An unusual artery causing an unusual stroke.

Bilateral thalamic infarctions are uncommon and often lead to more severe and long-lasting symptoms than unilateral thalamic infarctions. This article describes a patient with bilateral thalamic infarction caused by occlusion in the artery of Percheron, an anatomic variant thought to be present in 4% to 12% of the population.

Viral Coagulopathy in Patients With COVID-19: Treatment and Care.

COVID-19 has proven to be particularly challenging given the complex pathogenesis of SARS-CoV-2. Early data have demonstrated how the host response to this novel coronavirus leads to the proliferation of pro-inflammatory cytokines, massive endothelial damage, and generalized vascular manifestations. While SARS-CoV-2 primarily targets the upper and lower respiratory tract, other organ systems are also affected. SARS-CoV-2 relies on 2 host cell receptors for successful attachment: angiotensin-converting enzyme 2 and transmembrane protease serine 2. Clinicopathologic reports have demonstrated associations between severe COVID-19 and viral coagulopathy, resulting in pulmonary embolism; venous, arterial, and microvascular thrombosis; lung endothelial injury; and associated thrombotic complications leading to acute respiratory distress syndrome. Viral coagulopathy is not novel given similar observations with SARS classic, including the consumption of platelets, generation of thrombin, and increased fibrin degradation product exhibiting overt disseminated intravascular coagulation-like syndrome. The specific mechanism(s) behind the thrombotic complications in COVID-19 patients has yet to be fully understood. Parenteral anticoagulants, such as heparin and low-molecular-weights heparins, are widely used in the management of COVID-19 patients. Beyond the primary (anticoagulant) effects of these agents, they may exhibit antiviral, anti-inflammatory, and cytoprotective effects. Direct oral anticoagulants and antiplatelet agents are also useful in the management of these patients. Tissue plasminogen activator and other fibrinolytic modalities may also be helpful in the overall management. Catheter-directed thrombolysis can be used in patients developing pulmonary embolism. Further investigations are required to understand the molecular and cellular mechanisms involved in the pathogenesis of COVID-19-associated thrombotic complications.

Fufang-Zhenzhu-Tiaozhi capsule ameliorates rabbit's iliac artery restenosis by regulating adiponectin signaling pathway.

BACKGROUND AND PURPOSE: Fufang-Zhenzhu-Tiaozhi Capsule (FTZ), a traditional Chinese medicine, has been shown obvious effects on the treatment of dyslipidemia and atherosclerosis. The aim of this study was to evaluate whether FTZ can ameliorate rabbit iliac artery restenosis after angioplasty by regulating adiponectin signaling pathway. EXPERIMENTAL APPROACH: The rabbit iliac artery restenosis model was established through percutaneous iliac artery transluminal balloon angioplasty and a high-fat diet. Twenty eight male New Zealand rabbits (8-week-old) were divided into sham operation group (Group Ⅰ), model group (Group Ⅱ), atorvastatin group (Group Ⅲ) and FTZ group (Group Ⅳ), with 7 rabbits in each group. Vascular stenosis was analyzed with Digital Subtraction Angiography. Level of adiponectin (APN), and inflammatory factor including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) as well as monocyte chemoattractant protein-1 (MCP-1) was measured by Enzyme Linked Immunosorbent Assay; and injured iliac artery was collected for Hematoxylin-eosin staining and Western Blotting detection of expression of peroxisome proliferator-activated receptor-alpha (PPAR-α), adenosine 5'-monophosphate -activated protein kinase (AMPK) and phosphorylated adenosine 5'-monophosphate -activated protein kinase (p-AMPK). Besides, we evaluated FTZ's safety for the first time. KEY RESULTS: Percutaneous iliac artery transluminal balloon angioplasty and high-fat diet result in inflammatory response and restenosis. Compared with Group Ⅱ, iliac artery restenosis was significantly ameliorated in Group Ⅳ (P < 0.05). Treated with FTZ, serum lipids were significantly decreased (P < 0.01), while the level of APN was elevated significantly (P < 0.01). Western blotting detection of the injured iliac artery showed that the expressions of PPAR-α, AMPK and p-AMPK were significantly increased in Group Ⅳ (P < 0.01) than that in Group Ⅱ. Besides, before and after taking drugs, liver and kidney function indicators, creatine kinase, as well as measurement of echocardiography were of no statistical difference in four groups(P > 0.05). CONCLUSIONS AND IMPLICATIONS: FTZ could effectively reduce serum lipids and ameliorate rabbit's iliac artery restenosis after angioplasty, and its mechanism may be related to activation of APN signaling pathway.

