STA-MCA Bypass Surgery Research Articles

Analysis of rescue strategies for acute thrombosis during STA-MCA bypass surgery and the literature review

Background and objectivesSTA-MCA bypass surgery is mainly used for Moyamoya disease, giant intracranial aneurysms, and resection of intracranial tumors requiring sacrifice of blood vessels. The intraoperative patency of the reconstructive vessels is critical to the efficacy of the procedure. This study aimed to evaluate the efficacy of intra-arterially infused tirofiban for the treatment of acute thrombosis during STA-MCA bypass surgery and countermeasures for acute thrombosis.MethodsThis study involved 209 patients (272 hemispheres) who underwent STA-MCA surgery between November 2020 and December 2023. Intraoperative acute thrombosis occurred in eight patients (3.83%,8 hemispheres). We retrospectively reviewed the clinical and imaging data, surgical procedure, and follow-up outcomes of eight patients. We implemented the different thrombolytic methods to evaluate the optimal thrombosis management during the bypass surgery. After three months, we assessed neurological functions using the modified Rankin Scale (mRS) and conducted a literature review using PubMed.ResultsEight patients (four male patients and four female patients) developed acute thrombosis during the bypass surgery. Of the eight patients, two underwent re-anastomosis after thrombus removal, three received local injections of tirofiban into the anastomosis or the branches of the superficial temporal artery, and three underwent superselective intra-arterial tirofiban infusion using a microcatheter. Thrombosis were resolved, and arteries were recanalized in all patients. The mRS score was 0 in all patients. No major ischemic or hemorrhagic complications occurred.ConclusionOur treatment methods were efficacious in the management of acute thrombosis. Intra-arterial tirofiban administration seems to be a simple and effective treatment option for acute thrombosis during STA-MCA bypass surgery.

Assessing donor-recipient arterial pressure dynamics in STA-MCA bypass for moyamoya disease

BackgroundIn bypass surgery for moyamoya disease (MMD), the superficial temporal artery’s (STA) pressure needs to surpass that of the cortical M4 recipient of the middle cerebral artery (MCA), boosting cerebral blood flow into the MCA and enhancing cerebral circulation. This study investigates the STA-MCA arterial pressure parameters and gradients during bypass surgery, aiming to deepen our understanding of hemodynamic shifts pre- and post-operation.MethodsDSA imaging data were prospectively collected from patients diagnosed with bilateral MMD who underwent STA-MCA bypass surgery between 2022 and 2023 and stratified according to the Suzuki stage. The mean arterial pressure (MAP) of the donor and recipient arteries was directly measured during the STA-MCA bypass procedure, and these data were statistically analyzed and evaluated.ResultsAmong 48 MMD patients, Suzuki grading revealed that 43.8% were in early stages (II and III), while 56.2% were in advanced stages (IV, V, and VI). Predominantly, 77.1% presented with ischemic-type MMD and 22.9% with hemorrhagic type. Pre-bypass assessments showed that 62.5% exhibited antegrade blood flow direction, and 37.5% had retrograde. The mean recipient artery pressure was 35.0 ± 2.3 mmHg, with a mean donor-recipient pressure gradient (δP) of 46.4 ± 2.5 mmHg between donor and recipient arteries. Post-bypass, mean recipient artery pressure increased to 73.3 ± 1.6 mmHg. No significant correlation (r = 0.18, P = 0.21) was noted between δP and Suzuki staging.ConclusionOur study elucidated that cerebral blood pressure significantly decreases beyond the moyamoya network at the distal M4 segment. Furthermore, we observed bidirectional flow in MCA territories and a significant positive pressure gradient between the STA and M4 segments. The lack of correlation between Suzuki stages and M4 pressures indicates that angiographic severity may not reflect hemodynamic conditions before surgery, highlighting the need for customized surgical approaches.

