Middle Cerebral Artery Bypass Research Articles

Vessel wall imaging in the diagnosis of antiphospholipid syndrome presenting as Moyamoya syndrome-A case report.

Objectives: We describe a case of anti-phospholipid syndrome (APLS) vasculopathy presenting with Moyamoya syndrome (MMS) and show the associated intracranial vessel wall MRI (VWI) findings. Methods: A 37-year-old-woman presented with acute onset dizziness and left-sided weakness. Neurologic exam revealed a left facial droop and left hemiparesis. She underwent a comprehensive laboratory work-up for stroke. Neuroimaging included a CT head, CT angiogram, VWI, and digital subtraction angiography. Results: Work-up revealed a triple-positive APLS antibody profile. CT of the head showed an acute right basal ganglia infarction and right frontal subarachnoid hemorrhage. CT angiogram revealed severe stenosis of the right internal carotid artery terminus in a Moyamoya pattern. Intracranial VWI showed long-segment concentric vessel wall thickening and homogeneous vessel wall enhancement and T2-hyperintense wall edema of the stenotic right ICA terminus, M1 middle cerebral artery, and A1 anterior cerebral artery. She was treated with long-term anticoagulation with warfarin and a right superficial temporal artery to middle cerebral artery bypass. Discussion: We present intracranial VWI features of vessel wall pathology in a patient with primary APLS presenting with MMS.

One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms

BackgroundAneurysms located in the distal middle cerebral artery (MCA) are relatively rare and lack an established treatment strategy. For distal MCA (DMCA) aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. MethodsCases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients’ and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. ResultsSix patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all six cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in one case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass were confirmed in all cases. ConclusionsThe one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Waveform Analysis of STA-MCA Bypass graft in Revascularization Surgery for Moyamoya Disease.

Postoperative hyperperfusion syndrome (PHS) is a well-known complication following superficial temporal artery (STA)-middle cerebral artery (MCA) bypass for moyamoya disease (MMD). The early detection of postoperative radiological hyperperfusion (PRH), characterized by a transient increase in local cerebral blood flow (CBF), is crucial for the early diagnosis of PHS. This study aimed to investigate the effectiveness of waveform analysis for early PRH detection. We reviewed 52 consecutive patients who underwent STA-MCA bypass for MMD. Patients were divided into PRH and non-PRH groups based on the postoperative/preoperative CBF ratio. We collected the intraoperative bypass graft waveform and bypass flow data using a flowmeter. The pulsatile index (PI), an indicator of peripheral vascular resistance (PVR), was calculated from bypass flow data. Next, the newly proposed index of PVR, the ratio of the time from peak to 50% decay and to 100% decay (RT50), was calculated through waveform analysis. The values were then compared between the PRH and non-PRH groups. Twenty-seven of the 52 patients met the inclusion criteria. Fourteen of these 27 patients showed PRH. The RT50, but not the PI, was significantly higher in the PRH group. Linear regression analysis revealed a significant correlation between the RT50 and PI. In the receiver operating characteristic for predicting PRH, the area under the curve of RT50 was 0.750, with a cutoff value of 0.255, a sensitivity of 0.928, and a specificity of 0.500. The RT50 obtained from waveform analysis is associated with PVR and can be useful for the early detection of PRH in patients with MMD.

Fluorescein videoangiography (FL-VAG) as a predictor of cerebral bypass patency

BackgroundThe fluorescein videoangiography (FL-VAG) has become a valuable adjunct tool in vascular neurosurgery. This work describes using the FL-VAG during bypass surgery and proposes a classification method for evaluating surgical results. MethodsWe analyzed 26 patients with 50 cerebral bypasses from September 2018 to September 2022. We used a three grades classification method based on the pass of intravenous fluorescein through the anastomosis. Grade 1 represents the synchronous and total filling of the "T" shape ("green T″) formed by the donor and recipient vessel, Grade 2, the asynchronous filling of the anastomosis (incomplete/asynchronous "green T″), and Grade 3, a non-patent anastomosis (absence of "green T″). ResultsOf the 26 patients, 8 underwent one bypass, 14 underwent double bypass, 2 underwent three bypasses, and 2 underwent four bypasses in two different interventions. The type of bypass was end-to-side anastomosis in 47 (94%) cases, internal maxillary artery to middle cerebral artery bypass with a radial artery graft (IMax-MCA anastomosis) in 2 (4%), and PICA-VA transposition in one (2%). We made 24 (48%) bypasses on the right side and 26 (52%) on the left side. After the initial surgery, thirty-nine (78%) bypasses were considered as Grade 1, 5 (10%) as Grade 2, and 6 (12%) as Grade 3. After intraoperative bypass patency assessment (IBPA), 45 (90%) of the bypasses were considered Grade 1 and remained patent on CTA. ConclusionsUsing FL-VAG and a three-tier classification method is a reliable tool to predict bypass patency. It is safe, low-risk, and available worldwide.

