Communicating Hydrocephalus Associated with Small- to Medium-Sized Vestibular Schwannomas: Clinical Significance of the Tumor Apparent Diffusion Coefficient Map

Hydrocephalus in patients with vestibular schwannoma

BACKGROUND

Hydrocephalus (HC) is common in patients with vestibular schwannoma (VS). This can be managed with a cerebrospinal fluid (CSF) diversion procedure prior to VS resection or with VS resection, keeping CSF diversion in reserve unless required postoperatively. No clear consensus exists as to which approach is superior. This study identifies factors predictive of the development of HC, and analyses outcomes for those managed with primary CSF resection versus tumour resection.

METHODS

Single-centre retrospective cohort study of 204 consecutive adult patients with a unilateral VS from May 2009 to June 2021. Data was collected on patient and tumour demographics, management, and outcome.

RESULTS

204 patients, with a mean age at presentation of 59.5 (21-83), with 50% female, and a mean follow-up of 7.5 years (1.8-13.9) were included. 119 were managed conservatively, 36 with stereotactic radiosurgery only, and 49 with surgery. 30 (15%) patients had radiological HC, of which 23 (77%) were obstructive, and 7 (23%) were communicating. Maximum intracranial tumour diameter and Koos grade were higher in patients with HC. Of the patients with HC the majority (20, 67%) were managed initially with CSF diversion, with 12 patients undergoing subsequent tumour resection, and three patients avoiding primary resection. Nine (30%) were managed with primary surgical resection, of whom three required subsequent CSF diversion. Complication rates and Modified Rankin Scale (MRS) were comparable or lower in the CSF diversion group (8%, MRS ≤2 = 83%), versus the primary resection group (67%, MRS ≤2 = 67%), and the primary surgical resection without HC group (25%, MRS ≤2 = 86%).

CONCLUSIONS

CSF diversion prior to tumour resection is a safe and acceptable strategy compared to primary VS resection, with improved outcomes and reduced surgical complications. Randomized studies and national databases are needed to determine the long-term outcomes of patients treated with CSF diversion versus primary resection.

Obstructive Hydrocephalus Due to Posterior Fossa Tumors in Adults: A Comparative Analysis of 3 Surgical Techniques

BACKGROUND

The main treatments for hydrocephalus due to posterior fossa tumors are tumor resection with or without an external ventricular drain, ventriculoperitoneal shunt (VPS), and endoscopic third ventriculostomy. Although preoperative cerebrospinal fluid diversion by any of these techniques improves clinical outcomes, evidence comparing the efficacy of these techniques is scarce. Therefore, we aimed to retrospectively evaluate each treatment modality.

METHODS

This single-center study analyzed 55 patients. Treatments were classified as successful (hydrocephalus resolution with a single surgical event) or failed and compared with a χ2 test. Kaplan-Meier curves and log-rank tests were employed. A Cox proportional hazard model was used to determine relevant covariates predicting outcomes.

RESULTS

Mean patient age was 36.3 years, 43.4% of patients were men, and 50.9% of patients presented with uncompensated intracranial hypertension. Mean tumor volume was 33.4 cm3, and extent of resection was 90.85%. Tumor resection with or without an external ventricular drain was successful in 58.82% of cases, VPS was successful in 100%, and endoscopic third ventriculostomy was successful in 76.19% (P = 0.014). Mean follow-up time was 15.12 months. Log-rank test found statistically significant differences between survival curves of treatments (P = 0.016) favoring the VPS group. Postoperative surgical site hematoma was a significant covariate in the Cox model (hazard ratio = 17; 95% confidence ratio, 2.301-81.872; P = 0.004).

CONCLUSIONS

This study favored VPS as the most reliable treatment of hydrocephalus due to posterior fossa tumors in adult patient; however, several factors influence clinical outcomes. We proposed an algorithm based on our findings and other authors' findings to facilitate the decision-making process.

Communicating Hydrocephalus Following Treatment of Cerebellopontine Angle Tumors

OBJECTIVE

This study aimed to clarify the risk of communicating hydrocephalus in cerebellopontine angle tumors, focusing on distinct tumor types and treatment modalities, i.e., tumor resection and stereotactic radiosurgery (SRS).

METHODS

This study was a retrospective single-center cohort study. The cumulative incidences of symptomatic communicating hydrocephalus in schwannoma and meningioma patients were evaluated. A multivariate Cox model was used to assess the hazard ratios for the risk factors and odds ratios of distinct treatment subgroups.

RESULTS

A total of 405 cases, including 286 schwannomas and 119 meningiomas, were retrospectively reviewed. The risk of hydrocephalus was significantly higher in schwannomas than that in meningiomas (hazard ratio, 4.70 [95% confidence interval, 1.78-12.4, P = 0.002]). Patients with schwannomas who received SRS without tumor resection showed a significantly higher incidence than meningioma cases: 10.6% versus 1.4% (P = 0.037). We identified specific subgroups that were prone to increase the risk of hydrocephalus when treated with SRS alone. The result showed that patients with vestibular schwannoma of Koos grade III had a greater benefit from tumor resection than from SRS in preventing hydrocephalus (odds ratio, 0.089 [95% confidence interval, 0.011-0.743, P = 0.025]).

CONCLUSIONS

Symptomatic communicating hydrocephalus is more frequent in schwannoma than that in meningiomas. Primary treatment with tumor resection lowers the risk of hydrocephalus in specific subgroups of vestibular schwannoma.

