How I Do It: The Role of Flexible Hand-held 2µ-Thulium Laser Fiber in Microsurgical Removal of Acoustic Neuromas.

Aims We performed a retrospective nonrandomized study to analyze the results of microsurgery of acoustic neuromas (AN) using 2µ-thulium flexible hand-held laser fiber (Revolix jr). Methods From September 2010 to September 2015, 89 patients suffering from AN have been operated on with microsurgical technique via retrosigmoid approach. In 37 cases, tumor resection was performed with the assistance of 2µ-thulium flexible hand-held laser fiber (L-group). Eight cases operated on with the assistance of CO 2 hand-held flexible laser fiber were excluded from this study. A total of 44 patients, operated on without laser assistance during the same period, were used as comparison group (C-group) (matched pair technique). Facial nerve function was assessed with the House-Brackmann (HB) scale preoperatively, and 1 week and 6 months postoperatively. Results Overall time from incision to skin suture changed in relation to size of tumor (165-575 minutes) and was not affected by the use of laser. In 7 out of 81 cases, a preoperative facial nerve palsy HB2 and in 1 case, HB4 (permanent) were observed. In the remaining 80 cases, at 6-month follow-up, facial nerve preservation rate (HB1) was 92.5%. Hearing preservation rate (AAO-HNS A/B classes) was 68.2% (26 out of 36). Adopting a 0 to 3 scale, the mean surgeon satisfaction rate of usefulness of laser fiber was 2.7. Conclusion The use of 2µ-thulium hand-held flexible laser fiber in AN microsurgery seems to be safe and subjectively facilitates tumor resection especially in "difficult" conditions (e.g., highly vascularized and hard tumors). In this limited 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.

Position and Course of Facial Nerve and Postoperative Facial Nerve Results in Vestibular Schwannoma Microsurgery.

OBJECTIVE: To investigate the variation in the position and course of the facial nerve (FN) in patients undergoing vestibular schwannoma (VS) microsurgery by the keyhole retrosigmoid approach and the relationship between FN position and postoperative facial results. METHODS: The series consists of 100 patients who underwent VS microsurgery during a 5-year period in whom the position and course of the FN could be confirmed by direct stimulation. The course of the FN was classified into 4 patterns according to its position: anterior (ventral) surface of the tumor (A), anterior-superior (AS), anterior-inferior (AI), and dorsal (D). RESULTS: The distribution of patterns was as follows: AS in 48 cases, A in 31, AI in 21, and D in zero. For tumors <1.5 cm, the AS pattern was most common (68.4%). For tumors ≥1.5 cm, the proportion of A and AI positions increased (31.4% and 25.5%). Significant differences were observed between position and course patterns of the FN and postoperative nerve results. Patients with AS and AI patterns had better House-Brackmann FN function compared with patients with the A pattern (P < 0.05). Moreover, in tumors >3.0 cm, the FN tended to adhere strongly to the tumor capsule, and postoperative facial deficits were more frequent (P < 0.05). CONCLUSIONS: The AS pattern was most common for smaller VSs. The A position and course and adhesion of the FN to the tumor capsule were the 2 factors most strongly associated with worse postoperative FN result.

Safety and usefulness of flexible hand-held laser fibers in microsurgical removal of acoustic neuromas (vestibular schwannomas).

AIMS: We performed a retrospective non-randomized study to analyze the results of microsurgery of acoustic neuromas (AN) using two different flexible hand-held laser fibers, CO2 (Omniguide(®)) and 2µ-Thulium (Revolix jr(®)). METHODS: From September 2010 to June 2015, 84 patients suffering from AN have been operated on with microsurgical technique via retrosigmoid (RS) approach. In 42 cases tumor resection was performed with the assistance of hand-held flexible laser (L-group): in 8 cases CO2-fiber and in 34 2µ-Thulium-fiber. Fortytwo patients, operated on without laser-assistance, were used as comparison group (C-group) (matched-pair-technique). Facial nerve function was assessed with the House-Brackmann (HB) scale preoperatively, 1 week postoperatively, and 6-month or more after surgery. RESULTS: Overall time from incision to skin suture changed in relation to size of tumor (165-575min) and was not affected by the use of laser. In 2 cases preoperative facial nerve palsy was observed. In the remaining 82 cases, at 6-month follow-up facial nerve preservation rate (HB I) was 90.2%. Hearing preservation rate (AAO-HNS A/B classes) was 68.4% (26 out of 38). Adopting a 0-3-scale, the mean surgeon satisfaction rate of usefulness of laser fiber was 2.64. CONCLUSIONS: The use of a hand-held flexible laser fiber in AN-microsurgery seems to be safe and subjectively facilitates tumor resection especially in "difficult" conditions (e.g., highly vascularized and hard tumors). In this limited 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.

Underlay hourglass-shaped autologous pericranium duraplasty in "key-hole" retrosigmoid approach surgery: Technical report.

BACKGROUND: Cerebrospinal fluid (CSF) leakages represent a major complication of skull base surgery. Watertight dural suture is challenging, and different ways to reinforce it have been proposed. Since 6 months, we use locally harvested autologous pericranium graft for dural repair in retrosigmoid approach. METHODS: Retrospectively, we analyzed 27 patients operated on with key-hole retrosigmoid approach from May 2014. In all, autologous pericranium was harvested and inserted as an underlay "hourglass-shaped" plug under the dura plane and stitched to dura. Surgical patch and sealant were used for augmentation. Complications considered were new neurological symptoms, surgical site infections, meningitis, CSF-leaks, and pseudomeningocele. RESULTS: Indications included tumor (16 cases), microvascular decompression (10 cases), and hemorrhagic cerebellar arteriovenous malformation (1 case). Surgical site infections, meningitis, and CSF leaks have never been observed. One neurofibromatosis type 2 patient operated on for large acoustic neuroma developed an asymptomatic pseudomeningocele, disappeared on 3-month magnetic resonance imaging follow-up. CONCLUSIONS: In our series, autologous pericranium inserted and stitched as an underlay hourglass-shaped plug, augmented with surgical patch pieces and dural sealant seemed to be safe and effective for dural repair in "key-hole" retrosigmoid approach. With this technique, we obtained low complication rate, similar to the best current results of available literature.