V3 Segment Of Vertebral Artery Research Articles

Analysis of the clinical characteristics of V4 segment steal blood in the vertebral artery

Objective: To explore the clinical characteristics of unilateral vertebral artery V4 segment occlusive lesions (severe stenosis or occlusion), where the contralateral vertebral artery can be compensated through blood flow and reverse supply to the posterior inferior cerebellarartery (PICA). Methods: This study is a retrospective case series of 66 patients with V4 segment occlusive lesions of unilateral vertebral artery diagnosed and treated from June 2020 to October 2022. Patient data were retrospectively collected, and their hemodynamic characteristics and imaging data were analyzed. Results: Of the 66 cases, 11 patients (16.7%) with V4 segment occlusive disease showed the blood flow of the vertebral artery on the opposite side of the lesion on the digital subtraction angiography (DSA), which can be reverse stolen to the posterior inferior cerebellar artery of the diseased side through the confluence point of the vertebrobasilar artery through the distal end of the ipsilateral vertebral artery V4. Owing to the lack of literature on this pathway and based on the characteristics of previous definitions of subclavian artery steal and carotid artery steal, we referred to this pathway as the vertebral artery V4 segment steal. In 6 patients (9.1%), transcranial Doppler ultrasound (TCD) and transcranial color Doppler ultrasound (TCCD) showed that the blood flow signal was not detected at the proximal end of the V4 segment of the affected side, rather the blood flow direction was reversed at the distal end of the V4 segment, resulting in compensatory acceleration of the blood flow velocity of the V4 segment of the contralateral vertebral artery. Conclusion: "V4 segment steal of vertebral artery" is a very rare route of vertebral artery steal. When V4 segment of the vertebral artery is occluded, clinicians should pay attention to observe the blood supply of PICA and whether there is such a steal route, to better evaluate the blood flow compensation and prognosis of patients.

Cluster of variations involving vertebral, renal, and obturator arteries in a single human body- A cadaveric case report

We describe a unique triad of arterial variations that include vertebral, renal, and obturator arteries in a single cadaver. A combination of arterial variations was observed in a 60-year male; formalin embalmed cadaver during the routine dissection while teaching undergraduate students. The origin, course, branching pattern, and termination of the vertebral, renal, and obturator arterial systems were noted, along with the vessels' diameter close to their origin. The following variations were observed: a) Hypoplastic V4 segment of the right vertebral artery; Right Posterior Inferior Cerebellar artery had a relatively proximal origin from the V4 segment of vertebral artery and coursed in an inverted ‘U’ shaped manner cranially, which resembled duplicated V4 segment of the right vertebral artery, b) Right accessory renal artery originated from abdominal aorta distal to the right renal artery and the right gonadal artery originated from the right accessory renal artery, c) Right obturator artery originated from the posterior division of the right internal iliac artery, and the left obturator artery originated from the trunk of the left external iliac artery. Such a combination of variations in the anatomy of vertebral, renal, and obturator arteries was not reported previously. This case report will interest neurosurgeons and radiologists because of the possibility of concomitant arterial variations.

Abstract 094: Sudden Onset Dysphagia: A Symptom To Be Aware of During Code Strokes

Introduction Lateral medullary infarction (LMI) can present with dysphagia, dysphonia, dysarthria, vertigo, nausea, skew deviation, and ipsipulsion. Patients may also exhibit sensory loss and ipsilateral Horner’s syndrome. LMS often develops because of an acute infarct from the vertebral arteries or posterior inferior cerebellar arteries (PICA). The most common mechanism of stroke usually is atherothrombosis, followed by cardioembolic, dissection and embolic source of undetermined source (ESUS). While dysphagia often accompanies the constellation of LMS symptoms, it is rarely the first symptom and has only been reported in a few cases in the literature. In this report we describe the case of a man in his 40s with acute onset dysphagia as the presenting finding ahead of an LMS diagnosis. Methods The patient was identified in routine clinical practice. Results A man in his 40s with medical history of HTN, type 2 DM and polycystic kidney disease, presented with sudden‐onset dysphagia which started while he was drinking alcohol. Later he noticed that he was unable to keep his balance. His National Health Institute Stroke Scale was 4. Neurologic exam was pertinent for left‐sided miosis, ptosis, and dysmetria. Pinprick and temperature sensation were decreased on the right arm and leg. Facial sensation to light touch was diminished on the left. Brain MRI showed an acute infarct in the left lateral medulla (Figure A). CTA showed calcified atherosclerosis of the V4 segment of left vertebral artery (Figure B). Mechanism of ischemic stroke was artery to artery thromboembolism from the left V4 segment of vertebral artery. For secondary prevention, dual antiplatelet therapy, high intensity statin, and optimization of his risk factors were initiated. Conclusion This case report demonstrates that dysphagia can be the initial symptom of an acute ischemic stroke. Diagnosis and recognition of an atypical presentation of lateral medullary syndrome can pose a particular challenge especially in this era of “time is brain” but is of the utmost importance to facilitate good outcomes. Patients presenting with dysphagia who have risk factors for stroke and no other obvious etiology for their symptoms should be worked up for possible cerebrovascular etiology.