Analysis of Related Factors Affecting Facial Nerve Function after Acoustic Neuroma Surgery

Objective

To investigate the factors affecting facial nerve function after acoustic neuroma surgery and to provide theoretical reference for clinicians to preserve facial nerve function better after surgery.

Methods

A retrospective cohort study was conducted to analyze the correlation between postoperative facial nerve function and surgical approach, age, sex, tumor size and adhesion degree of facial nerve in 152 patients with acoustic neuroma.

Results

In the choice of surgical approach, there was no significant difference in the anatomy of the complete facial nerve in labyrinth path, retrosigmoid sinus path, and middle cranial fossa path. There was no statistically significant difference between the middle cranial fossa path and the retrosigmoid sinus path in facial nerve function preservation 7 days after surgery. The difference between middle cranial fossa path and labyrinthine path was statistically significant (P < 0.01). There were statistically significant differences between labyrinth path and retrosigmoid sinus path (P < 0.05). Logistic multivariate regression analysis showed that the operative approach and the degree of adhesion between tumor and facial nerve were the risk factors affecting functional preservation of facial nerve 7 days after surgery. Age and the degree of adhesion between tumor and facial nerve were the risk factors for functional preservation of facial nerve 1 year after operation.

Conclusion

The facial nerve function injury in patients with acoustic neuroma may be related to the choice of surgical approach, the adhesion degree of tumor and facial nerve, and their age. Clinicians need to comprehensively evaluate the risk factors before surgery, so as to achieve individualized treatment to protect the integrity of postoperative facial nerve function of patients.

Refractory communicating hydrocephalus after radiation for small vestibular schwannoma with asymptomatic ventriculomegaly: A case report

Communicating hydrocephalus is a known tumor-related syndrome associated with vestibular schwannoma, which can occur even in small tumor. Radiation has become a popular primary treatment option for small schwannoma; however, little is known about the efficacy and risk accompanying asymptomatic ventriculomegaly on images. We report a case of a 59-year-old woman who suffer from refractory communicating hydrocephalus after radiation for small vestibular schwannoma with asymptomatic ventriculomegaly. After the surgical removal of the tumor, hydrocephalus was gradually improved due to intermittent lumbar puncture and finally resolved without shunt placement. Surgical removal should be considered as the first option for the treatment, even if the patient is asymptomatic and the images revealed a small vestibular schwannoma with only slight ventricular enlargement.

Characteristics and management of hydrocephalus associated with vestibular schwannomas: a systematic review

Hydrocephalus (HC) can be associated with vestibular schwannoma (VS) at presentation. Although spontaneous resolution of HC after VS removal is reported, first-line treatment is varied including preoperative ventriculoperitoneal (VP) shunt, external ventricular drainage (EVD), or lumbar drainage (LD). We performed a systematic review to clarify optimal management of HC associated with VS at presentation, as well as characteristics of patients with initial and persistent HC after VS removal, and prevalence of HC associated with VS. Fourteen studies were included. Patients were grouped according to the timing of HC treatment. The overall rate of VP shunts was 19.4%. Among patients who received VS removal as first-line treatment, 6.9% underwent permanent shunts. In a subgroup of 132 patients (studies with no-aggregate data), t test analysis for mean tumor size (P = 0.02) and mean CSF protein level (P < 0.001) demonstrated statistically significant differences between patients with resolved HC (3.48 cm and 201 mg/dL) and patients with persistent HC (2.46 cm and 76.8 mg/dL) after VS resection. Transient treatment of HC using EVD or LD further resolved the HC in 87.5% and 82.9% of patients, respectively, before and after VS removal. The overall prevalence of HC associated with VS in a population of 2336 patients was 9.3%. Schwannoma removal as first-line treatment is justified by its low rate of persistent HC requiring VP shunt (roughly 7%). Patients with smaller VS and lower CSF proteins present higher risk of persistent HC after schwannoma removal. Temporary treatment of HC contributes to its resolution, both before and after VS removal.

Frequency and treatment of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients

BACKGROUND

There is paucity of information about the frequency of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients and about the best way it should be managed. The present study was conducted to determine the frequency of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients as well as the value of an endoscopic third ventriculostomy (ETV) prior to posterior fossa tumor surgery with regard to the rate of perioperative complications and persistent hydrocephalus.

METHODS

A single-institution retrospective chart review of all posterior fossa tumor surgeries of our department in a 10-year period (2005 to 2014) has been done.

RESULTS

Fifty-two of 243 adult patients with posterior fossa tumors presented with hydrocephalus at the time of admission prior to tumor surgery. 39/52 received early tumor surgery, 11/52 an ETV prior to tumor surgery and in 2/52 an external ventricular drainage (EVD) was inserted prior to tumor surgery. 3/52 patients required a permanent cerebrospinal fluid (CSF) diverting procedure for persistent hydrocephalus after tumor removal. One hundred ninety-one patients did not demonstrate a hydrocephalus before surgical treatment and four of them developed a post-resection hydrocephalus.

CONCLUSION

The frequency of hydrocephalus prior to posterior fossa tumor surgery in adult patients is 21.4% and therefore much lower than in respective reports of pediatric patients. The risk of persistent hydrocephalus and newly developed hydrocephalus after tumor surgery was very low, too (5.7 and 2.1%, respectively). An ETV is not justified in every adult patient prior to posterior fossa tumor surgery.