Indocyanine Green Videoangiography Research Articles

Intraoperative blood flow monitor for aneurysm clipping

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.

Robotic-Assisted Resection of Pelvic Arteriovenous Malformation Utilising Intraoperative Video Angiography with Indocyanine Green

<h3>Study Objective</h3> Surgical resection of pelvic arteriovenous malformations (AVM) can be challenging, and pre-operative imaging may not clearly identify feeding vessels. We describe a case of pelvic AVM in a young woman and demonstrate the robotic surgical resection utilising video angiography with indocyanine green (ICG). <h3>Design</h3> Case report and surgical video. <h3>Setting</h3> Four-arm robotic assisted laparoscopy. <h3>Patients or Participants</h3> A nullipara with pelvic AVM. <h3>Interventions</h3> Robotic-assisted resection of pelvic AVM guided by intraoperative ICG angiography. <h3>Measurements and Main Results</h3> A 22-year-old woman presented with progressively worsening left pelvic pain. Pelvic ultrasound demonstrated a 7cm left adnexal vascular mass and magnetic resonance angiogram confirmed a left pelvic AVM. The patient was counselled regarding the risks of embolization versus surgery and decided on the latter. Using a robotic surgical system, the left pelvic side wall was opened at the pelvic brim and careful dissection of the retroperitoneal alveolar tissue was performed. 3mL of a 2.5mg/mL solution of ICG was injected peripherally, followed by 10mL bolus of normal saline. Using the near infra-red imaging of the robotic system, the ICG demonstrates small efferent vessels arising from the left ovarian vessels and a large vein communicating with the left external iliac vein. Vascular clips were applied to the aberrant vein prior to ligation. The AVM was carefully dissected away from the surrounding tissues, with use of bipolar diathermy for coagulation of smaller vessels. A further dose of ICG was injected after resection to ensure haemostasis and to confirm the perfusion of remaining organs. Mesosalpinx and pelvic side wall peritoneum were closed with 2-0 barbed suture. The patient was discharged the following day with complete resolution of left pelvic pain and normal pelvic ultrasound scan 6 weeks later. <h3>Conclusion</h3> Robotic surgical resection of pelvic AVM is enhanced with guidance from intraoperative ICG video angiography to ensure haemostasis and complete excision.

Numerical Model for Cerebrovascular Hemodynamics with Indocyanine Green Fluorescence Videoangiography.

The use of indocyanine green videoangiography (ICG-VA) to assess blood flow in the brain during cerebrovascular surgery has been increasing. Clinical studies on ICG-VA have predominantly focused on qualitative analysis. However, quantitative analysis numerical modelling for time profiling enables a more accurate evaluation of blood flow kinetics. In this study, we established a multiple exponential modified Gaussian (multi-EMG) model for quantitative ICG-VA to understand accurately the status of cerebral hemodynamics. We obtained clinical data of cerebral blood flow acquired the quantitative analysis ICG-VA during cerebrovascular surgery. Varied asymmetric peak functions were compared to find the most matching function form with clinical data by using a nonlinear regression algorithm. To verify the result of the nonlinear regression, the mode function was applied to various types of data. The proposed multi-EMG model is well fitted to the clinical data. Because the primary parameters-growth and decay rates, and peak center and heights-of the model are characteristics of model function, they provide accurate reference values for assessing cerebral hemodynamics in various conditions. In addition, the primary parameters can be estimated on the curves with partially missed data. The accuracy of the model estimation was verified by a repeated curve fitting method using manipulation of missing data. The multi-EMG model can possibly serve as a universal model for cerebral hemodynamics in a comparison with other asymmetric peak functions. According to the results, the model can be helpful for clinical research assessment of cerebrovascular hemodynamics in a clinical setting.

