Peak Systolic Velocity Ratio Research Articles

Histopathological Evidence of Adventitial or Medial Injury Is a Strong Predictor of Restenosis During Directional Atherectomy for Peripheral Artery Disease

Purpose: To investigate the impact on restenosis rates of deep injury to the adventitial layer during directional atherectomy. Methods: Between 2007 and 2010, 116 consecutive patients (mean age 69.6 years; 56 men) with symptomatic femoropopliteal stenoses were treated with directional atherectomy at a single center. All patients had claudication and TASC A/B lesions in the superficial femoral or popliteal arteries. Histopathology analysis of atherectomy specimens was performed to identify adventitial injury. Clinical follow-up included physical examination and duplex ultrasound scans at 3, 6, and 12 months in all patients. The primary endpoint was the duplex-documented 1-year rate of restenosis, which was determined by a peak systolic velocity ratio <2.4. Patients were dichotomized by the presence or absence of adventitial or medial cuts as evaluated by histopathology. Results: Adventitial injury were identified in 62 (53%) of patients. There were no differences in baseline demographic and clinical features (p>0.05), lesion length (58.7±12.8 vs 56.2±13.6 mm, p=0.40), or vessel runoff (1.9±0.6 vs 2.0±0.6, p=0.37) between patients with and without adventitial injury, respectively. The overall 1-year incidence of restenosis was 57%, but the rate was significantly higher (p<0.0001) in patients with adventitial or medial injury (97%, 60/62) as compared with those without (11%, 6/54). Conclusion: Lack of adventitial injury after atherectomy for femoropopliteal stenosis is strongly related to patency at 1 year.

Common carotid artery peak systolic velocity ratio predicts high-grade common carotid stenosis

Screening for common carotid artery (CCA) stenosis with duplex ultrasound (DUS) velocity criteria alone can be limited by within-patient and between-patients hemodynamic variability. This study aimed to evaluate inter-CCA velocity ratio criteria to predict high-grade CCA stenosis. This was a retrospective review of consecutive patients who underwent computed tomography angiography and DUS peak systolic velocity (PSV) measurements of bilateral CCAs, independently recorded, between 2008 and 2014. Patients with dampened CCA waveforms on DUS composed group B. The remainder without dampened waveforms constituted group A. Inter-CCA PSV ratios were calculated by dividing the higher CCA PSV by the lower one of the other side, so the ratios would always be ≥1. Ratios were subsequently paired with each respective unilateral CCA diameter stenosis and differential bilateral CCA diameter stenosis. A quadratic regression model was fitted to predict unilateral and differential stenosis. Receiver operating characteristic curve was used to determine optimal ratios for ≥50% and ≥80% CCA stenosis. The study excluded patients with carotid artery occlusion. From a total of 201 patients, 193 patients were included in group A and 8 in group B. Within group A, 31 patients had ≥50% unilateral stenosis and 17 had ≥50% differential stenosis. All stenoses ≥50% were identified on the same side with the higher PSV. Inter-CCA PSV ratio predicted ≥50% unilateral (r(2) = 0.536; P < .001) and differential stenosis (r(2) = 0.581; P < .001). In group B, all patients had ≥60% stenosis that was near or involved the vessel origin. An increasing inter-CCA PSV ratio showed a trend toward contralateral high-grade stenosis (r(2) = 0.596; P = .1). Receiver operating characteristic curves showed an optimal threshold CCA ratio ≥2.16 for ≥50% unilateral stenosis with 92% accuracy, 62% sensitivity, and 98% specificity (area under curve = 0.854; 95% confidence interval, 0.759-0.948) and a ratio ≥2.62 for ≥50% differential stenosis with 97% accuracy, 83% sensitivity, and 98% specificity (area under curve = 0.94; 95% confidence interval, 0.835-1). DUS-based CCA PSV ratio can accurately predict unilateral and differential high-grade CCA stenosis. Also, in patients with unilateral dampened waveforms, it implied contralateral severe proximal stenosis. This parameter should be further validated in prospective studies and may serve as an adjunct screening tool to detect high-grade CCA stenosis.

