High-flow Bypass Research Articles

Extracranial-intracranial bypass using a cephalic vein graft for iatrogenic internal carotid artery injury during functional endoscopic sinus surgery: illustrative case.

Injury to the internal carotid artery (ICA) during functional endoscopic sinus surgery is a rare but potentially fatal complication. Although treatment algorithms have been developed, guidelines for effectively managing iatrogenic ICA injury have not been established. A case of ICA perforation during functional endoscopic sinus surgery treated with cerebral bypass utilizing a cephalic vein graft is presented. A woman in her late 50s presented with a left cavernous ICA injury that had occurred during endoscopic nasal polypectomy at an outside hospital. Hemostasis was achieved with intranasal Foley catheter placement. Left common carotid artery angiography revealed a high-flow carotid-cavernous fistula. Cerebral revascularization was chosen as the optimal procedure. The initial intent was to use a radial artery graft, but the radial artery was found to be occluded intraoperatively. Postoperatively, the patient experienced decreased vision and left eye movement but was otherwise neurologically intact. Postoperative angiography showed complete resolution of the fistula. In cases involving ICA injury and carotid-cavernous fistula formation, microsurgical trapping with high-flow bypass is a favorable treatment option. The cephalic vein is a viable graft option when unexpected challenges arise with a radial artery graft. https://thejns.org/doi/10.3171/CASE24222.

Treatment strategy of carotid blowout syndrome after radiotherapy for nasopharyngeal carcinoma

Objective:To investigate the treatment of internal carotid artery rupture after radiotherapy for nasopharyngeal carcinoma. Methods:The clinical data of 7 patients with internal carotid artery rupture after radiotherapy for nasopharyngeal carcinoma from March 2020 to March 2023 were retrospectively analyzed. Results:Skull base osteonecrosis with infection occurred in 4 cases, and tumor recurrence with infection in 3 cases. DSA showed that internal carotid artery rupture was located in the internal carotid artery petrosal segment in 6 cases, and in the paravicular segment in 1 case. Balloon occlusion test（BOT） was performed in 6 patients, of which 3 passed and 3 failed. Vascular treatment included internal carotid artery embolization（4 cases）, false aneurysm embolization 1 case（rebleeding）, coated stent 1 case（rebleeding）, muscle compression during operation（1 case）. Patients with rebleeding received high-flow bypass. Three cases developed cerebral infarction after embolization without severe sequelae after treatment, and no death occurred within 90 days. After bleeding control, all 3 patients with cranial base necrosis received surgical treatment to remove the necrotic bone and tissue flap repair, and 1 patient with recurrence received gamma knife and targeted therapy, 1 patient received immune and surgical therapy, and 1 patient received immune and targeted therapy. Conclusion:Rupture and hemorrhage of internal carotid artery after radiotherapy is related to tumor invasion, tissue injury and local infection after radiotherapy. For those caused by tumor invasion, it is recommended to sacrifice the responsible vessels. For those caused by infection, emergency surgery is recommended and blood vessels preserved. Emergency vascular occlusion remains a life-saving option.

Flow Diversion Effect in a Saphenous Vein Graft Aneurysm Using a Double-Layer Micromesh Stent: A Case Report.

A double-layer micromesh stent is designed for the treatment of carotid artery stenosis that has been reported to potentially provide a flow diversion effect. However, the actual flow diversion effect of stents remains unclear. Here, we present a case of a growing saphenous vein graft (SVG) aneurysm treated with the placement of the double-layer micromesh stent using its flow diversion effect. A 66-year-old woman, who underwent high-flow bypass using a SVG for a blister-like internal carotid artery aneurysm 13 years earlier at our institute, was referred to our hospital with a pulsatile cervical mass. Magnetic resonance angiography showed a 9-mm aneurysm on the left SVG, although the aneurysm was a small pouch 4 years earlier. Digital subtracted angiography demonstrated a 9.4 × 8.3-mm aneurysm from the SVG at the auricular level. Because the diameter of the graft was larger than that of the available flow diverter stents in Japan, we decided to place the double-layer micromesh stent (CASPER RX, 7 × 25 mm MicroVention) using its flow diversion effect. Computational fluid dynamics analysis before and after stent deployment showed a significant reduction in the average flow velocity and wall shear stress in the aneurysm, indicating actual flow diversion. An angiogram 2 months postoperatively showed complete obliteration of the aneurysm. Obliteration of the saphenous vein aneurysm was achieved because of the flow diversion effect of the double-layer micromesh stent. The stents might be a feasible alternative for treating cervical carotid aneurysms.

