[Venous cerebral complications after microsurgery for complex aneurysms of the middle cerebral arteries]. / Venoznye tserebral'nye oslozhneniya mikrokhirurgicheskikh operatsii po povodu slozhnykh anevrizm srednikh mozgovykh arterii.

Microsurgeries are common for complex aneurysms of the middle cerebral artery (MCA). OBJECTIVE: To evaluate the incidence and types of venous cerebral disorders after microsurgeries for complex MCA aneurysms. MATERIAL AND METHODS: A retrospective study included 285 patients with complex MCA aneurysms between 2009 and 2020. Pterional craniotomy and transsylvian approach were used in all cases. Aneurysm clipping was performed in 230 cases, revascularization - 27, trapping without bypass - 17, reinforcement - in 11 cases. Computed tomography within 1-3 days after surgery recognized venous cerebral disorders as heterogeneous foci of abnormal brain density with unclear boundaries. These foci were crescent-shaped as a rule and located in deep and basal parts of the frontal lobes. RESULTS: Venous abnormalities occurred in 76 (26.7%) patients. Thirty-five (12.3%) patients had mild venous edema of the frontal lobe alone. In 35 (12.3%) patients, we found moderate disorders with focus in the frontal lobe and compression of anterior horn of the left lateral ventricle with or without hemorrhagic imbibition. Severe disorders occurred in 6 (2.1%) patients with lesion extending to the frontal, insular and temporal lobes. These lesions were accompanied by hemorrhagic imbibition, and lateral dislocation exceeded 5 mm. CONCLUSION: Careful dissection of veins in Sylvian fissure with preservation of bridging veins is likely to reduce the risk of this complication. Cauterization of a large vein in Sylvian fissure should be followed by careful hemostasis within frontal or temporal cortex. Bleeding and cortical tension can indicate intracerebral hematoma whose likelihood is higher in patients with venous cerebral disorders.

Transcortical transventricular transchoroidal-fissure approach to distal fusiform hyperplastic anterior choroidal artery aneurysms.

A hyperplastic anterior choroidal artery is a vascular anomaly where the anterior choroidal artery supplies the posterior cerebral artery territory. We report a case of subarachnoid hemorrhage from a hyperplastic anterior choroidal artery with tandem fusiform aneurysms. The patient underwent a temporal craniotomy and transcortical transventricular transchoroidal-fissure approach for clip reconstruction. This case illustrates an unusual cerebrovascular pathology and approach to the ambient cistern.

[Mathematical modeling of high-flow extra-intracranial bypass in the treatment of a complex cerebral aneurysm]. / Matematicheskoe modelirovanie obkhodnogo vysokopotochnogo ekstra-intrakranial'nogo shuntirovaniya pri lechenii slozhnoi tserebral'noi anevrizmy.

BACKGROUND: Intracranial aneurysms (IAs) pose a high risk of spontaneous subarachnoid hemorrhage. In the most complex cases, the only way to exclude the aneurysm from the circulation is to perform a high-flow extracranial-to-intracranial bypass, thus creating a new bloodstream. This avoids severe ischemic complications; however, it requires careful consideration of individual anatomy and hemodynamic parameters. Computational fluid dynamics (CFD) can be of great help in planning such a surgery by creating 3D patient-specific models of cerebral circulation. OBJECTIVE: Assessment of the perspectivity of high-flow extracranial-to-intracranial bypass planning using computational modeling. MATERIAL AND METHODS: In this research work, we have applied the CFD methods to a patient with a giant thrombosed IA of the internal carotid artery (ICA). Preoperative CTA images and Gamma Multivox workstation were used to create a 3D model with current geometry and three additional models: Normal anatomy (no IA), Occlusion (with ligated ICA), Virtual bypass (with bypass and ligated ICA). The postoperative data were also available. Boundary conditions were based on PC-MRI measurements. Calculation of hemodynamics was conducted with a finite element package ANSYS Workbench 19. RESULTS: The results demonstrated an increase in the blood flow on the affected side by more than 70% after the virtual surgery and uniformity of flow distribution between the affected and contralateral sides, indicating that the treatment is likely to be efficient. Later, postoperative data confirmed that. CONCLUSION: The study showed that virtual preoperative CFD modeling could significantly simplify and improve surgical planning.