Laser Atherectomy for Treatment of Femoropopliteal In-Stent Restenosis

Purpose: To investigate if laser atherectomy with adjunctive balloon angioplasty can improve endovascular treatment outcomes for femoropopliteal in-stent restenosis (ISR). Methods: A dual center study included 135 symptomatic patients (mean age 71 years; 76 men) who underwent endovascular treatment of femoropopliteal ISR between 2006 and 2013. Of these, 54 (40%) were treated with laser atherectomy and the remaining 81 patients with balloon angioplasty alone. Angiographic images were reviewed for lesion morphology and characteristics, TransAtlantic InterSociety Consensus (TASC) II classification, and distal runoff. Class I ISR was defined as focal lesions ≤50 mm, class II ISR as lesions >50 mm, and class III ISR as stent total occlusion. Recurrent ISR was determined by a peak systolic velocity ratio >2.4 by duplex ultrasound. Results: Patients treated with laser atherectomy had longer mean ISR lesion length (222 vs 114 mm, p<0.001) and more class III ISR (69% vs 20%, p=0.001). There was no association between laser atherectomy and rates of recurrent restenosis or occlusion for patients with class I/II ISR, but there was a significantly lower rate of target lesion revascularization at 2 years among patients treated with laser atherectomy (14% vs 44%, p=0.05). In comparison, patients with class III ISR treated with laser atherectomy had lower rates of recurrent restenosis at 1 year (54% vs 91%, p=0.05) and 2 years (69% vs 100%, p=0.05). Patients with class III ISR treated with laser atherectomy also had lower rates of recurrent in-stent occlusion at 2-year follow-up (33% vs 71%, p=0.04). Conclusion: When used to treat complex ISR, including in-stent occlusions, laser atherectomy with adjunctive balloon angioplasty may be associated with improved patency.

Assessment of maternal Doppler parameters of ophthalmic artery in fetuses with growth restriction in the third trimester of pregnancy: A case-control study.

The aim of this study was to assess the Doppler parameters of the ophthalmic artery of pregnant women carrying fetuses with growth restriction (FGR) compared with normal fetuses. A prospective cross-sectional study was conducted with 120 pregnant women (60 FGR and 60 normal fetuses) between 32 and 40 weeks of gestation. FGR diagnosis was based on an estimated fetal weight below the 10th percentile of the Hadlock curve. Ophthalmic artery Doppler images were obtained with a linear transducer, with color Doppler examination of the region medial to the optic nerve. The following indices were obtained: pulsatility index, resistance index, peak systolic velocity, second peak velocity (P2), end diastolic velocity, and P2 / peak systolic velocity ratio. The Mann-Whitney U-test and Student's t-test were used to compare the groups with regard to quantitative variables, and the χ(2) -test was used for categorical variables. Pulsatility index and resistance index were significantly lower in pregnant women with FGR than in those with normal fetuses, with P < 0.001 in both indices. P2 and end diastolic velocity were significantly higher in pregnant women with FGR than in those with normal fetuses (P = 0.002 and P = 0.004, respectively). The P2 / peak systolic velocity ratio was significantly higher in the FGR group than in the control group (P < 0.001). In FGR subgroups, with (17 fetuses) and without (43 fetuses) uterine artery Doppler abnormalities, no significant changes were observed between the groups. In the third trimester of pregnancy, we observed significant differences in the ophthalmic artery Doppler parameters of pregnant women with FGR compared with those with normal fetuses.

Intravascular Ultrasound Measurements After Drug-Eluting Stent Placement in Femoropopliteal Lesions

Purpose: To investigate the relationship between postprocedure intravascular ultrasound (IVUS) findings and restenosis after placement of drug-eluting stents (DES) for femoropopliteal lesions. Methods: Between July 2012 and May 2013, DES were placed in 64 patients with 88 de novo femoropopliteal lesions. In 40 patients (mean age 74.2±9.4 years; 27 men), DES were placed in 50 lesions under IVUS guidance, and restenosis was monitored for 1 year. All patients were symptomatic (Rutherford 2–6), and 17 patients (43%) suffered from critical limb ischemia. IVUS findings after stenting were compared for patients with vs without restenosis, which was defined as a peak systolic velocity ratio >2.4 on duplex ultrasonography or >50% diameter stenosis on angiography. Results: Ten patients (14 lesions) developed restenosis, while 30 patients (36 lesions) did not. There were no significant differences in the frequency of diabetes or dialysis between the 2 groups. Female patients were predominant in the restenosis group (p<0.003). There were no significant differences of the percentage of TransAtlantic Inter-Society Consensus C/D lesions or stent edge dissection. Multivariate analysis indicated that cilostazol use [odds ratio (OR) 0.13; p=0.046], distal lumen cross-sectional area (CSA) (OR 0.86; p=0.035), and axial symmetry index (OR 0.60; p=0.045) were independent predictors of restenosis. Using receiver operator characteristic analysis, the best cutoff values of the distal lumen CSA and axial symmetry index for predicting restenosis were 17.1 cm2 and 0.6, respectively. Conclusion: IVUS guidance of DES placement in femoropopliteal lesions can offer useful predictors of restenosis at 1 year. The utility of distal lumen CSA and the axial symmetry index in the prediction of restenosis after femoropopliteal DES placement should be confirmed in a larger cohort.

