A New Method of Orbital and Cavernous Sinus Venography
Akira Takaku and Jiro Suzuki
Nonsurgical treatment of chronic subdural hematoma
Jiro Suzuki and Akira Takaku
✓ A nonsurgical treatment consisting of osmotherapy with 20% Mannitol was performed on a consecutive series of 23 male patients with chronic subdural hematoma, ranging from 21 to 71 years in age, including seven serious cases. Disappearance or marked reduction of the hematoma content and complete clinical recovery were obtained in 22 patients. The duration of the treatment was 12 to 106 days. Follow-up study from 8 months to 3½ years showed no sequelae, recurrence, or complications.
Use of balloon occlusion and substances to protect ischemic brain during resection of posterior fossa AVM
Jiro Suzuki, Akira Takahashi, Takashi Yoshimoto, and Hirobumi Seki
✓ The successful resection of a large posterior fossa arteriovenous malformation (AVM) is reported. A balloon catheter was used for temporary intraoperative occlusion of the basilar artery and feeding vessels of the AVM. Prior to occlusion of these arteries, newly tested substances to protect the ischemic brain were administered to prolong occlusion time. Resection of the AVM was completed without complication, and the patient returned to normal life. This is a useful intraoperative procedure for the resection of AVM's considered inoperable by conventional approaches.
Vascular anomalies associated with aneurysms of the anterior communicating artery: microsurgical observations
Akira Ogawa, Michiyasu Suzuki, Yoshiharu Sakurai, and Takashi Yoshimoto
✓ Direct operations were performed on 206 patients with aneurysms of the anterior communicating artery (ACoA) using a bifrontal craniotomy and an interhemispheric approach. A total of 44 (21.4%) of these patients had vascular anomalies in the vicinity of the ACoA; these included a median artery of the corpus callosum (MACC) in 27 cases (13.1%), duplication of the ACoA in 20 (9.7%), and duplication of the A1 segment of the anterior cerebral artery in one (0.5%). A retrospective study of the angiograms indicated that diagnosis of the A1 or ACoA duplication was not possible; only 11 (41%) of the 27 MACC's were easily identified, while eight (30%) could not be diagnosed. The majority of the cases of ACoA aneurysms with MACC (81.5%) showed trifurcation of the ACoA, A2, and MACC. The operative results in the patients with MACC did not differ significantly from the results of the entire ACoA aneurysm series. From the above study it is concluded that, regardless of whether a vascular anomaly has been identified preoperatively, ACoA aneurysm surgery should be undertaken with that possibility in mind. A bifrontal craniotomy and an interhemispheric approach has the advantage of allowing for a wide operative field and the attainment of a good understanding of the vascular structures near the ACoA. It is particularly useful in cases of vascular anomaly in this region.
A combined orbitozygomatic infratemporal epidural and subdural approach for lesions involving the entire cavernous sinus
Akira Hakuba, Kiyoaki Tanaka, Toshihisa Suzuki, and Shuro Nishimura
✓ The authors present four cases of vascular lesions and 10 cases of tumors involving the cavernous sinus. They were operated on via a combined orbitozygomatic infratemporal epidural and subdural approach. With this approach, multisided exposure of the cavernous sinus can be achieved via the shortest possible distance with minimal retraction of the neural structures in and around the cavernous sinus. In one patient the carotid artery had been occluded previously, but in the other 13 patients it was preserved. There was no mortality, and all patients except one returned to work within 6 months after surgery.
Transvenous copper wire insertion for dural arteriovenous malformations of cavernous sinus
Akira Takahashi, Takashi Yoshimoto, Kiyoshi Kawakami, Takayuki Sugawara, and Jiro Suzuki
✓ Therapeutic embolization by means of transvenous copper wire insertion was performed in five patients with dural arteriovenous malformations (AVM's) of the cavernous sinus. In each case, angiograms had shown that the AVM's were supplied from both internal and external carotid arteries, which was thought to render complete transarterial embolization difficult. A No. 2.5 French Teflon catheter was introduced into the affected cavernous sinus through the superior ophthalmic or internal jugular vein with the aid of a flexible mini guide wire. Copper wires were pushed by the guide wire into the cavernous sinus until the disappearance or a sufficient decrease in the arteriovenous shunt was noted. The patients' symptoms resolved or improved without any severe complications. Angiography revealed complete disappearance of the lesion immediately after treatment in three cases and follow-up angiography taken within 8 months showed no arteriovenous shunt in any patient. This method is a promising treatment for dural AVM's when conventional transarterial embolization is thought to be difficult.
