Atlas posterior arch and vertebral artery's groove variants: a classification, morphometric study, clinical and surgical implications.

BACKGROUND: The third part of the vertebral artery (VA) coursing in vertebral artery groove (VAG) may be injured during posterior craniocervical junction approaches. OBJECTIVE: The current study classifies all possible variants of the posterior arch (PA) of the atlas vertebra (C1), focusing on VAG and calculates their incidence. PA and VAG morphometry is studied in correlation with gender and age. Clinical and surgical implications of recorded variants are provided in an effort to explain associated pathology. The usefulness of three-dimensional computed tomography (3D-CT) in detecting PA variants is highlighted. MATERIALS AND METHODS: Two hundred and forty-four Greek adult dry C1 were classified in types according to PA morphology [i.e. presence of an imprint or a distinct VAG and occurrence of a partially or completely ossified dorsal (PDP or CDP) or lateral (PLP or CLP) ponticle unilaterally or bilaterally]. Combined variants were also included. RESULTS: A VAG and an imprint were detected in 42.62% and 15.16%. A PDP and CDP were observed in 18.03% and 15.98%, while a CLP and PLP in 2.05% and 1.64%, respectively. Combined PDP and PLP were detected in 2.05%, a CDP and CLP similarly to a CDP and PLP in 1.23% and a PDP and CLP in 0.40%. CONCLUSIONS: Variants' classification will contribute to an in depth understanding of the complex C1 anatomy and may explain cases of VA entrapment and injury during PA fixation. Surgeons should carefully study 3D-CT imaging to ensure type, location, size and shape of C1 ponticles in combination with VAG morphology and VA course before screw insertion.

[Endovascular interventions for stenoses and occlusions of the brachiocephalic trunk]. / Éndovaskuliarnye vmeshatel'stva pri stenozakh i okkliuziiakh brakhiotsefal'nogo stvola.

The study was undertaken to evaluate the efficacy and safety of endovascular interventions in the treatment of stenoses and occlusions of the brachiocephalic trunk (BCT). Described in the article are the results of retrospectively analysing the efficacy of endovascular interventions performed in a total of forty-five patients presenting with lesions of the BCT. Depending on the type of the BCT lesion, the patients were divided into 2 groups: Group One consisted of 28 patients diagnosed with stenoses of the BCT and Group Two included 17 patients found to have occlusions of the BCT. The outcomes of the interventions were assessed with due regard for the findings obtained by angiography, ultrasonographic duplex scanning of the brachiocephalic vessels, as well as by the examination of the patient's neurological status. The remote results were evaluated at follow-up terms ranging from 6 months to 4 years. No ischaemic strokes, myocardial infarctions, nor lethal outcomes were observed during 30 days after the intervention. In the early postoperative period, there occurred 1 (3.6%) case of transitory ischaemic attack in Group One, with also 1 (5.9%) case thereof encountered in Group Two. Within the time frame of the follow-up period (48 months), recurrent occlusion of the stented segment of the BCT was registered in 2 (7.1%) patients from Group One and in 1 (5.8%) patient from Group Two (p=0.87). The primary patency rate at 4 years in Group One and Group Two patients amounted to 86.8 and 88.3%, respectively (p=0.84). A conclusion thus drawn was as follows: endovascular intervention for stenoses and occlusions of the BCT is an effective and safe method of preventing acute cerebral circulation impairments in the vertebrobasilar basin.

Argatroban for preventing occlusion and restenosis after extracranial artery stenting.

BACKGROUND/AIMS: Restenosis following extracranial artery stenting is a limitation that affects long-term outcomes. Effective and satisfying pharmacological strategies in preventing restenosis have not been established. This study aimed to evaluate whether argatroban, a direct thrombin inhibitor, could reduce the risk of in-stent restenosis after extracranial artery stenting. METHODS: One hundred and fourteen patients hospitalized between August 2010 and August 2011 were enrolled. Patients were randomly assigned to argatroban (n = 58) and blank control groups (n = 56). The patients in the argatroban arm were treated with 10 mg of intravenous argatroban twice daily 2 days before and 3 days after the stenting procedures. Patients were followed for 12 months after the procedure. During follow-up, restenosis and target revascularization were analyzed. Recurrent cerebrovascular and cardiovascular events and deaths were also compared between the groups. RESULTS: One patient in the stenting group withdrew immediately after the procedure due to unsuccessful stenting. Restenosis occurred in 4 patients (7.4%) in the argatroban group and in 11 patients (21.6%) in the control group during the 6- to 9-month angiographic follow-up period (p = 0.032). Nine months after the procedures, argatroban-treated patients had a trend towards a lower incidence of target revascularization compared with the controls (5.4 vs. 13.7%, p = 0.188). No major bleeding events or other adverse events occurred in the argatroban group. CONCLUSION: This pilot clinical trial is the first that uses argatroban to prevent restenosis in ischemic cerebrovascular disease, and suggests that intravenous administration of argatroban is effective and safe in preventing restenosis after extracranial artery stenting. Larger randomized controlled clinical trials are warranted.