Use of Embolectomy With Local Anesthesia for Anticoagulation Failure in Radial Artery Thrombosis.

OBJECTIVE: Although prevention of radial artery thrombosis and cardiac complications after interventions using radial access is well investigated, there is yet no clinical study that completely evaluated access-related complications. However, there is still no consensus on what exact treatment should be used in these patients. In clinical practice, analgesic, anticoagulant, and antiplatelet treatments usually improve symptoms in patients with pain; however, in some patients, complaints may persist and may not respond to these treatments. In these patients, low-risk embolectomy with a small skin incision may be beneficial. METHODS: A total of 102 patients with radial artery thrombosis after cardiac catheterization were included in the study between 2016 March and 2018 December. After the patients' initial evaluation, anticoagulation with enoxaparin or tinzaparin and antiplatelet therapy with acetylsalicylic acid and oral/local analgesic/anti-inflammatory and local anesthetic therapy were administered for 1 month. Patients whose symptoms resolved after medical treatment were followed up as outpatients. Embolectomy was performed in consenting patients who did not respond to the medical treatment. RESULTS: Of 102 patients included in the study, 33 underwent embolectomy, whereas 69 received only medical treatment. None of the patients experienced any complications, morbidity, or mortality in the peroperative period and during the medical treatment. The pretreatment symptom scores of patients who actively use their hands in daily life and profession were significantly higher than the scores of patients who are relatively less active (P = .013). Pretreatment symptom scores were negatively correlated with age (r = -0.584); symptom scores increased significantly with the decrease of patient age. No benefit from medical treatment and need for surgery was significantly greater in patients who are younger and use their hands actively in daily life and profession (P = .028). The decrease in symptom scores after treatment was significantly greater in the surgical group than in the medical group (P = .003). CONCLUSION: Radial access should be exercised with care in patients who may develop significant thrombosis-related complaints and it is necessary to decide whether radial access is essential. If patients have ongoing symptoms despite medical treatment, embolectomy can be considered as a treatment option.

Impact of hepatitis virus infection on arterial calcification among incident hemodialysis patients.

BACKGROUND: The impact of hepatitis virus infection on arterial calcification (AC) was not studied. OBJECTIVE: To study the prevalence, severity and distribution of AC in incident hemodialysis patients with hepatitis B and C viral infection. CASES AND METHODS: 172 stage 5 CKD adults (98 male and 74 female) were included; 58 of them were seronegative for both hepatitis B and C (SN group), 48 were positive for hepatitis B virus infection (HBV group) and 66 were hepatitis C virus positive (HCV group). Beside histopathology of the obtained arterial samples, all these cases were examined for body mass index (BMI), serum calcium (Ca), phosphorus (P), alkaline phosphatase (AP), serum albumin, uric acid (UA), alanine transaminase (ALT), parathormone (PTH), fibroblast growth factor 23(FGF23), interleukin 6 (IL6), and 25 hydroxy vitamin D (25 (OH) vit D), hemoglobin concentration, and serum ferritin. RESULTS: 86 (50%) of the cases had AC; 11 of them were in SN group (19%), 9 in HBV group (18.8%) and all the 66 HCV group (100%). In SN group, 4 had intimal calcification, 5 had medial calcification, and 2 had both intimal and medial calcification. In HBV group, 9 had intimal calcification, while no cases were encountered with either medial or both site calcifications. In HCV group, 16 had intimal calcification, 31 had medial calcification, and 19 had both intimal and medial calcification. Calcification was in the form of spots in one case in SN group, and 6 cases in HBV group, a single plaque of calcification in 5 cases of SN group, 3 cases of HBV group, and 16 cases of HCV group, multiple plaques were detected in 4 cases in SN group, and 31 cases in HCV group, and diffuse calcification in one case in SN group, and 19 cases in HCV group. In HBV group, calcification was only detected in patients with high viremia, while all patients with low or moderate viremia were devoid of calcification. In HCV group, all patients with low viremia had intimal solitary plaque of calcification, all patients with moderate viremia had multiple plaques of medial calcification, while all patients with high viremia had diffuse intimal and medial calcification. Both groups of viral hepatitis were significantly different in comparison to SN group in either distribution or calcification score (P<0.001 in all). HBV group had significantly lower serum P, CaxP and PTH in comparison to SN group (4.6±0.66 vs. 5.45±0.77mg/dL, 36.4±7.2 vs. 44.1±8.69, and 348±65.4 vs. 405.9±83.2pg/mL, P<0.001, <0.001, and 0.035 respectively). On the other hand, HCV group did not show any significant difference in any of the studied parameters compared to SN group. CONCLUSION: HCV positive patients are more prone to develop AC that is more extensive. HBV positive patients were less likely to have arterial medial calcification, probably related to lower serum phosphorus, CaxP product and PTH. HCV infection should be added as risk factor for AC among CKD patients. Further studies are needed to confirm these findings.