Clinical course of acute middle cerebral artery occlusion
Takashi Yoshimoto, Akira Ogawa, Hirobumi Seki, Tetsuo Kogure, and Jiro Suzuki
✓ Knowledge of the natural course of stroke patients has become increasingly important since new therapeutic methods have been proposed for patients with cerebral infarction in the acute stage. In order to clarify the acute stage of this disease, 188 patients admitted within 24 hours after onset of middle cerebral artery (MCA) occlusion were followed for 2 months, and data relating to mortality and changes in disturbances of consciousness and motor function were investigated. It was shown that the prognosis for MCA occlusion cases is poor, and about 80% of these patients are unable to return to their previous lifestyle. The level of consciousness in the acute stage is a good index for estimating the patient's quality and time of survival, and motor function in the acute stage is a good indicator of functional recovery. Thus, when evaluating the effectiveness of a new therapy for cerebral infarction, rapid improvement in the acute stage before and after treatment should be carefully noted.
Monitoring visual evoked potentials during retraction of the canine optic nerve: protective effect of unroofing the optic canal
Akira Akabane, Kiyoshi Saito, Yoshio Suzuki, Masato Shibuya, and Kenichiro Sugita
✓ To evaluate the effects of unroofing the optic canal during retraction of the optic nerve, the authors monitored changes in visual evoked potentials (VEPs) stimulated by a light-emitting diode in the canine model. At rest, an early VEP wave was reliably observed with an amplitude of 8.2 ± 0.6 µV and a latency of 51.5 ± 0.7 msec; this wave was named N50. The intracranial optic nerve was retracted using a weight of 5, 10 or 50 g. The earliest change in VEP noted during retraction was a reduction in N50 wave amplitude. The length of time required until N50 amplitude decreased to 50% of the control group (T50) was 10.7 ± 1.8 minutes with a weight of 5 g, 4.9 ± 0.7 minutes with 10 g, and 2.9 ± 0.4 minutes with 50 g, with statistically significant differences between the groups. Retraction of the optic nerve with all weights finally resulted in the disappearance of the N50 wave. The amplitude of the N50 wave recovered fully to control size when retraction was released immediately after the wave disappeared. The time course of amplitude recovery did not differ significantly between groups. Unroofing the optic canal prolonged the T50 during retraction significantly to 20.7 ± 2.9 minutes with a weight of 5 g, 18.9 ± 4.2 with 10 g, and 9.0 ± 2.4 with 50 g. These results demonstrate that unroofing the optic canal can protect the optic nerve from damage during operations that require optic nerve retraction.
Spasm of the Cervical Portion of the Carotid Artery and its Surgical Treatment
Jiro Suzuki, Akira Takaku, Shigeaki Hori, Itaru Ohara, and Ryungchan Kwak
Schwannoma arising from the intermediate nerve and manifesting as hemifacial spasm
Akira Kudo, Michiyasu Suzuki, Naohiko Kubo, Kiyoshi Kuroda, Akira Ogawa, and Yuzo Iwasaki
✓ This 35-year-old man presented with left facial spasm that had persisted for 10 months. Microvascular decompression was performed to relieve the symptom. No responsible vessel could be identified during surgery, but a small mass seeming to arise from the intermediate nerve and compressing the seventh cranial nerve was removed. The histological diagnosis was Antoni-B type schwannoma. This unique case of schwannoma arising from the intermediate nerve was recognized by means of an operative microscope, and supports the idea that portions of the seventh nerve schwannoma originate from the components of the intermediate nerve.