Bilateral Variation of the Vertebral Artery: Report of a Case and its Clinical Implication / Variación Bilateral de la Arteria Vertebral; Reporte de un Caso y su Implicancia Clínica

SUMMARY: There are many reports on anatomical variations of the vertebral arteries, which may be related to origin, trajectory, caliber, and side. Bilateral variations are less frequent, however, and less common are bilateral variants that differ from each other. The aim of this work was to report the presence of a bilateral variation of the vertebral artery and its functional and clinical implications. Dissection of a female cadaver, fixed in 10 % buffered formaldehyde, which had not undergone any previous surgeries in the study area and had anatomical variations in both vertebral arteries. In each one, follow-up was done from its origin to its end, determining its trajectory, diameters, branching, and anatomical relations. A left vertebral artery was found, starting in the aortic arch and making a sinuous trajectory of 4 curvatures to enter the transverse foramen of C4. The right vertebral artery began as the first branch of the subclavian artery. Its initial trajectory was rectilinear, followed by a right concave curve, a 360° loop that included a second ascending curve, and ended straight before entering the transverse foramen of C6. The coexistence of bilateral variations in the vertebral arteries is possible. This atypical situation can potentially generate vascular and neurological pathologies, but with different symptoms and causes. Knowing these variations and deliberately searching for them will enable the specialist to make a suitable differential diagnosis.

Existen múltiples reportes sobre variaciones anatómicas de las arterias vertebrales, las que se pueden relacionar con origen, trayecto, calibre y lateralidad. Sin embargo, las variaciones bilaterales son menos frecuentes, y menos común es que las variantes bilaterales sean diferentes entre ellas. El objetivo de este trabajo fue reportar la presencia de una variación bilateral de la arteria vertebral y su implicancia funcional y clínica. Disección en un cadáver de sexo femenino, fijado en formaldehido tamponado al 10 %, el cual no presentaba intervenciones quirúrgicas previas en la región de estudio y que tenía variaciones anatómicas en ambas arterias vertebrales. En cada una se realizó seguimiento desde su origen hasta su terminación, pudiendo determinar su trayecto, diámetros, ramificaciones y relaciones anatómicas. Se encontró una arteria vertebral izquierda originada en el arco aórtico, que realizaba un trayecto sinuoso de 4 curvaturas e ingresaba al foramen transverso de C4. La arteria vertebral derecha se originaba como primera rama de la arteria subclavia. Su trayecto inicial era rectilíneo seguido por una curva de concavidad derecha, un loop (giro) de 360° que incluía una segunda curva ascendente y terminaba en dirección recta antes de ingresar al foramen transverso de C6. La coexistencia de variaciones bilaterales en las arterias vertebrales es posible. Esta situación atípica, potencialmente puede generar en la persona patologías neurológicas de origen vascular, pero con sintomatología y causas diferentes. Conocer estas variaciones y realizar una búsqueda intencionada de ellas permitirá el especialista realizar un adecuado diagnóstico diferencial.

Morphometric Study of Atlas Vertebra In Relation to Sulcus Arteriae Vertebralis

Background: Atlas(C1) is an atypical cervical vertebra shaped like a ring. Important structures like the vertebral artery, suboccipital plexus of veins and first cervical nerve pass through it. Knowledge of the variability of C1 is important for neurosurgeons, orthopaedicians, otorhynologists and other physicians who in everyday practice are in contact with disorders of the spine and their consequences. So, this study was undertaken to assess the various dimensions of the C1 in relation to the vertebral artery groove. Methods and materials: Fifty dried human atlas vertebrae were studied. Various measurements were done and statistically analysed. Results: Antero-posterior diameter (APD) of Foramen transversarium(FT) was measured as 7.73 ± 1.04mm on the right and 7.62 ± 0.90mm on left side. Transverse Diameter(TD) of FT was observed as 6.12 ± 0.97mm on the right side and 6.02 ± 0.97mm on the left side. Outer Distance of Vertebral Artery Groove(VAG) was measured as 26.22 ± 2.32mm and 25.84 ± 1.85mm on the right and left sides, respectively. Inner Distance of VAG was observed as 13.10 ± 1.66mm on right and 13.17 ± 1.57mm on the left side. APD of Superior Articular Facet(SAF) was 21.52 ± 2.36mm on right and 21.51 ± 2.07mm on left side.TD of SAF was 11.21 ± 1.47mm on right and 11.32 ± 1.53mm on left side. APD of Inferior Articular Facet(IAF) was observed as 17.54 ± 1.50mm on right and 17.70±1.60mm on left side. TD of IAF was observed as 14.99 ± 1.65mm on the right side and 14.94 ± 1.51mm on left side. Distance between lateral-most edge of both Foramen Transversaria was measured as 56.37 ± 4.11mm and distance between medial-most edge of both Foramen Transversaria was 44.78 ± 3.67mm. MaximumTD of Atlas was measured as 72.09± 5.59mm. Conclusion: The study will generate information that would be useful for geometric modelling of vertebrae and give necessary morphometric data on human atlas vertebra in Indian population.