Effect of obesity on radiation exposure, quality of life scores, and outcomes of fenestrated-branched endovascular aortic repair of pararenal and thoracoabdominal aortic aneurysms.

BACKGROUND: The aim of the present study was to assess the effect of obesity on procedural metrics, radiation exposure, quality of life (QOL), and clinical outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) of pararenal and thoracoabdominal aortic aneurysms. METHODS: We reviewed the clinical data from 334 patients (236 men; mean age, 75 ± 8 years) enrolled in a prospective nonrandomized study to evaluate FB-EVAR from 2013 to 2019. The patients were classified using the body mass index (BMI) as obese (BMI ≥30 kg/m2) or nonobese (BMI <30 kg/m2). QOL questionnaires (short-form 36-item questionnaire) and imaging studies were obtained preoperatively and at 2 months and 6 months postoperatively, and annually thereafter. The procedures were performed using two different fixed imaging systems. The end points included procedural metrics (ie, total operative time, fluoroscopic time, contrast volume), radiation exposure, technical success, 30-day mortality, and major adverse events, QOL changes, freedom from target vessel instability, freedom from reintervention, and patient survival. RESULTS: The aneurysm extent was a pararenal aortic aneurysm in 117 patients (35%) and a thoracoabdominal aortic aneurysm in 217 patients (65%). Both groups had similar demographics, cardiovascular risk factors, and aneurysm extent, except for a greater incidence of hyperlipidemia and diabetes among the obese patients (P < .05). No significant differences were found in the procedural metrics or intraprocedural complications between the groups, except that the obese patients had greater radiation exposure than the nonobese patients (mean, 2.5 vs 1.6 Gy; P < .001), with the highest radiation exposure in those obese patients who had undergone the procedure using system 1 (fusion alone) instead of system 2 (fusion and digital zoom; mean, 4.1 vs 1.5 Gy; P < .001). Three patients had died within 30 days (0.8%), with no difference in mortality or major adverse events between the groups. The mental QOL scores had improved in the obese group at 2 and 12 months compared with the nonobese patients, with persistently higher scores up to 3 years. At 3 years, the obese and nonobese patients had a similar incidence of freedom from target vessel instability (74% ± 6% vs 80% ± 3%; P = .99, log-rank test), freedom from reintervention (66% ± 6% vs 73% ± 4%; P = .77, log-rank test), and patient survival (83% ± 5% vs 75% ± 4%; P = .16, log-rank test). CONCLUSIONS: FB-EVAR was performed with high technical success and low mortality and morbidity, with no significant differences between the obese and nonobese patients. The procedural metrics and outcomes were similar, with the exception of greater radiation exposure among obese patients, especially for the procedures performed using system 1 with fusion alone compared with system 2 (fusion and digital zoom). Obese patients had higher QOL mental scores at 2 and 12 months, with a similar reintervention rate, target vessel outcomes, and survival compared with nonobese patients.

Results of chimney endovascular aneurysm repair as used in the PERICLES Registry to treat patients with suprarenal aortic pathologies.

BACKGROUND: The prevailing evidence calls for using chimney/snorkel endovascular repair (ch-EVAR) with one or two chimney grafts. No studies up to now focus on its applicability and results for the treatment of suprarenal aortic pathologies (SRAP). Hence, we evaluated the clinical and radiologic results of ch-EVAR treatment for SRAP placing three or more chimney grafts within the PERICLES Registry. METHODS: Data from 517 patients suffering complex aortic pathologies treated by ch-EVAR between 2008 and 2014 at 13 European and U.S. centers were retrospectively reviewed and analyzed. RESULTS: Sixty-seven ch-EVAR-treated patients (12.9% of the entire PERICLES cohort) presented SRAP (83.5% elective, 16.5% urgent). The majority of patients (95.5%) received three chimney grafts; four patients received four chimney grafts. The Endurant device was the most commonly used (35.8%) followed by the Zenith abdominal endograft (19.4%). Overall, 204 chimney grafts were placed (56.7% covered self-expandable, 40.3% covered balloon-expandable stents, and 10.4% bare metal balloon-expandable stents). At a median follow-up of 24 months (range, 0.1-67.0 days), 30-day mortality was 6.1% (4 patients), and the overall mortality was 16.4% (11 patients). Overall survival was 87.4% (range, 79.5%-96.0%) at 1 year, 81.8% (range, 72.2%-92.2%) at 2 years and thereafter. Type IA endoleak was noted in nine patients (13.4%) intraoperatively and successfully treated in seven cases (97.1% technical success). Aneurysm sac diameter significantly decreased from 70.5 ± 19.3 mm to 66.9 ± 20.6 mm (P < .001) at last follow-up. Ischemic stroke or transient ischemic attack were noted in two patients (2.9%). Chimney occlusion was detected in six renal arteries (9.5%) and two superior mesenteric arteries (3.2%). No patients required chronic hemodialysis. All occluded superior mesenteric artery grafts were successfully rescued using endovascular approaches. CONCLUSIONS: The midterm use of ch-EVAR for the treatment SRAP seems to be safe, highlighting its applicability for the treatment of rupture threatening pathologies and seal zone lengthening as in type IA endoleaks after EVAR. However, the incidence of type IA endoleaks, chimney graft occlusions, and ischemic stroke rates is higher compared with the prevailing single chimney evidence. Longer follow-up with more cases is needed to establish the exact performance of this treatment in SRAP.

