Ruptured aneurysm in collateral arteries with blood-flow impairment of posterior inferior cerebellar artery: a report of three cases.

Herein, we report three cases of cerebellar hemorrhage due to a ruptured small aneurysm located on a collateral artery compensating for one or more stenotic or occluded major cerebellar arteries. In each case, endovascular distant parent artery occlusion of both the collateral artery and aneurysm was performed to prevent rebleeding. A ruptured small aneurysm in a collateral artery may be observed in patients with hemorrhage in an atypical cerebellar region, especially in cases of stenosis or occlusion of the vertebral artery or posterior inferior cerebellar artery. Thus, cerebral angiography is recommended to rule out collateral artery aneurysm.

[Preoperative Simulation for Complication Control in Spinal Surgery].

The craniovertebral junction not only contains anatomically important structures such as the medulla oblongata, upper cervical spinal cord, and vertebral artery, but also controls the dynamic movements of flexion, extension, and rotation of the head and neck. Consequently, instability and spinal deformities can easily occur in the craniovertebral region, and appropriate treatment should be selected based on the specificity of the lesion. Basilar invagination often involves bone and vascular anomalies and fusion surgery is often required. Therefore, careful pre-operative simulations are necessary. The creation and use of three-dimensional bone models, including image navigation, are useful for surgical simulation.

Hybrid surgery of vertebral artery transposition combined with scallop and fenestration technique for the repair of type B aortic dissection patient with isolated left vertebral artery: A case report.

RATIONALE: Acute type B aortic dissection (ABAD) is a fatal cardiovascular disease with high morbidity and mortality. Isolated left vertebral artery (ILVA) is a rare aortic arch mutation originating from the aortic arch. The simultaneous occurrence of both increases the complexity and difficulty of thoracic endovascular aortic repair. However, there have been few reports on the recommendation of thoracic endovascular aortic repair treatment strategies for aortic dissection patients concomitant ILVA with insufficient landing zone. Here, we report a case of ABAD combined with ILVA treated with hybrid surgery of left vertebral artery transposition alliance with Scallop and in vivo fenestration endograft. PATIENT CONCERNS: A 38-year-old middle-aged man was transferred to our vascular department with persistent pain in his lower abdomen for 8 hours. DIAGNOSES: Preoperative computed tomography angiogram of the thoracic and abdominal aorta diagnosed with ABAD accompanied with ILVA. INTERVENTIONS: Hybrid surgery of left vertebral artery transposition alliance with Scallop and in situ fenestration endograft for revascularization of ILVA, left subclavian artery, and left common carotid artery. OUTCOMES: The hybridization operation was successfully completed. There were no complications of cerebral and spinal cord ischemia after operation. Computed tomography angiogram examination indicated no internal leakage existed in the stent and patency of the arch vessels and the transposed left vertebral artery follow-up 3 months after surgery. LESSONS: This study gave us experience in the treatment of aortic dissection with left vertebral artery variation and suggested that left vertebral artery transposition combined with scallop and in vivo fenestration stent is safe and effective.

Effects and safety of endovascular recanalization for non-acute symptomatic intracranial vertebral artery occlusion with different risks.

There is no consensus on the optimal treatment for non-acute symptomatic intracranial vertebral artery occlusion, and endovascular recanalization is a challenging procedure. We report our clinical experience of endovascular recanalization in patients with non-acute symptomatic intracranial vertebral artery occlusion to assess the feasibility and safety of endovascular recanalization and determine the candidate patients for this procedure. Ninety-two patients with non-acute symptomatic intracranial vertebral artery occlusion who underwent endovascular recanalization from January 2019 to December 2021 were retrospectively analyzed. we grouped all patients according to imaging examination findings, occlusion length, duration, nature, calcification, and angulation to evaluate the risk of endovascular recanalization. The overall success rate of endovascular recanalization was 83.7% (77/92), and the perioperative complication rate was 10.9% (10/92). Among the 3 classification groups, the recanalization success rate gradually decreased from the low-risk group to the high-risk group (low-risk: 100%, medium-risk: 93.3%, high-risk group: 27.8%, P = .047), while the overall perioperative complication rate showed the opposite trend (0%, 10.0%, 38.9%, respectively, P = .001); the proportion of patients with 90-day modified Rankin Scale scores of 0-2 decreased successively (100%, 83.3%, and 22.2%, respectively, P < .026); 77 patients with successful recanalization were followed; the rate of restenosis/reocclusion increased sequentially (0%, 17.9%, and 80%, respectively, P = .000). Patients in the low- and medium-risk groups showed a good clinical course after endovascular recanalization. Among 88 patients (four patients lost to follow-up), with a median clinical follow-up of 13 months (interquartile range », 7-16), the rate of stroke or death after 30 days was 17.4% (16/92). Endovascular recanalization is safe and feasible for low- and medium-risk patients with non-acute symptomatic intracranial vertebral artery occlusion; it is also an alternative to conservative therapy for the patients.