Treatment of posterior circulation stroke: Acute management and secondary prevention.

One-fifth of strokes occur in the territory of the posterior circulation, but their management, particularly acute reperfusion therapy and neurointervention procedures for secondary prevention, has received much less attention than similar interventions for the anterior circulation. In this review, we overview the treatment of posterior circulation stroke, including both interventions in the acute setting and secondary prevention. We focus on areas in which the management of posterior circulation stroke differs from that of stroke in general and highlight recent advances.Effectiveness of acute revascularization of posterior circulation strokes remains in large parts unproven. Thrombolysis seems to have similar benefits and lower hemorrhage risks than in the anterior circulation. The recent ATTENTION and BAOCHE trials have demonstrated that thrombectomy benefits strokes with basilar artery occlusion, but its effect on other posterior occlusion sites remains uncertain. Ischemic and hemorrhagic space-occupying cerebellar strokes can benefit from decompressive craniectomy.Secondary prevention of posterior circulation strokes includes aggressive treatment of cerebrovascular risk factors with both drugs and lifestyle interventions and short-term dual anti-platelet therapy. Randomized controlled trial (RCT) data suggest basilar artery stenosis is better treated with medical therapy than stenting, which has a high peri-procedural risk. Limited data from RCTs in stenting for vertebral stenosis suggest that intracranial stenosis is currently best treated with medical therapy alone; the situation for extracranial stenosis is less clear where stenting for symptomatic stenosis is an option, particularly for recurrent symptoms; larger RCTs are required in this area.

Anesthetic implications for the patient with osteogenesis imperfecta.

Osteogenesis imperfecta is an inherited disorder of the connective tissue stemming from gross abnormalities in collagen formation and structure. Affected patients fall into 4 classifications each displaying the similar properties of easily fractured bones, hypermobile joints, blue or gray sclera, skeletal deformities, and fragile skin. More severe forms of the disease may manifest platelet dysfunction, cardiac anomalies, hypermetabolic syndromes, respiratory compromise, and/or basilar invagination. Treatment of osteogenesis imperfecta is mainly supportive, consisting of prompt surgical treatment of fractures to prevent deformity and maintaining mobility to lessen the chance of pulmonary or cardiovascular complications. These treatment modalities make anesthesia of paramount importance. Current literature exposes many potential anesthetic complications associated with osteogenesis imperfecta. The research shows that implications range from simply positioning the patient on the operating room table to management of rare occurrences such as malignant hyperthermia and basilar invagination. Commonly encountered complications include a difficult airway, intraoperative bleeding due to platelet dysfunction, respiratory compromise due to skeletal deformity, and congenital cardiac anomalies. Proper preparation and preoperative assessment is important, as is the choice of anesthetic technique. Correct identification of risk factors and optimization of health before surgery should lead to an uneventful anesthetic course.

Vertebrobasilar stenosis predicts high early recurrent stroke risk in posterior circulation stroke and TIA.

BACKGROUND AND PURPOSE: 20% of ischemic stroke is in the posterior circulation, but there is little prospective data on early recurrent stroke risk and whether vertebrobasilar stenosis predicts a high recurrence risk. This natural history data are important as it is technically possible to stent such lesions. Contrast enhanced MRA (CE-MRA) and CT angiography (CTA) now allow noninvasive identification of vertebrobasilar stenosis. METHODS: 216 consecutive patients presenting with posterior circulation TIA or stroke were recruited and prospectively followed for 90 days. 8 patients with vertebral dissection were excluded. CE-MRA or CTA at presentation and 90-day follow-up was available in 182. Any posterior circulation TIA/stroke in the month before the presenting episode was recorded. RESULTS: Taking the first event (including TIA/stroke in the previous month) as the index case recurrent stroke risk in patients with stenosis was 30.5% versus 8.9% in those without; RR 3.4 (95% CI 1.7 to 7.0), P<0.001). Taking the presenting episode as the index case the risk was 13.8% versus 4.1%; RR 3.4 (95% CI 1.1 to 10.5) P=0.0274. The probability of recurrence was highest soon after the initial event. CONCLUSIONS: The presence of vertebro-basilar stenosis identifies a group of patients with posterior circulation stroke who have a high early recurrent stroke risk. Early intervention might reduce recurrent stroke risk. Vertebral stenosis can now be treated by stenting, but determining whether this reduces the early stoke risk requires randomized controlled trials.

