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Interruption of the fistulous point is the goal of treatment of spinal dural arteriovenous fistulas (dAVFs). Microsurgery remains a highly efficient treatment in terms of complete occlusion with the lowest risk of recurrence rate. It is reported that the hardest step involves finding the fistulous site itself, potentially extending surgical access and time and increasing potential postoperative surgical-related complications. The accurate preoperative detection of the shunt and spinal level together is crucial for guiding optimal, fast, and safe microsurgical treatment. We describe a preoperative angiographic protocol for achieving a safe and simple resection of spinal dural arteriovenous fistulas based on a 6-year institutional experience of 42 patients who underwent minimally invasive procedures. Two illustrative cases are included to support the technical descriptions. The suspected artery associated with the vascular malformation of interest is studied in our angiographic protocol through nonsubtracted selective acquisitions in lateral projection. The resulting frames are reconstructed with three-dimensional rotational angiography. The implementation of the preoperative angiographic protocol allowed 100% of intraoperative identification of the fistulous point in all cases with the use of a minimally invasive approach. Nowadays, neurosurgeons advocate for minimally invasive procedures and procedures with low morbidity risk for treatment of spinal dural arteriovenous fistulas. Our preoperative approach for accurate angiographic localization of the fistulous point through nonsubtracted and three-dimensional reconstructed angiography allowed us to achieve safe and definitive occlusion of the shunt. [ABSTRACT FROM AUTHOR]

Background: Despite advancements in endovascular techniques, microsurgical treatment for posterior circulation aneurysms remains challenging. Method: This report highlights the successful clipping surgery of a 17-year-old female patient with an aneurysm located at the basilar artery (BA) bifurcation and left anterior choroidal artery (AChoA). To improve exposure, the posterior communicating artery was transected. A straight fenestrated clip was then placed to repair the BA bifurcation aneurysm, followed by a curved mini clip for the AChoA aneurysm. Conclusion: This report demonstrates the nuances of microsurgery in the treatment of select complex cases, which can benefit from microsurgery to achieve optimal treatment outcomes. [ABSTRACT FROM AUTHOR]

Spinal dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular lesions. Diagnostic tools include pre- and postoperative digital subtraction angiography (DSA) and intraoperative indocyanine green videoangiography (ICG-VA). ICG-VA has a high predictive value in DI-AVF occlusion, but postoperative DSA remains a core component of postoperative protocols. The aim of this study was to evaluate the potential cost reduction of forgoing postoperative DSA after microsurgical occlusion of DI-AVFs. Cohort-based cost effectiveness study of all DI-AVFs within a prospective, single-center cerebrovascular registry from January 1, 2017, to December 31, 2021. Complete data including intraoperative ICG-VA and costs were available for 11 patients. Mean (SD) age was 61.5 (14.8) years. All DI-AVFs were treated with microsurgical clip ligation of the draining vein. ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 6 patients and confirmed complete obliteration. Mean (SD) cost contributions for DSA and ICG-VA were $11,418 ($4,861) and $12 ($2), respectively. Mean (SD) total costs were $63,543 ($15,742) and $53,369 ($27,609) for patients who did and did not undergo postoperative DSA, respectively. Comorbidity status was identified as the main driver of total cost (P = 0.01 after adjusting for postoperative DSA status). ICG-VA is a powerful diagnostic tool in demonstrating microsurgical cure of DI-AVFs, with a negative predictive value of 100%. Eliminating postoperative DSA in patients with confirmed DI-AVF obliteration on ICG-VA may yield substantial cost savings, in addition to sparing patients the risk and inconvenience of a potentially unnecessary invasive procedure. [ABSTRACT FROM AUTHOR]

Purpose: Despite being rarely reported, ischemic insults resulting from compromising small brainstem perforators following microvascular decompression (MVD) remain a potential devastating complication. To avoid this complication, we have been using indocyanine green (ICG) angiography intraoperatively to check the flow within the small brainstem perforators. We aim to evaluate the safety and usefulness of ICG videoangiography in MVD. Methods: We extracted retrospective data of patients who received ICG videoangiography from our prospectively maintained database for microvascular decompression. We noted relevant data including demographics, offending vessels, operative technique, outcome, and complications. Results: Out of the 438 patients, 15 patients with a mean age (SD) of 53 ± 10.5 years underwent intraoperative ICG angiography. Male:female was 1:1.14. The mean disease duration prior to surgery was 7.7 ± 5.3 years. The mean follow-up (SD) was 50.7 ± 42.0 months. In 14 patients, the offending vessel was an artery, and in one patient, a vein. Intraoperative readjustment of the Teflon pledget or sling was required in 20% (3/15) of the cases. No patient had any sort of brainstem ischemia. Eighty percent of the patients (12/15) experienced complete resolution of the spasms. 86.7% (13/15) of the patients reported a satisfactory outcome with marked improvement of the spasms. Three patients experienced slight hearing affection after surgery, which improved in two patients later. There was no facial or lower cranial nerve affection. Conclusion: Intraoperative ICG is a safe tool for evaluating the flow within the brain stem perforators and avoiding brainstem ischemia in MVD for hemifacial spasm. [ABSTRACT FROM AUTHOR]

Background: Both indocyanine green videoangiography (ICG-VA) and flowmetry were considered beneficial in preventing parent artery compromise during aneurysm surgery. However, the appropriate strategy that should be used remains controversial. The objective of the study is to assess the outcomes of aneurysm clipping through flowmetry or ICG-VA monitoring. Materials and Methods: This retrospective cohort study included 75 patients who underwent aneurysm clipping with vascular patency monitoring. In total, 42 patients underwent flowmetry monitoring and 33 ICG-VA monitoring. Preoperative disease severity and functional outcomes were assessed using the World Federation of Neurosurgical Societies (WFNS) grading system and the modified Rankin scale, respectively. Results: As compared with ICG-VA, flowmetry group had nonsignificant higher incidence of clip modification (31.7% vs. 18.2%, P = 0.29) and residual neck (22% vs. 10%, P = 0.218). Besides Fisher grade, flowmetry monitoring (Crude odds ratio [OR] = 0124, P = 0.015), young age, and anterior communicating artery location were the independent risk factors for vasospasm based on multivariate analysis. The incidence of parent artery compromise did not differ between both groups. Old age, poor preoperative WFNS grade, low Glasgow coma scale (GCS) score, left-side location, and long hospital stay were associated with poor functional outcomes in the univariate analysis. However, only the GCS score was considered a prognostic factor in the multivariate analysis (Adjusted OR = 0.03, P = 0.034). Conclusion: Both monitoring methods have similar functional outcomes. Although not influencing outcome, the flowmetry group has a higher incidence of angiographic vasospasm than the ICG-VA group. The vessel preparation for flowmetry monitoring is more complicated than that for ICG-VA; thus, we recommend ICG-VA for routine monitoring. Flowmetry may be applicable in distal aneurysms when hemodynamic insufficiency in a parent artery is suspected.

