The Japan Adult Moyamoya (JAM) Trial was a unique randomized controlled trial demonstrating the effectiveness of direct bypass surgery for hemorrhagic moyamoya disease. Prespecified subgroup analysis of the trial results demonstrated that posterior dominant initial hemorrhage is a significant predictor of rebleeding and an effect modifier for surgery. Periventricular anastomoses, fragile collaterals formed by the lenticulostriate arteries, thalamic perforators, and choroidal arteries, might be a clue to the mechanism of high rebleeding risk related to posterior dominant hemorrhage. Angiographic analyses of the JAM Trial revealed that choroidal collaterals and the involvement of the posterior cerebral artery (PCA) were associated with posterior dominant hemorrhage. Accumulating additional knowledge to better understand the role of the choroidal artery and PCA might promote further progress in the surgical treatment for hemorrhagic moyamoya disease.
The introduction of the flow diverter induced a major paradigm shift in the treatment of giant intracranial aneurysms because of its efficacy and treatment durability. Using a flow diverter enables the complete reconstruction of the diseased segment of the intracranial artery harboring a giant aneurysm rather than treating the aneurysm itself. A proper understanding of the current flow diverter technology particularly its pros and cons, is the key to incorporating it into the conventional treatment options. Additionally sharing the knowledge acquired through clinical experience is an important factor to improve the procedural safety. The ability to anticipate the technical difficulty and the risk associated with flow diverter treatment in each case is an essential part of the requisite skillset, as much as the technical part. Continuous device improvements and compiling good quality clinical data will increase the role of flow diverter in the treatment of giant intracranial aneurysms.
The continued development and improvement of devices is the most important factor to advance neuro-endovascular therapy. The endovascular treatment of intracranial aneurysms started with detachable coil technology and has been further developed with adjunctive device technology, including the hyper compliant balloon and the neck bridge stent. These technologies are all focused on tightly packing aneurysm with coils. The flow diverter operates on a totally different theory, whereby blood flow into the aneurysm is regulated with a fine mesh stent to achieve occlusion and shrinkage of the aneurysm. The Pipeline Flex was approved in 2015 and we have just started to evaluate this new technology in Japan. However, there will still remain some aneurysms that cannot be cured by the flow diverter. To treat these, we will have a new range of innovative devices, the PulseRider, WEB, Medina and others in the near future. In the field of carotid disease, carotid artery stenting has already overtaken endarterectomy in Japan with its acceptable results and patient desire for a less invasive modality. But, periprocedural ischemic stroke is still more frequent in CAS. A new generation of micro-mesh stents will hopefully resolve this problem beginning with the CASPER approved study just started in Japan. Average risk CEA patients can now enroll in this study and. Going forward, many new innovative devices will continue to be deployed in the field of neuro-endovascular therapy. As always, we should safeguard both their appropriate use and patient safety in order to best contribute to the development of this field.
This is a review paper of a variety of surgical techniques and approaches to the brainstem. Brainstem surgery is indicated to remove lesions, such as cavernous malformations, gliomas, hemangioblastomas, and so on. As a rule, an incision should be made on the brainstem at the point where the lesion is the closest to the brainstem surface. To simulate the entry route, the “two-point method” has been proposed. Although, it is necessary to understand the anatomy of the important structures in the brainstem, simulation with preoperative imaging studies is also useful to understand deviated structures presented by the lesions. In order to minimize the damage due to surgery, intraoperative monitoring is very useful, such as motor evoked potential (MEP), auditory brainstem response (ABR), somatosensory evoked potential (SEP), electrocardiogram (EEG), and electrical stimulation of the facial nerve.
A typical approach to the dorsal midbrain is the occipital transtentorial approach (OTA). To approach the midbrain from the ventral side, the orbitozygomatic approach or trans-lamina terminalis approach is useful. The trans-fourth ventricle approach is used to approach the pons or medulla oblongata from behind. To widely open the fourth ventricle, trans-cerebellomedullary fissure (CMF) approach is useful. As for an antero-lateral approach to the pons and medulla oblongata, the subtemporal approach, anterior petrosal approach, and far lateral (transcondylar) approach are all approaches of choice in avoiding injuries to the pyramidal tract.
