Assessment of changes in vessel area during needle manipulation in microvascular anastomosis using a deep learning-based semantic segmentation algorithm: A pilot study.

Appropriate needle manipulation to avoid abrupt deformation of fragile vessels is a critical determinant of the success of microvascular anastomosis. However, no study has yet evaluated the area changes in surgical objects using surgical videos. The present study therefore aimed to develop a deep learning-based semantic segmentation algorithm to assess the area change of vessels during microvascular anastomosis for objective surgical skill assessment with regard to the "respect for tissue." The semantic segmentation algorithm was trained based on a ResNet-50 network using microvascular end-to-side anastomosis training videos with artificial blood vessels. Using the created model, video parameters during a single stitch completion task, including the coefficient of variation of vessel area (CV-VA), relative change in vessel area per unit time (ΔVA), and the number of tissue deformation errors (TDE), as defined by a ΔVA threshold, were compared between expert and novice surgeons. A high validation accuracy (99.1%) and Intersection over Union (0.93) were obtained for the auto-segmentation model. During the single-stitch task, the expert surgeons displayed lower values of CV-VA (p < 0.05) and ΔVA (p < 0.05). Additionally, experts committed significantly fewer TDEs than novices (p < 0.05), and completed the task in a shorter time (p < 0.01). Receiver operating curve analyses indicated relatively strong discriminative capabilities for each video parameter and task completion time, while the combined use of the task completion time and video parameters demonstrated complete discriminative power between experts and novices. In conclusion, the assessment of changes in the vessel area during microvascular anastomosis using a deep learning-based semantic segmentation algorithm is presented as a novel concept for evaluating microsurgical performance. This will be useful in future computer-aided devices to enhance surgical education and patient safety.

Surgical and endovascular cerebral revascularization for cerebral vasculitis with inflammatory vessel stenosis: a case series.

Autoimmune vasculitides affect the cerebral vasculature significantly in a considerable number of cases. When immunosuppressive treatments fail to prevent stenosis in cerebral vessels, treatment options for affected patients become limited. In this case series, we present four cases of pharmacoresistant vasculitis with recurrent transient ischemic attacks (TIAs) or stroke successfully treated with either extracranial-intracranial (EC-IC) bypass surgery or endovascular stenting. Both rescue treatments were effective and safe in the selected cases. Our experience suggests that cases of pharmacoresistant cerebral vasculitis with recurrent stroke may benefit from rescue revascularization in combination with maximum medical management.

Deep learning-based video-analysis of instrument motion in microvascular anastomosis training.

PURPOSE: Attaining sufficient microsurgical skills is paramount for neurosurgical trainees. Kinematic analysis of surgical instruments using video offers the potential for an objective assessment of microsurgical proficiency, thereby enhancing surgical training and patient safety. The purposes of this study were to develop a deep-learning-based automated instrument tip-detection algorithm, and to validate its performance in microvascular anastomosis training. METHODS: An automated instrument tip-tracking algorithm was developed and trained using YOLOv2, based on clinical microsurgical videos and microvascular anastomosis practice videos. With this model, we measured motion economy (procedural time and path distance) and motion smoothness (normalized jerk index) during the task of suturing artificial blood vessels for end-to-side anastomosis. These parameters were validated using traditional criteria-based rating scales and were compared across surgeons with varying microsurgical experience (novice, intermediate, and expert). The suturing task was deconstructed into four distinct phases, and parameters within each phase were compared between novice and expert surgeons. RESULTS: The high accuracy of the developed model was indicated by a mean Dice similarity coefficient of 0.87. Deep learning-based parameters (procedural time, path distance, and normalized jerk index) exhibited correlations with traditional criteria-based rating scales and surgeons' years of experience. Experts completed the suturing task faster than novices. The total path distance for the right (dominant) side instrument movement was shorter for experts compared to novices. However, for the left (non-dominant) side, differences between the two groups were observed only in specific phases. The normalized jerk index for both the right and left sides was significantly lower in the expert than in the novice groups, and receiver operating characteristic analysis showed strong discriminative ability. CONCLUSION: The deep learning-based kinematic analytic approach for surgical instruments proves beneficial in assessing performance in microvascular anastomosis. Moreover, this methodology can be adapted for use in clinical settings.

Double-barreled IMA-M2 and STA-MCA bypass in severe stenosis of terminal internal carotid artery: three case reports.