How I do it: superficial temporal artery-middle cerebral artery bypass for flow augmentation and replacement.

BACKGROUND: The superficial temporal artery-middle cerebral artery (STA-MCA) bypass augments blood flow in patients with cerebral ischemia or replaces flow in patients with complex aneurysms or skull base tumors requiring vessel sacrifice. METHOD: We provide a description of the STA-MCA bypass with figures and video to illustrate the procedure. CONCLUSION: The STA-MCA end-to-side anastomosis is a foundational skill for the cerebrovascular surgeon and a building block for more complex bypasses.

[Analysis of local hemodynamics in complex aneurysms: an effect of the vessel arising from the dome or the neck]. / Issledovanie lokal'noi gemodinamiki v slozhnykh anevrizmakh: vliyanie sosuda, otkhodyashchego ot kupola ili sheiki.

BACKGROUND: Assessment of rupture risk for intracranial aneurysms (IA) is a particular challenge in cases of so-called complex aneurysms due to their variable morphometric characteristics. Arterial branch arising from the dome or the neck of IA is one of the least explored features of complex aneurysms. The methods of computational fluid dynamics may be valuable to determine the influence of arterial branches of IA on local hemodynamics. OBJECTIVE: To analyze local hemodynamics in IA with arterial branch arising from the cupola or the neck depending on the structure of the aneurysm and blood flow rate in the parent vessel. MATERIAL AND METHODS: CT angiography data of 4 patients with IA were estimated in this study. Modifications of the baseline 3D models of the aneurysms resulted 12 patient-specific models included into analysis. Hemodynamic calculations were made by using of ANSYS Workbench 19 software package. RESULTS: Wall shear stress (WSS) was characterized by the most significant variability, especially in case of sidewall aneurysms. Small cross-sectional area of additional branch in relation to the neck of IA was not followed by considerable changes of blood flow patterns inside IA after «virtual¼ removal of the vessel. Otherwise, the intensity of flows was drastically reduced. Simulation of high inlet flows demonstrated substantial variation of WSS in the area of jet. CONCLUSION: Additional arterial branch arising from the dome or the neck of IA significantly influences local hemodynamics. This influence depends on the localization of IA in relation to the parent vessel and the diameter of additional arterial branch.

Bypass surgery of complex middle cerebral artery aneurysms-technical aspects and outcomes.