The number of osteoporotic vertebral fracture patients has been increasing in line with our aging society, which has become an serious social problem. Most patients with an osteoporotic vertebral fracture can show a good clinical course after conservative treatment. However, some patients develop prolonged low back pain or delayed neurological deterioration. It is important for us to build an appropriate system and operate on them in appropriate time. We operate about 400 times a year to treat patients with spinal disorders and have cooperated with the local medical community to treat osteoporotic vertebral fracture patients. On this occasion, the state of treatment for osteoporotic vertebral fractures at our department was investigated.
Patients diagnosed with osteoporotic vertebral fractures from January 2011, when balloon kyphoplasty (BKP) was introduced into our department, to September 2015 were retrospectively investigated. Clinical scores (JOA score, VAS, ODI) and radiological findings (vertebral body height, local kyphotic angle) of the patients who underwent an operation were evaluated. The patients who underwent BKP were followed up until 3～6 months after the operation to evaluate the immediate effect of BKP, and patients who underwent long-segment posterior fixation for 2～3 years, to evaluate the influence of instrumentation on the osteoporotic vertebral bodies.
420 patients were diagnosed as osteoporotic vertebral fractures at our department during the period. In total, 159 patients were hospitalized for treatment, and 62 patients were discharged from our department after conservative treatment. 91 BKPs (77 cases), 19 long-segment posterior fixations were performed. Only one case underwent just decompression. BKP had significantly better results until 3～6 months after the operation and was proved to give the patients immediate relief although secondary fractures sometimes occurred. Because of the fragility of the osteoporotic vertebral body, the long-segment posterior fixation with spinal instrumentation might show unfavorable result. However, relatively satisfactory condition can be obtained during 2～3 year follow up period.
The state of treatment for osteoporotic vertebral fractures at our department was investigated. Clinical scores and radiological findings of the patients who underwent BKP or long-segment posterior fixation were significantly good.
Lumbar disc herniation (LDH) is commonly encountered in daily medical practice, and the status of its treatment in general has been previously discussed. However, assessing the status of consultation and treatment of LDH at the Spinal Disorders Center is useful for establishing treatment principles.
We retrospectively assessed 707 patients with LDH treated in our facility during the last 5 years. We reviewed their age, sex, Japanese Orthopaedic Association (JOA) scores, visual analog scale (VAS) scores, hernia level (L1/2, L2/3, L3/4, L4/5, L5/S1), hernia protrusion direction (medially, laterally, foraminally, extraforaminally), occurrence of spontaneous hernia reduction, surgical rate, surgical method (discectomy, laminectomy, discectomy with fusion), recurrence, complications, and need for reoperation, among other items.
We found that the average age at onset was older than that in previous reports because of the increase in our aging population in recent years. Also, the surgical rate (38%) was higher than in other reports because of the specialty characteristics of the Spinal Disorders Center. In addition, we were able to determine the characteristics of LDH at each level and each type by classifying LDH according to the level and the hernia protrusion direction (four types) in detail. The surgical rate for upper LDH tended to be higher for the medial protrusion type. The surgical rate for lower LDH tended to be higher for the extraforaminal type. Moreover, upper LDH (foraminal type) more often underwent lumbar interbody fusion with discectomy than any other LDH type at any of the other levels.
This study has provided data in one of neurosurgical facilities in Japan. We believe that it could help promote more surgical activity by Japanese neurosurgeons in this field.
We report here a case of eye pain treated with microvascular decompression (MVD). A 42-year-old man had experienced left eye pain with conjunctival injection and tearing for six years. On the basis of his symptoms, we diagnosed him as having first division trigeminal neuralgia or short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Magnetic resonance cisternography showed that the left trigeminal nerve was in contact with and distorted by a blood vessel. Therefore, MVD was performed and the offending vessel was found to be the petrosal vein. The eye pain disappeared immediately after MVD. It is difficult to distinguish first division trigeminal neuralgia from SUNCT simply based on symptoms. The eye pain was definitively diagnosed as first division trigeminal neuralgia. Careful diagnosis is required to distinguish classical trigeminal neuralgia from SUNCT.