Stent Fractures After Superficial Femoral Artery Stenting

Purpose: To determine the risk factors and clinical impact of stent fractures after superficial femoral artery (SFA) stenting. Methods: From May 2009 to June 2012, 171 consecutive patients (mean age 74.5±7.8, years; 106 men) who presented with SFA stenosis or occlusion in 205 limbs underwent stent implantation in the SFA at a single center. Stent fractures were determined by radiography and classified into types I through V. Loss of patency was assessed by duplex ultrasonography (>2.4 peak systolic velocity ratio) or angiography (percent diameter stenosis >50%). Results: The 12- and 24-month primary patency rates were 49.8% and 43.4%, respectively. Stent fractures occurred in 12.5% and 26.8% per limb (6.6% and 19.4% per stent) at 12 and 24 months, respectively. Primary patency was numerically worse in the stent fracture group but not statistically different from the group without fractures at 2 years. Primary patency for different classes of stent fracture were 30.8% (type I), 50.0% (type II), and 31.3% (type III–V). Hyperlipidemia (p=0.001), TransAtlantic Inter-Society Consensus II classification (p=0.007), chronic total occlusion (CTO; p<0.001), proximal lesion location (p=0.008), lesion calcification (p=0.025), total stent length (p=0.005), stent diameter (p=0.001), and number of stents (p=0.001) were statistically significant predictors of stent fracture. Multivariate analysis showed that CTO (hazard ratio 0.173, 95% confidence interval 0.042 to 0.716, p=0.015) was an independent predictor of stent fracture. Conclusion: Stent fractures occur more frequently in patients with CTOs after treatment of longer stented lesions. Although multivariate analysis showed that CTO was the only independent predictor regardless of stent length or number, the stent fracture rate was numerically higher in the severe calcification and proximal SFA lesion subgroups. Stent fracture did not appear to affect long-term patency rates, but this is yet to be confirmed with further follow-up.

Duplex Ultrasound Assessment of Native Stenoses in the Superficial Femoral and Popliteal Arteries

Purpose: To evaluate duplex ultrasonography (DUS) in the assessment of femoropopliteal stenoses comparing a single native stenosis (SNS) to multisegmental native stenoses (MNS). Methods: Among the 1284 patients treated for atherosclerotic occlusive disease involving the femoropopliteal segment between November 2002 and November 2012, 139 patients (97 men; mean age 68±8 years) with 142 SNS or 143 MNS in 79 and 60 patients, respectively, were eligible for this retrospective analysis. The peak systolic velocity ratios with proximal (PSVRprox) and distal (PSVRdist) reference for the 285 lesions were compared with their respective angiographic stenosis grade as measured by 2 independent readers using quantitative vascular analysis to ensure objectivity. Receiver operating characteristic curve analysis was used to evaluate sensitivity, specificity, and the optimal thresholds of PSV and PSVR for detection of stenoses by grade (>50%, >70%, or >80% diameter stenosis). The area under the curve (AUC) values of dependent and independent receiver operating characteristic curves were compared. Results: For SNS, correlation of PSVRprox to diameter stenosis (R=0.88) was higher (p<0.001) than the correlation for MNS (R=0.78). In the SNS group, the AUC for detecting a >50% (0.99±0.01), >70% (0.98±0.01), and >80% (0.96±0.01) stenosis with PSVRprox was significantly higher than in the MNS group [AUC50% 0.93±0.02 (p=0.01), AUC70% 0.92±0.02 (p=0.02), and AUC80% 0.87±0.03 (p=0.003)]. The optimal thresholds for detecting >50%, >70%, and >80% stenoses for SNS using PSVRprox were 2.6, 3.3, and 3.9, respectively. For MNS, the optimal thresholds of PSVRprox were 2.6, 3.4, and 3.9, respectively, with respective sensitivities of 87%, 81%, and 75%; respective specificities of 93%, 90%, and 82%; negative predictive values of 45%, 64%, and 74%; and positive predictive values of 99%, 95%, and 83%. Conclusion: DUS is an optimal tool for quantification of SNS. However, a multisegment setting has a significant negative impact on the quantification of femoropopliteal artery stenosis.

