An Analysis of Temporal Trend of Incidence of Post-Resection Cerebrospinal Fluid Diversion in Pediatric Posterior Fossa Tumor Patients and the Predictive Factors

Objective: We aim to find the temporal trend of incidence of post-resection cerebrospinal fluid (CSF) diversion (ventriculoperitoneal [VP] shunt/endoscopic third ventriculostomy [ETV]) in pediatric posterior fossa tumor (pPFT) patients with no pre-resection CSF diversion and the possible clinical predictors. Methods: We reviewed 108 operated children (age =16 years) with PFTs, from 2012 to 2020, at a tertiary care center. Patients with preoperative CSF diversion (n = 42), lesions within cerebellopontine cistern (n = 8), and those lost to follow-up (n = 4) were excluded. Life table, Kaplan-Meier curve, univariate and multivariate analyses were used to determine CSF-diversion-free survival and independent predictive factors, with significance defined as P < 0.05. Results: The median (IQR) age was 9 (7) years (M: F: 2.5:1). Mean (+/- SD) duration of follow-up was 32.43 +/- 21.3 months. 38.9% of patients (n = 42) needed post-resection CSF diversion. Of these, 64.3% (n = 27) were done in early (= 30 days), 23.8% (n = 10) in intermediate (>30 days to =6 months), and 11.9% (n = 5) in late (=6 months) postoperative period (P-value < 0.001). Preoperative papilledema (HR: -5.8, 95%CI: 1.7-5.8), periventricular lucency (PVL) (HR: 6.2, 95%CI: 2.3-16.6), and wound complication (HR: 3.8, 95%CI: 1.7-8.3) were found on univariate analysis as significant risk factors for early post-resection CSF diversion. On multivariate analysis, PVL on preoperative imaging (HR: -4.2, 95%CI: 1.2-14.7, P = 0.02) was identified as an independent predictor. Preoperative ventriculomegaly, raised intracranial pressure and intraoperative visualization of CSF egress from the aqueduct were not found to be significant factors. Conclusion: Significantly high incidence of post-resection CSF diversion in pPFTs occurs in early (=30 days) postoperative period, with preoperative papilledema, PVL, and wound complication being its significant predictive factors. Postoperative inflammation, causing edema and adhesion formation can be one of the important factors for post-resection hydrocephalus in pPFTs.