Indocyanine Green Videoangiography Research Articles

Indocyanine Green Angiography in the Surgical Management of Cerebral Arteriovenous Malformations

Indocyanine green (ICG) angiography is commonly used to map the vascular configuration of cerebral arteriovenous malformations (AVMs) during resection. To determine whether ICG improves rates of resection and clinical outcomes. A retrospective chart review was done for all patients undergoing resection of an AVM by the senior author (R.F.S.) between 2007 and 2011. Operative reports, hospital records, and radiographic imaging were used to determine the use of ICG, the incidence of residual disease, and clinical outcomes. A total of 130 cases (56 ICG, 74 non-ICG) were identified. Average AVM grade (2.2 vs 2.4) and size (2.7 vs 2.7 cm) were similar between the ICG and non-ICG groups, respectively. ICG was more often used when the AVM nidus was close to the cortical surface (71.4% vs 17.6%; P = .001) or lobar (82.1% vs 54.1%; P = .008). Eighteen patients (13.8%) were noted to have residual disease. Reoperation rates and change in modified Rankin Scale score were not different between the 2 groups (12.5% vs 14.9%, P = .8; 0.6 vs 0.4, P = .17). There were no ICG-attributable complications. ICG videoangiography is a quick and safe method of intraoperatively mapping the angioarchitecture of superficial AVMs, but it is less helpful for deep-seated lesions. This modality alone does not improve the identification of residual disease or clinical outcomes. Surgeon experience with extensive study of preoperative vascular imaging is paramount to achieving acceptable clinical outcomes. Formal angiography remains the gold standard for the evaluation of AVM obliteration.

Abstract T MP36: Indocyanine Green Videoangiography for Assessment of Postoperative Hyperperfusion in Moyamoya Disease

Introduction: Postoperative cerebral hyperperfusion (HP) is a notable complication that occurs more frequently in moyamoya disease (MMD) than in atherosclerosis of unknown etiology. This study aimed to clarify the characteristics of intraoperative indocyanine green (ICG) videoangiography in MMD and atherosclerotic disease in terms of postoperative HP. Methods: This prospective study included 47 patients with 60 sides that underwent superior temporal artery (STA)-middle cerebral artery (MCA) single bypass. ICG videoangiography was performed after revascularization. The ICG time intensity curve was recorded in the STA, proximal MCA, distal MCA, and superficial Sylvian vein, and the angiographic differences among adult MMD, pediatric MMD, and atherosclerosis were analyzed. Results: Twenty two patients (27 sides) had adult MMD, 14 patients (22 sides) had pediatric MMD, and 11 patients (11 sides) had atherosclerosis. Postoperative HP was significantly higher in adult MMD (40.7%) than in pediatric MMD (18.2%) and atherosclerosis (0%). Adult MMD with HP was associated with a longer ICG peak time (P<0.001). There was no significant difference in ICG peak time among presentations in MMD, and no correlation between ICG peak time and preoperative hemodynamic parameters. The ratio of the vessel caliber was also higher in adult MMD with HP (P<0.001). Conclusions: ICG videoangiography provides different characteristics of bypass flow among adult MMD, pediatric MMD, and atherosclerosis. Poor distribution and run-off of blood flow from the STA might contribute to postoperative HP in MMD. The occurrence of postoperative HP in MMD could depend on two factors: host STA size and recipient MCA integrity.

