Yoichi Watanabe

Intra-Arterial Fluorescence Angiography with Injection of Fluorescein Sodium from the Superficial Temporal Artery during Aneurysm Surgery: Technical Notes

Intra-arterial fluorescence angiography from a catheter inserted into the external carotid artery (ECA) via the superficial temporal artery (STA) allowed us to satisfactorily evaluate cerebral arterial and venous blood flow. We report this novel method that allowed for repeated angiography within minutes with a low risk of complications due to catheter placement from the STA. The STA was secured at the edge of the standard skin incision during cerebral aneurysm surgery. A 3 Fr catheter was inserted approximately 5 cm to 10 cm into the STA. After manual injection of 5 ml of 20 times diluted 10% fluorescein sodium (fluorescein), fluorescein reached the intracranial internal carotid artery (ICA) through the common carotid artery or anastomoses between the ECA and ICA. Fluorescence emission from the cerebral arteries, capillaries, and veins was clearly observed through the microscope and results were recorded. Quick dye clearance makes it possible to reexamine within 1 minute. In addition, we made a graph of the fluorescence emission intensity in the arteries, capillaries, and veins using fluorescence analysis software. With intravenous fluorescence angiography, dye remains in the vessels for a long time. When repeated examinations are necessary, intervals of approximately 10 minutes are required. There were some cases we could not correctly evaluate with intravenous injection due to weak fluorescence emission. Fluorescence angiography with intra-arterial injection from a catheter inserted into the carotid artery or another major vessel, like conventional angiography, has a risk of procedure-related complications. We report our new method since it solved these problems and is useful.

Development of and Clinical Experience with a Simple Device for Performing Intraoperative Fluorescein Fluorescence Cerebral Angiography: Technical Notes

To perform intraoperative fluorescence angiography (FAG) under a microscope without an integrated FAG function with reasonable cost and sufficient quality for evaluation, we made a small and easy to use device for fluorescein FAG (FAG filter). We investigated the practical use of this FAG filter during aneurysm surgery, revascularization surgery, and brain tumor surgery. The FAG filter consists of two types of filters: an excitatory filter and a barrier filter. The excitatory filter excludes all wavelengths except for blue light and the barrier filter passes long waves except for blue light. By adding this FAG filter to a microscope without an integrated FAG function, light from the microscope illuminating the surgical field becomes blue, which is blocked by the barrier filter. We put the FAG filter on the objective lens of the operating microscope correctly and fluorescein sodium was injected intravenously or intra-arterially. Fluorescence (green light) from vessels in the surgical field and the dyed tumor were clearly observed through the microscope and recorded by a memory device. This method was easy and could be performed in a short time (about 10 seconds). Blood flow of small vessels deep in the surgical field could be observed. Blood flow stagnation could be evaluated. However, images from this method were inferior to those obtained by currently commercially available microscopes with an integrated FAG function. In brain tumor surgery, a stained tumor on the brain surface could be observed using this method. FAG could be performed with a microscope without an integrated FAG function easily with only this FAG filter.

Intracranial hemorrhage and platelet transfusion after administration of anti-platelets agents: Fukushima Prefecture.

We conducted a case series study to assess intracerebral hemorrhage (ICH) in the context of anti-platelets agents (APAs) and platelet (PLT) transfusion in Fukushima Prefecture.This study included patients who were newly diagnosed with ICH between January 2008 and June 2014 in the neurosurgical hospitals of Fukushima Prefecture.　Four of ten neurosurgical hospitals responded to our questionnaire.　Of 287 ICH patients, 51 (20.6%) were on APA therapy, of whom PLT transfusion was given to only one persistently bleeding patient who was on dual anti-platelet therapy.　In a follow-up survey, 30 out of 51 ICH patients on APA therapy, average age 75 years, were analyzed, of whom 21 (70%) were male.　The predominant underlying disease was diabetes mellitus.　It is interesting to note that peripheral artery disease and aortic aneurysm were among the indications for APAs.　ICH was mainly observed supratentorially.　Hematoma enlargement was observed in 13 (44.8%) cases.　By day 7, 3 patients (10%) had died from complications of ICH.　In this study, we show that ICH during APA therapy matched what was observed in Kanagawa Prefecture.　Whether or not a national survey differs, we anticipate greater statistical validity and an opportunity to improve patient outcomes in Japan and around the world.

Intraoperative Fluorescence Cerebral Angiography by Laser Surgical Microscopy: Comparison With Xenon Microscopy and Simultaneous Observation of Cerebral Blood Flow and Surrounding Structures

BACKGROUND Laser surgical microscopes should enable uniform illumination of the operative field, and require less luminous energy compared with existing xenon surgical microscopes. OBJECTIVE To examine the utility of laser illumination in fluorescence cerebral angiography. METHODS Fluorescein sodium (fluorescein) was used as a fluorescent dye. We first compared the clarity of cerebral blood flow images collected by fluorescence angiography between the laser illumination and xenon illumination methods. We then assessed use of the laser illuminator for simultaneous observation of blood flow and surrounding structures during fluorescence angiography. Furthermore, the study was designed to evaluate usefulness of the thus determined excitation light in clinical cases. RESULTS Fluorescence angiography using blue light laser for excitation provided higher clarity and contrast blood flow images compared with using blue light generated from a xenon lamp. Further, illumination with excitation light consisting of a combination of 3 types of laser (higher level of blue light, no green light, and lower level of red light) enabled both blood flow and surrounding structures to be observed through the microscope directly by the surgeon. CONCLUSION Laser-illuminated fluorescence angiography provides high clarity and contrast images of cerebral blood flow. Further, a laser providing strong blue light and weak red light for excitation light enables simultaneous visual observation of fluorescent blood flow and surrounding structures by the surgeon using a surgical microscope. Overall, these data suggest that laser surgical microscopes are useful for both ordinary operative manipulations and fluorescence angiography.