Background: Both indocyanine green videoangiography (ICG-VA) and flowmetry were considered beneficial in preventing parent artery compromise during aneurysm surgery. However, the appropriate strategy that should be used remains controversial. The objective of the study is to assess the outcomes of aneurysm clipping through flowmetry or ICG-VA monitoring. Materials and Methods: This retrospective cohort study included 75 patients who underwent aneurysm clipping with vascular patency monitoring. In total, 42 patients underwent flowmetry monitoring and 33 ICG-VA monitoring. Preoperative disease severity and functional outcomes were assessed using the World Federation of Neurosurgical Societies (WFNS) grading system and the modified Rankin scale, respectively. Results: As compared with ICG-VA, flowmetry group had nonsignificant higher incidence of clip modification (31.7% vs. 18.2%, P = 0.29) and residual neck (22% vs. 10%, P = 0.218). Besides Fisher grade, flowmetry monitoring (Crude odds ratio [OR] = 0124, P = 0.015), young age, and anterior communicating artery location were the independent risk factors for vasospasm based on multivariate analysis. The incidence of parent artery compromise did not differ between both groups. Old age, poor preoperative WFNS grade, low Glasgow coma scale (GCS) score, left-side location, and long hospital stay were associated with poor functional outcomes in the univariate analysis. However, only the GCS score was considered a prognostic factor in the multivariate analysis (Adjusted OR = 0.03, P = 0.034). Conclusion: Both monitoring methods have similar functional outcomes. Although not influencing outcome, the flowmetry group has a higher incidence of angiographic vasospasm than the ICG-VA group. The vessel preparation for flowmetry monitoring is more complicated than that for ICG-VA; thus, we recommend ICG-VA for routine monitoring. Flowmetry may be applicable in distal aneurysms when hemodynamic insufficiency in a parent artery is suspected. [ABSTRACT FROM AUTHOR]

Background and Study Aims Aneurysm clips must have adequate closing forces because residual blood flow in clipped aneurysms may result in aneurysm recurrence. Such flow can be intraoperatively detected by visual inspection, microvascular Doppler sonography, indocyanine green videoangiography (ICG-V), angiography, and puncture. Patients We present two patients with ruptured very small middle cerebral artery aneurysms (3 and 2.9 mm). The necks of both aneurysms were microsurgically clipped with Yasargil aneurysm clips without any complications. Results In both aneurysms, visual inspection suggested complete occlusion, but ICG-V showed persistent residual blood flow between the middle parts of the clip blades. The first patient was treated with a 5.4-mm FT744T clip (closing force of 1.47 N). After the ICG-V finding, a second 3.9-mm FT714T clip (closing force of 1.08 N) was placed on the tips of the already implanted clip to increase the closing forces. Subsequent ICG-V did not show any further residual blood flow. In the second patient, the aneurysm was clipped with an 8.0-mm FE764K clip (closing force of 1.77 N). Intraoperative ICG-V showed persistent residual blood flow within the aneurysmal dome despite complete closure of the clip. The clip was repositioned closer to the parent vessel. Consecutive ICG-V did not show any residual blood flow. Conclusion Visually undetected incomplete aneurysm occlusion can be revealed with ICG-V. In very small aneurysms, standard closing forces of clips may not be sufficient and complete closure of the clip branches should be intraoperatively validated with ICG-V. [ABSTRACT FROM AUTHOR]

Background: The surgical resection of the middle third parasagittal meningioma (PSM) is difficult, where the challenge is to systematically protect the eloquent parenchyma and collateral venous drainage. Method: We report a case of PSM that eroded the skull, wholly occluded the superior sagittal sinus at the middle third segment, underwent radical resection with evaluation and preservation of the collateral venous drainage by preoperative venography, and intraoperative indocyanine green videoangiography (ICGVA) that aimed to avoid postoperative complications. Conclusion: This case demonstrates the importance of venous preservation strategy and the value of ICGVA in the intraoperative assessment of collateral venous drainage function. [ABSTRACT FROM AUTHOR]

Background: Craniotomy is required for the removal of brainstem cavernous malformations (CMs) with repeated hemorrhage, and this condition is often complicated by an accompanying developmental venous anomaly (DVA). However, a DVA of the brainstem or cerebellum with drainage penetrating the pons is an exceptional finding., Observations: A 57-year-old man presented with double vision. Computed tomography revealed progressive enlargement of the hemorrhage in the dorsal pons. Contrast-enhanced magnetic resonance angiography revealed an expanded transverse vessel penetrating the center of the pons in contact with the CM. Digital subtraction angiography revealed that the DVA, comprising the expanded transpontine vein and some cerebellar medullary veins acting as normal venous drainage, coexisted with the CM. By utilizing the angioarchitecture and intraoperative neuronavigation system data, electrophysiological mapping, and indocyanine green videoangiography, complete removal of the CM was accomplished while preserving the DVA and brain function., Lessons: This study presents the intraoperative images of an expanded transpontine vein as a DVA, which has never been depicted in a live patient before, accompanied by a CM in the dorsal portion of the pons. https://thejns.org/doi/10.3171/CASE24314.