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.

Is Revascularization of V1 Segment of Vertebral Artery Combined with Ipsilateral Carotid Endarterectomy Safe?

The recommendation of the European Society for Vascular Surgery (ESVS) is that vertebral revascularization combined with ipsilateral CEA (carotid endarterectomy) should not be performed in the same operation. ESVS believes that vertebral revascularization combined with ipsilateral CEA increases perioperative death/stroke rates. In our opinion, revascularization of the first segment of vertebral artery (V1) combined with ipsilateral CEA is safe compared to vertebral V1 revascularization in the perioperative period. The purpose of this study is to prove that revascularization of V1 segment of vertebral artery combined with ipsilateral CEA is secure in the perioperative period. We describe our experience with homochronous revascularization of V1 segment of vertebral artery with ipsilateral CEA (group B) and simple revascularization of V1 segment of vertebral artery (group A) in 48 consecutive patients during a 5-year period. O.Y. (Ouyang) incisions were used in both groups. We compare the results of the 2 procedures with aspects of mortality, stroke, morbidity, incident rates of complications, and so on. There was no significant difference between patients in group A and group B in terms of red blood cell reduction, postoperative ventilator using time, postoperative drainage volume, postoperative drainage days, postoperative hospitalize duration, and incident rates of postoperative complications. The postoperative complications include death, stroke, Horner syndrome, vocal paralysis, hypoglossal nerve paralysis, wound hematomas, and lymphatic leakage. Revascularization of vertebral artery combined with ipsilateral CEA should be divided into revascularization of V1 segment of vertebral artery combined with ipsilateral CEA and revascularization of V3 segment of vertebral artery with ipsilateral CEA. Revascularization of V1 segment of vertebral artery combined with ipsilateral CEA is safe; it can be performed for suitable patients who are fit for indications. O.Y. incisions can fully expose the target blood vessels and simplify the procedures without transecting the sternocleidomastoid muscles in operations.

Far lateral approach without occipital condylar resection for intradural ventral/ventrolateral foramen magnum tumors and aneurysms of V4 segment of vertebral artery: Review of surgical results

BackgroundControversies exist regarding the need and extent of condylar resection for safe surgical management of intradural ventral/ventrolateral foramen magnum (VFM) tumors and aneurysms of V4 segment of vertebral artery (VA) by far lateral approach. This retrospective study was conducted to evaluate the results of basic far lateral approach(retrocondylar approach) without upfront occipital condylar resection. Methods and ResultsTwenty one patients underwent surgery via far lateral approach for intradural VFM tumors and aneurysms of V4 segment of VA at Sri Sathya Sai Institute of Higher Medical Sciences during 9 years(2008–2016) study period. Eight patients had VA aneurysms and 13 patients had intradural VFM tumors. After basic far lateral approach(retrocondylar approach), dura was opened and checked if the exposure was adequate for safe surgery. Retrocondylar approach provided adequate exposure for all these lesions and resection of occipital condyle/jugular tubercle was not required in any of these cases. Skeletonization or transposition of VA was not done in any of these cases. Gross total resection of the tumor could be done in 9 patients(9/13–69.2 %) and near total excision (>95 %) in 4 patients (4/13–30.8 %). Seven of the 8 VA aneurysms were successfully clipped. Outcome at a final follow up of 3 months or more was good(mRS<2) in 19 patients(19/21–90.5 %) and poor in 2 patients. Complications included lower cranial nerve deficits [transient-2/21(9.5 %), persisting-2/21(9.5 %)], motor deficits(2/21−9.5%), seventh nerve paresis(1/21−4.8%), sixth nerve paresis(2/21−9.5%) and pseudomeningocele(1/21−4.8%). ConclusionBasic far lateral (retrocondylar) approach provides excellent exposure for majority of VFM tumors and aneurysms of V4 segment of VA. Condylar resection(transcondylar approach), drilling of jugular tubercle (transtubercular approach), skeletonization/transposition of VA might not be required for safe surgical management of majority of these lesions.