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.

Reversal of Cerebral Arteriopathy Post-Hematopoietic Stem Cell Transplant for Sickle Cell Disease.

Sickle cell disease (SCD) is a chronic hematologic disorder which causes progressive cerebral arteriopathy beginning in childhood. As a result, arterial ischemic stroke is a major cause of morbidity and mortality in SCD, and SCD is a leading cause of childhood stroke worldwide. Allogenic hematopoietic stem cell transplant (HSCT) may be curative for individuals with SCD. Long-term outcomes and effects are currently being studied. In this report, we describe a child with SCD who presented with arterial ischemic stroke at 6 years of age and was found to have a severe form of cerebral large vessel arteriopathy by catheter-directed angiography. The patient initially underwent revascularization surgery by indirect superficial temporal artery to middle cerebral artery bypass, and 1 year later, he underwent curative HSCT. Approximately 3 years after HSCT, repeat catheter-directed angiography revealed a striking reversal of cerebral large vessel arteriopathy. This article reveals a previously unrecognized and potentially beneficial effect of HSCT that may ameliorate cerebral large vessel arteriopathy and improve cerebrovascular health for children with SCD.

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.

Internal maxillary artery (IMax) - middle cerebral artery bypass in a patient with bilateral atherosclerotic carotid occlusion: A technical case report.

Since the first description of the possible utilization of the internal maxillary artery for bypass surgery, there are some reports of its use in aneurysm cases; however, there is no information about the possible advantages of this type of bypass for cerebral ischemic disease. We present a 77-year-old man with a history of diabetes, hypertension, systemic atherosclerosis, and two acute myocardial infarctions with left hemiparesis. Imaging studies reported total occlusion of the right internal carotid artery and 75% occlusion on the left side, with an old opercular infarction and repeated transient ischemic attacks in the right middle cerebral artery territory despite medical treatment. After a consensus, we decided to perform a bypass from the internal maxillary artery to the M2 segment of the middle cerebral artery using a radial artery graft. After performing the proximal anastomosis, the calculated graft's free flow was 216 ml/min. Subsequently, after completing the bypass, the patency was confirmed with fluorescein videoangiography and intraoperative Doppler. Postoperatively, imaging studies showed improvement in the perfusion values and the hemiparesis from 3/5 to 4+/5. The patient was discharged one week after the operation, with a modified Rankin scale of 1, without added deficits. The use of revascularization techniques in steno-occlusive disease indicates a select group of patients that may benefit from this procedure. In addition, internal maxillary artery bypass has provided a safe option for large areas of ischemia that cannot be supplied with a superficial temporal artery - middle cerebral artery bypass.

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.

Abstract 042: Cognitive outcomes in patients with carotid insufficiency after undergoing direct extracranial‐intracranial bypass