Optimal Ultrasound Criteria for Defining the Severity of Vertebral Artery in-Stent Restenosis

The aim of the study described here was to establish ultrasound criteria for defining the severity of vertebral artery in-stent restenosis. A total of 197 patients with vertebral artery stents were enrolled in this study. Color Doppler ultrasonography was performed after stenting. Peak systolic velocity and end-diastolic velocity within the stent (PSVstent, EDVstent) and at the intervertebral segments were recorded. The ratio of the PSV at the origin to that at the intervertebral segment was calculated. With digital subtraction angiography as the reference standard, the optimal cutoff values of hemodynamic parameters identifying 50%–69% and 70%–99% restenosis were determined by receiver operating characteristic analysis. The optimal cutoff values of hemodynamic parameters identifying 50%–69% restenosis were PSVstent ≥ 170 cm/s, EDVstent ≥45 cm/s and PSV ratio ≥2.7, and those for 70%–99% restenosis were PSVstent ≥220 cm/s, EDVstent ≥55 cm/s and PSV ratio ≥4.2. In conclusion, color Doppler ultrasonography is a reliable method for monitoring patients with avertebral artery stents.

Common Carotid Artery Peak-Systolic Velocity Ratio Predicts High-Grade Common Carotid Stenosis

Screening for common carotid artery (CCA) stenosis with duplex ultrasound (DUS) velocity criteria alone can be limited due to within-patient and between-patients hemodynamic variability. This study evaluated inter-CCA velocity ratio criteria to predict high-grade CCA stenosis. Retrospective review of consecutive patients who underwent computed tomography angiography (CTA) and DUS peak-systolic velocity (PSV) measurements of bilateral CCA, independently recorded, between 2008 and 2014. Patients with dampened CCA waveforms on DUS, readily indicating high-grade proximal stenosis, consistuted group B. The remainder without dampened waveforms constituted group A. Inter-CCA PSV ratios were calculated by dividing the higher CCA PSV to the lower one of the other side, so the ratios would always be >1. Ratios were subsequently paired with each respective unilateral CCA diameter stenosis (uDS) and differential bilateral CCA diameter stenosis (dDS). A quadratic regression model was fitted to predict uDS and dDS. Receiver operating characteristic curves were used to determine optimal ratios for ≥50% CCA stenosis. The study excluded patients with carotid artery occlusion. From 174 patients, 167 patients were included in group A and seven in group B. In group A, 31 patients had ≥50% uDS and 17 had ≥50% dDS. All stenoses ≥50% were identified on the same side with the higher PSV. Inter-CCA PSV ratio predicted ≥50% uDS (r2 = 0.57; P < .0001) and dDS (r2 = 0.75; P < .0001; Fig). In group B, all patients had ≥60% stenosis that involved the vessel origin. An increasing inter-CCA PSV ratio showed a trend toward contralateral high-grade stenosis (r2 = .54, P = .06). Receiver operating characteristic curves for ≥50% uDS showed an optimal threshold CCA ratio ≥1.96 with 93% accuracy, 75% sensitivity, and 97% specificity (area under curve, 0.857; 95% confidence interval, 0.755-0.958) and for ≥50% a dDS ratio ≥2.62 with 97% accuracy, 82% sensitivity, and 99% specificity (area under curve, 0.938; 95% confidence interval, 0.828-1.0). DUS-based CCA PSV ratio can accurately predict unilateral and differential high-grade CCA stenosis. Also, in patients with dampened waveforms, it implied contralateral severe proximal stenosis. This parameter should be further validated in prospective studies and is a promising adjunct screening tool to detect high-grade common carotid stenosis.

Doppler Ultrasonography of Carotid Arteries: Velocity Criteria Validated by Arteriography

Results: The patients’ average age was 69 years, 47 (64%) men, 27 (37%) with cerebrovascular accident, and 13 (18%), transient ischemic attack. The best criterion for stenoses of 50% 69% was ICA PSV ≥ 141 cm/s (sensitivity: 94%, specificity: 90%, accuracy: 93%) (AUC 0.97). For stenoses between 70% 99%, ICA PSV ≥ 176 cm/s presented sensitivity: 92%; specificity: 87%; accuracy: 90%; ICA PSV ≥ 230 cm/s presented sensitivity: 89%; specificity: 89%; accuracy: 89% (AUC 0.96); and ICA/CCA PSV ratio ≥ 4.0 presented sensitivity: 70%; specificity: 100%; and accuracy: 81% (AUC 0.96). Six ICA occlusions were detected by DU and arteriography. The DU and arteriography correlation was: PSV (0.81 – p < 0.001); EDV (0.78 – p < 0.001) and ICA/CCA PSV ratio (0.81 – p < 0.001).