BACKGROUND: The main challenge of bypass surgery of complex MCA aneurysm is not the selection of the bypass type, but the initial decision making of how to exclude the affected vessel segment from circulation. The aim of our study was to review our experience with the treatment of complex MCA aneurysms using revascularization and parent artery sacrifice techniques. Based on this, we aimed at categorizing these aneurysms according to specific surgical aspects in order to facilitate preoperative planning for these challenging surgical pathologies. METHODS: We reviewed 50 patients with complex MCA aneurysms that were not clippable but required revascularization and parent artery sacrifice. We report the individual variations of surgical techniques, highlight the technical aspects, and categorize the aneurysms based on their location and orientation. RESULTS: Of the 50 aneurysms, 56% were giant, 16% large, and 28% < 10 mm, but fusiform. Fourteen percent were previously treated endovascular. Four percent presented with SAH. Ten percent were prebifurcational, 60% involved the bifurcation, and 30% were postbifurcational. Both parent artery sacrifice and bypass strategies were tailored to the individual localization and anatomical relationship of the aneurysm and inflow/outflow arteries (38% proximal inflow occlusion, 42% aneurysm trapping, 20% distal outflow occlusion; 14% STA-MCA bypass, 48% interposition graft, 36%, combined/complex revascularization with reimplantation/in situ techniques). Good outcome (mRS 0-2) rates at discharge and at follow-up were 64% and 84%. Based on our analysis of individual cases, we categorized complex MCA aneurysms into six types and provide individual recommendations for their surgical exploration and treatment by revascularization and parent artery sacrifice. CONCLUSION: Complex MCA aneurysms are among the most challenging vascular lesions and afford highly individualized treatment strategies. Revascularization and parent artery sacrifice provide durable results that are superior to the natural history. Our classification provides a tool for planning and pre-surgical assessment of the intraoperative anatomy of complex MCA aneurysms, helping to assume possible pitfalls.

Giant vertebrobasilar aneurysm: a rare cause of central sleep apnoea.

We report a case of central sleep apnoea (CSA) due to a giant vertebrobasilar aneurysm with brainstem compression. A flow diverter stent was deployed with coil embolization of the right vertebral artery distal to the posterior inferior cerebellar artery (PICA) to occlude the aneurysm. The patient's symptoms improved following therapy.

Introduction of a Team Based Approach to Radiation Dose Reduction in the Enhancement of the Overall Radiation Safety Profile of FEVAR.

OBJECTIVES: Fenestrated endovascular aneurysm repair (FEVAR) exposes operators and patients to considerable amounts of radiation. Introduction of fusion of three-dimensional (3D) computed tomography (CT) with intraoperative fluoroscopy puts new focus on advanced imaging techniques in the operating environment and has been found to reduce radiation and facilitate faster repair. The aim of this study is to evaluate the radiation dose effect of introducing a team-based approach to complex aortic repair. METHODS: Procedural details for a cohort of 21 patients undergoing FEVAR after fusion-guided (Modern Group) imaging was introduced are compared with 21 patients treated in the immediate 12 months prior to implementation (Historic Group) at a centre with expertise in FEVAR. Non-parametric tests were used to compare procedure time (PT), air kerma, dose-area product (DAP), fluoroscopy time (FT), estimated blood loss (EBL) and pre- and post-operative estimated glomerular filtration rate (eGFR) between the groups. RESULTS: Change in operative approach resulted in a significant reduction in PT for the Modern group (median 285 mins; interquartile range 268-322) compared with the Historic group (450 mins; IQR 360-540 p = <0.001). There were reductions in skin dose for the Modern group (1.6 Gy; IQR 1.09-2.1) compared with the Historic group (4.4 Gy; 3.2-7.05 p = <0.001), and DAP (Modern 159 Gy.cm2; IQR 123-226 vs 264.93 Gy.cm2; 173.3-366.8 for Historic (p = 0.006). There were no significant differences in FT, and pre- and post-operative eGFR between the two groups. Weight and height were distributed equally across both groups. Structured dose reports including the changes in frame rate were not available for analysis. CONCLUSIONS: Implementation of a team-based approach to radiation reduction significantly reduces radiation dose. These findings suggest that the radiation safety awareness that accompanies the introduction of fusion imaging may improve the overall radiation safety profile of FEVAR for patients and providers.

Woven Endobridge (WEB) device for endovascular treatment of complex unruptured aneurysms-a single center experience.