Application of indocyanine green video angiography in parasagittal meningioma surgery

There are no doubts about the role that indocyanine green video angiography (ICGVA) can play in current vascular neurosurgery. Conversely, in brain tumor surgery, and particularly in meningioma surgery, this role is still unclear. Vein management is pivotal for approaching parasagittal meningiomas, because venous preservation is strictly connected to both extent of resection and clinical outcome. The authors present the technical traits and the postoperative outcome of the application of ICGVA in patients undergoing parasagittal meningioma surgery. The authors retrospectively collected demographic, radiological, intraoperative, and follow-up data in 43 patients with parasagittal meningiomas who underwent surgery with the assistance of ICGVA at Padua Neurosurgical Department between October 2010 and July 2013. Intraoperative ICGVA findings at different stages (before dural opening, after dural opening, during resection, after resection) were reviewed. Additional data on functional monitoring, temporary venous clipping, and flow measurements were also recorded. The overall postoperative outcome was evaluated by assessing both the extent of resection and the clinical outcome data. The ICGVA studies were performed 125 times in 43 patients, providing helpful data for vein management and tumor resection in all stages of surgery. In 16% of meningiomas completely occluding the superior sagittal sinus, the ICGVA data differed from radiological findings and changed the surgical approach. In 20% of cases the intraoperative ICGVA findings directly guided the surgical strategy: venous sacrifice was necessary in 7 cases, without postoperative consequences; temporary clipping with neurophysiological monitoring proved to be predictive of safe venous sacrifice. In 7% of cases the ICGVA data needed to be supplemented with flow measurements. Simpson Grade I-II and Grade III resections were achieved in 86% and 14% of cases, respectively, with a 4.6% rate of overall morbidity. This study shows that ICGVA can assist the different stages of parasagittal meningiomas surgery, guiding the vein management and tumor resection strategies with a favorable final clinical outcome. However, in the authors' experience the use of other complementary tools was mandatory in selected cases to preserve functional areas. Further studies are needed to confirm that the application of ICGVA in parasagittal meningioma surgery may improve the morbidity rate, as reported in this study.

Advances in Surgical Approaches to Dural Fistulas

Dural arteriovenous fistulas are abnormal connections of dural arteries to dural veins or venous sinuses originating from within the dural leaflets. They are usually located near or within the wall of a dural venous sinus that is frequently obstructed or stenosed. The dural fistula sac is contained within the dural leaflets, and drainage can be via a dural sinus or retrograde through cortical veins (leptomeningeal drainage). Dural arteriovenous fistulas can occur at any dural sinus but are found most frequently at the cavernous or transverse sinus. Leptomeningeal venous drainage can lead to venous hypertension and intracranial hemorrhage. The various treatment options include transarterial and transvenous embolization, stereotactic radiosurgery, and open surgery. Although many of the advances in dural arteriovenous fistula treatment have occurred in the endovascular arena, open microsurgical advances in the past decade have primarily been in the tools available to the surgeon. Improvements in microsurgical and skull base approaches have allowed surgeons to approach and obliterate fistulas with little or no retraction of the brain. Image-guided systems have also allowed better localization and more efficient approaches. A better understanding of the need to simply obliterate the venous drainage at the site of the fistula has eliminated the riskier resections of the past. Finally, the use of intraoperative angiography or indocyanine green videoangiography confirms the complete disconnection of fistula while the patient is still on the operating room table, preventing reoperation for residual fistulas.