EC-IC bypasses have been performed to treat complex aneurysms or moyamoya disease or atherosclerotic steno-occlusive disease. We report the three cases that underwent EC-IC revascularization of the IMA-M2 bypass using the radial artery graft concurrently after the STA-MCA anastomosis to prevent potential ischemic damage during the operation and augment more flow in terminal internal carotid artery stenosis. All patients experienced neither perioperative complications nor further events for a 3-month follow-up. The double-barreled IMA-M2 and STA-MCA bypass is a good option for substantial amount of EC-IC revascularization with minimizing ischemic injury and maximizing flow amount in patients with severe hemodynamic compromise.

Usefulness of the Lone Star Retractor System for harvesting the superficial temporal artery: technical note.

Harvesting the superficial temporal artery (STA) is the first difficult step in extracranial-intracranial bypass surgery. There are various methods and instruments for harvesting the STA. We used the Lone Star (LS) retractor system for harvesting the STA. The LS retractor system is used in other surgical specialties. The LS retractor system consists of the retractor ring (14.1 cm × 14.1 cm) and elastic stays (5-mm sharp hook). The retractor ring can be used to adjust to the operative field. Retracting the loose connective tissue around the STA by the elastic stays can make harvesting the STA easy and safe. After harvesting the STA, retracting the skin and muscle by the elastic stays is useful for hemostasis during intracranial surgery and anastomosis. We used the LS retractor system in 26 consecutive patients to perform STA-MCA anastomosis between November 2015 and August 2018. All STAs were harvested without complications or injuries. The LS retractor system is a safe and useful method for harvesting the STA.

Ischemic Stroke Revascularization.

Extracranial-intracranial (EC-IC) bypass is one of the most fundamental techniques for ischemic cerebrovascular disease (CVD). We describe the standard surgical strategies, advanced techniques, and controversies concerning revascularization of ischemic stroke. The standard surgical strategies and techniques emphasize how to determine surgical indication, which should be decided for symptomatic internal carotid artery or middle cerebral artery (MCA) occlusive disease with misery perfusion detected by quantitative single photon emission computed tomography. Advanced techniques are available for complex situations such as posterior circulation revascularization, Bonnet bypass for common carotid artery obstruction, and various EC-IC bypasses for ischemia in the MCA and/or anterior cerebral artery territories using inter-grafts such as femoral veins and radial arteries, illustrated by our surgical results and experiences. Controversies include endovascular treatment complementary to EC-IC bypass. Finally, we advocate emergent EC-IC bypass for progressive ischemic CVD, particularly for contraindication or unsuccessful treatment after intravenous tissue plasminogen activator administration and/or endovascular thrombolysis. EC-IC bypass surgery can be reliable for ischemic CVD under strict optimal surgical indications using safe and reliable surgical techniques.

[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.

External carotid artery to internal carotid artery transposition to augment flow for a superficial temporal artery to middle cerebral artery bypass associated with severe external carotid artery stenosis.

BACKGROUND: Donor vessel quality can impact the outcome of extracranial-intracranial (EC-IC) bypass. External carotid artery (ECA) disease may produce embolism into the anastomosis and cerebral territory and possibly reduce flow in the superficial temporal artery (STA). Previously reported remedies to ECA stenosis include ECA endarterectomy, stenting, and angioplasty. Clinical presentation A middle-aged patient with chronic left MCA occlusion, progressive ischemic symptoms on maximal medical therapy, and imaging confirmation of compromised hemodynamic reserve was evaluated for EC-IC bypass. Angiography demonstrated severe ECA origin stenosis. An ECA-ICA transposition was performed, primarily to eliminate the risk of emboli and secondarily to possibly improve the STA flow. The patient sustained an excellent radiological and clinical outcome, and the STA donor cut-flow was increased modestly by 22% (45 to 55 mL/min). CONCLUSION: This case is the first report of an ECA to internal carotid artery transposition as an option in the management of ECA stenosis in preparation for an STA-MCA bypass for the purpose of flow augmentation.

STA-enhanced vascularized galeal flap for revascularization of moyamoya disease: technical report.

BACKGROUND: A variety of revascularization techniques have been reported for the management of moyamoya disease to prevent risks of stroke. STA (superficial temporal artery)-MCA (middle cerebral artery) microanastomosis, single or double bypass, with temporal muscle or galeal onlay graft has been the standard operative procedure. METHOD: Our rationale of revascularization surgery has been a combination of STA-MCA double bypass using the frontal and the parietal branches of STA and transfer of a highly vascularized thick galeal flap with maintained STA vasculature. CONCLUSION: This STA-enhanced vascularized galeal flap graft is extremely effective for revascularization of moyamoya disease.

Clinical factors influencing the development of extracranial-intracranial bypass graft for steno-occlusive cerebrovascular disease.