Study of Incidence of Ponticulus Posterior In Dry Human Atlas Vertebra and Its Clinical Significance

Background: Atlas is the first cervical vertebra. The vertebral artery lies in the groove on posterior arch of the atlas. The vertebral artery groove may sometimes get converted into a foramen. This is commonly known as ponticulus posterior (ponticulus posticus) or arcuate foramen of the atlas. These foramina may be complete or incomplete. This can lead to compression of the vertebral artery and produce symptoms like headache, syncope, altered consciousness etc. It can also complicate manipulations of the cervical spine by reducing the blood flow during extreme rotations of head and neck. It is also associated with vertebrobasilar artery stroke So, neurosurgeons or orthopaedic surgeons who operate in this area should have a detailed knowledge of variations of groove for the vertebral artery. Materials and Methods: The present study was conducted on 50 dried and fully ossified adult human atlas of unknown age and sex collected from the department of Anatomy, Government Medical college, Nagpur. Each atlas vertebra was carefully observed for the presence or absence of complete or incomplete ponticuli on superior surface of posterior arch of atlas. Results: Out of the 50 vertebra studied 7(14%) showed the presence of Ponticuli. Ponticuli were incomplete in all 7 atlas vertebras. Complete ring was not observed in any of the atlas vertebra .Out of the 7 ponticuli 6(12%) were found to be unilateral and in only 1 (2%) case it was found to be bilateral. Out of the 6 ponticuli 4(8%) were noticed on the Left side and 2(4%) were present on the right side. Conclusion: Presence of incomplete ponticulus posterior might cause cervical pain and even cerebrovascular disorders due to pressure on third part of vertebral artery present in the vertebral artery groove. This anatomical knowledge is important for neurosurgeons, orthopaedic surgeons, radiologists and clinicians while dealing with this region.

Predictors of delayed function independence in patients with acute vertebrobasilar artery occlusion achieved successful recanalization after endovascular therapy / 国际脑血管病杂志

Objective:To investigate the prevalence and predictors of delayed function independence (DFI) in patients with acute vertebrobasilar artery occlusion (VBAO) achieved successful recanalization after endovascular therapy.Methods:Patients with acute VBAO received endovascular treatment in the Departments of Neurology, the First Affiliated Hospital of University of Science and Technology and General Hospital of Eastern Theater Command, PLA from December 2015 to December 2018 were retrospectively enrolled. The demographic, clinical, laboratory and imaging data were collected. Early functional independence (EFI) was defined as the modified Rankin Scale score 0-2 at discharge, and DFI was defined as the modified Rankin Scale score 0-2 at 90 d after discharge for non-EFI patients. Multivariate logistic regression analysis was used to determine the independent predictors of DFI. Results:A total of 122 patients with acute VBAO were included. Their age was 61.8±11.9 years old and 91 (74.6%) were male. The median Glasgow Coma Scale (GCS) score was 7, the median National Institutes of Health Stroke Scale (NIHSS) score was 26.5, and the median posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) score was 9. Twenty-four patients (20.0%) had EFI; of the 98 patients with non-EFI, 18 (18.4%) had DFI. Multivariate logistic regression analysis showed that male (odds ratio [ OR] 0.038, 95% confidence interval [ CI] 0.002-0.658; P=0.025), cardiogenic embolism ( OR 0.116, 95% CI 0.023-0.579; P=0.009), baseline NIHSS score ( OR 1.136, 95% CI 1.040-1.242; P=0.005) and lung infection ( OR 6.089, 95% CI 1.451-25.562; P=0.014) were the independent predictors of DFI. Conclusions:Nearly 1/5 of the non-EFI patients have DFI. Male, cardiogenic embolism, lower baseline NIHSS score and without pulmonary infection are the independent predictors of DFI.

