Riki Tanaka

Dual-Image Videoangiography During Intracranial Microvascular Surgery

OBJECTIVE Indocyanine green videoangiography (ICG-VA) is a valuable tool to assess vessel and aneurysm patency during neurovascular surgical procedures. However, ICG-VA highlights vascular structures, which appear white over a black background. Anatomic relationships are sometimes difficult to understand at first glance. Dual-image videoangiography (DIVA) enables simultaneous visualization of light and near-infrared fluorescence images of ICG-VA. METHODS The DIVA system was mounted on an OPMI Pentero Flow 800 intraoperative microscope. DIVA was used during microsurgical procedures on 5 patients who were operated for aneurysm clipping and superficial temporal artery-middle cerebral artery bypass. RESULTS DIVA provides real-time simultaneous visualization of aneurysm and vessels and surrounding structures including brain, nerves, and surgical clips. Although visual contrast between vessels and background is higher with standard black-and-white imaging, DIVA makes it easier to understand anatomic relationships between intracranial structures. DIVA also provides better vision of the depth of field. CONCLUSIONS DIVA has the potential to become a widely used intraoperative tool to check patency of intracranial vessels. It should be considered as an adjunct to standard ICG-VA for better understanding of vascular anatomy in relation to surrounding structures and can have an impact on decision making during surgery.

Dural arteriovenous fistula of the craniocervical junction manifesting as cerebellar haemorrhage.

We report a rare case of dural arteriovenous fistula at the craniocervical junction manifesting as cerebellar haemorrhage, which posed a diagnostic challenge for physicians. A 77-year-old woman with no history of arterial hypertension presented to our Emergency Department with dizziness, and imaging studies revealed a small cerebellar haemorrhage. She was diagnosed with hypertensive intracerebral haemorrhage and conservatively treated. Four months later, she developed subarachnoid haemorrhage, and imaging studies revealed dural arteriovenous fistula at the left C1 dural sleeve. Disruption of a distended cerebellar vein due to venous hypertension by dural arteriovenous fistula was considered to be responsible for intracerebral haemorrhage and subarachnoid haemorrhage. Dural arteriovenous fistula was cured following surgical ligation of a feeding artery and a draining vein. The present case was educational in that effort to identify the cause of bleeding using vascular imaging studies may be important in patients with seemingly typical hypertensive intracerebral haemorrhage, particularly in those without a past history of arterial hypertension.

The outcomes of early aneurysm repair in World Federation of Neurosurgical Societies grade V subarachnoid haemorrhage patients with emphasis on those presenting with a Glasgow Coma Scale score of 3

Grade V subarachnoid haemorrhage (SAH) patients may be dichotomised into those with temporary deterioration and those with irreversible injury, and only the former have a chance of favourable outcomes by aneurysm obliteration. One method of differentiating the two conditions is to wait and observe potential recovery for 12-48hours. However, early rebleeding and non-convulsive seizures may occur during this period. In our institution, grade V SAH patients receive immediate treatment (general anaesthesia induction and aneurysm obliteration within 24hours of onset) to minimise those risks. We focused on therapeutic outcomes in SAH patients presenting with a Glasgow Coma Scale score of 3 (GCS-3). Between January 2006 and December 2013, 82 GCS-3 SAH patients were admitted, among whom 51 (62%) underwent immediate aneurysm obliteration. Their outcomes 90days after onset were evaluated with the Glasgow Outcome Scale, with either good recovery or moderate disability regarded as favourable outcomes. Multivariate logistic regression analysis was performed to identify variables correlated with favourable outcomes. Among the 51 patients, 11 (22%) had favourable 90-day outcomes. Age (odds ratio [OR], 0.838; 95% confidence interval [CI], 0.733-0.959; p=0.010) and intact pupillary light reflex (OR, 21.939; 95% CI, 1.465-328.576; p=0.025) were correlated with favourable outcomes. By contrast, neither intact respiratory pattern nor isocoric pupils was correlated with favourable outcomes. The current results indicate that vigorous intervention may be worth attempting in young GCS-3 SAH patients with intact pupillary light reflex. It remains unclear, however, whether the seemingly high frequency of favourable outcomes was truly due to reduction in early rebleeding or seizures.

Real-time patency verification during clipping aneurysm and STA-MCA by-pass with dual-image videoangiography

Abstract The dual-image videoangiography (DIVA) is a new tool which helps identify vessels and surrounding structure. This method is based on use of indocyanine green video angiography (ICG-VA) technology on real time microscopic operative image. In this two case, we report of using DIVA in STA-MCA bypass surgery of 46 years old, female patient of stenosis of right MCA. And using DIVA during clipping ICA paraclinod aneurysm of 35 years old, female. During surgery, it helped in identifying temporal and frontal branches of the STA and there careful selection. After anastomosis, DIVA was used to refine vessel patency and functioning of the anastomosis. DIVA has the potential to replace ICG-VA as a tool for checking the patency of graft during bypass procedures and obliteration of aneurysm along with surgical procedures for AVM and d-AVF. DIVA allows visualization of vessels against a background of normal brain and has better visualization at greater depth and high magnification. This is particularly important during bypass surgery, which very often is performed in deep surgical fields and high magnification.