Duplex Ultrasonography and its Use in Surveillance Post-EVAR

After endovascular aortic aneurysm repair (EVAR), patients require annual surveillance with either CT scan or duplex ultrasonography (DU). These studies should be used to identify patients who require reintervention for EVAR complications. DU, a less expensive and radiation free option, has been shown to accurately predict aneurysm sac size and endoleak. In addition, using criteria of PSV<300 cm/s and PSV ratio <3.5, DU can rule out limb stenosis. After a normal post-procedure DU, only 2.2% of patients require reintervention within the first 3 years suggesting that less frequent follow-up may be utilized. DU is an important tool in the surveillance of EVAR patients.

Abstract 16152: Utility of Peak Systolic Velocity Ratio in Asymptomatic Patients With Restenosis After Endovascular Therapy for Femoro-Popliteal Lesion

Introduction: The predictive factor of whether asymptomatic restenosis needs reintervention after initial therapy remains unclear. Objective: The aim of this study was to evaluate whether peak systolic velocity ratio (PSVR) is effective to predict target lesion revascularization (TLR) after endovascular therapy (EVT) for femoropopliteal (FP) lesion. Methods: From April 2007 to September 2013, 120 restenotic limbs without ischemic symptoms (mean age: 73.1±9.0, men: 75.0%, stent implantation: 57.5%) were selected and analyzed, 73 limbs underwent reintervention. Median follow-up period was 33.7 months (5.1-110.4 months). They were followed by serial duplex ultrasound (DUS). Restenosis was defined as peak systolic velocity (PSV) &gt; 250cm/s or PSVR &gt; 2.4 by using DUS. We divided them into two groups (High PSVR group (PSVR ≧3.63)and low PSVR group (PSVR &lt; 3.63)). The ratio of TLR was compared between two groups by Kaplan-Meier survival curve. We also analyzed the TLR between balloon angioplasty (POBA) alone and stent implantation on initial EVT. Each cut off value of PSVR were 4.19 and 3.63. Results: At 1, 3 and 5 years after initial EVT, Freedom from TLR were significantly different between two groups (76.5%, 33.2% and 18.3% vs 90.7%, 75.4%, and 58.0%, p&lt;0.001). Moreover, two groups were significantly different when analyzed about limbs performed POBA (86.9%, 67.0% and 35.7% vs 69.2%, 29.0% and 14.5%, p =0.048 ) and stenting on initial EVT (92.3%, 77.6% and 51.7% vs 83.8%, 35.2% and 12.0%, p &lt; 0.01). After adjustment for use of cilostazol, use of proton pomp inhibitor , chronic total occlusion, history of EVT for aortoiliac disease, PSVR was an independent predictors of TLR. Conclusions: PSVR may be a predictive factor of performing reintervention for asymptomatic patient with restenosis after EVT of FP lesion.

S.M.A.R.T. Self-Expanding Nitinol Stent for the Treatment of Atherosclerotic Lesions in the Superficial Femoral Artery (STROLL): 1-Year Outcomes

PurposeTo assess safety and efficacy of the S.M.A.R.T. Vascular Stent System (Cordis Corp, Fremont, California) in obstructive superficial femoral artery (SFA) disease. Materials and MethodsThe single-arm, multicenter STROLL study (S.M.A.R.T. Nitinol Self-Expanding Stent in the Treatment of Obstructive Superficial Femoral Artery Disease) included 250 patients (250 lesions in SFA or proximal popliteal artery). The efficacy endpoint was primary patency defined by freedom from binary restenosis (peak systolic velocity ratio > 2.5) as derived by duplex ultrasound plus clinically driven target lesion revascularization (TLR) at 12 months. ResultsMean age of patients was 67.7 years ± 10.3; 47.2% of patients had diabetes; distribution of Rutherford/Becker classes 2, 3, and 4 was 45.8%, 51.4%, and 2.8%. Mean lesion length and reference vessel diameter were 77.3 mm ± 35.3 and 4.9 mm ± 0.7, respectively (23.6% cases with total occlusions). The 30-day freedom from major adverse events (death, index limb amputation, clinically driven TLR) was 100%. The 1-year primary patency was 81.7% by Kaplan-Meier estimate. The presence of diabetes or total occlusion had no effect on primary patency. Ankle-brachial index was 0.4–0.8 in 84.6% of patients at baseline and improved to > 0.8 in 81.0% of patients at 12 months. The proportion of patients in Rutherford/Becker class 3–4 was reduced from 54.2% at baseline to 8.0% at 12 months. Four patients (2.0%) experienced single-stent strut fracture (type I) at 1 year, without associated loss of stent patency. ConclusionsThe S.M.A.R.T. Vascular Stent System proved to be safe and effective for endovascular treatment of obstructive SFA and proximal popliteal artery disease, based on 1-year vessel patency and associated hemodynamic and clinical improvements.

