Detection of a residual nidus by surgical microscope-integrated intraoperative near-infrared indocyanine green videoangiography in a child with a cerebral arteriovenous malformation

Combination of intraoperative indocyanine green video-angiography FLOW 800 and computed tomography perfusion to assess the risk of cerebral hyperperfusion syndrome in chronic internal carotid artery occlusion patients after revascularization surgery

Background and purpose

To study the changes of corticocerebral hemodynamics in surgical area and postoperative hyperperfusion syndrome in patients with chronic internal carotid artery occlusion (CICAO) by intraoperative indocyanine green videoangiography (ICGA)-FLOW 800 and CT perfusion after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery.

Methods

From October 2019 to January 2021, 77 patients diagnosed with CICAO underwent direct bypass surgery at Huadong hospital (affiliated with Fudan University) were enrolled. Regions of interest (ROIs) at STA, proximal MCA (PMCA), distal MCA (DMCA), cortical blood capillary (CBC), and cortical vein (CV) were identified after anastomosis by ICGV-FLOW 800 including peak fluorescence intensity (PFI), time to peak (TTP), and area under the time curve (AUC) of fluorescence intensity. All patients underwent perfusion-weighted CT before bypass surgery and those patients with HPS were verified by CTP after bypass.

Results

14 patients with HPS were verified by perfusion-weighted CT after bypass. In HPS group, the AUCTTP of DMCA was significantly larger (T = -3.301, p = 0.004) and TTP of CBC was shorter (T = -2.929, p = 0.005) than patients in non-HPS group. The larger AUCTTP of DMCA (OR = 3.024, 95%CI 1.390-6.578, p = 0.0050) was an independent risk factor by further multivariate logistic regression analysis.

Conclusion

The hemodynamic changes of cortical vessels during STA-MCA bypass surgery could be recorded accurately by ICGV-FLOW 800. Furthermore, the increased AUCTTP of DMCA and shorter TTP of CBC may be potential risk factors of HPS.

Case report: video-assisted thoracoscopic surgery for pulmonary arteriovenous malformation using near-infrared fluorescence with indocyanine green

BACKGROUND

Pulmonary arteriovenous malformation (PAVM) is an abnormal communication between pulmonary vasculatures and has an unclear boundary with surrounding lung tissues. At present, surgeons can only determine its location by preoperative imaging and intraoperative palpation, despite its soft texture. Indocyanine green(ICG), a near-infrared fluorophore, has been demonstrated useful in the accurate identification of vascular tissue. Therefore, we explored its application in PAVM cases.

CASE PRESENTATION

We present two PAVM cases using near-infrared fluorescence (NIF) with 25 mg ICG at 5 mg/ml to achieve intraoperative visualization of the lesion in video-assisted thoracoscopic surgery (VATS). Under the NIF mode, ICG systemic injection led to successive signaling of the anomaly and normal tissues in merely 10 s, which helped us distinguish them efficiently and precisely. A peak signal-to-background ratio of 2.2 confirmed the significant fluorescence difference and excluded interference from carbon dust.

CONCLUSIONS

We are the first to report the use of such an approach in delineating the margin of vascular malformation with high contrast, and this new finding may help minimize the damage to lung function in PAVM treatment. Further exploration and validation are needed to determine its role.

Non-Angry Superficial Draining Veins: A New Technique in Identifying the Extent of Nidus Excision during Cerebral Arteriovenous Malformation Surgery

BACKGROUND

As essential techniques, intraoperative indocyanine green video angiography (ICG-VA) and FLOW 800 have been widely used in microsurgery for arteriovenous malformations (AVMs). In the present report, we introduced a supplementary technical trick for judging the degree of lesion resection when there were superficial drainage veins. FLOW 800 analysis is used to verify our conjecture.

METHODS

A retrospective analysis of a 33 case cohort treated surgically from June 2020 to September 2022 was conducted and their lesions were removed by superficial drainage veins as a supplementary technical trick and analyzed with FLOW800.