Fluorescein sodium (FNa) videoangiography (VA) was performed to evaluate blood flow within vessels and exclusion of the aneurysm after surgical clipping of intracranial aneurysms. The aim of this study was to report results of FNa-VA in a case series, including benefits and limitations of the technique, and compare intraoperative findings with postoperative cerebral angiography to assess reliability of FNa-VA. The study included 64 aneurysms in 50 consecutive patients. Following clip ligation of the aneurysm, 100 mg of FNa was administered intravenously. The microscope light was switched to the FL560 integrated fluorescence module. Aneurysm sac, parent arteries, and perforating arteries were observed. FNa-VA promoted real-time assessment of the surgical field in three-dimensional view through the binoculars with good image quality. In 79.68% of aneurysms, FNa-VA confirmed satisfactory clip application, as FNa did not penetrate into the aneurysm. In 14.06% of aneurysms, a homogeneous yellow-green color change occurred, which was accepted as a false-positive sign. In 6.25% of aneurysms, FNa seeped into the aneurysm emitting a heterogeneous green signal, which slowly dispersed throughout the sac. Postoperative angiography revealed satisfactory results. Small neck remnants were present in 5 patients, and mild parent artery stenosis was found in 3 patients. No ischemic event occurred secondary to parent artery or perforating artery occlusion. FNa-VA adds greatly to the safety of surgical treatment of intracranial aneurysms, particularly in lesions situated in deep locations, by enabling real-time inspection, which facilitates safer manipulation and evaluation of structures in question. [ABSTRACT FROM AUTHOR]

Background: Intraoperative indocyanine green videoangiography (ICG-VA) has been reported to be utilized in various cerebrovascular surgeries, wherein the blood flow is noticeably shown in white with a black background. ICG flow alone, but not other structures, can be observed using ICG-VA. We developed a novel high-resolution intraoperative imaging system using laser light source for simultaneously visualizing both visible light and near-infrared (NIR) fluorescence images of ICG-VA. Methods: We used a novel system for 14 cerebrovascular cases. The operative field was illuminated via an operating microscope using a novel laser light source with four bands at 464 (blue), 532 (green), 640 (red), and 785 nm (NIR region). The observed light from the operative field was split using a beam splitter cube into visible (420– 660 nm) and NIR fluorescence emission light (832–900 nm). Images from the color video and NIR fluorescence emission windows were merged for visualization on a monitor screen simultaneously. Laser light was compared with xenon light, and both setups were tested for cerebrovascular surgeries. Results: Laser light has numerous advantages over xenon light. The present setup clearly visualized the color operative field with enhanced blood flow. Complete clipping or incomplete clipping with neck remnant or remnant flow into an aneurysm was confirmed in aneurysm surgeries. Feeding arteries and draining veins were easily distinguished in case of arteriovenous malformation. Conclusions: Using the present setup, we can observe the color operative field and enhanced blood flow using ICG in real time. This setup could facilitate various cerebrovascular surgeries.

This study aimed to evaluate the safety and completeness of using intraoperative indocyanine green videoangiography (ICGV) combined with intraoperative angiography (IOA) for aneurysm clipping in a hybrid operating room (hOR). All patients who underwent microsurgical clipping in the hOR were identified from prospectively maintained neurosurgical databases. Medical charts and operative videos with ICGV and IOA were reviewed to determine the adequacy of clipping, and clinical and angiographic outcomes were retrospectively analyzed. Fifty-four cerebral aneurysms (ruptured, 31; unruptured, 23) in 50 patients (mean age, 59.4 ± 10.9 y; M:F, 22:28) were evaluated with ICGV and IOA during clipping. Additional IOA led to a clip adjustment during surgery in 9/54 (16.7%) aneurysms for which ICGV had been initially performed. Post-clip perforator compromise occurred in two (3.7%) cases, with a patient with an unruptured aneurysm experiencing permanent injury (grade 3 hemiparesis) and patient with a ruptured aneurysm experiencing transient deficit. Post-clip parent vessel stenosis occurred in one (1.9%) case; however, an ischemic event did not occur because the flow patency was identified by IOA. No other patients with unruptured aneurysms developed new neurologic deficits at discharge. Favorable outcomes (Glasgow Outcome Score [GOS], 4 or 5) were observed in 26/31 patients with ruptured aneurysms. Five patients had unfavorable outcomes (GOS, 2 or 3) from the initial insult. Post-treatment angiography within 1 week showed complete occlusion in 52 (96.3%) aneurysms and minor remnants in two (3.7%) aneurysms. Using combined ICGV and IOA in a hOR may improve the safety and completeness of microsurgical aneurysm clipping. [ABSTRACT FROM AUTHOR]

Indocyanine green videoangiography (ICG-VA) is a near-infrared range fluorescent marker used for intraoperative real-time assessment of flow in cerebrovascular surgery. Given its high spatial and temporal resolution, ICG-VA has been widely established as a useful technique to perform a qualitative analysis of the graft patency during revascularization procedures. In addition, this fluorescent modality can also provide valuable qualitative and quantitative information regarding the cerebral blood flow within the bypass graft and in the territories supplied. Digital subtraction angiography (DSA) is considered to be the gold standard diagnostic modality for postoperative bypass graft patency assessment. However, this technique is time and labor intensive and an expensive interventional procedure. In contrast, ICG-VA can be performed intraoperatively with no significant addition to the total operative time and, when used correctly, can accurately show acute occlusion. Such time-sensitive ischemic injury detection is critical for flow reestablishment through direct surgical management. In addition, ICG has an excellent safety profile, with few adverse events reported in the literature. This review outlines the chemical behavior, technical aspects, and clinical implications of this tool as an intraoperative adjunct in revascularization procedures.

