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Biomedical subjects

B Meier

Publications and source records attributed to B Meier.

At least 415 records · Page 23Linked to original sources
PubMed1987

Coronary wedge pressure in relation to spontaneously visible and recruitable collaterals.

Coronary angiography demonstrates only collateral arteries that are already in use (spontaneously visible collaterals). Percutaneous transluminal coronary angioplasty (PTCA) provides an opportunity to uncover collaterals ready to become functional in case of occlusion of the recipient artery (recruitable collaterals). The incidence of recruitable collaterals and their relation to the distal pressure in the occluded artery (coronary wedge pressure) during a 30 sec or longer balloon occlusion was assessed in 57 coronary arteries of 49 patients undergoing PTCA for a proximal coronary stenosis or occlusion. Collateral to 75% of the arteries were present. Spontaneously visible collaterals were four times as frequent as recruitable collaterals. Coronary wedge pressure was significantly higher in arteries with spontaneously visible and recruitable collaterals (41 +/- 12 and 36 +/- 12 mm Hg, respectively) than in arteries without collaterals (18 +/- 4 mm Hg). A coronary wedge pressure of 30 mm Hg or higher was found exclusively in the presence of collaterals. Electrocardiographic changes during balloon occlusion were found more frequently with arteries without collaterals than with arteries with spontaneously visible or recruitable collaterals. Chest pain was more frequent in patients without collaterals or with recruitable collaterals than in those with spontaneously visible collaterals. Major in-hospital events occurred in three patients with collaterals, with a salutary influence of the collaterals in two. The coronary wedge pressure allows prediction of recruitable collaterals. Their clinical impact remains to be investigated in long-term studies on large patient populations.

Angioplasty, Balloon↗
PubMed1987

[Chronic total coronary occlusion dis-obstruction by balloon angioplasty].

Ninety-three consecutive patients with chronic total coronary occlusion underwent an attempted mechanical des-obliteration by percutaneous coronary angioplasty with a balloon catheter. The global results were 55 p. 100 initial successes (residual stenosis less than 50 p. 100). The good prognostic factors were: 1) left coronary artery, especially left circumflex artery occlusion p less than 0.50, and 2) the proximity to the date of occlusion as assessed from the clinical history or by the occurrence of occlusion between the time of diagnostic coronary angiography and angioplasty. In cases of recent occlusion dating less than one month, the success rate was high: 69 p. 100. On the other hand, there were no successes in occlusions of over 6 months standing. The presence of myocardial infarction did not influence the results. There were few complications (7 p. 100) and these did not include any deaths or cases requiring emergency surgery. Exercise stress tests were carried out after the procedure and were negative in 28 out of 32 patients (88 p. 100). Forty-three patients successfully revascularised were followed up for 1 to 48 months (average 9 months) after angioplasty. Thirty-one patients were asymptomatic. Of the 12 symptomatic patients, 7 underwent exercise stress tests (6 positive) and all had control angiography which showed restenosis in 10 cases with 5 occlusions. Percutaneous coronary angioplasty of recent total coronary occlusions gives good initial results without major complications, and the medium term clinical results are satisfactory.

Adult↗
PubMed1987

[Angioplasty of internal mammary artery and saphenous vein bypasses and native coronary vessels in a patient with rapidly progressing disease].

Although coronary artery bypass is an effective treatment for patients with coronary artery disease, early graft failure is sometimes observed. We report here on a patient who had triple-vessel coronary bypass surgery, and 3 subsequent coronary angioplasty procedures of grafts and native vessels in the 13 following months, because of recurrence of angina. Each procedure was followed by disappearance of signs and symptoms of myocardial ischemia. This case illustrates the complementary approach of coronary artery bypass surgery and percutaneous angioplasty to myocardial revascularization in patients with rapidly progressive coronary disease.

Angina Pectoris↗
PubMed1987

Comparison of multivessel coronary angioplasty with surgical revascularization with both internal mammary arteries.

To evaluate medium-term clinical results of two major methods of myocardial revascularization, we compared 80 consecutive patients with multivessel percutaneous transluminal coronary angioplasty (PTCA) with 80 consecutive patients with coronary surgery using both internal mammary arteries in all and additional venous grafts in some. Patients in the surgical group had a higher extent of coronary artery disease. In patients with PTCA a mean of 2.2 vessels per patient were attempted, and in patients with surgery 2.7 distal anastomoses per patient were performed. Primary success for PTCA and surgery was 86% vs 94% and complications occurred in 7% vs 6%, respectively. Control angiograms, done in 86% of patients (59/69) after successful PTCA, showed a recurrence in 42% (25/59). Repeat PTCA was done in 15, elective surgery in seven, and a medical treatment was pursued in 3% patients with restenosis. Recurrence of symptoms after successful surgery was found in three patients (4%). They were treated with PTCA. Clinical follow-up was available for all patients, at a mean of 12 +/- 6 months after PTCA and 16 +/- 9 months after surgery. Mean improvement was 1.5 NYHA functional classes after successful PTCA and 2.1 after surgery; 60% (48/80) vs 89% (48/80), respectively, were in class I (p less than .0001). There were fewer PTCA patients than surgical patients without antianginal drugs at follow-up (19% [11/58] vs 37% [18/48]; p less than .05), and their double product during exercise testing was inferior (272 +/- 56 vs 295 +/- 47 mm Hg X beats/min/100; p less than .05). Medium-term clinical outcome appears better after successful surgery with both internal mammary arteries than after successful multivessel PTCA.

