Retrosigmoid Intradural Suprameatal-Inframeatal Approach for Complete Surgical Removal of a Giant Recurrent Vestibular Schwannoma with Severe Petrous Bone Involvement: Technical Case Report.
Surgical removal of giant vestibular schwannomas with severe petrous bone involvement remains challenging due to the high risk of complications. The retrosigmoid intradural suprameatal-inframeatal approach (RISIA) allows for safe exposure extending from Meckel's cave to the petrous internal carotid artery (ICA). CASE DESCRIPTION: A 27-year-old man presented with recurrence of a giant vestibular schwannoma (4.5 cm) invading Meckel's cave and the left petrous ICA. Symptoms included complete left facial palsy and hearing loss due to tumor invasion and previous operations, as well as left-sided trigeminal hypesthesia, abducens nerve palsy, and lower cranial nerve dysfunction due to tumor compression. The patient also exhibited severe discoordination and ataxia. The tumor was completely resected via the RISIA, which involved drilling of the suprameatal and inframeatal portions of the petrous bone. No approach-related complications were observed. Full recovery of cranial nerve functions (with the exception of those related to the facial and cochlear nerves) and balance were observed postoperatively. CONCLUSIONS: The RISIA allows for safe and effective surgical access during complete tumor resection, even when severe involvement of Meckel's cave and the petrous ICA are observed. The present report is the first to demonstrate the usefulness of this approach in patients with recurrent giant vestibular schwannoma.
Microsurgery management of vestibular schwannomas in neurofibromatosis type 2: indications and results.
Aim:To analyze the senior author's experience and strategy of treatment of patients with neurofibromatosis type 2 (NF2), with particular emphasis on vestibular schwannoma (VS) surgery.
MATERIALS AND METHODS: Over a period of more than 35 years, the senior author (M.S.) has operated on more than 165 patients with NF2. The total number of VS surgeries was 210. This retrospective analysis includes 145 consecutively operated patients. Medical records, operative reports, follow-up neurological, audiometric examinations, and neuroradiological findings were analyzed. RESULTS: Total tumor removal was achieved in 85% of the operated tumors. In 15%, deliberately subtotal removal was performed for brain stem decompression and hearing preservation in the only hearing ear. The overall rate of hearing preservation was 35%. When only patients with preserved useful preoperative hearing were included, the rate was 65%. Bilateral hearing after surgery was preserved in 23% of the patients. The anatomical integrity of the facial nerve was preserved in 89%.
CONCLUSIONS: The goal of VS surgery in patients with NF2 should be complete removal but not at the expense of functional impairment. Carefully individualized treatment strategy offers the possibility of prolongation of life and preservation of neurological functions.
Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection. Technical note.
Increasing rates of facial and cochlear nerve preservation after vestibular schwannoma surgery have been achieved in the last 30 years. However, the management of a partially or completely damaged facial nerve remains an important issue. In such a case, several immediate or delayed repair techniques have been used. On the basis of recent studies of successful end-to-side neurorrhaphy, the authors applied this technique in a patient with an anatomically preserved but partially injured facial nerve during vestibular schwannoma surgery. The authors interposed a sural nerve graft to reinforce the facial nerve whose partial anatomical continuity had been preserved. On follow-up examinations 18 months after surgery, satisfactory cosmetic results for facial nerve function were observed. The end-to-side interposed nerve graft appears to be a reasonable alternative in cases of partial facial nerve injury, and might be a future therapeutic option for other cranial nerve injuries.
Surgical treatment of patients with vestibular schwannomas after failed previous radiosurgery.
OBJECT: An increasing number of patients with vestibular schwannomas (VSs) are being treated with radiosurgery. Treatment failure or secondary regrowth after radiosurgery, however, has been observed in 2%-9% of patients. In large tumors that compress the brainstem and in patients who experience rapid neurological deterioration, surgical removal is the only reasonable management option. METHODS: The authors evaluated the relevance of previous radiosurgery for the outcome of surgery in a series of 28 patients with VS. The cohort was further subdivided into Group A (radiosurgery prior to surgery) and Group B (partial tumor removal followed by radiosurgery prior to current surgery). The functional and general outcomes in these 2 groups were compared with those in a control group (no previous treatment, matched characteristics). RESULTS： There were 15 patients in Group A, 13 in Group B, and 30 in the control group. The indications for surgery were sustained tumor enlargement and progression of neurological symptoms in 12 patients, sustained tumor enlargement in 15 patients, and worsening of neurological symptoms without evidence of tumor growth in 1 patient. Total tumor removal was achieved in all patients in Groups A and B and in 96.7% of those in the control group. There were no deaths in any group. Although no significant differences in the neurological morbidity or complication rates after surgery were noted, the risk of new cranial nerve deficits and CSF leakage was highest in patients in Group B. Patients who underwent previous radiosurgical treatment (Groups A and B) tended to be at higher risk of developing postoperative hematomas in the tumor bed or cerebellum. The rate of facial nerve anatomical preservation was highest in those patients who were not treated previously (93.3%) and decreased to 86.7% in the patients in Group A and to 61.5% in those in Group B. Facial nerve function at follow-up was found to correlate to the previous treatment; excellent or good function was seen in 87% of the patients from the control group, 78% of those in Group A, and 68% of those in Group B. CONCLUSIONS: Complete microsurgical removal of VSs after failed radiosurgery is possible with an acceptable morbidity rate. The functional outcome, however, tends to be worse than in nontreated patients. Surgery after previous partial tumor removal and radiosurgery is most challenging and related to worse outcome.