Background Indocyanine green videoangiography (ICG-V) is used with increasing frequency in neurovascular surgery. ICG-V use in spinal dural arteriovenous fistulas (DAVFs) allows visualization of the hemodynamics of the fistula and to confirm its exclusion after ligation of the feeder. Here, we illustrate how ICG-V is useful for centering the surgical exposure during mini-invasive approaches to spinal DAVFs. Methods An overweight 66-year-old woman with progressive paraparesis and sphincter disturbances underwent treatment for a spinal DAVF fed by the left T6 radicular artery. After intraoperative fluoroscopy, T6 hemilaminectomy was performed. Because of slight misplacement of the bone opening, the feeder was not visible at the dural opening. We placed a temporary clip on a perimedullary arterialized vein and performed ICG-V while removing the clip. Results Reviewing the video clip and analyzing the direction of ICG flow inside the perimedullary venous plexus allowed us to locate the fistula with respect to the bone window and to extend the laminectomy in the correct direction. Conclusions IGC-V can be helpful in mini-invasive approaches to spinal DAVFs to recalibrate the bone opening after misplacement of the initial hemilaminectomy. [ABSTRACT FROM AUTHOR]

Abstract Background A compromised free flap perfusion attributable to vascular occlusion requires immediate operative correction. Indocyanine green (ICG) videoangiography may reduce the risk of partial skin flap necrosis in high-risk free flaps in patients undergoing head and neck reconstruction. The purpose of this study was to determine the role of ICG in cases of venous congestion in a rat model. Methods A standardized epigastric flap was raised and repositioned in 35 rats. Full venous occlusion of the draining superficial inferior epigastric vein was temporarily applied for 4, 5, 6, or 7 hours. Blood flow measurements including simultaneous laser-Doppler flowmetry and tissue spectrophotometry (oxygen-to-see [O2C]) and ICG videoangiography with the FLOW 800 tool were performed before flap raising, after temporary venous stasis, and after clinical monitoring for 1 week. The Youden index computed from the receiver operating characteristic curve was used to define an optimal cutoff value for necrosis prediction after 4 and 6 hours of stasis. Results The ICG videoangiography with the FLOW 800 tool was found to be superior to O2C in the prediction of flap necrosis. The accuracy of prediction was moderate after an interval of 4 hours of stasis (area under the curve [AUC] = 0.661; 95% confidence interval [CI]: 0.489–0.834) and good after 6 hours of stasis (AUC = 0.787; 95% CI: 0.65–0.915). Conclusions The O2C does not reliably predict tissue necrosis in cases of venous congestion. ICG videoangiography is a valuable tool that can predict clinical outcome and provide guidance on whether to salvage a congested flap.

Background: In surgical treatment of acute subdural hematoma (ASDH), neurosurgeons frequently encounter bleeding from cortical arteries, which is usually controlled with bipolar coagulation. However, bipolar coagulation is associated with a risk of sacrificing the cortical artery, which may affect the prognosis of neurological symptoms when these cortical arteries supply critical areas. In this article, we describe microsurgical repair of damaged cortical arteries using a 10-0 nylon micro-suture in patients with arterial-origin ASDH.Methods: After removal of the subdural hematoma, the exact bleeding point of the cortical artery was identified, and the 10-0 nylon suture stitches were placed on the arterial tear under a microscope. After completion of the micro-suture, vascular patency was confirmed by indocyanine green (ICG) videoangiography.Results: From June 2015 through February 2017, microsurgical repair was performed for seven cortical arteries in six patients. All damaged arteries were located near the Sylvian fissure, and all tears were pinhole tears. The average blood flow occlusion time was 8 min (range, 0-15 min). The patency of all seven repaired arteries was successfully confirmed by ICG videoangiography. Postoperative cerebral infarction was not observed except in one patient with cerebral contusion and a history of severe head trauma.Conclusions: The present report demonstrates that repair of a cortical artery by the 10-0 nylon micro-suture is a simple and safe method with a low risk of sacrificing the artery. This technique may be a good option in the surgical treatment of arterial-origin ASDH, especially when the accompanying cerebral contusion is minimal. [ABSTRACT FROM AUTHOR]

During the last 10 years, microscope-integrated indocyanine green fluorescence (m-ICG) has been widely used for assessing real-time blood flow during aneurysm surgery. More recently, an endoscope-integrated indocyanine green fluorescence (e-ICG) has been adopted as a versatile tool during different endoscopic neurosurgical procedures. The purpose of the present report is to evaluate multimodal applications of e-ICG during different endonasal, intraventricular, aneurysm and brain tumor surgeries and provide technical nuances. In addition, we reviewed the literature and identified and compare several overlapping case series of patients treated via an endoscopic integrated indocyanine green fluorescence technique. A total of 40 patients were retrospectively evaluated. Patients were divided into four main groups: (1) endoscopic endonasal approaches (n = 14); (2) ventricular endoscopic approach including patients undergoing third ventriculostomy (n = 8) and tumor biopsy (n = 1); (3) aneurysms surgery (n = 9); and (4) brain parenchymal tumors (n = 8). All patients were successfully treated using the e-ICG dynamic endoscopic visualization, and there were no perioperative complications. Such unique features open up a promising field of applications beyond the use of m-ICG in different surgical field due to the longer duration of e-ICG fluorescence up to 35 ± 7 min. E-ICG represents a new and effective technique for longer real-time visualization of vascular structures preserving normal tissues and functions during different transcranial and endonasal approaches. As the technology and e-ICG resolution improves, the technique has the potential to become a critical tool for different applications in neurosurgery. [ABSTRACT FROM AUTHOR]

Abstract Atherosclerosis is a systemic condition that is responsible for many diseases, and becomes a problem in cases where plaques form at several sites. The formation of a thrombotic embolus may jeopardise vascular operations, including microvascular anastomoses in replantation procedures or free tissue transfers. A mobile imaging tool for the detection of thrombosis preoperatively or intraoperatively would be valuable. An intimal injury, simulating removal of atherosclerotic plaques, was made microsurgically in 60 rat aortas, and results were analysed macroscopically, histologically, and with intraoperative indocyanine green (ICG) videoangiography immediately postoperatively. The Spearman and Pearson correlation tests were used to compare the three techniques. The sensitivity and specificity of ICG videoangiography was calculated in relation to both macroscopic and histological results. Detection of thrombosis was possible in 25 cases, and in 18 cases no thrombosis was correctly diagnosed by all methods used. In 31 of 60 specimens formation of thrombus was detected histologically, and in 29 of 60 examinations it was detected clinically, which yielded a correlation of 93.5% between the two examinations. Macroscopic analysis correlated better with ICG videoangiography (sensitivity 86.2% and specificity 64.5%) than histological observations (sensitivity 80.6% and specificity 62.1%). There was a significant correlation among all comparisons (each p ≤ 0.001) with correlation indexes of 0.94, 0.52, and 0.44 for macroscopic/histological, clinical/ICG videoangiographic, and ICG videoangiographic/histological results, respectively. Our results show that ICG videoangiography is an important method for the detection of formation of acute thrombi and may be an important tool in vascular procedures. [ABSTRACT FROM AUTHOR]

