Orbitocraniobasal approach for anterior communicating artery aneurysms.

We describe an orbitofrontotemporobasal craniotomy technique that allows excellent access to anterior communicating artery aneurysms. This orbitocraniobasal approach is particularly useful for the surgical treatment of ruptured aneurysms in the acute stage of subarachnoid hemorrhage, when retraction of the brain needs to be kept to a minimum. With this approach, retraction of the orbital contents decreases the amount of retraction of the brain to such an extent that a brain spatula is not necessary for access to the anterior communicating artery complex. The procedure is described, as is a modification of the approach for removal of large tumors on the skull base.

Unusual angiographic changes in a dissecting aneurysm of the basilar artery: case report.

A patient with unusual angiographic changes of a dissecting aneurysm of the basilar artery is presented. Initial angiography and magnetic resonance imaging revealed a typical dissecting aneurysm. However, a follow-up study demonstrated a saccular aneurysmal dilatation of the proximal part of the dissection. The importance of the follow-up study, particularly in regard to the usefulness of magnetic resonance imaging and the pathogenesis of this change are discussed.

Traumatic intraventricular hemorrhage: report of twenty-six cases and consideration of the pathogenic mechanism.

A series of 26 patients suffering traumatic intraventricular hemorrhage (IVH) after closed head injury is reviewed, and the pathogenic mechanism of the traumatic IVH is discussed considering the site of origin of the IVH. Computed tomographic detection of the origin of the IVH was possible in 15 patients (Group 1): 6 had frontal or temporal contusional intracerebral hemorrhage spreading into the ventricle (Subgroup A), 5 had the original hemorrhage in the caudate nucleus (Subgroup B), and 4 originally bled in the thalamus (Subgroup C). The origin of the IVH was not determined in 11 patients (Group 2): 6 had concomitant hemorrhage around the brain stem (Subgroup D), and 5 had small IVH with or without small intracerebral hemorrhage (Subgroup E). The site of impact was not uniform in Subgroup A, whereas the other four subgroups usually had frontal or occipital impact. In Subgroup A, the IVH was discovered more than several hours after trauma. In the other four subgroups, however, the IVH was detected in as short a time as 0.5 to 1.5 hours after trauma. In Subgroups B and C, the impact along the long axis of the skull and the early occurrence of hemorrhage in the basal ganglia suggest that shear injury between the perforating vessels and the basal ganglia may be the responsible mechanism. The several other possible mechanisms in Subgroups D and E are reviewed and discussed in relation to diffuse brain injury.

Telecanthal approach for meningiomas in the ethmoid and sphenoid sinuses.

In three cases involving meningiomas in the ethmoid and sphenoid sinuses, transbasal spreading of the interocular distance (telecanthal approach) was used for tumor removal and reconstruction of the skull base. This telecanthal approach involves 1) bilateral en bloc removal of the superior lateral rim of the orbit, the nasal bone, and the posterior lateral wall of the orbit; 2) detachment of the medial canthal ligaments; and 3) spreading of the interocular distance. This approach provides a wide working space beneath the anterior half of the midline skull base, and needs neither a facial incision nor significant retraction of the brain. The surgical technique and its modification are described. The discussion focuses not only on comparisons with other techniques, but on the indications for this approach. Meningiomas originating in the paranasal sinuses are rare; a brief review of the literature concerning the clinicopathological features and pathogenesis is also given.

Experimental vasospasm in cultured arterial smooth-muscle cells. Part 1: Contractile and ultrastructural changes caused by oxyhemoglobin.

Smooth-muscle cells were cultured from rat aortic media, then oxyhemoglobin and other agents including serotonin, norepinephrine, and angiotensin II were added separately to the medium. Contractile and ultrastructural changes of the cells were examined with electron microscopy during the first 2 weeks of incubation. Oxyhemoglobin not only produced progressive contraction of the arterial smooth-muscle cells, but it also caused ultrastructural changes that resembled myonecrosis. In contrast, there was no evidence of progressive contraction or ultrastructural changes either in control cultures or in cultures with the other vasoactive agents. Although washout of oxyhemoglobin 3 hours after administration prevented continued contraction of the cells, washout 24 hours or longer after administration had no preventive effect. Judging from these results and from the fact that the culture medium was changed every 2 days, it is unlikely that accumulation of exogenous vasoactive agents caused these changes. The contraction and suggestive myonecrosis of the arterial smooth-muscle cells are probably caused by some intrinsic process initiated by oxyhemoglobin. The culture of cerebral arterial smooth-muscle cells requires further technical improvement; nevertheless, these results obtained with the smooth-muscle cells of rat aortic media indicate that arterial smooth-muscle cells in culture provide a promising new experimental model for chronic in vitro study of cerebral arterial spasm. It is suggested from these results that cerebral arteries are particularly prone to vasospasm because of structural differences as compared to noncerebral arteries.