Hemodynamic Effects of Tortuosity and Stenosis in Superficial Temporal Artery-Middle Cerebral Artery Bypass for Moyamoya Disease

BackgroundSuperficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery has been widely adopted in treating moyamoya disease (MMD). Geometric variations including high tortuosity and stenosis appear in many cases but the hemodynamic effects have not been comprehensively evaluated. AimWe aim to evaluate the hemodynamic effects of bypass geometry variations based on patient-specific data. Methods17 patients with MMD underwent STA-MCA bypass surgery with highly tortuous bypass geometry were included. For each patient, the original 3-dimensional structure of STA-MCA bypass was reconstruct from clinical imaging data. The bypass structure was virtually improved by removing the tortuosity and stenosis. Computational fluid dynamics (CFD) simulation was performed on both bypass structures under identical patient-specific condition. The simulated hemodynamic parameters of the bypass and its distal branches were compared between the original and virtually improved bypass geometries in all cases using paired t-test or Wilcoxon signed-rank test. The changes of hemodynamic parameters were compared between the cases with and without mild-to-moderate stenosis (44.0%-70.3% in diameter) in the bypass using t-test or Mann-Whitney U test. ResultsThe virtual improvement of bypass geometry significantly increased the flow rate of the bypass and its distal branches (p<0.05) and decreased the transcranial flow resistance (p<0.05). The hemodynamic changes in cases with stenosis removal were significantly higher than those without stenosis (p<0.05). ConclusionHigh tortuosity and stenosis can significantly change the hemodynamics of STA-MCA bypass, and the optimization of bypass geometry deserves further consideration.

Various Bypass Surgery:Preoperative Simulation for STA-MCA Bypass

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform®BRAIN LAB)and the 3DCG simulation software GRID®Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.

Pearls and pitfalls in double-barrel STA-MCA bypass surgery for cerebral ischemia

Pearls and pitfalls in double-barrel STA-MCA bypass surgery for cerebral ischemia

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.

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. 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. 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. 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.

Optimizing the Approach to STA-MCA Bypass Surgery and Reducing Wound Complications

The treatment of complex intracranial aneurysms with bypass surgery using 2 branches of the superficial temporal artery (STA) proves to be an effective surgical option. However, the harvest of these 2 STA branches, combined with a pterional craniotomy, carries the potential risk of delayed wound healing of the skin flap. This study undertook a retrospective analysis to examine and identify the factors associated with this delayed wound healing. A total of 56 consecutive cases, including both ruptured and unruptured complex intracranial aneurysms, that underwent bypass surgery with 2 branches of the STA, were analyzed retrospectively. Major delayed wound healing was observed in 6 (10.7%) cases. Univariate analysis demonstrated significant associations with the following factors: rupture (P= 0.023), presence of diabetes mellitus (P= 0.028), large craniotomy size (P= 0.012), and the type of skin incision (P ≤ 0.001). Age (P= 0.283), sex (P= 0.558), body mass index (P= 0.221), and other blood test parameters did not demonstrate any statistical significance. Similarly, the presence of a dominant frontal branch (P= 0.515) or a low-positioned frontal branch (P= 0.622) did not reveal statistically significant results. In the treatment of complex intracranial aneurysms, where harvesting of the 2 STA branches is involved with a pterional craniotomy, producing a smaller skin flap (L- or T-shaped incision) is effective in minimizing the risk of delayed wound healing. The process of harvesting the STA and closing the wound demands meticulous care, taking into consideration the normal anatomical structures and the subdermal vascular plexus of the scalp.

Aneurysm appearing at the anastomosis site 11 years after superficial temporal artery–middle cerebral artery bypass surgery: moyamoya disease with a rapidly growing aneurysm. Illustrative case

BACKGROUND Superficial temporal artery–middle cerebral artery (STA-MCA) bypass surgery is performed to prevent ischemia and hemorrhage in patients with moyamoya disease. Only a few reports have described aneurysms appearing around the anastomosis site after bypass surgery, and the underlying mechanism remains unknown. OBSERVATIONS The present case involved a 62-year-old woman who underwent STA-MCA bypass surgery for ischemic quasi-moyamoya disease at 46 years of age. Postoperatively, she underwent annual magnetic resonance imaging examinations. At 11 years after STA-MCA bypass surgery, a 3-mm aneurysm appeared at the anastomosis site. Four years later, headache developed and the aneurysm had grown to 5 mm. Craniotomy clipping was performed to prevent rupture. The patient was discharged home 2 weeks after surgery without any apparent complications. LESSONS Long-term observation is crucial after direct bypass surgery for moyamoya disease. Measures to prevent rupture should be considered for cases involving aneurysm complications.