OBJECTIVEEffectively retaining the patency of the extracranial-intracranial (ECIC) bypass is one of the most important factors in improving long-term results; however, the factors influencing bypass patency have not been discussed much. Therefore, the authors investigated factors influencing the development of the bypass graft.METHODSIn this retrospective study, the authors evaluated 49 consecutive hemispheres in 47 adult Japanese patients who had undergone ECIC bypass for chronic steno-occlusive cerebrovascular disease. To evaluate objectively the development of the ECIC bypass graft, the change in the area of the main trunk portion of the superficial temporal artery (STA) from before to after bypass surgery (postop/preop STA) was measured. Using the interquartile range (IQR), the authors statistically analyzed the factors associated with excellent (> 3rd quartile) and poor development (< 1st quartile) of the bypass graft.RESULTSThe postop/preop STA ranged from 1.08 to 6.13 (median 1.97, IQR 1.645-2.445). There was a significant difference in the postop/preop STA between the presence and absence of concurrent diabetes mellitus (p = 0.0432) and hyperlipidemia (0.0069). Furthermore, logistic regression analysis revealed that only concurrent diabetes mellitus was significantly associated with poor development of the bypass graft (p = 0.0235).CONCLUSIONSDiabetes mellitus and hyperlipidemia influenced the development of the ECIC bypass graft. In particular, diabetes mellitus is the only factor associated with poor development of the bypass graft.

Feasibility and safety of intraoperative BOLD functional MRI cerebrovascular reactivity to evaluate extracranial-to-intracranial bypass efficacy.

Blood oxygenation level-dependent functional MRI cerebrovascular reactivity (BOLD-CVR) is a contemporary technique to assess brain tissue hemodynamic changes after extracranial- intracranial (EC-IC) bypass flow augmentation surgery. The authors conducted a preliminary study to investigate the feasibility and safety of intraoperative 3-T MRI BOLD-CVR after EC-IC bypass flow augmentation surgery. Five consecutive patients selected for EC-IC bypass revascularization underwent an intraoperative BOLD-CVR examination to assess early hemodynamic changes after revascularization and to confirm the safety of this technique. All patients had a normal postoperative course, and none of the patients exhibited complications or radiological alterations related to prolonged anesthesia time. In addition to intraoperative flow measurements of the bypass graft, BOLD-CVR maps added information on the hemodynamic status and changes at the brain tissue level. Intraoperative BOLD-CVR is feasible and safe in patients undergoing EC-IC bypass revascularization. This technique can offer immediate hemodynamic feedback on brain tissue revascularization after bypass flow augmentation surgery.

Role of botulinum neurotoxin-A in cerebral revascularization graft vasospasm prevention: current state of knowledge.

Graft stenosis and occlusion remain formidable complications in cerebral revascularization procedures, which can lead to significant morbidity and mortality. Graft vasospasm can result in early postoperative graft stenosis and occlusion and is believed to be at least partially mediated through adrenergic pathways. Despite various published treatment protocols, there is no single effective spasmolytic agent. Multiple factors, including anatomical and physiological variability in revascularization conduits, patient age, and comorbidities, have been associated with graft vasospasm pathogenesis and response to spasmolytics. The ideal spasmolytic agent thus likely needs to target multiple pathways to exert a generalizable therapeutic effect. Botulinum toxin (BTX)-A is a powerful neurotoxin widely used in clinical practice for the treatment of a variety of spastic conditions. Although its commonly described paradigm of cholinergic neural transmission blockade has been widely accepted, evidence for other mechanisms of action including inhibition of adrenergic transmission have been described in animal studies. Recently, the first pilot study demonstrating clinical use of BTX-A for cerebral revascularization graft spasm prevention has been reported. In this review, the mechanistic basis and potential future clinical role of BTX-A in graft vasospasm prevention is discussed.

Early and midterm results of treatment of giant internal carotid artery paraclinoid aneurysms with trapping and flow diverters.

