Side Of Vertebral Artery Research Articles

Low-dose three-dimensional CT angiography for the evaluation of posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: a quantitative anatomical comparison study of the rotational and neutral positions

To investigate the changes in relevant anatomical parameters of posterolateral protrusion of the vertebral artery (VA) between head-neck rotational and neutral positions using low-dose three-dimensional computed tomography angiography (3D-CTA). Low-dose 3D-CTA images obtained for various craniocervical diseases in 36 non-dominant VA side patients with neutral, left and right head-neck rotational positions were evaluated. The relevant parameters from superior and inferior views, including external diameter (ED), internal diameter (ID), transverse diameter (TD), heights and diameters of posterolateral protrusion of the VA over the posterior arch of the atlas in the neutral and rotational positions, were recorded and compared. There was no significant differences in the rotational angle (left/right: 31.23±6.60/29.94±6.09°, p>0.05). There were no significant differences in heights and diameters of bilateral VA between rotational and neutral positions (all p>0.05). The contralateral ID, ED, and TD of the rotational positions were significantly shorter than those of the neutral position (all p<0.05), while there were no significant differences in the three ipsilateral diameters (all p>0.05). Posterolateral protrusion of the VA is not uncommon in the population, and surgeons should be aware of its presence, especially the increased possibility of injury to the VA caused by head-neck rotation, during the operation; thus, preoperative evaluation by low-dose 3D-CTA should be considered.

Vertebral Artery Variations at the Craniovertebral Junction in “Sandwich” Atlantoaxial Dislocation Patients

ObjectiveTo summarize the vertebral artery (VA) pattern of 96 “sandwich” atlantoaxial dislocation (AAD) patients and to describe the strategies of reducing the injury of VA during surgery. MethodsFrom 2009 to 2020, we retrospectively reviewed the 3-dimensional computed tomography angiography data of 96 AAD patients combined with atlas occipitalization and C2–3 fusion, which were diagnosed as “sandwich” AAD and 96 patients as control group patients who were without atlas occipitalization, C2–3 fusion and any other cervical bone deformity at our institution. The variations of each side of VA were described in 3 different parts (C0–1, C1–2, and C2–3) according to the characteristics of the 3-part pathological structures in “sandwich” subgroup. ResultsOne hundred ninety-two sides of VAs in every group of patients were analyzed and every VA was described separately at 3 different level regions. There were different variations in these 3 different regions: 4 variations in the upper fusion region, 5 variations in the sandwiched region, and 6 variations in the lower fusion region in sandwich AAD patients. And the rate of VA deformity in sandwich AAD patients was much higher and more types of VA variations existed. ConclusionIn “sandwich” AAD patients, deformities of vertebral arteries in craniovertebral junction are more common, and the same VA may have deformities at different levels that severely affect surgical procedures. Therefore, preoperative imaging examination of VA for “sandwich” AAD patients is vital of guiding surgeons to avoid injury of VA during surgery.

Variations of the extracranial segment of vertebral artery as a bleeding risk factor.

Standart interventional procedures such as screw instrumentation, aortic arch endovascular surgery and cervical nerve blockade may be of fatal risk due to anatomic reason of variations in the proximal part of the vertebral artery (VA). The aim of this study is to study the VA variations of the extracranial segments to evaluate the frequency of the incident to demonstrate the importance of clinical condition strategy. The prevalence of variations and morphometric measurements of the VA in three-dimensional computed tomographic angiography (3D-CTA) scans were studied. Total 400 VA was investigated for the aortic arch origin of the VA, diameter of the VA, its level of entry into the transverse foramen, the dominance sides, and related basilar artery course. 3D-CTA radiographs of 200 Anatolian patients (120 men and 80 women with age range 17-90years). In most cases (approximately 94%), both sides of VA were the first branch of subclavian artery. While all the right VAs was branched from the subclavian artery, 6% of the left VAs were branched from the aortic arch. 2/3 of them originated from the proximal of the subclavian artery and 1/3 from the distal. The VA which were originating from the proximal of the classical anatomic pattern tended to enter the transverse foramen more distally than C6 level. VAs with a different level of entry than C6 are left-sided and aortic arch originated (out of 8 cases 3 had a level of entry at C5 and 2 at C4). The outer diameter ranges of the prevertebral part of the VA of subclavian origin and left VA of aortic arch origin were 3.2-3.6mm and 3.2-3.6mm, respectively. While the diameters of the right and left VAs were almost the same in approximately 20% cases, the left VA was dominant in up to 60% of cases. A significant relationship was found between the side of the dominant VA and in the course of the basilar artery. The relationship between the dominant side of VA and the course of the basilar artery of its own vessel has never been reported elsewhere. Such anatomical variations, routine preoperative 3D-CTA evaluation is mandatory to prevent the VA injury when C5-C2 instrumentation, anterior cervical decompression, cervical nerve blockade and aortic arch surgery are planned.