Introduction Extracranial‐intracranial (EC‐IC) bypass is a niche procedure that has been selectively used for flow augmentation or flow restoration in patients with intracranial carotid insufficiency.1 The underlying etiology varies but is most commonly related to Moya Moya disease (MMD) or intracranial carotid atherosclerotic disease (ICAD).2 Patients are often managed non‐operatively until they begin to develop symptoms such as transient ischemic attacks (TIAs) or strokes that are recalcitrant to maximal medical management, at which point bypass is pursued.1 This lag period, however, could put patients at risk for long term deficit, not only in the form of focal neurological deficits but also in terms of overall neurocognitive capability.3 Several reports have previously demonstrated some level of association between EC‐IC bypass and neurocognitive outcomes, though in isolated populations of either MMD or ICAD.4,5 We therefore aim to further assess the relationship between EC‐IC bypass and neurocognitive outcomes in patients with intracranial carotid insufficiency. Methods Patients ages 18 years and up undergoing EC‐IC bypass were identified from a single institution database between January 2020 and December 2021. Patient records were reviewed for demographic data including age and sex, as well as preoperative clinical information including comorbidities, operative indication, anticoagulation/antiplatelet therapy usage, prior ischemic stroke, modified Rankin score (mRS), and Montreal Cognitive Assessment (MOCA) score. Radiographic data was also collected including Suzuki grade, collateralization, and perfusion. Post‐operative clinical information including complications, discharge mRS, and discharge MOCA scores were identified. Follow‐up duration, MOCA scores, and mRS were also identified and recorded. Results Of the forty‐four patients that underwent EC‐IC bypass during the specified period, ten had cognitive assessments before and after surgery available for review. The indications for bypass in these cases were ICA steno‐occlusive disease resulting in strokes despite maximal medical management in 9 cases, and MMD in one case. Suzuki grade was IV in the MMD case. Pial collaterals were present in 7 cases, and ECA collaterals were present in 5. Prior ischemic strokes were present in 8 cases, with a preoperative mRS range from 1‐4 (median 1), and average MOCA of 20. Perfusion imaging demonstrated a Tmax mismatch in eight cases, with an average volume of 73.6 cc at risk. All patients underwent direct superficial temporal artery to middle cerebral artery bypass, with additional encephaloduroarteriomyosynangiosis (EDAMS). Follow up MOCA score was improved in 8 cases, unchanged in one case, and worsened in one case (average MOCA increased from 20 to 23). Follow up mRS ranged from 0‐2. Additionally, CT perfusion demonstrated notable improvements in Tmax &gt;4 seconds (decrease from 176 cc to 110 cc), Tmax &gt;6 seconds (decrease from 59 cc to 29 cc), and mismatch (decrease from 59 cc to 17 cc) at 6 month follow up. Conclusion Patients with carotid insufficiency from MMD or ICAD undergoing EC‐IC bypass demonstrate well below normal preoperative MOCA scores. This is suggestive of ongoing neurocognitive decline, which is an often overlooked issue in patients with these pathologies. MOCA and mRS both appear to improve in patients after bypass at longer term follow‐up, suggesting that bypass may be an effective method of addressing the issue of neurocognitive decline in patients with carotid insufficiency.

Salvage Maneuvers for Occluded Bypass in Cerebral Revascularization Procedures

ObjectCerebral revascularization is an effective measure for dealing with complicated intracranial aneurysms and ischemic cerebro-vascular disease. Intra-operative thrombosis causing bypass occlusion is a severe issue that cause devastating consequences for complication in revascularization. We report our experiences regarding salvage maneuvers for intraoperative thrombosis in cerebral revascularization procedures and discuss the characteristics and culprits. MethodsWe investigated 720 consecutive patients who underwent cerebral revascularization at the First Affiliated Hospital of Soochow University from January 2013 to October 2021, including 688 patients who underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and 32 patients who underwent extracranial artery-radial artery (ECA-RA)-MCA bypass. Forty-one patients experienced intracranial aneurysms, and the remaining 679 patients was involved in moyamoya disease (MMD), skull base tumors, intracranial occlusive vascular diseases, or other cerebrovascular diseases. All clinical characteristics, clinical imaging examinations and neurological outcomes were studied pre- and postoperatively. The patency of bypasses was confirmed by intraoperative doppler ultrasonography and indocyanine green (ICG) videoangiography. ResultsSeven intraoperative thromboses, which were confirmed by intraoperative doppler ultrasonography and ICG videoangiography, including STA-MCA bypass (n=5) and ECA-RA-MCA bypass (n=2), were observed in 720 patients who underwent cerebral revascularization. The anastomotic stoma remained patent in 6 of 7 patients with intraoperative thrombosis after treatment. One case in STA-MCA bypass failed to be salvaged. Of the four intraoperative thrombosis in STA-MCA bypass for MMD being successfully saved, two were salvaged by applying gelfoam around the site of the anastomosis to relieve the downward compression effect of the donor vessel(STA) on the recipient vessel(M4 segment of MCA).One case in ECA-RA-MCA bypass were salvaged by thrombectomy through donor arteriotomy (radial artery) and reanastomosis. The other case was salvaged by complete reanastomosis. All seven patients who experienced intraoperative thrombosis achieved favorable outcomes at discharge and the 6-month follow-up. ConclusionVarious factors are responsible for intraoperative thrombosis in cerebral revascularization. Relieving the downward compression effect of the donor vessel STA on the recipient vessel M4 segment of MCA by applying gelfoam around the site of the anastomosis stoma, can be recommend to salvage the intraoperative thrombosis in cerebral revascularization.