Superficial Temporal Artery-Middle Cerebral Artery Bypass Combined with Internal Carotid Ligation in Treating Complex Internal Carotid Aneurysms. The Willis Polygon Score is an Effective Solution for Developing Countries

Internal carotid complex aneurysms (ICCAs) management is challenging. Ligating the internal carotid artery (ICA) combined with Superficial Temporal Artery-Middle Cerebral Artery (STA-MCA) anastomosis is an effective treatment option. Balloon test occlusion (BTO) assessments for preoperative decision-making are unaffordable in developing countries. This article discusses the study of Willis polygon (WP) segments as an option and suggests a score for decision-making. Herein, we report the outcomes of a series of patients treated for ICCA aneurysms at a single institution. From September 2016 to December 2020, we conducted a retrospective cohort study that analyzed data from patients with ICCAs. Among them, 9 patients received treatment involving ICA ligation combined with STA-MCA anastomosis. Partial or total carotid ligation was determined by using the WP score (WPS). All Patients underwent STA-MCA anastomosis, in addition to total ICA ligation in 7 patients and partial ICA ligation in 2 patients with a WPS of 7 and 5, respectively. Patients with partially ligated carotid arteries were referred to an overseas neurointerventional center 12months after surgery. As the BTO test was negative, they underwent ICA occlusion by coiling. Postoperative clinical outcomes did not change in 8/9 patients. In 1 patient, we reported a minor parietal stroke; the patient recovered completely after 6months. Total aneurysm exclusion by thrombosis was achieved in 7/9 patients after total ICA ligation alone and in 2/9 patients after partial ICA ligation combined with coiling. Limited access to endovascular assessment techniques such as BTO poses challenges in managing ICCAs. The WPS for decision-making appears to be a simple and safe option. In addition to STA-MCA bypass surgery, total or partial ICA ligation may be proposed depending on the WPS. After 12months, patients with low WPS who underwent partial ICA ligation combined with bypass had postoperative normal BTO.

Complementary role of Indocyanine green video angiography, dual-image video angiography and flow-800

Background Visualization of cerebral vessels, their branches and the surrounding structures are essential during cerebrovascular surgery. Indocyanine green dye-based video angiography is a commonly used technique in cerebrovascular surgery. This paper aims to analyze the real-time imaging of ICG-AG, DIVA, and the use of ICG-VA with Flow 800 to compare their usefulness in surgery. Methods Intraoperative real-time identification of vascular and surrounding structures in twenty nine anterior circulation aneurysms and three posterior circulation aneurysm clipping, one STA-MCA bypass, and two carotid endarterectomies were performed in patients using ICG-VA alone, DIVA, ICG-VA with Flow 800 to analyze and compare each of these methods in details. Results ICG-VA and DIVA couldn’t visualize perforators in twenty-three cases of cerebral aneurysms clipping when used alone. Compared to that by adding Flow 800 perforators were easily visualized. In three cases, occlusion of perforators after clip application was visualized by DIVA and solved by repositioning surgical clips. In one STA-MCA bypass surgery, adequate blood flow to cortical branches of MCA (M4) from STA branches was assessed with ICG-VA, DIVA, and the use of ICG-VA with Flow 800 color mapping. ICG-VA, DIVA, and Flow 800 observed the lack of blood flow and fluttering atherosclerotic plaques in carotid endarterectomy. In one case of basilar tip aneurysm, we used ICG-VA with Flow 800; the intensity diagram drawn after determining regions of interest showed that there was no flow within the aneurysm sac after clipping. Conclusion In real-time surgery, a multimodal approach using ICG-VA, DIVA, and ICG-VA with Flow 800 colour mapping can serve as useful tools for better visualization of vascular and surrounding structures. The benefits of flow 800 color mapping, such as determining regions of interest, intensity diagrams, and color-coded images, outweigh the advantages over the ICG-VA and DIVA in the visualization of critical vascular anatomy in humans during surgical procedures.

Microsurgical Clipping of Giant Saccular Middle Cerebral Artery Aneurysm: A Case Report

Giant saccular middle cerebral artery aneurysm is rare vascular lesion and few cases have been reported in the literature. Microsurgical clipping is applied to treat a giant middle cerebral artery aneurysm .A 26 year-male presented with complain severe headache, multiple episodes of vomiting and one episode of sudden loss conscious since few hours prior to admission at emergency department. Cerebral Angiography showed a giant saccular middle cerebral artery (MCA) aneurysm. A standard right pterional approach applied to expose MCA and microsurgical clipping was performed. No any serious neurological complication was noted after surgery except right facial palsy. Patient was discharged at the 12th day of surgery.Endovascular therapy as well as STA-MCA bypass surgery plus clipping are usually applied to manage the giant MCA aneurysm. However, alone microsurgical clipping is also effective and has better result.

