[The measurement by high resolution ultrasound of the intima-media thickness at the carotis comunis artery: early marker of atherosclerosis]

Since 1986, published from the P. Pignoli's group in Italy, the measurement by B-Mode Ultrasound of the carotid Intima Media Thickness is considered a very important tool for the assessment of cardiovascular risk in epidemiological trials but also for pharmacological studies. After more than 20 years the improvement of the technology in Ultrasound systems and the computer semiautomatic assisted analysis has permitted the standardisation of the method as suggested in the Mannheim and Brussels 2004-2006 Consensus. In vivo carotid IMT analysis is probably the first step for the evaluation of beginning and early atherosclerosis even before detectable lesions defined as plaque are observed. In particular situations by patients with high cardiovascular risk, the measurement of the IMT can be helpful for the decision to treat them more aggressively even in primary prevention.

[Anatomy by ultrasound of the veins in the leg: essentials]

Studying the anatomy of lower extremity veins is a tedious and complex task. Although huge efforts have been undertaken to create harmonization, any global description of the venous network is encumbered by the large number of superficial and deep veins, anastomoses and collaterals, and not least by a vastly broad nomenclature. Innumerable anatomic variants contribute to creating a complicated picture. What is needed is a description that correspondingly reflects the reality. Yet, does our description reproduce the actual anatomic and pathologic circumstances? As a rule, a phlebography is performed to localize an acute or chronic venous condition. The examiner must have learn about the "healthy" to What the stethoscope is to a cardiologist, the Doppler sonography transducer was to the phlebologist, an indispensable tool. Nowadays, duplex sonography has to be called the gold standard in that it supplies the most comprehensive information for diagnosing functional disorders of the venous system, thereby enabling a clear therapeutic strategy to be delineated. Most qualitatively average or high-grade ultrasound machines are equipped with duplex sonography, which today's specialists can employ to highly efficiently render a differential diagnosis of deep vein thrombosis. Given the ethic and forensic background and the potentially lethal outcome of a misdiagnosis, the use of this diagnostic tool must be exclusively reserved for physicians with a particularly high level of skill and training. The specialist societies for ultrasonography, angiology and phlebology have published strict guidelines for teaching Doppler sonography in Switzerland.

Effects of probucol versus aspirin and versus brachytherapy on restenosis after femoropopliteal angioplasty: the PAB randomized multicenter trial

PURPOSE

To evaluate the effect of probucol and/or of endovascular brachytherapy (EVBT) on restenosis after percutaneous transluminal angioplasty (PTA) of femoropopliteal arteries.

METHODS

A total of 335 patients (206 men; mean age 72+/-9 years) with intermittent claudication were randomized according to a 2x2 factorial design to 1 of the 4 groups: probucol, placebo, EVBT, and EVBT+probucol. Probucol (1 g/d) or placebo were given in double-blinded fashion 1 month before and for 6 months after PTA. Gamma irradiation (192Iridium, 14 Gy, 5-mm reference depth) was randomly applied in an unblinded manner from a noncentered endoluminal catheter. All patients received aspirin (100 mg/d). Primary endpoint was restenosis (>50% diameter reduction) detected by duplex ultrasound 6 months after PTA. Secondary endpoints included clinical and hemodynamic assessment.

RESULTS

Restenosis in patients undergoing EVBT was 17% (23/133) versus 35% (50/142) in patients without EVBT (p<0.001); in patients treated with probucol versus placebo, the rates were 23% (31/135) and 30% (43/140, p<0.001). Three quarters (77%, 102/133) of patients were free of claudication after EVBT therapy versus 61% (87/142) without EVBT (p<0.05). Need for target vessel revascularization was 6% (8/133) with EVBT versus 14% (20/142) without EVBT (p<0.01). Late thrombotic occlusions occurred in 4% (6/133), exclusively in patients treated with EVBT after stent implantation.

CONCLUSIONS

Endovascular brachytherapy significantly reduces restenosis, improves symptoms, and reduces reinterventions after PTA of femoropopliteal arteries. Probucol reduces restenosis but has no additive effect when combined with brachytherapy.

Telementoring During Endovascular Treatment of Abdominal Aortic Aneurysms:A Prospective Study

PURPOSE

To explore the use of telementoring for distant teaching and training in endovascular aortic aneurysm repair (EVAR).