Basilar artery dissection treated by Neuroform stenting: fungal stent infection.

BACKGROUND: The authors describe a case of basilar artery dissection treated with Neuroform stenting. This new treatment modality for basilar artery dissection may be safer than anticoagulation in patients with subarachnoid hemorrhage. However, complications associated with stenting should be taken into careful consideration. These complications include thromboembolism and stent infection. CASE DESCRIPTION: This 36-year-old white male underwent Neuroform stenting of basilar artery dissection and subsequently developed bilateral pontine infarct and fungal stent infection. This is worrisome in an otherwise healthy 36-year-old. Thromboembolism is a well-known phenomenon with endovascular stenting that may be improved with evolution in stent technology. Fungal infection of Neuroform stent in a patient with no history of immunocompromised status is of major concern. The patient subsequently underwent successful treatment of stent infection through parenteral antifungal agent. CONCLUSIONS: This case report highlights the potential pitfalls of Neuroform stenting of basilar artery dissection and potential methods by which to avert these complications. Further evolution in stent technology may help prevent further complications involving Neuroform stenting of basilar artery dissection. In addition, the successful treatment of stent infection through parenteral agent demonstrates the increasing efficacy of novel antifungal agent in the treatment of these infections.

Carotid endarterectomy for internal carotid artery stenosis associated with persistent primitive hypoglossal artery: efficacy of intraoperative multi-modality monitoring.

INTRODUCTION: A persistent primitive hypoglossal artery (PPHA) is a rare vascular anomaly and is usually asymptomatic. However, the PPHA may cause multi-territorial infarction when complicated by internal carotid artery (ICA) stenosis. CASE REPORT: We describe a 73-year-old male who simultaneously developed cerebral infarction in both carotid and vertebrobasilar territories due to ICA stenosis associated with an ipsilateral PPHA. The PPHA mainly provided blood flow to the vertebrobasilar territory in this case, because the bilateral vertebral arteries were markedly hypoplastic. He underwent carotid endarterectomy under internal shunting. Intraoperative multi-modality monitoring including angiography, motor evoked potential, and near infrared spectroscopy was very useful to avoid ischemic complications during surgery. The postoperative course was uneventful. CONCLUSION: It should be reminded that a persistent carotid-basilar anastomosis can cause multi-territorial cerebral infarction mimicking cardiogenic embolism and may be a candidate for aggressive prophylactic intervention, when occlusive lesions develop in the carotid artery. It is very important to monitor hemodynamic and/or electrophysiological status in both carotid and vertebrobasilar territories in order to perform carotid endarterectomy safely in such cases.

Doppler insonation of vertebral artery blood flow changes associated with cervical spine rotation: Implications for manual therapists.

The controversy related to changes in vertebral artery (VA) blood flow associated with rotation of the cervical spine and the implications for professional practice is still of concern to manual therapists. The aim of this review of the literature is, first, to assess current evidence of altered VA blood flow following cervical spine rotation in persons with and without signs and symptoms of vertebrobasilar ischemia/insufficiency (VBI). Second, any reported, related alterations in blood flow that may have consequences for the individual will be discussed to assist manual therapists in pretreatment risk assessment of patients. The most commonly used noninvasive, in vivo technique for measuring blood flow is Doppler ultrasonography. Of the 88 relevant papers retrieved by a systematic literature search covering the past 50 years, 20 studies reported measurement of VA blood flow related to cervical spine rotation. A critical analysis of these reports revealed that there is no standardization of methods used (heterogeneous samples, small sample sizes, various measurement positions and instruments, and different parts of the VA measured); no consensus of findings (no change, and a significant reduction in contralateral VA blood flow, with or without VBI); and no correlations found between rotation, blood flow, and VBI. Nevertheless, this review is of value in increasing our knowledge of the possible mechanisms and consequences of repeated minor arterial trauma and of blood flow changes related to rotational movements used in cervical manual therapy. It highlights, too, the need for caution in the interpretation of pretreatment risk assessment outcome measures.

