In human anatomy, the vertebral artery, in its passage from the subclavian artery to the foramen magnum of the skull, enters the transverse foramina of the vertebral column generally at the level of the 6th cervical vertebra. Nevertheless, even though avoided by the vertebral artery, also the 7th cervical vertebra (C7) contains a transverse foramen. The content of this transverse foramen in C7 has been unclear, with different descriptions found in textbooks and in original literature. Here, we have revisited the content of the transverse foramen in C7 by macroscopic dissection of 32 human specimens. We found that the 7th transverse foramen never contained the vertebral artery. Instead, it enclosed in 35% of the cases both vertebral vein and vertebral nerve, in 20% of the cases only the vertebral nerve, in 11% of the cases only the vertebral vein, and in 34% of the cases it contained no macroscopically visible neurovascular structure at all but only adipose connective tissue.

OBJECTIVE: The aim of our study is to report a case of a large fenestrated vertebral artery (FVA) and bilateral duplication of the superior cerebellar artery (SCA) incidentally diagnosed using Computed Tomography Angiography (CTA) and Digital Subtraction Angiography (DSA).
METHODS: A 63-year-old female patient presenting to the neurology clinic with complaints of dizziness and balance disorder. CTA and DSA revealed a large FVA involving the V3 and V4 segments. Additionally, we observed bilateral duplicated SCAs originating from the distal basilar artery.
CONCLUSIONS: FVA is a rare anomaly resulting from fusion failure during the embryological period, with a reported incidence of 0.1%. FVA is often (70%) detected in the extracranial region, but it can also occur intracranially at a frequency of approximately 30%. Although various nomenclatures are used in the literature, we identified only two reports of a single fenestration encompassing the V3 and V4 segments, i.e., involving both the extracranial and intracranial regions. While duplication of the SCA is relatively common, bilateral duplication of SCA occurs at a rate of 0.9-5%.
CONCLUSIONS: This case report describes an unusual case of VA fenestration involving both extracranial and intracranial segments, along with bilateral duplication of the SCAs. While rare, these findings highlight the importance of recognizing such vascular anomalies, which could be relevant for planning surgical or endovascular procedures in the posterior circulation.

OBJECTIVE: To propose a screw algorithm and investigate the anatomical feasibilities and clinical outcomes of five distinct fixation methods for C2-3 fused vertebra with high-ridding vertebral arteries (VA) (HRVA) when the C2 pedicle screw placement is unfeasible.
METHODS: Thirty surgical patients with congenital C2-3 fusion, HRVA, and atlantoaxial dislocation (AAD) were included. We designed a algorithm for alternative screw implantation into C2-3 fused vertebrae, including C2 pedicle screw with in-out-in (passing VA groove) technique (in-out-in screw), subfacetal screw, translaminar screw, lateral mass screw, C3 pedicle screw. VA diameter and position, C2 and C3 pedicles, superior facets, fused lamina, and fused lateral mass dimensions were evaluated for screw implantation indication. Implant failure, reduction loss, implant placement accuracy were investigated by computed tomography.
RESULTS: A total of 5 VAs were identified as distant VAs; a total of 2 VAs were categorized as occlusive VAs. Sufficient dimension of lateral mass and lamina provided the broadest indications for screw implantation, while the distant or occlusive VA provided the most limited indications for in-out-in screw. The indications of five alternative methods ranged from narrowest to widest as follows: in-out-in screw, C3 pedicle screw, subfacetal screw, translaminar screw, lateral mass screw. The translaminar screws and the lateral mass screws increased the probability of implant failure. All patients who received in-out-in screws, C3 pedicle screws, and subfacetal screws achieved fusion. The accuracy ranged from lowest to highest as follows: C3 pedicle screw, lateral mass screw, in-out-in screw, subfacetal screw, translaminar screw. No translaminar screws deviated.
CONCLUSIONS: The algorithm proved to be a valuable tool for screw selection in cases of C2-3 fused vertebrae with HRVAs. The subfacetal screw, boasting broad indications, a high fusion rate, and exceptional accuracy, stood as the primary preferred alternative.