RESULTS

In our 33 AVMs, the feeding artery was visualized earlier than the draining vein. Intraoperatively, the T1/2 peak and slope of the draining vein were significantly higher than that of the lesion. However, the maximum fluorescence intensity (MFI) of the draining vein decreased as the procedure progressed (p < 0.001). After reducing the blood flow to the nidus by progressive dissection of the feeding artery, the arteriovenous transit time (AVTT) decreased from 0.64 ± 0.47 s, was prolonged to 2.38 ± 0.52 (p < 0.001), and the MFI and slope of the nidus decreased from the pre-resection 435.42 ± 43.90 AI and 139.77 ± 27.55 AI/s, and decreased to 386.70 ± 48.17 AI and 116.12 ± 17.46 AI/s (p < 0.001). After resection of the nidus, the T1/2 peak of the draining vein increased from 21.42 ± 4.70 s, prolonged to after dissection of the blood feeding artery, 23.07 ± 5.29 s (p = 0.424), and after resection of the lesion, 25.13 ± 5.46 s (p = 0.016), with a slope from 135.79 ± 28.17 AI/s increased to 210.86 ± 59.67 AI/s (p < 0.001).

CONCLUSIONS

ICG-VA integrated with FLOW 800 is an available method for determining the velocity of superficial drainage veins. Whether the color of the superficial drainage veins on the cortical surface returns to normal can determine whether the lesion is completely resected and can reduce the possibility of residual postoperative lesions.

Evaluation of the Utility of Indocyanine Green Video Angiography in Cerebral Arteriovenous Malformation Surgery

OBJECTIVE

To assess the utility of intraoperative indocyanine green video angiography (ICG-VA) during microsurgical resection of arteriovenous malformations (AVMs).

METHODS

Data of the 24 patients, who were surgically treated for AVM using intraoperative ICG-VA, were reviewed retrospectively. Postoperative digital subtraction angiography (DSA) was performed in all patients before they regained consciousness and became fully awake, and the results were compared with those obtained with intraoperative ICG-VA. A scheduled DSA was performed in all patients in the third, sixth, and 12th postoperative months as well.

RESULTS

Authors retrospectively analyzed the records of intraoperative ICG-VA application of all 24 patients. Though the exposures were limited and the image qualities were poor at higher magnification on the surgical microscope within deep surgical fields, the AVM niduses, feeding arteries, draining veins, and their relations to normal vasculature were observed precisely with ICG-VA in all the procedures. Furthermore, the visualization was not qualified enough to identify these pathological vascular structures accurately before evacuating and irrigating the layer of blood clots that obscure the view in patients who presented with hemorrhage. In a patient in our series, a residual nidus in the tail of the caudate nucleus was detected with immediate postoperative DSA which was not revealed by terminal assessment with final intraoperative ICG-VA.

CONCLUSIONS

Intraoperative ICG-VA is particularly effective in the identification of the feeder, nidus, and drainer and in the assessment of the flow dynamics of the nidus in cerebral AVM surgery. It may be a quick and safe technique for intraoperative imaging of the angioarchitecture of superficial AVMs, but it may be less helpful for deep-seated lesions. Furthermore, this method alone may not be useful in the identification of residual disease or improvement of the clinical outcomes. DSA has remained the gold standard for confirming AVM obliteration. Despite the technical limitations associated with ICG-VA, a combination of intraoperative ICG-VA and immediate postoperative DSA may advance the safety and efficacy of AVM surgery.

Multimodality Management in bAVM Surgery - Recent Experience from International Cerebrovascular Fellowship

Background:

Arteriovenous malformation (bAVM) presents maldevelopment of the brain’s vessels with a direct connection between cerebral arteries and veins. By current data, patients from Spetzler Ponce A (SP) are found to benefit from the treatment. Considering the outcome, most of SP C and some of the SP B are the most debatable.

Objective:

Arteriovenous malformation presents maldevelopment of the brain’s vessels with a consequent direct connection between cerebral arteries and veins. The annual risk of hemorrhage in adults is reported for 2-3 %. They usually present with unilateral headaches seizures and intracranial hemorrhage. By current data, patients from Spetzler Ponce A (SP) are found to benefit from the treatment. Considering the outcome, most of SP C and some of the SP B are the most debatable.

Methods:

The study included a cohort of bAVM patients referred to Fujita Health University Bantane Hotokukai Hospital, Nagoya, Aichi, Japan where the main author (AA) has completed an international cerebrovascular fellowship under the mentorship of Professor Yoko Kato. Japanese Stroke Guidelines (JSG) were used for the treatment decision. Patients were graded according to the Spetzler Ponce (SP) system. Considering American Heart Association criteria (AHA), embolization was used as a part of multimodal treatment. Intraoperative microscopic video tools included Indocyanine green ICG, FLOW 800 and dual image video angiography DIVA. Clinical outcomes were measured using Modified Ranking Score (mRs).