Pseudoaneurysm of the Petrous Section Internal Carotid: A Co-incidence or a Complication of Chronic Otitis Media: A Case Report

Although rare, a Petrous Internal Carotid Artery (ICA) pseudoaneurysm is a possible complication following chronic otitis media. A 57-year-old woman was brought to the Emergency Department with multiple painless episodes of right ear bleeding and epistaxis over the last two months. Upon evaluation, bony dehiscence was observed over the petrous carotid’s first (proximal) genu, along with a pseudoaneurysm detected in the Magnetic Resonance Angiography (MR angiogram). The Balloon Occlusion Test (BTO) showed no cross-flow from the opposite side. Consequently, the patient was considered for high-flow bypass surgery between the external carotid artery and the M2 segment of the Middle Cerebral Artery (MCA), utilising a radial artery graft in the neurosurgery specialty. The present rare case report emphasises the significance of maintaining a high index of suspicion and implementing prompt intervention through a multidisciplinary approach. It also raises an open-ended question about whether the petrous carotid pseudoaneurysm is a complication of chronic otitis media or merely a co-incidence.

Proximal Clipping and Distal High-Flow Bypass in the Treatment of Giant/Complex Intracranial Aneurysm: An Opportunity or a Risk from a Fluid-Structural Interaction Analysis.

Conventional clipping and endovascular treatment are difficult to apply for some giant intracranial aneurysms (GIAs), and sometimes extracranial-to-intracranial (EC-IC) bypass becomes the optional choice. However, not all GIA patients can benefit from it. This study aims to recognize the underlying problems. We included eligible patients in our care. Then, we researched from three levels: a retrospective review of clinical data, fluid-structural analysis from two representative patient-specific models, and fluid-structural interaction analysis for idealized models to investigate the hemodynamic and biomechanical mechanisms. In this article, we report nine patients with GIA who underwent EC-IC surgery. Of them, three experienced dangerous postoperative hemorrhage, and one patient died. Among these three patients, two lacked the A1 segment of the anterior cerebral artery (ACA). The numerical simulation showed that after surgery, for the patient with an unruptured aneurysm and existence of ACA, the wall deformation, wall stress, pressure, and area of the oscillatory shear index (OSI) > 0.2 were decreased by 43%, 39%, 33%, and 13%, while the patient without A1 segment having postoperative hemorrhage showed 36%, 45%, 13%, and 55% increased, respectively. Thus, we postulated a dangerous "stump phenomenon" in such conditions and further demonstrated it from idealized models with different sizes of ACA. Finally, we found a larger anastomosis angle and smaller diameter of the graft can alleviate this effect. Neurosurgeon should cautiously evaluate the opportunity and risk for such patients who have aplasia of the A1 segment of ACA when making clinical decisions.

High-flow bypass for giant dolichoectatic vertebrobasilar aneurysms: illustrative cases

BACKGROUND Giant fusiform dolichoectatic vertebrobasilar artery aneurysms are challenging lesions with a poor natural history. When there is progressive brainstem compression from these lesions, endovascular treatment can be insufficient, and bypass surgery remains a possible salvage option. High-flow bypass surgery with proximal occlusion can potentially arrest aneurysm growth, promote aneurysm thrombosis, and reduce rupture risk. The authors describe their experience in two patients with giant fusiform dolichoectatic vertebrobasilar artery aneurysms treated with high-flow bypass. OBSERVATIONS Both patients presented with enlarging giant dolichoectatic vertebrobasilar aneurysms causing symptomatic brainstem compression. The authors performed staged treatment involving high-flow bypass from the external carotid artery to the posterior cerebral artery using a saphenous vein graft, Hunterian proximal vertebrobasilar occlusion, and finally posterior fossa decompression with or without direct aneurysm thrombectomy and debulking. Postoperative angiography revealed successful flow reversal, aneurysm exclusion, and no brainstem stroke. Clinically, one patient had improvement in their modified Rankin Scale (mRS) score from 3 preoperatively to 1 at 12-month follow-up. The second patient had a deterioration in their mRS score from 4 to 5 at 12-month follow-up. LESSONS High-flow bypass strategies remain high risk but can be a viable last resort in patients with neurological deficits and enlarging giant fusiform dolichoectatic vertebrobasilar artery aneurysms.