Indocyanine Green Administration May Cause an Exaggerated Peripheral Oxygen Desaturation in the Presence of Liver Disease—An Underemphasized Observation

Microscope-integrated indocyanine green video angiography (ICG-VA) is used to assess the completeness of clipping and cerebral vascular flow during aneurysm surgery.[1] It is a more practical and less time-consuming alternative to intraoperative digital subtraction angiography (DSA). ICG has been reported to cause a decrease in peripheral oxygen saturation (SpO2).[2] [3] [4]

Endoscope-integrated indocyanine green video angiography and the detection of the fragile periventricular collaterals associated with moyamoya disease: illustrative cases

Hemorrhagic moyamoya disease (MMD) and the fragile periventricular collaterals are known to have a causal relationship. Digital subtraction angiography and magnetic resonance angiography have shown the presence of fragile periventricular moyamoya vessels. However, dynamic fragile periventricular moyamoya vessels have never been observed under direct vision. The authors treated two patients with hemorrhagic MMD: a 42-year-old man with intraventricular hemorrhage and a 47-year-old woman with intracerebral hemorrhage. Endoscope-integrated indocyanine green video angiography (EICG angiography) could visualize the dynamic fragile periventricular collaterals. In particular, EICG angiography enabled visualization of invisible moyamoya vessels buried in the subependyma and characterization of the blood flow in the moyamoya vessels located inside the lateral ventricles and hematoma cavity. EICG angiography can confirm the fragile periventricular collaterals associated with MMD by direct visualization. The high spatial resolution and real-time imaging can help to avoid accidental hemorrhage in and after evacuation of hemorrhage in patients with MMD.

Trimming of Facial Artery Myomucosal Flap (FAMM) using Indocyanine Green Fluorescence Video-Angiography: Operative Nuances.

Facial artery myomucosal flap (FAMM) is an intraoral flap pedicled on facial artery used for reconstruction of oral/oropharyngeal defects.1 Careful assessment of perfusion is essential to avoid flap necrosis, and several options are used for this purpose. Among these, indocyanine green (ICG) fluorescence video-angiography (ICG-VA) represents an innovative tool whose adoption in flap surgery is still at its early days.2 METHODS: In this multimedia article, we described the use of ICG-VA for perfusion assessment of a FAMM flap harvested for reconstruction of oral lining after ablation of a cT2cN0 floor-of-mouth (FOM) cancer. The use of ICG-VA was aimed at defining ischemic areas on the flap according to a flap-to-normal mucosa ICG ratio. After transoral excision of the FOM cancer and subsequent harvesting of a FAMM flap, we used ICG-VA to intraoperatively assess its perfusion. The degree of flap perfusion was expressed point-by-point through flap-to-normal mucosa ICG ratio (percentage); a value of 25-27% was considered as threshold for ischemia.3 Perfusion was documented both with white light modality with "overlay fluorescence" and "black and white SPY fluorescence mode" designed to increase the sensitivity of ICG detection. Small, ischemic areas were detected in the distal part of the flap and were trimmed. At the end of the procedure, an adequate perfusion was evident throughout the whole flap, allowing its safe insetting for left FOM reconstruction. Postoperative course was uneventful. ICG-VA represents a reliable tool for intraoperative detection-and trimming-of ischemic areas on reconstructive flaps.

Strategies for Treatment of Multiple Brain Aneurysms Without Intraoperative Adjuncts

Although fairly rare, multiple brain aneurysms are well known to occur in certain conditions such as arteriovenous malformations, coarctation of the aorta, renal artery stenosis, adult type 3 polycystic kidney disease, as well as connective tissue disorders (such as Ehlers-Danlos syndrome, Marfan syndrome, and fibromuscular dysplasia). Increased incidence of complications of surgery in such situations is expected to be more likely than in surgery for a single aneurysm, particularly in the absence of intraoperative guidance with adjuncts. We report a case of an anterior communicating artery aneurysm, a right middle cerebral artery aneurysm, and a right pericallosal aneurysm in a 70-year-old man. All 3 aneurysms were clipped through a single-stage approach without the aid of any adjuncts such as micro-Doppler ultrasonography, indocyanine green videoangiography, or intraoperative digital subtraction angiography. We carried out a literature review for past publications on similar reports. The patient made a complete postoperative recovery and sustained no neurologic deficits. Out of 388 publications from the literature search, only 1 case report described clipping of 2 tandem aneurysms in a 60-year-old woman without mentioning any intraoperative adjuncts. This case illustrates that multiple aneurysms can actually be safely operated with adequate planning in the absence of these adjuncts, especially in resource-poor regions. This is particularly crucial in Africa and most low-and-middle-income countries, where such facilities and equipment are not common.