Feasibility and Safety of Paclitaxel-Coated Balloon Angioplasty for the Treatment of Intracranial Symptomatic In-Stent Restenosis.

Objective: Symptomatic in-stent restenosis (sISR) is the major cause of medium- or long-term cerebral infarctions in patients who underwent percutaneous transluminal angioplasty and stenting for severe intracranial atherosclerotic stenosis. This study aims to evaluate the feasibility and safety of paclitaxel-coated balloon (PCB) angioplasty for the treatment of intracranial sISR.Methods: We report 11 cases of PCB angioplasty for intracranial sISR. Lesion locations and number were as follows: intracranial internal carotid artery (n = 4), M1 segment of middle cerebral artery (MCA) (n = 1), V4 segment of vertebral artery (n = 6). The technical success rate, periprocedural complications, and short-term outcome were retrospectively analyzed.Results: All procedures were successfully performed without periprocedural complication. Asymptomatic vessel dissection after PCB inflation occurred in one case. Postprocedural diffusion-weighted imaging (DWI) showed new asymptomatic ipsilateral infarction in one case. All 11 cases did not experience ipsilateral stroke or death within 30 days or ischemic stroke in the territory of the target artery between 31 and 90 days after procedure.Conclusion: This preliminary study indicates that PCB angioplasty is feasible and safe for the treatment of intracranial sISR. Further studies are needed to clarify its efficiency and long-term outcome.

Vertebral-carotid bypass for common carotid artery occlusion

One of the treatment options for long segment common carotid artery (CCA) occlusion is bypass surgery with different combinations of donors and receipts. Using vertebral artery (VA) as the donor for CCA occlusion was uncommonly reported. The reported cases were using jump graft to connect V3 segment of VA to either CCA or ICA. We describe our patient using V2 segment as the donor for VA-CCA bypass as treatment for CCA occlusion. Our patient was a 51 years old gentleman with Marfan syndrome and had multiple operations that included total arch replacement. He presented with sudden onset of spontaneous right frontal subarachnoid haemorrhage and repeated episodes of TIA with left upper limb numbness. CTA showed occluded right CCA and anastomosis between branches from subclavian artery and occipital artery. CT perfusion showed hypoperfusion of right hemisphere. To avoid damaging the anastomosis at subclavian artery and occipital artery, we decided for V2-RAG (radial artery graft)-CCA bypass. It was done by exposing the V2 segment at C4/5 level, performing end-to-side anastomoses at V2-RAG and RAG-CCA junctions where the RAG was underneath the internal jugular vein. Patient had no new deficits after surgery and no more TIAs. CTA performed one week after surgery showed patent RAG. In conclusion, using V2 for VA-CCA bypass is technically feasible and may have theoretical advantages over using V3. V2-CCA bypass is an option for CCA occlusion in very selected patients.

Bow Hunter's Syndrome: Complete Microsurgical Decompression of Vertebral Artery by Far Lateral Retrocondylar Approach: 3-Dimensional Operative Video.

This 50-yr-old man had a 15-yr history of presyncopal episodes that were precipitated by turning his head to the right, and had worsened recently. Cerebral angiogram demonstrated complete cessation of anterograde flow in left vertebral artery (VA) at the level of the C1 sulcus arteriosus while turning head to right, indicating dynamic compression at the C1 level. Patient underwent left extreme lateral retrocondylar approach, partial C1 laminectomy and opening of the C1 foramen with complete microsurgical decompression of the VA. After skin incision, meticulous muscle dissection was performed and superior and inferior oblique muscles were disconnected from the tubercle of C1. The VA was exposed, and three areas of constriction were visible, first at the atlanto-occipital membrane laterally; second, located more medially as the artery curved around the occipital condyle to enter the posterior fossa; and third, located anterior to C2 nerve root. The artery was dissected from all the surrounding tissues, preserving the C2 nerve root, and the Cl foramen was opened completely. The Cl lamina was also partially resected and grooved to allow free placement of the VA. The VA was also decompressed near the C2 foramen. Postoperative computed tomography angiogram of the head and neck showed complete decompression of VA. The patient had no episodes of presyncope or dizziness while turning head to right and his mRs was 0 at 8 mo follow up. This 3D video shows the technical nuances of decompression of V3 segment of VA in bow hunters's syndrome. Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

