PubMed Health⌕ Search

Biomedical subjects

Dink A Legemate

Publications and source records attributed to Dink A Legemate.

9 recordsLinked to original sources
PubMed2004

Contrast-enhanced duplex scanning of crural arteries by means of continuous infusion of Levovist.

OBJECTIVES: To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for distal bypass graft surgery. DESIGN, PATIENTS, AND METHODS: The study design consisted of two parts. Part 1 investigated the color and spectral Doppler scan enhancement of three different Levovist dosages (200, 300, and 400 mg/mL) in one arterial segment of a patent lumen of a crural artery in seven patients with PAOD. Part 2 investigated the value of the optimum Levovist dosage in the assessment of 10 crural arteries in 10 consecutive patients with PAOD. Angiography was the reference standard. RESULTS: Part 1: Levovist significantly enhanced color and spectral Doppler scan as compared with baseline ultrasound scan, but no differences were found between the Levovist dosages. Thus, the lowest Levovist dosage sufficed for application in part 2, because of its infusion volume and prolonged enhancement time. Part 2: The agreement between contrast-enhanced duplex scanning and angiography was moderate (kappa = 0.50; 95% confidence interval [CI], 0.03-0.97). Five (50%) of 10 crural arteries that could not adequately be visualized with routine duplex scanning could be visualized with contrast-enhanced duplex scanning. CONCLUSION: Contrast-enhanced duplex scanning by means of continuous infusion of Levovist in patients with PAOD improves the ultrasound scan investigation of crural arteries in case routine duplex scanning is inconclusive and might reduce the need for angiography.

Aged↗
PubMed2003

Evaluation of toe pressure and transcutaneous oxygen measurements in management of chronic critical leg ischemia: a diagnostic randomized clinical trial.

OBJECTIVE: The definition of critical limb ischemia (CLI) requiring vascular intervention is still under debate. The clinical eye of the physician and ankle blood pressure measurements used so far may fall short in appreciation of the severity of disease, which makes decision-making for a vascular intervention subjective. In previous studies two simple functional tests, ie, transcutaneous oxygen pressure (tcPo(2)) and toe blood pressure (TP) measurements, provided reliable information about the need for vascular intervention. Therefore we evaluated the diagnostic value of tcPo(2) and TP in management of clinically suspected critical leg ischemia. Study design This was a diagnostic randomized controlled clinical trial. Subjects were ambulatory and hospitalized patients in a referral university hospital. METHODS: Ninety-six patients (128 legs) with clinically suspected critical limb ischemia were referred to the vascular laboratory for routine investigation. Two diagnostic management strategies were compared: conventional strategy, ie, clinical judgment and ankle pressure determined the diagnostic and therapeutic approach, and a new strategy in which tcPo(2) and TP determined the diagnostic and therapeutic approach. Main outcome measures included clinical outcome, defined as pain relief, wound healing, and limb survival. RESULTS: At 18-month follow-up, 26 of 62 legs treated with the conventional approach and 28 of 66 legs treated with the new approach were treated conservatively. The new method did not score significantly different from the conventional method insofar as clinical outcome: pain score, 50 versus 48; number of amputations, 8 versus 10; and number of deaths, 11 versus 8 deaths, respectively. CONCLUSION: Two simple objective diagnostic tests, TP and tcPo(2), did not improve clinical outcome when incorporated into routine management of suspected critical limb ischemia. Nevertheless, these techniques might still be helpful for physicians less experienced with treating critical limb ischemia and who are in doubt regarding the need for vascular intervention.

Aged↗
PubMed2003

Effect of beta-blockers on peripheral skin microcirculation in hypertension and peripheral vascular disease.

OBJECTIVE: This study was undertaken to investigate the possible negative effect of beta-blockers on skin microcirculation in patients with intermittent claudication and hypertension. Methods and materials In this clinical crossover study, 20 patients with mild to moderate hypertension, treated with long-term beta-blockade, and intermittent claudication or ischemic rest pain, underwent assessment of peripheral circulation before and after 2-week withdrawal of beta-blocking therapy and again 2 weeks after restarting therapy. Replacement therapy (calcium antagonist) was given if considered necessary to control hypertension. Skin microcirculation was assessed with three noninvasive techniques: capillary microscopy of the hallux nailfold, transcutaneous oximetry of the forefoot, and laser Doppler fluxmetry of the great toe. RESULTS: Mean initial blood pressure was 163/81 mm Hg. Mean heart rate significantly increased with withdrawal of beta-blocker, from 65 bpm to 85 bpm. No significant differences in skin microcirculation and blood pressure were found between measurements obtained before, during, and after withdrawal of beta-blocking therapy. Patients experienced no change in symptoms during the study. CONCLUSION: beta-Blockers do not appear to have a negative effect on peripheral skin microcirculation and are therefore not contraindicated to treat hypertension when intermittent claudication or ischemic rest pain is also present.

Adrenergic beta-Antagonists↗
PubMed2003

Design of the START-trial: STimulation of ARTeriogenesis using subcutaneous application of GM-CSF as a new treatment for peripheral vascular disease. A randomized, double-blind, placebo-controlled trial.