Comparison of Intraoperative Indocyanine Green Videoangiography vs Postoperative Catheter Angiography to Confirm Microsurgical Occlusion of Spinal Dorsal Intradural Arteriovenous Fistulas.

Dorsal intradural arteriovenous fistulas (DI-AVFs) represent 80% of spinal AVFs. Microsurgical clip occlusion is a durable treatment that uses preoperative and postoperative digital subtraction angiography (DSA) as standard practice. Intraoperative indocyanine green videoangiography (ICG-VA) is a valuable intraoperative adjunct in these cases. Intraoperative ICG-VA findings have not been compared with postoperative DSA findings. To assess the diagnostic value of intraoperative ICG-VA vs postoperative DSA for spinal DI-AVFs. A multi-institutional database of vascular malformations was queried for all surgically managed cases of DI-AVF. Patients with both intraoperative ICG-VA and postoperative DSA were included. Demographic and radiologic data, intraoperative findings, and surgical outcomes data were retrospectively analyzed. Forty-five patients with DI-AVF were identified (male sex, 32; mean age, 61.9 [range, 26-85] years). All DI-AVFs were treated with interruption of the fistula with clip occlusion of the draining vein. Intraoperative ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 40 patients and confirmed complete obliteration in all patients. The negative predictive value of ICG-VA confirming complete occlusion of the DI-AVFs was 100%. Eighteen patients (47%) experienced clinical improvement, and 16 (42%) experienced no change in condition. ICG-VA is useful for intraoperative identification of DI-AVFs and confirmation of complete microsurgical occlusion. Correlation between intraoperative ICG-VA and postoperative DSA findings demonstrates the diagnostic power of ICG-VA. This finding suggests that postoperative DSA is unnecessary when intraoperative ICG-VA confirms complete occlusion of the DI-AVF, which will spare patients the procedural risk and cost of this invasive procedure.

Insufficient Closing Forces of Yasargil Titanium Clips in Two Small Aneurysms Detected with Intraoperative Indocyanine Green Videoangiography.

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. 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. 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. 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.

Pseudo-residual nidus after arteriovenous malformation surgery: illustrative case

BACKGROUNDIntraoperative indocyanine green video angiography (ICG-VA) is useful for determining the extent of lesion removal during cerebral arteriovenous malformation (AVM) surgery. The authors described a case of surgical removal of an AVM presenting with early venous filling mimicking a residual nidus on intraoperative ICG-VA.OBSERVATIONSA 7-year-old girl experienced a sudden disturbance of consciousness. Computed tomography revealed right frontal intracerebral hemorrhage. Digital subtraction angiography showed a Spetzler-Martin grade 1 AVM in the right frontal lobe. The patient received surgical removal of the AVM after endovascular embolization. After removal of the nidus, the first intraoperative ICG-VA revealed early venous filling of the cortex around the excision cavity. Additional resection of the cortex around this area was performed. Histopathological examination of the lesion revealed a dilated normal vascular structure without an AVM.LESSONSEarly venous filling in the surrounding brain tissue after AVM removal does not necessarily indicate a residual nidus. The need for additional resection of the lesion depends on the eloquence of the area.