INTRODUCTION: The introduction of the Woven Endobridge (WEB) device increases the feasibility of endovascular treatment of wide-neck bifurcation aneurysms with limitations given by currently available sizes and shapes of the device. Parallel to other studies, we used the new device for selected patients who were no optimal candidates for established techniques like neurosurgical clipping or endovascular coiling. We aimed to report the angiographic and clinical results of WEB implantations or combinations between WEB and coiling or intracranial stents. METHODS: We reviewed the records of n = 23 interventions in 22 patients with unruptured wide-neck aneurysms (UIA) who were assigned for aneurysm treatment with the use of the WEB or adjunctive techniques. Interventional procedures and clinical and angiographic outcomes are reported for the periprocedural phase and in mid-term FU. RESULTS: Of the included 22 patients, six patients needed additional coiling, intracranial stenting, or implantation of a flow diverter. WEB implantation was technically feasible in 22 out of the 23 interventions. Follow-up angiographic imaging proved total or subtotal occlusion of the aneurysm in 19 of 22 cases. Two minor recurrences remained stable during a period of 15 months. One patient with a partially thrombosed giant MCA aneurysm had a major recurrence and was retreated with a second WEB in combination with coiling. CONCLUSION: Despite of unfavorable anatomic conditions, broad-based and large UIA endovascular treatment with the WEB and adjunctive techniques was feasible with a low risk of complications and promising occlusion rates in mid-term follow-up.

Distal outflow occlusion with bypass revascularization: last resort measure in managing complex MCA and PICA aneurysms.

BACKGROUND: Partial trapping with or without bypass revascularization is a well-established strategy in the surgical management of complex aneurysms. Distal outflow occlusion is performed by occluding the efferent artery downstream of the aneurysm and represents an alternative to proximal inflow occlusion in partial trapping treatment. With this article we report a case series employing distal outflow occlusion for managing posterior-inferior cerebellar artery (PICA) and middle cerebral artery (MCA) complex aneurysms and discuss the rationale of this treatment strategy. METHODS: A case series of eight patients who underwent surgery for complex PICA (n = 3) and MCA (n = 5) aneurysms by means of distal outflow occlusion and flow-replacement bypass is presented. Two out of the eight patients presented with subarachnoid hemorrhage (SAH) (1 PICA and 1 MCA aneurysm). RESULTS: In seven out of eight patients (87.5 %), total aneurysmal thrombosis was obtained; in one patient, postoperative neuroimaging showed a partial aneurysmal thrombosis. Aneurysm growth or delayed rupture was not observed. All the bypasses were patent at the end of the procedure and all but one at follow-up (asymptomatic occlusion). One patient had postoperative worsening, unrelated to bypass patency. All other patients improved. Three patients maintained an mRS score of 1, four patients had improved mRS scores by ≥1, and 1 patient had a worsened mRS score compared to preoperatively. CONCLUSIONS: We believe that partial trapping with distal outflow occlusion for treating complex intracranial aneurysms represents a useful strategy as a last resort measure. To avoid cerebral ischemia, flow-replacement bypass is key to success.

Stenting complex aorta aneurysms with the Cardiatis multilayer flow modulator: first impressions.

OBJECTIVES: Our aim was to assess the feasibility and efficacy of the Cardiatis multilayer flow modulator in the treatment of complex aorta aneurysms. METHODS: This is a single-center prospective registry. Six patients (4 males and 2 females; mean age 74 years) with complex aorta aneurysms (unsuitable for endovascular repair with standard, fenestrated, or branched stent grafts) were treated with the Cardiatis multilayer flow modulator. RESULTS: Clinical success was 100%. Median follow-up was 10 months. One patient died the third postoperative day due to aneurysm rupture. Four aneurysms were completely thrombosed between 1 and 6 months after the procedure. The patency of the covered aortic branches was 100%. At 6 months, the sac volume was decreased in two patients, increased in two patients and remains stable in one patient. There were no stent migrations, retractions, thrombosis, fractures, or reinterventions. CONCLUSIONS: The device preserves flow into the covered aortic branches and completed aneurysm thrombosis occurs gradually; however, the stent did not prevent rupture immediately after the implantation. Longer follow-up is mandatory to prove the efficacy of this technology.

Navigating Complexity: A Comprehensive Approach to Middle Cerebral Artery Aneurysms.