Surgicoanatomical aspect in vascular variations of the V3 segment of vertebral artery as a risk factor for C1 instrumentation

ObjectAwareness of vascular anomalies in V3 segment of vertebral artery (VA) is crucial to avoid iatrogenic injuries during surgical procedure. This study aimed to analyze the incidence of V3 segment vascular variations and demonstrate the importance of deciding the surgical strategy for C1 screw placement. MethodsPrevalence of vascular variations and morphometric measurements of the VA in the region of the craniocervical junction in 200 cases based on three-dimensional computed tomographic angiography (3D-CTA) scans were studied. ResultsThe VA has a variable course through C2 before it passes above its groove on the posterior arch of C1. Following the vascular variations of V3 segments of VA were persistent including first intersegmental artery (FIA), fenestration (FEN) of the VA, high-riding (HRVA and the posterior inferior cerebellar artery (PICA) branch originating from the C1/2 part of VA. HRVA was observed in 10.1% of patients, FIA in 1.8%, FEN in 1.3%, and PICA in 1.3%. One hundred and twenty-three (24.1%) patients were identified to have HRVA, 6% present on both sides. ConclusionThe VA with FIA and FEN were rare in this study as many as a 10% the VA present over the starting point for C1 lateral screw. With respect to the vascular anatomy of V3 and more frequent left-sided VA dominancy, standard screw insertion should be started from the right side. Routine preoperative 3D-CTA evaluation is mandatory to prevent the VA injury when C1-C2 instrumentation is planned.

Assessment of the Accuracy and Errors of Head-Up Display by an Optical Neuronavigation System in Brain Tumor Surgery

A head-up display (HUD) in which navigational information is projected into the microscope view may enable surgeons to perform operations more efficiently. Projecting depictions of both tumor and important intracranial structures on the HUD may facilitate safe surgery. To investigate accuracy and errors regarding important intracranial structures, errors due to brain shifts, and preservation rates for important intracranial structures. A total of 184 surgeries in 172 patients were performed using this operation system. Postoperatively, we determined accuracy and errors for actual structures and virtual reality on the HUD and performed statistical analyses. Preresection accuracy for important intracranial structures was highest for the internal carotid artery (ICA; 90.4%) and lowest for the posterior inferior cerebellar artery (53.6%). Differences between pre- and postresection accuracy were greatest, in descending order, for the cortical vein ( P < .0001), V4 segment of vertebral artery ( P < .0001), and anterior inferior cerebellar artery ( P = .00780), whereas differences between pre- and postresection errors were smallest for the cranial nerve V ( P = .500), middle cerebral artery ( P = .0313), and ICA ( P = .0313). Cases of poor preresection accuracy and large differences in pre- to postresection accuracy were seen in the prone position. A reliable surgical resection rate was achieved using the HUD, and reliable preservation of important intracranial structures was also possible. Accuracy was concluded to be within an acceptable range.

Correlation between ponticulus of atlas and abnormal morphology of V3 segment of vertebral artery using multi-slice spiral CT angiography