Zygomatic approach for lesions in the interpeduncular cistern.

Lesions in the interpeduncular cistern include basilar tip aneurysms, craniopharyngiomas, and chordomas. The surgical approach to these lesions presents a special technical problem, particularly when they are located high in the interpeduncular fossa. For the purpose of minimizing brain retraction and achieving excellent exposure within the interpeduncular cistern, the authors have developed a new surgical technique which involves detachment of the zygomatic arch. The patient is placed in the supine position with the head rotated 45 degrees to the contralateral side and tilted down 30 degrees so that the surgeon can see into the interpeduncular cistern obliquely from below. The zygomatic arch of the temporal bone as well as a portion of the lateral orbital rim (the posterior ridge of the frontal process of the zygomatic bone) is removed to expose the anterior temporal base. With posterior retraction of the temporal lobe, the arachnoid membranes covering the Sylvian stem are opened in a retrograde fashion until the tentorial edge is sufficiently exposed. The posterior communicating artery and the optic tract are elevated to enter the interpeduncular cistern, after which the oculomotor nerve is dissected free of its surrounding arachnoid membranes and displaced posteroinferiorly. Two patients with basilar tip aneurysms were operated on with this zygomatic approach, and a subtemporal modification of the zygomatic approach was used to treat a craniopharyngioma and a chordoma in two other patients. The procedure is described and a short description of its clinical use is given.

Basal interfalcine approach through a frontal sinusotomy with vein and nerve preservation. Technical note.

The authors describe a new method for a frontal interhemispheric approach when treating craniopharyngiomas of the third ventricle or anterior communicating artery aneurysms. This technique ensures preservation of the bridging veins and the olfactory nerves. This "basal interfalcine approach" involves a craniotomy in the centrobasal portion of the frontal bone (the frontal sinus), removal of the inner tables and the crista galli, and splitting the basal portion of the falx into two leaves, through which the basal interhemispheric fissure is opened. The olfactory nerves are protected by the leaves of the falx, and the bridging veins are preserved because the approach is low enough to spare them. The surgical techniques are described together with a unilateral variation of this approach. The significance of preserving the bridging veins is discussed in connection with avoidance of postoperative contusional hemorrhage.

Altered reactivity of hemolysate-treated cultured smooth-muscle cells from rabbit basilar artery determined by digital imaging microscopy.

During culture, smooth-muscle cells obtained from rabbit basilar arteries were examined for contractile activity by means of differential interference microscopy with a video analysis system (digital imaging microscopy system). This system proved useful for observing the contraction and ultrastructural changes of the living cells. Hemolysate-treated cells showed augmented responses to 5-hydroxytryptamine and leukotriene C4, but not to KCl. This augmented response diminished gradually during the culture period. Both a phospholipase C blocking agent, 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC), and a myosin light chain kinase blocking agent, 1-(5-chloronaphthalenesulfonyl)-1H-hexahydro-1,4-diazepine (ML-9), suppressed this augmented response. Protein kinase C activity of the cells, as measured by Western blot analysis, did not increase during the period of culture with hemolysate. The results obtained suggest that hemolysate had the following effects on the cells: 1) acute but gradual contraction of the cells; 2) augmentation of cellular responses to vasoactive agents; and 3) progressive contraction and morphological alteration of the cells. Possible mechanisms by which hemolysate exerts these effects are discussed, taking into consideration the interrelationship between these effects.

Wrap-clipping with a Dacron mesh silastic sheet. Technical note.

A technique combining wrapping and clipping using a Silastic sheet coated with Dacron mesh is described for treatment of fusiform or broad-based cerebral aneurysms. This sheet is easily tailored to wrapping the aneurysm base while avoiding involvement of the cranial nerves or branching vessels. The sheet is semitransparent so that the caliber of the newly constructed parent artery is easily adjusted during wrap-clipping. After the aneurysm and the parent artery have been circumferentially wrapped with the sheet, aneurysm clips are applied on the sheet so that the base of the aneurysm is clipped between the two leaves of the sheet. This wrap-clipping technique avoids the risks involved in extracting the aneurysm from the parent artery. The Dacron mesh coating the outer surface and sufficient clip closing pressure are both helpful in preventing the clip blades from sliding. Similar previously reported techniques are reviewed and discussed in detail.