Novel Method of Calculation of Magnetic Resonance Imaging Perfusion and Comparison of Single versus Double Barrel Superficial Temporal Artery-Middle Cerebral Artery Bypass for Revascularisation in Moya Moya Disease

IntroductionMoyamoya disease (MMD) is characterised by supraclinoid internal carotid artery (ICA) narrowing causing cerebral parenchyma to starve. Direct and indirect revascularisation techniques are the treatment norm. We provide a clinicoradiological comparison of single and double barrel superficial temporal artery to middle cerebral artery (STA-MCA) bypass for MMD. The perfusion in cerebral hemispheres and vessel density in DSA have been evaluated using novel algorithms. MethodsDSA, ASL MR imaging methods and Suzuki, Matsushima, Angiographic Outcome Score (AOS) scales were used to quantify perfusion parameters; modified Rankin score (mRS) was used for clinical evaluation. A novel image processing algorithm was designed to perform analysis of ASL sequences and compare perfusion. Vessel density was calculated using connected component analysis on thresholded DSA images. Results54 hemispheres with MMD underwent STA-MCA bypass 42(77.8%) single barrel and 12 (22.2%) double barrel. Clinical outcome - mRS was significant with p<0.001 in single barrel and p=0.001 in double barrel groups. The overall AOS showed improvement post-operatively (p=0.032).Perfusion analysis was performed in 20 hemispheres (13 single barrel; 7 double barrel). MCA territories showed significant improvement in single barrel (2.72%, p=0.0294) and double barrel groups (12.89%, p=0.025). Vessel density calculated in MCA territory, showed an overall post-op improvement (p=1.75 x 10-8). ConclusionDouble barrel STA-MCA bypass clinically as well as radiologically improves perfusion in the ACA as well as MCA territories in MMD. The novel image processing algorithm is an accurate, objective tool to evaluate perfusion in MR images and vessel density in DSA images of MMD.

Hybrid Treatment for a Giant Fusiform Partially Thrombosed Middle Cerebral Artery Aneurysm With Superficial Temporal Artery to Middle Cerebral Artery Bypass Followed by Endovascular Vessel Sacrifice: 2-Dimensional Operative Video.

Hybrid Treatment for a Giant Fusiform Partially Thrombosed Middle Cerebral Artery Aneurysm With Superficial Temporal Artery to Middle Cerebral Artery Bypass Followed by Endovascular Vessel Sacrifice: 2-Dimensional Operative Video.

Proximal Internal Carotid Artery Occlusion and Extracranial-Intracranial Bypass for Treatment of Fusiform and Giant Internal Carotid Artery Aneurysms

To discuss the treatment of intracranial fusiform and giant internal carotid artery (ICA) aneurysms via revascularization based on our institutional experience. An institutional review board-approved retrospective analysis was performed of patients with unruptured fusiform and giant intracranial ICA aneurysms treated from November 1991 to May 2020. All patients were evaluated for extracranial-intracranial (EC-IC) bypass and ICA occlusion. Thirty-eight patients were identified. Initially, patients failing preoperative balloon test occlusion were treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and concurrent proximal ICA ligation. We then treated them with STA-MCA bypass, followed by staged balloon test occlusion, and, if they passed, endovascular ICA coil occlusion. We treat all surgical medically uncomplicated patients with double-barrel STA-MCA bypass and concurrent proximal ICA ligation. The mean length of follow-up was 99 months. Symptom stability or improvement was noted in 85% of patients. Bypass graft patency was 92.1%, and all surviving patients had patent bypasses at their last angiogram. Aneurysm occlusion was complete in 90.9% of patients completing proximal ICA ligation. Three patients experienced ischemic complications and 4 patients experienced hemorrhagic complications. Not all fusiform intracranial ICA aneurysms require intervention, except when life-threatening rupture risk is high or symptomatic management is necessary to preserve function and quality of life. EC-IC bypass can augment the safety of proximal ICA occlusion. The rate of complete aneurysm occlusion with this treatment is 90.9%, and long-term bypass graft-related complications are rare. Perioperative stroke is a major risk, and continued evolution of treatment is required.

