurosurgery 56:1271-1278, 2005.
- Mobbs JR, Vonau M, Davies MA, .Death after late failure of endoscopic third ventriculostomy: a potential solution. Neurosurgery 53:384-386, 2003.