Background: The concept of aneurysm "complexity" has undergone significant changes in recent years, with advancements in endovascular treatments. However, surgical clipping remains a relevant option for middle cerebral artery (MCA) aneurysms. Hence, the classical criteria used to define surgically complex MCA aneurysms require updating. Our objective is to review our institutional series, considering the impacts of various complexity features, and provide a treatment strategy algorithm. Methods: We conducted a retrospective review of our institutional experience with "complex MCA" aneurysms and analyzed single aneurysmal-related factors influencing treatment decisions. Results: We identified 14 complex cases, each exhibiting at least two complexity criteria, including fusiform shape (57%), large size (35%), giant size (21%), vessel branching from the sac (50%), intrasaccular thrombi (35%), and previous clipping/coiling (14%). In 92% of cases, the aneurysm had a wide neck, and 28% exhibited tortuosity or stenosis of proximal vessels. Conclusions: The optimal management of complex MCA aneurysms depends on a decision-making algorithm that considers various complexity criteria. In a modern medical setting, this process helps clarify the choice of treatment strategy, which should be tailored to factors such as aneurysm morphology and patient characteristics, including a combination of endovascular and surgical techniques.

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.

OBJECTIVE: 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. METHODS: 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). RESULTS: 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 12 months 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 6 months. 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. CONCLUSIONS: 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 12 months, patients with low WPS who underwent partial ICA ligation combined with bypass had postoperative normal BTO.

Giant Middle Cerebral Artery Aneurysms: A 55-Patient Series.

BACKGROUND: The treatment of middle cerebral artery (MCA) giant aneurysms (GAs) represents a challenging task. METHODS: The data for 55 patients treated for MCA GA (≥25 mm) at the N.N. Burdenko NMRCN between 2010 and 2019 were analyZed. RESULTS: The GAs were located in the M1 segment in 11 (20%) patients, MCA bifurcation in 33 (60%), M2 in 7 (12.7%), and M3 in 4 (7.3%). There were 32 (58.2%) saccular and 23 (41.8%) fusiform GAs. MCA GAs were treated with neck clipping (50.9%), clipping with the artery lumen formation (3.6%), bypass surgeries (34.5%), wrapping (3.6%), and endovascular surgery (7.3%). A worsening of the neurologic state in the perioperative period was observed in 50.9% of patients. The complete closure of GA was achieved in 78.2%. Surgery-related mortality was 1.8%. The long-term outcome was favorable in 76.9% of patients. Surgery-related and disease-related plus treatment failures-related mortality was 9.6%. CONCLUSIONS: Microsurgical clipping and bypass surgery are the main operative interventions for MCA GA treatment. These operations are technically complex and are followed by a relatively high percentage of complications. The main tasks that require further investigations are the introduction of new precise diagnostic methods for the collateral circulation assessment in the cortical MCA branches, the perfection of the algorithm for the bypass selection, and investigation of the long-term results of the endovascular and combined treatments. It is of major importance to thoroughly observe the patients long-term after the surgery and ensure the possibility for further angiographic studies.

Anterior Inferior Cerebellar Aneurysm Treated by Aneurysm Resection and Intracranial Artery Anastomosis in situ: A Case Report and Literature Review.

Background: Anterior inferior cerebellar artery (AICA) aneurysms are relatively rare in clinical practice, accounting for <1% of all intracranial arteries. After the diagnosis and location are confirmed by angiography, magnetic resonance, and other imaging examinations, interventional, or surgical treatment is often used, but some complex aneurysms require reconstructive surgery. Case Description: An 8-year-old male child was admitted to the hospital due to sudden disturbance of consciousness for 2 weeks. The head CT showed hematocele in the ventricular system with subarachnoid hemorrhage in the basilar cistern and annular cistern. On admission, he was conscious, answered correctly, had a soft neck, limb muscle strength was normal, and had no cranial nerves or nervous system abnormalities. A preoperative examination showed the right side of the anterior distal arteries class under the circular wide neck aneurysm, the distal anterior inferior cerebellar artery supplying a wide range of blood to the cerebellum, the ipsilateral posterior inferior cerebellar artery absent, and the aneurysm close to the VII, VIII nerves. The aneurysm was successfully treated by aneurysm resection and intracranial artery anastomosis in situ of a2 AICA-a2 AICA. Conclusions: AICA aneurysms are relatively rare; in this case, a complex wide-necked aneurysm was successfully treated by aneurysm resection and anastomosis in situ of a2 AICA-a2 AICA. This case can provide a reference for the surgical treatment of complex anterior cerebellar aneurysms.

Surgical Management of Giant Intracranial Aneurysms: Overall Results of a Large Series.

