BACKGROUND: In recent years some reports have been published propagating microsurgical resection of ventral foramen magnum meningiomas (VFMMs). Operative approaches to these lesions have been studied by various author...BACKGROUND: In recent years some reports have been published propagating microsurgical resection of ventral foramen magnum meningiomas (VFMMs). Operative approaches to these lesions have been studied by various authors, but remain controversial. OBJECTIVE: To discuss the operative technique and outcome in patients with VFMMs who had been treated via a far lateral suboccipital approach. DESIGN: Retrospectively clinic case investigation. SETTING: Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. PARTICIPANTS: Between January 1997 and June 2003, 10 patients were treated surgically with VFMMs in Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. In the series of 10 patients, ages ranged from 37 to 72 years, mean (53±10) years, were consisted of 6 males and 4 females. All the subjects were informed of the treatment plan and agreed to join the experiment. Early symptoms included headache and upper cervical pain. The time between the first occurrence of symptoms and the diagnosis ranged from 6 months to 17 months, mean (10.3±3.4) months. Main presenting symptoms were unilateral upper extremity sensory and motor deficits in 6 cases, swallowing difficulties in 2 and spastic quadriparesis in 2. VFMMs were demonstrated as round by the computed tomographic (CT) scan and magnetic resonance imaging (MRI) in all patients. The maximum diameter of tumors ranged from 2 to 4 cm, mean (2.55±0.57) cm, including 2 cm in one case, 2.0-3.0 cm in six and 3.0-4.0 cm in three. METHODS: ①All tumors were removed via the far lateral suboccipital approach. Resection of the posterior 5 mm of the condyle was necessary in one patient whose tumors' diameter were 2 cm. The patient was situated in the lateral decubitus position. The head was fixed in a Mayfield headrest. A C-shaped incision made behind the ear 2 cm medial to the mastoid process, turning vertically down to the level C4, to expose the extradural segment of the vertebral artery (VA). After the dura was opened longitudinally behind VA entry point, the tumor was revealed to identify the complete cranial nerves and the intracranial VA under magnification of the surgical microscope. Every attempt should be made to keep the arachnoid and the dentate ligament was sectioned. Then the tumor was debulked significantly, and dissected away from the cranial nerves and the blood vessels with microsurgical techniques. If it was risk to dissect tumor from the vertebral artery, its branches, or any cranial nerve, the progression was discontinued and portion of the tumor was left behind. After resection of the tumor, the site of its attachment was coagulated and the involved layer of dura was resected. ②The degree of tumor resection was classified based on Al-Mefty's grade into three categories: gross-total resection: excision of the dural attachment and drilling of adjacent bone; near-total resection: a few millimeters of insulated and cauterized tumor were left on the vertebral artery or other vital; subtotal resection: more than 50% of the tumor mass were removed. ③All patients underwent clinical examination for lower cranial nerves or long tract deficits on the first day postoperatively. CT or MRI and neurological examinations were performed at 3 months of follow-up. MAIN OUTCOME MEASURES: Operative effect. RESULTS: All ten patients with VFMMs were treated via a far lateral suboccipital approach. Gross total resection was achieved in 6 patients, near-total resection was carried out in 2 and subtotal resection in 2 patients. One patients died in the postoperative period due to acute respiratory distress syndrome, five patients kept normal neurological status, whereas other four patients suffered from lower cranial nerve deficits and aspiration pneumonia was observed in two of them. The data of following up for 3 months showed that 2 patients still had lower cranial nerve deficit and others recovered from their illness. No tumor relapse or increment was found in CT or MRI scans. CONCLUSION: Most of VFMMs could be totally removed via a far lateral suboccipital approach with or without resection of the occipital condyle according to the tumor size, allowing most of these patients to achieve a good outcome in a 3 months follow-up.展开更多