Chronic perfusion changes and reduction in preeclampsia incidence in pregnant smokers: an ophthalmic artery Doppler study

Objective: Our aim was to investigate the hemodynamic profile of the ophthalmic artery in preeclamptic women, pregnant smokers and pregnant controls with no known diseases. Study design: A prospective cross-sectional study using the performed ophthalmic artery Doppler ultrasonography in 20 mild preeclamptic women and 20 severe preeclamptic women, 37 pregnant smokers and 51 controls. Data evaluated by using Doppler ultrasonography were as follows: resistance index, pulsatility index, peak systolic velocity, end diastolic velocity, second peak systolic velocity and peak ratio. The Doppler results, gestational age, patient age and systolic and diastolic pressure of groups were subjected to analysis of variance (p < 0.05). Results: Both groups of preeclamptic women presented significant orbital hyperperfusion (resistance index: 0.64 ± 0.07 and 0.64 ± 0.13, pulsatility index:1.10 ± 0.26 and 1.02 ± 0.30, end diastolic velocity:14.13 ± 4.44 and 15.66 ± 4.17), whereas pregnant smokers showed vasospasm (0.84 ± 0.04, 2.27 ± 0.43, 4.78 ± 1.28, respectively) indicating divergent vascular pattern between these two groups (p < 0.01) and differences between each group and controls (0.78 ± 0.06, 1.89 ± 0.36, 7.43 ± 2.71), respectively, p < 0.01. Peak systolic velocity mean values for severe preeclamptic women was 40.36 ± 5.61 cm/s, significantly higher than in all groups (34.53 ± 6.82 cm/s, 31.03 ± 4.72 cm/s and 34.35 ± 6.43 cm/s). Conclusion: Preeclamptic women have presented hyperperfusion whereas chronic smokers have shown hypoperfusion in ophthalmic artery. Thus, chronic flow changes in pregnant smokers might reduce the number of sudden and catastrophic events in preeclampsia.

The Effect of a Simulation Training Package on Skill Acquisition for Duplex Arterial Stenosis Detection

In vascular surgery, duplex ultrasonography is a valuable diagnostic tool in patients with peripheral vascular disease, and there is increasing demand for vascular surgeons to be able to perform duplex scanning. This study evaluates the role of a novel simulation training package on vascular ultrasound (US) skill acquisition. A total of 19 novices measured predefined stenosis in a simulated pulsatile vessel using both peak systolic velocity ratio (PSVR) and diameter reduction (DR) methods before and after a short period of training using a simulated training package. The training package consisted of a simulated pulsatile vessel phantom, a set of instructional videos, duplex ultrasound objective structured assessment of technical skills (DUOSATS) tool, and a portable US scanner. Quantitative metrics (procedure time, percentage error using PSVR and DR methods, DUOSAT scores, and global rating scores) before and after training were compared. Subjects spent a median time of 144 mins (IQR: 60-195) training using the simulation package. Subjects exhibited statistically significant improvements when comparing pretraining and posttraining DUOSAT scores (pretraining = 17 [16-19.3] vs posttraining = 30 [27.8-31.8]; p < 0.01), global rating score (pretraining = 1 [1-2] vs posttraining = 4 [3.8-4]; p < 0.01), percentage error using both the DR (pretraining = 12.6% [9-29.6] vs posttraining = 10.3% [8.9-11.1]; p = 0.03) and PSVR (pretraining = 60% [40-60] vs posttraining = 20% [6.7-20]; p < 0.01) methods. In this study, subjects with no previous practical US experience developed the ability to both acquire and interpret arterial duplex images in a pulsatile simulated phantom following a short period of goal direct training using a simulation training package. A simulation training package may be a valuable tool for integration into a vascular training program. However, further work is needed to explore whether these newly attained skills are translated into clinical assessment.

