Subdural fluid accumulation caused by ventriculoperitoneal shunt underdrainage: A rare and paradoxical complication

Background: Subdural fluid collection in patients with internal cerebrospinal fluid (CSF) shunts has generally been linked to overdrainage and more rarely to pus accumulation. The authors present a previously unrecognized condition leading to extra-axial CSF accumulation: shunt underdrainage. Treatment of coexisting subdural fluid collection and hydrocephalus, disorders that have previously only been reported concurrently following head trauma or subarachnoid hemorrhage, is controversial. In addition, we intend to provide insight into the physiopathology of abnormal CSF accumulation within both the subdural space and ventricles simultaneously. Case Description: A 42-year-old female with a history of hypothalamic glioma and obstructive hydrocephalus during childhood presented with headache, vomiting, and gait disturbance. Following the insertion of her first ventriculoperitoneal shunt (VPS) by the age of 8, she underwent several surgeries due to shunt failure, all of them associating ventriculomegaly. Ventricles remained notably enlarged following insertion of her most recent VPS, and the computed tomography scan performed 2 months later at her admission showed a large subdural collection. Afterward, a malpositioned distal catheter causing shunt blockage was confirmed. Both, the subdural accumulation and hydrocephalus, were resolved following adequate placement of the peritoneal catheter. Conclusion: This case demonstrates that subdural fluid accumulations may occur following VPS underdrainage with hydrocephalus. Development of such extra-axial collection was probably caused by pressure related to CSF spillage from the ventricles into the subdural space. Our case also supports that a mass-effect subdural accumulation with hydrocephalus can be satisfactorily treated with adequate VPS alone, without directly treating the subdural collection.

Cranioplasty following ventriculoperitoneal shunting: lessons learned

Objective Cranioplasty (CP) is considered as a straightforward and technically unchallenging operation; however, complication rates are high reaching up to 56%. Presence of a ventriculoperitoneal shunt (VPS) and timing of CP are reported risk factors for complications. Pressure gradients and scarring at the site of the cranial defect seem to be critical in this context. The authors present their experiences and lessons learned. Methods A consecutive series of all patients who underwent CP at the authors’ institution between 2002 and 2017 were included in this retrospective analysis. Complications were defined as all events that required reoperation. Logistic regression analysis and chi-squared test were conducted to evaluate the complication rates according to suspected risk factors. Results A total of 302 patients underwent cranioplasty between 2002 and 2017. The overall complication rate was 17.5%. Complications included epi-/subdural fluid collection (7.3%) including hemorrhage (4.6%) and hygroma (2.6%), bone graft resorption (5.3%), bone graft infection (2.0%), and hydrocephalus (5.7%). Overall, 57 patients (18.9%) had undergone shunt implantation prior to CP. The incidence of epi-/subdural fluid collection was 19.3% in patients with VPS and 4.5% in patients without VPS, OR 5.1 (95% CI 2.1–12.4). Incidence of hygroma was higher in patients who underwent early CP. Patients with temporary shunt ligation for CP did not suffer from complications. Conclusion CP in patients with a VPS remains a high-risk procedure. Any effort to understand the pressure dynamics and to reduce factors that may trigger the formation of a large epidural space must be undertaken.

Subdural fluid collection and hydrocephalus following cervical schwannoma resection: hydrocephalus resolution after spinal pseudomeningocele repair: case report

The authors report the case of a 31-year-old man who developed neck pain and headache 2 months after the uncomplicated resection of a cervical schwannoma. MR imaging revealed infratentorial subdural fluid collections and obstructive hydrocephalus associated with cervical pseudomeningocele. The clinical symptoms, subdural fluid collections, and ventricular dilation resolved after surgical correction of the pseudomeningocele. This report emphasizes that hydrocephalus may be related to disorders of cerebrospinal fluid flow dynamics induced by cervical pseudomeningocele. In these rare cases, both the hydrocephalus and the symptoms are resolved by the simple correction of the pseudomeningocele.