Objective To investigate the exposed areas in brainstem in brainstem ventral region via the suboccipital far lateral transcondylar approach. Methods Ten (20 sides) adult cadaveric specimens which perfused with colored...Objective To investigate the exposed areas in brainstem in brainstem ventral region via the suboccipital far lateral transcondylar approach. Methods Ten (20 sides) adult cadaveric specimens which perfused with colored silicone were studied. Stepwise dissections via the suboccipital far-lateral展开更多
Objective:to compare the methods of petrous apical bone removal and to explore the applicable scope of Kawase approach and retrosigmoid sinus-internal auditory canal approach.Methods:one group of cadaveric head specim...Objective:to compare the methods of petrous apical bone removal and to explore the applicable scope of Kawase approach and retrosigmoid sinus-internal auditory canal approach.Methods:one group of cadaveric head specimens simulated Kawase approach to measure the data of“Kawase triangle”,the other group simulated retrosigmoid sinus-internal auditory canal approach to measure the safety range of the grinding bone window.Then we explored the clinical indications of the two surgical approaches.Result:the grinding depth of Kawase triangle was 11.6±0.14 mm,and the range of clival exposed after grinding Kawase triangle was 22.4±1.22 mm,which could effectively expose the ventrolateral brainstem,the midline of clivus and the area above the facial acoustic nerve.The diameter of the anterior and posterior of the grinding bone window in the retrosigmoid sinus-internal auditory canal approach was 21.95±2.23 mm.In front of the exposure area were the internal carotid artery,the cavernous sinus,and the upper trigeminal nerve;the lower part was the connection between the facial acoustic nerve and the abducent nerve.Conclusion:Kawase approach is suitable for lesions of ventrolateral brainstem,middle superior clivus,with or without invasion of middle cranial fossa;the retrosigmoid sinus-superior internal auditory canal approach is suitable for lesions mainly in cerebellopontine angle area and only slightly invading Meckel’s cavity.展开更多
Background Vestibular schwannoma, the commonest form of intracranial schwannoma, arises from the Schwann cells investing the vestibular nerve. At present, the surgery for vestibular schwannoma remains one of the most ...Background Vestibular schwannoma, the commonest form of intracranial schwannoma, arises from the Schwann cells investing the vestibular nerve. At present, the surgery for vestibular schwannoma remains one of the most complicated operations demanding for surgical skills in neurosurgery. And the trend of minimal invasion should also be the major influence on the management of patients with vestibular schwannomas. We summarized the microsurgical removal experience in a recent series of vestibular schwannomas and presented the operative technique and cranial nerve preservation in order to improve the rates of total tumor removal and facial nerve preservation. Methods A retrospective analysis was performed in 145 patients over a 7-year period who suffered from vestibular schwannomas that had been microsurgically removed by suboccipital retrosigmoid transmeatus approach with small craniotomy. CT thinner scans revealed the tumor size in the internal auditory meatus and the relationship of the posterior wall of the internal acoustic meatus to the bone labyrinths preoperatively. Brain stem evoked potential was monitored intraoperatively. The posterior wall of the internal acoustic meatus was designedly drilled off. Patient records and operative reports, including data from the^electrophysiological monitoring, follow-up audiometric examinations, and neuroradiological findings were analyzed. Results Total tumor resection was achieved in 140 cases （96.6%） and subtotal resection in 5 cases. The anatomical integrity of the facial nerve was preserved in 91.0% （132/145） of the cases. Intracranial end-to-end anastomosis of the facial nerve was performed in 7 cases. Functional preservation of the facial nerve was achieved in 115 patients （Grade ! and Grade ]I, 79.3%）. No patient died in this series. Preservation of nerves and vessels were as important as tumor removal during the operation. CT thinner scan could show the relationship between the posterior wall of the internal acoustic meatus and bone labyrinths, that is helpful for a safe drilling of the posterior wall of the internal acoustic meatus. Conclusions The goal of every surgery should be the preservation of function of all cranial nerves. Using the retrosigmoid approach with small craniotomy is possible even for large schwannomas. Knowing the microanatomy of the cerebellopontine angle and internal auditory meatus, intraoperating neurophysiological monitoring of the facial nerve function, and the microsurgical techniques of the surgeons are all important factors for improving total tumor removal and preserving facial nerve function.展开更多
