Microsurgical Removal of Olfactory Groove Meningiomas via the Pterional Approach

Commonly used frontobasal approaches for microsurgical removal of olfactory groove meningiomas have certain disadvantages, such as late exposure of the neurovascular complex located dorsal to the tumor, namely, the internal carotid artery, middle cerebral artery, anterior cerebral artery, and the optic nerves. In addition, the frontal sinuses are frequently opened and there can be compression of the frontal lobes from significant spatula pressure. We report our experience with the pterional approach for these tumors in 28 patients. All patients presented with hyposmia/anosmia; 20 had personality changes and 8 had visual deficits. At surgery, after dissection of the sylvian fissure, the internal carotid artery, middle cerebral artery, anterior cerebral artery, and the homolateral optic nerve were exposed before removal of the posterior tumor parts. Reduction of focal pressure was achieved by removal of the contralateral tumor following partial resection of the falx and crista galli. Total tumor removal was obtained in all but 1 patient. One patient died of pulmonary embolism. The psychoorganic syndrome resolved in all but 1 patient; visual deficits improved in 6 patients. There were no postoperative infections. We consider the pterional approach to be superior to others for these lesions because it provides early exposure of the neurovascular complex, preservation of the frontal venous drainage, and avoidance of postoperative cerebrospinal fluid fistulae.     

Microsurgical Removal of Olfactory Groove Meningiomas via the Pterional Approach

Commonly used frontobasal approaches for microsurgical removal of olfactory groove meningiomas have certain disadvantages, such as late exposure of the neurovascular complex located dorsal to the tumor, namely, the internal carotid artery, middle cerebral artery, anterior cerebral artery, and the optic nerves. In addition, the frontal sinuses are frequently opened and there can be compression of the frontal lobes from significant spatula pressure. We report our experience with the pterional approach for these tumors in 28 patients. All patients presented with hyposmia/anosmia; 20 had personality changes and 8 had visual deficits. At surgery, after dissection of the sylvian fissure, the internal carotid artery, middle cerebral artery, anterior cerebral artery, and the homolateral optic nerve were exposed before removal of the posterior tumor parts. Reduction of focal pressure was achieved by removal of the contralateral tumor following partial resection of the falx and crista galli. Total tumor removal was obtained in all but 1 patient. One patient died of pulmonary embolism. The psychoorganic syndrome resolved in all but 1 patient; visual deficits improved in 6 patients. There were no postoperative infections. We consider the pterional approach to be superior to others for these lesions because it provides early exposure of the neurovascular complex, preservation of the frontal venous drainage, and avoidance of postoperative cerebrospinal fluid fistulae.     

Presentation and Patterns of Late Recurrence of Olfactory Groove Meningiomas

The objective of this article is to present the recurrence pattern of olfactory groove meningiomas after surgical resection. Four patients, one female and three males, with surgically resected olfactory groove meningiomas presented with tumor recurrence. All patients underwent resection of an olfactory groove meningioma and later presented with recurrent tumors. The mean age at initial diagnosis was 47 years. All presented initially with vision changes, anosmia, memory dysfunction, and personality changes. Three patients had a preoperative MRI scan. All patients had a craniotomy, with gross total resection achieved in three, and 90% tumor removal achieved in the fourth. Involved dura was coagulated, but not resected, in all cases. Three patients were followed with routine head CT scans postoperatively, and none was followed with MRI scan. The mean time to recurrence was 6 years. Three patients presented with recurrent visual deterioration, and one presented with symptoms of nasal obstruction. Postoperative CT scans failed to document early tumor recurrence, whereas MRI documented tumor recurrence in all patients. Tumor resection and optic nerve decompression improved vision in two patients and stabilized vision in two. Complete resection was not possible because of extensive bony involvement around the anterior clinoid and inferior to the anterior cranial fossa in all cases. Evaluation of four patients with recurrent growth of olfactory groove meningiomas showed the epicenter of recurrence to be inferior to the anterior cranial fossa, with posterior extension involving the optic canals, leading to visual deterioration. This location led to a delay in diagnosis in patients who were followed only with routine CT scans. Initial surgical procedures should include removal of involved dura and bone, and follow-up evaluation should include formal ophthalmologic evaluations and routine head MRI scans.     