Utilizing physician modified fenestration on the castor branched stent technique for reconstruction of an isolated left vertebral artery on the aortic arch.

The study aimed to provide physician modified fenestration (PMF) on a single-branched stent for the aortic arch (Castor) to protect the isolated left vertebral artery (ILVA) during thoracic endovascular aortic repair (TEVAR). Patients who underwent TEVAR involving ILVA reconstruction through PMF performing on the Castor branched stent were included in a retrospective, multi-centre study from June 2018 to December 2022. In these patients, all proximal landing zones of "Castor" were positioned in Ishimaru zone 2a. A total of twenty-five patients met the inclusion criteria and the achievement rate showed 25/25 (100%) success in them. The twenty-five patients had a median follow-up length of 28.5 ± 14.6 months. One patient (4.0%) suffered from postoperative ischemic stroke before discharge. One patient (4.0%) died from a hemodialysis-related brain hemorrhage before discharge on the 29th day after the procedure. One patient died of advanced liver cancer in the 33th month after discharge. Aortic rupture, stroke or spinal cord injury did not occur throughout the follow-up period after discharge. Two patients (8.0%) experienced endoleak at the fenestration, however, resulting in only one's necessity for reintervention. Notably, the procedure effectively maintained ILVAs patency for all patients during follow up. According to our preliminary findings, performing a TEVAR under local anaesthesia using PMF on a Castor branched stent for ILVA preservation appeared practical, secure, and effective.

Transcervical Vertebral Artery Origin Endarterectomy for Vertebrobasilar Insufficiency.

Vertebral artery (VA) stenosis is a cause of vertebrobasilar insufficiency (VBI) and disabling posterior circulation stroke,1 accounting for up to 30% of all strokes.2 Although the natural history of VBI is not as well delineated as that of carotid stenosis, strokes in the basilar circulation can be more disabling than their anterior circulation counterparts. Stenosis exceeding 30% at the origin of the vertebral artery is associated with increased risk of stroke.3 The authors present a case of a female patient with significant peripheral vascular disease who presented with concerns for VBI. The patient was on antiplatelet and anticoagulative medications and a statin at the time of her presentation. Angiography demonstrated bilateral vertebral artery origin stenosis. The left VA was diminutive and arose directly from the arch (Video 1). The right VA demonstrated critical stenosis at its origin. Attempts at endovascular access of the right VA for placement of a balloon-mounted stent were unsuccessful. The patient underwent a transcervical approach for endarterectomy of the VA origin. The VA can be readily accessed using a small supraclavicular incision to isolate the V1 segment of the vessel. The procedure was performed with the patient heparinized and on antiplatelet medications. Alternatives to this strategy include patch grafting in addition to the endarterectomy or use of a short vein graft to bypass the stenosis of the VA beyond the stenotic segment.

Vertebral Artery Access Considerations in Coil Embolization of Small Superior Cerebellar Artery Aneurysm.