Results:

A total of eleven patients with brain bAVM were studied with a median age of 32 years [IQR = 22-52]. There were ten patients presented with supratentorial and a single patient with infratentorial AVM. Patients were graded according to the Spetzler Ponce (SP) system. There were eight patients in SP A (72,7%), one in group B (9 %) while the rest of them were in C (18 %). Two patients had associated aneurysms that required treatment. The median size of the AVM nidus was 3,50 cm [IQR= 2-5]. Deep venous drainage was found in six patients while three were located in eloquent zones. Clinical outcomes were considered good by mRs <2 in eight patients, seven from the surgically treated group (72,7 % respectively). Surgery median length time was 427, 5 minutes; [IQR =320 - 463] with complete AVM resection in all patients and no mortality recorded in this cohort with the median follow up of 39,5 months [IQR = 19-59].

Conclusion:

Ideal management of bAVM is still controversial. Those complex vascular lesions require multimodal treatment in a majority of cases in highly specialized centers. In SP A patients, surgery provides the best results with a positive outcome and a small number of complications. With the improvement of endovascular feeder occlusion SP B patients become prone to a more positive outcome. Nowadays, intraoperative microscopic tools such as FLOW 800, ICG and DIVA are irreplaceable while improving safety to deal with bAVM. For SP C patients, a combination of endovascular and stereotactic radiosurgery was found to be a good option in the present time.

Augmented Reality Fluorescence Imaging in Cerebrovascular Surgery: A Single-Center Experience with Thirty-Nine Cases

BACKGROUND

Several intraoperative imaging methods exist in cerebrovascular surgery to visualize and analyze the vascular anatomy flow. A new method based on multispectral fluorescence (MFL) imaging of indocyanine green (ICG) video angiography (VA) allows real-time, augmented reality (AR) visualization of blood flow superimposed on white-light microscopic images. We describe our single-center experience using MFL AR in cerebrovascular surgery.

METHODS

Case descriptions are provided of cerebrovascular surgery with intraoperative use of MFL AR images performed at our institution from June 2018 to April 2020. MFL superimposes the blood flow in real time on white-light microscopic images. We used MFL AR imaging as well as standard ICG-VA visualization and intraoperative digital subtraction angiography (DSA) as a control.

RESULTS

A total of 39 cases (33 aneurysm clippings, 4 arteriovenous malformations, and 2 external carotid-internal carotid bypass surgeries), were performed using MFL technology-based AR visualization of ICG. MFL AR imaging and DSA showed a high correlation concerning aneurysm occlusion and vessel patency. In arteriovenous malformation resection surgery, MFL AR imaging facilitated early identification of the feeding arteries and draining veins. Because of increased sensitivity of MFL AR, a reduced dose of ICG could be used, allowing repeated intraoperative imaging. There were no postoperative complications, side effects, or technical problems related to the use of MFL AR imaging.

CONCLUSIONS

MFL AR is an easy-to-use adjunct in cerebrovascular surgery and shows a high correlation with intraoperative DSA. No interruption of the surgery is necessary because MFL AR images of the blood flow are superimposed in real time on white-light microscopic images.

The Use of Indocyanine Green Fluorescence Angiography in Pediatric Surgery: A Systematic Review and Narrative Analysis

Purpose: Indocyanine green fluorescence angiography (ICG-FA) is a validated non-invasive imaging technique used to assess tissue vascularization and guide intraoperative decisions in many surgical fields including plastic surgery, neurosurgery, and general surgery. While this technology is well-established in adult surgery, it remains sparsely used in pediatric surgery. Our aim was to systematically review and provide an overview of all available evidence on the perioperative use of indocyanine green fluorescence angiography in pediatric surgical patients. Methods: We conducted a systematic review with narrative synthesis in conformity with the PRISMA guidelines using PubMed, Medline, All EBM Reviews, EMBASE, PsycINFO, and CINAHL COMPLETE databases to identify articles describing the perioperative use of ICG-FA in pediatric patients. Two independent authors screened all included articles for eligibility and inclusion criteria. We extracted data on study design, demographics, surgical indications, indocyanine green dose, and perioperative outcomes. We developed a risk of bias assessment tool to evaluate the methodological quality of included studies. Results: Of 1,031 articles retrieved, a total of 64 articles published between 2003 and 2020 were included reporting on 664 pediatric patients. Most articles were case reports and case series (n = 36; 56%). No adverse events related to ICG-FA were reported in the included articles. Risk of bias was high. We did not conduct a meta-analysis given the heterogeneous nature of the populations, interventions, and outcome measures. A narrative synthesis is presented. Conclusion: Indocyanine green fluorescence angiography is a safe imaging technology and its use is increasing rapidly in pediatric surgical specialties. However, the quality of evidence supporting this trend currently appears low. Case-control and randomized trials are needed to determine the adequate pediatric dose and to confirm the potential benefits of ICG-FA in pediatric surgical patients. Systematic Review Registration: This study was registered on Prospero a priori, identifier: CRD42020151981.

