OBJECTIVE: The occurrence and predictors of symptomatic subdural hygroma (SSH) subsequent to the fenestration of pediatric intracranial arachnoid cysts (IACs) are unclear. In this study, the authors aimed to investigate the likelihood of an SSH following IAC fenestration and the impact on operative efficacy with the ultimate goal of constructing a nomogram.
METHODS: The medical records of 1782 consecutive patients who underwent surgical treatment at the Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were reviewed. Among these patients, a training cohort (n = 1214) underwent surgery during an earlier period and was used for the development of a nomogram. The remaining patients formed the validation cohort (n = 568) and were used to confirm the performance of the developed model. The development of the nomogram involved the use of potential predictors, while internal validation was conducted using a bootstrap-resampling approach.
RESULTS: SSH was detected in 13.2% (160 of 1214) of patients in the training cohort and in 11.1% (63 of 568) of patients in the validation cohort. Through multivariate analysis, several factors including Galassi type, IAC distance to the basal cisterns, temporal bulge, midline shift, IAC shape in the coronal view, area of the stoma, and artery location near the stoma were identified as independent predictors of SSH. These 7 predictors were used to construct a nomogram, which exhibited a concordance statistic (C-statistic) of 0.826 and demonstrated good calibration. Following internal validation, the nomogram maintained good calibration and discrimination with a C-statistic of 0.799 (95% CI 0.665-0.841). Patients who had nomogram scores < 30 or ≥ 30 were considered to be at low and high risk of SSH occurrence, respectively.
CONCLUSIONS: The predictive model and derived nomogram achieved satisfactory preoperative prediction of SSH. Using this nomogram, the risk for an individual patient can be estimated, and the appropriate surgery can be performed in high-risk patients.

Chronic subdural hematoma (CSDH) and symptomatic subdural hygroma are common diseases that require neurosurgical management. Burr hole trephination is the most popular surgical treatment for CSDH and subdural hygroma because of a low recurrence rate and low morbidity compared with craniotomy with membranectomy, and twist-drill craniotomy. Many reports suggest that placing a catheter in the subdural space for drainage can further reduce the rate of recurrence; however, complications associated with this type of drainage include acute subdural hematoma, cortical injury, and infection. Remote hemorrhage due to overdrainage of cerebrospinal fluid (CSF) is another possible complication of burr hole trephination with catheter drainage that has rarely been reported. Here, we present 2 cases of remote hemorrhages following burr hole trephination with catheter drainage for the treatment of CSDH and symptomatic subdural hygroma. One patient developed intracerebral hemorrhage and subarachnoid hemorrhage in the contralateral hemisphere, while another patient developed remote hemorrhage 3 days after the procedure due to the sudden drainage of a large amount of subdural fluid over a 24-hour period. These findings suggest that catheter drainage should be carefully monitored to avoid overdrainage of CSF after burr hole trephination.