Role of Indocyanine Green with FLOW 800 in Removal of Hidden Arteriovenous Malformations

Indocyanine green videoangiography (ICG-VA) with FLOW 800 (Carl Zeiss AG) has been used as a visualization tool to guide arteriovenous malformation (AVM) surgery since 2011. We performed a systematic review and evaluated the quality of evidence available on this topic. In addition, we present a series of our own cases demonstrating the unique use of ICG-VA in the localization and removal of deeper seated AVMs. Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines for systematic reviews, we identified studies related to ICG-VA with FLOW 800 in AVM surgeries using search terms. The studies were screened and reviewed, and the quality of evidence was analyzed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria. We performed a retrospective review of our own cases of AVM removal with ICG-VA and FLOW800. Our search revealed 27 relevant studies, 17 of which met our inclusion criteria. The quality of the body of evidence was determined to be "very low" using the GRADE criteria. We used ICG-VA with FLOW 800 analysis for 14 cases of microsurgical AVM removal. This technique provided unique insights into the localization of deep seated AVMs in 8 cases (57%). No residual AVM was found when assessed by the 6-month follow-up angiogram. We present cases highlighting the usefulness of this technique for the localization of certain AVMs. We believe the use of ICG-VA can guide the removal of deeper seated AVMs, because it can reveal surface feeders and draining veins that can be followed to a hidden nidus. Larger, registry-based studies are needed to confirm these findings and improve the overall quality of evidence.

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

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

Head and neck pedicled flap autonomization using a new high-resolution indocyanine green fluorescence video-angiography device.

In head and neck oncologic surgery a reconstructive phase is often required and pedicled flaps are still a viable option, though they may need a pedicle division performed at a later stage. Several techniques are commonly used for perfusion assessment of the flaps, with indocyanine green (ICG) fluorescence video‐angiography representing a promising tool. We used ICG video‐angiography to evaluate the perfusion of two of the most commonly adopted pedicled flaps in the head and neck field (the supraclavicular and the paramedian forehead flap) before and after second‐stage pedicle division, allowing a safer in‐setting. Moreover, the new high‐resolution device that we have employed added further accuracy to the traditional video‐angiography, providing a real‐time flap‐to‐normal skin ICG ratio. Indeed, ICG video‐angiography proved to be a useful tool in head and neck reconstructive surgery and it may allow an earlier second‐stage pedicle division.

Utility of indocyanine green videoangiography with FLOW 800 analysis in brain tumour resection as a venous protection technique

BackgroundIn regard to central nervous system tumour resection, preserving vital venous structures to avoid devastating consequences such as brain oedema and haemorrhage is important. However, in clinical practice, it is difficult to obtain clear and vivid intraoperative venous visualization and blood flow analyses.MethodsWe retrospectively reviewed patients who underwent brain tumour resection with the application of indocyanine green videoangiography (ICG-VA) integrated with FLOW 800 from February 2019 to December 2020 and present our clinical cases to demonstrate the process of venous preservation. Galen, sylvian and superior cerebral veins were included in these cases.ResultsClear documentation of the veins from different venous groups was obtained via ICG-VA integrated with FLOW 800, which semiquantitatively analysed the flow dynamics. ICG-VA integrated with FLOW 800 enabled us to achieve brain tumour resection without venous injury or obstruction of venous flux.ConclusionsICG-VA integrated with FLOW 800 is an available method for venous preservation, although further comparisons between ICG-VA integrated with FLOW 800 and other techniques of intraoperative blood flow monitoring is needed.