Adult↗
PubMed1987

Recurrence of stenosis after first and repeat coronary angioplasty. Clinical and angiographic follow-up.

The incidence of restenosis after initially successful first coronary angioplasty and the long-term effectiveness of repeat angioplasty for recurrence were examined on the basis of data on 282 consecutive patients with successful angioplasty. Primary success of first coronary angioplasty was obtained in 86% of patients and major complications (death, acute myocardial infarction and emergency coronary bypass surgery) occurred in 5% of patients. Control coronary angiography 10 +/- 6 months after successful angioplasty in 195 patients documented recurrence of stenosis in 33%. Repeat angioplasty was attempted in 52 patients with a primary success of 92%. One patient sustained an acute infarction as a complication of the procedure (2%). Control coronary angiography 7 +/- 4 months after a successful second procedure in 28 patients documented a second recurrence of stenosis in 39%. Recurrence rates after first and second coronary angioplasty were comparable (33 vs 39%, ns) but, for lesions of the left anterior descending coronary artery, recurrence was observed more frequently after second than after first angioplasty (47 vs 31%, p less than 0.05). Restenosis after second angioplasty, but not after first, was more frequent in women than in men. Patients with second recurrence were older than those with continuing angiographic success (59 +/- 8 vs 50 +/- 12 years, p less than 0.05). Recurrence was treated by a third coronary angioplasty in 5 patients, with success in all. Clinical follow-up 8 +/- 6 months after the last successful procedure was available for all 43 patients with repeat angioplasty who did not cross over to coronary surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Percutaneous transluminal coronary angioplasty in patients with silent myocardial ischemia during exercise testing.

Silent myocardial ischemia was present in 50 of 507 patients undergoing PTCA. Of these patients, five had type 1 (asymptomatic with no previous myocardial infarction), 27 had type 2 (asymptomatic after myocardial infarction) and 18 had type 3 silent myocardial ischemia (angina present in addition to silent episodes). Ischemia was documented in all patients in the exercise ECG, in 18 patients with thallium scintigraphy and in four with radionuclide ventriculography. The indication for PTCA was considered established in patients with type 1 silent ischemia based on ECG changes in the presence of high grade stenosis of the left anterior descending artery under the assumption of improved prognosis. The fact that patients with myocardial infarction have a poorer prognosis in the presence of ST-segment depression served as the basis for the indication for PTCA in type 2 patients. In type 3 patients, PTCA was carried out to ameliorate the symptomatic as well as asymptomatic episodes of ischemia. The follow-up period averaged 12 +/- 6 months. The primary rate of success was 92% with no differences between the groups. There were no complications in type 1 and type 2 patients; in two patients with type 3 silent ischemia, immediate bypass surgery was carried out due to acute occlusion of the dilated vessel. One patient in the latter group had myocardial infarction in the region perfused by the dilated vessel four months after the procedure. The angiographically-documented rate of restenosis was 33% in type 1 patients, 26% in type 2 and 40% in type 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1987

Technology of current dilatation systems and methodological procedures.

To fully exploit the advantages of modern dilatation systems, a state-of-the-art X-ray apparatus is of importance. It should be combined with a high resolution video chain with still-frame capabilities for guidance during the intervention. The trend in guiding catheters has moved to more flexible instruments (8 F) with preserved torque control and soft tips. This allows a more active manipulation of guiding catheters. Modern coronary guidewires leave little to be desired: their floppiness can be selected according to the problem to be solved. Long guidewires or extendible guidewires permit balloon exchanges without renegotiation of the stenosis. Very thin guidewires (0.010 in. or 0.25 mm) have been produced for low profile balloons. Special balloon catheters like the Tandem balloon, the Mainz continuous perfusion balloon, and the Doppler tip balloon may be useful in particular cases. Entirely different balloons systems like the Monorail system (only the balloon is riding on the guidewire) or the Omniflex system (the curvature of the balloon tip is shapeable from the outside), may become the standard equipment in some centers. Permanently implanted endoluminal stents may be a solution to the problem of acute occlusion and restenosis, if their promising initial results can be confirmed or even improved.

Cardiac Catheterization↗
PubMed1986

[Trefoil balloon, a new instrument for percutaneous valvuloplasty].

