Assessment of Vessel Density on Non-Contrast Computed Tomography to Detect Basilar Artery Occlusion.

INTRODUCTION: Basilar artery occlusion (BAO) may be clinically occult due to variable and non-specific symptomatology. We evaluated the qualitative and quantitative determination of a hyperdense basilar artery (HDBA) on non-contrast computed tomography (NCCT) brain for the diagnosis of BAO. METHODS: We conducted a case control study of patients with confirmed acute BAO vs a control group of suspected acute stroke patients without BAO. Two EM attending physicians, one third-year EM resident, and one medical student performed qualitative and quantitative assessments for the presence of a HDBA on axial NCCT images. Our primary outcome measures were sensitivity and specificity for BAO. Our secondary outcomes were inter-rater and intra-rater reliability of the qualitative and quantitative assessments. RESULTS: We included 60 BAO and 65 control patients in our analysis. Qualitative assessment of the hyperdense basilar artery sign was poorly sensitive (54%-72%) and specific (55%-89%). Quantitative measurement improved the specificity of hyperdense basilar artery assessment for diagnosing BAO, with a threshold of 61.0-63.8 Hounsfield units demonstrating relatively high specificity of 85%-94%. There was moderate inter-rater agreement for the qualitative assessment of HDBA (Fleiss' kappa statistic 0.508, 95% confidence interval: 0.435-0.581). Agreement improved for quantitative assessments, but still fell in the moderate range (Shrout-Fleiss intraclass correlation coefficient: 0.635). Intra-rater reliability for the quantitative assessments of the two attending physician reviewers demonstrated substantial consistency. CONCLUSION: Our results highlight the importance of carefully examining basilar artery density when interpreting the NCCT of patients with altered consciousness or other signs and symptoms concerning for an acute basilar artery occlusion. If the Hounsfield unit density of the basilar artery exceeds 61 Hounsfield units, BAO should be highly suspected.

The impact of female sex on the outcomes of endovascular treatment for iliac lesions.

OBJECTIVE: The aim of this study was to evaluate early and long-term outcomes of stenting for iliac obstructive disease in women, comparing their results with those of men. METHODS: A single-center retrospective analysis of iliac stenting procedures performed from 2010 to 2017 was conducted. Perioperative clinical, anatomic, and operative data, including mean artery diameters and stent diameters, were collected in a dedicated database. Early outcomes and long-term patency rates were compared between men and women; Cox proportional hazards modeling was used to identify independent predictors of patency. RESULTS: There were 210 patients (298 limbs; women, n = 80 limbs [33%]; men, n = 218 limbs [66%]) treated. In comparing women with men, there were no differences in comorbidities (Society for Vascular Surgery score: women, 0.81 ± 0.54; men, 0.84 ± 0.60; P = .69) and TransAtlantic Inter-Society Consensus (TASC) classification (P = .49). At presentation, women had more advanced symptoms (Rutherford categories 5 and 6: women, 36.2%; men, 23.8%; P = .039) and smaller diameter at the level of the aortic bifurcation (women, 14.5 ± 3.6 mm; men, 16.0 ± 3.3 mm; P = .017), common iliac artery (women, 9.3 ± 1.5 mm; men, 10.0 ± 1.6 mm; P < .001), external iliac artery (EIA; women, 8.7 ± 1.5 mm; men, 10.1 ± 2.6 mm; P = .006), and common femoral artery (women, 7.3 ± 2.0 mm; men, 8.5 ± 2.1 mm; P = .034); similarly, the mean stent diameter was smaller (women, 8.9 ± 1.7 mm; men, 10.1 ± 4.4 mm; P = .03). The 30-day medical (P = .22) and surgical (P = .50) complication rates were similar. At 72 months, women had lower primary patency (women, 71%; men, 88%; P = .020) and secondary patency (women, 83%; men, 97%; P < .001) rates compared with men, whereas limb salvage rate was similar (women, 96%; men, 99%; P = .501). Multivariable analysis showed that female sex (hazard ratio [HR], 2.49; P = .04), ischemic tissue loss (HR, 2.48; P = .04), and stent diameter ≤7 mm (HR, 2.86; P = .01) were overall negative predictors of patency. Within women, EIA involvement (HR, 2.01; P = .04) and stent diameter ≤7 mm (HR, 3.79; P = .12) were also negative predictors. CONCLUSIONS: Iliac stenting shows similarly good early outcomes in women and men. However, in the long term, primary and secondary patency rates are significantly lower in women, and this may be explained by smaller arterial diameter. In particular, a stent diameter ≤7 mm and EIA stenting were negative predictors of patency.