Venous congestion results in tissue damage and remains the most common failure of free microvascular transfer if it is not recognized early. The purpose of this experimental study was to evaluate venous congestion and describe the findings with two different monitoring tools. A standardized epigastric flap was raised, and total occlusion of the draining vein was temporarily applied for 4, 5, 6, or 7 h. Blood flow measurements, including laser-Doppler flowmetry, and tissue spectrophotometry (O2C) and indocyanine green (ICG) videoangiography using the FLOW ® 800 tool, were performed systematically after each surgical step, an interval of venous occlusion, and 1 week of clinical observation. Both monitoring tools were capable of detecting acute venous occlusion. ICG videoangiography data showed a significant decrease in the first and second maximum, and the area under the curve, during venous occlusion, whereas hemoglobin levels in the O2C analysis remained stable. Changes in fluorescence values in border areas of the flap correlated significantly with the incidence of necrosis. O2C data later showed significant correlation with the area of necrosis, and more individual changes during flap monitoring. ICG videoangiography might therefore be useful in the prediction of flap necrosis in critical areas of perfusion. [ABSTRACT FROM AUTHOR]

Background: Mycotic aneurysms, although well recognized, are relatively rare intracranial vascular pathology. These aneurysms are typically located in distal cortical vessels. When these aneurysms are located in eloquent cerebral territories, they may become challenging to treat. Eloquent location may necessitate intraoperative angiographic evaluation to verify complete aneurysmal occlusion/obliteration and preservation of normal adjacent vasculture. Recently, ICG videoangiography has become a widely used intra-operative adjunct and is an important tool used to assess complete occlusion and vessel patency at the conclusion of clip reconstruction. In this report, we outline the comprehensive and concurrent utilization of both vascular imaging modalities to ensure safe and complete occlusion of a mycotic aneurysm.Methods: We describe our experience with a patient with left M4, Rolandic, enlarging mycotic aneurysm that was treated in a comprehensive fashion with microsurgery and intra-operative angiography (IA).Conclusions: ICG videoangiography, in combination with concurrent intraoperative angiography in the setting of complex vascular lesions, may support intraoperative decision-making and provide demonstration of complete occlusion in an immediate fashion. A hybrid operative suite allows for high-quality imaging confirming complete resection. [ABSTRACT FROM AUTHOR]

Background: Spinal hemangioblastoma originating from the film terminale are rare tumors. Here, we present a film terminale hemangioblastoma and review the appropriate literature. Case Description: A 37-year-old female presented with bilateral lower extremity pain without a focal neurological deficit. The magnetic resonance (MR) image demonstrated an intradural spinal tumor at the L1 level, which was accompanied by peritumoral cysts. In addition, there were multiple surpentine flow voids (e.g., consistent with torturous and convoluted vessels), which is typical for hemangioblastoma. At surgery, a spinal hemangioblastoma originating from the film terminale with peritumoral cysts at the L1 level was fully excised without producing a focal postoperative neurological deficit. Histological examination revealed stromal cells with vacuolated cytoplasm and small nuclei in a rich capillary network accompanied by several enlarged vessels. These finding were compatible with a hemangioblastoma. Conclusions: We reported a rare case of a hemangioblastoma originating from the conus presenting at the L1 level. Complete surgical resection was accomplished without any motor deficit. [ABSTRACT FROM AUTHOR]

Objective and Background: To evaluate possible roles for indocyanine green (ICG)-based FLOW 800 software in surgical treatment of cerebral arteriovenous malformations (AVMs). Methods: We perform ICG videoangiography several times for each step of AVM resection to elucidate feeders, drainers, and cerebral perfusion. Results: Since 2010, 22 AVM surgeries in our department have been conducted using FLOW 800 intraoperatively. We demonstrated ICG angiograms, color-coded images, and semi-quantitative curves for AVMs. By reviewing all these modalities, we would define vascular structure of the AVM, proceed with resection, and finally recheck for any remnant. Conclusions: ICG FLOW 800 software helps the surgeon to recognize feeding and draining vessels of an AVM intraoperatively. Further studies to evaluate semi-quantitative acquired data regarding blood flow and tissue perfusion are warranted. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study is to assess the efficacy of intraoperative indocyanine green videoangiography (ICG-VA) using postoperative digital subtraction angiography (DSA) in clipped anterior circulation aneurysms. Materials and Methods: A prospective study was conducted for 1 year which included thirty patients of anterior circulation aneurysm treated by clipping of aneurysm. Intraoperative ICG-VA was performed on all the patients. Postoperative DSA was performed to assess the efficacy of ICG-VA. Results: Intraoperative ICG-VA revealed the occlusion of aneurysm in all the thirty patients. Postoperative DSA revealed aneurysm neck remnant in two patients and demonstrated no branch occlusion. Conclusions: Intraoperative ICG-VA is useful in assessing the completeness of clipping of cerebral aneurysms and ensures patency of branch vessels, thus providing a better postoperative outcome. It replaces the need for invasive postoperative angiographic imaging in a selected group of patients and is also cost effective. [ABSTRACT FROM AUTHOR]