BACKGROUND: Coiling of small superior cerebellar artery aneurysms (sSCAAs) is challenging. We aimed to describe anatomic considerations in the vertebral and basilar artery (VA and BA) morphology for decision making in the coiling of sSCAAs. METHODS: Eleven patients with sSCAAs (<5 mm) treated at our institution between April 2015 and February 2022 were included to show our concept of deciding access routes in the coiling of sSCAAs. The access route was decided on the basis of VA characteristics, BA curvature, and aneurysm laterality. Adequate aneurysm occlusion on angiography (Raymond-Roy grading scale I and II), good outcome (modified Rankin Score 0-2) at the last follow-up, and adverse outcomes were evaluated. RESULTS: Simple coiling (n = 2), a balloon-assisted technique (n = 3), and stent-assisted technique (n = 6) were selected. At the last follow-up (median 13.0 months), adequate aneurysm occlusion and good outcome were obtained in all 9 patients (n = 10). Adverse outcomes were not observed. When VA dominance was equal, in the straight BA, the microcatheter insertion into the ipsilateral VA to the aneurysm was favorable to form a "fulcrum" on the contralateral side and obtain microcatheter stability. When an aneurysm was on the concave aspect of the curved BA, microcatheter insertion into the ipsilateral VA was favorable. As for the convex aspect's aneurysm location, the microcatheter insertion into the contralateral VA can be favored. Further, we described the VA origin classification as it relates to ease of access from a transradial approach. CONCLUSIONS: Vertebrobasilar morphology may be important in deciding access routes in the coiling of sSCAAs.

Posterior Inferior Cerebellar Artery Aneurysm Shaped Like a "Calabash Gourd" and Mimicking a Tumor.

Posterior inferior cerebellar artery aneurysms are likely to be fusiform, yet they hardly enlarge to mimic a tumor in the posterior fossa on radiology. They constitute about 3%-4% of all cerebral aneurysms. A 65-year-old woman presented with tremor in her right upper limb for 1 year and intermittent dizziness for 8 months. Interestingly, magnetic resonance imaging revealed 2 unanimously enhanced masses like mother and daughter located in the right cerebellum hemisphere. The lesion was resected via surgery, and histopathology established the diagnosis of an aneurysm. Her tremor and dizziness subsided 3 months after the surgery, and at her 2-year follow-up she was well with no further neurologic deficits.

Neurovascular considerations in patients with Down syndrome and moyamoya syndrome.

In this article, we describe a rare and complex case of moyamoya syndrome in a 7-year-old boy with Down syndrome and atlantoaxial subluxation. The patient presented with an ischemic stroke in the left hemisphere and cervical cord compression with increased cord edema. Diagnostic digital subtraction angiography revealed unique patterns of vascular involvement, with retrograde flow through the anterior spinal artery, ascending cervical artery, occipital artery, and multiple leptomeningeal arteries compensating for bilateral vertebral artery occlusion. This case underscores the underreported phenomenon of upward retrograde flow through the anterior spinal artery in bilateral vertebral artery occlusion. We address the rare manifestation of posterior circulation involvement in moyamoya syndrome, highlighting the importance of considering atlantoaxial instability as a contributing factor, as the absence of atlantoaxial stability is a risk factor for vertebral artery dissection. This study contributes valuable insights into the intricate relationship of moyamoya syndrome, Down syndrome, and atlantoaxial instability, urging clinicians to consider multifaceted approaches in diagnosis and treatment. It also emphasizes the potential significance of the anterior spinal artery as a compensatory pathway in complex vascular scenarios.

Comparative study of left vertebral artery revascularization in patients with and without aberrant left vertebral anatomy.