Hemodynamic changes in superficial arteriovenous malformation surgery measured by intraoperative ICG fluorescence videoangiography with FLOW 800 software

Background

Arteriovenous malformation(AVM) have long-term "blood stealing" characteristics, which result in complicated hemodynamic features. To analyze the application of intraoperative indocyanine green angiography with FLOW 800 software in AVM surgeries.

Methods

Data on 17 patients undergoing surgery with ICG fluorescence were collected in Beijing Tiantan Hospital. To analyze the hemodynamic features of AVM and the influence on the peripheral cortex of AVM resection, we assessed the following hemodynamic parameters: maximum intensity, slope of rise, time to half-maximal fluorescence, and transit time from arteries to veins.

Results

In the 17 superficial AVMs studied, the time-delay color mode of the FLOW 800 software was superior to the traditional playback mode for identifying feeding arteries, draining veins, and their relation to normal cortical vessels. The maximum fluorescence intensity and slope of the ICG fluorescence curve of feeder arteries and draining veins were higher than those of normal peripheral vessels (P < 0.05). The transit times in AVMs were significantly shorter than those in normal peripheral vessels (P < 0.05). After AVM resection, cerebral flow increased in the cortex, and local cycle time becomes longer, although the differences were not significant (P > 0.05).

Conclusions

Hemodynamic parameter analysis provided quality guidance for the resection of AVMs and could also be used in estimating changes in blood flow in the local cortex to identify abnormal hyperperfusion and residual nidus.

Application of Indocyanine Green During Arteriovenous Malformation Surgery: Evidence, Techniques, and Practical Pearls

Indocyanine green (ICG) is a fluorescent molecule that enables visualization of hemodynamic flow through blood vessels. The first description of its application to the resection of arteriovenous malformations (AVMs) did not occur until 2007. Since then, industry leaders have rapidly integrated this optical technology into the intraoperative microscope, and the use of ICG videoangiography (VA) has since become routine in AVM surgery among some academic centers. A number of case series have been published since the introduction of ICG VA to AVM neurosurgery. These early reports with small sample sizes were largely qualitative, assigning to the technology “usefulness” and “benefit” scores as perceived by the operators. This lack of objectivity prompted the development of FLOW 800 software, a proprietary technology of Carl Zeiss Meditec AG (Oberkochen, Germany) that can quantify relative fluorescence intensity under the microscope to generate color maps and intensity curves for ad hoc and post hoc analyses, respectively. However, subsequent case series have done little to quantify the effect of ICG VA on outcomes. The available literature predominately concludes that ICG VA, although intuitive to deploy and interpret, is limited by its dependence on direct illumination and visualization. The subcortical components of AVMs represent a natural challenge to ICG-based flow analysis, and the scope of ICG VA has therefore been limited to AVMs with a high proportion of superficial angioarchitecture. As a result, digital subtraction angiography has remained the gold standard for confirming AVM obliteration. In this review, we provide an overview of the existing literature on ICG VA in AVM resection surgery. In addition, we describe our own experiences with ICG VA and AVMs and offer the senior author's surgical pearls for optimizing the marriage of fluorescence flow technology and AVM resection surgery.

Blood Flow Assessment of Arteriovenous Malformations Using Intraoperative Indocyanine Green Videoangiography

Intraoperative indocyanine green (ICG) videoangiography is widely used in patients undergoing neurosurgery. FLOW800 is a recently developed analytical tool for ICG videoangiography to assess semi-quantitative flow dynamics; however, its efficacy is unknown. In this study, we evaluated its functionality in the assessment of flow dynamics of arteriovenous malformation (AVM) through ICG videoangiography under clinical settings. ICG videoangiography was performed in the exposed AVM in eight patients undergoing surgery. FLOW800 analysis was applied directly, and gray-scale and color-coded maps of the surgical field were obtained. After surgery, a region of interest was placed on the individual vessels to obtain time-intensity curves. Parameters of flow dynamics, including the maximum intensity, transit time, and cerebral blood flow index, were calculated using the curves. The color-coded maps provided high-resolution images; however, reconstruction of colored images was restricted by the depth, approach angle, and brain swelling. Semi-quantitative parameters were similar among the feeders, niduses, and drainers. However, a higher cerebral blood flow index was observed in the feeders of large AVM (>3 cm) than in those of small AVM (P < 0.05). Similarly, the cerebral blood flow index values were positively correlated with the nidus volume (P < 0.01). FLOW800 enabled visualization of the AVM structure and safer resection, except in case of deep-seated AVM. Moreover, semi-quantitative values in the individual vessels through using ICG intensity diagram showed different patterns according to size of the AVM. ICG videoangiography showed good performance in evaluating flow dynamics of the AVM in patients undergoing surgery.

