Hearing Preservation in Acoustic Neuroma Surgery

Abstract

Hearing preservation remains difficult and challenging in acoustic neuroma surgery. Our personal experience with acoustic neuroma surgery comprises 1200 cases over the past two decades. We analyzed the recent series of 522 patients with acoustic neuroma over the past 7 years. Our operative results demonstrated that hearing preservation rate was 74% in 105 cases of small acoustic neuromas (< 1.5 cm) and hearing preservation was possible even in larger acoustic neuromas (> 2 cm) at 60%. Hearing preservation in surgery of larger acoustic neuromas is feasible. The most important factor for hearing preservation is a bloodless, precise, and meticulous sharp dissection technique. Of 105 small acoustic neuromas, 29 patients underwent middle fossa surgery, and 76 were operated upon through a retromastoid approach. Good hearing function in Class A or B was preserved in 74.1% of cases. Follow-up facial nerve function was similar in both middle fossa and retromastoid approaches; however, the retromastoid-retrosigmoid approach provided easier operative approach, shorter operative time, less blood loss, and a shorter hospital stay. The middle fossa approach has the disadvantage of more frequent temporary facial nerve weakness and occasional temporal lobe edema associated with more blood loss and a longer hospital stay. In obtaining similar operative results, surgeons should select the safer and easier operative method; therefore, for surgery of smaller acoustic neuromas we recommend the simple retromastoid approach rather than complex middle fossa approach. The key points of microsurgical approaches, dissection techniques, and the use of specially designed supermicro cerebellopontine angle dissectors will be discussed with presentation of DVD videos.