Objective To explore the correlation between ponticulus of atlas and abnormal morphology of V3 segment of vertebral artery. Methods All patients included in this study were underwent CTA and 3D reconstruction examination of intracranial ponticulus and cervical in our workstation, as well as the site, shape of petals and its relationship with vertebral artery was observed. The diameter, shape and trail of vertebral V3 segment were measured and analyzed. The results were analyzed by χ2 test. Results A total of 195 sides (157 cases) ponticulus were detected in 613 cases (1 226 sides), the abnormal morphology of V3 segment of vertebral artery were 103 sides and combined with ponticulus 69 sides among them, including (according to side): the collectivity was 8.4% (103/1 226), combination ponticulus was 35.4% (69/195), uncombination ponticulus was 3.3% (34/1 031), and the risk with ponticulus was increased compared with no ponticulus, and showed statistical significance by Chi-square test (χ2=215.679, P=0.001). The difference of abnormality of vertebral artery was performanced in number, site and shape of ponticulus, we found that the ponticulus composite was 57.1% (12/21) and higher than ponticulus simple 32.8%(57/174) (χ2=4.873, P= 0.027), the ponticulus borderl was 68.8% (11/16) which was also higher than ponticulus posticus (27.2%) and ponticulus lateralis (36.4%) in the ponticulus simple (χ2=11.357, P=0.030), the sharp ones (64.2%) were higher than the blunt (14.6%)in the tip of bony processes of the incomplete type ponticulus (χ2=26.813, P=0.001 ),the smaller ones were higher than the larger in the distance of the gap between the two tips of bony processes in the incomplete type ponticulus (χ2=9.212, P=0.010), and the smallerones (87.5%) were also higher than the larger (28.6%)in the diameter of the hole of complete type ponticulus (χ2=18.193, P=0.001), all of the above ones showed statistical significance among all groups by Chi-square test (P<0.05). Conclusions Ponticulus of atlas can significantly increase the risk of abnormal morphology of V3 segment of vertebral artery, and the differences of abnormality of vertebral artery were performed in number, site and shape of ponticulus, which included the ponticulus composite, ponticulus borderland, the shape tip of bony processes, the moderate distance between the two lip of bony processes, and the smaller diameter of complete type Ponticulus. Key words: Atlanto-occipital joint; Vertebral artery; Angiography; Tomography, spiral computed

The computed tomography angiography study of the spatial relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery

Background ContextTo our knowledge, there is no study that has systematically analyzed the relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery (VA V3 segment). PurposeTo study the relationship between C1 transpedicular screw trajectory and VA V3 segment. Study DesignA morphologic computed tomography angiography (CTA) analysis of the spatial relationship between C1 transpedicular screw trajectory and VA V3 segment. MethodsMeasurements were made on a workstation by using CTA data of 62 patients. Firstly, parameters related to the relationship between C1 vertebral artery groove (VAG) and vertebral artery (VA) were measured: (A) the shortest distance between the posterosuperior aspect of C1 posterior arch and VA; (B) distance between the outer aspect of VAG and VA; (C) distance between midpoint of VAG and VA; and (D) distance between the inner aspect of the VAG and VA. Then, the central axis of trajectory perpendicular to the coronal plane (axis P) and the central axis of trajectory with a medial inclination (axis M) were designed for the basis of measurements. Parameters related to the relationship between axis P/M and VA V3 segment were measured respectively: (E, E′), distance between insertion point and anterior aspect of VA along axis P/M; (F, F′), the shortest distance between axis P/M and the outer cortex of C1 transverse foramen; and (G, G′), the narrowest width of C1 internal medullary canal along axis P/M. ResultA, B, C, and D were 1.7±1.0 mm, 1.6±0.9 mm, 1.5±0.7 mm, 2.3±1.1 mm, respectively. E, E′ were 5.5±1.7 mm and 4.1±2.3 mm. F, F′ were 1.9±0.7 mm and 2.9±0.7 mm. G, G′ were 3.7±1.4 mm and 4.8±1.2 mm. There was a little interspace between atlas VAG and VA, which was mainly filled with venous plexus. ConclusionsThere is a close relationship between C1 transpedicular screw trajectory and VA V3 segment. Trajectory with medial inclination technique is suggested especially for female patients.

An Unusual Posttraumatic Pseudoaneurysm of Intracranial Segment (V4) of the Vertebral Artery

Traumatic pseudoaneurysm of the vertebral artery is an uncommon and one of the most difficult lesions to treat. Posttraumatic vertebral artery pseudoaneurysm is located mostly extracranially, and its intracranial occurrence is exceedingly rare. We report a case of an 18-year-old man who underwent successful treatment of posttraumatic intracranial pseudoaneurysm of V4 segment of the vertebral artery by endovascular embolization. The patient who sustained trauma in a road accident presented with the complaints of headache, giddiness, and vomiting for the last 13 days. On admission, he was conscious but drowsy with no focal neurologic deficit. CT scan of the brain was suggestive of no significant intracranial abnormality. As the patient had headache, vomiting, and drowsiness, the CT was unable to explain his clinical picture, so CT angiography was performed to exclude vascular abnormality. CT angiography of the brain was suggestive of left vertebral artery aneurysm arising from V4 segment of the left vertebral artery. DSA showed a large pseudoaneurysm arising from left V4 segment of the vertebral artery near origin of PICA. Because of its difficult location, surgical treatment is less preferable as compared with endovascular treatment. The patient underwent endovascular coiling of pseudoaneurysm. Postcoiling DSA showed complete occlusion of pseudoaneurysm. The patient had uneventful postoperative period and showed good recovery.