Background:When utilizing the retrosigmoid approach(RA),accurately identifying the transverse and sigmoid sinus transition(TSST)is a key procedure for neurosurgeons,especially in developing countries restricted by the...Background:When utilizing the retrosigmoid approach(RA),accurately identifying the transverse and sigmoid sinus transition(TSST)is a key procedure for neurosurgeons,especially in developing countries restricted by the lack of expensive devices,such as the neural navigation system and the three-dimensional volumetric image-rendered system.Before operations,a computed tomography scan is a common and cost-effective method of checking patients who suffer lesions located at the cerebellopontine angle.Therefore,we present a technique using only high-resolution computed tomography to identify the transverse and sigmoid sinus transition.Methods:This retrospective study included 35 patients who underwent retrosigmoid approach operations to resect an acoustic neurinoma with the assistance of our technique.In brief,our technique contains 4 steps:(1)All patients’1-mm,consecutive,high-resolution computed tomographic images that clearly displayed landmarks,such as the inion,lambdoid suture,occipitomastoid suture,and the mastoid emissary foramen,were investigated initially.(2)We selected two particular slices(A and B)among all of these high-resolution computed tomographic images in which scanning planes were parallel with the line drawn from the root of the zygoma to the inion(LZI).Slice A contained both the root of the zygoma and the inion simultaneously,and slice B displayed the mastoid emissary foramen.(3)Four points(α,β,γ,δ)were arranged on slices A and B,and pointαwas located at the inner surface of the skull,which represents the posterior part of the sulci of the sigmoid sinus.Pointβwas located at the outer surface of the skull,and the line connecting them was perpendicular to the bone.Similarly,on slice B,we labeled pointγas the point that represents the posterior part of the sulci of the sigmoid sinus at the inner surface and pointδas the point located at the outer surface of the skull,and the line connecting them was also perpendicular to the bone.The distances between pointβand the lambdoid suture/occipitomastoid suture and between pointδand the mastoid emissary foramen were calculated for slices A and B,respectively.(4)During the operation,a line indicating the LZI was drawn on the bone with ink when the superficial soft tissue was pushed away,and this line would cross the lambdoid suture/occipitomastoid suture.With both the crosspoint and the distance obtained from the high-resolution CT images,we could locate pointβ.We also used the same method to locate pointδafter revealing the mastoid emissary foramen.The line connecting pointβand pointδindicated the posterior border of the sigmoid sinus,and the intersection between the line and LZI indicated the inferior knee of the transverse and sigmoid sinus transition(TSST).Results:All 35 patients underwent the RA craniectomies that were safely assisted by our technique,and neither the sigmoid sinus nor the transverse sinus was lacerated during the operations.Conclusion:Our cost-effective technique is reliable and convenient for identifying the transverse and sigmoid sinus transition(TSST)which could be widely performed to guarantee the safety of RA craniectomy.展开更多
Background In China, the feasibility of keyhole approach in surgical treatment of petroclival meningioma has not been well evaluated. This report summarized our experience in 25 patients with petroclival meningioma wh...Background In China, the feasibility of keyhole approach in surgical treatment of petroclival meningioma has not been well evaluated. This report summarized our experience in 25 patients with petroclival meningioma who had been treated with keyhole approach surgery. Methods From July 2000 to July 2005, 25 patients with petroclival meningioma were subjected to resection via subtemporal, retrosigmoid or combined keyhole approaches. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. Results The maximum diameter of tumors ranged from 2 to 7 cm （mean, 4.5 cm）. Gross total resection （GTR） was achieved in 14 patients, giving a GTR rate of 56%. Subtotal resection （STR） was carried out in 8 patients and partial resection in 3. Thirteen patients kept normal neurological status, whereas others suffered from cranial nerve deficits （Ⅶ, Ⅶ, Ⅲ and lower CN）. One patient died in the postoperative period. Conclusions Keyhole approach surgery, especially the combined keyhole approach is suitable for the treatment of petroclival meningioma. It provides easy and quick access to the supra- and infratentorial juxta-clival region without drilling of the petrous bone. Complications related to the approach can be minimized.展开更多