The Role of the Pterional Approach in the Surgical Treatment of Olfactory Groove Meningiomas: A 20-year Experience

Background Olfactory groove meningiomas remain surgically challenging. The common microsurgical approaches suffer from late exposure of the neurovascular structures. Conversely, the pterional approach has the advantage of early dissection of the posterior neurovascular complex.Methods We reviewed the records of patients treated for olfactory groove meningioma in our department between 1991 and 2010. A total of 61 patients underwent removal of olfactory groove meningiomas via the pterional approach. These included 58 primary and 3 recurrent tumors. Mean overall follow-up time was 122 months.Results Early exposure and dissection of the internal carotid artery, middle cerebral artery, anterior cerebral artery, and optic nerve was feasible in all cases. Complete tumor removal was achieved in 60 patients. Morbidity and mortality rates were 26% and 1.6% respectively. Postoperative complications included epileptic seizures (five patients) and cerebrospinal fluid (CSF) leak (two patients). During follow-up, we recorded three tumor recurrences.Conclusions The pterional approach appears to be an excellent solution for the treatment of olfactory groove meningiomas. Its foremost advantage is early visualization of the posterior neurovascular complex. Moreover, it allows frontal sinus preservation and timely tumor devascularization and avoids excessive brain retraction. The pterional view is familiar to most neurosurgeons and therefore the transition to this technique is fairly straightforward.     

神经内镜辅助眶上锁孔入路治疗巨大嗅沟脑膜瘤

目的探讨神经内镜辅助眶上锁孔入路治疗巨大嗅沟脑膜瘤的手术效果及手术技巧。方法采用内镜辅助、眶上锁孔入路（显微手术）治疗12例巨大（≥7cm）嗅沟脑膜瘤。结果肿瘤全切除9例（SimpsonⅠ级切除5例，Ⅱ级切除4例），次全切除（SimpsonⅢ级切除）3例。无手术死亡。10例随访3个月～2年，平均14个月。9例恢复正常生活，1例生活能自理。NRI随访9例，肿瘤无复发。结论利用神经内镜辅助及显微外科技术，采用眶上锁孔入路、对肿瘤进行分块切除治疗巨大嗅沟脑膜瘤，手术创伤小，疗效满意。     

Giant Olfactory Meningiomas: The Pterional Approach and Its Relevance for Minimizing Surgical Morbidity

Olfactory groove meningiomas may attain surprisingly large size. The subfrontal approach is currently the route preferred by most neurosurgeons for their excision. The pterional-transsylvian route represents an alternate exposure for microsurgery of frontobasal tumors. Although this approach has been already described for olfactory meningiomas, tumors of giant size were not specifically addressed in the literature. We report the application of the pterional-transsylvian approach in six patients with giant olfactory meningiomas. This series is unique because it includes only patients with tumors exceeding 6 cm in diameter with bilateral symmetrical development. A radical removal was achieved in all patients and all of them made a full recovery. To investigate the relevance of the pterional-transsylvian approach for minimizing surgical morbidity, a magnetic resonance imaging protocol was designed to characterize even subtle postoperative frontal lobe structural changes. These changes, limited to the frontal lobe ipsilateral to exposure and localized in specific anatomical domains of the prefrontal area, included cystic degenerative alterations, parenchymal gliosis, and associated persistent white matter edema. Results from the present series strengthen the usefulness of the pterional-transsylvian approach as a safe surgical route for lesions affecting the anterior skull base, even with huge bilateral symmetrical expansion, such as giant olfactory meningiomas.     

Transcranial Transsphenoidal Approach for Tuberculum Sellae Meningiomas

Summary  Objective. A series of 21 patients with tuberculum sellae meningioma who received surgical treatment is reported.  Patients and Methods. All 9 females and 12 males (mean age 49 years) presented visual disturbances of varying degrees in either one or both eyes. Eighteen of the tumours were less than 3 cm in size, and 3 were larger. Tumour resection of uniform surgical technique was performed in all cases. Following a bicoronal scalp incision, bifrontal craniotomy combined with removal of the orbital rim bilaterally was performed. The frontal dura was opened bilaterally, and the most anterior portion of the superior sagittal sinus was transected. Bifrontal retraction and arachnoid dissection along the proximal olfactory tracts brought the tumour into view. Additional dissection of the interhemispheric fissure extended the operative field to the anterior communicating artery. The anterior skull base was drilled out to resect the basal part of the tumour. In all cases, the optic canal and sphenoid sinus, and additionally in some cases the ethmoid sinus were opened. The tumour uniformly extended inferomedially to the optic nerve, and direct visualization of this portion of the tumour was possible with our approach. The opened paranasal sinuses were reconstructed with adipose tissue harvested from the patient's abdomen and the pericranial flap.  Results. In all patients, total or almost total resection of the tumour was accomplished. Postoperatively, visual function was improved in 11 patients, was unchanged in 8, and worsened in 2. There were no operative deaths. Cerebrospinal fluid leakage was occurred in two patients but could be conservatively managed. In a mean 3-year follow-up, tumour recurrence was observed in only one patient who presented a malignant histology.  Conclusions. We are confident that our surgical approach has great clinical value in surgical resection of tuberculum sellae meningioma. The good accessibility to a tumour extending inferomedially to the optic nerve should, in particular, be stressed.     

