Shuei Imizu

Clinical characteristics and risk factors of chronic subdural haematoma associated with clipping of unruptured cerebral aneurysms

Chronic subdural haematoma (CSDH) is an uncommon but potentially serious complication of clipping unruptured cerebral aneurysms. We conducted a study to identify the patients who are at risk of developing postoperative CSDH. The data from 713 consecutive patients who underwent clipping of unruptured anterior circulation aneurysms were reviewed, and risk factors correlated with CSDH were identified by multivariate regression analysis of demographic variables. Fifteen patients (2.1%) developed CSDH after the surgery. Advanced age (odds ratio [OR] 1.151, 95% confidence interval [CI] 1.051-1.261) and male gender (OR 3.167, 95% CI 1.028-9.751) were correlated with CSDH. Subsequently, all 713 patients were quadrichotomized on the basis of gender and age, with 70 years as the cut-off value for age. The frequency of CSDH in men <70 years of age was 1.3% and that in men ≥70 years of age was 15.1%, with risk of CSDH was significantly higher in the older men (OR 13.39; 95% CI: 3.42-52.44). The frequency of CSDH in women <70 years of age was 0.6% and that in women ≥70 years of age was 3.7%. As in men, the risk of CSDH was significantly higher in the older women (OR 6.69, 95% CI 1.10-40.73). The interval between the aneurysm clipping and CSDH development was 0.5-6 months, suggesting that clinical observation should be continued up to 6 months after surgery. Although prognosis for patients with a postoperative CSDH complication is generally favourable, the risk of CSDH should be taken into account when considering elective clipping of unruptured aneurysms in patients ≥70 years of age.

Decompressive Hemicraniectomy for Malignant Hemispheric Stroke in the Elderly: Comparison of Outcomes between Individuals 61-70 and .70 Years of Age

BACKGROUND Malignant hemispheric infarction is a life-threatening condition with a high mortality rate. Decompressive hemicraniectomy (DHC) is frequently a life-saving procedure that has shown the highest grade of evidence for patients 18 to 60 years of age. However, the efficacy of DHC in patients>60 years of age has rarely been investigated. METHODS A retrospective study was conducted in a single academic institution. Surrogates of patients with clinical signs of impending brain herniation despite standard medical therapy were offered the option of DHC regardless of age or the side of the lesion. The clinical data from 18 patients>60 years of age who underwent DHC for malignant hemispheric infarction in our institution were analyzed. Patients were classified into the following 2 groups: 61-70 and >70 years of age, and their demographics and surgical outcomes were compared. The variables compared included the male:female ratio, side of the lesion, type of stroke, site of vascular occlusion, use of thrombolytic therapy, National Institutes of Health Stroke Scale score, stroke onset-to-DHC interval, duration of hospital stay, infectious complications, and 90-day mortality rate. RESULTS There were no significant intergroup differences in any of the demographic variables evaluated. However, the 30-day mortality rate was significantly higher in the group that was >70 years of age (0% v 60%; P=.01) than in the group that was 61 to 70 years of age. CONCLUSIONS We suggest that the efficacy of DHC in malignant hemispheric stroke patients between 61 and 70 years of age be further investigated in future randomized trials. By contrast, it appears unlikely that patients>70 years of age would benefit from DHC.

Usefulness of a simplified management scheme for paraclinoid aneurysms based on a modified classification

Background: Our objective was to set up a management-oriented classification for paraclinoid aneurysms, and then design and apply a simplified management scheme according to each group defined by this classification. Methods: Paraclinoid aneurysms were classified as group I (supraophthalmic artery), group II (ophthalmic artery) and group III (infraophthalmic artery) aneurysms intradurally. Between January 2005 and December 2006, 86 cases with 89 paraclinoid aneurysms were treated. There were 35 (40.2%) aneurysms in group I (20 in group Ia, 15 in group Ib), 32 (36.8%) in group II and 20 (23%) in group III. Results: In group I aneurysms, 20 (57.1%) were treated by clipping or/and wrapping, while 15 (42.9%) were managed by coiling. In group II aneurysms, 20 (62.5%) were treated by clipping and 12 (37.5%) by coiling. The contralateral approach was performed for 4 (6%) aneurysms in groups I and II. All 20 group III aneurysms were treated by coiling. The overall rate of permanent complications was 4.6%. The rate of complete occlusion was 92.5% in surgical cases and 55.6% in endovascular ones. The overall outcomes in the treatment of paraclinoid aneurysms were excellent (GOS = 5, 95.4%). Conclusion: Based on our modified classification of paraclinoid aneurysms, a simplified management scheme was designed and applied. For group I (supraophthalmic artery) and group II (ophthalmic artery) aneurysms, surgical clipping or/and wrapping should be the first choice of treatment, while for group III (infraophthalmic artery) aneurysms, endovascular coiling should be the best modality. Additionally, individualizing the treatment planning might contribute to better results.

Recent advances in diagnostic approaches for sub-arachnoid hemorrhage

Sub-arachnoid hemorrhage (SAH) has been easily one of the most debilitating neurosurgical entities as far as stroke related case mortality and morbidity rates are concerned. To date, it has case fatality rates ranging from 32-67%. Advances in the diagnostic accuracy of the available imaging methods have contributed significantly in reducing morbidity associated with this deadly disease. We currently have computed tomography angiography (CTA), magnetic resonance angiography (MRA) and the digital subtraction angiography (DSA) including three dimensional DSA as the mainstay diagnostic techniques. The non-invasive angiography in the form of CTA and MRA has evolved in the last decade as rapid, easily available, and economical means of diagnosing the cause of SAH. The role of three dimensional computed tomography angiography (3D-CTA) in management of aneurysms has been fairly acknowledged in the past. There have been numerous articles in the literature regarding its potential threat to the conventional “gold standard” DSA. The most recent addition has been the introduction of the fourth dimension to the established 3D-CT angiography (4D-CTA). At many centers, DSA is still treated as the first choice of investigation. Although, CT angiography still has some limitations, it can provide an unmatched multi-directional view of the aneurysmal morphology and its surroundings including relations with the skull base and blood vessels. We study the recent advances in the diagnostic approaches to SAH with special emphasis on 3D-CTA and 4D-CTA as the upcoming technologies.