文摘BACKGROUND: In recent years some reports have been published propagating microsurgical resection of ventral foramen magnum meningiomas (VFMMs). Operative approaches to these lesions have been studied by various authors, but remain controversial. OBJECTIVE: To discuss the operative technique and outcome in patients with VFMMs who had been treated via a far lateral suboccipital approach. DESIGN: Retrospectively clinic case investigation. SETTING: Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. PARTICIPANTS: Between January 1997 and June 2003, 10 patients were treated surgically with VFMMs in Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. In the series of 10 patients, ages ranged from 37 to 72 years, mean (53±10) years, were consisted of 6 males and 4 females. All the subjects were informed of the treatment plan and agreed to join the experiment. Early symptoms included headache and upper cervical pain. The time between the first occurrence of symptoms and the diagnosis ranged from 6 months to 17 months, mean (10.3±3.4) months. Main presenting symptoms were unilateral upper extremity sensory and motor deficits in 6 cases, swallowing difficulties in 2 and spastic quadriparesis in 2. VFMMs were demonstrated as round by the computed tomographic (CT) scan and magnetic resonance imaging (MRI) in all patients. The maximum diameter of tumors ranged from 2 to 4 cm, mean (2.55±0.57) cm, including 2 cm in one case, 2.0-3.0 cm in six and 3.0-4.0 cm in three. METHODS: ①All tumors were removed via the far lateral suboccipital approach. Resection of the posterior 5 mm of the condyle was necessary in one patient whose tumors' diameter were 2 cm. The patient was situated in the lateral decubitus position. The head was fixed in a Mayfield headrest. A C-shaped incision made behind the ear 2 cm medial to the mastoid process, turning vertically down to the level C4, to expose the extradural segment of the vertebral artery (VA). After the dura was opened longitudinally behind VA entry point, the tumor was revealed to identify the complete cranial nerves and the intracranial VA under magnification of the surgical microscope. Every attempt should be made to keep the arachnoid and the dentate ligament was sectioned. Then the tumor was debulked significantly, and dissected away from the cranial nerves and the blood vessels with microsurgical techniques. If it was risk to dissect tumor from the vertebral artery, its branches, or any cranial nerve, the progression was discontinued and portion of the tumor was left behind. After resection of the tumor, the site of its attachment was coagulated and the involved layer of dura was resected. ②The degree of tumor resection was classified based on Al-Mefty's grade into three categories: gross-total resection: excision of the dural attachment and drilling of adjacent bone; near-total resection: a few millimeters of insulated and cauterized tumor were left on the vertebral artery or other vital; subtotal resection: more than 50% of the tumor mass were removed. ③All patients underwent clinical examination for lower cranial nerves or long tract deficits on the first day postoperatively. CT or MRI and neurological examinations were performed at 3 months of follow-up. MAIN OUTCOME MEASURES: Operative effect. RESULTS: All ten patients with VFMMs were treated via a far lateral suboccipital approach. Gross total resection was achieved in 6 patients, near-total resection was carried out in 2 and subtotal resection in 2 patients. One patients died in the postoperative period due to acute respiratory distress syndrome, five patients kept normal neurological status, whereas other four patients suffered from lower cranial nerve deficits and aspiration pneumonia was observed in two of them. The data of following up for 3 months showed that 2 patients still had lower cranial nerve deficit and others recovered from their illness. No tumor relapse or increment was found in CT or MRI scans. CONCLUSION: Most of VFMMs could be totally removed via a far lateral suboccipital approach with or without resection of the occipital condyle according to the tumor size, allowing most of these patients to achieve a good outcome in a 3 months follow-up.