Coexistence of anterior cranial fossa dural arteriovenous fistula and arteriovenous malformation with the same drainage system: illustrative case

BACKGROUNDThe authors report a rare case of coexistence of dural arteriovenous fistula (DAVF) and arteriovenous malformation (AVM), with a common trunk drainer from both DAVF and AVM in the left anterior cranial fossa (ACF) with simple DAVF in the right ACF.OBSERVATIONSA 63-year-old female presented with seizure. Cerebral angiography showed bilateral DAVFs in the ACF and AVM in the left frontal lobe. A dilated frontal vein acted as a simple drainer of the right DAVF. In contrast, a dilated vein with large varix was the common drainer of both the left DAVF and the AVM. During surgery, indocyanine green videoangiography was performed with direct observation. In the left ACF, the drainer occlusion of the DAVF resulted in partial shrinkage of the varix and decreased distal blood flow. Additional main feeder occlusion of the AVM could decrease the blood flow further, but not completely because of the residual pial supplies for the AVM. Finally, the nidus of the AVM with varix was removed by en bloc resection.LESSONSNeurosurgeons should be aware of the coexistence of DAVF and AVM with a common trunk drainer. Only simple occlusion of the drainer from DAVF is not sufficient, so removal of the AVM is essential.

How do I: Venous reconstruction of accidentally injured superficial sylvian vein during the clipping of an unruptured cerebral aneurysm.

The transsylvian approach is a versatile treatment method for aneurysms of the anterior circulatory system. Studies have shown that sylvian veins run in various patterns, suggesting the need for dissection between veins to obtain appropriate surgical corridor. In case of inadvertent sylvian vein injury, serious complications such as venous congestion may occur. We herein describe the "side-to-side anastomosis reconstruction technique" of the resected superficial sylvian vein. This technique can be effective for the reconstruction of other cortical veins, and indocyanine green videoangiography was effective in determining the indications for venous reconstruction.

809 Comparison of Intraoperative Indocyanine Green Videoangiography Versus Postoperative Catheter Angiography to Confirm Microsurgical Occlusion of Dorsal Intradural Arteriovenous Fistulas

INTRODUCTION: Dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular malformations and 80% of all spinal AVFs. Microsurgical clip occlusion is a durable treatment for DI-AVFs and includes pre- and postoperative digital subtraction angiography (DSA) as the standard practice. Intraoperative indocyanine green videoangiography (ICG-VA) has become a valuable intraoperative adjunct in these cases. Results with intraoperative ICG-VA have not been compared to postoperative DSA. METHODS: A multi-institutional database of vascular malformations was queried for all surgically managed cases of DI-AVFs. Patients with both intraoperative ICG-VA and postoperative DSA were included. Demographic, radiologic, intraoperative findings, and surgical outcomes data were obtained and retrospectively analyzed. RESULTS: Forty-five cases of DI-AVFs were identified. Patients had a mean age of 61.9 years old (range 26-85), including 32 males and 13 females. Except for one asymptomatic patient, all other patients presented with leg numbness and weakness, gait instability, bowel and/or bladder incontinence, back pain, paresthesias, paraplegia, upper extremity discoordination, erectile dysfunction, and/or general weakness. The majority of lesions were diagnosed in the thoracic spine (72%). All DI-AVFs were treated with interruption of the fistula with clip occlusion of the draining vein. Intraoperative ICG-VA confirmed complete obliteration in all patients. Postoperative spinal angiography was performed on 40 patients confirming complete obliteration in all patients. More patients had clinical improvement compared to their preoperative state than stayed the same (47.4% vs. 42.1%). CONCLUSIONS: ICG-VA is useful for both intraoperative identification of DI-AVFs and confirmation of complete microsurgical occlusion. Perfect correlation between intraoperative ICG-VA and postoperative DSA demonstrates the diagnostic power of the former. This finding suggests that postoperative DSA is not necessary when intraoperative ICG-VA confirms complete occlusion of the DI-AVF, which will spare patients the procedural risk and cost of this invasive procedure.

Commentary: Subclavian Artery Flow Dynamics Evaluated by Analytical Intraoperative Indocyanine Green Videoangiography During Surgical Treatment of Thoracic Outlet Syndrome: Case Series.