Background: Fusiform aneurysms in the posterior inferior cerebellar artery (PICA) are rare and challenging to treat. Surgical treatment options for a fusiform aneurysm in the PICA include trapping with/without bypass and wrap-clipping, when elimination of the pathological wall from the systemic circulation and prevention of perforator injury are important. In addition, lower cranial nerve impairment due to surgical manipulation should also be avoided. Method: A fusiform-shaped aneurysm was found in a proximal part of the PICA by magnetic resonance angiography undertaken for evaluation of repeated vertigo in a 36-year-old man. The patient underwent direct surgery via a lateral suboccipital transcondylar fossa approach. The entrance of the pseudolumen was the only part to be wrapped and obstructed by clip application, through the corridor between the acoustic and glossopharyngeal nerves to avoid lower cranial nerve injury. Results: Indocyanine green (ICG) videoangiography demonstrated obliteration of pseudolumen and patency of peripheral PICA and perforator contributing to the medulla oblongata. The postoperative course was uneventful without periprocedural complications, including dysphagia and hoarseness. Conclusions: Partial wrap-clipping technique for obstruction of the entrance into a pseudolumen is one of alternatives for dissecting fusiform-shaped aneurysm in the PICA. ICG videoangiography was helpful to confirm the obliteration of the pseudolumen and patency of parent vessel and perforators. [ABSTRACT FROM AUTHOR]

We present our recent experience with fluorescein sodium videoangiography (FLVA) in the intra-operative evaluation of a patient with conus medullaris arteriovenous malformation (AVM). To our knowledge this is the first report in the literature of use of FLVA in the surgery of spinal AVM. Intra-operative FLVA was done to identify an early filling vessel and to obliterate the site of fistulous connection. This was correlated and confirmed with simultaneous indocyanine green videoangiography (ICGVA). The conus and cauda equina roots could be appreciated and manipulated in relation to this fluorescence. Obliteration was confirmed with FLVA and correlated with ICGVA. There was no untoward reaction to the dye injection. We conclude that FLVA is a useful adjunct in the surgical treatment of conus medullaris AVMs since it is a real time, noninvasive, radiation-free, easily reproducible technique allowing surgical manipulation through the operating oculars with simultaneous visualization of surrounding critical structures. [ABSTRACT FROM AUTHOR]

Objective Indocyanine green videoangiography (ICG-VA) is a valuable tool to assess vessel and aneurysm patency during neurovascular surgical procedures. However, ICG-VA highlights vascular structures, which appear white over a black background. Anatomic relationships are sometimes difficult to understand at first glance. Dual-image videoangiography (DIVA) enables simultaneous visualization of light and near-infrared fluorescence images of ICG-VA. Methods The DIVA system was mounted on an OPMI Pentero Flow 800 intraoperative microscope. DIVA was used during microsurgical procedures on 5 patients who were operated for aneurysm clipping and superficial temporal artery–middle cerebral artery bypass. Results DIVA provides real-time simultaneous visualization of aneurysm and vessels and surrounding structures including brain, nerves, and surgical clips. Although visual contrast between vessels and background is higher with standard black-and-white imaging, DIVA makes it easier to understand anatomic relationships between intracranial structures. DIVA also provides better vision of the depth of field. Conclusions DIVA has the potential to become a widely used intraoperative tool to check patency of intracranial vessels. It should be considered as an adjunct to standard ICG-VA for better understanding of vascular anatomy in relation to surrounding structures and can have an impact on decision making during surgery. [ABSTRACT FROM AUTHOR]

Objective The preservation of normal peri/intralesional bridging veins is extremely important in every microneurosurgical operation. The purpose of our study was to describe the “squeeze maneuver” assisted by indocyanine green videoangiography (ICGV), a simple technique to “resuscitate” partially occluded bridging veins during microneurosurgical operations. Methods When a bridging vein is inadvertently stretched up to its collapse during microneurosurgical procedures, a precise identification of the partially occluded zone is carried out under high magnification (10–15×), as well as with the aid of the ICGV. If a continuous irrigation with isotonic saline solution does not allow one to reestablish the venous flow, the “squeeze maneuver” is carried out. This consists of squeezing and sliding with the bipolar forceps the occluded vessel along the normal venous flow direction. This procedure is repeated several times, while a continuous saline irrigation is applied. The ICGV is performed to confirm an adequate patency of the vein. Results This maneuver permits to restore the normal diameter of the vein and blood flow inside it. Conclusion The “squeeze maneuver” assisted by ICGV represents a safe, clean, fast, and even cheap method for restoring the flow of partially occluded bridging veins during microneurosurgical operations. [ABSTRACT FROM AUTHOR]

Background Preservation of the superficial Sylvian veins (SSVs) is essential to prevent neurologic deficits during Sylvian dissection. We describe an appropriate surgical approach for unruptured middle cerebral artery (MCA) aneurysms to preserve these veins by using indocyanine green videoangiography (ICG-VA). Methods Between August 2014 and August 2015, we performed microsurgical clipping for 37 unruptured MCA aneurysms in 36 patients. We classified all of the cases into 3 types according to the location between the Sylvian fissure and the SSV. We defined 3 surgical approaches (frontosylvian, intersylvian, and temporo-sylvian) based on the SSV and investigated the proper surgical approach according to the type of case. Results In our study, most SSVs were located above the Sylvian fissure (fissure type, 64.9%). The SSV was located on the temporal lobe in 10 cases (temporal type) and on the frontal lobe in 3 cases (frontal type). The frontosylvian approach (splitting between the SSV and frontal lobe) was performed in all of the patients with temporal type; the temporo-sylvian approach (splitting between the SSV and temporal lobe) was performed in all of the patients with frontal type and single SSV of fissure type. The intersylvian approach (splitting between the frontal and temporal SSV, or among multiple SSVs) was successfully performed in the patients with double or multiple SSVs of fissure type. No venous complications occurred that were related to the surgical approach. Conclusions Correct dissection strategy using intraoperative ICG-VA is greatly useful to define the optimal surgical approach without vein injury. [ABSTRACT FROM AUTHOR]