Superficial temporal artery-middle cerebral artery bypass for moyamoya disease treatment in Vietnam: A single-center prospective study

ObjectiveMoyamoya disease (MMD) is a rare progressive chronic cerebrovascular disease. There has been a lack of data on clinical characteristics and long-term outcomes in the treatment of MMD in Vietnam. Therefore, this study aims to investigate the clinical presentation of MMD in Vietnamese people as well as outcomes and complications during superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery. MethodsThis single-center, prospective case series of MMD was conducted from January 2015 to December 2021 at the Department of Neurosurgery, University Medical Center at Ho Chi Minh City (UMC HCMC). Clinical characteristics, imaging, and modified Rankin Scale (mRS) of the patients were recorded preoperatively. We analyzed the surgical complications, postoperative mRS, patency of STA-MCA bypass, free TIA/stroke time after surgery, improvement of symptoms as well as quality of life at 6 months and 12 months after STA-MCA bypass surgery. Results39 patients with 55 bypass procedures (61.5% male, mean age 44.1 ± 13.9 years) were enrolled. At 3-month follow-up, all STA-MCA bypasses were patent. The surgical morbidity rate and mortality rate were noted at 3.6% and 0% per treated hemisphere, respectively. 94.87% of patients improved in their quality of life after surgery. Reduces in TIA symptom and headache were reported in 97% and 90% of cases, respectively. There was a statistically significant improvement in clinical status after 12 months of follow-up compared with that before surgery, as measured by mRS (0.97 ± 1.203 vs 2.33 ± 1.108). Good preoperative clinical condition (mRS ≤ 2) was noted as an important factor affecting the surgical outcomes. ConclusionsRevascularization surgery in patients with MMD is a safe and effective procedure. STA-MCA bypass surgery may improve the clinical status, reduce TIA/stroke event and improve the quality of life in MMD patients. Our findings suggest that it may be indicated for treatment of symptomatic MMD.

Basic Procedures of STA-MCA Bypass Surgery Based on Right and Left Handling

Basic Procedures of STA-MCA Bypass Surgery Based on Right and Left Handling

Cross-Comparison of 4-Dimensional Flow Magnetic Resonance Imaging and Intraoperative Middle Cerebral Artery Pressure Measurements Before and After Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery.

The hemodynamic changes after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery are unclear. To clarify the hemodynamics by comparing flow parameters obtained by 4-dimensional (4D) flow magnetic resonance imaging (MRI) and intraoperative MCA pressure measurement. We recruited 23 patients who underwent STA-MCA bypass surgery for internal carotid artery (ICA) or MCA stenosis. We monitored intraoperative MCA, STA, and radial artery (RA) pressure. All patients underwent 4D flow MRI preoperatively and 3 wk after surgery to quantify the blood flow volume (BFV) of the ipsilateral ICA (BFViICA), contralateral ICA (BFVcICA), basilar artery (BFVBA), ipsilateral STA (BFViSTA), and contralateral STA (BFVcSTA). The sum of intracranial BFV was defined as BFVtotal. We compared BFV parameters and intraoperative pressure. BFViSTA significantly increased after surgery (P<.001). BFViICA and BFVBA significantly decreased after surgery (BFViICAP=.005; BFVBAP=.02). No significant difference was observed between BFVcICA before and after surgery. As a result, BFVtotal postoperatively increased by 6.8%; however, no significant difference was observed. Flow direction at M1 changed from antegrade to unclear after surgery in 5 patients. Intraoperative MCA pressure and MCA/RA pressure ratio significantly increased after surgery (P<.001). We found a stronger positive correlation between MCA pressure increase ratio and BFVtotal increase ratio in patients with lower pre-MCA pressure (r=0.907, P<.001). The visual and quantitative assessment of 4D flow MRI revealed that intracranial blood flow changes complementarily after STA-MCA bypass surgery. 4D flow MRI may detect the improvement of cerebral perfusion pressure.

Combined standard bypass and parent artery occlusion for management of giant and complex internal carotid artery aneurysms

BackgroundComplex aneurysms do not have a standard protocol for treatment. In this study, we investigate the safety and efficacy of microsurgical revascularization combined with parent artery occlusion (PAO) in giant...