Doxorubicin and indocyanine green loaded superparamagnetic iron oxide nanoparticles with PEGylated phospholipid coating for magnetic resonance with fluorescence imaging and chemotherapy of glioma

Background

Glioma represents the most common malignant brain tumor. Outcomes of surgical resection are often unsatisfactory due to low sensitivity or resolution of imaging methods. Moreover, the use of traditional chemotherapeutics, such as doxorubicin (DOX), is limited due to their low blood-brain barrier (BBB) permeability. Recently, the development of nanotechnology could overcome these obstacles.

Materials and methods

Hydrophobic superparamagnetic iron oxide nanoparticles (SPIO NPs) were prepared with the use of thermal decomposition method. They were coated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG 2000) and DOX using a thin-film hydration method followed by loading of indocyanine green (ICG) into the phospholipid layers. Details regarding the characteristics of NPs were determined. The in vitro biocompatibility and antitumor efficacy were established with the use of MTT assay. In vivo fluorescence and magnetic resonance (MR) imaging were used to evaluate BBB penetration and accumulation of NPs at the tumor site. Antitumor efficacy was evaluated using measures of tumor size, median survival times, body weights, and H&E staining.

Results

The multifunctional NPs generated had an average diameter of 22.9 nm, a zeta potential of -38.19 mV, and were capable of providing a sustained release of DOX. In vitro experiments demonstrated that the SPIO@DSPE-PEG/DOX/ICG NPs effectively enhanced cellular uptake of DOX as compared with that of free DOX. In vivo fluorescence and MR imaging revealed that the NPs not only effectively crossed the BBB but selectively accumulated at the tumor site. Meanwhile, among all groups studied, C6 glioma-bearing rats treated with the NPs exhibited the maximal degree of therapeutic efficacy, including smallest tumor volume, lowest body weight loss, and longest survival times, with no obvious side effects.

Conclusion

These results suggest that the SPIO@DSPE-PEG/DOX/ICG NPs can not only function as a nanoprobe for MR and fluorescence bimodal imaging, but also as a vehicle to deliver chemotherapeutic drugs to the tumor site, to achieve the theranostic treatment of glioma.

Use of Indocyanine Green Fluorescence Endoscopy to Treat Concurrent Perimedullary and Dural Arteriovenous Fistulas in the Cervical Spine

BACKGROUND

Intraoperative microscopic fluorescence angiography using indocyanine green (ICG) provides visual information on real-time blood flow. However, this method cannot be applied for lesions that are not visible under microscopic imaging because excitation light does not reach the targeted vascular structures. Endoscope-integrated ICG video-angiography has recently been advocated to compensate for this limitation. This is the first reported case of a spinal arteriovenous malformation in which endoscope-integrated ICG video-angiography was successfully used.

CASE DESCRIPTION

We report the case of a 63-year-old man who presented with a subarachnoid hemorrhage from a spinal arteriovenous malformation at the C3 level. We chose the direct surgery option with a posterior approach to treat this lesion. Although the preoperative diagnosis was a perimedullary arteriovenous fistula (AVF) with multiple feeders, we found concurrent dural AVF and perimedullary AVFs during surgery. We introduced an endoscope and performed endoscope-integrated ICG video-angiography because it was difficult to identify the angioarchitectures of the perimedural and dural AVFs on the ventral surface of the spinal cord under microscopic view alone. Endoscope-integrated ICG video-angiography gave us clear and magnified angioarchitectures of these lesions. The fistulous point and the varix of the perimedullary AVF was coagulated and dissected under endoscopic view, and the draining vein of the dural AVF was also coagulated and dissected at the origin from the dura mater under microscopic view.

CONCLUSIONS

A posterior approach with the assistance of an endoscope and endoscope-integrated ICG video-angiography is feasible for spinal vascular diseases located ventrally.