Introduction: Evolving applications of fluorescence technology in neurosurgery

In this issue of Neurosurgical Focus, we will explore the exciting topic of fluorescence-guided surgery (FGS). Neurosurgeons have increasingly relied on FGS for the management of different cerebrovascular and neoplastic lesions. Fluorescence-guided surgery has been established in cerebrovascular neurosurgery with the use of indocyanine green (ICG) angiography. The use of 5–aminolevulinic acid (5-ALA) for fluorescence-guided resection of high-grade gliomas has been widely used around the world for more complete tumor resections. Other tumor types are currently being studied for the use of 5-ALA and FGS. Current regulatory barriers limiting the use of 5-ALA in the US have facilitated the study of other fluorescenceguided technologies for tumor resection. Fluorescein and other fluorophores have demonstrated their own advantages and limitations in the resection of high-grade gliomas. The following collection of papers will provide readers with the most recent information on currently available FGS technologies and the exciting emerging modalities that may advance FGS in neurosurgery. The leading article in this issue by Butte and colleagues reports on a new technology: near-infrared imaging of brain tumors using Tumor Paint BLZ-100. The accompanying editorial by Dr. Roberts further emphasizes the strengths and limitations of this emerging tool. The second article by Coburger and colleagues describes the correlation between 5-ALA intraoperative fluorescence and Gd-diethylenetriaminepentaacetic acid (Gd-DTPA)– enhanced intraoperative MRI findings for tumor detection at the borders of contrast-enhancing lesions. The subsequent article by Acerbi and colleagues reviews their experience with the use of FGS with fluorescein for resection of high-grade gliomas, and the corresponding editorial by Dr. Berger further elucidates the potential of this fluorophore, which does not carry the regulatory limitations imposed on 5-ALA. In a very different application, Roessler and colleagues review important details regarding intraoperative ICG videoangiography assessment for intracranial aneurysm surgery. Januszewski and colleagues describe flow-based evaluation for revascularization, while Marbacher and colleagues review a large series of fluorescence-guided resection of primary brain tumors and brain metastases. Millesi and colleagues discuss their experience with resection of spinal tumors. The other subsequent papers further review emerging applications of fluorescence technologies in neurosurgery. We are very pleased with this issue of Neuro­ surgical Focus and believe the readers will find it very informative. (http://thejns.org/doi/abs/10.3171/2013.12.FOCUS13582)

Essentials in intraoperative indocyanine green videoangiography assessment for intracranial aneurysm surgery: conclusions from 295 consecutively clipped aneurysms and review of the literature

Indocyanine green (ICG) videoangiography (VA) in cerebral aneurysm surgery allows confirmation of blood flow in parent, branching, and perforating vessels as well as assessment of remnant aneurysm parts after clip application. A retrospective analysis and review of the literature were conducted to determine the current essential advantages of ICG-VA in aneurysm surgery. The authors retrospectively evaluated all aneurysm cases treated with the aid of intraoperative ICG-VA at a single institution between 2007 and 2013. They also analyzed the literature published since the initial description of ICG-VA in 2003. Two hundred forty-six procedures were performed in 232 patients harboring 295 aneurysms. The patients, whose mean age was 54 years, consisted of 159 women and 73 men. One hundred twenty-four surgeries were performed after subarachnoid hemorrhage, and 122 were performed for incidental aneurysms. Single aneurysms were clipped in 185 patients, and multiple aneurysms were clipped in 47 (mean aneurysm diameter 6.9 mm, range 2-40 mm). No complications associated with ICG-VA occurred. Intraoperative microvascular Doppler ultrasonography was performed before ICG-VA in all patients, and postoperative digital subtraction angiography (DSA) studies were available in 121 patients (52.2%) for retrospective comparative analysis. In 22 (9%) of 246 procedures, the clip position was modified intraoperatively as a consequence of ICG-VA. Stenosis of the parent vessels (16 procedures) or occlusion of the perforators (6 procedures), not detected by micro-Doppler ultrasonography, were the most common problems demonstrated on ICG-VA. In another 11 procedures (4.5%), residual perfusion of the aneurysm was observed and one or more additional clips were applied. Vessel stenosis or a compromised perforating artery occurred independent of aneurysm location and was about equally common in middle cerebral artery and anterior communicating artery aneurysms. In 2 procedures (0.8%), aneurysm puncture revealed residual blood flow within the lesion, which had not been detected by the ICG-VA. In the postoperative DSA studies, unexpected small (< 2 mm) aneurysm neck remnants, which had not been detected on intraoperative ICG-VA, were found in 11 (9.1%) of 121 patients. However, these remnants remained without consequence except in 1 patient with a 6-mm residual aneurysm dome, which was subsequently embolized with coils. In a large cohort of consecutive patients, ICG-VA proved to be a helpful intraoperative tool and led to a significant intraoperative clip modification rate of 15%. However, small, < 2-mm-wide neck remnants and a 6-mm residual aneurysm were missed by intraoperative ICG-VA in up to 10% of patients. Results in this study confirm that DSA is indispensable for postoperative quality assessment in complex aneurysm surgery.