Complex M1 Middle Cerebral Artery Aneurysm Treated With High-Flow Bypass and Trapping: 2-Dimensional Operative Video.

Complex M1 Middle Cerebral Artery Aneurysm Treated With High-Flow Bypass and Trapping: 2-Dimensional Operative Video.

Alternative Bypass Technique Using Radial Artery Graft between V3 Segment of Vertebral Artery and Middle Cerebral Artery: Technical Note.

There are some cases where a radial artery (RA) graft is needed for a high-flow extracranial to intracranial (EC-IC) bypass as the external carotid artery (ECA) cannot be utilized as a donor artery. In this report, we describe two cases of extracranial vertebral artery (VA) to middle cerebral artery (MCA) high-flow bypass using an RA graft with an artificial vessel as an alternative bypass technique. The patient was placed supine with a head rotation of 80 degrees. After frontotemporal craniotomy, another C: -shaped skin incision was made at the retroauricular region and the V3 portion of the VA was exposed at the suboccipital triangle. Prior to attempting the high-flow bypass, the superficial temporal artery (STA) was anastomosed to the M4 portion of the MCA as an insurance bypass. The RA graft was anastomosed to the V3 portion of the VA that traveled under the periosteum at the supra-auricular region through an artificial vessel. After RA-M2 anastomosis, an alternative EC-IC bypass, the V3-RA-M2 bypass, was achieved. Postoperative angiography demonstrated successful graft patency and no perioperative complications were observed in both cases. In the cases where a high-flow bypass is required, the V3 portion of the VA is a suitable alternative proximal anastomosis site when the ECA is not a candidate donor. Furthermore, an artificial vessel shows satisfactory protection against graft complications.

Distal Endovascular Occlusion for Incomplete Occlusion of Cavernous Carotid Aneurysms after High-flow Bypass and Cervical Internal Carotid Artery Ligation.

Internal carotid artery (ICA) ligation for placing a high-flow extracranial-intracranial (EC-IC) bypass is used in patients with aneurysms on the cavernous portion of the ICA. Recanalization and rupture after proximal ICA ligation can occur. We present four patients who underwent endovascular distal ICA occlusion and report our surgical technique and treatment results. We ligated the ICA to place an EC-IC bypass using a radial artery (RA) graft. Failure to obtain spontaneous occlusion in the distal region required endovascular treatment an average of 219 days later. A guide catheter was placed in the common carotid artery, a guide or distal access catheter was introduced in the RA graft from the external carotid artery, and a microcatheter was navigated into the cavernous aneurysm through the RA graft. Using detachable coils, endovascular ICA occlusion was from just distal to the aneurysmal neck to a site proximal to the origin of the ophthalmic artery. Aneurysmal occlusion was completed by endovascular occlusion of the distal ICA. Complications were RA graft stenosis and transient consciousness disturbance due to local subarachnoid hemorrhage. Outpatient follow-up for a mean of 109.5 months revealed no recurrences. Distal occlusion of the ICA through the implanted RA graft is simple and presents a low risk for cerebral infarction due to thrombus formation during the procedure. To treat cavernous carotid aneurysms that do not disappear after placing the EC-IC bypass after ICA ligation at the aneurysmal neck, we offer our procedure as a treatment option.

External carotid artery-radial artery graft-posterior cerebral artery bypass for complex vertebrobasilar aneurysms: efficacy and analysis of outcome in a single center.