Endovascular Approach Versus Aortobifemoral Bypass Grafting: Outcomes in Extensive Aortoiliac Occlusive Disease.

OBJECTIVE: Compare technical, clinical, and economic outcomes between endovascular and open approaches in patients with type D aortoiliac occlusive disease according to the TransAtlantic Inter-Society Consensus. METHODS: Patients undergoing revascularization for type D aortoiliac lesions, either endovascular or open surgery approach, from 2 Portuguese institutions between January 2011 and October 2017 were included. The surgical technique was left to the surgeon discretion. Patients with common femoral artery affection, both obstructive and aneurysmatic, were excluded. RESULTS: Twenty-seven patients underwent aortobifemoral bypass and 32 patients were submitted to endovascular repair. The patients undergoing endovascular procedure were more likely to present with chronic heart failure (P = .001) and chronic kidney disease (P = .022) and less likely to have a history of smoking (P = .05). The mean follow-up period was 67.84 (95% confidence interval = 61.85-73.83) months. The open surgery approach resulted in a higher technical success (P = .001); however, limb salvage and patency rates were not different between groups. Endovascular approach was associated with a shorter length-of-stay, both inpatient (6 vs 9 days; P = .041) and patients admitted in the intensive care unit (0 vs 3.81 days; P = .001) as well as lower hospital expenses (US$9281 vs US$23 038; P = .001) with a similar procedure cost (US$2316 vs US$1173; P = .6). No differences were found in the postsurgical quality of life. CONCLUSION: Endovascular approach is, at least, clinically equivalent to open surgery approach and is more cost-efficient. The "endovascular-first" approach should be considered for type D occlusive aortoiliac lesions.

[Follow-up of patients with chronic obstructive arterial disease, some months after their rehabilitation: Assessment of a therapeutic education program]. / Suivi de patients atteints d'artériopathie oblitérante des membres inférieurs, à distance d'une rééducation : évaluation d'un programme d'éducation thérapeutique.

Vascular rehabilitation (VR) is becoming increasingly important in the management of the arterial patient. Therapeutic Patient Education (TPE) is an integral part of rehabilitation programs and aims to transform patients' lifestyle habits. The effectiveness of patient management at short-term no longer needs to be demonstrated, but we can question the effectiveness of education over the long term, some months following a rehabilitation program. OBJECTIVE: This study aims to assess, in the long term, the effects of TPE in VR, and to observe the transformation of certain lifestyle habits of patients. METHOD: We convened 68 patients (51 men and 17 women) 6 months and 1 year after VR treatment during which these patients participated in an TPE program. We assessed: knowledge by questionnaire, walking range, weight and body composition by impedimetric techniques. RESULTS: We found that patients improved their knowledge at the end of rehabilitation 45.8 (±7.6) of good responses on average, compared to 36.2 (±8.6) at the beginning of rehabilitation and these results are consolidated 6 months after 43.4 (±7.5) and 1 year after 44.1 (±8.1). We also found that walking distances during treadmill testing and outdoor walking improved at the end of rehabilitation and were maintained at six months and one year. Finally, weight, fat mass and lean mass decreased slightly compared to the end of rehabilitation. Only 7 patients out of 22 gave up smoking. CONCLUSION: An education program concerning risk factor management during vascular rehabilitation enables patients to acquire knowledge that can be used to maintain new lifestyle habits and stabilize their health status.

