Microsurgical removal of vestibular schwannomas with flexible hand-held 2μ-Thulium-fiber laser. Personal experience in 78 consecutive cases

Aims: We performed a retrospective non-randomized study to analyze the results of microsurgery of vestibular schwannomas (VS) using 2μ-Thulium flexible hand-held laser fiber (Revolix jr®). Methods: From September 2010 to November 2018, 180 patients suffering from VS have been operated on with microsurgical technique via retrosigmoid (RS) approach in our Department. From July 2012 to April 2018, tumor resection was performed in 78 cases with the assistance of 2μ-Thulium-fiber hand-held flexible laser. Facial nerve function was assessed with the House-Brackmann (HB) scale preoperatively, 1 week postoperatively, and 6-month after surgery. Results: Overall time from incision to skin suture changed in relation to size of tumor (185–575 min) and was not affected by the use of laser. In 5 out of 78 cases preoperative facial nerve palsy HB2 and in one case HB4 (permanent) was observed. On considering 77 cases (excluding 1 permanent HB4) with a minimum 6-month follow-up, facial nerve preservation rate (HB1) was 92,2%. Hearing preservation rate (AAO-HNS A/B classes) was possible in 17 out of 30 cases (56,7%). Adopting a 0–3-scale, the mean surgeon satisfaction rate of usefulness of laser fiber was 2,75. Conclusions: The use of 2μ-Thulium-fiber hand-held flexible laser in VS-microsurgery seems to be safe and to facilitate tumor resection, especially in “difficult” conditions (e.g., highly vascularized and hard tumors). In this retrospective trial, the good functional outcome following conventional microsurgery had not further improved, nor the surgical time reduced by laser. Focusing its use on “difficult” (large and vascularized) cases may lead to different results in future. Keywords: Acoustic neuroma, Facial nerve preservation, Hearing preservation, Retrosigmoid approach, 2μ-Thulium laser, Vestibular schwannom

Prophylactic effect of topical diluted papaverine in preventing hearing loss during microvascular decompression for typical trigeminal neuralgia: Case report and technical note

Background and objective: Papaverine hydrochloride is a direct-acting vasodilator used to manage vasospasm during various neurosurgical operations. Transient hearing loss due to vasospasm of Internal auditory artery during Posterior Fossa Microvascular Decompression (MVD) for Typical Trigeminal Neuralgia (TTN) is one of possible complications of this surgical procedure. The aim of this technical note is to underline the potential efficacy of the use of intracisternal diluted papaverine and its proper use. Materials and methods: BAEP is routinely used to monitoring functionality of vestibulocochlear nerve during MVD for TTN. In one patient recently operated on, during arachnoid dissection BAEP showed a lag of V wave of 1 ms, likely due to vasospasm of Internal Auditory Artery (IAA) probably caused by arachnoid traction. Intracisternal injection of pure papaverine without excipients (60 mg/2 ml) diluted in 20 cm3 of 0,9% saline solution (0,3%) was used as a direct therapeutic action to manage vasospasm of IAA artery. Results: Few minutes after the intracisternal injection of diluted papaverine, BAEP's wave V started to get back to normal length and at the end of procedure was the same evoked before starting MVD. After surgery hearing was bilaterally normal. Conclusions: There is large uncertainty about dose-related efficacy and side effects of intracisternal papaverine (iPPV). Dilution of papaverine in saline is recommended to avoid complications. In our practice, in line with the literature, we use 0,3% diluted pure papaverine to prevent hearing loss during MVD for TTN. Keywords: ABR, Hearing preservation, Microvascular decompression, Retrosigmoid approach, Trigeminal neuralgi