Emergency STA-MCA bypass surgery for symptomatic progressive ischemic stroke

BackgroundIntravascular acute thrombectomy is recommended for acute cerebral infarction within 8 h of onset, based on several randomized controlled trials. However, standard treatment for cases outside these indications has not been established. ObjectiveEmergent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass was performed within 72 h of onset for non-cardiogenic cerebral artery occlusive disease and the surgical outcomes are discussed. MethodsRetrospective review of 18 consecutive patients with non-cardiac cerebrovascular occlusive stroke who underwent emergent bypass surgery from September 2010 to August 2018. Surgical indications were determined as symptomatic ICA or MCA occlusive disease within 8–72 h after onset, and crescendo and/or progressive frequent transient ischemic attack, or impending stroke despite aggressive medical treatment with National Institutes of Health Stroke Scale (NIHSS) at 4 points or more, small cortical infarction (1/3 or less), and observed perfusion-diffusion mismatch. ResultsSurgical outcome was good recovery in 2 patients, moderate disability in 8, severe disability in 6, and death in 2 patients. Favorable outcome was achieved in 55.6%, and poor outcome in 44.4%. No patient showed enlargement of the area of cerebral infarction. The value of the BRS significantly improved after surgery in favourable outcome group. No patient suffered any complication related to surgical intervention including hemorrhagic complications. ConclusionsEmergent STA-MCA bypass surgery can improve clinical outcome and reduce the risk of morbidity under strict surgical indications, so could be an option for acute stage revascularization after ineffective thrombolytic therapy for non-cardiac acute cerebrovascular stroke.

Flow evaluation of STA–MCA bypass using quantitative ultrasonography: An alternative to standard angiography for follow up of bypass graft

PurposeTo date, digital subtraction angiography (DSA) has been considered as the gold imaging modality for assessing graft patency after extracranial–intracranial bypass. The utility of a noninvasive and quantitative method of assessing graft flow postoperatively was evaluated by using quantitative ultrasonography. MethodAll STA-MCA bypass surgery performed over a 5-year period at a single institution were reviewed. Measured by duplex ultrasonography, pre-operative (day1) and post-operative (day1, day7, 3month and 6 month) graft blood flow rates were recorded and analyzed. Results were correlated to Matsushima grade determined by DSA performed within 24 h when ultrasonography was conducted to confirm the graft function. Results100 patients with 131 operated hemispheres were included in this study. The mean flow rates in the STA graft on pre-operative day1, post-operative day 1 and 7, at 3- and 6-month postoperatively were 24.1, 106.7, 112.6, 97.4 and 79.7 ml/min respectively. The mean post-operative flow in the STA graft graded as A/B/C were significantly different (168.0 ± 34.8 ml/min, 91.0 ± 15.5, 42.1 ± 17.2 ml/min, respectively, p = 0.000). 124.5 ml/min and 65.5 ml/min are good cut-off value for predicting post-operative graft Matsushima grade. The analysis also showed excellent agreement between ultrasonography and DSA for assessing bypass function (κ = 0.78). ConclusionsThe patency of the STA grafts can be assessed noninvasively by quantitative ultrasonography, which results are comparable to those of conventional DSA. This, therefore, suggest that quantitative ultrasonography may be an alternative method to standard DSA for serial follow up of STA grafts.