[Objective assessment of the degree of ischaemia and efficacy of treatment in chronic arterial insufficiency of lower limbs]. / Ob''ektivnaia otsenka stepeni ishemii i éffektivnosti lecheniia pri khronicheskoi arterial'noi nedostatochnosti nizhnikh konechnostei.

Presented in the review is the data concerning contemporary criteria for assessing the degree of chronic lower limb ischaemia and quality of the treatment performed. Problems regarding objectivization of the degree of an ischaemic lesion of an extremity and assessment of quality of conservative treatment still remain unresolved. Currently, in the world practice along with instrumental methods (assessment of the ankle-brachial index) subjective criteria are mainly employed: assessment of pain-free walking distance or maximum distance walked. In order to work out appropriate regiments of conservative treatment and compare efficacy of various drugs for treatment of chronic lower limb ischaemia and, in particular, intermittent claudication, it is necessary to use objective criteria. Detailed consideration is hence given to the possibilities of using morphological, biochemical and histological criteria such as determination of vascular endothelial growth factor A (VEGF-A) in peripheral blood and determination of apoptosis markers (BNIP3) and hypoxia-inducible factor (HIF-1) in a biopsy sample of the gastrocnemius muscle of the ischaemized extremity.

Celiac axis stenosis due to median arcuate ligament compression in a patient who underwent pancreatoduodenectomy; intraoperative assessment of hepatic arterial flow using Doppler ultrasonography: a case report.

BACKGROUND: Celiac axis stenosis due to compression by the median arcuate ligament has been reported in patients undergoing pancreaticoduodenectomy; it leads to the development of major collateral pathways that feed the hepatic artery. Dividing these important collaterals during pancreaticoduodenectomy can cause ischemic complications which may lead to a high mortality rate. To prevent these complications, it is necessary to assess intrahepatic arterial flow. CASE PRESENTATION: A 71-year-old Japanese man with anorexia was referred to us for the treatment of alcoholic chronic pancreatitis. Computed tomography revealed a pancreatic head tumor with a calculus, associated with the dilatation of the main pancreatic duct and intrahepatic bile duct. Three-dimensional imaging demonstrated focal narrowing in the proximal celiac axis due to median arcuate ligament compression and a prominent gastroduodenal artery that fed the common hepatic artery. The preoperative diagnosis was alcoholic chronic pancreatitis with common bile duct obstruction and celiac axis stenosis due to median arcuate ligament compression. Pancreaticoduodenectomy with median arcuate ligament release was scheduled. Before the division of the median arcuate ligament, the peak flow velocity and resistive index of his intrahepatic artery measured with Doppler ultrasonography decreased from 37.7 cm/second and 0.510, respectively, to 20.6 cm/second and 0.508 respectively, when his gastroduodenal artery was clamped. However, these values returned to baseline levels after the division of the median arcuate ligament. These findings suggested that pancreaticoduodenectomy could be performed safely. Our patient was discharged on postoperative day 17 without significant complications. CONCLUSION: The intraoperative quantitative evaluation of intrahepatic arterial blood flow using Doppler ultrasonography was useful in a patient who underwent pancreaticoduodenectomy, who had celiac axis stenosis due to compression by the median arcuate ligament.

Hemodynamic significance assessment of equivocal iliac artery stenoses by comparing duplex ultrasonography with intra-arterial pressure measurements.