OBJECTIVE: Left vertebral artery revascularization is indicated in surgery involving zone 2 of the aortic arch and is typically accomplished indirectly via subclavian artery revascularization. For aberrant left vertebral anatomy, direct revascularization is indicated. Our objective was to compare the outcomes of direct vertebral artery revascularization with indirect subclavian artery revascularization for treating aortic arch pathology and to identify predictors of mortality. METHODS: A retrospective cohort study was conducted at a single tertiary hospital, including patients who underwent open or endovascular vertebral artery revascularization from 2005 to 2022. Those who underwent direct vertebral revascularization were compared with those who were indirectly revascularized via subclavian artery revascularization. The outcomes of interest were a composite outcome (any of death, stroke, nerve injury, and thrombosis) and mortality. Univariate logistic regression models were fitted to quantify the strength of differences between the direct and indirect revascularization cohorts. Cox regression was used to identify mortality predictors. RESULTS: Of 143 patients who underwent vertebral artery revascularization, 21 (14.7%) had a vertebral artery originating from the aortic arch. The median length of stay was 10 days (interquartile range, 6-20 days), and demographics were similar between cohorts. The incidence of composite outcome, bypass thrombosis, and hoarseness was significantly higher in the direct group (42.9% vs 18.0%, P = .019; 33.3% vs 0.8%, P < .0001; 57.1% vs 18.0%, P < .001, respectively). The direct group was approximately three times more likely to experience the composite outcome (odds ratio, 3.41; 95% confidence interval, 1.28, 9.08); similarly, this group was approximately six times more likely to have hoarseness (odds ratio, 5.88; 95% confidence interval, 2.21, 15.62). There was no significant difference in mortality rates at 30 days, 1, 3, 5, and 10 years of follow-up. Age, length of hospital stay, and congestive heart failure were identified as predictors of higher mortality. After adjusting for these covariates, the group itself was not an independent predictor of mortality. CONCLUSIONS: Direct vertebral revascularization was associated with higher rates of composite outcome (death, stroke, nerve injury, and thrombosis), bypass thrombosis and hoarseness. Patients with aberrant vertebral anatomy are at higher risks of these complications compared with patients with standard arch anatomy. However, after adjusting for other factors, mortality rates were not significantly different between the groups.

[Surgical Techniques for Microvascular Decompression in Hemifacial Spasm].

This study discusses the key microvascular decompression(MVD)techniques for the treatment of hemifacial spasm(HFS). The author's experience is based on their institution's cases, highlighting three critical techniques. (1)Vertebral artery(VA)repositioning: Repositioning the VA is essential in challenging cases. This article focuses on the relocation of the proximal portion of the VA and the importance of careful dissection. (2)Relocating vessels compressing the peripheral branches of the facial nerve: HFS can result from nerve compression at various locations, including the cisternal portion. This study addressed cisternal compression and considered the nearby nerves. (3)Considering the perforating branches during repositioning, cases may involve complex branching of the perforating arteries. This paper describes an approach that carefully repositions the vessels without damaging the perforating branches. The results from 100 VA-involved cases showed excellent outcomes, with 91.2% of patients experiencing T0(excellent)results. This study emphasized the need to adapt the surgical approach to each unique case to ensure the safety and effectiveness of MVD. This study provides insights into the critical MVD techniques for HFS, emphasizing the importance of continuous experience and knowledge accumulation. These techniques can be learned by other neurosurgeons, thereby expanding the availability of safe and successful MVD procedures for HFS.

Role of a Tortuous Vertebrobasilar Artery and Anchoring Perforators in the Etiology of Hemifacial Spasm.

BACKGROUND: In >70% of patients with hemifacial spasm (HFS), the offending artery is either the anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA), without a tortuous vertebrobasilar artery (VBA). We hypothesized that anchoring perforators around the root exit zone (REZ) of the AICA or PICA might induce vascular deviation and compression. We investigated the occurrence of these perforators from the AICA or PICA and the extent of VBA tortuosity to reveal the pathology of vascular compression. METHODS: This retrospective review included 110 patients after excluding those with vertebral artery (VA) compression alone. The occurrence of perforators was determined according to operative findings within 5 mm of the REZ, and VBA tortuosity was evaluated using MATLAB. We analyzed the association between perforators, VBA tortuosity, and the surgical implications. RESULTS: The occurrence of perforators from the offending AICA or PICA around the REZ was significantly higher in the group without VA compression (Group A) than in the group with VA compression (Group B). VBA tortuosity was significantly lower in Group A. VBA tortuosity was inversely correlated with the presence of AICA or PICA perforators in all 110 patients. Operative results were similar between the groups, although patients with low VBA tortuosity tended to require interposition in decompression procedures. CONCLUSIONS: Anchoring perforators around the REZ play a crucial role in vascular compression for patients with less tortuous VBAs. Moreover, surgeons should be prepared to deal with multiple perforators in a more complicated surgery in cases of less tortuous VBA.

Hidden Bow Hunter's Syndrome Diagnosed Using Dynamic Cerebral Angiography and Successfully Treated with Spinal Surgery: A Case Report and Review of the Literature.