The purpose of this research was to demonstrate the effectiveness and clinical outcome of an external carotid artery-radial artery graft-posterior cerebral artery (ECA-RAG-PCA) bypass in the treatment of complex vertebrobasilar artery aneurysms (VBANs) in a single-center retrospective study. An ECA-RAG-PCA bypass may be a last and very important option in the treatment of complex VBANs when conventional surgical clipping or endovascular interventions fail to achieve the desired outcome. This study retrospectively analyzed the clinical presentation, case characteristics, aneurysm location, size and morphology, choice of surgical strategy, complications, clinical follow-up, and prognosis of the patients enrolled. The data involved were analyzed by the appropriate statistical methods. A total of 24 patients with complex VBANs who met the criteria were included in this study. Eighteen (75.0%) were male and the mean age was 54.1 ± 8.83years. The aneurysms were located in the vertebral artery, the basilar artery, and in the vertebrobasilar artery with simultaneous involvement. All patients underwent ECA-RAG-PCA bypass surgery via an extended middle cranial fossa approach, with 8 (33.3%) undergoing ECA-RAG-PCA bypass only, 3 (12.5%) undergoing ECA-RAG-PCA bypass combined with aneurysm partial trapping, and 12 (50.0%) undergoing ECA-RAG-PCA bypass combined with proximal occlusion of the parent artery. The average clinical follow-up was 22.0 ± 13.35months. The patency rate of the high-flow bypass was 100%. At the final follow-up, 15 (62.5%) patients had complete occlusion of the aneurysm, 7 (29.2%) patients had subtotal occlusion of the aneurysm, and 2 (8.3%) patients had stable aneurysms. The rate of complete and subtotal occlusion of the aneurysm at the final follow-up was 91.7%. The clinical prognosis was good in 21 (87.5%) patients and no procedure-related deaths occurred. Analysis of the good and poor prognosis groups revealed a statistically significant difference in aneurysm size (P = 0.034, t-test). Combining the results of this study and the clinical experience of our center, we propose a surgical algorithm and strategy for the treatment of complex VBANs.The technical approach of ECA-RAG-PCA bypass for complex VBANs remains important, even in an era of rapid advances in endovascular intervention. When conventional surgical clipping or endovascular intervention has failed, an ECA-RAG-PCA bypass plays a role that cannot be abandoned and is a very important treatment option of last resort.

Extracranial Internal Carotid Artery Aneurysm Treated with High-Flow Bypass Surgery with Radial Artery Graft

Extracranial internal carotid carotid aneurysms are rare, surgical treatment is complex if they are at the high cervical level and if the artery is tortuous. We present the case of a patient with an upper cervical internal carotid aneurysm (ICA), treated by high-flow bypass surgery, using a radial artery (RA) graft between the external carotid artery (ACE) and the middle cerebral artery (MCA).

Safety and efficacy of transgraft internal trapping after proximal internal carotid artery ligation with high-flow bypass.

Proximal internal carotid artery (ICA) ligation with high-flow bypass is an important vascular reconstructive technique for giant ICA aneurysms or skull base tumors involving the ICA to control intraoperative bleeding. Retrograde or collateral blood flow occasionally remains postoperatively and requires complete internal trapping. Although transgraft internal trapping is one of the options, there are few reports on transgraft treatment. The purpose of this study was to report our experience of transgraft internal trapping and evaluate the safety and efficacy of this procedure. We retrospectively selected patients who underwent transgraft internal trapping after proximal ICA ligation with high-flow bypass between January 2012 and June 2020. We encountered five cases of this procedure (one aneurysm case and four tumor cases). The median duration between the bypass and transgraft internal trapping was 12 days. In four out of five cases, a guiding catheter could be placed in the graft. No disruption of the anastomosis was observed. Transgraft internal trapping was achieved in all five cases with detachable coils. All treatments could be completed safely without any adverse events, including ischemic and hemorrhagic complications. Transgraft internal trapping after proximal ICA ligation with high-flow bypass may be an option for preventing residual retrograde blood flow.

Successful treatment with urgent revascularization and parent artery occlusion for a ruptured intratumoral aneurysm following prior meningioma surgery: illustrative case.

An intratumoral aneurysm encased within the associated intracranial tumor is rare, and hemorrhage caused by its rupture is even more rare. While urgent and adequate surgical treatment is important, the treatment can be difficult given the limited understanding of this rare condition. A 69-year-old man who had undergone meningioma surgery 30 years prior presented with a disturbance in consciousness. Magnetic resonance imaging revealed massive intracerebral and subarachnoid hemorrhage. A round, partially calcified mass, which was diagnosed as recurrent meningioma, was also observed. Subsequent cerebral angiography revealed that the source of the hemorrhage was an intratumoral aneurysm in the dorsal internal carotid artery (ICA) encased within the recurrent meningioma. Urgent surgical ICA trapping and high-flow graft bypass were conducted. The postoperative course was uneventful, and he was referred to another hospital for rehabilitation. This is the first case report of a ruptured intratumoral aneurysm being treated with urgent combined revascularization and parent artery trapping surgery. This surgical approach may be a feasible treatment option for such a challenging condition. Additionally, this case highlights the importance of diligent long-term follow-up after skull-base surgery, as minor intraoperative vascular wall injury may trigger the development and rupture of an intracerebral aneurysm.