Safety, feasibility, and short-term follow-up of drug-eluting stent placement in the intracranial and extracranial circulation.

BACKGROUND AND PURPOSE: The use of bare metal stents to treat symptomatic intracranial stenosis may be associated with significant restenosis rates. The advent of drug-eluting stents (DESs) in the coronary circulation has resulted in a reduction of restenosis rates. We report our technical success rate and short-term restenosis rates after stenting with DESs in the intracranial and extracranial circulation. METHODS: This study was a retrospective review of the period between April 1, 2004, and April 15, 2006, of 59 patients with 62 symptomatic intracranial or extracranial atherosclerotic lesions at 2 medical centers (University of Pittsburgh and Borgess Medical Center). RESULTS: The mean age of our cohort was 61+/-12 years. The location of the 62 lesions was as follows: extracranial vertebral artery 31 (50%), intracranial vertebral artery or basilar artery 18 (29%), extracranial internal carotid artery (ICA) near the petrous bone 5 (8%), and intracranial ICA 8 (13%). There were 2 (3%) periprocedural complications: 1 non-flow-limiting dissection and 1 disabling stroke. Fifty vessels were available for follow-up angiography or computed tomography angiography at a median time of 4.0+/-2 months. A total of 2 of 36 extracranial stents (7%) and 1 of 26 intracranial stents (5%) were found to have restenosis > or = 50% at follow-up. CONCLUSIONS: This report demonstrates that DES delivery in the intracranial and extracranial circulation is technically feasible. A small percentage of patients developed short-term in-stent restenosis. Longer-term follow-up is required in the setting of a prospective study to determine the late restenosis rates for DESs in comparison with bare metal stents.

Transarterial coil embolization of a high-flow vertebrojugular fistula due to penetrating craniocervical trauma: case report.

BACKGROUND: Vertebrojugular fistulas after penetrating cervical trauma (gunshot or stab wounds) are rarely reported. Successful endovascular coil embolization of an acute fistulizing vertebral artery pseudoaneurysm involving an obstructed internal jugular vein is presented and the various treatment strategies for such a lesion are described. CASE DESCRIPTION: A 23-year-old man presented from an outside institution after sustaining 2 gunshot wounds in a civilian conflict. Neuroimaging revealed a right vertebral artery pseudoaneurysm, which formed a fistulous connection with the internal jugular vein. Because venous outflow obstruction was present just below the fistula, a high-flow shunt was directed intracranially. Both the pseudoaneurysm and arteriovenous fistula were accessed percutaneously via a transfemoral route and coil embolization was performed. Perfusion of the basilar artery circulation was assumed by the contralateral vertebral artery. The ipsilateral posteroinferior cerebellar artery filled through retrograde flow down the vertebral confluence. CONCLUSIONS: Coil embolization is a safe and reliable strategy by which to obliterate an acute traumatic vertebrojugular fistula as well as pseudoaneurysm. Serial angiographic follow-up is mandatory to document a persistent cure.

Iatrogenic vertebrobasilar insufficiency after surgery of the subclavian or brachial artery: review of three cases.

OBJECTIVE AND IMPORTANCE: Vertebrobasilar insufficiency resulting from disease of the subclavian artery is well recognized. Usually, this occurs as the "subclavian steal" syndrome in the context of chronic subclavian stenosis and is consequently well tolerated because of collateralization. Acute disruption of the hemodynamics of the aortic arch vessels, however, can produce disastrous sequelae. CLINICAL PRESENTATION: We present three cases of iatrogenic vertebrobasilar insufficiency sustained as complications of surgery of the left subclavian artery or its distal continuation. The cases were chosen from a review of approximately 400 emergency neurosurgery consultations requested at the Los Angeles County Hospital between November 1995 and February 1996. INTERVENTION: The first patient underwent repair of a traumatic brachial artery occlusion and awoke postoperatively with bilateral cortical blindness, right hemiparesis, and multiple cranial nerve deficits that were most likely caused by acute subclavian steal. The second underwent removal of a subclavian embolus and developed bilateral cerebellar infarction leading to persistent coma, possibly from inadvertent embolization of the vertebral artery during surgery. The third underwent resection and bypass grafting of a subclavian aneurysm. Good backflow was reported when the vertebral artery was disarticulated from the subclavian artery, and this vessel was not reimplanted into the graft. The patient suffered massive cerebellar infarction leading rapidly to brain death. CONCLUSION: There are myriad ways in which the inherent redundancy of the vertebrobasilar system may be jeopardized, and when this protective mechanism fails, the results can be disastrous. Flow through the vertebral arteries may be compromised by thrombosis, embolization, dissection, inappropriate ligation, excessive head rotation, hypotension, vasospasm, or acute subclavian steal. These examples illustrate the importance of understanding the complex physiology of posterior fossa circulation as the basis of pre-, intra-, and postoperative management of patients undergoing surgery of the subclavian artery.