Thoracic Endovascular Aortic Repair for Chronic Aortic Dissection with an Isolated Left Vertebral Artery / 日本心臓血管外科学会雑誌

Thoracic endovascular aortic repair (TEVAR) is valuable in the treatment of type B aortic dissection. An isolated left vertebral artery (ILVA) is a common anomaly of the aortic arch. The ILVA is covered during TEVAR in specific cases; however, whether the ILVA should be reconstructed in all cases remains controversial. We report a case of TEVAR performed for chronic aortic dissection in a patient with an ILVA. A 57-year-old woman with an ILVA had a type B acute aortic dissection one year prior to presentation and underwent TEVAR owing to dilation of an ulcer-like projection. We performed ILVA-left common carotid artery (LCCA) anastomosis and LCCA-left axillary artery bypass prior to TEVAR using our usual procedure. The postoperative course was favorable without any major complication. ILVA reconstruction may reduce the incidence of postoperative stroke and spinal cord injury. Usually, an ILVA is easily accessible through the supraclavicular approach, and the anatomical position of the vessel facilitates ILVA-LCCA anastomosis. ILVA reconstruction requires additional features and further consideration.

Clinical Effect of Surgical Reconstruction of Extracranial Vertebral Artery / 中国医学科学院学报

Objective To evaluate the effect of surgical reconstruction of extracranial vertebral artery and to summarize the experience. Methods The clinical data of 15 patients undergoing surgical reconstruction of extracranial vertebral artery from September 2018 to June 2022 were collected.The operation methods,operation duration,intraoperative blood loss,operation complications,and relief of symptoms were retrospectively analyzed. Results Eleven patients underwent vertebral artery (V1 segment) to common carotid artery transposition,two patients underwent endarterectomy of V1 segment,two patients underwent V3 segment to external carotid artery bypass or transposition.The operation duration,intraoperative blood loss,and blocking time of common carotid artery varied within 120-340 min,50-300 ml,and 12-25 min,with the medians of 240 min,100 ml,and 16 min,respectively.There was no cardiac accident,cerebral hyperperfusion syndrome,cerebral hemorrhage or lymphatic leakage during the perioperative period.One patient suffered from cerebral infarction and three patients suffered from incomplete Horner's syndrome after the operation.During the follow-up (4-45 months,median of 26 months),there was no anastomotic stenosis,new cerebral infarction or cerebral ischemia. Conclusion Surgical reconstruction of extracranial vertebral artery is safe and effective,and individualized reconstruction strategy should be adopted according to different conditions.

Experimental study of improved sclerotherapy injection in rat model of vertebral arteriocervical spondylopathy / 中国骨伤

OBJECTIVE@#To improve the rat model of cervical spondylosis of vertebral artery type (CSA) induced by injecting sclerosing agent. To evaluate the efficacy of injecting sclerosing agent to induce CSA.@*METHODS@#Forty Health SPF SD rats(20 males and 20 females), were randomly divided into two groups:the model group (20) and the blank group (20). All the animals were followed up for 4 weeks for the observation of general situation, transcranial Doppler(TCD) detection of blood flow velocity, pulsatility index and resistive index of the vertebral artery, measurement of mental distress by open-field test.@*RESULTS@#One to two days after establish the animal model, rats in the model group appeared apathetic with decreased autonomic activities, trembling, squinting, increased eye excrement, etc., and no rats died during the experiment. The mean blood flow velocity of the model group was lower than that of the blank group (P<0.05), and the pulsatilit index and resistive index of the model group were higher than that of the blank group (P<0.05). The mental distress of the model group was significantly higher than that of the blank group.@*CONCLUSION@#The modified injection of sclerosing agent is a practical method to establish the rat model of CSA, with high success rate, high stability, low mortality and simple operation.