Diagnosis of hypothenar hammer syndrome in a patient with acute ulnar artery occlusion.

A 56-year-old truck driver with a history of tobacco use presented with acute onset digital ischaemia in the ulnar distribution of his dominant hand, associated with severe pain. Occupational exposures included extensive manual labour and prolonged vibratory stimuli. Workup with Doppler and angiography confirmed the diagnosis of hypothenar hammer syndrome (HHS). After the failure of medical management, he underwent ulnar artery thrombectomy with reconstruction and arterial bypass grafting. His pain improved significantly postsurgically, and he was able to return to a normal routine. This case illustrates the classic presentation, examination, imaging findings and management options of HHS. HHS should be considered in patients with digital ischaemia and associated occupational exposures. Diagnosing the condition appropriately allows for optimal management, aiming at minimising symptoms and maximising quality of life.

In vivo characterization of a new type of biodegradable starch microsphere for transarterial embolization.

Transarterial embolization is an established minimally invasive treatment for solid tumors. Unintended inflammation, foreign body reactions and ischemia-triggered neoangiogenesis are clinical drawbacks of permanent embolic materials. The aim of the current study was to characterize a new type of biodegradable starch microsphere with regard to angiographic and histopathological features such as patterns of acute arterial occlusion as well as induction of tissue necrosis, microsphere biodegradation, and inflammation and foreign body reactions during follow-up. Key characteristics of both biodegradable prototypes (L1 and L2; prototype groups) were as follows: microspheres are biodegradable by serum α-amylase, produced from chemically crosslinked potato starch to different extents, in a diameter range of ∼300-800 µm, differing in size distribution and featuring a microsphere deformation of ∼1%. In vivo transarterial embolization with L1 and L2, while applying clinical standard techniques, was performed and compared with clinically established permanent microspheres (Embosphere®500-700 and Embosphere®700-900; control groups). Twenty-four pig kidneys were embolized with the different embolic materials by following the study protocol, and there were no technical failures or complications. Parenchymal necrosis with interstitial calcification was observed in all kidneys independent of the type of embolic material used. Compared with the permanent embolic materials, biodegradable microspheres showed complete (L1) or partial (L2) biodegradation within one week after transarterial embolization, and induced a comparable (L1) or a lower (L2) degree of arterial wall necrosis and a lower degree of inflammation and foreign body reactions. In conclusion, the presented new type of biodegradable microsphere is promising, and could be further evaluated in terms of clinical translation.

Arteriopathy after transarterial chemo-lipiodolization for hepatocellular carcinoma.

OBJECTIVES: The purpose of this study was to investigate the incidence of and the risk factors for arteriopathy in hepatic arteries after transarterial chemo-lipiodolization in patients with hepatocellular carcinoma and the subsequent treatment strategy changes due to arteriopathy. PATIENTS AND METHODS: A total of 365 arteries in 167 patients (126 men and 41 women; mean age, 60.4±15.0 [SD] years [range: 18-87 years]) were evaluated for the development of arteriopathy after chemo-lipiodolization with epirubicin- or doxorubicin-Lipiodol® emulsion. The development of arteriopathy after chemo-lipiodolization was assessed on arteriograms performed during subsequent transarterial treatments. The treatment strategy changes due to arteriopathy, including change in the chemo-lipiodolization method and the application of alternative therapies was also investigated. Univariate and multivariate binary logistic regression models were used to identify risk factors for arteriopathy and subsequent treatment strategy change. RESULTS: One hundred two (27.9%) arteriopathies were detected in 62/167 (37.1%) patients (45 men, 17 women) with a mean age of 63.3±7.1 [SD] years (age range, 50-86 years). The incidence of arteriopathy was highly patient dependent, demonstrating significant correlation in a fully-adjusted multivariate regression model (P<0.0001). Multivariate-adjusted regression analysis with adjustment for the patient effect showed a statistically significant association of super-selective chemo-lipiodolization (P=0.003) with the incidence of arteriopathy. Thirty of the 102 arteriopathies (29.4%) caused a change in treatment strategy. No factors were found to be significantly associated with the treatment strategy change. CONCLUSION: The incidence of arteriopathy after chemo-lipiodolization is 27.9%. Among them, 29.4% result in a change in treatment strategy.