[Prevention of cerebral complications during thoracic aortic aneurysms operation: study of preoperative selective cerebral arteriography].

Preoperative selective cerebral arteriography is carried out in order to determine if the circle of Willis is intact in the cases of the thoracic aortic aneurysms. As regard to the bilateral vertebrobasilar communications, 26 of 30 patients (86.7%) have good condition, 4 of 30 patients (13.3%) have poor, and in 2 cases the left vertebral artery supplied broad area of posterior cranial fossa. We believe that in the cases in whom the left vertebral artery is dominant, and cross collateral circulation is absent, perfusion of the left subclavian artery is necessary to prevent vertebrobasilar ischemia during aortic aneurysms operation under normothermia.

[Early manifestation and dynamics of the development of vertebrobasilar circulation disorder associated with cervicovertebral dysfunction, directions of the prophylaxis and treatment]. / Ranni proiavy i dynamika rozvytku vertebral'no-bazyliarnoï dystsyrkuliatsiï, pov'iazanoï z tservikovertebrohennoiu dysfunktsiieiu, ta napriamy ïï profilaktyky i likuvannia.

206 children and young patients have been observed to diagnose the origin and dynamics of the development of vertebrobasilar circulation disturbances. The great importance was given to detail data collection by questionnairing and studying outpatient medical records of the patients since early childhood. The obtained data were compared with those of healthy people of similar age. Risk factors and the development of symptoms of the disease with age were analyzed in the article. Genetical and constitutional factors are of great importance in the development of vascular and musculoskeletal systems pathologies. The intensity of the pathologic process and dynamics of its development connected directly with the number and pathologic factors duration. Early manifestation of vertebrobasilar disturbances is considered in practice as vegetovascular dystonia. Taking into account a reflex factor in the development of the pathology, reflex therapeutic methods will be pathogenetically justified.

Restenosis rates following vertebral artery origin stenting: does stent type make a difference?

OBJECTIVES: To compare our experience with sirolimus and paclitaxel-eluting stents (drug-eluting stents [DES]) and non-drug-eluting stents (NDES) for treatment of vertebral artery (VA) origin stenosis and review the literature. METHODS: A retrospective review of our prospectively collected database was performed. Clinical and radiologic follow up was obtained by reviewing office records and radiology. Data collected included demographics, comorbidities, presenting symptoms, stenosis severity, contralateral VA stenosis and/or carotid stenosis, type of stent used, angioplasty before or after stenting, post-treatment residual stenosis, clinical and radiological follow up and retreatment. Patients with symptomatic > 60% stenosis or asymptomatic > 70% stenosis and/or a hypoplastic or occluded contralateral VA or significant carotid occlusion were chosen for revascularization. RESULTS: Thirty-five patients treated with NDES and 15 treated with DES for management of VA origin stenosis were identified. The technical success rate of the procedure was 100%. There were no procedural complications. There were 7 asymptomatic patients (NDES Group-4, DES Group-3). In the NDES Group, 9 patients had pre-stent angioplasty; 2 had post-stent angioplasty. In the DES group, 4 patients had post-stent angioplasty. Symptoms resolved in 30/31 (96.8%) patients treated with NDES and 11/12 (91.7%) treated with DES. Thirty-six patients had radiologic follow up (median 21.3 months); in-stent restenosis was documented in 11 patients (NDES 9/24 [38%], DES 2/12 [17%]). Among patients receiving NDES, re-stenotic lesions required angioplasty in 7 patients. No patients in the DES group required angioplasty. CONCLUSIONS: DES for treatment of VA origin stenosis may decrease the incidence of restenosis when compared to NDES. Validation in prospective, randomized, multicenter trials is necessary.

