Carsten Ranke

Duplex scanning of the peripheral arteries: correlation of the peak velocity ratio with angiographic diameter reduction.

The correlation of the peak systolic velocity (PSV) and the peak velocity ratio (PVR, calculated as intrastenotic PSV divided by proximally recorded PSV) with percent diameter reduction was studied in 62 patients with peripheral arterial occlusive disease. PSV values correlated well with angiographic diameter reduction (r = 0.81, n = 106 stenoses), but due to large variability the sensitivity and specificity in the detection of greater than 50% stenoses were only 66% and 80% (for a cutoff value of 180 cm/s). The PVR showed less interindividual variability and exhibited a strong correlation with percent diameter reduction (r = 0.93,n = 106 stenoses). A 2.4 fold increase of the peak systolic velocity values with respect to the proximal site (i.e., PVR = 2.4) or more indicated a more than 50% stenosis with a sensitivity of 87% and a specificity of 94%. Figures for PVR are provided to quantitate the degree of stenoses in the 50-99% range. Calculation of PVR may normalize for patient variation and allow noninvasive quantification of lumen narrowing with high sensitivity and specificity.

Dose-dependent effect of aspirin on carotid atherosclerosis.

BackgroundAntiplatelet treatment with aspirin is well established as secondary prophylaxis after a transient ischemic attack or minor ischemic stroke, but the effect of aspirin treatment on the course of carotid atherosclerosis is unknown. We investigated the effect of aspirin on the initial stages of carotid atherosclerosis Methods and ResultsPatients were recruited from a prospective, randomized, double-blind clinical trial to compare two doses of aspirin (900 mg versus 50 mg daily) with regard to restenoses after lower limb angioplasty. Of the 383 patients admitted to the angioplasty trial, 27 patients with 104 small carotid atheroma (<50% lumen narrowing) were examined at entry and after 1 year of aspirin treatment with the use of a high-resolution ultrasound duplex system. Disease progression and regression were defined by a change of maximal plaque area (as measured by longitudinal ultrasound sections) of more than 2 SDs of the method. The change in plaque area was significantly different for the treatment groups: Average plaque size remained unchanged after treatment with 900 mg aspirin daily but increased markedly after treatment with 50 mg aspirin daily (p=0.011). There were significantly more lesions in the 50-mg group showing progression than in the 900-mg group (23 plaques [47%] versus 13 plaques [24%], p=0.025). Ultrasonic disappearance of a lesion was observed only in the 900-mg group in nine cases (seven soft plaques and two ulcerative plaques, p=0.018). The six patients on 50 mg aspirin who continued smoking during the study showed significantly more progression compared with the seven nonsmokers in the 50-mg group (17 plaques [59%] versus six plaques [30%], p=0.038). ConclusionThe results of our study indicate that aspirin treatment slows carotid plaque growth in a dose-dependent fashion, with a dose of 900 mg daily more efficient than 50 mg daily.

Pseudoaneurysma mit daraus hervorgehender AV-Fistel nach transfemoraler Punktion

Zusammenfassung□ HintergrundLokale Gefäßkomplikationen treten nach transfemoraler Herzkatheteruntersuchung in einer Häufigkeit von etwa 5% auf, wobei es sich vor allem um ein Aneurysma spurium, eine AV-Fistel, arterielle Dissektion oder direkte Gefäßverletzungen handelt. Bei undiagnostizierten Gefäßkomplikationen kann dies neben lokalen Komplikationen bei einer AV-Fistel mit bedeutsamem Shunt-Volumen bei herzinsuffizienten Patienten fatale Folgen haben.□ FallberichtWir berichten über eine mittels farbkodierter Duplexsonographie diagnostizierte kombinierte Gefäßkomplikation von Pseudoaneurysma und AV-Fistel, wobei ungewöhnlicherweise die AV-Fistel von dem Pseudoaneurysma ausging.□ SchlußfolgerungBei Verdacht auf eine Gefäßkomplikation nach Katheteruntersuchung sollte unverzüglich eine farbkodierte Duplexsonographie durchgeführt werden, die nach erfolgter Diagnosesicherung zu konservativen oder operativen Konsequenzen führen muß, um den Patienten durch verzögerte oder unzureichende Maßnahmen nicht zu gefährden.Summary□ BackgroundLocal vascular complications after transfemoral cardiac catheterization occur with an incidence of 5%. Most commonly these lesions are pseudoaneurysms, av-fistulas, arterial dissections or direct vascular injuries. Undiagnosed vascular lesions can lead to fatal consequences especially in patients with chronic heart failure by av-fistula with significant shunt volume.□ Case ReportWe report a vascular complication of combined pseudoaneurysm and av-fistula originated from the pseudoaneurysm. The lesion was diagnosed by color Doppler ultrasound.□ ConclusionThe suspicion of a vascular lesion after vascular catheterization should immediately lead to color Doppler ultrasound. Noninvasive duplexsonography will lead to early diagnosis of vascular complications and prompt further surgical or conservative intervention with reduction of long-term sequela and morbidity.BACKGROUND Local vascular complications after transfemoral cardiac catheterization occur with an incidence of 5%. Most commonly these lesions are pseudoaneurysms, av-fistulas, arterial dissections or direct vascular injuries. Undiagnosed vascular lesions can lead to fatal consequences especially in patients with chronic heart failure by av-fistula with significant shunt volume. CASE REPORT We report a vascular complication of combined pseudoaneurysm and av-fistula originated from the pseudoaneurysm. The lesion was diagnosed by color Doppler ultrasound. CONCLUSION The suspicion of a vascular lesion after vascular catheterization should immediately lead to color Doppler ultrasound. Noninvasive duplexsonography will lead to early diagnosis of vascular complications and prompt further surgical or conservative intervention with reduction of long-term sequela and morbidity.

Standardization of Carotid Ultrasound Response

Background and Purpose —Accurate carotid Doppler examination is an important issue in the light of large endarterectomy trials, but recommended cutoff values for detection of >70% stenosis vary widely. Standardization of diagnostic criteria should consider patient variation and instrument variability. Methods —We prospectively analyzed various Doppler parameters in 44 patients undergoing carotid angiography to evaluate whether normalization through individual reference measurements from the common carotid artery or the distal internal carotid artery could improve accuracy. For assessment of interindividual and interequipment variability, we performed repeated measurements of 40 carotid arteries in 21 patients. Two color-coded duplex ultrasound systems were compared for machine variability estimation: Hewlett Packard SONOS 2500 and ATL Ultramark 9 HDI. Results —Intrastenotic divided by distally recorded mean blood flow velocity (mean velocity ratio) showed the closest correlation with angiography: R 2=0.93. Mean velocity ratio >5 was 97% sensitive and 98% specific for detection of >70% carotid stenosis. Intrastenotic blood flow velocities were significantly different between the 2 duplex systems (0.22±0.16 versus 0.17±0.11 m/s; P <0.001), whereas mean velocity ratio values did not differ significantly. Interobserver variation expressed as 95% CI for predicted stenosis between 2 observers was 13.6% (peak systolic velocity) and 15.4% (mean velocity ratio). Conclusions —A mean velocity ratio using distal reference measurement in the internal carotid artery can normalize for interindividual and interequipment variability.