E-094 an elusive case of iatrogenic bow hunter's syndrome, lessons learned

Purpose Bow Hunter’s syndrome (BHS), also known as rotational occlusion of the vertebral artery, contributes to posterior circulation ischemia secondary to dynamic compression of the dominant vertebral artery. This entity is most commonly attributed to cervical spondylosis or atlantoaxial hypermobility. The purpose of this case report is to illustrate an iatrogenic cause of BHS following cervical spine surgery. In addition, we emphasize the importance of using provocative DSA in diagnosing this condition in the setting of posterior circulation ischemia. Materials and methods 74 year old male presented in 2011 with a complaint of right upper extremity weakness and imaging findings of C1–2 instability and myelomalacia of the cervical spinal cord. The patient subsequently underwent C1–6 posterior fusion by orthopedic surgery and recovered uneventfully with initial postoperative radiographs demonstrating intact hardware. Routine 9 month follow-up radiographs revealed a fractured left C1 pedicle screw. 11 months post-op, patient developed transient visual symptoms prompting MRI of the brain, which was normal. The patient had a fall in early 2012 and the next cervical spine radiographs demonstrated fractures of both C1 screws, 14 months post-fusion. Over the next year, the patient presented to the ED multiple times for falls and eventually developed slurred speech and an unsteady gait. MRI brain revealed multiple posterior circulation infarcts of varying ages. CTA and MRA of the neck revealed a focal area of 30% stenosis of the left V3 segment. Conventional angiography without provocative maneuvers demonstrated a chronically occluded right vertebral artery and 30% stenosis of the distal left vertebral artery, interpreted as atherosclerotic. Despite maximal medical therapy including aspirin and plavix, in January 2015 he again developed new symptoms with decreased responsiveness, blurred vision, and right sided weakness. CTA of the neck demonstrated extrinsic compression of the left V3 segment due to adjacent fractured screw fragment. MRI revealed progression of the posterior circulation ischemic changes with no lesions in the carotid territories. Given the concern for extrinsic compression by the adjacent screw fragment, repeat DSA was requested. Results Right subclavian arteriogram with blood pressure cuff inflated again demonstrated chronic occlusion of the right vertebral artery. Left vertebral artery injection performed with the patient’s head in neutral position revealed 50% stenosis of the left vertebral artery V3 segment adjacent to the fractured screw, as seen on CTA. A provocative maneuver was then performed by having the patient turn his head to the left. Angiogram showed complete occlusion of the left vertebral artery confirming the diagnosis of BHS. Final angiogram with his head in neutral position showed flow had been restored. Conclusion We have demonstrated an elusive case of iatrogenic BHS. CTA and MRA are the primary imaging modalities for vascular assessment in the setting of cerebral ischemia. However, DSA with provocative maneuvers is an essential tool and may have led to an earlier diagnosis in this patient if performed on the initial angiogram. There should be an increased index of suspicion for BHS in patients with history of cervical spine surgery and infarcts confined to the posterior circulation. Disclosures P. Gulotta: None. G. Bennett: None. J. Milburn: 3; C; Penumbra.

The morphometric analysis of the V2 and V3 segments of the vertebral artery: Normal values on MDCT