Double-barrel STA-MCA bypass for a giant thrombosed supraclinoid ICA aneurysm with gangliocapsular infarct – A case report

Extracranial-intracranial (EC-IC) bypass is an essential tool for cerebral revascularization procedure. Superficial temporal artery–middle cerebral artery (STA-MCA) bypass was usually performed using one stem of the STA only. In an attempt to augment the flow and to direct the flow to different ischemic areas of the brain, a “double-barrel” technique is used, in which both branches of the STA are used to revascularize distinct MCA territories. Though there are many advancements in endovascular procedures, still STA MCA bypass plays a role in selected cases. We report a 50 years old female with giant thrombosed supraclinoid segment internal carotid artery (ICA) aneurysm with gangliocapsular infarct presented with vision loss, and limb weakness. Patient underwent double barrel STA-MCA bypass, post operatively patient improved of symptoms and patient was discharged in a stable condition. Though endovascular techniques have evolved exponentially over the last few years, and most of these complex aneurysms can be treated using flow-diverting techniques.Though the need for microsurgical intervention is diminished iin this endovascular era, still the surgeons should think about these revascularization procedures as it gives life-long durable solution.

The M2-M1 middle cerebral artery reimplantation bypass with protective superficial temporal artery to middle cerebral artery bypass for giant partially thrombosed middle cerebral artery aneurysm in the hybrid operating suite.

Giant middle cerebral artery (MCA) aneurysms are complex and challenging. Revascularization is frequently required in addition to trapping or clip reconstruction, and the MCA reimplantation bypass is ultimately needed when aneurysm excision is planned. The operation was conducted in the hybrid operating suite, where an intraoperative cerebral angiography revealed a compromised MCA after multiple attempts of clip reconstruction. Therefore, we decided to perform an M2-M1 reimplantation bypass in conjunction with trapping and aneurysmectomy. Reimplantation bypass can be a rescue procedure for revascularization in complex aneurysms. The angioarchitecture varies among individuals; therefore, the optimal bypass technique should be tailored.

Disappearance of a moyamoya-related distal anterior cerebral artery aneurysm after target bypass revascularization: illustrative case.

Aneurysm formation is a complication of moyamoya disease (MMD). Distal anterior cerebral artery (ACA) aneurysms account for approximately 1% of MMD-related aneurysms. We report a case of target bypass for adult patients with MMD who presented with intracranial hemorrhage due to rupture of a distal ACA aneurysm, whose disappearance was confirmed postoperatively. A 45-year-old woman presented with sudden-onset headache and loss of consciousness. Head computed tomography showed hemorrhage in the genu of the corpus callosum with intraventricular extension. Digital subtraction angiography (DSA) revealed Suzuki stage III MMD and a left A3 segment aneurysm. Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and STA-ACA target bypass were performed to reduce hemodynamic stress on the left ACA. DSA 6 months after surgery showed patency of both bypasses and disappearance of the aneurysm. At the 20-month follow-up, the patient was asymptomatic and neurologically intact. Bypass revascularization may be an effective treatment to reduce hemodynamic stress and eliminate MMD-related aneurysms.