Background: Superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass remains an essential tool for managing complex cerebrovascular conditions. A crucial surgical step is the identification and safe dissection of the bypass donor artery. If the frontal branch of the STA is used, a curvilinear fronto-temporal scalp flap generally allows for a clean dissection from the underside of the scalp flap. This dissection is sometimes tedious, since the frontal branch is not always easily visible and due to variability of its anatomy. With this article, we report on the feasibility and effectiveness of a simple indocyanine green videoangiography (ICG-VA)-assisted technique for the identification of the STA branches from the underside of a fronto-temporal scalp flap in bypass surgery. Methods: The technique is based on the analysis of the difference in timing of filling of scalp vessels illuminated via ICG-VA from the underside of a scalp flap. Three illustrative cases are reported. Results: ICG-VA permitted the correct identification and safe dissection of the donor vessels (STA branches) in all three patients. There were no complications due to the ICG-VA. Conclusions: This technique allows reliable visualization of the STA and its branches at once before microsurgical dissection. The information provided by ICG-VA enables precise mapping and preparation of the STA. The simplicity and safety of this technique make it an effective tool for intraoperative identification of the STA and its branches. [ABSTRACT FROM AUTHOR]

Background: Indocyanine green (ICG) videoangiography is an intraoperative technique recently used in vascular neurosurgery to assess the presence or absence of blood flow during critical times of a procedure. These include, but are not limited to, detecting whether daughter branches or perforators are patent after placing a vascular clip or determining whether an aneurysm has been completely isolated from the cerebral circulation after clipping. We present a case of a lesscommonly reported application of ICG videoangiography involving the selection of a vessel to act as the bypass recipient once the need is identified during the surgical treatment of a complex intracranial aneurysm. Case Description: A 51yearold male presented with a ruptured dissecting superior cerebellar artery (SCA) aneurysm that had two branches arising from the dome. Due to the difficult morphology of this aneurysm, a superficial temporal artery to SCA bypass was planned. We used ICG videoangiography to identify the branch that had insufficient retrograde flow via collateral circulation, to which the bypass was performed, followed by the isolation of the aneurysm from the cerebral circulation using permanent surgical clips. Conclusion: Our case represents a possible use of ICG videoangiography during the operative treatment of a difficult aneurysm. Our patient suffered no infarcts postoperatively. In the correct clinical context, this method represents a possible treatment option for complex aneurysms requiring a bypass. [ABSTRACT FROM AUTHOR]

Purpose: Initial successful surgical treatment of pituitary adenomas is crucial to reach long-term remission. Indocyanine green (ICG) videoangiography (VA) is well established in vascular neurosurgery nowadays and several reports described ICG application in brain tumor surgery. We designed this study to evaluate the feasibility of intravenous application of ICG and visualisation of a pituitary lesion via the fluorescence mode of the operation microscope. Methods: 22 patients with pituitary adenomas were treated with transsphenoidal microsurgery and were included in this study. Intraoperatively 25 mg ICG was administered intravenously and visualized via the fluorescence mode of the operation microscope (Pentero/Zeiss). Results: 22 patients qualified for transsphenoidal surgery presenting with different clinical symptoms (13 patients with acromegaly, 6 with M. Cushing and 3 with other symptoms like vision disorder or dizziness) and identification of a pituitary lesion (21 of 22 patients) in preoperative MR-imaging (mean diameter: 9 mm; SD 3.6; 6 macroadenomas, 15 microadenomas, 1 MR-negative). In all 22 patients ICG VA was performed during surgery. No technical failures or adverse events after drug administration occurred. Visualization was optimal approximately 2.4 min after intravenous application. In all patients the adenoma could be detected via two different types of visualization: direct visualization by fluorophore emission versus indirect detection of the adenoma by a lower ICG fluorescence compared to the surrounding tissue. Conclusion: Our data show that intraoperative ICG VA can be a useful and easily applicable additional diagnostic tool for visualization of pituitary lesions using the microscopic approach. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the efficacy of FLOW 800 (Carl Zeiss Meditec, Jena, Thuringia, Germany) with indocyanine green (ICG) videoangiography for the quantitative assessment of flow dynamics in spinal dural arteriovenous fistula (dAVF) surgeries. We prospectively enrolled nine patients with spinal dAVF diagnosed within the past year and performed FLOW 800 analyses using ICG videoangiography before and after surgical obliteration of the fistula. A color-coded map was semi-automatically generated by FLOW 800 and used for high-resolution visualization of the vasculature and instant interpretation of the dynamic flow changes. The FLOW 800-specific hemodynamic parameters were employed for real-time measurements of parenchymal perfusion alterations. Overall, 18 intraoperative FLOW 800 analyses using ICG videoangiography were performed in nine patients. The color-coded map aided the detection and complete obliteration of the fistulas in all patients and the results were verified by postoperative spinal digital subtraction angiography. The transit time parameter was significantly shorter in the preobliteration phase than in the postobliteration phase ( p < 0.01), the rise time parameter exhibited the same pattern ( p = 0.08) and maximum intensity and blood flow index were not significantly different between these phases. FLOW 800 with ICG videoangiography provided an intuitive and objective understanding of blood flow dynamics intraoperatively and enabled easy and confident identification and treatment of this pathology. The FLOW 800-specific hemodynamic analyses provided additional perfusion information that enabled real-time measurements of parenchymal perfusion alterations. FLOW 800 with ICG videoangiography is useful for intraoperative quantitative assessment of flow dynamics, facilitating safety and confidence in the treatment of spinal dAVF. [ABSTRACT FROM AUTHOR]

Background and purpose: To more safely resect pathological lesions during spinal vascular lesion surgery, it is most important to understand local abnormal hemodynamics in detail. New devices or techniques that make out intraoperative local hemodynamics have been awaited. To introduce a resourceful method, we present a case of spinal hemangioblastoma for which temporary arterial occlusion during near-infrared intraoperative indocyanine green (ICG) videoangiography gives useful assessment of the main and minor feeders easily. Methods: A 36-year-old female suffered progressive paresthesia of both lower extremities for 12 months and gait disturbance for 2 weeks. A neurological examination revealed T10 myelopathy. Magnetic resonance imaging (MRI) of the thoracic spine showed an intramedullary tumor at the T8 level and severe spinal cord edema with a flow void in the extended dorsal spinal veins. Spinal angiography showed a hemangioblastoma at the T8 level, with two main feeders and minor feeders. Results: She underwent total resection of the tumor by a posterior approach. During the intraoperative ICG videoangiography, temporary arterial occlusion of the two main feeders and FLOW800 analysis enabled clear understanding of the vasculature, especially of the two minor feeders. At the 9-month follow-up, her neurological manifestation was partially resolved, and post-operative MRI showed total removal of the tumor and disappearance of the spinal cord edema. Conclusions: Temporary clipping of the main feeders during intraoperative ICG videoangiography is very useful for easily determining the minor feeding arteries, and helpful for maintaining normal perfusion of the spinal cord in spinal hemangioblastoma surgery. Furthermore, the FLOW 800 analysis, especially the false color-coded variation, increased our understanding of the hemodynamics. [ABSTRACT FROM AUTHOR]