A potential hazard in midline posterior fossa craniectomy may be the injury of vertebral artery. That's why vertebral artery evaluation prior to surgery may prevent dangerous complications. Advancements in multidetector computed tomography (MDCT) have provided detailed demonstration of the vertebral artery at the craniocervical junction and its relationships with atlas and axis. We aimed to define the normal anatomic relationship of the V2 and V3 part of the vertebral artery on MDCT. In total, 33 patients underwent MDCT angiography scan with suspected cranial aneurysm. V2 and V3 segments of vertebral artery were evaluated. Eight measurements (B, C, D, E, G, H, X, and Y line) were taken from MDCT images. For B and C, a line initially passing through the body of axis and spinous process and determining the midline was formed. Then, the vertical distance of vertebral artery from the level of transverse foramen of axis and loop to this midline was measured. For D and G, the vertical distance of vertebral artery to the midline from the upper and lower margin levels of transverse foramen of atlas was measured after a line establishing the midline passing through the anterior and posterior tubercles of atlas was drawn first. For E, transverse diameter of vertebral artery was measured at the loop level of V2 segment. For H, the vertical distance at the point where vertebral artery entered dura in the line passing from the midline of foramen magnum at anterior–posterior plane was measured. For X and Y, two different points of horizontal part of the vertebral artery were determined. One of these two points was the lateral one which was the origin of the horizontal part in the transverse foramen, the other was the intersection point on atlas. Average distances for both sides from transverse foramen of the axis, the loop of axoatlantal part and the lower border of the atlas of the vertebral artery to the midline were 20.97 mm on the right, 22.29 mm on the left; 27.19 mm on the right, 28.34 mm on the left; and 25.75 mm on the right and 27.21 mm on the left, respectively. Average distances for both sides from the upper border of the atlas, and at its penetration through dura were 27.40 mm on the right, 28.94 mm on the left; and 10.90 mm on the right and 10.93 mm on the left, respectively. Distances between spinous process and intersection of vertebral artery with horizontal part were 35.79 mm on the right and 36.63 mm on the left laterally, and 22.27 mm on the right and 22.62 mm on the left medially. MDCT angiography is a powerful test to demonstrate the vasculature of the head and neck. Bony structures and adjacent vessel morphology can be evaluated by this technique. The evaluation of craniocervical region prior to surgery with MDCT may be helpful to avoid intraoperative vascular injuries.

TYPE II PROATLANTAL INTERSEGMENTAL ARTERY ASSOCIATED WITH OBJECTIVE PULSATILE TINNITUS

The proatlantal intersegmental artery (PIA) is one of the primitive carotid-basilar anastomoses that exist transiently in the fetus. The PIA (also known as suboccipital artery) originates from the cervical internal carotid artery (ICA, type I) or external carotid artery (ECA, type II), runs upward, then curves dorsally to rest on the superior aspect of the transverse process of the atlas. It usually joins the V3 segment of vertebral artery (VA) or continues as the VA before entering the foramen magnum.1 Persistence of this artery in adulthood is rare and often an incidental finding. However, cerebral aneurysm, atypical cerebral infarct, intracranial hemorrhage, syncope, and headache have been attributed to the occasional persistent PIA in adults.2–5 Here, we present a case of objective pulsatile tinnitus associated with a persistent type II PIA. ### Case report. A 52-year-old woman had an insidious onset pulsatile tinnitus on her right side for 6 months. She had a depression history before but the tinnitus was not related to the mood change. There was no history of hypertension, diabetes mellitus, head injury, substance abuse, transient neurologic deficits, syncope, or headache. This disabling tinnitus resulted in sleep disturbance and poor concentration. Additionally, neck compression seemed to reduce the …

Interest of the vertebral artery V3 segment transposition. Report of 2 cases

Interest of the vertebral artery V3 segment transposition. Report of 2 cases

Angioplasty or stenting of extra- and intracranial vertebral artery stenoses.

To determine the feasibility and safety of angioplasty or angioplasty and stenting of extra- and intracranial vertebral artery (VA) stenosis. In 16 consecutive patients (9 men, 7 women; mean age 61 years, range 49-74 years) 16 stenotic VAs were treated with angioplasty or angioplasty and stenting. Eleven stenoses were localized in V1 segment, 1 stenosis in V2 segment and 4 stenoses in V4 segment of VA. Fourteen VA stenoses were symptomatic, 2 asymptomatic. The etiology of the stenoses was atherosclerotic in all cases. Angioplasty was performed in 8 of 11 V1 and 2 of 4 V4 segments of the VA. In 3 of 11 V1 segments and 2 of 4 V4 segments of the VA we combined angioplasty with stenting. The procedures were successfully performed in 14 of 16 VAs (87%). Complications were asymptomatic vessel dissection resulting in vessel occlusion in 1 of 11 V1 segments and asymptomatic vessel dissection in 2 of 4 V4 segments of the VA. One patient died in the 24-hr period after the procedure because of subarachnoid hemorrhage as a complication following vessel perforation of the treated V4 segment. Angioplasty or angioplasty and stenting of extracranial VA stenoses can be performed with a high technical success rate and a low complication rate. In intracranial VA stenosis the procedure is technically feasible but complications can be life-threatening. The durability and procedural complication rates of primary stenting without using predilation in extra- and intracranial VA stenosis should be defined in the future.