Impact Of Indocyanine Green Video Angiography In Vascular Diseases Of Neurosurgery

Backgrounds:Indocyanine green(ICG) is a near-infrared dye with an absorption and emission peaks of 805 and 835nm, respectively. When administered by intravenous route, it combines with globulins and stays intravascular. A near-infrared digital camera allows us to observe the fluorescence of ICG in vessels. Lastly, the excretion of the ICG is accomplished by the liver. In 1967, the first application of fluorescence angiography in neurosurgery was carried out. With the appearance of the microscope integrated near-infrared indocyanine green video angiography (ICG VA), indocyanine green video angiography has been widely used in vascular diseases of neurosurgery.Objective:The purpose of this research is to evaluate the application of indocyanine green video angiography in vascular diseases of neurosurgery.Methods:Between September 2012 and September 2014,62 cases who accepted operative treatment in Qilu Hospital of Shandong University (including 41 intracranial aneurysms; 16 moyamoya diseases and 5 dural arteriovenous fistulas) were investigated and analyzed retrospectively. Indocyanine green video angiography was performed in all the operation procedures of the patients. For the aneurysm cases, CT was carried out on the first postoperative day to determine whether there was infarction. In addition, CTA or DSA was performed postoperatively to confirm the clipping of aneurysm. The results of the CTA or DSA were also compared with the images of ICG VA during operation. For the 16 moyamoya disease cases, CT was performed postoperatively to determine whether infarction had happened. Besides, the patients underwent CTA or DSA to evaluate the effect of vascular anastomosis. We made a comparison of the results of ICG and CTA or DSA as well. For the 5 patients with dural arteriovenous fistulas, DSA was performed to confirm the complete resection of the lesions and results of DSA and ICG were compared.Results:During the 41 clipping operations, aneurysmal neck remnant was found in 4 cases by the intraoperative indocyanine green video angiography. The operators made adjustments according to the images of ICG video angiography. No infarction happening in all the 41 cases was confirmed by the postoperative CT. Of the 41 patients,36 underwent postoperative CTA or DSA. Complete obliteration of aneurysms and parent vessels patency were confirmed by the CTA or DSA in 34 cases. The accordance of ICG video angiography and DSA (or CTA) was 94.4%. In two cases, the ICG video angiography showed complete clipping of the aneurysm. However the DSA discovered tiny aneurysmal neck remnants postoperatively. During the revascularization of the cerebral arteries of the 16 moyamoya disease cases, ICG video angiography indicated no stenosis of the anastomotic area and occlusion of the blood flow. Postoperative CTA or DSA confirmed patency of the anastomosis in 12 cases (Postoperative CTA or DSA was performed in 12 cases). The accordance was 100%. In one case, patency of the anastomosis was suggested by the DSA which was carried out 1 week after the operation. But occlusion was discovered by the DSA which was performed 6 months after the operation. For the 5 dural arteriovenous fistula patients, intraoperative ICG and postoperative DSA demonstrated the same results in all 5 cases, both showing the complete resection of the lesions. The accordance of them was 100%.Conclusion:Indocyanine green video angiography is conducive to the operations of the vascular diseases of neurosurgery. In aneurysm operations, ICG video angiography can clearly show the shape, size and location of the aneurysms and proximal and distal end of the parent arteries. After the clipping of the aneurysms, ICG video angiography can provide reliable assessment of aneurysm clipping as well as patency of the parent vessels. In moyamoya diseases operative procedures, ICG video angiography can confirm the effect of the bypass and the patency of the anastomotic area. In Dural arteriovenous fistula surgery, ICG video angiography not only can locate the lesions accurately and quickly before the resection, but also can confirm the complete removal of dural arteriovenous fistula after the resection. ICG video angiography is simple and easy to perform and can provide real-time information. In addition, its images are of high-quality and high accuracy with less cost. In the future, ICG video angiography may become a useful routine technique during operation of vascular diseases of neurosurgery.