BACKGROUND: This study evaluated the accuracy of duplex ultrasonography (DUS)-based peak systolic velocity ratio (PSVR) and ipsilateral common femoral artery (CFA) velocity waveform analysis to identify a hemodynamically significant equivocal iliac artery stenosis (30-75% lumen diameter reduction). Intra-arterial pressure measurements were used as a reference. METHODS: In a previously performed prospective study (NTR5085), 30 patients with 35 iliac artery stenoses underwent intra-arterial angiography. To determine the hemodynamic significance of the iliac artery stenoses, intra-arterial translesional pressure measurements were performed under hyperemic conditions. Preprocedural DUS was obtained of the iliac and femoral arteries. PSVR over the iliac lesions was determined, and ipsilateral CFA velocity waveforms were retrospectively classified. The intraobserver and interobserver agreement for CFA velocity waveform classification were evaluated. Sensitivity, specificity, and overall accuracy were calculated by comparing PSVR, velocity waveform analysis, and a combination of these parameters to the intra-arterial translesional pressure gradient. A translesional pressure gradient ≥10 mmHg, PSVR ≥2.5, and a monophasic or biphasic CFA velocity waveform were considered to be indicative for a hemodynamically significant iliac artery stenosis. RESULTS: For classification of ipsilateral CFA velocity waveforms, intraobserver and interobserver agreement were 0.94 and 0.82, respectively. A PSVR ≥2.5 could identify a hemodynamically significant stenosis with 83% sensitivity, 67% specificity, and an overall accuracy of 77%. When both a monophasic and a biphasic velocity waveform were considered to indicate a hemodynamically significant iliac artery stenosis, sensitivity was 78%, specificity was 50%, and the overall accuracy was 69%. The combination of a PSVR ≥2.5 with either a monophasic or a biphasic CFA velocity waveform was found in 20 stenoses and resulted in 94% sensitivity, 75% specificity, and 90% accuracy. When the remainder of the stenoses (N.=15) was classified by means of the PSVR, the overall accuracy remained 77%. CONCLUSIONS: DUS is a very useful noninvasive imaging modality to determine the significance of an iliac artery stenosis. A combination of translesional PSVR ≥2.5 with either a monophasic or a biphasic ipsilateral CFA ultrasound waveforms has a good accuracy and helps to select patients that benefit most from follow-up examination by computed tomography angiography or magnetic resonance angiography.

In Vivo Validation of Patient-Specific Pressure Gradient Calculations for Iliac Artery Stenosis Severity Assessment.

BACKGROUND: Currently, the decision to treat iliac artery stenoses is mainly based on visual inspection of digital subtraction angiographies. Intra-arterial pressure measurements can provide clinicians with accurate hemodynamic information. However, pressure measurements are rarely performed because of their invasiveness and the time required. Therefore, the aim of the study was to test the feasibility of a computational model that can predict translesional pressure gradients across iliac artery stenoses on the basis of imaging data only. METHODS AND RESULTS: Patients (N=21) with symptomatic peripheral arterial disease and a peak systolic velocity ratio between 2.5 and 5.0 were included in the study. Patients underwent per-procedural 3-dimensional rotational angiography and hyperemic intra-arterial translesional pressure measurements. Vascular anatomical features were reconstructed from the 3-dimensional rotational angiography data into an axisymmetrical 2-dimensional computational mesh, and flow was estimated on the basis of the stenosis geometry. Computational fluid dynamics were performed to predict the pressure gradient and were compared with the measured pressure gradients. A good agreement by overlapping error bars of the predicted and measured pressure gradients was found in 21 of 25 lesions. Stratification of the stenosis on the basis of the predicted pressure gradient into hemodynamic not significant (<10 mm Hg) and hemodynamic significant (≥10 mm Hg) resulted in sensitivity, specificity, and overall predictive values of 95%, 60%, and 88%, respectively. CONCLUSIONS: The feasibility of the patient-specific computational model to predict the hyperemic translesional pressure gradient over iliac artery stenosis was successfully tested. Presented results suggest that, with further optimization and corroboration, the model can become a valuable aid to the diagnosis of equivocal iliac artery stenosis. CLINICAL TRIAL REGISTRATION: URL: http://www.trialregister.nl. Unique identifier: NTR5085.

Zenith Bifurcated Iliac Side Branch Device: Mid-term Results and Assessment of Risk Factors for Intraoperative Thrombosis.