Usefulness of repetitive intraoperative indocyanine green-based videoangiography to confirm complete obliteration of micro-arteriovenous malformations

Background:

It is difficult to intraoperatively confirm the total disappearance of arteriovenous (AV) shunts during surgery for microarteriovenous malformations (micro-AVMs), especially when the nidus is extremely small or diffuse on preoperative angiography. Although intraoperative angiography is effective for evaluating residual shunts, procedure-related risks raise important concerns. The purpose of this study was to assess the usefulness of intraoperative indocyanine green-based videoangiography (ICG–VA) to determine complete disappearance of micro-AVMs during surgery.

Methods:

We retrospectively analyzed eight patients with ruptured micro-AVMs who were treated using craniotomy with ICG–VA at our institution.

Results:

Two patients underwent emergency partial evacuation of hematoma and external decompression before the diagnostic angiography. While three patients had a nidus smaller than 1 cm, five patients had only early draining veins without an appreciable nidus. The draining veins were superficial in six cases and deep in two cases. The average interval from onset to surgery was 33 days (range, 2–57). ICG–VA was repetitively conducted until disappearance of the AV shunt was confirmed. No residual AV shunt was observed on postoperative radiological examinations. In all cases, the diagnosis of AVM was confirmed from the results of postoperative pathological examination.

Conclusions:

ICG–VA could detect early draining veins more clearly in situ than diagnostic angiography. Although it is not as effective for visualizing lesions with deep draining veins, repetitive ICG–VA was safe and effective for confirming the disappearance of AV shunts with superficial drainage.

Indocyanine green videoangiography methodological variations: review

Indocyanine green videoangiography (ICGVA) procedures have become widespread within the spectrum of microsurgical techniques for neurovascular pathologies. We have conducted a review to identify and assess the impact of all of the methodological variations of conventional ICGVA applied in the field of neurovascular pathology that have been published to date in the English literature. A total of 18 studies were included in this review, identifying four primary methodological variants compared to conventional ICGVA: techniques based on the transient occlusion, intra-arterial ICG administration via catheters, use of endoscope system with a filter to collect florescence of ICG, and quantitative fluorescence analysis. These variants offer some possibilities for resolving the limitations of the conventional technique (first, the vascular structure to be analyzed must be exposed and second, vascular filling with ICG follows an additive pattern) and allow qualitatively superior information to be obtained during surgery. Advantages and disadvantages of each procedure are discussed. More case studies with a greater number of patients are needed to compare the different procedures with their gold standard, in order to establish these results consistently.

Application of indocyanine green (ICG) fluorescence for endoscopic biopsy of intraventricular tumors

BACKGROUND

Many reports have already indicated the benefit of pathological diagnosis of intra- and periventricular tumors with neuroendoscopic biopsy. However, it is also well known that studies can be occasionally inconclusive because of the small and/or inadequate samples for identification of abnormal tissues. The application of indocyanine green (ICG) fluorescence for endoscopical tumor biopsy under the intraventricular surroundings is a new area not previously reported. We attempted visual differentiation of intraventricular lesions from the surrounding structure using ICG fluorescence and considered the most appropriate region for biopsy.

METHODS

Three cases (13–14 year-old boys) with secondary hydrocephalus caused by intra- and periventricular tumors were operated for endoscopic transventricular biopsy combined with endoscopic third ventriculostomy. Final pathological diagnoses were suprasellar malignant lymphoma and germ cell tumors in two patients, both associated with intraventricular dissemination. Enhanced tumor visualization with 12.5 mg of ICG administration was obtained using the D-light P light equipment and ICG telescope 5.8 mm/19 cm.

RESULTS

It was possible to identify the tumor mass margins themselves and detect the differences of intratumoral ICG accumulation. The areas of tumor dissemination were identifiable by neuroendoscopy but unable to be visualized by ICG fluorescence.

CONCLUSIONS

We were able to obtain an ICG fluorescence imaging inside the cerebral ventricles by new D-light P system comprised of a camera head telescope. ICG fluorescence with neuroendoscopy can provide useful information for choosing the point of biopsy of intra- and periventricular tumors. However, we need to assess if the ICG accumulation site is the most appropriate for biopsy.

Usefulness of tumor blood flow imaging by intraoperative indocyanine green videoangiography in hemangioblastoma surgery

OBJECTIVE

Hemangioblastomas remain a surgical challenge because of their arteriovenous malformation-like character. Recently, indocyanine green (ICG) videoangiography has been applied to neurosurgical vascular surgery. The aim of this study was to evaluate the usefulness of tumor blood flow imaging by intraoperative ICG videoangiography in surgery for hemangioblastomas.

METHODS

Twenty intraoperative ICG videoangiography procedures were performed in 12 patients with hemangioblastomas. Seven lesions were located in the cerebellum, two lesions were in the medulla oblongata, and three lesions were in the spinal cord.