Flow-based evaluation of cerebral revascularization using near-infrared indocyanine green videoangiography

Indocyanine green (ICG) videoangiography has been established as a noninvasive technique to gauge the patency of a bypass graft; however, intraoperative graft patency may not always correlate with graft flow. Altered flow through the bypass graft may directly cause delayed graft occlusion. Here, the authors report on 3 types of flow that were observed through cerebral revascularization procedures. Between February 2009 and September 2013, 48 bypass procedures were performed. Excluded from analysis were those cases in which ICG videoangiography was not performed during surgery (whether it was not available or there was a technical issue with the microscope or the quality of ICG angiography) and/or in which angiography or CT angiography was not done within 24-72 hours after surgery. After anastomosis, bypass patency was assessed first using a noninvasive technique and then with ICG videoangiography, and flow through the graft was characterized. Patients who received a vein or radial artery graft were also evaluated with intraoperative angiography. Thirty-three patients eligible for analysis were retrospectively analyzed. The patients had undergone extracranial-intracranial (EC-IC) or IC-IC bypass for ischemic stroke (13 patients), moyamoya disease (10 patients), and complex aneurysms (10 patients; 6 giant or large aneurysms, 2 carotid blister-like aneurysms, and 2 dissecting posterior inferior cerebellar artery [PICA] aneurysms). Thirty-six bypasses were performed including 26 superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses (2 bilateral and 1 double-barrel), 6 EC-IC vein grafts, 1 EC-IC radial artery graft, 1 PICA-PICA bypass, 1 MCA-posterior cerebral artery bypass, and 1 occipital artery-PICA bypass. Robust anterograde flow (Type I) was noted in 31 grafts (86%). Delayed but patent graft enhancement and anterograde flow (Type II) was observed in 4 cases (11%); 1 of these cases with an EC-IC vein graft degraded gradually to very delayed flow with no continuity to the bypass site (Type III). Additionally, 1 STA-MCA bypass graft revealed no convincing flow (Type III). The 5 patients with Type II or III grafts were evaluated with a flow probe and reexploration of the bypass site, and in all cases the reason the graft became occluded was believed to be recipient-vessel competitive flow. In no case was there evidence of stenosis or a technical issue at the site of the anastomosis. Three patients with Type II and the 1 patient with Type III flow (11% of procedures) did not have a patent bypass on postoperative imaging. Indocyanine green videoangiography is reliable for evaluating flow through the EC-IC or IC-IC bypass. The type of flow observed through the graft has a direct relationship with postoperative imaging findings. Despite the possibility of competitive flow, Type III and some Type II flows through the graft indicate the need for graft evaluation and anastomosis exploration.

Target-controlled infusion technique with indocyanine green videoangiography for radial artery graft

ObjectTo understand the relationship between the parent artery and its distal arteries, blood vessels running through the subarachnoid space need to be extensively dissected, which is time-consuming. We examined the efficacy of temporary clipping with the indocyanine green (ICG) technique (target-controlled infusion (TCI) technique), in which the parent artery is occluded using a temporary clip, and ICGV (videoangiography) is performed to clarify the relationship between the distal M4 and proximal M2. MethodsThirteen radial artery grafts (RAGs) for internal carotid aneurysm underwent TCI to confirm the relationship between M2 and cortical M4. To monitor the perfusion pressure of the cortical middle cerebral artery, superficial temporal artery (STA) to M4 anastomosis was performed before RA-M2 anastomosis. We performed anastomosis of the recipient of STA- M4 that was distal and downstream of the M2 segment that is the recipient of RA-M2 anastomosis. To select the proper recipient M4 of the STA-M4 anastomosis, the ICGV image range was set sufficiently wide to accommodate the possibility that the distal artery was not the one anticipated. ICGV followed complete occlusion by temporary clipping of the recipient M2. ResultsIn 2 of the 13 cases, the relationship between the M2 and M4 could not be clarified. ConclusionsIn cases with developed collateral circulation or small perfusion area of the occluded M2, it was difficult to ascertain the relationship by TCI. Nevertheless, TCI was useful in 11 of the 13 cases, suggesting that unnecessary dissection in the subarachnoid space may be reduced using this technique.

