Yoshichika Kubo

Anterior cervical vertebrectomy and interbody fusion for multi-level spondylosis and ossification of the posterior longitudinal ligament

Multi-level cervical spondylosis and ossification of the posterior longitudinal ligament (OPLL) are well-documented causes of myelopathy. The choice of surgical procedures remain controversial. Between January 1983 and December 1987, we have performed anterior cervical vertebrectomy in 45 patients with cervical myelopathy caused by multi-level spondylosis and OPLL. They consisted of 19 patients with cervical spondylosis, 12 with OPLL, and 14 with combined lesions of both cervical spondylosis and OPLL. There were 32 men and 13 women. The mean age was 55 years, ranging from 35 to 70 years. In all of our 45 patients, anterior vertebrectomy, discectomy, removal of posterior osteophytes and OPLL, and interbody fusion were done for progressive myelopathy refractory to conservative treatment. In 2 of 45 patients, 5 vertebral bodies were resected; in 3 patients, 4 vertebral bodies were resected; in 12 patients, 3 vertebral bodies were resected, in 19 patients, 2 vertebral bodies were resected; and in 9 patients, 1 vertebral body was resected. Thirty-nine of 45 patients (87%) had good results. Neurological signs did not improve in 5 patients (11%). One patient died because of agranulocytosis secondary to treatment with antibiotics. In conclusion, cervical cord compression caused by lesions located principally in the anterior aspect of the spinal canal may be completely relieved via anterior vertebrectomy, discectomy, removal of the calcified ligament, and fusion.

Microsurgical anatomy of the lower cervical spine and cord.

The authors dissected the cervical spine and its surrounding structures from 40 adult cadavers under a surgical microscope. The anterior part of the spine and spinal cord was examined after vertebrectomy. The posterior longitudinal ligament (PLL) consists of two layers; the anterior one is termed the deep layer, and the posterior one is termed the superficial layer. These two layers adhered together loosely. In the lateral portion of the spinal canal, the superficial layer joined the periradicular sheath at the level of the intervertebral disc spaces and joined the dura mater at the level of the vertebral bodies. After the removal of the deep layer, the anterior internal vertebral venous plexus was seen on top of the lateral part of the superficial layer. The venous plexus was embedded between the double-layered PLLs, was not located in the epidural space, and was not seen in the medial part of the PLL. The PLL without venous channels on top of it was about 10 mm in width at the levels of the intervertebral disc and about 5 mm at the levels of the vertebral body. The anterior root exit zone (AREZ) was an elliptical shape; the transverse length of the AREZ was about 2 mm, and the longitudinal length was 10 to 15 mm. The average number of anterior rootlets on the AREZ was 17 to 25 and tended to decrease in the lower cervical spinal cord. The posterior structures were examined after en bloc laminectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-traumatic dissecting aneurysms of the intracranial vertebral artery: report of six cases

SummaryWe present 6 cases with dissecting aneurysm of the intracranial vertebral artery who developed subarachnoid haemorrhage (SAH). The following procedures were performed in this series; trapping of the involved artery in 2, proximal occlusion of the vertebral artery with detachable balloon in 2, and proximal clipping of the vertebral artery in 2. Proximal occlusion of the vertebral artery in 4 and trapping of the vertebral artery in one gave excellent results. We believe the treatment of choice is proximal occlusion of the vertebral artery, either by open surgery or by interventional neuroradiological procedures.

Endothelium-dependent relaxation of human basilar arteries.

We studied the effects of acetylcholine and calcium ionophore A23187 on human basilar artery rings. Among 11 arteries, both agents produced significant relaxations in five, A23187 but not acetylcholine caused a response in six, and neither agent was effective in four. After rubbing off the endothelium, the relaxations induced by both agents were significantly attenuated. Indomethacin (a cyclooxygenase inhibitor) and AA861 (a specific inhibitor of 5-lipoxygenase) did not but SKF525A (an inhibitor of cytochrome P450-dependent monooxygenase) did significantly inhibit the acetylcholine-induced relaxation in human basilar arteries. On the other hand, AA861 inhibited while neither indomethacin nor SKF525A had any effect on the A23187-induced relaxation. Our results suggest that different mechanisms may be involved in acetylcholine and A23187-induced relaxations in human basilar arteries.

