Postoperative Hearing Preservation in Patients Undergoing Retrosigmoid Craniotomy for Resection of Vestibular Schwannomas: A Systematic Review of 2034 Patients

Abstract

BACKGROUND Vestibular schwannomas (VS) are benign tumors derived from Schwann cells ensheathing the vestibulocochlear nerve. The retrosigmoid (RS) surgical approach is useful to resect tumors of multiple sizes while affording the possibility of preserving postoperative hearing. OBJECTIVE To conduct a systematic review of published literature investigating hearing preservation rates in patients who underwent the RS approach for VS treatment. METHODS The PubMed, Scopus, and Embase databases were surveyed for studies that reported preoperative and postoperative hearing grades on VS patients who underwent RS treatment. Hearing preservation rates were calculated, and additional patient demographic data were extracted. Tumor size data were stratified to compare hearing preservation rates after surgery for intracanalicular, small (0-20 mm), and large (>20 mm) tumors. RESULTS Of 383 deduplicated articles, 26 studies (6.8%) met eligibility criteria for a total of 2034 patients with serviceable preoperative hearing, for whom postoperative hearing status was evaluated. Aggregate hearing preservation was 31% and 35% under a fixed and random effects model, respectively. A mixed effects model was used to determine hearing preservation rates depending on tumor size, which were determined to be 57%, 37%, and 12% for intracanalicular, small, and large tumors, respectively. Significant cross-study heterogeneity was found (I2 = 93%, τ2 = .964, P < .01; Q = 287.80, P = < .001), with rates of hearing preservation ranging from 0% to 100%. CONCLUSION Tumor size may have an effect on hearing preservation rates, but multiple factors should be considered. Discussion of a patient's expectations for hearing preservation is critical when deciding on VS treatment plans.

Preoperative Radiographic Predictors of Hearing Preservation After Retrosigmoid Resection of Vestibular Schwannomas

“…16,[27][28][29] In a recent systematic review, a generalized linear mixed model was developed to compare HP among intracanalicular, small (\20 mm), and large (20 mm) tumors. 30 Statistically significant differences were observed: HP was 57% for intracanalicular tumors, 37% for small tumors, and 12.3% for larger tumors. Our data are in line with these observations and highlight the favorable hearing outcomes for younger patients with very small tumors (\5 mm).…”

Analysis of Hearing Preservation in Middle Cranial Fossa Resection of Vestibular Schwannoma

“…Preoperative counseling included discussion of all treatment options including observation with surveillance audiometry and MRI, stereotactic radiation, and microsurgical resection. Patients deemed audiometrically fit for attempted hearing preservation resection under the guidelines of American Academy of Otolaryngology-Head and Neck Surgery (AAO) (19) class C hearing were offered the option of the MCF or RS approach (15). All patients underwent a hearing preservation MCF approach for VS resection with continuous intraoperative brainstem response monitoring.…”

“…In studies addressing hearing preservation in microsurgical resection, factors such as tumor size, rate of growth, preoperative WRS and/or pure tone thresholds can contribute to the likelihood of HP (11)(12)(13)(14)(15)(16). Diagnosis of VS can be the source of considerable anxiety and VS patients perceive a lower general quality of life (QOL) compared to patient groups with other illnesses (17).…”

Kontinuitätserhalt des Nervus cochlearis bei der retrosigmoidalen ablativen Osteotomie des inneren Gehörgangs bei fortgeschrittenen Vestibularisschwannomen

“…Eine Domäne der HNOKHC beim retrosigmoidalen Zugangsweg ist dabei die endokranielle chirurgische Exploration des inneren Gehörgangs („internal acoustic canal“, IAC) über eine ablative Osteotomie. Die Kenntnis der bei jedem Patienten individuell räumlichen Projektion des knöchern eingebetteten hinteren Bogengangs („posterior semicircular canal“, PSC) zum IAC sowie der durch das intrameatale Tumorwachstum veränderte, teilweise prolongierte und lokal verlagerte Verlauf der 4 Nervenstrukturen des Nc, Nervus vestibularis inferior (Nvi) und superior (Nvs) sowie des Nf sind für den Funktionserhalt des Hörens und der Gesichtsmuskulatur entscheidend [ 3 , 5 , 20 , 23 , 27 ]. Eine Analyse der präoperativen hochauflösenden Computertomographie („high resolution computed tomography“, HRCT) des Felsenbeins (0,4 bis 0,6 mm Schichtdicke) sowie die der 3‑D-CISS-Sequenzen in der T2-Gewichtung in der MRT jeweils in 0,5- oder 0,7-mm-Schichtung sollen dazu erste Hinweise geben.…”