Identification of plaque location using indocyanine green videoangiography during carotid endarterectomy.

The aim of the present study was to assess whether surgical microscope-based indocyanine green (ICG) videoangiography (ICG-VA) using FLOW 800 software provides useful evaluation of blood flow during carotid endarterectomy (CEA). Twenty CEA procedures were performed in 19 patients between July 2011 and January 2012. ICG was injected intravenously before and after CEA, and ICG-VA video sequences were analyzed using FLOW 800. Regions of interest were identified in the common carotid artery, plaque, internal carotid artery, and external carotid artery, and changes in intensity values were evaluated. The distal and proximal ends of the carotid plaque were identified in 87.5 and 75 % of cases, respectively. After CEA, intensity values in the common carotid artery, plaque, internal carotid artery, and external carotid artery had increased by 162 ± 129, 337 ± 212, 139 ± 151, and 177 ± 143, respectively. The intensity values in the region of the plaque showed the greatest improvement. ICG-VA can provide information regarding plaque location vessel patency during CEA. FLOW 800 software provides semiquantitative information regarding blood flow, especially in cases of severe stenosis with collapse of the internal carotid artery.

Selective Targeted Cerebral Revascularization via Microscope Integrated Indocyanine Green Videoangiography Technology.

Protective or flow replacement bypass surgery has an important role in the management of complex middle cerebral artery (MCA) aneurysms. Protective bypass is useful when prolonged temporary arterial occlusion is needed for clip reconstruction. Flow replacement bypass is instead important when aneurysmal trapping is the treatment of choice in order to supply permanent collateral blood flow to the brain distal to the "trapped" vessel. In both cases, the identification of the correct recipient artery is an essential surgical step. When a superficial (cortical) artery is chosen as recipient, it indeed has to represent a distal branch of the involved (temporarily or permanently occluded) vessel.Here we describe a technique for selective-targeted revascularization based on the use of indocyanine green video angiography (ICG-VA), a microscope-integrated intraoperative tool nowadays known to provide real-time assessment of the cerebral circulation with distinct visualization of arterial, capillary and venous angiographic phases. The technique is founded on the analysis of differences in the timing of filling of M4 vessels seen on serial ICG-VAs. It enables reliable identification of the cortical recipient and eliminates the risk of erroneous revascularization of non-involved territories. The surgical decision-making of two patients treated for complex MCA aneurysms with selective-targeted bypass is presented.

Flow assessment application “Flow-Insight”の脳血管撮影への臨床応用

Flow assessments by indocyanine green videoangiography (ICG-VA) has become common to evaluate cerebral blood flow during vascular surgery. In order to obtain detailed flow information, we have developed a new software named “Flow-Insight” based on the principle of perfusion image processing. In this study, we applied “Flow-Insight” to digital subtraction angiography (DSA) to investigate arrival time (AT), blood volume (BV) and mean transit time (MTT) during endovascular surgery. “Flow-Insight” imported serial DSA data in DICOM format, and calculated integration of a time-intensity curve over time in each pixel for quantitative analysis. We predicted a thrombotic problem by observing delayed BV in a case with an unruptured aneurysm. In addition, several parameters from this application might be reliable predictors, critical alarms and treatment prognosis for endovascular surgery.