Hidden bow hunter's syndrome (HBHS) is a rare disease in which the vertebral artery (VA) occludes in a neutral position but recanalizes in a particular neck position. We herein report an HBHS case and assess its characteristics through a literature review. A 69-year-old man had repeated posterior-circulation infarcts with right VA occlusion. Cerebral angiography showed that the right VA was recanalized only with neck tilt. Decompression of the VA successfully prevented stroke recurrence. HBHS should be considered in patients with posterior circulation infarction with an occluded VA at its lower vertebral level. Diagnosing this syndrome correctly is important for preventing stroke recurrence.

Bilateral Hunter's bow syndrome: a rare case diagnosed by dynamic digital subtraction angiography.

A 27-year-old female patient suffered from recurrent episodes of dizziness, visual rotation, and intermittent right-hand numbness over one month. Symptoms persisted and were triggered by rotating the head to the right or left for more than 10 seconds. Neurological examination showed that the symptoms were most pronounced when the head was rotated over 45 degrees to the right. Dynamic digital subtraction angiography (dDSA) was performed to confirm the diagnosis. Leftward head rotation caused occlusion of the right vertebral artery(VA) . However, the symptoms were mild, owing to sufficient compensation by the right posterior communicating artery (PCA) . Rightward head rotation exceeding 45 degrees resulted in occlusion of the left VA. The resultant symptoms were pronounced due to inadequate compensation of the left PCA. CT angiographic reconstruction showed bilateral vertebral arteries with tortuous loops of vessels at the level of the C2 vertebrae . CT images showed no cleavage between the left VA and the anterior surface of the left C2 transverse foramen. Conservative treatment was recommended considering the patient's young age and limited severity of her symptoms. Bow Hunter's syndrome is a rare neurovascular disorder characterized by dynamic occlusion of the VAs during head rotation, leading to inadequate blood flow to the posterior cerebral circulation. Bow hunter syndrome, where bilateral dynamic occlusion occurs without a discernible dominant side of the VA, is uncommon. The medical community must acknowledge cervical vertigo as a distinct disorder. dDSA remains the gold standard for its diagnosis.

Vertebral Artery to Middle Cerebral Artery Bypass for Flow Augmentation.

BACKGROUND AND IMPORTANCE: Extracranial-intracranial bypass remains an enduring procedure for a select group of patients suffering from steno-occlusive cerebrovascular disease. Although the superficial temporal artery (STA) to middle cerebral artery (MCA) bypass is most familiar among neurosurgeons, particular circumstances preclude the use of an STA donor. In such cases, alternative revascularization strategies must be pursued. CLINICAL PRESENTATION: A 63-year-old female presented with symptoms of hemodynamic insufficiency and was found to have left common carotid artery occlusion at the origin. She experienced progressive watershed ischemia and pressure-dependent fluctuations in her neurological examination despite maximum medical therapy. The ipsilateral STA was unsuitable for use as a donor vessel. We performed an extracranial vertebral artery (VA) to MCA bypass with a radial artery interposition graft. CONCLUSION: This technical case description and accompanying surgical video review the relevant anatomy and surgical technique for a VA-MCA bypass. The patient was ultimately discharged home at her preoperative neurological baseline with patency of the bypass. The VA can serve as a useful donor vessel for cerebral revascularization procedures in pathologies ranging from malignancies of the head and neck to cerebral aneurysms and cerebrovascular steno-occlusive disease.

The Incidence of Vertebral Artery Injury in Cervical Spine Surgery.