文摘Objective To investigate the exposed areas in brainstem in brainstem ventral region via the suboccipital far lateral transcondylar approach. Methods Ten (20 sides) adult cadaveric specimens which perfused with colored silicone were studied. Stepwise dissections via the suboccipital far-lateral
文摘Objective:to compare the methods of petrous apical bone removal and to explore the applicable scope of Kawase approach and retrosigmoid sinus-internal auditory canal approach.Methods:one group of cadaveric head specimens simulated Kawase approach to measure the data of“Kawase triangle”,the other group simulated retrosigmoid sinus-internal auditory canal approach to measure the safety range of the grinding bone window.Then we explored the clinical indications of the two surgical approaches.Result:the grinding depth of Kawase triangle was 11.6±0.14 mm,and the range of clival exposed after grinding Kawase triangle was 22.4±1.22 mm,which could effectively expose the ventrolateral brainstem,the midline of clivus and the area above the facial acoustic nerve.The diameter of the anterior and posterior of the grinding bone window in the retrosigmoid sinus-internal auditory canal approach was 21.95±2.23 mm.In front of the exposure area were the internal carotid artery,the cavernous sinus,and the upper trigeminal nerve;the lower part was the connection between the facial acoustic nerve and the abducent nerve.Conclusion:Kawase approach is suitable for lesions of ventrolateral brainstem,middle superior clivus,with or without invasion of middle cranial fossa;the retrosigmoid sinus-superior internal auditory canal approach is suitable for lesions mainly in cerebellopontine angle area and only slightly invading Meckel’s cavity.
文摘Background Vestibular schwannoma, the commonest form of intracranial schwannoma, arises from the Schwann cells investing the vestibular nerve. At present, the surgery for vestibular schwannoma remains one of the most complicated operations demanding for surgical skills in neurosurgery. And the trend of minimal invasion should also be the major influence on the management of patients with vestibular schwannomas. We summarized the microsurgical removal experience in a recent series of vestibular schwannomas and presented the operative technique and cranial nerve preservation in order to improve the rates of total tumor removal and facial nerve preservation. Methods A retrospective analysis was performed in 145 patients over a 7-year period who suffered from vestibular schwannomas that had been microsurgically removed by suboccipital retrosigmoid transmeatus approach with small craniotomy. CT thinner scans revealed the tumor size in the internal auditory meatus and the relationship of the posterior wall of the internal acoustic meatus to the bone labyrinths preoperatively. Brain stem evoked potential was monitored intraoperatively. The posterior wall of the internal acoustic meatus was designedly drilled off. Patient records and operative reports, including data from the^electrophysiological monitoring, follow-up audiometric examinations, and neuroradiological findings were analyzed. Results Total tumor resection was achieved in 140 cases （96.6%） and subtotal resection in 5 cases. The anatomical integrity of the facial nerve was preserved in 91.0% （132/145） of the cases. Intracranial end-to-end anastomosis of the facial nerve was performed in 7 cases. Functional preservation of the facial nerve was achieved in 115 patients （Grade ! and Grade ]I, 79.3%）. No patient died in this series. Preservation of nerves and vessels were as important as tumor removal during the operation. CT thinner scan could show the relationship between the posterior wall of the internal acoustic meatus and bone labyrinths, that is helpful for a safe drilling of the posterior wall of the internal acoustic meatus. Conclusions The goal of every surgery should be the preservation of function of all cranial nerves. Using the retrosigmoid approach with small craniotomy is possible even for large schwannomas. Knowing the microanatomy of the cerebellopontine angle and internal auditory meatus, intraoperating neurophysiological monitoring of the facial nerve function, and the microsurgical techniques of the surgeons are all important factors for improving total tumor removal and preserving facial nerve function.