The clinical diagnosis and treatment of blood-blister-like cerebral aneurysms in supra-clinoid segment of internal carotid artery

To study the clinical characteristics, surgical principles and treatment options of blood-blister-like cerebral aneurysms in supra-clinoid segment of internal carotid artery. Twelve blood-blister-like aneurysms were retrospectively studied including 4 open-surgery cases and 8 endovascular-treated cases from November 2008 to December 2012. Patients comprised 8 female and 4 male patients, whose mean age was 46.6 (range 38-56) years. Eleven patients presented with severe headache as the primary symptom, and 1 patient was found with aneurysm incidentally. Preoperative Hunt-Hess graded 0 in 1 patient, graded I in 5 patients, graded II in 4 patients, and graded III in 2 patients. By DSA examinations, 4 blood-blister-like aneurysms located in anterior wall and 8 in medial-anterior wall of supra-clinoid segment of internal carotid artery. Open surgical treatment included direct clipping, trapping, or wrapping and interventional treatment included stent-assisted coiling or simple stent placement. Intra-operative electroencephalogram and somatosensory evoked potentials monitoring was regularly used. Microvascular Doppler ultrasonography and indocyanine green videoangiography were used to assess blood flow in parent and branch vessels. The patients were followed up at 6 months by CT angiography (CTA) examination in outpatient clinic. For 4 open surgeries, 2 aneurysms were directly clipped, 1 was trapped and 1 was wrapped. The patient underwent trapping paralyzed postoperatively. For endovascular treatment, 6 patients were coiled assisted with stents and 2 patients were treated with simple stent placement. All the patients were followed with a mean follow-up time of 16 months (range, 6-61 months). At 6 months follow-up, 3 out of 4 surgical treated patients had good outcome and 1 was moderately severe disabled by modified Rankin scale; 1 patient underwent wrapping recurred and was transferred to endovascular treatment. Of the 6 patients treated with stent-assisted coiling, 4 patients were recurrent and coil replacements were performed. Two patients with simple stent placement had no recurrences. Blood-blister-like aneurysm is a special type of complex cerebral aneurysm. Comprehensive understanding of blood-blister-like aneurysm is the key to successful treatment.Open surgery is difficult procedure with high risk and complications while stent-assisted coiling has a high recurrent rate. To date, neither is the safe and effective treatment option.

Progress in the treatment of unruptured aneurysms.

Recent technological progress has reduced the complication rate of unruptured aneurysm. We treated 128 unruptured aneurysms between April 2006 and March 2012. Seventy-six aneurysms (59 %) were clipped and 52 (41 %) were coil embolized. After 2010, we applied new instruments, i.e., near-infrared indocyanine-green videoangiography (ICG), an intraoperative endoscope, preoperative detailed MRI, and a stent-assisted coil embolization. In the results: (1) In 60 aneurysms treated before 2009, three patients showed a deterioration of more than two points in mRS (5 %). In 68 aneurysms treated after 2010, no patients showed deterioration (0 %) (p: n.s.). (2) No patients died and 126 patients (98 %) were discharged to home directly. (3) No patients showed rupture after treatment. In conclusion, the appropriate selection of treatment and recent technological progress have facilitated sophisticated treatment of unruptured aneurysms. Recently, the complication rate in surgery and endovascular surgery for unruptured aneurysms has become acceptably low.

穿通枝温存の観点からみた脳動脈瘤クリッピング術の手術手技

A devastating complication after surgical clipping for intracranial aneurysms is neurological deficits caused by blood flow insufficiency of perforating arteries. To preserve blood flow of perforators, surgeons must identify all perforators around aneurysms. When a perforator adheres to aneurysmal walls, it should be dissected from the aneurysms as far as possible. When a perforator originates at an aneurysmal neck or dome, a clip must be placed with shaping the origin of the perforator. After clipping, the patency of perforators are confirmed by Doppler ultrasonography, indocyanine green (ICG) videoangiography and motor-evoked potential (MEP) monitoring. The above-mentioned meticulous surgical maneuver can minimize the risk of cerebral infarction due to the occlusion of perforators and improve surgical outcomes after aneurysmal clipping.

