Analysis of Evolution of Hydrocephalus in Posterior Fossa Tumors and Validation Study of the Modified Canadian Preoperative Prediction Rule for Hydrocephalus in Children and Frankfurt Grading System for Prediction of Cerebrospinal Fluid Diversion in Adults with Posterior Fossa Tumors.

OBJECTIVE: We sought to analyze the evolution of hydrocephalus and enumerate its predictive factors in posterior fossa tumors in children and adults. We also validated the modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) and Frankfurt grading systems as tools to predict cerebrospinal fluid (CSF) diversion in children and adults, respectively. METHODS: A retrospective review of patients with posterior fossa tumors operated between 2012 and 2019 was performed. Clinical, radiologic, and operative data were obtained. Validation was performed for both scores via receiver operating characteristic (ROC) curves and evaluation of the area under the curve (AUC). RESULTS: We included 116 children and 343 adults in the study. Of the adults, 141 patients had intraaxial tumors and 172 had extraaxial tumors. The insertion of external ventricular drain (EVD), its duration, papilledema was noted to have significant influence on the need for permanent CSF diversion (P < 0.05) in children. The ROC for mCPPRH score was 0.659 (0.501-0.816), Age- 0.496 (0.334-0.658) and Evans index- 0.788 (0.654-0.922). In adults- Intraaxial tumours Age, Frankfurt score, duration of EVD, Diagnosis, Extent of resection and periventricular capping significant predictors and ROC age AUC 0.300 (0.193-0.407), Evans index 0.939 (0.888-0.990), and Frankfurt score 0.908 (0.853-0.964) (P < 0.05), whereas in extraaxial tumors Frankfurt grading, sex, duration of EVD, presence of perilesional edema and extent of resection (P < 0.05) ROC age AUC 0.439 (0.344-0.534), Evans index 0.941 (0.906-0.977), and Frankfurt score 0.847 (0.782-0.912). CONCLUSIONS: This is the first external validation study for the 2 predictive systems in use. mCPPRH demonstrated poor predictive accuracy, and Frankfurt grading system demonstrated good accuracy. EVD insertion and its duration was significantly predictive of the need for permanent CSF diversion.

Endoscopic Transpterygoid Corridor for Petroclival Tumors: Case Series and Technical Nuances.

Background: The petroclival area is a technically challenging region to operate owing to the proximity of the internal carotid artery (ICA) and the need to obtain gross total excision of tumors in this area as they are often resistant to radiotherapy. Objective: We present our experience with the endonasal endoscopic transpterygoid approach in managing tumors of the petroclival region and discuss various operative nuances for safer resection. Materials and Methods: A retrospective study of all consecutive cases of lesions occupying the petroclival region that were operated via endonasal endoscopic transpterygoid approach at our center between January 2016 and December 2021 was performed. Results: The study included 14 cases of lesions occupying the petroclival region. Gross total resection by intraoperative observation was achieved in 10 patients, near total decompression was performed in two patients, and the remaining two patients underwent marsupialization of lesion. Postoperatively, one patient had right Lower motor neuron (LMN) facial nerve palsy and one patient required surgery for Cerebrospinal fluid (CSF) rhinorrhea on postoperative day 8. The mean duration of follow-up was 13.8 ± 16.6 months (range: 2-59 months). Four of six patients with visual symptoms on presentation reported improvement in vision, and the other two patients had a stable vision on follow-up. Two patients received radiotherapy postsurgery. No mortality was noted. Conclusion: The extended endonasal endoscopic transpterygoid approach can be safely and efficiently used for petroclival lesions. Very sound knowledge of anatomical relationship, use of intraoperative image guidance to avoid injury to ICA, and multilayer reconstruction with a vascularized nasoseptal flap are required to optimize the clinical outcome.