The Middle Fossa Transpetrous Approach for Petroclival Meningiomas

Seventeen patients with petroclival meningioma were operated on through a middle fossa transpetrous approach. This approach exposes the anterior cerebellopontine angle through a middle fossa craniotomy with removal of the petrous apex medial to the cochlea and petrous carotid artery. This approach may be enlarged by transection of the superior petrosal sinus and tentorium. The surgical technique and application of the middle fossa transpetrous approach for petroclival meningiomas is presented.     

Presigmoid Sinus Approach to Petroclival Meningiomas

Between August 1987 and May 1989 five patients with petroclival meningiomas were operated on at the Neurosurgical Clinic of the Krankenhaus Nordstadt. Hannover, Germany, using an original combined supra- and infratentorial presigmoid sinus approach. There were two men and three women, ranging in age from 34 to 61 years (mean, 48 years; median, 46 years). Follow-up ranged between 1 and 22 months. There was no death. Postoperatively, two patients had no useful hearing, one had a permanent facial palsy (the facial nerve had to be sacrificed intraoperatively due to its involvement with tumor), one had a permanent abducens palsy (the VI nerve was involved with tumor and had to be cut). Temporary lower (IX to XII) cranial nerve palsy was observed in all the patients; temporary VI, in two patients; temporary VII, in two patients, temporary hemiparesis, in one patient, temporary gait ataxia, in three patients; and persistent gait ataxia, in one patient. All patients had total tumor removal as assessed at surgery and with postoperative enhanced computed tomography. Four patients were independent and able to carry on normal activity, and one patient was independent at home but not outside due to severe ataxia 4 months after the operation. The presigmoid sinus avenue to the petroclival region shortens the distance to the clivus, permits a multiangled exposure of this difficult surgical area, minimizes the amount of temporal lobe retraction, preserves the integrity of the transverse sinus, and allows for better preservation of the neurovascular structures. These factors translate into a high percentage of total tumor removal and a low incidence of permanent morbidity.     

Resection of Giant Olfactory Groove Meningioma with Extradural Devascularization

A 55-year-old male patient presented with a giant olfactory groove meningioma supplied by both ophthalmic arteries. The tumor was debulked through a bifrontal craniotomy, but the surgery was discontinued because of extensive blood loss. During a second operation, the dura of the frontal base was dissected extradurally before the tumor was removed. The meningeal blood supply was occluded with bipolar coagulation of the epidural meningeal vessels around the crista galli. The highly vascular tumor then was totally removed with considerably less blood loss. The patient's postoperative course was uneventful. Because the ophthalmic artery cannot be embolized preoperatively, the direct extradural approach to the skull base to devascularize the blood supply around the olfactory groove may reduce blood loss and facilitate resection.     

经枕下乙状窦后入路切除桥小脑角脑膜瘤

目的探讨桥小脑角脑膜瘤的临床特点、手术入路及显微手术技巧。方法回顾性分析我院2010年1月~2013年11月间收治的49例桥小脑角脑膜瘤患者的临床资料。所有患者均经枕下乙状窦后入路运用显微技术切除肿瘤。结果肿瘤达SimpsonⅠ级全切除25例(51.0%),Ⅱ级切除17例(34.7%),次全切除7例(14.3%),无手术死亡。随访47例,随访时间平均2.4年(6个月~4年)。37(78.7%)例正常工作,7(14.9%)例能生活自理,3例(6.4%)生活需他人照顾。随访6个月时面听神经功能保留分别为42例(89.4%)与24例(51.1%)。结论枕下乙状窦后入路是切除桥小脑角脑膜瘤非常适宜的入路,术中结合神经电生理监测并合理运用显微技术,能够理想地切除肿瘤和提高患者生存质量。     