Surgery of Vestibular Schwannomas with Peritumoral Edema
脑膜瘤中肿瘤周围水肿的存在与手术的复杂性和预后有关，其在听神经瘤（VS）中的意义尚未得到系统评估。方法：对系列患者进行回顾性研究，将VS瘤周水肿与以下因素进行相关性分析：肿瘤影像学特征、手术难度、肿瘤粘连、血管分布、包膜存在、功能预后和并发症发生率。将实验组结果与没有肿周水肿的对照组进行比较。结果：共有30例患者（30/605例患者或5％）出现肿瘤周围水肿。具有瘤周水肿患者更经常发生耳鸣和脑积水，这些VS常富血供。手术难度与瘤周水肿没有明显重大关系，但和肿瘤的蛛网膜包膜相关。 A组的所有患者均实现了完全切除（对照组为97％）。面部神经保留率为97％（原为98％）。两组的功能结局相似。但是，对照组的术后血肿发生率更高（10％vs. 3％）。结论：伴有局灶性瘤周水肿的VS更富血供，应警惕其术后更高的出血风险。但是，以精良的显微手术技术为前提，肿周水肿的存在不会影响肿瘤全切率及术后功能。
Introduction: The presence of peritumoral edema in meningiomas correlates with complexity of surgery and outcome. Its significance in vestibular schwannomas (VS) has not yet been evaluated systematically. Methods: Retrospective study of patients’ series. Correlative analysis of presence of edema to: radiological tumor characteristics, operative difficulty, tumor adhesion, vascularity, presence of capsule, functional outcome, and complication rate. The findings were compared with those in a matched control group without peritumoral edema (group B). Results: A total of 30 patients (30/605 patients or 5%) presented with peritumoral edema. Patients with edema had more frequently tinnitus and hydrocephalus. At surgery these VS were more frequently hypervascular. No major difference in the operative difficulty in patients with/without edema in regards to difficulty of tumor dissection and presence of arachnoid plane was found. Complete resection was achieved in all patients in group A (vs.97% in the control group B); the facial nerve was preserved in 97% (vs.98%). Functional outcome in both groups was similar. However, the postoperative hemorrhage rate was higher in the current control Group (10 vs. 3%). Conclusion: VS with perifocal edema are more frequently hypervascular. This may lead to a higher rate of postoperative hemorrhages in the tumor bed and should always be considered. With adequate microsurgical technique, however, the presence of peritumoral edema does not influence the rate of complete tumor removal and the functional outcome.
1. Sato Y, Mizutani T, Shimizu K, Freund HJ, Samii M. Retrosigmoid Intradural Suprameatal-Inframeatal Approach for Complete Surgical Removal of a Giant Recurrent Vestibular Schwannoma with Severe Petrous Bone Involvement: Technical Case Report. World Neurosurg. 2018;110:93-8.
2. Samii M, Gerganov V, Samii A. Microsurgery Management of Vestibular Schwannomas in Neurofibromatosis Type 2: Indications and Results. 2008;21:169-75.
3. Samii M, Koerbel A, Safavi-Abbasi S, Di Rocco F, Gharabaghi A. Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection. Technical note. Journal of Neurosurgery. 2006;105(6):920-3.
4. Gerganov V, Giordano M, Samii M. Surgical treatment of patients with vestibular schwannomas after failed previous radiosurgery. Journal of Neurosurgery. 2012;116(4):713-20.
5. Gerganov V, Giordano MG, Metwalli H, Samii A, Samii M. Surgery of Vestibular Schwannomas with Peritumoral Edema. Journal of Neurological Surgery Part B: Skull Base. 2014;75(S 02):a064.