Positional Vertebral Artery Occlusion Research Articles

Favorable Long-Term Outcomes for Positional Vertebral Artery Occlusion with Treatment Strategy Prioritizing Spinal Fusion Surgery.

Positional vertebral artery occlusion (PVAO) has a fundamental problem in the definition. We analyzed the long-term outcomes with a redefinition of the rare clinical entities as PVAO for a broader conceptualization, and discuss the efficacy of fusion surgery as a treatment option. We analyzed the clinical and radiologic characteristics and outcomes in 8 patients with PVAO who experienced cerebral ischemia during a 10-year period at our institution. The follow-up periods ranged from 60 to 132 months (mean, 93.5 months). All patients were initially treated conservatively with external fixation. If spinal instability was observed at the initial evaluation or a second stroke occurred during conservative treatment, cervical spinal fusion was performed with special consideration for vertebral artery dominance and the presence of its collateral flow regardless of the type of stroke. Conservative therapy was completed for 2 patients, and spinal fusion was performed for the other 6 patients. None of the patients experienced a recurrence of symptoms after discharge until the final follow-up visit, and the outcomes were excellent. Long-term functional outcomes were dependent on the patient's condition before the onset of stroke and the neurologic deficits resulting from the initial or recurrent stroke induced by embolism. We report our single-center experience with PVAO in which 75% of patients had embolic stroke. Because embolic stroke may have a greater risk of recurrence affecting the long-term outcomes, it should be prevented. In addition, if surgical intervention is necessary, spinal fusion surgery may be an effective option.

Duplex Ultrasonography-Detected Positional Vertebral Artery Occlusion in Upper Cervical Rheumatoid Arthritis.

Prospective imaging study. To clarify the frequency of positional vertebral artery (VA) occlusion using duplex ultrasonography in patients with rheumatoid arthritis (RA). Some patients with upper cervical RA develop thromboembolic stroke related to positional and transient VA occlusions; however, whether RA patients have positional VA occlusion without neurological symptoms is unclear. Outpatients with RA were enrolled. Clinical data were collected, and radiograph examinations were performed to measure the anterior atlantodental interval (AADI), the posterior atlantodental interval (PADI), and the Ranawat method. Patients underwent duplex ultrasonography during rotation to the contralateral side of the examination side, flexion, and extension of their neck. If positional VA occlusion was detected, CT angiography was conducted in the neutral position and in the same position that showed VA occlusion on duplex ultrasonography. Clinical and radiological data were compared between the VA occlusion (VAO) group and the non-VAO group. Sensitivity-specificity curve analyses were performed to clarify optimal threshold values of AADI, PADI, and the Ranawat method for predicting positional VA occlusion. Of the 132 RA patients, dynamic duplex ultrasonography showed positional VA occlusion in eight (6%) patients. Patients in the VAO group had a greater AADI (median, 7.4 vs. 2.3 mm; P < 0.001), a shorter PADI (median, 13.7 vs. 19.6 mm; P = 0.002), and a lower Ranawat value (median, 13.7 vs. 16.8 mm; P = 0.006) than those in the non-VAO group. Cut-off values of AADI, PADI, and the Ranawat method for predicting positional VA occlusion were 6.5, 14.0, and 15.5 mm, respectively. A subset of RA patients developed positional VA occlusion associated with cervical spine involvement.

Positional occlusion of the vertebral artery in a case of rheumatoid atlantoaxial subluxation presenting with multiple cerebral and cerebellar infarction

We report an uncommon case of positional occlusion of the vertebral artery associated with rheumatoid arthritis (RA). Plain radiography showed reducible atlantoaxial subluxation, and dynamic vertebral arteriography demonstrated positional occlusion of the left vertebral artery. The patient was treated with C1-2 posterior fusion and has since experienced no recurrent symptoms. Insufficiency of the vertebrobasilar artery is a relatively uncommon complication with cervical lesions in RA patients. However, when RA patients manifest recurrent cerebral and cerebellar symptoms, this condition should be kept in mind and actions taken to avoid further irreversible cerebral damage. Recommended imaging methods include vertebral dynamic lateral plain radiography of the cervical spine and vertebral arteriography at multiple cervical positions.

Doppler Ultrasonography and Computed Tomography Angiography Demonstrate Positional Occlusion of Vertebral Artery Associated With One-Sided Destruction of the Atlantoaxial Lateral Mass Caused by Rheumatoid Arthritis

Case report of a patient with rheumatoid arthritis (RA) and a positional occlusion of the left vertebral artery (VA). To describe the utility of Doppler ultrasonography and computed tomography (CT) angiography for the diagnosis of positional VA occlusion. In previous reports of positional VA occlusion in RA, angiography has been used for the diagnosis. However, it is difficult to demonstrate the three-dimensional relationship between the arteries and the bone structure with angiography. An 83-year-old man with a 20-year history of RA complained of severe vertigo when he leaned his head in the left-anterior direction. CT angiography in the neutral position revealed that the left VA was pinched between the posterior rim of the transverse foramen of C1 and the transverse process of C2. Doppler ultrasonography demonstrated positional VA occlusion and a severe reduction in blood flow at the position that most readily induces vertigo. Because the space between the transverse foramens of left C1 and C2 was reduced with the destruction of the left C1/C2 lateral masses, slight rotation, and anterior shift of C1 led to the occlusion of the VA. After posterior O-C2 fusion at the reduced position, the VA occlusion and vertigo disappeared. Doppler ultrasonography and CT angiography allow valuable measurements in the diagnosis of positional VA occlusion. The one-sided destruction of the C1/C2 lateral masses might be a causal factor for VA occlusion in RA. This is the first report of a new pathomechanism underlying positional VA occlusion demonstrated with three-dimensional CT angiography.

Subaxial Positional Vertebral Artery Occlusion Corrected by Decompression and Fusion

A rare case of subaxial vertebral artery (VA) positional occlusion is reviewed and treatment methods discussed. The decision process involved in treating subaxial VA positional occlusion is reviewed. Bow Hunter stroke is a symptomatic vertebrobasilar insufficiency caused by stenosis or occlusion of the VA with physiologic head rotation. It most commonly occurs at the junction of C1 and C2 and less commonly as the VA enters the C6 transverse foramen. Rotational stenosis of the VA is quite rare during its passage through the foramen transversarium of C3-C6. A 48-year-old gentleman presented describing syncopal episodes when he turns his head to the left side. Imaging revealed a congenitally narrowed right foramen transversarium and high-grade stenosis of the left VA when the head was turned to the left. A routine anterior cervical discectomy and fusion was performed with the addition of decompression of the left transverse foramen. Vascular imaging should be performed with the patient's head in both the neutral position and in the symptomatic position. Surgical treatment may be chosen if conservative therapies fail and generally has 1 of 2 goals-decompression of the VA or elimination of rotational movement at the affected level. Decisions between anterior and posterior decompressions may be influenced by the surgeon's comfort level with the approach and if the transverse foramen stenosis is caused mainly by an anterior (osteophytes at the uncinate process) or posterior (facet joint hypertrophy) process. The patient remains symptom-free after treatment. This report demonstrates the condition in the subaxial spine and describes successful treatment by fusion of the affected level combined with decompression of the foramen transversarium-a combination of previously described therapies.