Computational Fluid Dynamics Analysis and Correlation with Intraoperative Aneurysm Features

INTRODUCTION There are many controversies about computational fluid dynamics (CFD) findings and aneurysm initiation, growth, and ultimate rupture. The aim of our work was to analyze CFD data in a consecutive series of patients and to correlate them with intraoperative visual aneurysm findings. METHODS Hemoscope software (Amin, Ziosoft Corporation, Minato ward, Tokyo, Japan) was used to process images from 17 patients who underwent clipping of 18 aneurysms. Pressure (P), wall shear stress (WSS) gradient and vectors, normalized WSS, and streamlines (SL) direction and velocity were assessed. CFD data were compared to intraoperative visual findings. A total of 39 aneurysm wall areas were assessed. RESULTS Red, thin aneurysm wall areas were more often associated with low WSS. However, the association of low WSS with high P, diverging WSS vectors, direct impact of SL, and high SL velocity more frequently matched with yellow, atherosclerotic aneurysm walls. CONCLUSIONS Low WSS alone is not sufficient to determine the thickness of an aneurysm wall. Its association with other parameters might enable one to distinguish preoperatively atherosclerotic, thick areas (high P, diverging WSS vectors, high flow velocity) from thin areas with higher rupture risk (parallel WSS vectors, lower flow velocity). The changing balance between these parameters can modify the features and the risk of rupture of aneurysm wall over time.

Long term prognosis of ventriculoatrial shunt for idiopathic normal pressure hydrocephalus in the elderly

Abstract Objective: A retrospective study was conducted to access the long-term prognosis of inserting the Ventriculoatrial (VA) shunt in the elderly for the idiopathic normal pressure hydrocephalus (iNPH). Material and Methods: Retrospective data is collected from April 2004 to August 2015, and 1065 patients were selected. Patients who underwent surgical examination or surgery in suspected iNPH were included. Tap test is done in all cases and found to be effective for 968 cases and 656 VA shunts for 614 cases. Out of 614 cases there are 440 cases in which patient age were over 75 years. Of these 440 cases only 141 cases were able to observe 03 years or more after the surgery, 37 deaths and 05 cases with survival and unknown prognosis were found among them. So we analyzed this group mainly in 99 cases that the prognosis after 03 years was known. We access the outcome of VA shunt by the modified Rankin scale (mRS), iNPH grading scale (iNPHGS) and complications in the operative 656 cases and in 03 years follow up of 141 patients. Results: Of 141, there are 78 males and 63 females. Age at the time of VA shunt insertion was 81.5±4.1 years and age at final follow-up was 85.2±4.4 years. The proportion of patients who achieved a favorable outcome by complications was 97.9% in 03 years follow-up period and 87.7% in which follow-up is less than 03 years. At the time of VA shunt insertion out of 141, 57 patients lies between 75-79 years, 57 between 80-84, 24 between 85 to 89, and only 03 were found to be 90 years or more. At the time of final follow-up at 03 years, 15 patients lies between 75 to 79 years, 56 between 80 to 84 years, 57 between 85 to 89 years and 23 patents were found to be 90 years or greater. 70 cases or almost 50% exceeded 85 years. At the time of VA shunt 1, 11, 39, 51, 36, 3, 0 patients were in 0 to 6 modified Rankin Scale Score respectively and at 03 years follow-up 8, 19, 32, 29, 9, 2, 37 were in 0 to 6 mRS respectively. Comparison of the study is done with SIPHONI study on VP shunt and LP shunt. Conclusion: Patients suspected of having idiopathic normal pressure hydrocephalus were treated by VA shunt and found no significant difference in serious adverse effects. This study shows that VA shunt is an effective choice for iNPH in the late elderly population, but it needs more randomized control trial to establish its efficacy.

Study of predisposing risk factors and etiology of chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms – an institutional experience

Abstract Introduction: Chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms might lead to sudden neurological deterioration and may need emergency evacuation. We studied the effects of various factors in its etiology. Materials and methods: A retrospective study of 91operated clipped patients of unruptured aneurysms in the year 2014-2015 was taken. Various predisposing factors were studied. Results: Goreisan use was not associated with any reduction in post operative CSDH formation. Arachnoidoplasty and reduced post operative dead space contributed in a reduced formation of CSDH. Conclusion: Older male patients with aneurysms who had been treated with anticoagulant drugs should be considered candidates for additive ARP to prevent the development of postoperative CSDH.