Carotid endarterectomy combined with vertebral artery transposition treating vertebral artery V1 segment stenosis combined with ipsilateral carotid artery stenosis / 中国胸心血管外科临床杂志

@#Objective    To explore the treatment outcome of carotid endarterectomy combined with vertebral artery transposition in patients with severe stenosis to occlusion of the vertebral artery V1 segment and the ipsilateral carotid artery. Methods    From June 2017 to September 2020, patients with severe stenosis to occlusion of the vertebral artery V1 segment and the ipsilateral carotid artery treated with carotid endarterectomy combined with vertebral artery transposition in Fuwai Hospital were retrospectively analyzed. Results    Finally 12 patients were enrolled, including 10 males and 2 females with an average age of 67.8±6.0 years. Twelve patients were successfully operated and the follow-up time was 1-3 years. The stenosis degree of the V1 segment of the vertebral artery decreased from 83.5%±11.8% to 24.9%±14.3% (P<0.001). The stenosis degree of carotid artery decreased from 85.6%±11.0% to 0% (P<0.001). Postoperative follow-up showed that the symptoms of symptomatic patients before surgery improved. The 1-year and 3-year patency rates were 100.0%, and there were no peripheral nerve injury complications, perioperative deaths or strokes. Conclusion    Carotid endarterectomy combined with vertebral artery transposition can treat ipsilateral carotid artery  stenosis and vertebral artery stenosis at the same time, improve blood supply to the brain, improve patients' symptoms and has high promotion value.

Clinical features and stroke etiology in 10 patients with bilateral middle cerebellar peduncle infarctions: a preliminary study / 中华神经科杂志

Objective:To characterize clinical and neuroimaging features, etiologies, and mechanisms of bilateral middle cerebellar peduncle (MCP) infarctions.Methods:Consecutive patients with bilateral MCP infarctions treated in the Beijing Tiantan Hospital, Capital Medical University between January 1, 2020 and April 30, 2022 were enrolled in this retrospective study. The demographic data, vascular risk factors, clincial manifestations and the National Institutes of Health Stroke Scale (NIHSS) scores were collected. Brain diffusion-weighted imaging was used to assess the regions of cerebral infarction, and the extracranial and intracranial segments of the vertebrobasilar artery were evaluated using magnetic resonance angiography, or computed tomography angiography. The stroke etiology and underlying mechanism were evaluated according to the Chinese Ischemic Stroke Subclassification.Results:Ten patients with bilateral MCP infarctions (8 men and 2 women) were analyzed ultimately. The onset age were 51.0-86.0 (64.8±11.4) years. NIHSS scores were 2.0-12.0 (4.9±2.9) points at admission. All patients had vascular risk factors, most of which were hypertension (10 cases) and dyslipoproteinemia (8 cases). The most common clinical manifestations were vertigo (10 cases), followed by ataxia (9 cases) and dysarthria (8 cases). Four cases were isolated bilateral MCP infarctions, while 6 patients were combined with other vertebrobasilar artery infarctions, 4 of which were combined with cerebellar hemisphere infarctions, consistent with the clinical symptoms. The etiology in all patients was large atherosclerosis (severe stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery; 9 cases). Five patients were classified as hypoperfusion/impaired emboli clearance, while 4 patients were considered as artery-to-artery embolism, and 1 was considered as the parent artery (plaque or thrombosis) occluding penetrating artery.Conclusions:Bilateral MCP infarctions are an extremely rare cerebrovascular disease characterized by vertigo, ataxia, and dysarthria. Cerebral infarction can be isolated or often combined with cerebellar hemisphere infarction. The etiology was mostly stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery.

Axial instrument strategy for atlantoaxial dislocation with complex artery variation / 中华骨科杂志

