Vestibular Schwannoma: Clinical Staging to Estimate Probability of Severe Postoperative Complications
Over the past 40 years, the incidence of vestibular schwannoma (VS) has been increasing. This change is likely explained by increased access to health care and advances in diagnostic technology.
Once discovered, these tumors require careful decision-making about treatment options given the slow rate of tumor growth and morbidity associated with treatment. The decision to pursue surgical management instead of radiotherapy or active surveillance is multifactorial and largely depends on features including age, comorbidity, initial tumor size, rate of growth, hearing status, and patient preference.
The mortality rate in patients surgically managed is very low and affords the opportunity to shift focus to other relevant clinical outcomes, such as recurrence free survival, growth-free survival, surgical complications, facial nerve functioning, hearing preservation, and quality of life.
Patient symptom presentation is a fundamental characteristic of the patient with VS and likely relates to the pathophysiologic characteristics of the tumor. Symptoms at presentation include cardinal symptoms, such as hearing loss, vestibular dysfunction, facial numbness, tinnitus, and headaches. Despite their clinical relevance, symptoms at presentation have not been thoroughly investigated in the context of clinical outcomes.
Symptoms may cause patients to seek medical attention and may provide information regarding the biologic characteristics of the tumor and prognosticate various important outcomes, such as postoperative complications. Complication rates may vary based on surgeon experience; however, surgical approach, surgical volume, and patient features at presentation may also play a role. Capturing symptom information creates an opportunity to better describe the clinical symptom phenotype of VS and apply these phenotypes to prognostic models of clinical outcomes. Harrison J. Smith and team carried out a study to describe symptoms of VS at presentation and incorporate them into a prediction model for severe surgical complications.
A retrospective cohort of patients at a single-center tertiary referral center from January 1, 1998, to October 13, 2020, was studied. Patients diagnosed with sporadic vestibular schwannoma surgically treated at Washington University in St Louis, Missouri, were included. Severe surgical complications within 30 days of surgery as determined by the Clavien-Dindo classification system. Patients experiencing a complication of grade 3 or above were determined to have a severe complication.
- Of 185 patients evaluated, 40 (22%) had severe postoperative complications.
- Twenty of the 40 patients (50%) were women; mean (SD) age was 46 (13) years.
- Patients with severe complications were more likely to have large tumors (>2.5 cm in largest diameter), vestibular symptoms, and recent hearing loss at presentation.
- Using conjunctive consolidation, a 4-stage clinical severity staging system that incorporates clinical symptoms and tumor size at presentation was created to predict severe complications.
- The clinical severity staging system demonstrated an improvement in the ability to discriminate severe complications (C index, 0.754; 95% CI, 0.67-0.84) from a model of tumor size alone (C index, 0.706; 95% CI 0.62-0.79)
This study found that, for patients with VS, the combination of hearing loss at presentation, vestibular symptoms, and tumor size is associated with the development of severe surgical complications. Using these symptoms and tumor sizewithin a logistic regression model, a clinically meaningful difference between groups was defined. The development of this model illustrates the potential benefit of integrating these clinical features with tumor size for prognostic models for patients with VS considering surgery.
Among patients with VS, symptoms present at initial preoperative evaluation add to the impact of tumor size in determining the risk of severe postoperative complications. A new CSSS is proposed that incorporates preoperative symptoms with tumor size to help identify patients at risk for severe complications. Prospective studies are needed to validate and potentially extend this model to a variety of other outcomes for patients with VS.
Description of Clavien-Dindo Surgical Complications
Grade Definition and scoring system details
Grade I Any deviation from the normal postoperative course without the need for pharmacologic treatment or surgical, endoscopic, and radiologic interventions Allowed therapeutic regimens are drugs such as antiemetics, antipyretics, analgesics, diuretics, and electrolytes, and physiotherapy. This grade also includes wound infections opened at the bedside
Grade II Requiring pharmacologic treatment with drugs other than those allowed for grade I complications
Blood transfusions and total parenteral nutrition are also included
Grade III Requiring surgical, endoscopic, or radiologic intervention
IIIa Intervention not under general anesthesia
IIIb Intervention under general anesthesia
Grade IV Life-threatening complication (including CNS complications) requiring IC/ICU managementa
IVa Single-organ dysfunction (including dialysis)
IVb Multiorgan dysfunction
Grade V Death of a patient