BACKGROUND: Flow diverter devices (FDD) carry risks of postoperative complications when treating aneurysms with wide necks, stenosis, and severe tortuosity of the parent vessel. In this study, we evaluated early and midterm results for the treatment of giant paraclinoid aneurysms managed by trapping and endovascular deployment of FDD. METHODS: Medical records were analyzed for patients with giant paraclinoid aneurysms treated between July 2008 and December 2017 at National Centre for Neurosurgery with either a flow diverter or by trapping the aneurysm with or without extracranial-intracranial (EC-IC) bypass surgery. We recorded age, sex, clinical presentation, treatment modality, morbidity, and mortality. Clinical outcomes were assessed using a modified Rankin scale (mRS). RESULTS: Among 29 consecutive patients, 13 were treated with FDD, and 16 patients were managed by trapping the aneurysm, where 7/16 cases had preliminary EC-IC bypass. Of 16 trapping patients, six were trapped endovascularly and ten were trapped surgically. During the follow-up period (mean 33 months, range 6-96), total exclusion of the aneurysm from the circulation was observed 100% of aneurysms in the trapping group and 84.6% in the FDD group (P = 0.192). Early postoperative morbidity was observed in three (23%) cases in the FDD group, and four (25%) in trapping group (P = 0.525). The FDD group had one (7.7%) fatal complication due to stent occlusion and severe ischemic stroke after three months postoperatively, despite appropriate antiplatelet therapy. There were no mortalities in the trapping group (P = 0.149). The rate of mRS 0-2 did not differ significantly across groups at discharge (81.3% vs. 69.2%; P = 0.667), and all patients had mRS 0-2 at follow-up (P = 1.000). CONCLUSIONS: FDD deployment for giant paraclinoid aneurysms results in comparable angiographic and clinical outcomes to aneurysm trapping. Despite implementation of modern endovascular treatment methods, aneurysm trapping remains a valuable treatment option in carefully selected patients with giant paraclinoid aneurysms.

Long-Term Effects on Preventing Stroke after Endovascular Treatment or Bypass Surgery for Intracranial Arterial Stenosis.

BACKGROUND: Intracranial arterial stenosis (ICAS) is an important cause of ischemic stroke worldwide due to its higher risk of recurrence with medical therapy. Although some large randomized studies failed to show the superiority of surgical treatment compared with medical therapy, the results of medical therapy are not sufficient. There are patients who still benefit from surgical treatment. This retrospective analysis aimed to evaluate the long-term efficacy of surgical therapy with percutaneous transluminal angioplasty and/or stenting (PTA/PTAS) or extracranial-intracranial (EC/IC) bypass surgery for patients with ICAS. METHODS: Between October 2005 and December 2016, 55 ICAS patients were treated with PTA/PTAS or EC-IC bypass surgery. Their electronic medical records were retrospectively reviewed and analyzed. The primary outcome was all adverse events beyond 30 days after a revascularization procedure. RESULTS: We performed 21 cases (35%) of PTA, 4 cases (7%) of PTAS, and 34 cases (58%) of EC-IC bypass surgery and the median follow-up duration was 66 months (range 1-144 months). The occurrence rate of the primary outcome was 10.2% and only 1 patient (1.8%) experienced ipsilateral disabling ischemic stroke beyond 30 days. The long-term functional independent survival rate was 83.6%. CONCLUSIONS: We demonstrated a long-term favorable outcome of combined surgical intervention for ICAS patients with PTA/PTAS and EC-IC bypass surgery, and the result was better than previously reported outcomes of medical therapy. Additional multicenter studies are required to draw firm conclusions on the efficacy of reduction of recurrent stroke in patients with ICAS.

[Successful combination treatment of giant bicameral fusiform partially thrombosed vertebral artery aneurysm at 12-year-old patient (practical case and literature review)]. / Uspeshnoe kombinirovannoe lechenie gigantskoi dvukhkamernoi fuziformnoi chastichno trombirovannoi anevrizmy pozvonochnoi arterii u patsienta 12 let (sluchai iz praktiki i obzor literatury).

Giant cerebral aneurysms are diagnosed more often in children than in adults. Treatment of giant aneurysms is carried out both by endovascular and microsurgical methods. Literature information on combination of microsurgical and endovascular operations of cerebral aneurysms at children is little. A clinical case of the combined treatment of a giant bicameral fusiform partially thrombosed aneurysm of the right vertebral artery at a 12-year-old patient and a literature review on this topic are presented. The patient underwent several complex neurosurgical interventions during two operations: 1) microsurgery including revascularization of the right posterior lower cerebellar artery, thrombectomy and trapping of the larger chamber of fusiform aneurysm of the right vertebral artery, and 2) endovascular, which consists in the installation of redirecting stent from the left vertebral artery to main artery. The uniqueness of the case which we presented lies in the fact that the tactics of stage combined treatment for a complex aneurysm at child was originally planned and successfully implemented. The treatment allowed to ensure a complete shutdown of aneurysm and to exclude postoperative cerebral complications.

EC-IC bypass for cerebral revascularization following skull base tumor resection: Current practices and innovations.

Complex skull base tumors can involve critical vessels of the head and neck. To achieve a gross total resection, vessel sacrifice may be necessary. In cases where vessel sacrifice will cause symptomatic cerebral ischemia, surgical revascularization is required. The purpose of this paper is to review cerebral revascularization for skull base tumors, the indications for these procedures, outcomes, advances, and future directions.