文摘Background:When utilizing the retrosigmoid approach(RA),accurately identifying the transverse and sigmoid sinus transition(TSST)is a key procedure for neurosurgeons,especially in developing countries restricted by the lack of expensive devices,such as the neural navigation system and the three-dimensional volumetric image-rendered system.Before operations,a computed tomography scan is a common and cost-effective method of checking patients who suffer lesions located at the cerebellopontine angle.Therefore,we present a technique using only high-resolution computed tomography to identify the transverse and sigmoid sinus transition.Methods:This retrospective study included 35 patients who underwent retrosigmoid approach operations to resect an acoustic neurinoma with the assistance of our technique.In brief,our technique contains 4 steps:(1)All patients’1-mm,consecutive,high-resolution computed tomographic images that clearly displayed landmarks,such as the inion,lambdoid suture,occipitomastoid suture,and the mastoid emissary foramen,were investigated initially.(2)We selected two particular slices(A and B)among all of these high-resolution computed tomographic images in which scanning planes were parallel with the line drawn from the root of the zygoma to the inion(LZI).Slice A contained both the root of the zygoma and the inion simultaneously,and slice B displayed the mastoid emissary foramen.(3)Four points(α,β,γ,δ)were arranged on slices A and B,and pointαwas located at the inner surface of the skull,which represents the posterior part of the sulci of the sigmoid sinus.Pointβwas located at the outer surface of the skull,and the line connecting them was perpendicular to the bone.Similarly,on slice B,we labeled pointγas the point that represents the posterior part of the sulci of the sigmoid sinus at the inner surface and pointδas the point located at the outer surface of the skull,and the line connecting them was also perpendicular to the bone.The distances between pointβand the lambdoid suture/occipitomastoid suture and between pointδand the mastoid emissary foramen were calculated for slices A and B,respectively.(4)During the operation,a line indicating the LZI was drawn on the bone with ink when the superficial soft tissue was pushed away,and this line would cross the lambdoid suture/occipitomastoid suture.With both the crosspoint and the distance obtained from the high-resolution CT images,we could locate pointβ.We also used the same method to locate pointδafter revealing the mastoid emissary foramen.The line connecting pointβand pointδindicated the posterior border of the sigmoid sinus,and the intersection between the line and LZI indicated the inferior knee of the transverse and sigmoid sinus transition(TSST).Results:All 35 patients underwent the RA craniectomies that were safely assisted by our technique,and neither the sigmoid sinus nor the transverse sinus was lacerated during the operations.Conclusion:Our cost-effective technique is reliable and convenient for identifying the transverse and sigmoid sinus transition(TSST)which could be widely performed to guarantee the safety of RA craniectomy.
文摘Background In China, the feasibility of keyhole approach in surgical treatment of petroclival meningioma has not been well evaluated. This report summarized our experience in 25 patients with petroclival meningioma who had been treated with keyhole approach surgery. Methods From July 2000 to July 2005, 25 patients with petroclival meningioma were subjected to resection via subtemporal, retrosigmoid or combined keyhole approaches. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. Results The maximum diameter of tumors ranged from 2 to 7 cm （mean, 4.5 cm）. Gross total resection （GTR） was achieved in 14 patients, giving a GTR rate of 56%. Subtotal resection （STR） was carried out in 8 patients and partial resection in 3. Thirteen patients kept normal neurological status, whereas others suffered from cranial nerve deficits （Ⅶ, Ⅶ, Ⅲ and lower CN）. One patient died in the postoperative period. Conclusions Keyhole approach surgery, especially the combined keyhole approach is suitable for the treatment of petroclival meningioma. It provides easy and quick access to the supra- and infratentorial juxta-clival region without drilling of the petrous bone. Complications related to the approach can be minimized.