METHODS

According to a prospectively designed study protocol, 48 patients underwent EVAR: the first 12 patients (group A) were treated at a secondary care center by an experienced interventionist, who was training the local team; a further 12 patients (group B) were operated by the local team at their secondary center with telementoring by the experienced operator from an adjacent suite; and the last 24 patients (group C) were operated by the local team with remote telementoring support from the experienced interventionist at a tertiary care center. Telementoring was performed using 3 video sources; images were transmitted using 4 ISDN lines. EVAR was performed using intravascular ultrasound and simultaneous fluoroscopy to obtain road mapping of the abdominal aorta and its branches, as well as for identifying the origins of the renal arteries, assessing the aortic neck, and monitoring the attachment of the stent-graft proximally and distally.

RESULTS

Average duration of telementoring was 2.1 hours during the first 12 patients (group B) and 1.2 hours for the remaining 24 patients (group C). There was no difference in procedural duration (127+/-59 minutes in group A, 120+/-4 minutes in group B, and 119+/-39 minutes in group C; p=0.94) or the mean time spent in the ICU (26+/-15 hours in group A, 22+/-2 hours in group B, and 22+/-11 hours for group C; p=0.95). The length of hospital stay (11+/-4 days in group A, 9+/-4 days in group B, and 7+/-1 days in group C; p=0.002) was significantly different only for group C versus A (p=0.002). Only 1 (8.3%) patient (in group A: EVAR performed by the experienced operator) required conversion to open surgery because of iliac artery rupture. This was the only conversion (and the only death) in the entire study group (1/12 in group A versus 0/36 in groups B + C, p=0.31).

CONCLUSIONS

Telementoring for EVAR is feasible and shows promising results. It may serve as a model for development of similar projects for teaching other invasive procedures in cardiovascular medicine.

Thrombus aspiration as a bailout procedure during percutaneous renal angioplasty

PURPOSE

To present a case in which thrombus aspiration, urokinase, and abciximab were used to recanalize a sudden acute thrombotic occlusion of the right renal artery during percutaneous renal angioplasty.

CASE REPORT

A 72-year-old man with severe arterial hypertension, impaired renal function, and peripheral artery disease was referred for interventional renal revascularization of a proximal stenosis of the right renal artery. Predilation was unsuccessful, and stent placement was followed by immediate occlusion of the distal renal artery, probably due to dislocation of a mural thrombus. Since intra-arterial administration of urokinase (300,000 IU) was ineffective, thrombus aspiration was performed using the 7-F guiding catheter. After successful removal of the thrombus, abciximab was given intravenously. Control angiograms showed recanalization of the stented segment and patency of the distal renal arteries, an outcome confirmed 8 months later by duplex ultrasound.

CONCLUSIONS

As demonstrated in our case, thromboembolic complications can be rapidly and successfully treated on the table by combined measures, such as catheter thrombus extraction and pharmacological strategies.

Preoperative embolization of collateral side branches: a valid means to reduce type II endoleaks after endovascular AAA repair

PURPOSE

To report the results of preprocedural embolization of collateral branches arising from abdominal aortic aneurysms (AAA) scheduled for endovascular repair.

METHODS

Twenty-three consecutive AAA patients (all men; mean age 73 years, range 56-82) had coil embolization of patent lumbar and inferior mesenteric arteries (IMA) in a staged procedure prior to endovascular repair. Embolization with microcoils was attempted in 37 of the 52 identified lumbar arteries and 14 of 15 inferior mesenteric arteries. Follow-up included biplanar abdominal radiography, spiral computed tomography, and duplex ultrasonography at 1, 30, 90, and 180 days after the stent-graft procedure and at 6-month intervals thereafter.

RESULTS

Successful embolization was obtained in 24 (65%) of lumbar arteries, while all 14 (100%) IMAs were occluded with coils. No complication was associated with embolotherapy. Over a mean 17-month follow-up of 22 patients (1 intraoperative death), there was only 1 (4.5%) type II endoleak from a patent lumbar artery, with no sac expansion after 2 years. There were 4 (18%) type I and 1 (4.5%) type III endoleaks.

CONCLUSIONS

The embolization of side branches arising from an infrarenal aortic aneurysm before endovascular repair is feasible, with a high success rate; this maneuver may play a relevant role in reducing the rate of type II endoleak, improving long-term outcome.

Late acute thrombotic occlusion after endovascular brachytherapy and stenting of femoropopliteal arteries

OBJECTIVES

The aim of this article is to underline the importance of this complication after endovascular brachytherapy (EVBT) and intravascular stenting of the femoropopliteal arteries occurring in a running randomized trial.

BACKGROUND

Endovascular brachytherapy has been proposed as a promising treatment modality to reduce restenosis after angioplasty. However, the phenomenon of late acute thrombotic occlusion (LATO) in patients receiving EVBT after stenting is of major concern.