Objective:To evaluate the axial instrument strategy for atlantoaxial dislocation with complex vertebral artery variation.Methods:A total of 55 patients with atlantoaxial dislocation who underwent surgical treatment from January 2019 to December 2021 were retrospectively analyzed, including 14 males and 41 females, aged 54.0±12.8 years (range, 22-78 years). Among these patients, 10 patients with unilateral vertebral artery high ride with contralateral vertebral artery occlusion, 30 patients with bilateral vertebral artery high ride with single dominant vertebral artery, 15 patients with bilateral vertebral artery high ride. All patients underwent posterior reduction and internal fixation. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the postoperative efficacy.Results:All patients completed the surgery successfully with a follow-up time of 14.6±5.5 months (range, 6-24 months). C 2 pedicle screw fixation was performed on the non-dominant side of unilateral vertebral artery high ride and the non-dominant side of bilateral vertebral artery high ride with one dominant vertebral artery (40 vertebraes). The dominant side of unilateral high vertebral artery and bilateral high vertebral artery with one dominant vertebral artery was fixed with C 2 medial "in-out-in" screw (10 vertebraes), C 2 isthmus screw (21 vertebraes), C 2 without screw (9 vertebraes) only extended the fixed segment. For bilateral vertebral artery high ride patients, one side was used C 2 "in-out-in" pedicle screws (right 10 vertebraes, left 5 vertebraes), and the other side was fixed with C 2 medial "in-out-in" screw (8 vertebraes), C 2 isthmus screw (5 vertebraes), C 2 without screw only extended the fixed segment (2 vertebraes). The JOA scores were 8.5±1.8, 13.9±1.3, and 14.4±1.1 preoperatively, 6 months postoperatively, and at the final follow-up, respectively, with statistically significant differences ( F=279.40, P<0.001). JOA at 6 months postoperatively and at the final follow-up was greater than preoperatively, and the differences were statistically significant ( P<0.05), whereas the differences in JOA scores at 6 months postoperatively and at the final follow-up was not statistically significant ( P>0.05). Preoperative, 6 months postoperatively and final follow-up cervical VAS scores were 3.7±1.9, 2.1±0.9 and 1.6±1.0, respectively, with statistically significant differences ( F=39.53, P<0.001). The cervical VAS at 6 months postoperatively and at the last follow-up was less than that before surgery, and the differences were statistically significant ( P<0.05). Cervical VAS scores at 6 months postoperatively were greater than at the last follow-up, with a statistically significant difference ( P<0.05). Conclusion:For patients with atlantoaxial dislocation with complex vertebral artery variation, C 2 lateral "in-out-in" screw, C 2 medial "in-out-in" screw, isthmus screw fixation or C 2 without screw only extended the fixed segment can obtain good clinical efficacy.

Lateral medullary syndrome: an unwanted ischemia to identify early

Lateral medullary syndrome also referred to asWallenberg syndrome, posterior inferior cerebellar artery (PICA) syndrome, orvertebral artery syndrome is a cluster of neurological symptoms and signs brought on by obstructions in the blood vessels supplying the medulla, which causes ischemia or infarction of the brainstem. The vertebral artery or the posterior inferior cerebellar artery are the arteries most frequently affected with lateral medullary syndrome. The most prevalent symptom istransient ischemic attack (TIA) with dizziness or vertigo andatherosclerosis in the posterior cerebral circulationbeingthe most common cause. Lateral Medullary Syndrome patients sufferfrom strokes or infarction and alsopresentwith vomiting,nausea, gait impairment, instability, hoarseness, and swallowing difficulties. Depending on the particular nuclei and fibersinvolved, different indications will appear. CT/MRI imaging is used to diagnose conditions. The majority of management is supportive, including risk factor reduction for additional ischemia events as well as speech and occupational therapy following an acute intervention. In this review article, we discuss the etiopathogenesis and factors leading to lateral medullary syndrome along with a comprehensive discussion on its clinical features, challenges in diagnosis, and treatment.

Trauma penetrante de arteria vertebral. Del control de daños a lo endovascular

Introducción: El trauma penetrante de la arteria vertebral es extremadamente infrecuente. Objetivo: Aportar evidencia clínica mediante la revisión de una serie de casos. Materiales y Método: Se analizan cuatro casos de trauma penetrante con compromiso de la arteria vertebral entre los años 2020 y 2021, manejados en la unidad de trauma y urgencias del Complejo Asistencial Dr. Sótero del Río. Resultados: Se presentan cuatro casos clínicos relatando su proceso diagnóstico y manejo. Discusión: La evidencia de compromiso traumático de arteria vertebral es escasa. Reconocer su compleja anatomía y variada clínica resultan trascendentales para su adecuado manejo. Ante sospecha de este tipo de lesión, la angiografía por tomografía computada es el estudio de elección cuando se presentan hemodinámicamente estables. El abanico de opciones terapéuticas incluyen: observación, terapia antitrombótica o con antiagregantes, terapia endovascular o cirugía abierta. Conclusión: El trauma penetrante de arteria vertebral es una condición infrecuente, sin embargo, su diagnóstico y manejo deben ser conocidos por el cirujano.