Department of Neurosurgery and Neurorestoration, Klinikum Klagenfurt, Klagenfurt (Carinthia), Austria Correspondence: Thomas Kretschmer, MD, PhD, Abteilung für Neurochirurgie und Neurorestauration Klinikum Klagenfurt Feschnigstr, 11 A-9020, Klagenfurt, Austria. Email: [email protected]

Deep-Learning-Based Cerebral Artery Semantic Segmentation in Neurosurgical Operating Microscope Vision Using Indocyanine Green Fluorescence Videoangiography

There have been few anatomical structure segmentation studies using deep learning. Numbers of training and ground truth images applied were small and the accuracies of which were low or inconsistent. For a surgical video anatomy analysis, various obstacles, including a variable fast-changing view, large deformations, occlusions, low illumination, and inadequate focus occur. In addition, it is difficult and costly to obtain a large and accurate dataset on operational video anatomical structures, including arteries. In this study, we investigated cerebral artery segmentation using an automatic ground-truth generation method. Indocyanine green (ICG) fluorescence intraoperative cerebral videoangiography was used to create a ground-truth dataset mainly for cerebral arteries and partly for cerebral blood vessels, including veins. Four different neural network models were trained using the dataset and compared. Before augmentation, 35,975 training images and 11,266 validation images were used. After augmentation, 260,499 training and 90,129 validation images were used. A Dice score of 79% for cerebral artery segmentation was achieved using the DeepLabv3+ model trained using an automatically generated dataset. Strict validation in different patient groups was conducted. Arteries were also discerned from the veins using the ICG videoangiography phase. We achieved fair accuracy, which demonstrated the appropriateness of the methodology. This study proved the feasibility of operating field view of the cerebral artery segmentation using deep learning, and the effectiveness of the automatic blood vessel ground truth generation method using ICG fluorescence videoangiography. Using this method, computer vision can discern blood vessels and arteries from veins in a neurosurgical microscope field of view. Thus, this technique is essential for neurosurgical field vessel anatomy-based navigation. In addition, surgical assistance, safety, and autonomous surgery neurorobotics that can detect or manipulate cerebral vessels would require computer vision to identify blood vessels and arteries.

Subclavian Artery Flow Dynamics Evaluated by Analytical Intraoperative Indocyanine Green Videoangiography During Surgical Treatment of Thoracic Outlet Syndrome: A Case Series.

Indocyanine green (ICG) videoangiography is rarely used during the surgical treatment of thoracic outlet syndrome (TOS). To evaluate subclavian artery (SA) flow dynamics using the analytical ICG videoangiography during TOS surgeries. We examined patients with neurogenic TOS who received surgical treatment and whose SA blood flow at the interscalene space was evaluated using ICG videoangiography equipped with an analytical function (FLOW800). Anterior scalenectomy with or without middle scalenectomy and first rib resection were conducted for decompression of the brachial plexus. ICG videoangiography was performed before and after decompression of the brachial plexus. After acquisition of grayscale and color-coded maps, a region of interest was placed in the SA to obtain time-intensity diagrams. Maximum intensity (MI), rise time (RT), and blood flow index (BFi) were calculated from the diagram, in arbitrary intensity (AI) units. We compared values before and after decompression. Comparisons of the three parameters before and after decompression were assessed statistically using the paired t-tests and Wilcoxon signed-rank test. We evaluated nine procedures in consecutively presenting patients. The observed mean values of MI, RT, and BFi before decompression were 174.1 ± 61.5 AI, 5.2 ± 1.1 s, and 35.2 ± 13.5 AI/s, respectively, and the observed mean values of MI, RT, and BFi after decompression were 299.3 ± 167.4 AI, 6.6 ± 0.8 s, and 44.6 ± 28.3 AI/s, respectively. These parameters showed higher values after decompression than before decompression, and the increase in MI and RT was statistically significant (P < .05). ICG videoangiography allows semiquantitative evaluation of hemodynamic changes during TOS surgery. A marked decrease in the velocity of SA flow was observed after decompression.