Indocyanine green videoangiography “in negative”: definition and usefulness in spinal dural arteriovenous fistulae

Abstract

Purpose Indocyanine green videoangiography (IGV) has proven its effectiveness in the field of exovascular neurosurgery, both in the intracranial and spinal compartment, but is necessary to define a systematic process for the performance of the IGV to facilitate its interpretation during the procedure. We have defined and applied the concept of videoangiography ''in negative'' (INIGV) to spinal dural arteriovenous fistulae (dAVF) for the detection and treatment of arteriovenous shunts, so called because the first phase is performed with the vessel suggestive of being pathological occluded. Methods A Pentero-operating microscope with nearinfrared IGV-integrated system (Carl Zeiss Co., Germany) was used. At our institution, 24 patients were treated for a spinal dAVF between 1995 and 2011, only in the last 4 cases, INIGV was performed. Results We describe the IGV in negative procedure and show the most illustrative cases. In all cases, the fistula occlusion was confirmed by postoperative selective digital subtraction angiography (DSA). INIGV demonstrate its capacity in detecting vessels not actually arterialized that should be respected and avoid some of the main limitations of the conventional IGV. This is a technical description about an Indocyanine green (ICG) videoangiographic procedure modification that is superior to merely performing ICG before and after clipping of a dAVF. ConclusionThe INIGV results are rapid and easy to interpret procedure and provide great advantages to the dAVF treatment. Nevertheless, further studies are needed with a larger sample size to determine if INIGV may reduce the need to perform immediate postoperative DSA.

Indocyanine green videoangiography methodological variations: review

“…Regarding study design, 14 articles were retrospective series [8,20,21,25,37,42,46,57,58,60,69,74,75,83] and 4 case reports [5,31,61,84]. There were no randomized controlled trials or prospectives studies.…”

“…Three [26,39,63] of the remaining 21 articles contained duplicated patients, so only the report with the largest relevant cohort was included. A total of 18 studies [5,8,20,21,25,31,37,42,46,57,58,60,61,69,74,75,83,84] were included in this review.…”

“…Seven studies included ICGVA procedures with the peculiarity of the temporary clipping of the vessel to be analyzed [20,25,46,57,69,74,75]. This methodology was applied in different pathologies.…”

“…Among these 102 studies, 7 were not written in English and 4 were editorials, commentaries, and letters to the editor. In the remaining 91 articles, 13 involved oncologic pathology [14,15,22,24,36,47,49,55,62,66,71,81,84], 29 brain aneurysm [3, 5, 7, 8, 11-13, 16, 28-30, 38, 40, 43, 48, 50, 52, 54-57, 61, 63, 65, 67, 68, 70, 85, 90], 10 spinal arteriovenous fistula (AVF) or arteriovenous malformation (AVM) [33,35,45,51,53,59,64,75,80,86], 17 intracranial AVF or AVM [21, 23, 34, 37-39, 41, 44, 60, 72, 74-79, 82], 8 brain revascularization [1,20,31,69,73,83,88,91], and 14 miscellany [6, 9, 10, 18, 19, 25-27, 32, 46, 56, 58, 59, 89]. In the second phase, 65 studies were rejected from our review because they only included conventional ICGVA procedures.…”

“…As a result, all of the blood vessels blocked by a clot, atheroma, brain parenchyma, or calcifications and small diameter vessels like perforator arteries or thick wall of the vessels, as well as blind angles, are rendered invisible. Second, vascular filling with ICG follows an additive pattern, in which the arterial, capillary, and venous phases overlap [74,75]. In arteriography, the contrast filling pattern is sequential, with each phase replacing the previous one.…”