Indocyanine Green for Vessel Identification and Preservation Before Dural Opening for Parasagittal Lesions

The purpose of this video series is to document how indocyanine green (ICG) videography can be used before dural opening to help identify and preserve potentially critical draining veins into the sagittal sinus during resection of parasagittal lesions. For both patients, a craniotomy was performed in close juxtaposition to the sagittal sinus. ICG (0.25-mg/kg dose) was administered intravenously just before dural opening. Using a microscope equipped with fluorescent filters, real-time flow assessment of the underlying veins was done. The identified veins were marked on the dural surface. Dural opening was made by dissecting around these vessels. After tumor resection, ICG was re-administered, and videoangiography was conducted to confirm vascular integrity. We document the application of ICG videoangiography using 3-dimensional video recording for 2 cases of parasagittal meningiomas. We present first a 61-year-old woman with motor seizures on the right side and a tumor volume of 48.32 mL. The second patient is a 30-year-old woman with right leg weakness and a tumor volume of 16.96 mL. The information provided by this technology changed the surgical procedure. ICG angiography could be divided into arterial, capillary, and venous phases comparable to what is seen in digital subtraction cerebral angiography. This tool not only helps identify critical draining veins that could be injured during dural opening, but also demonstrated vascular integrity after lesion removal. The ICG administration and videoangiography during and after parasagittal tumor resection can be used to avoid vascular damage in neurosurgery.

Clinical values of intraoperative indocyanine green fluorescence video angiography with Flow 800 software in cerebrovascular surgery

Background Microscope-integrated near-infrared indocyanine green video angiography (ICG-VA) has been used in neurosurgery for a decade. This study aimed to assess the value of intraoperative indocyanine green (ICG) video angiography with Flow 800 software in cerebrovascular surgery and to discover its hemodynamic features and changes of cerebrovascular diseases during surgery. Methods A total of 87 patients who received ICG-VA during various surgical procedures were enrolled in this study. Among them, 45 cases were cerebral aneurysms, 25 were cerebral arteriovenous malformations (AVMs), and 17 were moyamoya disease (MMD). A surgical microscope integrating an infrared fluorescence module was used to confirm the residual aneurysms and blocking of perforating arteries in aneurysms. Feeder arteries, draining veins, and normal cortical vessels were identified by the time delay color mode of Flow 800 software. Hemodynamic parameters were recorded. All data were analyzed by SPSS version 18.0 (SPSS Inc., USA). T-test was used to analyze the hemodynamic features of AVMs and MMDs, the influence on peripheral cortex after resection in AVMs, and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in MMDs. Results The visual delay map obtained by Flow 800 software had more advantages than the traditional playback mode in identifying the feeder arteries, draining veins, and their relations to normal cortex vessels. The maximum fluorescence intensity (MFI) and the slope of ICG fluorescence curve of feeder arteries and draining veins were higher than normal peripheral vessels (MFI: 584.24±85.86 vs. 382.94±91.50, slope: 144.95±38.08 vs. 69.20±13.08, P &lt;0.05). The arteriovenous transit time in AVM was significantly shorter than in normal cortical vessels ((0.60±0.27) vs. (2.08±1.42) seconds, P &lt;0.05). After resection of AVM, the slope of artery in the cortex increased, which reflected the increased cerebral flow. In patients with MMD, after STA-MCA bypass, cortex perfusion of corresponding branches region increased and local cycle time became shorter. Conclusion Intraoperative ICG video angiography combined with hemodynamic parameter analysis obtained by Flow 800 software appears to be useful for intraoperative monitoring of regional cerebral blood flow in cerebrovascular disease.