Subdural tension pneumocephalus following surgery for chronic subdural hematoma.

The computerized tomography (CT) findings were analyzed in five cases of subdural tension pneumocephalus following surgery for chronic subdural hematoma. They were compared with CT scans in 14 cases of asymptomatic subdural pneumocephalus. In this study, two new CT findings were identified that suggest increased tension of the subdural air. Subdural air separates and compresses the frontal lobes, creating a widened interhemispheric space between the tips of the frontal lobes that mimics the silhouette of Mt. Fuji. The presence of air between the frontal tips associated with massive air inclusion over the frontal lobes presumably indicates increased tension of the subdural air. The "Mt. Fuji sign" was seen in four of the five cases with subdural tension pneumocephalus. The other finding was the presence of multiple small air bubbles scattered through several cisterns ("air bubble sign"). It is postulated that these air bubbles enter the subarachnoid space through a tear in the arachnoid membrane caused by increased tension of air in the subdural space. This finding was seen in four cases with subdural tension pneumocephalus. These two CT findings are helpful in making a diagnosis of subdural tension pneumocephalus following surgery for chronic subdural hematoma.

Indications for surgical treatment of putaminal hemorrhage. Comparative study based on serial CT and time-course analysis.

Serial computerized tomography (CT) scans were correlated with a precise time-course analysis of the neurological condition of 180 patients with hypertensive putaminal hemorrhage. All patients entered the study within 3 hours of the ictus. In this series, 111 patients were treated conservatively and 69 surgically. The neurological condition of each patient was measured by means of a newly proposed grading system for intracerebral hemorrhage-intracranial hemorrhage (ICH grade) which is a modification of the Glasgow Coma Scale. Serial CT scans revealed that most hemorrhages were completed within 6 hours after ictus. Based on the ICH grade at 6 hours postictus, a clinical classification of the severity of putaminal hemorrhage was defined: fulminant, rapidly progressive, slowly progressive, and nonprogressive. According to this classification, precise time courses of the ICH grade were compared between the conservative and surgical treatment groups in a 7-day postictal period. Activities of daily living at 6 months after ictus were also compared. Surgical treatment for a rapidly progressive hemorrhage appears to be beneficial if undertaken in patients under 65 years of age. Surgery in a slowly progressive hemorrhage should be considered only in a small number of patients who deteriorate neurologically with conservative treatment. In this series of patients, surgical treatment of fulminant and nonprogressive hemorrhage was not likely to improve the quality of life or functional recovery. Regardless of treatment modality, CT provided evidence that patients with anterior capsular hemorrhage (16% in this series) showed good recovery of motor and speech function.

A new intracranial Silastic encircling clip for hemostasis. Technical note.

A new encircling clip made of a silicone tube has been designed for treating accidentally injured cerebral vessels. No special holders are necessary. This clip can be tailored depending on the shape of the injured vessel. The clip is a simple and effective tool for achieving complete hemostasis.

Cranio-nasal median splitting for radical resection of craniopharyngioma.

A new surgical approach for radical resection of craniopharyngioma is presented. This approach (cranio-nasal median splitting) involves craniotomy in the centre of the frontal bone, removal of the median portion of the supraorbital bar that incorporates the nasal bone, and detachment of the medial canthal ligaments. The frontal lobes, the cribriform plates, the planum sphenoidale, and the upper nasal cavities are split in the midline. The extraventricular surface of the hypothalamus, the pituitary stalk, and the posterior portion of the Willis' arterial ring are well visualized through the midline infrachiasmatic route. The intraventricular surface of the hypothalamus is also visible in the same operative field through the lamina terminalis and/or the anterior portion of the corpus callosum. This excellent visualization is quite helpful for minimizing operative injury to the hypothalamus and the pituitary stalk whichever surface of the third ventricular floor the tumour is situated upon. Three cases of craniopharyngioma operated upon by this approach are presented. Discussions are focused not only on the indication, but on the advantages and disadvantages of this approach. The surgical techniques for reconstruction of the cranial base are also described, together with some precautions that should be taken to prevent possible postoperative complications.

Microsurgical thromboendarterectomy of the cavernous carotid artery--case report and surgical technique.

