Use of flexible CO₂ laser fiber in microsurgery for vestibular schwannoma via the middle cranial fossa approach.

The aim of this study was to analyze the results of microsurgery in vestibular schwannomas (VS) with assistance of a flexible CO(2) laser fiber (Omniguide(®)) using the middle cranial fossa (MCF) approach. For that purpose we performed a prospective non-randomized clinical trial. In 20 consecutive patients suffering from VS and elected for microsurgery via the MCF approach, tumor resection was performed with the aid of the flexible CO(2) laser ("laser group", LG). Twenty patients with similar tumor volume and pre-operative hearing status out of a cohort of 76 patients previously treated by the same surgeon without laser were used as comparison group ("conventional group", CG) (matched-pair-technique). Facial weakness (House-Brackmann (HB) 2-4) was seen in early postoperative (p.o.) days in six patients in each group and all recovered completely by 3 months p.o., except one patient with HB 2 in CG. Facial nerve preservation rate (HB 1 + 2) was 100% in both groups. Hearing preservation rate (Gardner/Robertson class 1 + 2 or AAO-HNS A + B, pre- and postoperatively) was 72% in LG and 82% in CG, without significant difference. Overall time from incision to skin suture was 157 min (SD 55.9) in CG and 160 min (SD 39.7) in LG. Tumor preparation time was 23.2 min (SD 19.7) in CG and 36.1 min (SD 33.8) in LG. The use of a handheld flexible CO(2) laser fiber in VS-microsurgery is safe and subjectively facilitates tumor resection especially in "difficult" (e.g., highly vascularized) tumors. However, in this limited prospective trial the excellent functional outcome following conventional microsurgery could not be further improved, nor the surgical time reduced by means of the non-contact laser-tool. Focusing the use of the flexible CO(2) laser on "difficult" tumors may lead to different results in future.