Study of Microsurgical Anatomy of Middle Cerebral Artery in Human Cadaveric Brain

ABSTRACT Background: Micro-dissection of cadaver specimens is the base, on which our knowledge of the intricate anatomy of the human brain. Microsurgical anatomy of middle cerebral artery (MCA) is of particulate interest to neurosurgeons as it is the largest and most complex arterial system of the brain. Although various studies have been done on MCA, no such study has been done taking into consideration large sample size of the Indian population. This study will be advantageous in improving knowledge of MCA and its variations. This will prove useful for neurosurgeons in performing microsurgeries. Objective: A study of the microsurgical anatomy of the MCA in human cadaveric brain; comparison of the findings with the existing studies and implication of these finding in micro-neurosurgical procedures. Materials and Methods: Sixteen formalin-fixed cadaveric brains, that is, 32 vessels from its origin from the internal cerebral artery to M1 segment with respect to diameter, length and branching pattern were studied under high magnification (operating microscope) and the data compared with literature. Results: The mean length of M1 was 24.1 ± 11 mm with the outer diameter of 3.1 ± 08 mm. An average number of perforators pre-bifurcation was 7 and post-bifurcation was 3. The pattern of branching of the main trunk was bifurcation (70%), trifurcation (20%) and tetrafurcation (10%), and amongst this, inferior trunk dominance was seen in 70%. An average number of early cortical branch was 3. Conclusion: The knowledge of anatomy of MCA and its variations is important for neurosurgical residents’ training and neurosurgeons dealing with MCA aneurysm management or bypass surgeries.

Hyperperfusion syndrome after superficial temporal artery-middle cerebral artery bypass for non-moyamoya steno-occlusive disease

Background and ObjectivesStroke is a major cause of morbidity and mortality worldwide, and intracranial stenoses increase the risk for stroke. Superficial temporal artery to middle cerebral artery bypass can be beneficial in selected patients with non-moyamoya steno-occlusive disease, however data is limited regarding the postoperative occurrence of hyperperfusion syndrome in this population. This case series describes the outcomes and complications, including hyperperfusion, in these patients who underwent bypass. MethodsThis is a retrospective review of bypass procedures done for medically refractory intracranial stenosis at a single institution by a single surgeon between 2014 and 2021. Results30 patients underwent 33 bypass procedures for unequivocal non-moyamoya steno-occlusive disease. All patients had immediate bypass patency on post-operative day one. Major perioperative complications (9%) included one stroke and two cases of hyperperfusion syndrome. Minor perioperative complications (12%) included two seizures, one superficial wound infection and one deep vein thrombosis. Modified Rankin Score improved in 20 patients (74%), worsened in one patient (4%), and remained stable in seven patients (22%) at the last follow up. Twenty-three patients (85%) had scores ≤ 2. The recurrent stroke rate was 3% at 30 days and 7% at two years. The bypass patency rate at one year was 87.5%. ConclusionIn this series, bypass for patients with medically refractory non-moyamoya steno-occlusive disease was well tolerated and effective, with overall favorable outcomes. The occurrence of hyperperfusion syndrome is rare but significant and should be considered in post-operative management of this population.

Revisiting flow augmentation bypass for cerebrovascular atherosclerotic vaso-occlusive disease: Single-surgeon series and review of the literature.

Despite advances in the nonsurgical management of cerebrovascular atherosclerotic steno-occlusive disease, approximately 15-20% of patients remain at high risk for recurrent ischemia. The benefit of revascularization with flow augmentation bypass has been demonstrated in studies of Moyamoya vasculopathy. Unfortunately, there are mixed results for the use of flow augmentation in atherosclerotic cerebrovascular disease. We conducted a study to examine the efficacy and long term outcomes of superficial temporal artery to middle cerebral artery (STA-MCA) bypass in patients with recurrent ischemia despite optimal medical management. A single-institution retrospective review of patients receiving flow augmentation bypass from 2013-2021 was conducted. Patients with non-Moyamoya vaso-occlusive disease (VOD) who had continued ischemic symptoms or strokes despite best medical management were included. The primary outcome was time to post-operative stroke. Time from cerebrovascular accident to surgery, complications, imaging results, and modified Rankin Scale (mRS) scores were aggregated. Twenty patients met inclusion criteria. The median time from cerebrovascular accident to surgery was 87 (28-105.0) days. Only one patient (5%) had a stroke at 66 days post-op. One (5%) patient had a post-operative scalp infection, while 3 (15%) developed post-operative seizures. All 20 (100%) bypasses remained patent at follow-up. The median mRS score at follow up was significantly improved from presentation from 2.5 (1-3) to 1 (0-2), P = .013. For patients with high-risk non-Moyamoya VOD who have failed optimal medical therapy, contemporary approaches to flow augmentation with STA-MCA bypass may prevent future ischemic events with a low complication rate.