A 53-year-old male suffered a transient right hemiparesis and left monocular blindness. Angiography revealed 80% stenosis of the cavernous carotid artery. Microsurgical thromboendarterectomy was performed by a direct approach through Parkinson's triangle. During surgery, the carotid circulation was transiently trapped between the cervical and the supraclinoid segment and the trapped arterial lumen was irrigated with heparinized saline. Soft elastic lesion was easily removed. Cavernous carotid thromboendarterectomy through a direct approach is considered as a suitable operation for the solitary and localized stenotic lesions of the cavernous carotid artery, although this operation has not yet been reported to date.

[Comparison of five modes of dialysis in neurosurgical patients with renal failure].

In neurosurgical patients with renal failure, dialysis entails specific problems, chief of which is increased intracranial pressure and progressive brain edema as a result of rapid lowering of the serum osmolality. Another major problem is a tendency to hemorrhage, in response to either systemic heparinization or insufficient dialysis. The authors describe the results obtained with hemodialysis (HD), continuous arteriovenous hemofiltration (CAVH), continuous ambulatory peritoneal dialysis (CAPD), continuous peritoneal dialysis (CPD), and intermittent peritoneal dialysis (IPD). Nine patients were treated with HD, one with CAVH, five with CAPD or CPD, and two with IPD. Three of the six patients treated with continuous dialysis (CAVH, CAPD, and CPD) died, whereas intermittent dialysis (HD and IPD) carried an 82% mortality rate (nine of 11 patients). The causes of death were progressive brain edema in three cases, intracranial hemorrhage in three, gastrointestinal bleeding in three, overhydration due to insufficient dialysis in one, septicemia in one, and rupture of a cerebral aneurysm in one. Continuous dialysis appeared to be superior to intermittent dialysis in these neurosurgical patients in that it produced less brain edema and was less often associated with hemorrhage due to insufficient dialysis. In HD and CAVH, systemic heparinization was also thought to account for the high incidence of hemorrhage. However, CAVH with short half-life anticoagulants may be useful in patients who have abdominal complications and are therefore not suitable candidates for peritoneal dialysis.

[Traumatic aneurysm occurring after surgical procedure of large cerebral aneurysm].

A case of intracranial traumatic aneurysms occurring after surgical treatment of a large cerebral aneurysm is reported. A 56-year-old man was admitted to our department with complaints of headache, nuchal pain and nausea. Left carotid angiography (Lt-CAG) revealed a large aneurysm, measuring 20 mm in maximum diameter, of the azygos anterior cerebral artery. Successful clipping operation was performed on day 17 of subarachnoid hemorrhage. Unfortunately, small cortical branches were pulled out during the procedure from the right pericallosal artery. The postoperative Lt-CAG showed formation of two other aneurysms. Second operation was done on day 28 after the first operation. These aneurysms were located at the previously injured sites on the right pericallosal artery. From the history sited above, we diagnosed them as traumatic aneurysms. The second operation resulted in successful obliteration of these two traumatic aneurysms. Literature review yielded 25 similar cases, and the authors discuss the etiologic factors of the traumatic aneurysm due to surgical procedure.

[A case of alpha-fetoprotein producing primary intracranial embryonal carcinoma treated with combination chemotherapy with cis-platinum, vinblastine and bleomycin (author's transl)].

A case of alpha-fetoprotein (AFP) producing primary intracranial embryonal carcinoma was reported with special reference to the chemotherapy. The patient was a 14-year-old male who had suffered from vomiting and disturbance of consciousness. CT scan revealed a tumor originating in the anterior part of the third ventricle and expanding into both lateral ventricles. Right frontotemporal craniotomy was performed and the tumor was totally removed under the microscope. The histological diagnosis was embryonal carcinoma. Inspite of the elevated amount of AFP in the serum, we could not verify the yolk sac element in the surgical specimen. Three months later, he became drowsy and another CT scan revealed recurrence of the tumor. Ommaya's reservoir was placed and CSF was drained to control the intracranial hypertension. But the disturbance of consciousness did not improve. We then started a combination chemotherapy with cis-platinum, vinblastine and bleomycin. Cis-platinum was given in a dosage of 20 mg/m2 body surface area as a 15 min. intravenous infusion for 5 consecutive days every 3 weeks for three courses. Vinblastine was given in a dosage of 0.4 mg/kg body weight intravenously for 2 consecutive days every 3 weeks for three courses. Bleomycin was given in a dosage of 30 mg intravenously 6 hours after vinblastine weekly for a total of 12 weeks. The AFP level of the serum and CSF was monitored every several days. After the chemotherapy, the AFP level of the serum and CSF decreased. Repeated CT scan revealed no evidence of tumor. His clinical condition improved remarkably. Toxicity was vomiting, proteinuria and leukopenia, but not so severe. Proteinuria continued after the chemotherapy, but BUN and creatinine did not elevate. It was emphasized that the combination chemotherapy with cis-platinum, vinblastine and bleomycin is effective remission-induction treatment for AFP producing primary intracranial embryonal carcinoma.