神经内镜辅助眶上锁孔入路切除鞍结节脑膜瘤

目的总结内镜辅助下经眶上锁孔入路显微手术切除鞍结节脑膜瘤的手术效果。方法13例鞍结节脑膜瘤采用眶上锁孔入路,先在显微镜直视下切除部分肿瘤,再在内镜辅助下切除残余肿瘤。结果肿瘤全切除12例（SimpsonⅠ级切除2例,Ⅱ级切除10例）,次全切除1例（SimpsonⅢ级切除）。11例术后随访3个月～6年,平均2.3年,〈1年恢复正常工作和生活9例,术后2年肿瘤复发1例,1年后恢复生活自理1例。结论内镜辅助下眶上锁孔入路切除鞍结节脑膜瘤克服了显微镜直视下的盲区,并发症少,创伤小,效果满意。     

Open Frontal Lift: A Conservative Approach

This study aimed to demonstrate that during an open frontal lift, transection of the galea is not necessary. The forehead is elevated, and the ptotic brow is raised after a strip of skin or scalp is removed by folding of the galea. The marcation is penciled on the skin according to the amount of skin–scalp the surgeon estimates it is necessary to remove. Local anesthesia is profusely injected, separating all layers and facilitating surgery. The skin is stripped off the galea, and then through a small incision in the middle, a large dissector separates the galea from the periosteum of the forehead and temporal regions. This dissection can be completed from the temporal area or from the blepharoplasty incisions. With a long pair of scissors, the orbital borders are reached and opened perpendicularly to the bone, releasing the fascia and muscle attachments from the orbital rim without anything being cut. During the coronal approach, once the scalp and forehead are completely mobile, the galea is folded with a continuous running 3/0 Vicryl suture, which after five or six big bites is strongly pulled to fold the galea. The wound then is sutured without tension using staples. When the incision is precapillary, the folding is fixed with Vicryl 3/0 uncolored thread, and the skin is sutured with mononylon 6/0. Complementary corrugator transections are performed from the blepharoplasty incision or by use of the endoscope. With the coronal approach, the surgery requires about 20 min, whereas the precapillary approach requires about 40 min. When only the skin is removed, bleeding is scarce and frontal postoperative edema is minimal. The author has used these techniques in 22 precapillary cases and the intracapillary procedure in 28 cases, some of which had a 4-year follow-up period. With the precapillary approach, temporary paresthesia occurred in some cases, but in all cases, sensibility was recovered within the first 2 to 6 months. With this simple and brief technique, the galea is not transected, no branches of the sensitive nerves are sectioned, and temporal and frontal arteries and veins that supply the scalp are not interrupted. Thereafter, wound healing is fast, allowing a quick recovery without areas of permanent numbness. As a result of this technique, the position of the eyebrows is the same as when frontal lifts are performed with transection of the galea and eversion of the flap, but without the side effects.     

Lateral Suboccipital Retrosigmoid Approach with Tentorial Incision for Petroclival Meningiomas: Technical Note

Introduction The resection of petroclival meningiomas presents great neurosurgical challenges. Although multiple surgical approaches have been developed, the retrosigmoid route tends to be used to address tumors that are predominantly located in the posterior fossa. Our modification of the lateral suboccipital retrosigmoid approach with the placement of a tentorial incision yields good visualization of the supratentorial part of the tumor around the midbrain. Methods We treated four patients, one with primary and three with recurrent petroclival meningioma, by our modified approach. After lateral suboccipital craniotomy, the infratentorial part of the tumor was removed after detaching it from the tentorial surface. The cerebellar tentorium was then carefully incised from the supracerebellar angle, taking care not to damage the superior cerebellar artery and trochlear nerve. Results The operative field surrounding the midbrain was widened by this procedure, and safe dissection of the tumor from the brainstem and other neurovascular structures was performed with direct observation of the interface. Conclusions Our approach is a useful modification of the retrosigmoid approach to petroclival meningiomas. It facilitates the safe resection of the supratentorial part of the tumor in the ambient cistern behind the tentorium.     

Solitary Schwannoma of the Olfactory Groove: Case Report and Review of the Literature

Schwannomas of the olfactory groove are rare tumors. Only 10 have been reported in the past century. The case of a 59-year-old woman with an isolated olfactory schwannoma with cribriform plate erosion is presented.