RESULTS

Ten procedures were performed before or during dissection, and 10 procedures were performed after tumor resection. ICG videoangiography could provide dynamic images of blood flow in the tumor and its related vessels under surgical view. Interpretation of these dynamic images of tumor blood flow was useful for discrimination of transit feeders (feeders en passage) and also for estimation of unexposed feeders covered with brain parenchyma. Postresection ICG videoangiography could confirm complete tumor resection and normalized blood flow in surrounding vessels.

CONCLUSIONS

In surgery for hemangioblastomas, careful interpretation of dynamic ICG images can provide useful information on transit feeders and unexposed hidden vessels that cannot be directly visualized by ICG.

Intra operative indocyanine green video-angiography in cerebrovascular surgery: An overview with review of literature

Microscope integrated Near infra red Indocyanine green video angiography (NIR ICG VA) has been frequently used in cerebrovascular surgery. It is believed to be a simple and reliable method with acquisition of real time high spatial resolution images. The aim of this review article was to evaluate the efficacy of intra operative Indocyanine green video angiography (ICG VA) in Aneurysm, brain arteriovenous malformations (AVM) and extracranial-intracranial (EC-IC) bypass surgeries and also to analyze its limitations. Intra operative imaging is a very useful tool in guiding surgery; thus, avoiding surgical morbidity. Now-a-days, many cerebrovascular units are using ICG VA rather than Doppler and intra operative DSA in most of their aneurysm surgeries, and surgeons are incorporating this technique for AVM and in EC-IC bypass surgeries too. This article is an overview of the beneficial effects of ICG VA in cerebrovascular surgery and will also point out its limitations in various circumstances. Intra operative ICG VA gives high resolution, real time images of arterial, capillary, and venous flow of cerebral vasculature. Although it gives adequate information about the clipped neck, parent/branching artery and perforator involvement, it has some limitations like viewing the neck residuals located behind the aneurysm, thick walled atherosclerotic vessels, and thrombosed aneurysms. In AVM surgery, it is useful in detecting the residual nidus in diffuse type AVM, but cannot be relied in deep seated AVMs and it gives exact information about the anastomosis site in EC-IC bypass, thus, avoiding early bypass graft failure. NIR ICG VA is a simple, reliable, and quick method to pick up subtle findings in cerebrovascular procedures. But in selected cases of aneurysms, endoscopy and intra operative Digital substraction angiography (DSA) may be helpful, whereas in deep seated AVMs, navigation may be required as an adjunct to confirm intra operative findings.

Multistage indocyanine green videoangiography for the convexity dural arteriovenous fistula with angiographically occult pial fistula

Recently, intraoperative indocyanine green (ICG) videoangiography has become a common technique for treating cerebrovascular diseases. We report a case of dural arteriovenous fistula (AVF) treated with direct surgery using intraoperative ICG videoangiography. A 41-year-old man with right hemiplegia caused by a left subcortical hemorrhage was transferred to our hospital. Digital subtraction angiography (DSA) revealed a left convexity parasagittal dural AVF. Surgical resection of the dural AVF was performed using step-by-step ICG videoangiography 4 times in each dissection procedure, which precisely delineated the structure of the dural AVF. After a circular incision of the dura around the fistular point, repeated ICG videoangiography identified the residual fistula between the pial artery from the middle cerebral artery and the draining vein. Complete disappearance of the AVF was confirmed by ICG videoangiography after this pial fistula was removed. Postoperative DSA revealed no residual AVF. Accurate detection of all fistular points and complete resection, including the dura mater and pial vessels, are necessary to avoid rebleeding caused by the residual dural AVF due to incomplete obliteration of the fistular points. Intraoperative ICG videoangiography could provide information on angiographically occult vascular malformation, such as pial fistulas, that cannot be detected by preoperative DSA. Our findings suggest that multistage intraoperative ICG videoangiography can be quite useful for complete resection of a dural AVF with angiographically occult pial fistula.

Indocyanine green videoangiography of optic cavernous angioma - case report -

The intraoperative findings of an indocyanine green videoangiography (ICG-VAG) study of a cavernous angioma located in the optic chiasm are reported. A 23-year-old Japanese man suddenly developed visual field loss, and magnetic resonance imaging suggested the presence of a suprasellar tumor in contact with the optic chiasm. Preoperative angiography did not clearly show any tumor shadow. Right fronto-temporal craniotomy was performed, and an aggregation of blood vessels was seen on the right surface of the optic chiasm. Cavernous angioma was suspected. ICG-VAG was begun 22 seconds after the beginning of contrast agent infusion via a peripheral blood vessel. The lesion remained unstained, although the brain surface, an artery superior to the optic nerve, and veins were visualized. The cavernous angioma was resected following surface coagulation. ICG-VAG is currently being evaluated for future application in the differential diagnosis based on imaging findings, and the present case provides an important example of intraoperative ICG-VAG imaging of an unoperated cavernous angioma.

