Factors influencing shunt malfunction in patients with tuberculous meningitis

Abstract

Background Hydrocephalus secondary to tuberculous meningitis (TBM) is a challenging condition to treat. Though ventriculo-peritoneal (VP) shunt is an accepted modality of treatment for hydrocephalus in TBM, there is a high rate of complications associated with the same. Objective The study was planned to evaluate various factors associated with shunt malfunction in patients undergoing VP shunt surgery for hydrocephalus due to TBM. Materials and Methods A retrospective review of all the patients undergoing VP shunt and shunt revision for TBM between 2004 and 2008 was performed. 449 VP shunt surgeries were performed in 432 patients for hydrocephalus due to TBM. Among these 70 shunt revisions were performed in 53 patients. Results Shunt malfunction rate in our series was 16.2%. High cerebrospinal fluid (CSF) protein concentration (>200 mg/dL) was associated with 5 times increased incidence of shunt malfunction. Patients with hyponatremia (Na+ <130 mEq/dL) prior to surgery had a 3 times increased incidence of shunt malfunction (P < 0.05). Other factors such as duration of symptoms, presence of neurological deficits, Evan’s index, third ventricular diameter, thickness of exudates, presence of infarcts, anemia, CSF cellularity and CSF glucose concentration were not associated with increased incidence of shunt malfunction. Analysis showed that shunt viability was longest in patients with normal serum sodium levels and CSF protein concentration less than 200 mg/dL and shortest in patients with low serum sodium and CSF protein concentration more than 200 mg/dL. Conclusions Patients with pre-operative hyponatremia and high CSF protein concentration have a higher incidence of shunt malfunction and need to be followed-up closely.

Keywords

• hydrocephalus
• hyponatremia
• shunt malfunction
• tuberculous meningitis
• ventriculo-peritoneal shunt