Background: The potential utility of intraoperative microscope-integrated indocyanine green (ICG) fluorescence angiography in the surgery of brain arteriovenous malformations (AVMs) and evaluation of the completeness of resection is debatable. Postoperative catheter angiography is considered the gold standard. We evaluated the value of ICG and intraoperative catheter angiography in this setting. Methods: Between January 2009 and July 2013, 37 patients with brain AVMs underwent surgical resection of their vascular lesions. ICG videoangiography and an intraoperative catheter angiography were performed in 32 cases, and a routine postoperative angiogram was performed within 48 h to 2 weeks after surgery. The usefulness of ICG findings and the ability to confirm total resection and to identify residual nidus or persistent shunt were assessed and compared to intraoperative and postoperative digital subtraction angiography, respectively. Results: There were 7 grade 1, 11 grade 2, 11 grade 3 and 3 grade 4 Spetzler-Martin classification AVMs. ICG angiography helped to distinguish AVM vessels in 26 patients. In 31 patients, it demonstrated that there was no residual shunting. In one patient, a residual AVM was identified and further resected. Intraoperative catheter angiography detected two additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. Further resection of the AVM was performed, and total resection was confirmed by a repeat intraoperative angiogram. Postoperative angiography in a patient with a grade 4 lesion revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intraoperative angiography. Overall ICG angiography missed three out of four residual AVMs after initial resection, while the intraoperative angiogram missed one. Conclusion: Although ICG angiography is a helpful adjunct in the surgery of some brain AVMs, it's yield in detecting residual AVM nidus or shunt is low, especially for deep-seated lesions and higher grade AVMs. ICG angiography should not be used as a sole and/or reliable technique. High-resolution postoperative angiography must be performed in brain AVM surgery and remains the best test to confidently confirm complete AVM resection. [ABSTRACT FROM AUTHOR]

Objective To evaluate the quantitative assessment of flow dynamics during surgery for arteriovenous malformations (AVMs) with FLOW 800 with indocyanine green videoangiography. Methods Changes in flow dynamics in the superficial AVM components (feeder, nidus, and drainer), the adjacent cortical artery, and the cortical vein surrounding AVM were evaluated. Analysis was performed at predissection, postclipping of the feeders, and postresection of the nidus with the use of quantitative values of the maximum fluorescence intensity, time to half-maximum fluorescence intensity (T 1/2 FI), and the fluorescence intensity rate at T 1/2 FI semiautomatically obtained with the use of FLOW 800 software. Results FLOW 800 assessments were performed in 7 cases. The time difference between the T 1/2 FI, defined as transit time, in the cortical artery and the drainer was prolonged from 0.08 ± 0.65 seconds to 2.63 ± 1.79 seconds ( P < 0.0001) at postfeeder clipping phase. The transit time between the cortical artery and the cortical vein was reduced to 3.76 ± 1.37 seconds at post feeder clipping phase ( P = 0.024) and 2.63 ± 0.80 seconds at final phase ( P = 0.005) compared with 4.56 ± 1.47 seconds at predissection phase. The maximum intensity and the fluorescence intensity rate at T 1/2 FI were not significantly different at these phases, excluding the maximum intensity of the drainer decreasing from 533 ± 271 to 399 ± 217 ( P = 0.006) at post feeder clipping phase. Conclusion FLOW 800 analysis with indocyanine green videoangiography provides the real-time hemodynamic status of the AVMs and adjacent brain at various stages of resection. This technique is feasible to resect AVMs more safely and convincingly. [ABSTRACT FROM AUTHOR]

Background: Postoperative cerebral hyperperfusion (HP) is a notable complication that occurs more frequently in moyamoya disease (MMD) than in atherosclerosis. 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 correlation between the ICG peak time and preoperative cerebral blood flow or vascular reserve. 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 run-off and stagnation 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: donor STA size and poor run-off and integrity of the blood brain barrier in the recipient MCA. [ABSTRACT FROM AUTHOR]

Aims and Objectives. Intra-operative Indocyanine Green (ICG) video-angiography (ICG-VA) has become an established aid to cerebrovascular surgery. We describe our experience using this technique to define angio-architecture intraoperatively in a range of spinal vascular malformations. Methods. A retrospective review of notes and imaging was carried out from a prospectively maintained database. Our series comprises 27 patients who underwent surgical treatment between September 2007 and August 2012. We carried out a retrospective review of data from a prospectively maintained database. Results. For slow-flow Type 1 fistulae the ICG videoangiogram demonstrated conclusively that the arteriovenous shunt was obliterated. This is a consideration on the rare occasions where a second fistula is present, an example of which is included in this series. ICG-VA also helps to demonstrate normal vascular anatomy and distinguish these vessels from pathology. For Type II lesions it allowed orientation to the vascular anatomy as demonstrated by the pre-operative angiogram. In one of two cases in this series it ensured to the complete extirpation of a large arteriovenous malformation (AVM). However a second Type II case demonstrated its limitations, as a diffuse intramedullary component could not be identified. Two cases were explored where digital subtraction spinal angiography was not possible and incomplete understanding of the angio-architectures of the lesions were available from Time Resolved dynamic magnetic resonance angiography and/or multi-detector CT angiography. ICG-VA provided invaluable information on alterations in arterio-venous flow that allowed diagnosis and obliteration of the arteriovenous shunts in each case. Discussion. ICG video-angiography is a time-efficient and safe alternative to intra-operative spinal angiography. It provided useful information on haemodynamic changes intraoperatively and completeness of treatment. We discuss its limitations and role in the management of these lesions. [ABSTRACT FROM AUTHOR]