Masahiro Ogino

Successful removal of solitary intramedullary spinal cord metastasis from colon cancer

A 69-year-old patient with an intramedullary metastasis from colon carcinoma is presented. Total removal of the tumor brought him 3 months of useful life. Although radiation therapy is generally favored, one should consider microsurgical resection of discrete, solitary intramedullary metastases in patients with radioresistant primary tumors.

Altered Blood Flow Distribution in the Rat Spinal Cord under Chronic Compression

Study Design. Sham-operation–controlled animal study to assess alterations in blood flow in the spinal cord in a chronic compression model. Laboratory investigation. Objective. Cervical myelopathy is a common cause of disability in elderly patients. Hypothesis was made that ischemia subsequent to the spinal cord compression plays an important role in the pathogenesis of the spinal cord dysfunction. This study was undertaken to assess alterations in the blood flow of the spinal cord under chronic compression in a rat model. Summary of Background Data. Histologic study of spinal cord from patients with spondylotic myelopathy showed ischemic tissue changes. Experimentally, spinal cord hypoperfusion in combination with chronic spinal cord compression induced myelopathy in dogs. We previously showed that chronic compression of the spinal cord in rats produces gradual deterioration of mobility of the animals accompanied by cord tissue degeneration compatible with ischemic changes. Methods. Chronic compression of the cervical spinal cord was implemented by implantation of a thin urethane polymer sheet under the C5–C6 laminae, which expands by absorbing tissue water over 48–72 hours. The control group underwent sham operation. Twelve weeks later, blood flow to the C3–C4 and C5–C6 spinal cord segments were measured by fluorescent microsphere methods. Results. In the control group, the blood flow in the C5–C6 segment was larger than C3–C4 segment. In the compression group, the blood flow in the C5–C6 was significantly reduced compared to the C3–C4 segment. Conclusion. Under chronic focal spinal cord compression, there was a decrease of the blood flow in the compressed segment in comparison to the rostral segment. Our data are compatible with the hypothesis that alteration in the spinal cord blood flow contributes to pathogenesis of myelopathy.

Proper management of the rotational vertebral artery occlusion secondary to spondylosis

A 66-year-old man with cervical spondylosis noticed severe vertigo when turning his head to the right. He underwent subclavian arteriography elsewhere, which showed a block of the contrast medium in the right vertebral artery (VA) at the C5/6 level when the patient turned his head to the right. After referral to our institute, however, postcontrast CT scan revealed an attenuated shadow of the venous plexus around the right VA at the C3/4 level. Repeated selective angiography with rotation of the head after visualization of the entire VA verified the level of obstruction to be at C3/4. Resection of the C4 transverse process through an anterior approach with drilling of the C3/4 spondylotic spur of the uncinate processi completely resolved the arterial impingement and the symptom. When evaluating rotational VA occlusion, dynamic angiography with selective catheterization is essential in determining which level is affected. The postcontrast CT scan is also useful because it suggests the level even without head rotation.

Comparison of numerical change of epidermal growth factor receptor gene among pre- and postradiation glioma, and gliosis, and its clinical use

Surgery with following chemoradiotherapy is the mainstream glioma treatment. In the course of postradiation events, however, it is sometimes difficult for neurosurgeons, radiologists, and pathologists to discriminate tumor recurrence from radiation necrosis. The epidermal growth factor receptor (EGFR) gene, on chromosome 7, is known to gain in copy number frequently in high-grade gliomas. The authors applied the fluorescence in situ hybridization (FISH) method to observe the genes numerical status in pre- and postradiation glioma samples to elucidate whether this technique is useful in the discrimination of glioma recurrence from radiation necrosis. When 15 postradiation glioma samples and 4 postradiation nonglioma samples were tested, all the recurrent glioma tissue harbored numerical aberrations of the gene, whereas no abnormality could be observed in necrosis or in nonglioma gliosis. FISH could even prove a residual glioma cell in a gliotic tissue taken by needle biopsy after gamma-knife radiosurgery, which had been executed on a supposed metastatic brain tumor. FISH is considered to be of help in accurate diagnosis, especially when the usual histopathological diagnosis is difficult because of radiation effects or small sample size.

Is Postoperative CT Scanning Predictive of Subdural Electrode Placement Complications in Pediatric Epileptic Patients

Aims: To understand the reliability of postoperative CT scans to predict the development of intracranial hemorrhagic complications associated with subdural electrode implants for monitoring intractable seizure, we reviewed the data of a consecutive series of children treated at our institution. Methods: Forty children (mean age: 11.4 years) with subdural electrode implants were reviewed. The immediate postoperative CT scans were evaluated for the presence of hemorrhagic complications and/or brain swelling resulting in a midline shift. Results: Twenty-six patients (65%) presented a postoperative midline shift (range = 2–10 mm; mean shift = 4.0 mm). Two children had a midline shift of >5 mm. Two patients with a shift of <5 mm at the first CT scan required a repeat craniotomy. These patients experienced worsening neurologic symptoms in a delayed fashion on postoperative days 1 and 4, respectively. This was correlated to an increase in midline shift of >5 mm. Conclusions: Subdural electrode implants in children are safe. The presence of a midline shift of <5 mm is common postoperatively. The presence and extension of the midline shift at the first CT scan does not seem to be predictive of the development of symptomatic complications with a mass effect. Complications happened in a delayed fashion.

Axilloaxillary bypass for the treatment of subclavian artery stenosis complicated by bilateral common carotid artery occlusion: technical case report.

OBJECTIVE AND IMPORTANCEWe successfully treated a patient with stenosis of the left subclavian artery, complicated by bilateral common carotid artery occlusion, via axilloaxillary bypass surgery. CLINICAL PRESENTATIONA 67-year-old patient with a history of hypertension and cerebral infarction underwent neck irradiation for treatment of a vocal cord tumor. Three months later, he began to experience transient tetraparesis several times per day. The blood pressure measurements for his right and left arms were different. Supratentorial blood flow was markedly low. The common carotid arteries were bilaterally occluded, and the right vertebral artery was hypoplastic. Therefore, only the left vertebral artery contributed to the patient’s cerebral circulation; his left subclavian artery was severely stenotic. INTERVENTIONThe patient underwent axilloaxillary bypass surgery because the procedure avoids thoracotomy or sternotomy, manipulation of the carotid artery, and interruption of the vertebral artery blood flow. The patient has been free of symptoms for more than 5 years. CONCLUSIONNeurosurgeons should be aware that extra-anatomic bypass surgery is an effective treatment option for selected patients with cerebral ischemia.

An intraoperative irrigation device using disposable syringes and an extension tube: technical note

BACKGROUND The authors present a simple irrigation device used in a microsurgical setting. METHODS The system consists of a disposable i.v. catheter, an extension tube, a three-way stopcock and two disposable syringes, capable of assembly during a surgical procedure. RESULTS The length of the handpiece of this device is comparable to other microsurgical tools, which allow both the assistant and the surgeon to grab and irrigate in a coordinated fashion. Clots, tumor contents, and tissue debris are effectively washed away. This tool is particularly useful for lavage of subarachnoid clots during surgery for ruptured intracranial aneurysms, allowing precise anatomic orientation. This device is also practical for cooling tissues adjacent to drilling sites. CONCLUSION This system is as efficacious as other available self-irrigating microneurosurgical instruments.