Infection is a serious complication of external ventricular drain (EVD) and various strategies have been adopted to minimize its occurrence. The use of an extended subcutaneous tunnel (50-60 cm) was previously described, but has since received little attention in the literature. The authors reviewed their experience with this technique, with emphasis on the rate of infection and predisposing risk factors. This is a retrospective review of 114 patients who received EVD with extended subcutaneous tunnel ('long EVD'). Fourteen of the 114 patients underwent more than one insertion, and a total of 133 cases of 'long EVD' were included. The mean duration of drainage was 20 days. One-hundred-and-three cases started without pre-existent infection and seven became infected, yielding an overall infection rate of 6.8%. The majority of infections were found within the first 5 days and in the third week of drainage. There was, however, no statistically significant difference in daily infection risks between the first, second and third weeks. Only intraventricular instillation of urokinase was identified as a statistically significant risk factor. Non-infective complications occurred in 17 cases (12.8%). In the present study, the overall infection rate of the 'long EVD' was comparable with that of conventional EVD, as reported by other authorities in the literature. The extended subcutaneous tunnel technique did not affect the daily infection risk on a week-to-week basis. The 'long EVD' does not appear to offer any distinct advantage over the standard tunnelling technique in our unit. However, this is essentially an audit within a single centre, and the findings should be interpreted with caution and with the understanding that individual institutions may have their unique patterns and risks of EVD infection.

Objective: To explore the prognostic significance of metabolic parameters in postoperative peritumoral edema zone (PEZ) of patients with glioblastoma (GBM) based on proton magnetic resonance spectroscopy (MRS).Methods: The postoperative MRS data of 67 patients with GBM from Beijing Tiantan Hospital were retrospectively reviewed. Metabolite ratios including Cho/NAA, Cho/Cr, and NAA/Cr in both postoperative PEZ and contralateral normal brain region were recorded. Log-rank analysis and Cox regression model were used to identify parameters correlated with progression-free survival (PFS) and overall survival (OS).Results: Compared with the contralateral normal brain region, postoperative PEZ showed a lower ratio of NAA/Cr (1.20 ± 0.42 vs. 1.81 ± 0.48, P < 0.001), and higher ratios of Cho/Cr and Cho/NAA (1.36 ± 0.44 vs. 1.02 ± 0.27, P < 0.001 and 1.32 ± 0.59 vs. 0.57 ± 0.14, P < 0.001). Both the ratios of Cho/NAA and NAA/Cr were identified as prognostic factors in univariate analysis (P < 0.05), while only Cho/NAA ≥ 1.31 was further confirmed as an independent risk factor for early recurrence in the Cox regression model (P < 0.01). According to the factors of MGMT promoter unmethylation, without radiotherapy and Cho/NAA ≥ 1.31, a prognostic scoring scale for GBM was established, which could divide patients into low-risk, moderate-risk, and high-risk groups. There was a significant difference of survival rate between the three groups (P < 0.001).Conclusions: Higher Cho/NAA ratio in the postoperative PEZ of GBM predicts earlier recurrence and is associated with poor prognosis. The prognostic scoring scale based on clinical, molecular and metabolic parameters of patients with GBM can help doctors to make more precise prediction of survival time and to adjust therapeutic regimens.

Background: External ventricular drainage (EVD) is common after brain surgery. However, the incidence of EVD-related infection (ERI) is still relatively high and can increase morbidity and mortality.Objective: The objective of this study was to analyze ERI factors in pediatric population post-brain tumor surgery.Methods: From January 2016 to December 2017, 147 patients <18 years old underwent tumor removal at Beijing Tiantan Hospital and had postoperative EVD. We recorded basic demographic data as well as several risk factors. We then analyzed whether these factors were related to ERI.Results: Patients with a preoperative ventriculo-peritoneal (V-P) shunt, those with longer operation time, those who received blood transfusion, those with more frequent cerebrospinal fluid (CSF) sampling, and those with longer indwelling time of EVD had higher risks of infection (p < 0.05). Logistic regression analysis confirmed that a preoperative V-P shunt, operative duration, intraoperative blood transfusion, frequency of CSF sampling, and EVD duration were correlated with postoperative ERI (p < 0.05).Conclusion: EVD should be removed as soon as possible and any unnecessary procedures should be avoided to reduce the infection rate. However, prophylactic treatment should be given in case patients do not meet the indication for EVD removal.