Functional electrical stimulation (FES) for spinal cord injury.

Restoration of respiratory motion by stimulation of the phrenic nerve was investigated. Respiratory motion was restored successfully by introducing a breathing pacemaker to a patient with respiratory disturbance due to upper cervical spinal cord injury. Breathing pacemakers are considered to be more similar to physiological conditions compared to mechanical ventilators. Although the system is very expensive, its cost effectiveness may be excellent, provided that it can be used for long hours each day over an extended period. The system is effective in improving patient QOL because it dramatically increases patient mobility. From these findings, it is concluded that breathing pacemakers should be used more frequently in Japan, and that various forms of support are necessary to cope with economic and other concerns.

Strategy for the treatment of arteriovenous malformations.

The treatment of arteriovenous malformations (AVMs) is still a challenging problem in the neurosurgical field. The deep-seated AVMs are a definite indication for radiosurgery for the small AVMs and with pre-embolisation for the large AVMs. The superficial AVMs are a good indication for surgery. In the case of small AVMs, surgery alone is a viable option; however, in the case of large AVMs, pre-operative embolisation is essential for prevention of NPPB (normal perfusion pressure breakthrough). Embolisation alone cannot be used, except for a small AVM in the non-eloquent cortex. Preoperative embolisation makes surgery easy; however, it causes the surrounding cortex to infarct. Hyperperfusion may occur after the direct removal of high-flow large AVMs, therefore postoperative management will be difficult in these cases. In eloquent cortex minimally invasive surgery is more reliable with respect to the morbidity produced. Therefore in cases of small AVMs in the functional cortex, direct surgery is the only choice. In cases of high-flow large AVMs, surgery and postoperative management are risky because of NPPB. Therefore pre-operative embolisation followed by surgery is a better choice. In high-flow AVMs, local blood circulation is not decreased by temporary clipping of the feeding arteries. So we recommend temporary clipping of all feeding arteries, even away from the nidus where it is easier to control bleeding.

Classification and treatment of vertebral dissecting aneurysm.

BACKGROUND: For many years, dissecting aneurysms of the intracranial vertebral artery were believed to be quite rare. In recent years, because vascular disorders have been studied more thoroughly by three dimensional-computed tomography (3D-CT), angiographically and pathologically, these aneurysms are being reported with more frequency. METHODS: Among the 45 patients diagnosed to have aneurysms arising from the vertebral artery or its branches over a 20-year period, 16 had dissecting aneurysms. The authors present their therapeutic strategy for these patients. Surgery was performed in the 16 patients, the most common technique being clip-occlusion or trapping of the parent artery wherever feasible, in an attempt to optimize cerebral blood flow. The dissecting aneurysms of the vertebral artery were classified into two groups for the purpose of determining a therapeutic approach, namely unilateral and circumferential groups. In the unilateral group, the dissection seemed to involve only on one side of the vessel according to the conventional cerebral angiogram. These patients underwent surgical reconstruction of the vertebral artery by direct clipping. In the circumferential group, the dissection was all around the artery. Proximal clipping or trapping was performed in this group. RESULTS: In six out of eight patients with unilateral dissecting aneurysms, vascular reconstruction was possible by direct clipping. Of these six patients, the surgical outcome was considered excellent in four, fair in one, and one patient died of cardiac failure after 12 days as his preoperative morbid condition remained the same after surgery. Two other patients with unilateral dissecting aneurysms were treated with trapping technique and the surgical outcome was excellent in one patient and good in the other patient. Both patients resumed a normal social life. In five out of eight patients with circumferential dissecting aneurysms, trapping or proximal clipping was performed and the surgical outcome was excellent in two patients, good in one and fair in one patient. One patient with preoperative brain stem infarction died of aspiration pneumonitis after 8 months. Two patients who were noted to have an increase in the size of aneurysm during follow-up angiography underwent a craniotomy with clipping and wrapping of the aneurysm. There was a favorable surgical outcome in both patients. The remaining three patients had Grade IV subarachnoid hemorrhage (SAH) prior to surgery and at autopsy a disturbed vascular wall was detected. CONCLUSION: The authors' experience suggests that when surgically feasible, direct clipping is an effective alternative approach in the treatment of dissecting aneurysms of the vertebral artery in which blood flow in the parent artery is to be preserved.

Pitfalls in aneurysm surgery in acute stages.

Since the dawn of aneurysm surgery, many aneurysms present a more complex challenge. Large size, intimacy with critical perforator branches, deep location, atherosclerotic walls, ruptured aneurysms in the elderly and incorporation of afferent or efferent arteries in the dome represent factors that singly or in combination preclude safe clipping while high pressure circulation continues in the aneurysm. Despite the relative frequency of many class of aneurysms, there remains in the neurosurgical community some degree of confusion regarding the detailed anatomic features and the technical aspects of the treatment of these lesions in the acute stage. In our study of 1,433 cases, we have enumerated four aspects of the pitfalls in aneurysm surgery which should be considered when planning the operative approach to these lesions. These four aspects will be reviewed in relation to the aneurysm surgery: (1) inadequate pre-operative planning; (2) inappropriate response to unexpected premature rupture; (3) poor clipping techniques and clip selection; (4) unintentional occlusion or injury of perforating branches. This discussion will simply elaborate our own conceptual and microsurgical technical approach in dissecting the aneurysms. Minimal retraction was used during the whole surgical procedure. The intracranial brain tension was reduced through a ventricular tap for hydrocephalus or evacuation of hematoma prior to aneurysm surgery. A venous pathway was established for blood circulation. Sharp dissection, using our newly designed jet irrigation bipolar suction method was employed. Regarding the clipping of the aneurysm, we used the tentative clipping and the dome coagulation method thereby preventing the ischemic changes and shortening of the entire clipping procedure. Although the strategies, discussed represent simply our approach to this problem, the principles included have proven quite successful and have allowed safe and definitive treatment in the overwhelming majority of patients and also options to overcome the pitfalls in aneurysm surgery.

Effects of new titanium cerebral aneurysm clips on MRI and CT images.

We studied the effects of newly developed aneurysm clips made of a titanium alloy (manufactured by Aesculap, A.G.) on the quality of MR and CT images. Prior to clinical application in twenty patients, the effects of five types of conventional aneurysmal clips on MR images were examined utilizing a phantom. When compared with conventional aneurysm clips, the new titanium clips produce only limited artifacts and yielded improved images in patients who underwent aneurysm clipping post-operative.

New jet irrigation bipolar system.

Irrigation bipolar systems are particularly useful for the washout of hematomas in subarachnoid hemorrhage during the acute stage of surgery and for preventing adherence of tissue to the bipolar tips during coagulation. These systems have become essential tools, and numerous improvements have been made to them. First, regarding the flow volume, both the interval of droplets and the size of individual water droplets can be adjusted. Second, this system is equipped with two major functions. The first is a preirrigation function, in which a small amount of irrigation water flows before operation of the bipolar coagulation. This wets the bipolar tips, eliminating any heat remaining from the previous use. Another function is postirrigation; after the coagulation has stopped, continuous irrigation is quickly provided to achieve a standby state by cooling down the tissue and the tips of the bipolar forceps. By using both of these functions, mild coagulation without adherence of burned tissue and clots to the bipolar forceps and minimization of residual heat during frequent use can be achieved. This article describes the new jet irrigation bipolar system and the use of an actual system that combines jet irrigation functions with the new cooling functions.