Technical advantages of a novel flow diverter in complex flow diversion: patient series.

The Surpass Streamline flow diverter (SSFD) possesses 4 attributes that may offer an important advantage in the treatment of complex pathologies: (1) utilization of an over-the-wire (OTW) delivery system, (2) greater device length, (3) larger potential diameter, and (4) propensity to open in tortuosity. Case 1 leveraged device diameter to embolize a large, recurrent vertebral artery aneurysm. Angiography at 1 year posttreatment showed complete occlusion with a patent SSFD. Case 2 leveraged device length and opening in tortuosity to manage a symptomatic 20-mm cavernous carotid aneurysm. Magnetic resonance imaging at 2 years demonstrated aneurysm thrombosis and patent stents. Case 3 utilized diameter, length, and the OTW delivery system to treat a giant intracranial aneurysm previously treated with surgical ligation and a high-flow bypass procedure. Angiography at 5 months postprocedure demonstrated the return of laminar flow, as the vein graft had healed around the stent construct. Case 4 used diameter, length, and the OTW system to treat a giant, symptomatic, dolichoectatic vertebrobasilar aneurysm. Twelve-month follow-up imaging revealed a patent stent construct with no change to the aneurysm size. Increased awareness of the unique attributes of the SSFD may allow a larger number of cases to be treated with the proven mechanism of flow diversion.

Cerebral revascularization for complex middle cerebral artery aneurysms: surgical strategies and outcomes in a single center

Cerebral revascularization is the ultimate treatment for a subset of complex middle cerebral artery (MCA) aneurysms. The decision for the revascularization strategy should be made during the treatment process. This study aimed to summarize the revascularization strategies for different types of complex MCA aneurysms and their outcomes. The clinical data of patients with complex MCA aneurysms who underwent cerebral revascularization since 2015 were analyzed retrospectively. The aneurysms were classified according to the location and other main characteristics that affect the selection of surgical modalities. The corresponding surgical modalities and treatment outcomes were summarized. A total of 29 patients with 29 complex MCA aneurysms were treated with cerebral revascularization from 2015 to 2022. Treated aneurysms were located at the prebifurcation segment in 7 patients, bifurcation segment in 12 patients, and postbifurcation segment in 10 patients. Surgical modalities in the prebifurcation segment included four high-flow extracranial-to-intracranial (EC-IC) bypasses with aneurysm trapping or proximal occlusion, two IC-IC bypasses with aneurysm excision, and one combination bypass with aneurysm excision. In the bifurcation segment, surgical modalities included two low-flow EC-IC bypasses with aneurysm excision or trapping, six IC-IC bypasses with aneurysm excision, three combination bypasses with aneurysm excision, and one constructive clipping with IC-IC bypass. In the postbifurcation segment, surgical modalities included nine IC-IC bypasses with aneurysm excision and low-flow EC-IC bypass with aneurysm trapping. The revascularization strategy for prebifurcation aneurysms was determined based on the involvement of lenticulostriate arteries, whereas the strategy for bifurcation aneurysms was determined based on the number of distal bifurcations and the shape of the aneurysm. The location of the aneurysm determined the revascularization strategy for aneurysms in the postbifurcation segments. Angiography demonstrated that aneurysms were completely obliterated in 26 cases and shrank in 3 cases, and all bypasses except one were patent. The mean follow-up period was 47.5months. Three patients developed hemiplegic paralysis, and one developed transient aphasia postoperatively due to cerebral ischemia. No new neurological dysfunction occurred in the other 25 patients with no recurrence or enlargement of aneurysms during the follow-up. Prebifurcation aneurysms involving the lenticulostriate arteries require proximal occlusion with high-flow bypass. Most of the other aneurysms can be safely excised or trapped by appropriate revascularization strategies according to their location and orientation.

Incidence of Acute Neurological Events in Neonates and Infants Undergoing Cardiac Surgery Using a High-Hematocrit/ High-Flow Bypass Strategy.

