Endoscopic cystoventriculostomy and ventriculocysternostomy using a recently developed 2.0 micron near infrared laser in patients with hydrocephalus

Aims: Preterm infants and other patients with posthaemorrhagic or postinfectious hydrocephalus have a high incidence of ventricular or arachnoic cysts and CSF entrapment. In these cases fenestrations and creating windows within separating membranes to avoid multiple catheters is the purpose of neurosurgical therapy. Although Nd:YAG- and diode-lasers have been already used in neuroendoscopy, surgeons avoid to use high energy lasers in proximity to vital structures depending on their inadequate wavelength. Using a Laser with high absorption coefficient inside watermedia the instrument is applicable inside the ventricles. Methods: Between 2002 and 2006 50 patients between 3 month and 80 years old (mean: 24y) were operated by endoscopy. Most patients suffered from complex hydrocephalus or loculated ventricles, some were treated by third ventriculostomy and aquaeductoplasty. We used a RevolixTM continuous wave-Laser and a 3mm PaediscopeTM or a 6mm NeuroendoscopeTM (Braun Aesculap, Melsungen, Germany). The beam was conducted through a flexible 365 micron bare silica fibre introduced through the endoscope's working channel. The laser power was adjusted to levels between 5 and 10 Watt continuous mode or chopped at frequencies between 5 and 10Hz. Other cases were cystic tumour biopsies or rescue of lost and fixed catheters. Results: The laser created in all applications a smooth and well defined stoma or fenestration without any bleeding. CSF communication was achieved in all cases. There was no mortality or morbidity attributable to the technique. In all ventriculostomies the created stoma was sufficient. One child needed a shunt two weeks after surgery although MRI depicted an open stoma. Conclusion: The authors conclude that the use of the Laser-assisted neuroendoscopy is a safe and gently applicable method.