Peripheral arterial disease (PAD) affects a large percentage of the elderly population. Standard invasive treatment, apart from risk factor modulation, consists of bypass surgery or percutaneous transluminal angioplasty. However, symptomatic recurrence rates are high for both procedures and a substantial part of the patient population with PAD is not a candidate for invasive revascularization due to complexity of the lesion and/or co-morbidity. Therapeutic arteriogenesis has been proposed as an alternative treatment option. The present paper describes the design of the START-trial. This trial aims to determine the potential of the pro-arteriogenic substance granulocyte/macrophage colony stimulating factor (GM-CSF) to increase maximal walking distance in patients with intermittent claudication. A double-blinded, randomized, placebo-controlled study will be performed in 40 patients with peripheral obstructive arterial disease Rutherford grade I, category 2 or 3, that are candidates for bypass surgery or percutaneous transluminal angioplasty. Based on pharmacokinetic and toxicologic studies, a dose of 10 microg/kg will be used. Patients will be treated for a period of 14 days on each consecutive day, with the last injection applied on day 12. The primary endpoint will be the change in walking distance from day 0 to day 14 as assessed by an exercise treadmill test. Secondary endpoints will be the ankle-brachial index at rest and after exercise, the pain-free walking distance and cutaneous microcirculatory alterations as assessed by laser Doppler fluxmetry. Iliac flow reserve and conductance will be measured by magnetic resonance imaging.

Arterial Occlusive Diseases↗
PubMed2003

Assessment of the collateral function of the circle of Willis: three-dimensional time-of-flight MR angiography compared with transcranial color-coded duplex sonography.

BACKGROUND AND PURPOSE: Identification of the intracranial collaterals assists in identifying patients with severe occlusive disease of the internal carotid arteries who are at lower risk of transient ischemic attacks (TIAs) and stroke. We investigated the usefulness of MR angiography in identifying functional collaterals of the circle of Willis. METHODS: MR angiography of the circle of Willis was performed in 50 healthy volunteers. Visibility was used as the criterion to define the intracranial collaterals as being functional. Two observers independently assessed the MR angiograms. Results were compared with those of transcranial color duplex sonography (TCCD), and results of carotid compression tests were the standard of reference for the identification of functional intracranial collaterals. RESULTS: With MR angiograms, reviewer 1 achieved a sensitivity of 85%, a specificity of 81%, a positive predictive value of 95%, and a negative predictive value of 55%. Reviewer 2 achieved a sensitivity of 87%, a specificity of 67%, a positive predictive value of 92%, and a negative predictive value of 53%. Interobserver agreement on MR angiograms was moderate (kappa = 0.57, 95% confidence interval: 0.42, 0.72). CONCLUSION: Visible collaterals of the circle of Willis on MR angiograms are able to supply collateral flow in the presence of carotid artery obstruction. However, the low negative predictive value of MR angiography indicates that, if collaterals are not visible, supplementary TCCD investigation is required.

Adult↗
PubMed2002

Color-flow duplex scanning of the leg arteries by use of a new echo-enhancing agent.

OBJECTIVE: This was a dose-finding and effectiveness study of a newly developed contrast-enhancing agent, sulphur hexafluoride (SF(6)), in patients with peripheral arterial disease in whom the therapeutic policy could not be established on the basis of standard color-flow duplex scanning of the leg arteries. METHODS: In this open-label, randomized, dose-ranging, crossover design, 14 patients in whom the assessment of vessel patency was difficult because of poor visibility (low-flow state) or extensive wall calcifications were studied. Contrast-enhanced duplex scanning was performed on the upper leg (n = 4), lower leg (n = 6), or pedal (n = 4) arteries after intravenous injection of four different dosages of SF(6). The results were compared with those from selective angiography of the vessel of interest. Contrast duration and agreement about the diagnosis and the confidence in the diagnosis were obtained before and after administration of the contrast agent. RESULTS: No adverse effects of the contrast agent were seen. Overall agreement was reasonable with regard to vessel patency between contrast-enhanced duplex scanning and angiography (71%). Nine of 14 vessels (64%) appeared open when contrast was applied. In four cases this could not be confirmed by angiography; in two of these cases this was due to the presence of collateral vessels. All vessels that appeared occluded with the contrast agent were also occluded on the angiogram. The confidence in the diagnosis increased from 56% to 91% after contrast administration (P <.0001). CONCLUSION: SF(6)-enhanced color-flow duplex scanning is a safe method that may improve the assessment of the patency of leg arteries, particularly in low-flow states. The visualization of collateral vessles during (enhanced) duplex scanning may be misleading because they may be regarded as the vessel of interest.

Aged↗
PubMed2002

Improved assessment of the hemodynamic significance of borderline iliac stenoses with use of hyperemic duplex scanning.

OBJECTIVE: To improve the assessment of the hemodynamic significance of borderline iliac stenoses (stenosis with a peak systolic velocity [PSV] ratio between 1.5 and 3.5) by means of hyperemic duplex scanning. The duplex ultrasound parameter-absolute increase in PSV across the stenosis after exercise (Delta PSV(e))-was studied prospectively. PATIENTS AND METHODS: Fifty-eight legs in 53 consecutive patients with symptomatic arterial obstructive disease with borderline iliac stenosis were studied prospectively. Ultrasound velocity data collected after exercise on a bicycle ergometer at 2 W/kg during 2 minutes were judged against the assessment of the hemodynamic significance by means of intraarterial pressure measurement, before and after the administration of 50 mg papaverine. RESULTS: On the basis of receiver operating characteristic curves traced for 43 iliac stenoses in 39 patients who finished the exercise, Delta PSV(e) > or = 1.4 m/s had optimal sensitivity of 93% (95% confidence interval [CI],.77-.99), specificity of 87% (95% CI,.60-.98), positive predictive value of 93% (95% CI,.77-.99) and negative predictive value of 87% (95% CI,.60-.98). CONCLUSIONS: The results of this study show that Delta PSV(e) with a cutoff value of 1.4 m/s in combination with the PSV ratio improves the assessment of the hemodynamic significance of borderline iliac artery stenoses if the patient can accomplish the workload.

Adult↗