Is there a correlation between hand preference and vertebral-subclavian artery diameter and vertebral artery flow volume?

Aim: During diagnostic and therapeutic cerebral angiographic studies, the prediction of the dominant vertebral artery side is highly important. The reason for right and left vertebral artery diameter asymmetry is not clear. We believe there may be a correlation between hand preference and vertebral artery flow volume dominance and subclavian artery diameter. Material and Methods: A total of 112 patients were included in this study. We examined 14 left-handed and 98 right-handed individuals. Ultrasonographic measurements of the vertebral arteries were performed with 7,5 Mhz linear probing between the fifth and sixth cervical vertebrae at each side. Vertebral artery diameter and volume flow and subclavian artery diameters were measured and average values recorded. Normality analysis was conducted by one-sample Kolmogorov-Smirnov testing. The paired-sample t-test was applied to compare the left and right side measures. Results: There were no significant differences in the diameter or volume flow of the right and left vertebral arteries (VA) between right- and left-handed individuals (p>0.05). Beside this, no significant difference was found in the diameter of either the subclavian artery between right- and left-handed individuals (p

Sizes of the transverse foramina correlate with blood flow and dominance of vertebral arteries

Background contextKnowing the side of the dominant vertebral artery (VA) may be of utmost importance if the VAs are at risk during spine surgery. Determination of the size of VAs is obtained by using Doppler ultrasonography or angiography. Because VA is the main anatomic structure occupying the transverse foramina (TF), it may be assumed that size of TF and blood flow of VAs should be proportional. PurposeTo investigate if there is a correlation between the sizes of TF and the flow of VAs and determine the diagnostic accuracy of measuring TF to predict dominant side of VA. The specific hypothesis was that the larger side of TF corresponds to the side of the dominant VA. Study designThis is a morphologically based, prospectively designed, single-center study. Thirty patients (14 male, 16 female) who were treated for degenerative spinal pathologies were included. Patients with cervical fractures, occluded VA, prominent degenerative changes affecting TF, deformity, or previous cervical instrumentation were excluded from the study. Outcome measuresIn all patients, computed tomography of the cervical spine and Doppler ultrasonography of VAs were obtained for morphometric analysis. MethodsAxial computed tomography cuts at the C6 vertebral level were taken. Two measurements were performed for each foramen: its right to left width and its anteroposterior depth. Blood flow volumes of bilateral VAs were measured using color Doppler. ResultsDiameters of TF ranged between 2.2 and 7 mm, and its width was generally slightly larger than the depth. Transverse foramina were always asymmetric, with no right or left side preference. There was a strong correlation between TF diameters and blood flow of VAs. Between TF width and VA blood flow, the Pearson correlation coefficient was 0.59 (p=.001) for right side and 0.72 for left side (p<.0001). The side of the larger TF matched with the side of dominant VA in 28 of 30 cases (93.3%) (p<.0001). The agreement between the dominant VA and the larger side of TF was almost perfect (Kappa=0.087, p<.0001). ConclusionsThere was strong correlation between TF diameters and VA blood volume. Our results suggest that TF diameter of C6 level can be used to predict the side of the dominant VA reliably.

Posterior transodontoid fixation: A new fixation (Kotil) technique

Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique), through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA) side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT) of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left) side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw) medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw) fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an alternative new technique among the previously defined C1-C2 fixation techniques in eligible cases.

Basılar artery angulatıon and vertıgo due to the hemodynamıc effect of domınant vertebral artery

Vertebral arteries form the basilar artery at the pontobulbar junction. The vertebral artery may have dominancy in one of them. The branches of basilar arteries supply blood for the vestibular nuclei and its connections. Vertigo is seen generally in the upper middle aged patients. Vertigo can be observed in dolichoectasia of basilar artery such as angulation and elongation, because of the diminished blood supply and changed hemodynamic factors of vestibular nuclei and its connections. We hypothesized that angulation or elongation of basilar artery can be estimated according to the unilateral vertebral artery dominant hypertensive patients. The basilar artery can angulate from the dominant side of vertebral artery to the recessive side. These angulation and elongation can effect the hemodynamic factors in absence of growing collateral arteries. So, the vertigo attacks may occur in these patients.