BACKGROUND: The aim of this study is to evaluate the short- and mid-term results of the Zenith bifurcated iliac side branch device (ZBIS) in the treatment of common iliac artery (CIA) aneurysms, and to assess risk factors for intraoperative internal iliac artery (IIA) thrombosis. METHODS: All patients who underwent endovascular treatment of either an isolated CIA aneurysm or an aortoiliac aneurysm using the ZBIS device in the departments of vascular surgery of Strasbourg (France) and Lausanne (Switzerland) between January 2010 and December 2014 were retrospectively collected. RESULTS: Thirty-one implantations were performed: 30 patients underwent 31 endovascular CIA aneurysm treatments with the ZBIS device. Mean operative time was 188 min. Technical success was obtained in 26 implantations (84%). In 5 implantations (16%), the final angiogram revealed an IIA thrombosis. Thirty-day mortality was 3.2%. Thirty-day morbidity was 13.3%. Mean follow-up was 15 months. Overall survival was 96% at 1 year and 89% at 2 years. In intention-to-treat analysis, primary patency of the internal iliac side branch was 84% at 1 year and 76% at 2 years (5 peroperative IIA occlusions and 1 late occlusion). Freedom from reintervention was 89% at 1 and 2 years. One case of type III endoleak and 2 cases of type II endoleaks were identified. Only type III endoleak required an additional intervention with a covered stent. Aneurysm diameter decreased in 15 implantations (48%) and remained stable in 16 implantations (52%). Clinical, radiological, and peroperative parameters were analyzed to identify risk factor for intraoperative thrombosis of the internal iliac side branch. Notion of intraoperative difficulties (any additional procedure that was not initially planned and increasing the operating time) appeared as a risk factor in multivariate analysis (P < 0.01, standard deviation 1.27, odds ratio 30.6). CONCLUSIONS: The main findings of our study is that the procedure can be difficult to perform in particular conditions and can lead to peroperative failure in these cases, highlighting the need for adequate patients screening. When technical success is obtained, outcomes can be considered as satisfactory.

Severity assessment of intracranial large artery stenosis by pressure gradient measurements: A feasibility study.

BACKGROUND: Fractional flow reserve (FFR)-guided revascularization strategy is popular in coronary intervention. However, the feasibility of assessing stenotic severity in intracranial large arteries using pressure gradient measurements still remains unclear. METHODS: Between March 2013 and May 2014, 12 consecutive patients with intracranial large artery stenosis (including intracranial internal carotid artery, middle cerebral M1 segment, intracranial vertebral artery, and basilar artery) were enrolled in this study. The trans-stenotic pressure gradient was measured before and/or after percutaneous transluminal angioplasty and stenting (PTAS), and was then compared with percent diameter stenosis. A Pd /Pa cut-off of ≤0.70 was used to guide stenting of hemodynamically significant stenoses. The device-related and procedure-related serious adverse events and recurrent cerebral ischemic events were recorded. RESULTS: The target vessel could be reached in all cases. No technical complications occurred due to the specific study protocol. Excellent pressure signals were obtained in all patients. For seven patients who performed PTAS, the mean pre-procedural pressure gradient decreased from 59.0 ± 17.2 to 13.3 ± 13.6 mm Hg after the procedure (P < 0.01). Only one patient who refused stenting experienced a TIA event in the ipsilateral MCA territory. No recurrent ischemic event was observed in other patients. CONCLUSION: Mean trans-stenotic pressure gradients can be safely and easily measured with a 0.014-inch fluid-filled guide wire in intracranial large arteries. © 2016 Wiley Periodicals, Inc.

Technical assessment of whole body angiography and cardiac function within a single MRI examination.