Complete obstruction of blood flow during balloon inflation is a major problem of percutaneous balloon valvuloplasty. To ensure continued transvalvular blood flow the authors have developed the "Trefoil balloon" consisting of three identical angioplasty balloons mounted on a single catheter. The Trefoil balloon was tested in the aorta and aortic valve in 4 dogs and produced a pressure gradient from 5 to 40 mm Hg where conventional balloons were completely occlusive. The Trefoil balloon was then used in 3 children with congenital valvular stenoses (2 pulmonary and 1 aortic stenosis). The immediate results of these valvuloplasties were satisfactory. Continued flow during balloon inflation was documented by right ventricular injection of contrast medium in the cases of pulmonary stenosis and by a systolic aortic pressure of 75 mm Hg during balloon inflation in the case of aortic stenosis. The Trefoil balloon is a promising new device for percutaneous valvuloplasty.

Angioplasty, Balloon↗
PubMed1986

Trefoil balloon for percutaneous valvuloplasty.

A new balloon (Trefoil balloon) was developed to avoid complete interruption of blood flow during percutaneous balloon valvuloplasty. It consists of three identical 2- to 4-cm-long angioplasty balloons mounted in a parallel fashion on a single catheter. Filled simultaneously, they assume the cross section of a rosette, allowing for continued blood flow. Trefoil balloons of various sizes were tested in five dogs (aorta and aortic valve). They created a gradient ranging from 5 to 40 mmHg where conventional, single balloons of comparable size were completely obstructive. In three consecutive patients with congenital pulmonary stenosis, Trefoil balloons were used successfully and without significant complications. Continued transvalvular blood flow during the actual dilatation process was documented in all cases. The Trefoil balloon is a promising new device for percutaneous valvuloplasty and, perhaps, coronary angioplasty.

Adolescent↗
PubMed1986

Clinical evaluation of soft-tipped catheters for coronary angiography.

New soft-tipped Judkins catheters for coronary angiography were compared with conventional femoral catheters for coronary angiography in a randomized, controlled fashion with cross-over exchange of catheters when problems occurred. The problems encountered with a first generation of soft-tipped catheters (n = 113) versus conventional catheters (n = 103) were as follows: difficult introduction 27% versus 1% (p less than 0.01), difficult placement 13% versus 8% (not significant), difficult aspiration 4% versus 0% (p less than 0.05), wedging 5% versus 0% (p less than 0.05), spasm 3% versus 0% (not significant), overselectivity 7% versus 2% (not significant), cross-over necessary and successful 18% versus 1% (p less than 0.01). Problems with a second generation of soft-tipped catheters (n = 200), modified according to the experience gathered from the first generation, versus conventional catheters (n = 194) were as follows: difficult placement 10% versus 7%, difficult aspiration 2% versus 0.5%, wedging 2% versus 1%, spasm 1% versus 0%, overselectivity 3% versus 2%, ventricular fibrillation 1.5% versus 0%, cross-over necessary and successful 3% versus 2%. None of the differences attained statistical significance. The performance of soft-tipped catheters for coronary angiography was inferior for the first generation but comparable for the second generation to that of conventional catheters. In terms of safety, soft-tipped catheters were not superior on the basis of our criteria.

Angiography↗
PubMed1986

Tandem balloon catheter for coronary angioplasty.

The Tandem balloon catheter is a triple lumen steerable catheter for coronary angioplasty with two separately inflatable balloons of different diameters. Indications and results of 26 consecutive patients treated with a Tandem balloon catheter are reviewed. Adequate distal pressure measurements were obtained in 71% of the cases. In ten patients, the Tandem balloon catheter was selected for two stenoses in different segments of the same coronary artery. Angioplasty was successful for all lesions in five and for at least the strategic lesions in five patients (in one only after changing to a single-balloon catheter). In the seven patients with stenoses in two different coronary arteries of various calibers, angioplasty was successful for both vessels in three and for one vessel in four patients. In the six patients with a very tight stenosis, where the Tandem balloon catheter was selected to predilate with the small balloon, the procedure was technically successful in all, but there was a myocardial infarction in one patient. In the three patients with a chronic total occlusion, where the stiffness of the Tandem balloon was the reason for selection, one recanalization was successful. The Tandem balloon catheter provides a handy tool for complex coronary angioplasty. It offers comparable ease in manipulation and pressure transmission and may save time, money, and radiation exposure by avoiding catheter exchanges.

Aged↗
PubMed1986

Physician as patient. The example of coronary angioplasty.

The outcome and behavior of 43 consecutive physicians undergoing percutaneous transluminal coronary angioplasty were compared to those of 43 control patients (non-physicians) matched for sex, arteries attempted, and time of intervention. As for baseline characteristics, the groups were similar but fewer physicians smoked or took beta-blockers and fewer control patients took calcium-blockers. The immediate outcome of both groups showed no significant differences. The in-hospital management was not different either except that physicians complained more often about pain than control patients. Complaints about care or complaints of the nursing personnel about patients were found with equal frequency in both groups. The saying that "physicians are the worst patients" could not be substantiated in the example of coronary angioplasty, yet neither were their care and outcome superior to those of control patients.

Adult↗