Delayed thrombosis of the basilar artery after stenting for a basilar trunk dissection aneurysm. A case report and review of the literature.

A 30-year-old man was referred in our department for treatment of a midbasilar trunk aneurysm. His presenting symptoms included headache and dizziness. A CT scan at another hospital showed no significant findings whereas a digital subtraction angiogram disclosed a dissecting aneurysm in the midbasilar trunk, and there was severe stenosis in the basilar artery. After discussion, we planned to use stent-assisted-coil embolization technique. During the procedure, a LEO stent (Balt, Montmorency, France) was implanted into the basilar artery across the aneurysm neck, but fearing acute basilar artery occlusion because of stent collapse or thrombus we did not fill coils into the aneurysm. After the procedure, the completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. The patient awoke from general anaesthesia after the procedure and had no additional neurological symptoms, he was discharged three days later and used clopidogrel and aspirin for antiplatelet therapy. Six months later when he was admitted for a recheck, a DSA showed the basilar artery was occluded completely and the aneurysm had disappeared even though the patient remained neurologically normal.

Less-invasive management of left subclavian artery in stent-grafting for distal aortic arch disease.

Simple coverage of the left subclavian artery (LSA) in thoracic endovascular aortic repair (TEVAR) is still a controversial procedure. We present our modified strategy dealing with LSA in TEVAR. Hand-made stent grafts were placed more proximal beyond the LSA for 104 patients. In elective 76, preoperative LSA occlusion test was performed on 31 patients, and preoperative computed tomographic angiography (CTA) of the vertebro-basilar artery was performed on the remaining 45. Head vessels were planned to be kept patent using fenestrated stent grafts, if possible. Stent grafts were placed from zone 0 in 23, zone 1 in 39, and zone 2 in 42. The LSA occlusion tests revealed harmful effects, such as loss of consciousness and vertigo in two out of 31 patients (6.5%). Vertebro-basilar arterial CTA revealed possible risks, if LSA covered, in three out of 45 patients (6.7%). Fenestrated stent grafts could successfully preserve 131 head vessels, except for one unintentional occlusion of the left carotid artery (0.75%). There was no LSA-related complication in any of the cases. A combination of preoperative vertebro-basilar arterial CTA and fenestrated stent grafts is useful to avoid possible LSA-related complications in TEVAR.

Atherosclerosis in the vertebral artery: an intrinsic risk factor in the use of spinal manipulation?

The presence of atherosclerotic plaques and their influence on the vertebral artery is of clinical importance within the scope of spinal manipulation. Manipulation may stimulate the development of atherosclerotic plaques, could detach an embolus with ensuing infarction, injure the endothelium or may directly cause a dissection in the presence of atherosclerotic plaques. In order to identify the sites and frequency of atherosclerotic plaques and to determine its relation to the tortuous course of the vertebral artery, a cadaveric study was performed. The vertebral arteries of 57 human cadavers were studied. The vertebral artery was virtually divided into four segments: the pre-vertebral (V1), the vertebral (V2), the atlanto-axial (V3), and the intracranial segment (V4). Abnormalities in the origin and course of the vertebral artery were noted, along with any associated osseous, or cartilaginous anomalies in the neck. After dissection, the artery was opened and macroscopically screened for the presence of atherosclerotic plaques. In 22.8% of the cases, no atherosclerotic plaques were present. In 35.1% of the cases, the atherosclerotic plaques were unilateral, of which 60.0% was on the left side, 40.0% on the right side, and in 42.1%, the occurrence was bilateral. Atherosclerotic plaques were significantly more present in the V3 segment than in the V1 (0.007) and V2 segment (0.049). In the V1 (P=0.008) and V2 segment (P=0.002), there was a correlation between a tortuous course of the vessel and the occurrence of atherosclerotic plaques. In individuals with marked atherosclerotic disease, stretching and compression effects of rotational manipulative techniques on atherosclerotic vessels impose a further risk factor for vertebrobasilar insufficiency. As direct evidence of atherosclerotic plaques are rarely available, therapists should avoid manipulative techniques at all levels of the cervical spine in the presence of any indirect sign of atherosclerotic disease or in the presence of calcified arterial walls or tortuosities of the vessels visible on routinely available X-ray images of the cervical or thoracic spine. It is strongly recommended, that if any doubt exists about the nature of a clinical presentation, vigorous manual procedures should be avoided until either the diagnosis is definitive or gentle manual therapy has proven effective.