Value of Indocyanine Green Videoangiography in Deciding the Completeness of Cerebrovascular Surgery

OBJECTIVE: Recently, microscope-integrated near infrared indocyanine green videoangiography (ICG-VA) has been widely used in cerebrovascular surgery because it provides real-time high resolution images. In our study, we evaluate the efficacy of intraoperative ICG-VA during cerebrovascular surgery. METHODS: Between August 2011 and April 2012, 188 patients with cerebrovascular disease were surgically treated in our institution. We used ICG-VA in that operations with half of recommended dose (0.2 to 0.3 mg/kg). Postoperative digital subtraction angiography and computed tomography angiography was used to confirm anatomical results. RESULTS: Intraoperative ICG-VA demonstrated fully occluded aneurysm sack, no neck remnant, and without vessel compromise in 119 cases (93.7%) of 127 aneurysms. Eight clipping (6.3%) of 127 operations were identified as an incomplete aneurysm occlusion or compromising vessel after ICG-VA. In 41 (97.6%) of 42 patients after carotid endarterectomy, the results were the same as that of postoperative angiography with good patency. One case (5.9%) of 17 bypass surgeries was identified as a nonfunctioning anastomosis after ICG-VA, which could be revised successfully. In the two patients of arteriovenous malformation, ICG-VA was useful for find the superficial nature of the feeding arteries and draining veins. CONCLUSION: ICG-VA is simple and provides real-time information of the patency of vessels including very small perforators within the field of the microscope and has a lower rate of adverse reactions. However, ICG-VA is not a perfect method, and so a combination of monitoring tools assures the quality of cerebrovascular surgery.

Comparative Study of Angiography and Magnetic Resonance Image in Verifying Obliteration of Arteriovenous Malformation after Gamma Knife Radiosurgery

OBJECTIVE: The purpose of this study is that magnetic resonance(MR) imaging can substitute for conventional angiography in verifying obliteration of arteriovenous malformation(AVM) after Gamma Knife radiosurgery. METHODS: Among the patients of AVM treated with Gamma Knife between 1992 and 1997, all of 40 patients who had been followed up more than 2 years(range 24-101 months) had no AVM on follow-up MR images. Follow-up imaging was performed every 6 months or when clinically warranted. Conventional angiography was performed when the AVM was no longer seen on MR images. RESULTS: Among 40 patients who had shown total obliteration on MR images, thirty one patients(77.5%) showed complete obliteration of the lesion on angiography. However, subtotal obliteration was shown in five patients(12.5%) and partial obliteration in four patients(10.0%). CONCLUSION: The conventional angiography is absolutely needed for verifying obliteration of AVMs and to eliminate the misunderstanding of follow-up MR images.