Voxel-based correlation between whole-brain CT perfusion with 320-row area detector ct and iodine 123 iodoamphetamine brain perfusion spect in patients with cerebrovascular disease.

Objective We compared cerebral blood flow (CBF) measured using computed tomographic (CT) perfusion (CTP) and N-isopropyl-p-[(123) I]-iodoamphetamine cerebral perfusion single-photon emission computed tomography (SPECT). Methods We used a 320-row area detector CT and N-isopropyl-p-[(123) I]-iodoamphetamine cerebral perfusion SPECT under similar conditions in patients with chronic cerebrovascular disease. Images were automatically aligned 3-dimensionally for voxel-by-voxel comparisons. Results Linear positive correlations were observed between CTP-CBF including high-blood-flow areas and SPECT-CBF over the whole brain (r = 0.001–0.6, P < 0.01), superior cerebral level (r = 0.45–0.93, P < 0.01), basal ganglia level (r = 0.44–0.77, P < 0.01), and skull base (r = 0.02–0.66, P < 0.01). Correlations between CTP-CBF excluding high-blood-flow areas were significantly higher (P < 0.0001). Conclusions Computed tomographic perfusion overestimated CBF compared with SPECT and showed poor correlation at the skull base. Computed tomographic perfusion CTP excluding high-blood-flow areas improved the correlation over the whole brain in patients with chronic cerebrovascular disease.

Contralateral approach to unruptured superior hypophyseal artery aneurysms.

OBJECTIVE To evaluate the feasibility and limitations of the contralateral approach to unruptured superior hypophyseal artery (SHA) aneurysms. METHODS Data regarding eight cases of superior hypophyseal artery aneurysms operated on by a contralateral pterional approach at our center from January 2008 to September 2010 were collected and evaluated retrospectively. Of these eight cases, six were male and two were female. The mean age was 57.1 years (range 28 years to 77 years). All the aneurysms were unruptured; five were on right side and three were on left side. The surgical technique and outcome of patients were reviewed. RESULTS All aneurysms were successfully clipped without complication and patency of all superior hypophyseal arteries was preserved. Postoperative three-dimensional computed tomography angiography revealed residual aneurysm in only one case. None of the patients had deterioration of visual acuity or field after surgery. The contralateral pterional approach was found to be appropriate for fully exposing the aneurysmal dome and neck without retraction of the optic nerve or the carotid artery in five cases. Slight retraction of the optic nerve was required in two cases, and significant manipulation of the optic nerve was required in one case. CONCLUSIONS The contralateral pterional approach for clipping of unruptured superior hypophyseal artery aneurysms is technically feasible and safe in a select group of patients where optimal results can be achieved without significant retraction of near by neurovascular structures.

Report on the international primary neurosurgical life support course in the eighth asian congress of neurological surgeons in Kuala Lumpur, Malaysia

On November 22, 2010, a simulation-based hands-on education course for medical staff in the neurosurgical fields was held in 8th Asian Congress of Neurological Surgeons (ACNS) in Kuala Lumpur, Malaysia. The present education course called Primary Neurosurgical Life Support (PNLS) course had been started by the Japan Society of Neurosurgical Emergency since 2008. This report summarizes the international version of PNLS course in 8th ACNS.

Surgical Treatment of Patients with Ischemic Stroke Decompressive Craniectomy

A number of patients with ischemic cerebrovascular stroke suffer a progressive deterioration secondary to massive cerebral ischemia, edema, and increased intracranial pressure (ICP). The evolution is often fatal. Stroke is the second – leading cause of death worldwide. Life-threatening, complete middle cerebral artery (MCA) infarction occurs in up to 10% of all stroke patients, and this may be characterized as massive hemispheric or malignant space – occupying supratentorial infarcts. Malignant, space – occupying supratentorial ischemic stroke is characterized by mortality up to 80%, several reports indicated a beneficial effect of hemicraniectomy in this situation, converting the closed, rigid cranial vault into a semi open. The main cause of death encountered in these patients is severe postischemic brain edema leading to raised intracranial pressure, clinical deterioration, coma and death. The result is dramatic decrease in ICP and a reversal of the clinical and radiological signs of herniation. For these reasons, decompressive craniectomy has been increasingly proposed as a lifesaving measure in patients with large, space-occupying hemispheric infarction. Recent successes with intra-venous and intra-arterial thrombolytic therapy have resulted in an increased awareness of stroke as a medical emergency. Thus, increasing numbers of patients are being evaluated in the early hours following the ictal event. In the process of gaining more experience in the early management of patients with acute ischemic stroke, it has become clear that in a number of these patients a progressive and often fatal deterioration secondary to mass effect from the edematous, infarcted tissue occurs. An increasing body of experimental and clinical evidence suggests that some of these patients may benefit from undergoing a decompressive craniectomy. But, the timing and indications for this potential lifesaving procedure are still debated. The objectives of this chapter are; • To help better define the selection criteria for performing the surgery in case of supratentorial infarctions, • To assess the immediate outcome in terms of time conscious recovery and survival • To assess long term outcome and quality of life, using standard and functional assessment scales Complications have been reported in the literature when hemicraniectomy has been completed after cerebral infarction. Malignant cerebral ischemia occurs in a significant number of patients who undergo emergency evaluation for ischemic stroke. This patient