Duplex ultrasound diagnosis of failing stent grafts placed for occlusive disease

We previously showed that duplex ultrasound (DU) imaging is beneficial in the diagnosis of failing vein and prosthetic grafts performed for arterial occlusive disease. The purpose of this study was to evaluate whether DU imaging can reliably diagnose failing stent grafts (ie, covered stents) placed for arterial occlusive disease. Between July 1, 2005, and June 30, 2013, we placed 142 stent grafts in 92 arterial segments (1.5 stent grafts/stenotic artery) for lower extremity occlusive disease in patients who also underwent at least one DU surveillance study documenting a patent stent graft. Stent grafts were placed in 29 iliac and 52 femoropopliteal arteries and in 11 failing infrainguinal bypass grafts. Stent grafts used were Viabahn (W. L. Gore and Associates Inc, Flagstaff, Ariz) in 116 (82%), Wallgraft (Boston Scientific, Natick, Mass) in 23 (16%), Fluency (C. R. Bard Inc, Tempe, Ariz) in 2 (1%), and iCast (Atrium, Hudson, NH) in 1 (1%). Mean follow-up was 16 months (range, 1 week-86 months). Postoperative DU surveillance was performed in our Intersocietal Accreditation Commission accredited noninvasive vascular laboratory at 1 week, then every 3 months the first year, and every 6 months thereafter. DU measured peak systolic velocities (PSVs) and velocity ratio of adjacent PSVs (Vr) every 5 cm within the stent graft and adjacent arteries. We retrospectively classified the following factors as "abnormal DU findings:" focal PSVs >300 cm/s, uniform PSVs <50 cm/s throughout the graft, and a Vr >3.0. Fifteen of 20 patients with one or more of these abnormal DU findings underwent prophylactic intervention (n = 8) or occluded without intervention (n = 7), whereas only two of 72 with normal DU findings occluded (P = .0001). Excluding the eight patients who underwent prophylactic intervention, seven of 12 patients with abnormal DU findings occluded without intervention vs two of 72 with normal DU findings (P = .0001). These findings suggest that follow-up DU surveillance can predict failure of stent grafts placed for lower extremity occlusive disease. Focal PSVs >300 cm/s, Vr >3.0, and most importantly, uniform PSVs <50 cm/s throughout the stent graft were statistically reliable markers for predicting stent graft thrombosis.

The Revised Sonographic NASCET Index: A New Hemodynamic Parameter for the Assessment of Internal Carotid Artery Stenosis.

A previously described Doppler parameter, the sonographic NASCET index (SNI), was derived to be more directly analogous to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methodology for assessing carotid artery stenosis. However, this index does not account for complex changes affecting the Doppler waveform. We propose a revised SNI (rSNI) in an effort to improve predicting carotid stenosis. 25 carotid bifurcations with stenoses ranging from 40 - 92 % were analyzed. For each vessel, the rSNI and original SNI were calculated. The peak systolic velocity (PSV), rSNI, and original SNI were correlated with angiography using linear regression analysis and relative accuracies were compared at two thresholds. A correlation between rSNI and angiography was found to be significantly better than that between PSV or internal carotid artery-common carotid artery (ICA-CCA) peak velocity ratio and angiography (r² = 0.47 vs. 0.22; r² = 0.47 vs. 0.16). The accuracy of PSV in predicting high-grade stenosis was 68% and 72%, compared with 80% and 88% for rSNI, at each of two thresholds. The original SNI better correlated with angiography compared to the rSNI (r² = 0.55 vs. 0.47), but with slightly lower accuracy in predicting high-grade stenosis (76% vs. 80%). The revised SNI correlates more closely with angiographic stenosis than either the PSV or the ICA-CCA ratio, and is more accurate in predicting high-grade stenosis. However, it is overall comparable to the original SNI, suggesting that the previously unaccounted for effects over the remainder of the cardiac cycle do not significantly improve the ability to sonographically predict significant stenosis.

Umbilical and fetal middle cerebral artery Doppler reference ranges in a twin population followed longitudinally from 24 to 38 weeks' gestation

To construct monochorionic diamniotic (MCDA) and dichorionic diamniotic (DCDA) twin reference ranges for umbilical artery (UA) pulsatility index (PI), UA resistance index (RI), fetal middle cerebral artery (MCA) PI and peak systolic velocity (PSV) and cerebroplacental ratio (CPR) from 24 weeks' to 38 weeks' gestation and compare these with published normal values for singleton pregnancies. This prospective multicenter cohort study included 1028 unselected twin pairs recruited over a 2-year period. Participants with dichorionic twins underwent fortnightly ultrasound surveillance from 24 weeks' gestation, with monochorionic twins being followed every 2 weeks from 16 weeks until delivery. A total of 7536 fetal Doppler examinations in 618 twin pregnancies were included in the analysis, with reference ranges for MCDA and DCDA pregnancies constructed for each of the Doppler indices using multilevel modeling. UA-PI and UA-RI appear to be higher in twins than in singletons, and MCA-PI and MCA-PSV appear to be lower. The CPR also appears to be lower in twins than in singletons. Similar MCA indices were observed in MCDA and DCDA twins. We have established longitudinal reference ranges for UA-PI and UA-RI, MCA-PI and MCA-PSV and CPR in twin pregnancies, which appear to differ from those in singleton pregnancies. The derived twin-specific reference ranges may be more appropriate in the surveillance of these high-risk pregnancies. Applying the singleton CPR cut-off of ≤ 1.0 may lead to a large number of false-positive diagnoses of cerebral redistribution in twin fetuses.