Percutaneous Endovascular Therapeutic Options in Treating Posttransplant Hepatic Artery Thrombosis With the Aim of Salvaging Liver Allografts: Our Experience.

OBJECTIVES: Hepatic artery thrombosis remains a major complication after orthoptic liver transplant. Treatment of hepatic artery thrombosis is complex and requires a multidisciplinary approach. Retransplant is the procedure of choice. In nonsurgical candidates, endovascular options are evolving. MATERIALS AND METHODS: Based on our experience at a busy transplant center, we discuss 4 representative cases to explain the potential role of endovascular treatment beyond just attempts at recanalization. From our experience, as well as a review of the literature, we propose a clinical practice algorithm for optimal treatment of hepatic artery thrombosis after orthoptic liver transplant. RESULTS: The primary traditional endovascular interventional options remain thrombectomy, balloon angioplasty, and use of stents with the aim of revascularization. However, these methods have not proven to be effective. Ultrasonography-assisted thrombolysis, which has thus far been relatively less described in the hepatic vasculature, has the potential of producing the same angiographic results but at lower doses of the thrombolytic agent, thus decreasing the potential for hemorrhagic complications. The adjunctive use of splenic artery embolization and prompt treatment of biliary complications are in our opinion useful in "buying time" to allow adequate development of collateral "neovascularization of the liver," thus preventing further ischemia. CONCLUSIONS: Although surgical retransplant still remains the standard treatment for hepatic artery thrombosis, organ shortages and high mortality still exist. Endovascular techniques are rapidly evolving, but these techniques are dependent on expertise available and, even in the best hands, have not proven to be effective at reversing hepatic artery thrombosis. The use of a multimodality endovascular approach could salvage the liver allografts, thereby preventing retransplant or facilitating transplant at a more elective setting.

Comparison of the short-term risk of bleeding and arterial thromboembolic events in nonvalvular atrial fibrillation patients newly treated with dabigatran or rivaroxaban versus vitamin K antagonists: a French nationwide propensity-matched cohort study.

BACKGROUND: The safety and effectiveness of non-vitamin K antagonist (VKA) oral anticoagulants, dabigatran or rivaroxaban, were compared with VKA in anticoagulant-naive patients with nonvalvular atrial fibrillation during the early phase of anticoagulant therapy. METHODS AND RESULTS: With the use of the French medico-administrative databases (SNIIRAM and PMSI), this nationwide cohort study included patients with nonvalvular atrial fibrillation who initiated dabigatran or rivaroxaban between July and November 2012 or VKA between July and November 2011. Patients presenting a contraindication to oral anticoagulants were excluded. Dabigatran and rivaroxaban new users were matched to VKA new users by the use of 1:2 matching on the propensity score. Patients were followed for up to 90 days until outcome, death, loss to follow-up, or December 31 of the inclusion year. Hazard ratios of hospitalizations for bleeding and arterial thromboembolic events were estimated in an intent-to-treat analysis using Cox regression models. The population was composed of 19 713 VKA, 8443 dabigatran, and 4651 rivaroxaban new users. All dabigatran- and rivaroxaban-treated patients were matched to 16 014 and 9301 VKA-treated patients, respectively. Among dabigatran-, rivaroxaban-, and their VKA-matched-treated patients, 55 and 122 and 31 and 68 bleeding events and 33 and 58 and 12 and 28 arterial thromboembolic events were observed during follow-up, respectively. After matching, no statistically significant difference in bleeding (hazard ratio, 0.88; 95% confidence interval, 0.64-1.21) or thromboembolic (hazard ratio, 1.10; 95% confidence interval, 0.72-1.69) risk was observed between dabigatran and VKA new users. Bleeding (hazard ratio, 0.98; 95% confidence interval, 0.64-1.51) and ischemic (hazard ratio, 0.93; 95% confidence interval, 0.47-1.85) risks were comparable between rivaroxaban and VKA new users. CONCLUSIONS: In this propensity-matched cohort study, our findings suggest that physicians should exercise caution when initiating either non-VKA oral anticoagulants or VKA in patients with nonvalvular atrial fibrillation.