[Surgical approach for jugular foramen neurinoma--combined suboccipital and infralabyrinthine approach using a rotatable head holder].

A 36-year-old male with jugular foramen neurinoma was operated upon using a rotatable head holder, which enables the surgeon to rotate the patient's head at any time during the procedure and to gain access in multiple directions to the tumor. The tumor was situated primarily in the jugular foramen and showed partial extension into intracranial as well as into extracranial space. The patient was placed in the lateral position with a rotatable head holder, which allows rotation of the patient's head with the range of 10 degrees face up to 80 degrees face down from the horizontal plane. A linear skin incision was made, beginning behind the auricle and extending along the anterior margin of the sternocleidomastoid muscle, and the sternocleidomastoid muscle was divided just below the tip of the mastoid process. During mastoidectomy and suboccipital craniectomy, the patient's head was rotated 15 degrees face down and sigmoid sinus was exposed toward the jugular foramen, meanwhile the posterior fossa dura mater was opened and the intracranial portion of the tumor was removed with the head positioned 45 degrees-60 degrees face down. The patient's head is then turned 30 degrees face down and the facial canal was opened to displace the facial nerve forward. This oblique posterior approach minimized facial nerve displacement and provided excellent exposure of the large tumor rest which was situated mainly in the jugular foramen and partly extended extracranially. The rotatable head holder allows excellent access in multiple directions and is very helpful in approaching to jugular foramen neurinomas which grow primarily in the jugular foramen and extend both into intra- and extracranially.

[Unilateral exophthalmos caused by organized hematoma of the orbit--report of a case (author's transl)].

The authors reported a case with unilateral proptosis of over ten years' duration due to organized hematoma of the orbit. It has generally been accepted that any given hemorrhage within the orbit can be resolved in a relatively short period of time. Persistent intraorbital hematoma, therefore, in the form of organized hematoma is very unusual in incidence and has been reported very few in the literature. Our patient presented himself with a ten-and-several-year history of unilateral exophthalmos, limited ocular movement and decreased visual acuity on the involved side. There was no specific symptom when compared with the other intraorbital tumors. Total resection of the tumor was performed through transcranial frontozygomatic approach. Histopathologic examination revealed evidence of organized hematoma without definite sources of bleeding such as microangioma, microaneurysm or arteriovenous malformation. Retrospective review of history failed to uncover episodes of hemorrhagic tendency or direct trauma to the head or the orbit. Subsequently a diagnosis of spontaneous organized hematoma was made. Great emphasis was laid on the fact that CT-scan was one of the most useful diagnostic tools. Our surgical approach was introduced and discussed.

[Subdural tension pneumocephalus following surgery of chronic subdural hematoma].

Subdural tension pneumocephalus (TP) following surgery for chronic subdural hematoma was analyzed in 5 cases from clinical standpoints of view, especially from CT findings. The cases were compared with 14 cases of subdural asymptomatic pneumocephalus (AP). The TP tends to complicate elderly patients who showed a poor re-expansion of the brain after irrigation of bilateral chronic subdural hematoma. In such patients, it is difficult to make an exact diagnosis of TP because of residual mass effect of the evacuated hematoma. Significance of mass effect caused by subdural air has been discussed in the literature only little. In this study, we found two new CT findings suggesting increased tension of subdural air. First, the subdural tensive air separates and compresses the frontal lobes. The compressed frontal lobes with widened interhemispheric space between the frontal poles mimic the silhouette of Mt. Fuji. We called this CT finding "Mt. Fuji" sign. The presence of air between the frontal poles associated with massive air over the frontal lobes presumably indicates an increased tension of the subdural air. "Mt. Fuji" sign was seen in 4 cases out of 5 TP cases. Another sign is the presence of multiple small air bubbles in the subarachnoid space, especially in the cisterns. We proposed that these air bubbles were trapped in the subarachnoid space through a tear of the arachnoid membrane which is caused by increased tension of air in the subdural space. This finding was present in 4 cases with TP. We emphasize that these two CT signs are helpful to make an accurate diagnosis of TP following surgery for chronic subdural hematoma.