Intraoperative magnetic resonance imaging in the successful surgical treatment of an arteriovenous malformation--case report

A 44-year-old female presented with left occipital arteriovenous malformation (AVM) manifesting as sudden onset of severe headache. Magnetic resonance (MR) imaging and conventional angiography showed the left occipital AVM with hemorrhage. Intraoperative MR imaging (iMR imaging) and intraoperative time-resolved imaging of contrast-kinetics (iTRICKS) at 1.5 T revealed complete removal of the nidus of the AVM without conventional catheter angiography. Conventional catheter angiography is commonly used in preoperative and intraoperative examination of AVMs, and for documentation of the surgical outcome, but less-invasive techniques are desirable for both preoperative screening and intraoperative examination. iMR imaging with iTRICKS is less invasive and safer than conventional angiography for both brain tumor surgery and AVM surgery.

Intraoperative angiography for cranial dural arteriovenous fistula

BACKGROUND AND PURPOSE

IA is a valuable adjunct during surgery for a variety of neurovascular diseases; however, there are no reported series describing IA for DAVFs. This study was undertaken to evaluate the safety and efficacy of IA for DAVFs.

MATERIALS AND METHODS

A retrospective review of DAVF surgical cases during a 20-year period was conducted, and cases with IA were evaluated. Clinical details, surgical and angiographic findings, and postoperative outcomes were reviewed. The incidence of residual fistula on IAs, the utility of the surgical procedure, and the incidence of false-negative findings on IA were also determined.

RESULTS

IA was performed in 29 patients (31 DAVFs) for DAVFs. The distribution of the fistulas was the following: transverse-sigmoid (n = 9), tentorial (n = 6), torcular (n = 3), cavernous sinus (n = 4), SSS (n = 4), foramen magnum (n = 3), and temporal-middle fossa (n = 2). Twelve patients had undergone prior embolization, while 6 patients had unsuccessful embolization procedures. Thirty-eight surgeries were performed for DAVF in 29 patients, and IA was performed in 34 surgeries. Forty-four angiographic procedures were performed in the 34 surgeries. Nine patients underwent multiple angiographies. In 11 patients (37.9%), IA revealed residual fistula after the surgeon determined that no lesion remained. This led to further exploration at the same sitting in 10 patients, while in 1 patient, further surgery was performed at a later date. False-negative findings on IA occurred in 3 patients (10.7%).

CONCLUSIONS

IA is an important adjunct in surgery for DAVF. In this series, it resulted in further surgical treatment in 37.9% of patients. However, there was a 10% false-negative rate, which justified subsequent postoperative angiography.

Intraoperative indocyanine green angiography for obliteration of a spinal dural arteriovenous fistula

Spinal dural arteriovenous fistulas (DAVFs) are the most common type of spinal arteriovenous malformation and are an important, underdiagnosed cause of progressive myelopathy and morbidity in patients with spine disorders. Successful microsurgical management of these lesions is dependent on the surgeon's ability to identify vessels of the fistula and to confirm its successful obliteration postintervention. Indocyanine green (ICG) fluorescent angiography is an emerging tool for delineating intraoperative vascular anatomy, and it has significant potential utility in the treatment of vascular disease in the spine. The authors present the case of a 76-year-old man with progressive and debilitating bilateral lower-extremity weakness and numbness on exertion, in whom a left T-8 spinal DAVF was diagnosed based on results of conventional spinal angiography. Unfavorable anatomy based on angiographic findings precluded endovascular embolization of the fistula, and the patient subsequently underwent T7-9 bilateral laminectomies for microsurgical clip occlusion. Intraoperative ICG fluorescent angiography was used before clip placement to identify the arterialized veins of the fistula, and after clip placement to confirm obliteration of the fistulous connection and restoration of normal blood flow. Intraoperative ICG angiography serves an important role in the microsurgical treatment of DAVF. It can be used to map the anatomy of the fistula in real time during surgery and to verify fistula obliteration rapidly after clip placement. This report adds to the growing body of literature demonstrating the importance of ICG angiography in vascular neurosurgery of the spine.