Endoscopic third ventriculostomy for tuberculous meningitis hydrocephalus treatment
The management for tuberculous meningitis hydrocephalus has undergone a change since the advent of neuroendoscopy. Ventriculoperitoneal shunt is no longer the treatment of choice in all cases. These patients should undergo an endoscopic procedure, which has shown promising results and more importantly saves these patients of the shunt related complications 1).
The shunts tend to get blocked with debris. Having found ETV as a successful modality of treatment in obstructive hydrocephalus of other etiology, neurosurgeons have attempted it in hydrocephalus of tubercular origin. Though various authors have had a success rate of 65-68%, failure has been quite high in acute cases due to thickening of the floor of third ventricle and distorted anatomy. The success rate is higher in chronic and burnt out cases.
Conclusion: Tubercular meningitic hydrocephalus is difficult to treat endoscopically as compared with other forms of meningitic hydrocephalus and requires adequate expertise and experience, especially in acute cases. Therefore, one would be justified in avoiding the use of ETV in acute cases and wait till patient presents with a failed shunt. Use of ETV in subacute and chronic cases seems to be justified as the first line of treatment 2).
Sharma et al.recommend that shunt treatment should not be performed in HIV-positive patients in poor Palur grade with hydrocephalus. A trial of external ventricular drainage should be undertaken in such patients, and shunt treatment should be performed only if there is any improvement. However, HIV-positive patients in good Palur grades should undergo ventriculoperitoneal shunt placement, as these patients have better outcomes than previously reported 3).
Case series
study is aimed to evaluate the role of ETV in TBM hydrocephalus.
Materials and methods: This is a prospective study of 59 patients with TBM and obstructive hydrocephalus. The diagnosis was confirmed by a computed tomography scan and/or magnetic resonance imaging scan preoperatively. The procedure was performed using the standard technique or water jet dissection.
Results: Three (5.1%) patients had blocked stoma, 31 (53%) had associated malnutrition, and 13 (22%) had complex hydrocephalus. Clinical improvement was seen in 34 (58%) after ETV and in 47 (80%) patients after ETV with lumber peritoneal shunt. Thirteen patients with patent stoma and complex hydrocephalus did not improve after ETV alone; an additional lumber peritoneal shunt was required. Clinical outcome was significantly better in good grade. Early recovery was observed in 81%. Results of ETV were better in patients without cisternal exudates, good nutritional status, thin and identifiable floor of third ventricle compared to cases with cisternal exudates, malnourished, thick and unidentifiable floor respectively, although the difference was statistically insignificant. There was no operative death. Three patients with normal ICP did not show any improvement. The radiological recovery after 3 weeks of surgery was 52%; follow-up ranged between 7 and 54 months. Six patients developed Cerebrospinal fluid fistula.
Conclusion: Endoscopic third ventriculostomy was safe and effective in TBM hydrocephalus. Complex hydrocephalus and associated cerebral infarcts were the major causes of failure to improve. Good results were observed in better grades 4).
Twenty-six patients with TBM hydrocephalus treated with ETV were evaluated clinically and with cine MR imaging postoperatively. The duration of follow-up ranged from 1 to 15 months. The authors evaluated flow void changes in the floor of the third ventricle and analyzed parameters from the preoperative data, which they then used as a basis for comparison between endoscopically successful and endoscopically unsuccessful cases.
Results: The overall success rate of ETV in TBM hydrocephalus was 73.1% in this case series. Cine MR imaging showed a sensitivity of 94.73% and specificity of 71.42% for the functional assessment of third ventriculostomy in these patients, with the efficacy being maintained during follow-up. The outcome of ETV showed a statistically significant correlation with the stage of illness and presence of intraoperative cisternal exudates. Although duration of symptoms and duration of preoperative antituberculous therapy (ATT) appeared to influence the outcome, their correlation with outcome was not statistically significant.
Conclusions: Endoscopic third ventriculostomy should be considered as the first surgical option for CSF diversion (that is, before shunt surgery) in patients with TBM hydrocephalus. Cine MR imaging is a highly effective noninvasive tool for the postoperative functional assessment of stomata. Patients who presented with a history of longer duration and those who were administered preoperative ATT for a longer period had a better outcome of endoscopic treatment. Outcome was poorer in patients who presented with higher stages of illness and in those in whom cisternal exudates were observed intraoperatively 5).
Post-tubercular meningitic hydrocephalus (TBMH) and post-traumatic hydrocephalus (PTH) is often considered a contraindication for endoscopic third ventriculostomy (ETV), as it is mostly of communicating type in these cases. The aim of the present study was to define the role of ETV in patients with communicating hydrocephalus. Ten consecutive patients of TBMH, PTH and postneurocysticercus (NCC) hydrocephalus were formed the study group. Diagnosis of communicating hydrocephalus was made using magnetic resonance ventriculography (MRV). If contrast was seen coming out from the ventricular system into the basal cisterns, it was considered as communicating hydrocephalus. Patients with clinical and imaging evidence of raised intracranial pressure and failed medical treatment were taken up for ETV. All patients were studied by preoperative and postoperative MRV. Success of the procedure was assessed by the improvement in clinical and imaging parameters on postprocedure follow-up in all these cases. Technically successful ETV was performed in all 10 patients. Overall success rate of ETV in communicating hydrocephalus was 70% (n = 7). The shunt surgery was performed in the remaining three patients with ETV failure. One patient developed complication following postoperative MRV and was managed conservatively. We conclude that ETV is effective in post-TBM, post-traumatic communicating and post-NCC communicating hydrocephalus and should be considered as initial surgical option for Cerebrospinal fluid shunt in these patients. MRV is a relatively safe technique to ascertain the patency of subarachnoid space as well as ETV stoma 6).
Case reports
We report our preliminary experience with two cases of tuberculous meningitis (TBM) in which endoscopic third ventriculostomy (ETV) was performed to treat non-communicating hydrocephalus. For many years, the insertion of ventriculoperitoneal shunts has been the standard treatment for hydrocephalus in patients with TBM, although the indications for and timing of surgery are not uniformly accepted. Shunt insertion is associated with a high incidence of complications, particularly with long-term follow-up. An alternative treatment for hydrocephalus in this group of patients would clearly be of great benefit. The indications for ETV have increased in the last decade, and there are reports of some effectiveness of the procedure in patients with hydrocephalus due to bacterial meningitis. To our knowledge, ETV has not been described in the management of TBM.
Methods: We report the early results of our preliminary experience with ETV in two patients who presented with neurological compromise due to hydrocephalus and raised intracranial pressure. The clinical context and pre-operative investigation of these patients are presented. The emphasis is placed on the distinction between communicating and non-communicating pathologies as a guide to management options. We detail our surgical findings and the peculiar endoscopic challenges that the condition presented to us. Follow-up in these patients included clinical and investigational data suggesting early effectiveness of the procedure in converting non-communicating hydrocephalus into a communicating one, which can then be treated medically.
Discussion: Endoscopic third ventriculostomy is presented as a new application of a procedure accepted for other indications in the treatment of non-communicating hydrocephalus. There are particular aspects of the use of this procedure related to the unique pathology of TBM that are significantly different. We explain our rationale for endoscopy in these patients, and suggest a protocol in which endoscopy may play a role in the management of patients with raised intracranial pressure due to tuberculous hydrocephalus 7).