UNASSIGNED: The dominant vertebral artery (VA) approach is primarily considered in mechanical thrombectomy (MT) for acute occlusion of the vertebrobasilar (VB) artery. As accessing the dominant artery is sometimes difficult, we present our experience treating acute VB stroke via a nondominant VA approach through a comparison with the dominant VA approach.
UNASSIGNED: Among 2,785 patients diagnosed with hyperacute ischemic stroke between January 2014 and December 2022, 50 patients with VB ischemic stroke underwent recanalization therapy through either dominant, nondominant, or bilateral VA approach. We evaluated patient characteristics and clinical course, highlighting the pros and cons of the access routes.
UNASSIGNED: The patients with hyperacute VB ischemic stroke were predominantly male (72%), with a mean age of 68.12 years and an initial National Institutes of Health Stroke Scale (NIHSS) score mean of 17.1. Large-artery atherosclerosis (LAA, 48%) and cardio-embolism (CE, 36%) were the main etiologic factors in the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. After thrombectomy, 45 (90%) cases had final modified thrombolysis in cerebral infarction (mTICI) score of 2b or higher. In summary, 41 patients were treated through the dominant VA, and 8 patients underwent the nondominant VA approach. However, there was no statistically significant difference in functional outcome or mortality between the two approaches.
UNASSIGNED: In MT for VB occlusions, nondominant VA approach may be an option in situations when the vessel is accessible, stable, or less risky, as recanalization can be achieved without rescue balloon angioplasty and/or stenting.

UNASSIGNED: Anterior cervical discectomy and fusion (ACDF) is a common cervical procedure with more than 137,000 cases in the United States (U.S.) each year. Historically, ACDF has been a relatively safe procedure despite encountering vital anatomical structures that can risk serious complications. One particularly dangerous sequela of ACDF is the risk of lacerating the vertebral artery (VA). While VA injuries are rare (0.5% of cases), it is crucial for surgeons to prevent this potentially deadly complication with thorough knowledge of VA anatomy. The VA is commonly protected within the transverse foreman; however, anomalies can exist with the artery potentially being found more medial or proximal within the surgical site than expected. The purpose of this article is to report an anomaly found in a cadaveric specimen, where the VA courses within 2 mm of an ACDF plate.
UNASSIGNED: A 66-year-old male with a past medical history of coronary artery disease passed away due to complications of a myocardial infarction. During cadaveric dissection, it was discovered that the donor had undergone a previous 3-level (C4-C7) ACDF procedure for an unknown reason. Under further examination, the left VA was observed to take an anomalous medially tracking course before eventually entering the transverse foramina of C5. Left anterior tubercles were absent at the level of C5 and C6 with prominent osteophytes found on the anterior tubercles/transverse foramina of the contralateral side.
UNASSIGNED: There are no studies published on the anatomy of VA variants and their implications on ACDF procedures. ACDF was found to have complication rates in 13.2% of cases. VA variants are observed in up to 20% of the U.S. population and VA injury in ACDF procedures has a rate near 0.5%. With anatomic variations leading to a higher risk of injury, surgeons are required to take further precautionary steps before operating including ordering computed tomography angiography or magnetic resonance angiography films. Understanding the detailed anatomy of the VA and its variants is critical. Using the perspectives of orthopedic spine surgeons, this study supplements the literature on potential VA anomalies encountered in ACDF procedures.

This case report describes a 40-year-old male who presented with chronic neck pain radiating to the left upper limb, associated with weakness and numbness. He also had symptoms of vertebrobasilar insufficiency. Imaging revealed an intraneural foramen vertebral artery (VA) loop compressing the C3 nerve root. Conservative management was ineffective, prompting surgical decompression via a left C2-C3 facetectomy and foraminotomy. The patient experienced immediate pain relief and gradual improvement in weakness, with complete resolution of symptoms at the six-month follow-up. This case highlights the potential for VA loops to cause radiculopathy and the successful use of surgical decompression for treatment.

Previous studies have reported various anatomical differences in the cerebral artery between healthy subjects and patients with posterior circulation cerebral infarction. In particular, basilar artery angulation has been associated with posterior circulation cerebral infarction. We compared anatomical variations and the degree of anterior and lateral vertebrobasilar artery angulation and deviation to compare the incidence of cerebral infarction of healthy subjects and patients with posterior circulation cerebral infarction. We compared basilar artery anatomy using brain magnetic resonance angiography in 97 patients who underwent brain magnetic resonance angiography during health checkups at our hospital and in 92 patients diagnosed with posterior circulation cerebral infarction between 2012 and 2022. Anatomical variations, including fetal-type posterior cerebral artery, hypoplastic P1 segment, vertebrobasilar dolichoectasia, and dominant vertebral artery, as well as the degree of anterior and lateral deviation and angulation, were evaluated. Correlations between these variations and the occurrence of cerebral infarction were analyzed. The prevalence of hypoplastic P1 was significantly differences in patients with posterior circulation cerebral infarction (odds ratio: 5.655). Furthermore, patients with posterior circulation cerebral infarction exhibited more acute anterior and lateral angulation, as well as lateral deviation. Hypoplastic P1 and more acute anterior or lateral angulation of the vertebrobasilar artery are associated with increased frequency of cerebral infarction.