METHODS

In an ongoing prospective multicenter trial, patients were randomized to undergo EVBT (iridium 192; 14 Gy at a depth of the radius of the vessel +2 mm) after percutaneous recanalization of femoropopliteal obstructions. Of the 204 patients who completed the six months follow-up, 94 were randomized to EVBT.

RESULTS

Late acute thrombotic occlusion occurred exclusively in 6 of 22 patients (27%) receiving EVBT after intravascular stenting and always in concomitance with reduction of antithrombotic drug prevention (clopidogrel). Conversely, none of the 13 patients with stents and without EVBT (0%; p < 0.05) and none of the 72 patients (0%; p < 0.01) undergoing EVBT after simple balloon angioplasty presented LATO.

CONCLUSIONS

Late thrombotic occlusion occurs not only in patients undergoing EVBT after percutaneous coronary recanalization but also after stenting of the femoropopliteal arteries and may compromise the benefits of endovascular radiation. The fact that all our cases with LATO occurred concomitantly with stopping clopidogrel may indicate a possible rebound mechanism. An intensive and prolonged antithrombotic prevention is probably indicated in these patients.

Is there a place for duplex screening of brachial artery in haemodialysis patients with vascular access?

BACKGROUND

Vascular access (VA) stenosis with subsequent thrombosis remains one of the major causes of morbidity and hospitalization in haemodialysis patients. The present cross-sectional study was planned in order to analyze the usefulness of brachial artery duplex ultrasound for detection and prediction of vascular access stenoses.

METHODS

Color duplex ultrasound (Apogée Cx200, sectorial probe 7.5 MHz) was used to obtain the anatomical pattern of the VA and flow velocity waveforms of the brachial artery in 77 non-selected VA (47 Ciminio-Brescia fistulae and 30 PTFE grafts). In each VA, the resistance index (RI), the mean blood flow rate (Q) and the blood flow ratio index (QI) (QI = VA flow rate/contralateral flow rate) were calculated at the level of the brachial artery. The sensitivity and specificity of these brachial Doppler parameters were calculated for the detection of VA stenosis. In normal VA, positive (PPV) and negative predictive (NPV) values were calculated for the development of clinical stenotic complications 3 months post ultrasound examination.

RESULTS

Thirteen of the 77 VA (17%) were identified as stenosed by duplex ultrasound and confirmed by fistulography and/or during surgical exploration. The best screening tests for VA stenosis detection were a QI threshold < 4.0 with a sensitivity and specificity of 69 and 69% and an RI > 0.55 with a sensitivity and specificity of 62 and 66%, respectively. In the VA considered as normal by ultrasound, the prediction of subsequent stenosis within three months post-ultrasound examination gave a PPV of only 18% and 19% for RI and QI, respectively. NPV for RI and QI were 90% and 88%.

CONCLUSIONS

While Doppler ultrasound is a useful non-invasive test for the detection of prevalent VA stenosis, our results do not confirm that abnormal brachial Doppler flow parameters can predict short term development of VA stenosis.

[Reference values of intima-medial thickness of carotid and femoral arteries in subjects aged 20 to 60 years and without cardiovascular risk factors]

Many studies have shown a close correlation between intima-medial thickness of the carotid artery measured by high resolution ultrasonography and the presence of coronary artery disease or atherogenic risk factors. However, reference values for the value of intima-medial thickness (IMT) in healthy subjects have not yet been established. The aim of this study was, therefore, to determine the reference values of carotid (C-IMT) and femoral intima-medial thickness (F-IMT) with respect to age and gender in healthy subjects (53 women and 45 men) aged 20 to 60, with no family or personal history of cardiovascular disease or atherogenic risk factors, underwent high resolution colour echo-Doppler examination. The mean C-IMT was 556 +/- 57 microns in women and 573 +/- 70 microns in men (NS), and the femoral equivalent was 543 +/- 63 microns in women and 562 +/- 74 microns in men (NS). Between the ages of 20 and 60, the C-IMT increased by 1.8 microns per year (p < 0.03) in women and 3.4 microns (p < 0.001) in men, the variations being respectively 1.2 microns (NS) and 3.1 microns (p < 0.002) in the femoral artery. Multiple regression analysis including gender and individual values of age, body mass index and lipid profile confirmed that only age was significantly correlated to the increase in thickness. The authors conclude that the reference values of IMT do not differ with gender or site of analysis, but there is a slight influence with respect to age.

In-vitro motility of normal and pathological smooth muscle of colon

This study is based on the in-vitro analysis of the normal and pathological colon smooth muscle contraction. Two different methods, supported by computer analysis, are presented. This approach will probably help the physician and the surgeon to better understand the physiopathology of some characteristical diseases, such as Hirschsprung's disease.