Introduction: Traumatic involvement of the vertebral artery is extremely rare and difficult to diagnose. Objective: To provide clinical evidence by reviewing a case series. Materials and Method: We analyze four cases of penetrating trauma with involvement of the vertebral artery between 2020 and 2021, managed in the trauma and emergency unit of the Dr. Sótero del Río Care Complex. Results: Four clinical cases are presented describing diagnosis and management process. Discussion: There is little evidence of traumatic involvement of the vertebral artery. Recognizing its complex anatomy and varied clinic are transcendental for its proper management. When this type of lesion is suspected, computed tomography angiography is the choice study when hemodynamically stable. The range of therapeutic options include observation, antithrombotic or antiplatelet therapy, endovascular therapy or open surgery. Conclusion: Penetrating trauma of the vertebral artery is an uncommon condition, however, its diagnosis and management should be known to the surgeon.

Normal and Abnormal Development of Left Vertebral Artery and Its Implications in Cervical Region Surgery

Aortic arch (AA) anomalies occur in approximately 3-5% of cadavers, but these atypical branches remain a point of discussion in cervical region surgery. This case report describes a 73-year-old Caucasian female who died of renal failure following a complicated urinary tract infection whose left vertebral artery (LVA) originated from the AA between the left common carotid and subclavian arteries. The preforaminal part of the LVA was 5 mm in diameter and entered the C6 transverse foramen while the right vertebral artery (RVA) arose from the right subclavian was 6.5 mm in diameter and entered the C5. Embryologically, VAs are formed during weeks four through eight by development of longitudinal anastomoses linking the cervical intersegmental arteries (ISA). The ISA regress except the seventh, which becomes the proximal subclavian artery, the point of origin of the adult VA. Persons with LVA that arises from the AA may be asymptomatic; however, secondary dilatation of the RVA may be implicated in the development of cerebrovascular disorders and atherosclerotic changes due to increased blood flow. Additionally, the anatomical positioning of a left vertebral artery is important when considering an anterior approach for cervical spine surgery and other head-neck procedures when soft structures arteries, veins and muscles are retracted to reach the cervical spine.

A case of subclavian steal syndrome

Subclavian steal syndrome is a relatively rare condition that results from occlusion of the subclavian artery proximal to the origin of the vertebral artery. This causes a reversal in the direction of the blood flow in the vertebral artery, leading to symptoms of vertebrobasilar insufficiency. In this article, we report a case of subclavian steal syndrome in a 55 year old male, who presented with giddiness, and variation in blood pressures in both upper limbs, was investigated with doppler and MR angiography. This article emphasises physical examination with discrepancy in pulse and blood pressure should bring attention to diagnosis of this syndrome.

Fijación con tornillos transarticulares C1-2 combinada con técnica de Gallie en luxación atloaxoidea / C1-2 transarticular screw fixation combined with Gallie technique in atloaxial dislocation

RESUMEN Introducción: existen múltiples técnicas quirúrgicas para tratar la inestabilidad del complejo atlantoaxial. La fijación con tornillos transarticulares C1-2 (técnica de Magerl) ha mostrado altos índices de fusión, y puede ser combinada con los sistemas de alambrado descritos inicialmente, para garantizar mayor estabilidad al constructo. Presentación de caso: masculino, 62 años, que luego de una caída de dos metros, es traído a la institución con dolor cervical y con imposibilidad para mover las extremidades. Al examen neurológico, presentaba un grado B en la American Spinal Injury Classiffication Scale. Se diagnostica fractura odontoidea conminuta y luxación atloaxoidea. Se le aplica tracción cervical con lo que se logra la alineación vertebral. Se planifica tratamiento quirúrgico mediante técnica de Magerl. Ante trayectoria subóptima del tornillo inicial, se combina con fusión atloaxoidea posterior, mediante técnica de Gallie. Se mantuvo inmovilización externa durante dos semanas. Al egreso hospitalario, el paciente logra la deambulación, aunque con disparesia braquial con predominio distal. En estudios radiológicos evolutivos, no se observa fallo del sistema de instrumentación. Conclusiones: en este caso la utilización de la técnica de Gallie, ante la malposición de uno de los tornillos transarticulares C1-2, permitió conservar la estabilidad del constructo.

