Michihiko Osawa

Results of Direct Surgery for Aneurysmal Subarachnoid Haemorrhage: Outcome of 2055 Patients who Underwent Direct Aneurysm Surgery and Profile of Ruptured Intracranial Aneurysms

Summary Background and Purpose. The purpose of this study is to evaluate the therapeutic value of our surgical treatment of subarachnoid haemorrhage in a large series with standardized surgical principles. Methods. Results of 2055 direct operations on ruptured intracranial aneurysms, treated in our institutions, where surgical indications, instruments and techniques were standardized, between 1988 and 1998, were retrospectively evaluated and outcome of the patients was discussed; cases treated by intravascular procedures were excluded. Results. According to the evaluation at discharge, 1083 (52.7%) patients were excellent, 324 (15.8%) good and 223 (10.9%) fair. There were 160 (7.8%) patients of poor outcome and the remaining 265 (12.9%) died. There were no differences in the outcome between pre-operative Hunt & Kosnik grade I and II, Fisher Scale 1 and 2, anterior circulation aneurysms and posterior circulation aneurysms except those at and around the basilar bifurcation, men and women, and those clipped and not clipped. Conclusions. The factors related to poor outcomes were, age of 60 years or over, pre-operative Hunt & Kosnik grade II or more, Fisher Scale 3 or more, aneurysm size over 15 mm in diameter, and location at and around the basilar artery bifurcation. The results presented in this study show the status of our direct surgical management of subarachnoid haemorrhage in a large series with standardized surgical principles and procedures.

Risks of surgery for patients with unruptured intracranial aneurysms

BACKGROUND With the widespread use of less invasive imaging tools, such as magnetic resonance angiography and computed tomographic angiography, unruptured cerebral aneurysms are found much more often than in the past. This retrospective study was undertaken to determine the risk factors for surgical intervention in a patient with an unruptured intracranial aneurysm. METHODS Over a 5-year period, 1,558 patients with intracranial aneurysms underwent surgery at our center. Of these, 310 patients (20%) with unruptured aneurysms were included in this study. RESULTS Out of 310 patients with unruptured aneurysms, 292 (95%) had a favorable outcome, and only one patient (0.3%) with a giant vertebral artery aneurysm died. Aneurysm size larger than 15 mm and location of the aneurysm in the posterior circulation were independent risk factors associated with less favorable outcomes. Patients with a single aneurysm had a better outcome than did patients with multiple aneurysms. CONCLUSION Our results support the contention that surgical treatment of unruptured intracranial aneurysms carries a low risk of morbidity and mortality and may improve the outcome in patients harboring cerebral aneurysms by preventing the devastating effects of subarachnoid hemorrhage. Aneurysm size, location, and number were risk predictors for surgical morbidity in patients with unruptured aneurysms.

Surgical outcome for multiple intracranial aneurysms

SummaryThe surgical outcome of 221 cases with multiple intracranial aneurysms operated upon during the years 1988 to 1994 were reviewed. The patients were classified into three groups according to the locations of the aneurysms; group 1: multiple aneurysms located unilaterally in the anterior circulation only (147 cases); group 2: multiple aneurysms located bilaterally in the anterior circulation only (44 cases) and group 3: multiple aneurysms located in both anterior and posterior circulation or in the posterior circulation alone (30 cases). In 132 cases of group 1 (89.8%) all aneurysms were treated in one-stage operations. Twenty-eight patients from group 2 (63.6%) received partial treatment, where only the ruptured or the symptomatic aneurysms were treated. In 12 other cases from group 2 (27.3%) all multiple aneurysms were treated in two-stage operations. In group 3 patients, one-stage operations were performed in 18 cases (60%), while 9 patients (30%) received partial treatment only. Of the 221 multiple aneurysm cases, 162 (73.3%) presented with manifestations of subarachnoid haemorrhage (SAH). The remaining 59 multiple aneurysms cases (26.7%) presented with manifestations other than SAH (unruptured aneurysms). In the postoperative follow-up, of the 221 multiple aneurysms cases, 113 (51.1%) were free of neurological deficit (excellent), 48 cases (21.7%) were capable of leading an independent life (good), 32 cases (14.5%) were not independent and needed to be assisted (fair), and 28 patients (12.7%) died. These results were comparable to the results of patients with single aneurysms operated on during the same period.Based on our results, we recommend that whenever possible all multiple aneurysms should be treated in one-stage operations. In unruptured multiple aneurysm cases surgical management is the recommended treatment. In poor grade SAH patients or unruptured multiple aneurysms in old patients, two-stage operations or partial treatment of only the ruptured or the symptomatic aneurysms may be adopted.

Functional image of dynamic computed tomography in diagnostic and prognostic evaluation of ischemic stroke within the first 6 hours.

