[Anesthesiological methods in acoustic neuroma surgery using the translabyrinthine approach]

Removal of acoustic neuromas may often imply anesthesiological as well as surgical problems, especially in the case of large tumors (> 3 cm) which may have come into contact with vital neighbouring structures (brain stem, cerebellum). In this paper the use of two different anesthesiological methods during the translabyrinthine approach is analyzed and discussed in the light of the different needs in this type of surgery. More specifically, anesthesia maintenance was assured by constant infusion of either Propofol (4 mg/kg/h) or Isoflurane (1-1.5%). Withdrawal of curarization was also planned in order to allow the surgeon to take advantage of routine intraoperative facial nerve monitoring. Arterial pressure, CO2 and O2 were assessed at prefixed phases of the operation. Both anesthesiologic methods proved to be satisfactory during the entire surgical procedure. During dissection of the tumoral capsule, an increased heart rate (7% of the initial value) was noticed, whilst in only three patients (with tumors larger than 3.5 cm) a severe bradycardia, which did not respond to Atropine administration and which subsided spontaneously during temporary suspension of surgical manoeuvres, occurred. After this preliminary experience, the Authors believe that both techniques could have a major role in translabyrinthine acoustic tumor surgery and auspicate their further application.