ABSTRACT Introduction: Multiple surgical techniques exist to treat instability of the atlantoaxial complex. Transarticular C1-2 screw fixation (Magerl's technique) has shown high fusion rates, and can be combined with the initially described wiring systems to guarantee greater stability to the construct. Case presentation: male, 62 years old, who after a two-meter fall, was brought to the institution reporting cervical pain and inability to move the limbs. On neurological examination, he had a grade B on the American Spinal Injury Classiffication Scale. A comminuted odontoid fracture and atloaxial dislocation were diagnosed. Cervical traction was applied and vertebral alignment was achieved. Surgical treatment was planned using Magerl's technique. Given the suboptimal trajectory of the initial screw, it was combined with posterior atloaxoid fusion, using Gallie technique. External immobilization was maintained for two weeks. At hospital discharge, the patient achieved ambulation, maintaining brachial dysparesis with distal predominance. In evolutionary radiological studies, no failure of the instrumentation system was observed. Conclusions: In our case, the use of the Gallie technique, in view of the malposition of one of the C1-2 transarticular screws, allowed preserving the stability of the construct.

Arcuate Foramen: An Anatomical Variation in the Atlas Vertebrae

Background: Arcuate foramen is a variation in the posterior arch of atlas vertebrae. It is commonly called as Kimmerle’s anomaly, also known as Ponticulus Posticus. It is the product of the complete or incomplete ossification of the posterior atlantooccipital membrane over the vertebral artery groove resulting in the formation of arcuate foramen containing the vertebral artery and the posterior branch of the first cervical spinal nerve. Aims: The aim of the present study was to identify the percentage of incidence of arcuate foramen in the atlas and its clinical important. Materials and Methods: The study was conducted in the Department of Anatomy, Katihar Medical College, Katihar, India with 32 adult dried atlas vertebrae. Results: We found four (12.5%) atlas with arcuate foramen. One atlas having complete arcuate foramen and three having partial complete arcuate foramen. Conclusion: Awareness of this type of variation is very important for neurosurgeons and radiologist during their clinical practice. The presence of the arcuate foramen would also complicate screw placement during surgery. Clinical prescreening for signs of vertebrobasilar insufficiency is important for chiropractic and manual therapies.

Morphometric Analysis of Vertebral Artery Groove in Human Atlas Vertebra in South Indian Population

Introduction: Recent trends like pedicle screws and other instrumentation of cervical vertebra are on the rise. However, proximity of vertebral artery coursing in vertebral artery groove (VAG) on the superior surface of the posterior arch of atlas poses a unique challenge to surgeons performing these procedures. Such vascular injuries though rare, are not uncommon and may pose immediate to delayed complications. Radiological studies of atlas vertebra & VAG are being extensively done with CT and MR Angiography, but morphometric studies of VAG in atlas vertebra in South Indian population is lacking. Aims: To understand the morphology and dimensions of the vertebral artery groove and its variations if any, in dry atlas vertebra of South Indian population. Settings and Design: Descriptive observational study Methods and Material: 50 dried adult human atlas vertebra of unknown age & sex from the Anatomy Department, PSGIMS & R, Coimbatorewere studied. Intact cervical vertebrae without any degenerative or traumatic disorders were included. The morphometry of VAG and its distance from midline were evaluated through six linear measurements.The parameters were inner and outer lengths of the groove, width & thickness of the groove and the distance of its medial most and lateral most edges from the midline on both sides. Statistical analysis used: SPSS software Results: There is no statistically significant difference between mean values on right and left side for inner length, outer length, width and thickness of vertebral artery groove. The mean inner and outer distance of the vertebral artery groove from the midline on the right is higher than the left. Conclusions: The present study provides morphometric data of VAG & recommends a safe zone of 11.82 mm from midline for instrumentation in posterior spinal surgeries to minimize vertebral artery injuries.

The effect of in-out-in axis pedicle screws on the vertebral artery in the posterior occipitocervical surgery / 中华创伤骨科杂志