Background and Purpose It is important to make a diagnosis before a low-density area appears on computed tomography for appropriate management of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acute ischemic stroke. Methods Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in which functional images were obtained. These findings were compared with angiographic findings, follow-up computed tomography, and clinical outcome. Results The functional images were categorized into three groups: (1) cortical type: abnormalities on time to peak image and/or corrected mean transit time image involving mainly cortical structures (29 cases); (2) noncortical type: abnormalities on either or both images limited to noncortical structures (7 cases); and (3) normal type: no abnormalities on both images (11 cases). Cortical type as a diagnostic test for arterial trunk occlusion had a good sensitivity (100%), specificity (95%), and accuracy (98%). Infarction volume on follow-up computed tomography correlated with extension of prolonged time-to-peak area (r=.80, P < .01) and that of prolonged corrected mean transit time area (r=.81, P < .01). Cortical type was associated with significantly unfavorable outcome (P < .01). Conclusions Functional image of dynamic computed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be useful not only for indicating definitive angiography and subsequent therapy but for evaluating the effectiveness of surgical or medical recanalization.

Extradural extension of glioblastoma multiforme into the oral cavity: Case report

A rare case of glioblastoma multiforme with oral extension is presented in a 41-year-old female. She underwent two surgical treatments and both radiotherapy and chemotherapy for the right temporoparietal glioblastoma multiforme. A follow-up computed tomographic scan and magnetic resonance imaging demonstrated destruction of the temporal base and extradural extension of the tumor into the orbital, nasal, and oral cavities. This is the first report of the oral extension of glioblastoma multiforme. The mechanism for the extradural extension is discussed.

Newly designed bayonet clips for complicated aneurysms: technical note.

Three newly designed bayonet clips (crankshaft clips) are presented. They were designed to occlude aneurysms with irregular necks by using the angle and shank portion of a bayonet clip (shank clipping). The new clips have shorter distal blades and longer shanks (proximal blades), and the angle portions are bent to an angle of smaller degree. These clips are useful particularly for aneurysms located in a wider space.

Clinical Analysis of Internal Carotid Artery Aneurysms with Reference to Classification and Clipping Techniques

Summary An intraoperative classification of intradural internal carotid artery (ICA) aneurysms not related to the arterial division but based on their operative presentation and clipping techniques is introduced. On the basis of the surgeons view of the operative field via the pterional approach in 156 operated intradural ICA aneurysms in 143 patients, these aneurysms were classified according to their location in relation to the long axis of the ICA as either proximal, middle or distal in type and also according to their relation to the cross section of the ICA as either lateral, medial, ventral or dorsal in type. Numerically the largest in frequency is the middle type of aneurysm by axial location and the lateral type of aneurysms by cross sectional location. Eighty five percent of the lateral type aneurysms were at the arterial division. The majority of the large to giant aneurysms were of the ventral type and no dorsal type aneurysms were seen. About one third of the ICA aneurysms in this series were located free of the arterial division. All dorsal type aneurysms and most of the medial type aneurysms were not related to the arterial division. Clipping techniques were classified into perpendicular and parallel clipping, as to the direction of the clip-blades in relation to the carotid axis. The parallel clipping was further classified into forward clipping, in which a clip was applied from the distal side of the ICA, and reversed clipping, in which a clip was applied from the proximal side of the ICA. Most of the aneurysms located at the arterial division required the perpendicular clipping and those free of the arterial division required the parallel clipping. Furthermore, the forward clipping was useful for proximal type aneurysms and the reversed clipping for distal type aneurysms. For the middle type aneurysms clipping was performed bidirectionally. This classification includes all types of the ICA aneurysms located at any points along its long axis and on its cross section, and is useful for planning safe and exact clipping of the ICA aneurysms.

A newly designed attachment device of multipurpose frame for neuronavigator : technical note

SummaryA newly designed attachment device of the multipurpose head frame (Sugita) for Neuronavigator (Watanabe) is presented with an illustrative case of glioblastoma in an eloquent area. This has extended the usefulness of the neuronavigator for those who prefer and use the multipurpose head frame, while the requirements for keeping a stereotactic combination and the original concept of the multipurpose head frame, as well as that of the neuronavigator have been kept undisturbed.

Internal carotid-posterior communicating artery aneurysm associated with unusually short posterior communicating artery

We report two cases of a ruptured internal carotid-posterior communicating artery aneurysm in which the ipsilateral posterior communicating artery is short and the P1 and P2 segments of the posterior cerebral artery are long. Unique angiographic and operative findings are described. Vertebral angiography with carotid compression is recommended to diagnose this rare variation. Recognition of this variation is important to avoid an inadvertent occlusion of arteries behind the aneurysm at the time of clipping. Copyright 1999 Harcourt Publishers Ltd.

Relationship between Clinical and Endocrinological Features following Transsphenoidal Surgery for Acromegaly

Fourteen patients with acromegaly who had undergone transsphenoidal surgery were followed for 1 to 7 years (average, 4.3 years). Pre- and postoperative growth hormone (GH) levels, changes in the GH response to thyrotropin releasing hormone (TRH) tolerance testing, and the correlation between clinical improvement and postoperative GH and somatomedin-C levels were studied. Clinical improvement was assessed by scoring of the pre and postoperative symptoms. A significant correlation was found between the postoperative GH and somatomedin-C levels (p<0.01). All patients with postoperative somatomedin-C levels of less than 2 IU/ml, including one of the three patients whose postoperative GH levels were between 5 and 10 ng/ml, showed clinical improvement. Normal responses to TRH testing were rare and were poorly correlated with clinical improvement. These results suggest that somatomedin-C is more useful than GH in predicting clinical improvement following surgery for acromegaly.