AIM: To evaluate a combined protocol for simultaneous cardiac MRI (CMR) and contrast-enhanced (CE) whole-body MR angiography (WB-MRA) techniques within a single examination. MATERIALS AND METHODS: Asymptomatic volunteers (n = 48) with low-moderate risk of cardiovascular disease (CVD) were recruited. The protocol was divided into four sections: (1) CMR of left ventricle (LV) structure and function; (2) CE-MRA of the head, neck, and thorax followed by the distal lower limbs; (3) CMR LV "late gadolinium enhancement" assessment; and (4) CE-MRA of the abdomen and pelvis followed by the proximal lower limbs. Multiple observers undertook the image analysis. RESULTS: For CMR, the mean ejection fraction (EF) was 67.3 ± 4.8% and mean left ventricular mass (LVM) was 100.3 ± 22.8 g. The intra-observer repeatability for EF ranged from 2.1-4.7% and from 9-12 g for LVM. Interobserver repeatability was 8.1% for EF and 19.1 g for LVM. No LV delayed myocardial enhancement was observed. For WB-MRA, some degree of luminal narrowing or stenosis was seen at 3.6% of the vessel segments (involving n = 29 of 48 volunteers) and interobserver radiological opinion was consistent in 96.7% of 1488 vessel segments assessed. CONCLUSION: Combined assessment of WB-MRA and CMR can be undertaken within a single examination on a clinical MRI system. The associated analysis techniques are repeatable and may be suitable for larger-scale cardiovascular MRI studies.

Assessment of peripheral skeletal muscle microperfusion in a porcine model of peripheral arterial stenosis by steady-state contrast-enhanced ultrasound and Doppler flow measurement.

OBJECTIVE: Noninvasive measurement of peripheral muscle microperfusion could potentially improve diagnosis, management, and treatment of peripheral arterial disease (PAD) and thus improve patient care. Contrast-enhanced ultrasound (CEUS) as a noninvasive diagnostic tool allows quantification of muscle perfusion. Increasing data on bolus technique CEUS reflecting microperfusion are becoming available, but only limited data on steady-state CEUS for assessment of muscle microperfusion are available. Therefore, the aim of this study was to evaluate steady-state CEUS for assessment of peripheral muscle microperfusion in a PAD animal model. METHODS: In a porcine animal model, peripheral muscle microperfusion was quantified by steady-state CEUS replenishment kinetics (mean transit time [mTT] and wash-in rate [WiR]) of the biceps femoris muscle during intravenous steady-state infusion of INN-sulfur hexafluoride (SonoVue; Bracco, Geneva, Switzerland). In addition, macroperfusion was quantified at the external femoral artery with a Doppler flow probe. Peripheral muscle microperfusion and Doppler flow measurements were performed bilaterally at rest and under adenosine stress (70 µg/kg body weight) before and after unilateral creation of a moderate external iliac artery stenosis. RESULTS: All measurements could be performed completely in 10 pigs. Compared with baseline measurements, peripheral muscle microperfusion decreased significantly during adenosine stress (rest vs adenosine stress: mTT, 7.8 ± 3.3 vs 21.2 ± 17.8 s, P = .0006; WiR, 58.4 ± 38.1 vs 25.3 ± 15.6 arbitrary units [a.u.]/s, P < .0001; Doppler flow, 122.3 ± 31.4 vs 83.6 ± 28.1 mL/min, P = .0067) and after stenosis creation (no stenosis vs stenosis: mTT, 8.1 ± 3.1 vs 29.2 ± 18.0 s, P = .0469; WiR, 53.0 ± 22.7 vs 13.6 ± 8.4 a.u./s, P = .0156; Doppler flow, 124.2 ± 41.8 vs 65.9 ± 40.0 mL/min, P = .0313). After stenosis creation, adenosine stress led to a further significant decrease of peripheral muscle microperfusion but had no effect on macroperfusion (mTT, 29.2 ± 18.0 vs 56.3 ± 38.7 s, P = .0078; WiR, 13.6 ± 8.4 vs 6.0 ± 4.1 a.u./s, P = .0078; Doppler flow, 65.9 ± 40.0 vs 79.2 ± 29.6 mL/min, P = .8125). Receiver operating characteristic curves for the presence of inflow stenosis showed an excellent area under the curve of 0.93 for mTT at rest and 0.86 for Doppler flow. CONCLUSIONS: Peripheral muscle microperfusion measurement by steady-state CEUS with replenishment kinetics is feasible and allows detection of muscle microperfusion changes caused by vasodilative stress alone or in combination with a moderate inflow stenosis. Steady-state CEUS offers superior diagnostic performance compared with Doppler flow measurements. Therefore, steady-state CEUS may prove to be a useful tool in diagnosis of PAD and for evaluation of new therapies.