BACKGROUND: Spinal cord infarction is an uncommon nervous system disorder. We present a case of high cervical cord infarction caused by stenting of the origin of the left vertebral artery (VA). The incidence of spinal cord infarction is minimal, and it must be distinguished from a number of other disorders. The diagnosis is primarily based on imaging, clinical symptoms, and history. Currently, there is no focused treatment for spinal cord infarction. Thrombolysis, high-dose glucocorticoid shocks, tube dilatation to promote circulation, and nutritional neurotropic medicines given early in the course of the disease can all help to slow the disease\'s progression. There is no agreement on the etiology, diagnosis, or therapy options for these people.
METHODS: On October 7, 2023, an 81-year-old man was admitted to the hospital primarily for recurrent chest tightness and pain that had persisted for more than 2 years and 1 month. Cerebral angiography upon admission revealed significant blockage of the right VA and stenosis of the left vertebral arterial origin. Six days following admission, a drug-eluting stenting procedure was carried out under local anesthesia to open the left VA origin via the femoral artery. Following the procedure, the patient experienced a progressive loss of muscle strength in all 4 limbs and paraplegia below the cervical 3 spinal cord. One week following the procedure, the patient was released from the hospital. After the procedure, the patient was released 1 week later. After the procedure, the patient\'s symptoms persisted for a month.
CONCLUSIONS: High awareness for high cervical cord infarction is required when neck discomfort and limb weakness with progressive progression arises after surgery. Complications of high cervical cord infarction following stenting for stenosis of VA origin are uncommon in clinical settings. Patients\' prognoses can be improved by prompt diagnosis and care.

METHODS: A descriptive, quantitative cross-sectional study of the atlantic part (V3) of the vertebral artery (VA).
OBJECTIVE: This study aimed to bridge the research gap in the morphometry of the V3 segment of the VA in the South Indian population.
BACKGROUND: The microsurgical anatomy of this segment of the VA has been explored in various populations, and a thorough understanding of the anatomy and course of the VA, particularly the V3 segment, is essential to prevent iatrogenic complications. Several computed tomography studies but a few cadaveric studies have explored the V3 segment of the VA in the South Indian population.
METHODS: This study examined 40 VAs from 20 embalmed cadavers that were obtained from the voluntary donation program, and Institutional Ethical Clearance was obtained before the study. The length, diameter, and angle of the vertical, horizontal, and exit parts of the V3 segment of the VA were documented after its exposure.
RESULTS: The mean lengths of the right and left VAs on each part were nearly similar, except for the mean length of the horizontal part (right: 38.937 mm, left: 40.237 mm) and total length of the V3 segment (right: 66.870 mm, left: 70.350 mm).
CONCLUSIONS: These morphometric parameters are essential to spine surgeons who intend to operate on a small part (vertical, horizontal, or exit part) of the V3 segment of the VA. The mean values of the parameters obtained in this study give average measurements or safe limits to surgeons for safe surgical procedures such as the occipital condyle screw technique and C1 laminectomy.

OBJECTIVE: Posterior circulation cerebral bypasses often show higher risks and lower patency. Only few reports discussed occipital artery (OA)-vertebral artery (VA) bypasses. We present our illustrative cases to address current gaps in the literature on OA-VA bypass.
METHODS: A single-center retrospective review was conducted to include all institutional cases of OA-VA bypass, discussing the technique and outcomes.
RESULTS: Four institutional cases undergoing a total of 5 bypasses were evaluated, including 3 males and 1 female, with median age of 65 years (range, 62-73). All patients had vertebrobasilar insufficiency (VBI) with recurrent strokes/TIAs due to intracranial atherosclerosis, leading to unilateral VA stenosis with contralateral occlusion (1, 25%), bilateral VA stenosis (1, 25%) or occlusion (1, 25%). Medical management included aspirin for all cases (100%), with clopidogrel in 3 (75%). Surgery was performed through a far lateral approach, connecting the OA to the VA-3 segment, with no inter-positional graft. One patient underwent contralateral OA-VA bypass 6 months after the prior surgery due to worsening of the contralateral VA stenosis. Bypass patency was confirmed in all cases with post-operative angiography. All patients had clinical improvement, with one case of wound dehiscence managed conservatively. All patients were alive at last follow-up (median 7.0 months; range: 1.5-18).
CONCLUSIONS: OA-VA bypass is a challenging yet effective strategy in selected patients with VBI. Current literature lacks unique definitions of surgical indications and techniques, which we addressed in our series. Surgical education should focus on expanding the microsurgery anatomy knowledge.