Background: The incidence of new acute neurological injury occurring in neonates and infants during cardiac surgery utilizing cardiopulmonary bypass is reportedly 3% to 5%. In 2013, we adopted a high flow rate, and high hematocrit bypass strategy, and sought to assess the incidence of early neurological injuries associated with this strategy. Methods: Neonates and infants undergoing cardiopulmonary bypass between January 2013 and December 2019 (n = 714) comprise the study. Adverse neurological events (ANEs) were defined as any abnormality of pupils, delayed awakening, seizures, focal neurological deficits, concerns prompting neurological consultation, or any abnormality on neurological imaging in the postoperative period. Our bypass strategy included a high flow rate (150-200 mL/kg/min), without reduction of flow rates during cooling and maintaining a target hematocrit on bypass > 32% with a terminal hematocrit of > 42%. Results: Median weight at the time of the procedure was 4.6 kg (IQR 3.6-6.1 kg) with the smallest patient weighing 1.36 kg. There were 46 premature patients (6.4%). There were 149 patients (20.9%) patients who underwent deep hypothermic circulatory arrest with a median time of 26 min (IQR 21-41 min). Hospital mortality was 3.5% (24/714, 95% CI: 2.28-5.13). The incidence of neurological events as defined above was 0.84% (6/714, 95% CI: 0.31-1.82). Neurological imaging identified ischemic injury in 4 patients and intraventricular hemorrhage in 2. Conclusions: High flow/high hematocrit bypass strategy was associated with a low incidence of ANE in this vulnerable population.

Microsurgical Treatment of a Giant Intracavernous Carotid Artery Aneurysm in a Pediatric Patient. Case Report and Literature Review

Introduction: Intracranial aneurysms in pediatric age represent 4 - 5% of all cases, and 20% are giant (>25mm). The main sites of occurrence are ICA and MCA; about 55% - 72.5% of cases present rupture and secondary SAH with a 10% - 23% mortality. Case Description: We report the case of a previously healthy nine-year-old woman that initiated severe right retroocular pain and holocraneal headache. Her relatives detected paresis of the III, IV, and VI cranial nerves three days later. After evaluation, an MRI showed the presence of a giant aneurysm in the cavernous portion of the internal carotid artery (ICA) with a mass effect. The patient was treated surgically through a high-flow bypass using a radial artery graft and trapping of the aneurysm. The patient had an uneventful postoperative course and was discharged three days after the operation to continue in follow-up at the outpatient clinic. Discussion: The options for treatment are endovascular treatment through flow diverters or stenting and coiling, with the risk of incomplete occlusion or thrombosis. On the other hand, the goal of surgery is the permanent occlusion through the proximal closure of the ICA if a balloon occlusion test shows good collateral circulation or by trapping the aneurysm combined with a high-flow bypass if the collateral circulation is not good or absent. Conclusion: Even when the surgical option was successful in this case, there is no consensus about the best treatment; the selection of the method to use in these aneurysms depends on the center´s experience when confronting this rare entity.

High Flow Bypass and Trapping of the Fusiform Aneurysm of Right Middle Cerebral Artery Using Y Graft: A Noble Surrogate

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A challenging case of recurrent and progressive fusiform anterior circulation intracranial aneurysms: illustrative case.

Intracranial fusiform aneurysms are circumferential dilations of cerebral arteries that can lead to complications including ischemic stroke due to vessel occlusion, subarachnoid hemorrhage, or intracerebral hemorrhage. Treatment options for fusiform aneurysms have expanded significantly in recent years. Microsurgical treatment options include proximal and distal surgical occlusion and microsurgical trapping of the aneurysm, usually in association with high-flow bypass procedures. Endovascular treatment options include the placement of coils and/or flow diverters. Here the authors report a case of aggressive surveillance and treatment of a man with multiple progressive, recurrent, and de novo fusiform aneurysms of the left anterior cerebral circulation over 16 years. Because the long-term course of his treatment coincided with the recent expansion of endovascular treatment options, he underwent every type of treatment listed above. This case demonstrates the wide range of therapeutic options for fusiform aneurysms and how the treatment model for these lesions has evolved.

High-flow Bypass with Proximal Artery Occlusion as a Therapeutic Option for Recurrent Large Internal Carotid Paraclinoid Aneurysm after Endovascular Surgery

High-flow Bypass with Proximal Artery Occlusion as a Therapeutic Option for Recurrent Large Internal Carotid Paraclinoid Aneurysm after Endovascular Surgery