Use of a clinical pathway to improve the acute management of vaso-occlusive crisis pain in pediatric sickle cell disease.

BACKGROUND: The most common, debilitating morbidity of sickle cell disease (SCD) is vaso-occlusive crisis (VOC) pain. Although guidelines exist for its management, they are generally not well-followed, and research in other pediatric diseases has shown that clinical pathways improve care. The purpose of our study was to determine whether a clinical pathway improves the acute management of sickle cell vaso-occlusive crisis (VOC) pain in the pediatric emergency department (PED). PROCEDURE: Pain management practices were prospectively investigated before and after the initiation of a clinical pathway in the PED of an urban, tertiary care center with 50,000 ED visits per year and approximately 200 active sickle cell patients. The pathway included instructions for triage, monitoring, medication administration, and timing of assessments and interventions. Data were eligible from 35 pre-pathway and 33 post-pathway visits. Primary outcome was time interval to administration of first analgesic medication. Statistical analysis was by Student's t-test, using natural-log-transformed data for outcomes with skewed distribution curves. RESULTS: Time interval to first analgesic improved from 74 to 42 minutes (P = 0.012) and to first opioid from 94 to 46 minutes (P = 0.013). The percentage of patients who received ketorolac increased from 57% to 82% (P = 0.03). Decrease in time interval to subsequent pain score assessment was not statistically significant (110 to 72 minutes (P = 0.07)), and change in pain score was not different (P = 0.25). CONCLUSIONS: The use of a clinical pathway for sickle cell VOC in the PED can improve important aspects of pain management and merits further investigation and implementation.

Serial analysis of clinical and imaging indices reveals prolonged efficacy of TNF-α and IL-6 receptor targeted therapies in refractory Takayasu arteritis.

OBJECTIVES: We analysed a large cohort of patients with Takayasu arteritis, seeking robust clinical evidence for prolonged responses to tumour necrosis factor-α (TNF-α) and interleukin-6 receptor (IL-6R) antagonists in severe refractory disease. METHODS: Case notes from ninety-eight patients with Takayasu arteritis were retrospectively reviewed. Drug treatment, laboratory and serial non-invasive imaging data were analysed, and the Indian Takayasu arteritis activity (ITAS) and damage scores (TADs) calculated. RESULTS: Nine patients were treated with biologic therapies. All had previously received high dose prednisolone and ≥1 conventional immunosuppressant. Five patients had failed cyclophosphamide. The patients prescribed biologics had more extensive arterial injury than the remainder of the cohort and persistent active disease (ITAS range 2-9, CRP 12-206 mg/L, TADs 3--1). Eight patients were prescribed anti-TNF-α therapy, three IL-6R blockade. The mean duration of anti-TNF-α treatment was 42 months (maximum 8 years). One patient developed new arterial stenoses while receiving anti-TNF-α and subsequently achieved disease remission with tocilizumab. Two patients have now demonstrated sustained responses to IL-6R inhibition at 19 and 20 months. Following introduction of biologic therapy, serial non-invasive imaging has revealed no significant progression in arterial injury. A significant fall in CRP (p<0.01), prednisolone dose (p<0.01) and ITAS (p<0.01) was observed, with no increase in TADs. CONCLUSIONS: We report for the first time sustained responses to both anti-TNF-α and IL6R antagonists in refractory Takayasu arteritis. As 5/9 patients were cyclophosphamide non-responders, we propose that biologics should now be considered ahead of cyclophosphamide in these young patients.

Thrombembolic occlusion of crural arteries following transcatheter aortic valve implantation--successful endovascular recanalization using a thrombus aspiration device.

Transcatheter aortic valve implantation (TAVI) has become an increasingly used alternative to conventional surgical valve replacement in patients with severe aortic valve stenosis (AS) and high operative risk. We here describe a case of a TAVI performed in local anesthesia causing intraprocedural thromboembolic occlusion of non-stenotic crural arteries and its immediate successful therapeutic management by means of endovascular recanalization using a thrombus aspiration device.