Preclinical success but clinical failure of the sutureless excimer laser-assisted non-occlusive anastomosis (SELANA) slide.

BACKGROUND: The excimer laser-assisted non-occlusive anastomosis (ELANA) has been developed for intracranial bypass without the need for temporary recipient occlusion. We designed and tested a sutureless variant of the ELANA-the SELANA slide (SEsl). OBJECTIVE: This study aims to evaluate the SEsl preclinical results and describe its first clinical application. METHODS: First, in a cadaver study, 28 SEsl anastomoses were compared with 28 ELANA anastomoses. Second, in an acute rabbit model, 90 SEsl anastomoses were compared with 30 ELANA anastomoses. Finally, in a surviving pig model, 38 SEsl bypasses were created. To evaluate the clinical efficacy of the SEsl, we then treated one patient with a giant, right-sided middle cerebral artery (MCA) aneurysm with an intracranial-intracranial SEsl bypass and parent vessel occlusion. RESULTS: In preclinical studies, the SEsl anastomosis was shown to be equivalent or superior to the ELANA in terms of associated ease, patency, and bleeding complications. However, clinical application in rigid and arteriosclerotic receiving arteries was problematic. Although bypass creation and aneurysm occlusion were technically successful and the patient was postoperatively well, a pseudoaneurysm formed postoperatively at the internal carotid artery anastomosis and bled. Subsequent treatment failed and the patient did not survive. CONCLUSION: The SEsl showed promising preclinical results across three models. However, in its present form, it is not suitable for clinical application. TRIAL NUMBER: IRB UMCU 10/154.

Microsurgical anatomy of the maxillary artery for extracranial-intracranial bypass in the pterygopalatine segment of the maxillary artery.

The extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC-IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension-free EC-IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC-IC bypass. Clin. Anat. 31:724-733, 2018. © 2017 Wiley Periodicals, Inc.

Neurocognitive Performance After Cerebral Revascularization in Adult Moyamoya Disease.

BACKGROUND AND PURPOSE: Cerebral revascularization using EC-IC bypass is widely used to treat moyamoya disease, but the effects of surgery on cognition are unknown. We compared performance on formal neurocognitive testing in adults with moyamoya disease before and after undergoing direct EC-IC bypass. METHODS: We performed a structured battery of 13 neurocognitive tests on 84 adults with moyamoya disease before and 6 months after EC-IC bypass. The results were analyzed using reliable change indices for each test, to minimize test-retest variability and practice effects. RESULTS: Twelve patients (14%) showed significant decline postoperatively, 9 patients (11%) improved, and 63 patients (75%) were unchanged. Similar results were obtained when the analysis was confined to those who underwent unilateral (33) or bilateral (51) revascularization. CONCLUSIONS: The majority of patients showed neither significant decline nor improvement in neurocognitive performance after EC-IC bypass surgery. Uncomplicated EC-IC bypass seems not to be a risk factor for cognitive decline in this patient population.

Bilateral Internal Carotid Artery Aneurysms at the Subpetrosal Portion with Unilateral Lower Cranial Nerve Palsies: Review and Consideration of Surgical Strategy.

BACKGROUND: Symptomatic bilateral extracranial internal carotid artery (ICA) aneurysms at the subpetrosal portion are extremely rare, and their treatment strategy remains unknown. CLINICAL PRESENTATION: A 42-year-old man presented to our hospital with a 2-month history of sudden onset of hoarseness, dysarthria, and dysphagia. Magnetic resonance imaging, magnetic resonance angiography, and computed tomography angiography revealed extracranial bilateral ICA aneurysms at the subpetrosal portion. The left-sided aneurysm compressed the left-sided lower cranial nerves (IX, X, XI, and XII), whereas the right-sided aneurysm was asymptomatic. We prioritized the treatment of the right-sided aneurysm to prevent bilateral lower cranial nerve deficits. This strategy was used because aneurysm treatment is not guaranteed to cure the left-sided cranial nerve palsies that lasted for 2 months. The right-sided ICA aneurysm was treated with ICA ligation and high-flow extracranial-intracranial bypass using the radial artery as bypass graft. Stent-assisted coil embolization was performed to the left-sided ICA aneurysm after 17 days. The patient showed no right-sided symptoms, and his left-sided symptoms remarkably improved 1 year after surgery. CONCLUSION: Our unique surgical strategy of prioritizing the aneurysm on the "asymptomatic" side may be one of the best treatment approaches in an extremely rare bilateral aneurysm case.