Thoracic spinal angiomyolipoma with extracanal extension to the thoracic cavity : A case report

Study Design. Case report and review of the literature. Objective. To describe a 72‐year‐old man with thoracic spinal angiomyolipoma in the ventral aspect of the epidural space and extracanal extension to the posterior mediastinum, to discuss the clinical and radiologic features and unique biologic behavior of this entity, and to review of the literature on angiolipoma and angiomyolipoma. Summary of Background Data. Spinal angiolipoma and angiomyolipoma are rare tumors, which are localized almost exclusively in the dorsal epidural space of the thoracic spine. Most reported cases have no tendency to involve the surrounding tissue. Methods. The authors describe the radiologic, surgical, and pathologic findings of this patient and review the findings from other reported cases. Results. Anterior decompression was performed using a right transthoracic incision, and the neurologic symptoms improved immediately. There were no signs of recurrence of the tumor or neurologic deficit within a 2‐year follow‐up period. Conclusion. Results of a literature survey of these tumors support management by prompt and radical surgical intervention for long‐term cure, even in cases in which the infiltrating nature is recognized.

Surgical treatment of ossification of the posterior longitudinal ligament in the thoracic spine

Thoracic ossification of the posterior longitudinal ligament (OPLL) is a rare entity causing thoracic myelopathy. Its surgical decompression is still challenging. Three patients admitted with progressive myelopathy due to thoracic OPLL are described. A transthoracic anterolateral approach was used in the first and second cases, in which OPLL was located at the T3-T4 and T5-T6 and at the T7-T8 levels, respectively. In the third case, a transsternal approach was adopted for OPLL at the T1-T2 level. The OPLL, including dural ossification, was removed by microsurgical techniques as extensively as possible. Myelopathy in all three cases became relieved or stable postoperatively. Operative procedures are described in detail. From the viewpoint of surgical anatomy, the selection of operative approach depends on the level of the OPLL. The authors emphasize that a transthoracic anterolateral approach is the treatment of choice for extensive anterior pathology such as OPLL involving more than two thoracic bodies below the T4. A transsternal approach can provide excellent access to a lesion at the upper three thoracic bodies.

Transfrontal intradural microsurgical decompression for traumatic optic nerve injury

SummaryMicrosurgical decompression of the optic nerve was performed in 22 patients with traumatic optic nerve injury through a transfrontal intradural approach. When significant improvement is defined as an improvement of the visual acuity of 0.1 or more, 11 patients (50%) showed significant improvement and 7 patients (32%) showed nonsignificant improvement. Four patients who had been blind preoperatively, did not show any improvement.In cases with a preoperative visual acuity of 0.01 or more, significant improvement was obtained in 80% of the patients, and when the preoperative visual acuity was not nill but less than 0.01, 38% of patients showed significant improvement.We conclude that a transfrontal intradural microsurgical decompression is indicated, when the preoperative visual acuity is 0.01 or more and the time lag is less than 14 days after the injury.

Spinal dural arteriovenous malformation: report of an unusual case.

We present an unusual case of a spinal dural arteriovenous malformation (AVM) which produced compression radiculopathy of the left S1 nerve root. The nerve root was compressed by epidural vessels, draining vessels, and the nidus, without the characteristic myelographic findings of a dural AVM. No feeding vessels could be identified. It is important to consider the possibility of a spinal dural AVM in middle-aged patients who suffer lumbosacral radiculopathy, even if myelography does not demonstrate the characteristic findings.

Successful removal of air gun bullets from the third ventricle.

A patient with air gun bullets in the 3rd ventricle associated with delayed ventricular hemorrhage is presented. Through an anterior transcallosal approach, the surgeon successfully removed the bullets without any significant permanent sequelae.