A potent oral P-selectin blocking agent improves microcirculatory blood flow and a marker of endothelial cell injury in patients with sickle cell disease.

Abnormal blood flow accounts for most of the clinical morbidity of sickle cell disease (SCD) [1,2]. Most notably, occlusion of flow in the microvasculature causes the acute pain crises [3] that are the commonest cause for patients with SCD to seek medical attention [4] and major determinants of their quality of life [5]. Based on evidence that endothelial P-selectin is central to the abnormal blood flow in SCD we provide results from four of our studies that are germane to microvascular blood flow in SCD. A proof-of-principle study established that doses of heparin lower than what are used for anticoagulation but sufficient to block P-selectin improved microvascular blood flow inpatients with SCD. An in vitro study showed that Pentosan Polysulfate Sodium (PPS) had greater P-selectin blocking activity than heparin. A Phase I clinical study demonstrated that a single oral dose of PPS increased microvascular blood flow in patients with SCD. A Phase II clinical study that was not completed documented that daily oral doses of PPS administered for 8 weeks lowered plasma levels of sVCAM-1 and tended to improve microvascular blood flow in patients with SCD. These data support the concept that P-selectin on the microvascular endothelium is critical to both acute vascular occlusion and chronically impaired microvascular blood flow in SCD. They also demonstrate that oral PPS is beneficial to microvascular sickle cell blood flow and has potential as an efficacious agent for long-term prophylactic therapy of SCD.

Micronutrients and sickle cell disease, effects on growth, infection and vaso-occlusive crisis: a systematic review.

Patients with Sickle cell disease (SCD) exhibit signs of poor growth, increased susceptibility to infection and recurrent episodes of painful vaso-occlusive crises. Micronutrient deficiencies may increase susceptibility to these outcomes. We conducted a systematic review to assess the strength of evidence for improved outcomes related to micronutrient interventions. Six randomized-controlled trials of moderate quality met the inclusion criteria. Zinc supplementation was associated with improved growth and decreased incidence of infection and is a promising intervention in the management of SCD patients. Omega-3 fatty acid supplementation was associated with limited reduction in vaso occlusive crises. This review identifies key knowledge gaps, which are important research priorities for nutritional interventions.

Cerebral infarct in a patient with a history of systemic arterial and venous thrombosis from essential thrombocythemia.

Although essential thrombocythemia (ET) may involve thrombotic complications, including arterial or venous thrombosis, there are no reports of major vascular complications, including both arterial and venous thrombosis, in a patient with ET. We report on a patient with a cerebral infarction affecting the right lateral thalamus and a stenotic lesion of the right posterior cerebral artery. This arterial thrombotic event may be related to ET, which was based on results of a bone marrow biopsy specimen. The patient had experienced previous events of thrombosis, splenic infarction with venous thrombosis, and myocardial infarction. The cause of recurrent ischemic events involving both arterial and venous systems may be sustained elevation of platelet counts. Previous thrombosis is an established risk factor for rethrombosis in patients with ET. Efficient cytoreductive therapy with an antiplatelet agent should be considered for the prevention of recurrent thrombosis.

The effect of a simulated manipulation position on internal carotid and vertebral artery blood flow in healthy individuals.

The simulated manipulation position is one of several premanipulative screening tests recommended to assist in identifying patients at risk of complications from high velocity thrust manipulation of the cervical spine. The effects of this position on blood flow in the vertebral artery has been measured, but not in the internal carotid artery. Fourteen healthy subjects participated in a pre-test post-test single group study to determine the effect of a simulated manipulation position on blood flow in both the internal carotid and vertebral arteries. Duplex ultrasound with colour Doppler imaging was used to image the internal carotid and vertebral arteries and to measure blood flow velocity with the neck in neutral and simulated manipulation positions. A measure of distal vascular resistance, the resistance index, was calculated. There was a significant (p<0.05) reduction in the resistance index in the vertebral arteries ipsilateral to the rotation component of the simulated manipulation position. Placing the cervical spine in a simulated manipulation position, did not adversely affect blood flow through the internal carotid and vertebral arteries. Further research is needed to determine how the simulated manipulation position affects internal carotid and vertebral artery blood flow in individuals who have signs or symptoms of neurovascular insufficiency.