OBJECTIVE: To review and discuss surgical treatment options for giant intracranial aneurysms (GIAs), focusing on indications, technical aspects, and results, along with some illustrative cases. METHODS: We reviewed the data of 82 consecutive patients surgically managed between January 2000 and December 2019 for treatment of a GIA. RESULTS: Male sex and hemorrhage at presentation were prevalent. The average follow-up was 81.2 ± 45 months. The anterior circulation was involved in 76.8% of GIAs. If the GIA showed a clear neck, minimal atherosclerosis, or intrasaccular thrombosis, and ≤2 branches arising from the neck, it was reconstructed. This procedure was possible in 78% of cases. The technique also involved temporary clipping, remodeling, and thrombectomy, as well as fragmentation techniques. Angioarchitectural features other than these techniques underwent bypass and aneurysm trapping. Most bypasses were extracranial to intracranial and high flow. Flow capacity, collateral circulation, and availability of the donor vessel mainly affected the choice of the type of bypass. Overall, successful exclusion of the GIA was 91.4%. The need for retreatment and complication rate were 3.6% and 19.5%, respectively. A good overall outcome (modified Rankin Scale score 0-3) was achieved in 84.2% of patients, and mortality was 10%. CONCLUSIONS: Microneurosurgical techniques still maintain a significant role for most GIAs, with a high durability and acceptable rate of morbidity and mortality. Clip reconstruction is the first-line surgical treatment option, whereas bypass is indicated in cases of planned or unplanned sacrifice of the parent artery to prevent long-term ischemic complications.

Microneurosurgical management of giant intracranial aneurysms: Datasets of a twenty-year experience.

The data presented in this brief paper aims to summarize the overall results of 82 consecutive patients surgically treated over 20 years for a giant intracranial aneurysm (GIA) in the context of the endovascular era. Data were retrospectively collected from the database of two different tertiary referral Italian hospitals. A retrospective analysis of the patients' cohort was performed. Data are presented as they relate to the demographic and clinical aspects, the prevalence of GIAs according to anterior and posterior circulation, aneurysm angioarchitectural features, surgical treatment options, complications, outcome, and main microneurosurgical techniques required explicitly for GIAs, namely temporary clipping, aneurysm remodeling, thrombectomy, fragmentation, and bypass. Furthermore, data about the effects of implementing the flow-diverter/flow-disruptor on the surgical case volume over the years are also reported. The data presented herein are related to our previously published research article titled "Surgical Management of Giant Intracranial Aneurysms: Overall Results of a Large Series" (2020) [1].

Tailored Communicating Bypass for the Management of Complex Anterior Communicating Artery Aneurysms: "Flow-Counteraction" In Situ Bypass and Interposition Bypass Using Contralateral A2 Orifice as Donor Site.

BACKGROUND: The use of bypass surgery for anterior communicating artery (ACOM) aneurysms is technically challenging. Communicating bypass (COMB), such as pericallosal artery side-to-side anastomosis, is the most frequently used and anatomically directed reconstruction option. However, in many complex cases, this technique may not afford a sufficient blood supply or necessitate sacrificing the ACOM and the eloquent perforators arising from it. OBJECTIVE: To evaluate tailored COMB and propose a practical algorithm for the management of complex ACOM aneurysms. METHODS: For 1 patient with an aneurysm incorporating the entire ACOM, conventional in Situ A3-A3 bypass was performed as the sole treatment in order to create competing flow for aneurysm obliteration, sparing the sacrifice of eloquent perforators. In situations in which A2s were asymmetric in the other case, the contralateral A2 orifice was selected as the donor site to provide adequate blood flow by employing a short segment of the interposition graft. RESULTS: The aneurysm was not visualized in patients with in Situ A3-A3 bypass because of the "flow-counteraction" strategy. The second patient, who underwent implementation of the contralateral A2 orifice for ipsilateral A3 interposition bypass, demonstrated sufficient bypass patency and complete obliteration of the aneurysm. CONCLUSION: The feasibility of conventional COMB combined with complete trapping may only be constrained to selected ideal cases for the treatment of complex ACOM aneurysms. Innovative modifications should be designed in order to create individualized strategies for each patient because of the complexity of hemodynamics and the vascular architecture. Flow-counteraction in Situ bypass and interposition bypass using the contralateral A2 orifice as the donor site are 2 novel modalities for optimizing the advantages and broadening the applications of COMB for the treatment of complex ACOM aneurysms.