Comparison between Digital Subtraction Angiography and Indocyanine Green Video Angiography in the Operative Management of Aneurysmal Subarachnoid Hemorrhage

Abstract

Background Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a “pre-contrast image” or mask from subsequent images, once the contrast medium has been introduced into a structure, hence the term “Digital subtraction angiography.” Indocyanine green video angiography (ICG-VA) is a safe and practical method of real-time delineation of microvasculature used in the surgical management of intracranial aneurysms, arteriovenous malformations, and other vascular lesions. Intraoperative ICG-VA is used as an adjunct in addition to intraoperative or postoperative DSA, and in other cases, it is used as the sole method to confirm the complete obliteration of clipped intracranial aneurysm. The only limitation of ICG-VA is the nonvisibility of vessels that are not in the operative field. Intraoperative ICG is useful in the clipping of intracranial aneurysms to ensure a gross patency of branch vessels; however, the presence of residual aneurysms and subtle changes in flow in branch vessels is best seen by DSA. Methods ICG angiography was done during the surgery and the findings of intraoperative ICG angiography were compared with postoperative DSA that was done between 6 and 12 weeks. DSA was done to see any compromise of lumen of parent vessel by clip, any residual aneurysm. Results In our study, intraoperative ICG complete aneurysm obliteration was present in all 30 (100%) patients, while in postoperative DSA complete aneurysm obliteration was diagnosed in 27 (90.0%) patients. Parent vessel patency was present in all 30 (100.0%) patients in both intraoperative ICG-VA and postoperative DSA. In intraoperative ICG distal branch patency was present in 26 (86.7%) patients, while in postoperative DSA distal branch patency was diagnosed in 27 (90.0%) patients. Conclusion We compared the intraoperative ICG finding and postoperative DSA finding and found that DSA is more sensitive than ICG in depicting residual aneurysm neck, hence reducing the risk of rupture of the aneurysm in future. Intraoperative ICG has high special resolution reflex feedback, intraoperative repositioning time is less and thus critical ischemia time is reduced. In a developing country like ours where DSA facilities are limited, ICG can be optimal investigation to delineate the vascular anatomy and confirmation of clip position thus reducing mortality.

Utilizing indocyanine green video angiography to bridge intracranial aneurysm treatment gaps in low- and middle-income countries: a mini-review

“…For example, a study conducted in the Department of Neurosurgery at the Sher-I-Kashmir Institute of Medical Sciences, India, has suggested that DSA may still have an advantage over ICG-VA in detecting residual aneurysm necks and reducing the risk of rupture in the future. 21 Despite this limitation, the authors pointed out that ICG-VA can be an optimal investigation for delineating vascular anatomy and confirming clip position, which can reduce mortality in LMICs where DSA facilities are limited. 21 Overall, the current application of ICG-VA in LMICs for IA surgery is a promising avenue for improving patient outcomes and reducing the need for more invasive and expensive postoperative imaging techniques.…”

“…21 Despite this limitation, the authors pointed out that ICG-VA can be an optimal investigation for delineating vascular anatomy and confirming clip position, which can reduce mortality in LMICs where DSA facilities are limited. 21 Overall, the current application of ICG-VA in LMICs for IA surgery is a promising avenue for improving patient outcomes and reducing the need for more invasive and expensive postoperative imaging techniques.…”

“…6 Consequently, intraoperative repositioning time is reduced, leading to decreased critical ischaemia duration and a shorter overall surgical duration. 21 While alternatives like endovascular treatment exist, they are less prevalent in LMICs due to cost and knowledge constraints. 22 Implementing ICG-VA could potentially bridge this gap, as evidenced by studies from various LMICs.…”

“… 21 Despite this limitation, the authors pointed out that ICG-VA can be an optimal investigation for delineating vascular anatomy and confirming clip position, which can reduce mortality in LMICs where DSA facilities are limited. 21 …”

“… 6 Consequently, intraoperative repositioning time is reduced, leading to decreased critical ischaemia duration and a shorter overall surgical duration. 21 …”