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
Background Image-guided neurosurgery, endoscopic-assisted neurosurgery and the keyhole approach are three important parts of minimally invasive neurosurgery and have played a significant role in treating skull base le...Background Image-guided neurosurgery, endoscopic-assisted neurosurgery and the keyhole approach are three important parts of minimally invasive neurosurgery and have played a significant role in treating skull base lesions. This study aimed to investigate the potential usefulness of coupling of the endoscope with the far lateral keyhole approach and image guidance at the ventral craniocervical junction in a cadaver model. Methods We simulated far lateral keyhole approach bilaterally in five cadaveric head specimens （10 cranial hemispheres）. Computed tomography-based image guidance was used for intraoperative navigation and for quantitative measurements. Skull base structures were observed using both an operating microscope and a rigid endoscope. The jugular tubercle and one-third of the occipital condyle were then drilled, and all specimens were observed under the microscope again. We measured and compared the exposure of the petroclivus area provided by the endoscope and by the operating microscope. Statistical analysis was performed by analysis of variance followed by the Student-Newman-Keuls test. Results With endoscope assistance and image guidance, it was possible to observe the deep ventral craniocervical junction structures through three nerve gaps （among facial-acoustical nerves and the lower cranial nerves） and structures normally obstructed by the jugular tubercle and occipital condyle in the far lateral keyhole approach. The surgical area exposed in the petroclival region was significantly improved using the 0° endoscope （1147.80 mm2） compared with the operating microscope （（756.28±50.73） mm2）. The far lateral retrocondylar keyhole approach, using both 0° and 30° endoscopes, provided an exposure area （（1147.80±159.57） mm2 and （1409.94±155.18） mm2, respectively） greater than that of the far lateral transcondylar transtubercular keyhole approach （（1066.26±165.06） mm2） （P 〈0.05）. Conclusions With the aid of the endoscope and image guidance, it is possible to approach the ventral craniocervical junction with the far lateral keyhole approach. The use of an angled-lens endoscope can significantly improve the exposure of the petroclival region without drilling the jugular tubercle and occipital condyle.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Background Image-guided neurosurgery, endoscopic-assisted neurosurgery and the keyhole approach are three important parts of minimally invasive neurosurgery and have played a significant role in treating skull base lesions. This study aimed to investigate the potential usefulness of coupling of the endoscope with the far lateral keyhole approach and image guidance at the ventral craniocervical junction in a cadaver model. Methods We simulated far lateral keyhole approach bilaterally in five cadaveric head specimens （10 cranial hemispheres）. Computed tomography-based image guidance was used for intraoperative navigation and for quantitative measurements. Skull base structures were observed using both an operating microscope and a rigid endoscope. The jugular tubercle and one-third of the occipital condyle were then drilled, and all specimens were observed under the microscope again. We measured and compared the exposure of the petroclivus area provided by the endoscope and by the operating microscope. Statistical analysis was performed by analysis of variance followed by the Student-Newman-Keuls test. Results With endoscope assistance and image guidance, it was possible to observe the deep ventral craniocervical junction structures through three nerve gaps （among facial-acoustical nerves and the lower cranial nerves） and structures normally obstructed by the jugular tubercle and occipital condyle in the far lateral keyhole approach. The surgical area exposed in the petroclival region was significantly improved using the 0° endoscope （1147.80 mm2） compared with the operating microscope （（756.28±50.73） mm2）. The far lateral retrocondylar keyhole approach, using both 0° and 30° endoscopes, provided an exposure area （（1147.80±159.57） mm2 and （1409.94±155.18） mm2, respectively） greater than that of the far lateral transcondylar transtubercular keyhole approach （（1066.26±165.06） mm2） （P 〈0.05）. Conclusions With the aid of the endoscope and image guidance, it is possible to approach the ventral craniocervical junction with the far lateral keyhole approach. The use of an angled-lens endoscope can significantly improve the exposure of the petroclival region without drilling the jugular tubercle and occipital condyle.
