Vitaly Siomin

Increasing chronic subdural hematoma after endoscopic III ventriculostomy

Abstract Object: Endoscopic III ventriculostomy (ETV) is an effective and a rather safe treatment for noncommunicating hydrocephalus secondary to aqueductal stenosis and other obstructive pathologies. Though not devoid of risk, ETV is increasingly replacing shunt operations, and it prevents related complications, including overdrainage. Methods: We report a rare case of a large chronic subdural hematoma (ChSDH) after ETV in a patient with aqueductal stenosis. Three weeks after he was shunted elsewhere, he presented to us with clinical symptoms of intracranial hypotension and overdrainage. ETV was performed and the shunt removed uneventfully. On routine postoperative MRI a few weeks later, a large ChSDH was noted, the patient being totally asymptomatic. Since the ChSDH grew significantly, causing a mass effect on the follow-up MRI, it was finally drained. Large and increasing ChSDHs have previously been reported secondary to overdrainage after shunt placement, but not after ETV. Conclusions: We conclude that though rare, a ChSDH may evolve even after ETV, if there is a substantial decrease in previously elevated intracranial pressure.

Endoscopic third ventriculostomy in tuberculous meningitis.

Figaji et al. [1] reported their experience with the successful application of endoscopic third ventriculostomy (ETV) in two patients with tuberculous meningitis. The authors should be congratulated for providing a thorough description of the surgical findings and for pointing out the conceptual and technical challenges during decision-making and surgery. We recently reported the results of an international multi-center study of the use of ETV in 101 patients with a history of previous hemorrhage and/or cerebrospinal fluid (CSF) infection [2]. The success rate in 42 patients with a previous history of infection was 64.3%. Notably, neither the type of pathogen nor the severity of the previous infection affected the outcome. We agree with Figaji et al. that ETV should be considered a valid option in a group of patients traditionally considered to be unsuitable for endoscopy. The question is, then, what selection criteria should be employed to achieve maximum success rates and avoid offering an improper procedure to those who may benefit more from a shunt upfront. Figaji et al.’s paper is yet another piece of evidence in support of the high efficacy of endoscopy in the management of tri-ventricular obstructive hydrocephalus regardless of the nature of its cause (e.g., congenital, infectious, or posthemorrhage). Therefore, the ventricular structure and anatomy are currently the best predictors we have for the success of endoscopy. With regard to intraoperative technical difficulties, our overall impression in our group of patients who had a previous infection was that ETV was not significantly more difficult than in other patients. Tuberculous meningitis may be associated with a higher degree of scar and adhesion formation than the bacterial meningitis that caused hydrocephalus in the majority of our patients. Nonetheless, Figaji et al. beautifully illustrated that intra-operative challenges do not make endoscopy impossible. Evaluating a more accurate incidence of complications in this group will require more experience. Till then it would be wise to consider ETV in postinfectious patients, especially post-TB patients, to be an advanced procedure that should be done by experienced endoscopists.

The retrograde ventriculo-sinus shunt

opportunity of commenting on El-Shafei and El-Shafeis article introducing an original concept of ventriculo-sinus shunting. The authors present a large series of 56 patients who have already undergone retrograde ventriculo-sinus shunt placement for hydrocephalus. The underlying principle is that the excessive fluid is drained via a valveless catheter from the ventricle into the superior sagittal sinus against the direction of blood flow. The authors provide a very thoughtful explanation of how the impact pressure of the bloodstream in the venous sinus maintains the unidirectional CSF flow and prevents thrombosis in the catheter. In addition, it seems that siphoning of the fluid can be prevented by the natural collapse of the internal jugular vein in the upright position. As the proposed solution is substantially more “physiological” than the conventional extracranial diversion procedures, the pace and the nature of improvement are similar to those seen in patients who undergo endoscopic third ventriculostomy. The ventricular size does not decrease in most patients, which means that overdrainage is less of a problem. The overall mechanical shunt survival of 89% over an 8-year followup appears superior to the survival periods recorded for most commonly used ventriculo-peritoneal shunts. Overall, we find Drs. El-Shafei highly deserving of credit for establishing this innovative and promising method of treating hydrocephalus. We believe that further studies on efficacy and safety of the retrograde ventriculo-sinus shunt will provide specific indications and that accurate long-term follow-up will also answer the question as to whether its use should be considered the treatment of choice in selected patients with hydrocephalus.

Repeat Third Ventriculostomy

The methods of treating hydrocephalus underwent a dramatic evolution in the last few decades. The initial enthusiasm of the neurosurgical community after years of using shunts as the only treatment of all kinds of hydrocephalus faded despite the fact that dozens of studies have been conducted, and hundreds of significant and seemingly panacean solutions were proposed to improve shunt technology. The reality remains that the overall survival of a shunt and the complication rate have changed only slightly in the last 10–20 years. It seems natural that the alternatives to placement of hardware have been long looked for, and the advent of modern neuroendoscopy in the mid-1980s opened a new page in the history of the war against hydrocephalus, which eventually turned into a war against shunts as well. Endoscopic third ventriculostomies (ETV) have instantly become very popular. ETV is a relatively simple technique, establishes a “natural” pathway for CSF flow, and may help to avoid placement of and reliance upon hardware. ETV is generally considered a safe and effective alternative for patients with triventricular hydrocephalus.

Treatment of Hydrocephalus in Suprasellar Lesions

Hydrocephalus may become a major complicating factor in patients with suprasellar tumors. The differential diagnosis of suprasellar tumors that may potentially cause hydrocephalus is replete with various pathologies. Some tumors are more frequently associated with hydrocephalus (e.g., craniopharyngioma, optic pathway glioma), while others only occasionally cause it (e.g., germ cell tumor, pituitary adenoma, epidermoid cyst, and metastases). As hydrocephalus due to suprasellar tumors is primarily a pediatric neurosurgical problem, this chapter will be dedicated mostly to the management of hydrocephalus in pediatric patients with craniopharyngiomas and optic pathways gliomas (OPG).