A nonlinear finite element simulation of balloon expandable stent for assessment of plaque vulnerability inside a stenotic artery.

The stresses induced on plaque wall during stent implantation inside a stenotic artery are associated with plaque rupture. The stresses in the plaque-artery-stent structure appear to be distinctly different for different plaque types in terms of both distribution and magnitude. In this study, a nonlinear finite element simulation was executed to analyze the influence of plaque composition (calcified, cellular, and hypocellular) on plaque, artery layers (intima, media, and adventitia), and stent stresses during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal arterial tissues on its outer side. The results revealed a significant influence of plaque types on the maximum stresses induced within plaque wall and artery layers during stenting, but not when calculating maximum stress on stent. The stress on stiffer calcified plaque wall was in the fracture level (2.21 MPa), whereas cellular and hypocellular plaques play a protective role by displaying less stress on their wall. The highest von Mises stresses were observed on less stiff media layer. The findings of this study suggest a lower risk of arterial vascular injury for calcified plaque, while higher risk of plaque ruptures for cellular and hypocellular plaques.

Assessment of right ventricular structure and function in mouse model of pulmonary artery constriction by transthoracic echocardiography.

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure(1-3). Moreover, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction(4). To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential. A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software. Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC. Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.

Direct quantitative assessment of the peripheral artery collateral circulation in patients undergoing angiography.

BACKGROUND: Despite the fact that numerous studies have pursued the strategy of improving collateral function in patients with peripheral artery disease, there is currently no method available to quantify collateral arterial function of the lower limb. METHODS AND RESULTS: Pressure-derived collateral flow index (CFIp, calculated as (occlusive pressure-central venous pressure)/(aortic pressure-central venous pressure); pressure values in mm Hg) of the left superficial femoral artery was obtained in patients undergoing elective coronary angiography using a combined pressure/Doppler wire (n=30). Distal occlusive pressure and toe oxygen saturation (Sao2) were measured for 5 minutes under resting conditions, followed by an exercise protocol (repetitive plantar-flexion movements in supine position; n=28). In all patients, balloon occlusion of the superficial femoral artery over 5 minutes was painless under resting conditions. CFIp increased during the first 3 minutes from 0.451±0.168 to 0.551±0.172 (P=0.0003), whereas Sao2 decreased from 98±2% to 93±7% (P=0.004). Maximal changes of Sao2 were inversely related to maximal CFIp (r(2)=0.33, P=0.003). During exercise, CFIp declined within 1 minute from 0.560±0.178 to 0.393±0.168 (P<0.0001) and reached its minimum after 2 minutes of exercise (0.347±0.176), whereas Sao2 declined to a minimum of 86±6% (P=0.002). Twenty-five patients (89%) experienced pain or cramps/tired muscles, whereas 3 (11%) remained symptom-free for an occlusion time of 10 minutes. CFIp values were positively related to the pain-free time span (r(2)=0.50, P=0.002). CONCLUSIONS: Quantitatively assessed collateral arterial function at rest determined in the nonstenotic superficial femoral artery is sufficient to prevent ischemic symptoms during a total occlusion of 5 minutes. During exercise, there is a decline in CFIp that indicates a supply-demand mismatch via collaterals or, alternatively, a steal phenomenon. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. UNIQUE IDENTIFIER: NCT01742455.

