Can We Predict Early Endoscopic Third Ventriculostomy Failure? The Role of Ultra-Early Postoperative Magnetic Resonance Imaging in Predicting Early Endoscopic Third Ventriculostomy Failure

BACKGROUND: The success of endoscopic third ventriculostomy (ETV) depends on multiple preoperative and intraoperative factors. The multifactorial influence adds an element of unpredictability to the outcome of the most well-planned procedure. Clinical symptoms and signs may not reflect the status of the ETV stoma postprocedure and the morbidity associated with ETV failure could be catastrophic. In this study, the authors look at the role of early magnetic resonance imaging (MRI) to predict failure to avoid morbidity secondary to malfunction and propose a modified success criterion to guide treatment plan post-ETV failure. Our aim is to prospectively and retrospectively study the use of early postoperative MRI in predicting potential early ETV failure. METHODS: Patients who underwent ETV at Amrita Institute of Medical Sciences from March 2011 to August 2017. The study was a retrospective and prospective observational blinded study. Inclusion criteria included patients with any form of obstructive hydrocephalus who underwent ETV and had undergone an early postoperative MRI in the first 48 hours—or latest by discharge—with a follow-up of at least 3 months. The patient details and the presence of the flow void in the immediate postoperative MRI were documented. Follow-up was for at least 3 months to identify early failures. RESULTS: A total of 67 ETVs were performed in 65 patients. At 3 months follow-up, of the 59 ETVs with flow void on MRI, 53 were successful, whereas 6 failed. Of the 8 without flow void, 4 were successful. The overall sensitivity was 93.0, whereas specificity was 40.0. With increasing age, the negative predictive value improved from 25% in age <1 year to 100% in age >5 years, with an accuracy reaching 96% to predict failure of ETV. CONCLUSIONS: An early postoperative MRI is very sensitive to failure of ETV, but not highly specific. The negative predictive value and accuracy of MRI improve significantly with increasing age and in non-hemorrhagic non-infective obstructive etiology.