In the 1950's, various techniques for surgical intervention were developed to treat spondylotic cervical diseases and cervical disc herniation. To achieve satisfactory nerve decompression and practical spinal column fixation, a variety of procedures have been introduced, among which an anterior and a posterior apporoach are the two most common operations. Through the history of cervical spine surgery, the introduction of the operating microscope, the progress in radiological diagnosis and the introduction of instrumentation played an important role as breakthroughs. Using a microscope and instrumentation made it possible to perform radical nerve decompression as well as secure and durable fixation. In addition, radiological technology has accelerated clinical recognition and comprehension of the pathophysiology of cervical spondylosis, disc herniation and ossification of the posterior longitudinal ligament (OPLL). On the other hand, instrumentation has also created new problems including surgical complications such as vascular and nerve damage. Surgery for degenerative diseases in the cervical spine is indicated to improve the quality of a patient's life. Therefore, prudent care should be exercised when planning the surgical strategy and when performing operative procedures.

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Recently the number of cervical spondylosis cases seen in outpatient clinics is increasing, as a result of Japan's graying society. There are two major options in surgical treatment : one is anterior decompression and fusion and the other is posterior decompression. The former method can enable us direct decompression of the spinal cord and roots, bring better cervical alignment, and less invasiveness, therefore it can give better results for cervical spondylosis patients. Until now, there were many surgical variations to the anterior approach. However, the Smith-Robinson method is still the gold standard for treatment of cervical disc disease and cervical spondylosis. It is necessary for surgeons to know basic microanatomy around the cervical portion including trachea, major vessels, muscles, and nerves. This paper describes a precise surgical technique for anterior fusion in cervical disc disease.

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Spinal instrumentation has been increasing in popularity in anterior procedures for trauma, deformity or reconstruction of the cervical spinal column following decompression, because it provides solid stability immediately after the operation and facilitates early rehabilitation. Spinal instrumentation has several assets such as avoidance of halo brace or harvesting iliac bone in addition to solid internal stability in most cases. It is important to make the correct decision on surgical indication and selection of the instruments in order to perform spinal instrumentation appropriately. Although spinal instrumentation is a useful surgical option, it is technically demanding and has several drawbacks such as screw back-out, hardware failures, infections or delayed symptomatic adjacent segment degeneration after reconstruction of the anterior column. In this report, we describe our experience of spinal instrumentation for anterior procedures for cervical degenerative disorders and trauma, and discuss the assets and drawbacks of spinal instrumentation.

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Spinal instrumentation using anchor screws and rods is becoming a popular method for posterior cervical fixation as a substitute of previous methods using bone grafts and wiring because it yeilds higher stability and a higher success rate of fusion without sublaminar wiring. There are a variety of cervical anchor screws, such as lateral mass, subaxial transarticular, pedicle, C1 lateral mass and translaminar screws. Appropriate anchor screws should be selected by considering the technical feasibility, safety, strength and so on. These screws are then connected via rods to obtain solid fixation. Shorter fixation using stronger anchor screws, such as pedicle, C1 lateral mass and translaminar screws is desirable if postoperative neck mobility is to be preserved. In this review, the characteristics of these screws are briefly described.

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Although cervical laminoplasty has become the gold standard for the treatment of cervical myelopathy, aggravation of the cervical alignment, intractable axial pain, or C_5 palsy remain troublesome complications after surgery. Preservation of the posterior supporting element of the cervical spine and construction of a rigid enlarged spinal canal are considered to be important for overcoming these problems, and a variety of inventions have been developed for this purpose. Theoretical and practical aspects of less-invasive methods to expand the spinal canal stably, including the open-door expansive laminoplasty with hydroxyapatite implants reported by Kihara and his colleague, are explained in this review

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In the present study, operative complications encountered in 3,486 spinal surgeries performed by a single surgeon were analyzed. Based upon the knowledge of the literature and my personal experience, the incidence, mechanisms and preventive strategies of these complications were examined.

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BACKGROUND : Dexmedetomidine, a highly selective alpha 2-agonist, could be beneficial for patients after neurosurgical operations, because it provides a unique "conscious sedation" (patients appear to be asleep, but are readily roused), with sympathetic suppressive effects. METHODS : Twenty patients were sedated postoperatively with continuous intravenous infusion of dexmedetomidine in the intensive care unit. Measurements of blood pressure and heart rate before the operation and during the infusion were compared by paired t-test. RESULTS : Blood pressure and heart rate were significantly reduced postoperatively (n = 20, p < 0.05). Seven patients, whose preoperative levels of consciousness were clear, exhibited "conscious sedation" after surgery under dexmedetomidine infusion. Neurological examinations could be performed on these patients. Eight patients exhibited bradycardia or hypotension in the intensive care unit. With the exception of one patient with a heart rate less than 40 beats/min, sympathetic suppressive effects of dexmedetomidine were observed in the other seven patients and hemodynamic and general conditions were stable. CONCLUSIONS : We believe that dexmedetomidine is a useful adjunct for the management of postoperative neurosurgical patients in the intensive care unit.

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A prenatally diagnosed aneurysm of the vein of Galen was presented in the fetus of a patient referred to our hospital at 32 weeks of gestation. Head MRI demonstrated bilateral ventricular dilatation, an aneurysm of the vein of Galen and hydrocephalus. A 3,132 g male was delivered by cesarean at 36 weeks of gestation. Although the patient presented with apnea, heart failure and hydrocephalus, we decided on emergency endovascular treatment according to Lasjaunias's neonatal evaluation score (9 points). Angiography showed a choroidal-type aneurysm of the vein of Galen. Transarterial embolization was performed on postnatal day 2, 6, 20, and 29, and transvenous embolization on postnatal day 29. The infant also underwent persistent arterial canal ligation against heart failure on postnatal day 26, and V-P shunting against hydrocephalus on postnatal day 22. Although the head CT revealed SAH after the 4th embolization, the size of the aneurysm was significantly reduced, and recovery from heart failure was also improved due to the reduction of shunt flow. On postnatal day 55, the infant died of progressive hepatic and renal failure. Although the transarterial embolization was useful to reduce the shunt flow and aneurysmal size, thorough treatment should have been provided in the early stage to prevent the eventually fatal multiple organic failure. We discuss the technique of multi-stage embolization and the treatment strategy for this difficult disease.

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