The Tracker catheter: a new vascular access system

Venture wire control catheter

We wished to test the safety and efficacy of a novel wire control catheter for use during percutaneous coronary intervention. The ability to vary the angulation of the tip of an intravascular guidewire would often be desirable. Previous attempts to produce deflectable-tip guidewire systems have met with limited success. The Venture wire control catheter (Velocimed, Minneapolis, MN) was used to facilitate percutaneous coronary intervention in 20 patients. There were no device-related complications. Percutaneous coronary intervention was successful in all patients. Our initial experience with the Venture wire control catheter has been favorable.

Utility of Pilot wire in angioplasty of tortuous and highly angulated coronary arteries

We present a case of severe proximal circumflex artery tortuosity with two 90 degrees bends and then a tight stenosis in the mid part of first obtuse marginal branch. Conventional method used to cross the lesion by wire failed. However, a commercially available new wire with ability to change the degree of tip angulation (Pilot wire, USCI Bard) was then used successfully to cross the stenosis. In addition, the wire straightened the tortuosities and provided good trackability to the balloon. Thus, this new wire is a valuable addition to the angioplasty armamentarium.

Combined mechanical and thrombolytic treatment for totally occluded bypass grafts

Totally occluded venous grafts are usually less amenable to mechanical reperfusion alone (for example percutaneous transluminal coronary angioplasty, PTCA) because of the large mass of thrombotic material within the graft. A combined approach using mechanical and thrombolytic treatment might therefore be more successful. Twenty one patients (20 males, one female) with a mean age of 64.5 (SD 5.6) years underwent angiography because of crescendo or unstable angina (n = 19) or myocardial infarction (n = 2) at a mean of 21.7 (18.6) days after onset of symptoms (range 1-60). All patients had had coronary artery bypass grafting (CABG) at a mean of 8.02 (4.02) years (range 0.3-13 years) before the current admission. At catheterisation, totally occluded venous bypass grafts to the left anterior descending coronary artery or diagonal (n = 10), marginal (n = 6), or right coronary artery (n = 5) were found. A combination of PTCA and thrombolytic treatment (in eight patients extended thrombolysis for 24 hours) was successful in reopening the venous graft in 16/21 patients (76.2%). Immediate complications included femoral haematoma (4), distal embolisation (3), and infection in one patient. Out of 13 patients catheterised within three months, two had reoccluded, seven had restenosis, while four had patent grafts. Recurrent PTCA (at least once more) was done in eight patients. At long term follow up of a mean of 26.7 (21.6) months (range 4-75 months), four patients were asymptomatic, eight still suffered from mild stable angina, while three had recurrent hospital admissions and needed a second coronary artery bypass. A combination of thrombolytic treatment and PTCA is a feasible and practised approach to recanalise recently occluded venous bypass grafts.

Response of conductance and resistance coronary vessels to scalar concentrations of acetylcholine: assessment with quantitative angiography and intracoronary Doppler echography in 29 patients with coronary artery disease

Abnormal vasoreactivity of the large conductance arteries has been observed in the presence of impaired endothelial function. More recently, experimental and clinical reports have shown that in early coronary atherosclerosis the impairment of the endothelium-mediated vasodilatation also involves the resistance arteries. The aim of this study is the correlation of endothelium-dependent vasodilatation of conductance and resistance vessels in coronary arteries without significant stenoses. In 29 patients (aged 57 +/- 9 years, 24 men and 5 women) undergoing coronary angioplasty, a Doppler guide wire and a perfusion catheter were introduced into the proximal segment of an artery with less than 30% diameter stenosis. Selective infusions of papaverine (bolus of 7 mg), acetylcholine (continuous infusion of 0.036, 0.36, and 3.6 micrograms/ml at a flow rate of 2 ml/min), and isosorbide dinitrate (bolus of 3 mg) were sequentially performed. Heart rate, aortic blood pressure, and blood flow velocity were continuously measured. Mean cross-sectional areas of a proximal and a distal arterial segment were measured in baseline conditions, at the end of each infusion of acetylcholine, and at the peak effect of isosorbide dinitrate with quantitative angiography (CAAS System; Pie Medical Data, Maastricht, The Netherlands). Coronary blood flow was calculated from the time-averaged flow velocity and the cross-sectional area at the site of the Doppler sample volume. Coronary flow resistance was calculated as mean aortic pressure divided by coronary flow. All of the concentrations of acetylcholine induced a significant vasoconstriction of the studied artery. At the maximal concentration of acetylcholine all but three patients (90%) showed a reduction of cross-sectional area (-24% +/- 20% and -22% +/- 20% for the proximal and distal segments, respectively, p < 0.00001). Flow velocity showed a significant increase only with the two highest concentrations of acetylcholine. The maximal concentration induced a 105% +/- 138% increase from the baseline flow velocity (p < 0.001). The coronary flow changes after acetylcholine showed a large interpatient variability, with a mean increase from baseline after the highest dose of +43% +/- 85% (range, -60% +/- 239%), with the presence of a flow reduction in 10 patients (35%). No clinical or angiographic variables showed a significant correlation with the cross-sectional area, flow velocity, and flow changes after infusion of acetylcholine.(ABSTRACT TRUNCATED AT 400 WORDS)