Prospective Evaluation of the Interest of Indocyanine Green Video-Angiography Applied During Unruptured Intracranial Aneurysm Clipping

La sciatique par hernie discale est une pathologie rachidienne fréquente dont le pronostic semble moins favorable que précédemment décrit et pour laquelle de nombreuses zones d’ombre persistent. Cette radiculalgie résulte de la conjonction d’une hernie discale à proximité de la racine nerveuse et du développement d’une inflammation locale dont on ne connaît pas le processus exact. Le traitement est en général non chirurgical, mais il n’y a pas de consensus sur son contenu en raison du faible nombre d’essais randomisés. Plusieurs traitements dits « peu invasifs » sont disponibles mais aucun n’a fait ses preuves. Lorsque l’évolution est défavorable, le traitement chirurgical est supérieur au traitement conservateur dans les mois qui suivent l’intervention. Cet avantage s’atténuant avec le temps, il est actuellement recommandé d’informer consciencieusement chaque patient des avantages et des inconvénients de chaque option afin de choisir le traitement le mieux adapté.Sciatica is a frequent spinal condition with a clinical course worse than previously described and for which many gray areas persist. This radiculopathy is due to a combination of a herniated disc near the nerve root and the development of a local inflammation, for which we do not know the exact pathophysiology. Treatment is generally non surgical, however, due to the paucity of randomized trials, no universal recommendations are available. Several minimally invasive techniques have been developed but none has proven its efficacy. In case of unfavorable clinical evolution, surgery is superior to conservative treatment over several months but this difference decreases over time. Thus, shared decision-making process is recommended in order to choose the optimal treatment for each patient.

Advantage of Microscope Integrated for Both Indocyanine Green and Fluorescein Videoangiography on Aneurysmal Surgery: Case Report

Neck clipping of a large middle cerebral artery aneurysm was performed using a newly developed surgical microscope integrated with modules for both indocyanine green (ICG) and fluorescein videoangiography. During surgery, ICG and fluorescein videoangiography by intra-arterial or intravenous injection were safely carried out without interrupting the surgical procedure. Based on the findings obtained from the case, we evaluated the differences between the dyes and the injection routes. With intra-arterial injection, fluorescein offered sharper contrast images and was better at depicting fine arteries than ICG. Patchy staining of vessel walls was observed in intravenous fluorescein videoangiography, while it was not evident in ICG. Intra-arterial injection method had a great advantage in the rapid clearance of the dyes, which allowed us to perform repeated videoangiography within a short period, and was useful in detecting incomplete clipping in this case; however, catheter insertion requires additional work and carries a potential risk. Use of a microscope integrated for both ICG and fluorescein videoangiography would be another method for repeated evaluation. Namely, alternate use of the dyes enables us to perform videoangiography in a short time even via intravenous injection.

Use of indocyanine green videoangiography during intracranial aneurysm surgery reduces the incidence of postoperative ischaemic complications

Microscope-integrated near-infrared indocyanine green videoangiography (ICGVA) has been shown to be a useful adjunct for intracranial aneurysm surgery. That the routine application of this technique reduces the risk of postoperative ischaemic complication, however, has not been reported. We present a retrospective matched-pair comparison of ICGVA guided aneurysm surgery versus historic control surgical cohort treated by the same author. Index patients and controls were matched for aneurysm size, location, patient demographics, risk factors, comorbidities, and surgical treatments. Ninety-one eligible patients with 100 intracranial aneurysms were treated using ICGVA assistance. There were no statistically significant differences between the two groups in terms of patient age, sex, risk factors, comorbidities and aneurysm characteristics. Of the 100 aneurysms in the ICGVA group, 107 investigations of ICGVA were performed. In 79 aneurysms (79.0%), ICGVA was considered useful but did not affect surgical management. In six patients (6.0%), ICGVA led to a crucial change of intraoperative strategies. In nine patients (9.0%), it was considered critical in assuring patency of small perforators. ICGVA was of no benefit in four patients (4.0%) and was misleading in two (2.0%). Postoperative ischaemic complications occurred in three patients (3.3%) in the ICGVA group compared with seven patients (7.7%) in the control group (p<0.001). Our study supports the use of ICGVA in aneurysm surgery as a safe and effective modality of intraoperative blood flow assessment. With all limitations of a retrospective matched-pair comparison, the use of ICGVA during routine aneurysm surgery reduces the incidence of postoperative ischaemic complications.

The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy

Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery. Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment.