The learning curve in post-operative hearing results in vestibular schwannoma surgery

• Published in: Auris Nasus Larynx Vol. 28; no. 3; pp. 209 - 213
• Main Authors: Kanzaki, Jin, Inoue, Yasuhiro, Ogawa, Kaoru
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ireland Ltd 01.08.2001; Elsevier BV
• Subjects: Adolescent; Adult; Audiometry, Evoked Response; Audiometry, Evoked Response - methods; Audiometry, Pure-Tone; Audiometry, Pure-Tone - methods; Ear Neoplasms; Ear Neoplasms - complications; Ear Neoplasms - surgery; Ear, Inner; Ear, Inner - diagnostic imaging; Ear, Inner - pathology; Ear, Inner - surgery; Evoked Potentials, Auditory, Brain Stem; Evoked Potentials, Auditory, Brain Stem - physiology; Female; Hearing Disorders; Hearing Disorders - diagnosis; Hearing Disorders - etiology; Hearing preservation; Humans; Learning curve; Magnetic Resonance Imaging; Male; Middle Aged; Monitoring, Intraoperative; Neoplasm Invasiveness; Neoplasm Staging; Neuroma, Acoustic; Neuroma, Acoustic - complications; Neuroma, Acoustic - diagnosis; Neuroma, Acoustic - surgery; Otologic Surgical Procedures; Otologic Surgical Procedures - methods; Postoperative Care; Preoperative Care; Quality of hearing; Severity of Illness Index; Time Factors; Tomography, X-Ray Computed; Vestibular schwannoma; Quality of hearing; Learning curve; Hearing preservation; Vestibular schwannoma
• ISSN: 0385-8146; 1879-1476
• DOI: 10.1016/S0385-8146(01)00086-4

Purpose: We chronologically investigated whether the hearing preservation (HP) rate improved or not in vestibular schwannoma (VS) surgery. Subjects and methods: HP surgery has been attempted in 127 VS patients with pre-operative class A and B hearing from 1976 to 1999. The HP rate was chronologically compared with hearing level and tumor size. Results: The preservation rate of pre-operative class A hearing which was preserved post-operatively as class A has recently been increasing especially in patients with an intracanalicular (IC) tumor. This rate was improved to 67% from 1995, although this was 33% from 1989 to 1994. However, the preservation rate of pre-operative class B in patients with an IC tumor and that of pre-operative class A hearing which was preserved as class A in patients with a larger tumor extending into the posterior fossa, have not improved over the last 10 years. Conclusion: These results indicate that the improvement of the HP rate is mainly due to the increased number of patients with an IC tumor with class A pre-operative hearing. In patients with a tumor of 4–20 mm in size, especially in those showing pre-operative class B hearing, there may be histologically some limitations such as gliosis in the cochlear nerve in the preservation rate of good quality (class A or B) of hearing.