BACKGROUND: Previously reported estimates of vertebral artery injuries (VAIs) during cervical spine surgery relied on self-reported survey studies and retrospective cohorts, which may not be reflective of national averages. The largest study to date reports an incidence of 0.07%; however, significant variation exists between different cervical spine procedures. This study aimed to identify the incidence of VAIs in patients undergoing cervical spine procedures for degenerative pathologies. METHODS: In this retrospective cohort study, a national insurance database was used to access data from the period 2010-2020 of patients who underwent anterior cervical discectomy and fusion, anterior corpectomy, posterior cervical fusion (C3-C7), or C1-C2 posterior fusion for degenerative pathologies. Patients who experienced a VAI were identified, and frequencies for the different procedures were compared. RESULTS: This study included 224,326 patients, and overall incidence of VAIs across all procedures was 0.03%. The highest incidence of VAIs was estimated in C1-C2 posterior fusion (0.12%-1.10%). The number of patients with VAIs after anterior corpectomy, anterior cervical discectomy and fusion, and posterior fusion was 14 (0.06%), 43 (0.02%), and 26 (0.01%), respectively. CONCLUSIONS: This is the largest study to date to our knowledge that provides frequencies of VAIs in patients undergoing cervical spine surgery in the United States. The overall incidence of 0.03% is lower than previously reported estimates, but significant variability exists between procedures, which is an important consideration when counseling patients about risks of surgery.

Bypass Surgery for Vertebral Artery and Posterior Inferior Cerebellar Artery Fusiform Aneurysms: Surgical Technique and Key Lessons.

Fusiform vertebral artery (VA) aneurysms are challenging to treat due to their pathophysiology, morphology, and anatomic location.1,2 Endovascular treatments are considered to be a widely adopted safe option for this pathology.1 Open microsurgical treatment is considered for complex anatomy, important branch involvement, poor collateral flow, or failed endovascular therapy.3-7 This report aims to show the flow-replacement strategy and bypass technique for a VA aneurysm with complex anatomy and branch involvement. A 24-year-old man presented to our clinic with a bilateral fusiform VA aneurysm discovered during workup of progressive headaches. Further investigation revealed that the left-side aneurysm was mostly thrombosed and the posterior inferior cerebellar artery arose from the aneurysm dome with a fusiform enlargement within a few millimeters from the branching point. After evaluating all management options, the patient decided on surgical treatment of the left VA aneurysm. We performed an occipital artery to posterior inferior cerebellar artery end-to-side anastomosis distal to the fusiform enlargement, followed by trapping of the aneurysm and dome resection (Video 1). Antegrade flow to the distal VA was reestablished using a radial artery interposition graft, thus preventing any flow alterations that may cause growth or rupture of the contralateral aneurysm caused by increased hemodynamic stress if the ipsilateral VA flow is not preserved.8 After in-hospital physical rehabilitation, the patient was discharged with a modified Rankin Scale score of 1. The contralateral aneurysm is managed with serial imaging and treatment will ensue if there is clinical-radiologic evolution. The patient consented to the procedure and publication of his image.

Efficacy and predicting factors of multimodal treatment for ruptured intracranial vertebral artery dissecting aneurysms.

We aimed to investigate the efficacy of our multimodal strategies and propose a treatment algorithm for ruptured vertebral artery dissecting aneurysms (VADAs). This study included 41 patients treated at a single institution between 2015 and 2022. The treatment modalities were justified based on the collateral circulation and aneurysm location related to the posterior inferior cerebellar artery (PICA). Treatment outcomes and complications of each treatment group were analyzed. The association between the collateral blood flow and the postoperative vertebrobasilar ischemia (VBI) was also investigated. There were 17 post-PICA, 10 PICA-involved, 7 pre-PICA, and 7 non-PICA types. Reconstruction techniques included flow diversion devices (n = 11) and stent-assisted coiling (n = 3). Deconstruction techniques included coil trapping (n=17) and microsurgical parent artery occlusion with (n = 8) or without PICA revascularization (n = 2). Five (18.5%) of the deconstruction group had postoperative VBI. Overall favorable outcomes in both groups were observed in 70.7% of patients with a mean follow-up time of 21.5 months. Poor World Federation of Neurosurgical Societies grade (IV-V) was identified as a predictor of unfavorable outcomes (p = 0.003). In addition, the VA4/BA4 ratio > 0.22, the presence of collateral blood flow from the posterior communicating artery (PcomA), and a contralateral VA diameter > 2.5 mm were associated with a lower risk of postoperative VBI. In summary, the proposed strategic treatment in this study is pragmatic, yielding satisfactory results where a deconstructive technique should be used with caution, particularly when there is a flow mismatch or the absence of collateral PcomA in the vertebrobasilar circulation.