Treatment Strategies of Complex Intracranial aneurysm

Abstract Introduction Treatment of complex aneurysms is amongst the most challenging for neurosurgeons. Complex aneurysms are those aneurysms that could not be normally clipped or treated by conventional endovascular approaches, labeling an aneurysm complex implies increased risk of worse outcome in terms of natural history and/or therapy. Aim of the Work To detect the validity of different lines of management, either surgical or endovascular interventions in treating complex intracranial aneurysms. Methods A prospective cohort study for 80 patients diagnosed with complex intracranial aneurysm lesions that were treated in Ain-Shams and Alexandria University hospitals by surgical or endovascular intervention. Clinical evaluation, radiological diagnosis, treatment options were offered for all patients in details and follow-up after six months were recorded and analyzed. Results The mean age of patients was 39.6 years, with a male to female ratio of 1:0.87 and the commonest age of presentation was (41-60y age group). Amongst 80 patients with 83 aneurysms, 52 (65%) were non-ruptured and 28 (35%) were ruptured. Initial radiological diagnostic tools were CT brain and the commonest finding was SAH in 28 (35%) patients. CT angiogram showed 74 (89%) of the aneurysms in the anterior circulation and 9 (10.8%) in the posterior circulation. Among the 83 aneurysms 56 (67%) were giant and 20 (24.1%) were large in size. ICA aneurysm were 65 and were further sub-classified to Infra-ophthalmic segment (40.9%), Ophthalmic segment (19.2%) and Supra-ophthalmic segment (18.1%). Aneurysms in the vertebro-basilar system 9 aneurysms were further sub-classified to Infra-pica segment (3.61%), PICA segment (1.2%) and Supra-pica segment (6.02%). In this study 22 (26.5%) aneurysms underwent surgical intervention, 12 had ICA ligation PVO, 7 (31.8%) patients clip reconstruction and 3 (13.6%) did STA-MCA bypass surgery. As for Endovascular interventions 61 (76.2%) aneurysms underwent 78 endovascular procedures and five aneurysms did combined endovascular with surgical procedures. All patients were followed by GOS and mRS score over a period of 6 months. Conclusion Patient with ischemic tolerance to BOT, PVO either surgical or by endovascular approach is the first line of management. Surgical clip reconstruction takes the higher hand to endovascular intervention for complex aneurysms with wide neck or those with intracerebral hematoma. Follow-up of all patients post-procedure over a time period is most important for early avoiding any early complications.

Abstract TP129: Intraoperative Prediction of Cerebral Hyperperfusion Syndrome After STA-MCA Bypass Surgery by a Newly Developed Hyperspectral Imaging System

Background: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is the important treatment of moyamoya disease and other cerebral ischemic situations. However, cerebral hyperperfusion syndrome (HPS) may occur after vascular reconstructive surgery including STA-MCA bypass. 123 I-IMP-SPECT is useful to diagnose HPS after surgery, but there is no intraoperative device to predict HPS. Using intraoperative hyperspectral imaging data captured by hyperspectral camera (HSC), we can get the oxygen saturation value (SO2) of brain surface during surgery. We may predict HPS by analyzing intraoperative cerebral cortex SO2. Objective: To investigate whether the data from HSC during surgery is useful for prediction of postoperative HPS. Methods: 10 consecutive patients performed STA-MCA bypass were collected hyperspectral images of cerebral cortex by HSC before and after bypass. We got the SO2 data and analyzed the rate of change and correlation with HPS. Results: 3 patients presented temporary neurological deterioration several days after surgery and 123 I-IMP SPECT revealed focal intense increase in CBF at the sites of anastomosis. In these HPS patients, the rate of change of SO2 of cerebral cortex before and after bypass significantly increased in comparison with the patients didn’t present HPS (1.524 vs 1.089, P=0.0017). The receiver operating characteristic curve reveals if the rate of change of SO2 is more than 1.17, postoperative HPS is likely to occur (sensitivity=83%, AUC=0.81). Conclusions: Using the HSC, we may predict the occurrence of HPS after STA-MCA bypass. HSC can be the useful device in postoperative treatment for prevention of HPS.

Transient neurological deterioration due to watershed shift after STA-MCA bypass surgery in acute atherosclerotic occlusion

Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery is considered not the primary but the last treatment option for acute atherosclerotic occlusions refractory to medical treatment. We retrospectively evaluated patients who underwent STA-MCA bypass surgery for acute atherosclerotic occlusion intractable to other treatments. From June 2010 to May 2014, 10 patients underwent STA-MCA bypass surgery for acute atherosclerotic occlusion at our hospital. The sites of occlusion were the internal carotid artery (n = 5) and the proximal MCA (n = 5). All 10 patients showed good patency in the anastomosis after bypass surgery, and postoperative cerebral angiography showed a newly formed border zone between the existing collateral blood flow and bypass graft blood flow. Transient neurological deterioration (TND) developed in 4 patients after STA-MCA bypass surgery (40%). All 4 patients showed worsened hemiparesis or aphasia 2–3 days after bypass surgery and improvement in neurological deficits within 1 week after bypass surgery. Diffusion MRI in patients with TND showed new cerebral infarctions near the newly formed border zone. In our series of bypass surgeries for acute atherosclerotic occlusion, postoperative changes in hemodynamic status, also called watershed zone shift, may be one of the causes of new cerebral infarctions near the newly formed border zone.