Quantitative assessment of cerebral hemodynamics using single photon emission computed tomography with venous blood sampling.

OBJECTIVE: Quantitative cerebral blood flow (CBF) measured by single photon emission computed tomography (SPECT) with arterial blood sampling is one of the most reliable methods to assess the hemodynamics in individual patients. SPECT with venous blood sampling is less invasive. The present study compared the measurement of CBF using N-isopropyl-p-(iodine-123)-iodoamphetamine SPECT with venous blood sampling and with arterial blood sampling in patients with major cerebral artery occlusive disease. METHODS: Two normal subjects and 14 patients with major cerebral artery occlusive disease underwent SPECT with arterial and venous blood sampling. The microsphere method was used for quantitative SPECT imaging. Whole brain radioactivity was corrected when the detectors rotated in the forward direction (F1-F7). Venous sampling was performed 30min after radiotracer injection. Arterial blood radioactivity was estimated by multiple regression analysis from these parameters. The cerebrovascular reactivity to acetazolamide was also measured. RESULTS: Multiple regression analysis established the following formula:(where Ca10 is the arterial blood radioactivity at 10min, F1-F7 are the whole brain radioactivity in the forward direction, Cv30 is the venous blood radioactivity at 30min). Mean CBF values were 32.2±6.6ml/100g/min for measured arterial radioactivity and 42.2±7.8ml/100g/min for calculated arterial radioactivity based on venous radioactivity. CONCLUSIONS: The present modified method of calculating quantitative CBF from whole brain and venous blood radioactivities correlated well with values determined with arterial blood radioactivity.

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.

Utility of new classification based on clinical and lesional factors after self-expandable nitinol stenting in the superficial femoral artery.

BACKGROUND: The aim of this study was to investigate the predictive value of clinical classification schemes that assess primary patency after self-expandable nitinol stent in the superficial femoral artery (SFA). METHODS: This study was a multicenter retrospective study of prospective databases. From April 2004 to December 2009, 1001 limbs (807 patients) that underwent successful nitinol stent implantation for de novo SFA lesions were identified and analyzed. Primary patency was defined as treated vessel without restenosis (defined as >2.4 of peak systolic velocity ratio by duplex) and repeat revascularization. Six items were included in the classification: female, diabetes, dialysis, critical limb ischemia (CLI), lesion length > 150 mm, and poor runoff; the FeDCLIP score. A lesion length >150 mm was scored as 2 points. The others were assigned 1 point each. The scores of 0 to 2, 3 to 4, and ≥5 points were classified as low-, moderate-, and high-risk patients, respectively. Outcome measures were primary and secondary patency and all-cause mortality up to 6 years in each risk group. RESULTS: The mean follow-up interval was 26.8 ± 14.6 months. Primary patencies were 85.7%, 77.3%, and 74.2% in the low-risk group; 71.5%, 54.7%, and 51.9% in the moderate-risk group; and 53.0%, 24.3%, and 20.8% in the high-risk group at 1, 3, and 5 years, respectively. The secondary patencies were 94.6%, 92.3%, and 90.8% in the low-risk group; 89.5%, 83.1%, and 83.1% in the moderate-risk group; and 82.7%, 73.1%, and 73.1% in the high-risk group at 1, 3, and 5 years, respectively. There were significant differences in primary and secondary patency among the three risk groups (P < .0001 and P < .0001, respectively). Overall survival rates were 96.8%, 89.5%, and 81.8% in the low-risk group; 91.5%, 74.4%, and 68.7% in the moderate-risk group; and 78.2%, 63.2%, and 48.7% in the high-risk group at 1, 3, and 5 years, respectively. There were also significant differences in mortality (P < .0001). CONCLUSIONS: New classification schemes based on FeDCLIP score were useful for risk stratification in vessel patency and mortality after self-expandable nitinol stenting for SFA disease.