Drug-Coated Balloons vs. Drug-Eluting Stents for Treatment of Long Femoropopliteal Lesions

To compare the performance of drug-coated balloons (DCB) and drug-eluting stents (DES) in long femoropopliteal lesions. A retrospective dual center study included 228 patients (139 men; median age 69 years) with femoropopliteal lesions ≥10 cm suffering from peripheral artery disease (Rutherford categories 1-5) treated either with DCB or DES. Propensity score stratification was used to minimize bias. The 131 DCB patients (77 men; mean age 68.9±10.5 years) had a mean lesion length of 194.4±86.3 mm (range 100-450), while the 97 DES patients (62 men; mean age 68.2±8.0 years) had lesions averaging 195.0±64.5 mm (range 100-350) in length. Restenotic lesions were treated in 68 (51.9%) DCB patients and 43 (44.3%) DES patients; over half the lesions in both groups were total occlusions [DCB: 69 (52.7%), DES: 61 (62.9%)]. Outcome measures were patency (peak systolic velocity ratio <2.4), clinically driven target lesion revascularization (TLR), event-free survival, and freedom from worsening of Rutherford classification by ≥2 categories. In the DCB cohort, provisional stent placement was performed in 24 (18.3%) lesions for refractory stenosis (5, 3.8%), flow-limiting dissection (13, 9.9%), and other reasons (6, 4.6%). There was no procedure-related mortality in either cohort. The binary restenosis rates were 23.9% (26/109) and 30.4% (24/79, p=0.319) in the DCB and DES cohorts, respectively, and clinically driven TLR rates were 15.6% (17/109) vs. 19.0% (15/79, p=0.543), respectively. Estimates for freedom from clinically driven TLR and event-free survival were not different between the study cohorts nor were outcomes regarding the ankle-brachial index and Rutherford category. DCB and DES perform equally well in the endovascular treatment of femoropopliteal lesions ≥10 cm and better than traditional endovascular treatment. In a real world setting of TASC C and D lesions, the provisional stent rate in the DCB cohort is low.

A novel technique to predict pulmonary capillary wedge pressure utilizing central venous pressure and tissue Doppler tricuspid/mitral annular velocities.

Assessing left ventricular (LV) filling pressure (pulmonary capillary wedge pressure, PCWP) is an important aspect in the care of patients with heart failure (HF). Physicians rely on right ventricular (RV) filling pressures such as central venous pressure (CVP) to predict PCWP, assuming concordance between CVP and PCWP. However, the use of this method is limited because discordance between CVP and PCWP is observed. We hypothesized that PCWP can be reliably predicted by CVP corrected by the relationship between RV and LV function, provided by the ratio of tissue Doppler peak systolic velocity of tricuspid annulus (S(T)) to that of mitral annulus (S(M)) (corrected CVP:CVP·S(T)/S(M)). In 16 anesthetized closed-chest dogs, S T and S M were measured by transthoracic tissue Doppler echocardiography. PCWP was varied over a wide range (1.8-40.0 mmHg) under normal condition and various types of acute and chronic HF. A significantly stronger linear correlation was observed between CVP·S(T)/S(M) and PCWP (R2 = 0.78) than between CVP and PCWP (R2 = 0.22) (P < 0.01). Receiver-operating characteristic (ROC) analysis indicated that CVP·S(T)/S(M) >10.5 mmHg predicted PCWP >18 mmHg with 85% sensitivity and 88% specificity. Area under ROC curve for CVP·S T/S M to predict PCWP >18 mmHg was 0.93, which was significantly larger than that for CVP (0.66) (P < 0.01). Peripheral venous pressure (PVP) corrected by S T/S M (PVP·S(T)/S(M) also predicted PCWP reasonably well, suggesting that PVP·S(T)/S (M) may be a minimally invasive alternative to CVP·S(T)/S(M) In conclusion, our technique is potentially useful for the reliable prediction of PCWP in HF patients.