Objective:To observe the effect of insertion of in-out-in axis pedicle screws on the vertebral artery in the posterior occipitocervical surgery for atlantoaxial subluxation or instability.Methods:The data of 52 patients with atlantoaxial dislocation or instability were analyzed who had been treated by internal fixation with in-out-in pedicle screws in the posterior occipitocervical surgery from January 2015 to February 2021 at Department of Spine and Spinal Cord Surgery, Henan Provincial People's Hospital. There were 30 males and 22 females, aged from 17 to 65 years (mean, 41.2 years). There were 26 cases of unilateral vertebral artery high-riding, 3 cases of bilateral high-riding, 19 cases of unilateral narrow pedicle due to C2 and C3 fusion, and 4 cases of bilateral narrow pedicles. X-ray, CTA and MRI were performed before and 3 days after surgery. The patients' clinical symptoms were recorded. CTA was used to measure the diameter of the vertebral artery at the transverse foramina of C 2 and C 3 and to observe the effect of in-out-in screws on the morphology of the vertebral artery. X-ray and CT examinations were performed at 6 months after surgery to observe the bone fusion. Results:The surgery went on uneventfully in all the patients. In the 9 cases undergoing anterior and posterior surgery, the operation time averaged 271.2 min (from 213 to 352 min) and the bleeding volume 471.5 mL (from 230 to 830 mL). In the 43 cases undergoing posterior surgery, the operation time averaged 171.6 min (from 131 to 226 min) and the bleeding volume 395.9 mL (from 170 to 660 mL). There was no such complication as spinal or vascular injury. The CTA reexamination 3 days after surgery showed that the diameter of the vertebral artery was (2.92±0.55) mm and (3.04±0.54) mm, respectively at the cervical 2 and 3 transverse foramina, showing no significant change compared with the preoperative values [(2.91±0.68) mm and (3.11±0.50) mm] ( P>0.05) and that the vertebral artery was displaced externally and inferiorly in 21 cases. Follow-ups for all patients ranged from 7 to 24 months (mean, 11 months). At 6 months after surgery, bone fusion was observed by imaging and no breakage or displacement of the internal fixation was observed. Conclusion:The in-out-in pedicle screws in the posterior occipitocervical surgery may have little impact on the vertebral artery, leading to reliable clinical outcomes.

Translocation of the Isolated Left Vertebral Artery during Thoracic Endovascular Stent-Graft Repair / 日本心臓血管外科学会雑誌

Spinal cord injury (SCI) is a main concern in patients who undergo thoracic endovascular therapy (TEVAR), because the blood flow of the vertebro-basilar artery may be reduced due to the left subclavian artery (LSA) occlusion. If the left vertebral artery originates directly from the aorta, which is called the isolated left vertebral artery (ILVA), a technical consideration for strategies regarding blood perfusion of the ILVA during TEVARs is required. We hereby aim to report three patients (No.1, No.2, and No.3) who underwent an ILVA translocation and TEVAR with Zone 2 landing for aortic dissection. The diameter of the ILVA was 4.2, 2.3, and 2.2 mm, respectively, and the right vertebral artery (RVA) was dominant in all cases. In Patient No.1 and No.2 (ILVA diameter: 4.2 and 2.3 mm, respectively), the ILVA was anastomosed directly to the left common carotid artery. In Patient No.2, the translocated ILVA was occluded resulting in SCI, but the SCI improved when blood pressure was augmented. In Patient No.3 (ILVA diameter: 2.2 mm), the saphenous vein graft was interposed between the ILVA and the bypass artery because the ILVA diameter was small, but postoperatively, the ILVA remained patent, and no paraplegia was observed. The occlusion of ILVA could cause SCI, even if the RVA is larger than the LVA. Reconstruction of the ILVA is a critical procedure to prevent postoperative SCIs in patients undergoing TEVARs.

Modified vertebral-carotid transposition treating stenosis at V1 segment of vertebral artery / 中国胸心血管外科临床杂志

@#Objective    To investigate the treatment of modified vertebral-carotid transposition (VCT) in patients with severe stenosis or occlusion at V1 segment of vertebral artery. Methods    A retrospective study of 13 patients with severe stenosis or occlusion at V1 segment of vertebral artery treated by modified VCT in our hospital from October 2016 to December 2018 was done. There were 10 males and 3 females with an average age of 70.5±7.1 years. Results    The operation was successful in this series of patients. The follow-up duration was 1-3 years. The stenosis degree of the V1 segment of the vertebral artery decreased from 86.8%±7.5% to 17.4%±14.5%. All patients achieved remission of symptoms after the surgery. Temporary peripheral nerve injury occurred in 6 patients. Four patients with neurological complications relieved during follow-up. The patency rate was 100.0% at postoperative 1 and 3 years. There was no perioperative death, stroke or re-intervention. Conclusion    Modified VCT can precisely restore the distal blood flow of patients with severe stenosis or occlusion at V1 segment of vertebral artery, and relieve their symptoms.