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Biomedical subjects

E Camenzind

Publications and source records attributed to E Camenzind.

32 records · Page 2Linked to original sources
PubMed1995

Intracoronary heparin delivery in humans. Acute feasibility and long-term results.

BACKGROUND: Inefficacy of systemic drug administration for restenosis prevention may partially relate to insufficient local drug concentration. This study aimed to evaluate the acute feasibility and long-term outcome of using an infusion-perfusion coil balloon, Dispatch. METHODS AND RESULTS: In 22 patients after balloon angioplasty, the coil balloon was studied for (1) feasibility of local heparin delivery, (2) symptoms and signs of ischemia during prolonged deployment compared with angioplasty balloon occlusion, (3) coronary pressure and flow distal to the inflated device, and (4) long-term clinical and angiographic results. During prolonged intracoronary deployment of the coil balloon (29 +/- 8 minutes), 5 of 22 patients developed mild chest pain versus 20 of 22 during angioplasty (275 +/- 283 seconds). Neither hemodynamic nor vectorcardiographic signs of ischemia were detected, in contrast to angioplasty balloon occlusion. Baseline flow across the coil balloon was 44 +/- 31 mL/min, increasing by a factor of 1.8 +/- 0.7 during pharmacologically induced hyperemia. A mean volume of 14.2 +/- 6.1 mL containing 1416 +/- 608 IU of heparin was infused locally at a pressure of 122 +/- 54 mm Hg. At 7 +/- 1-month follow-up, 1 asymptomatic patient had died, and of the remaining 21, 17 (81%) were asymptomatic. Angiographic follow-up was obtained in 15 of 21 patients (71%), including all 4 symptomatic patients. Mean minimal luminal diameter after the procedure was 2.16 +/- 0.49 mm and at follow-up, 1.89 +/- 0.45 mm, which corresponds to a restenosis rate (diameter stenosis > or = 50%) of 7% (1/15). CONCLUSIONS: Intracoronary use of the coil balloon after balloon angioplasty proved to be feasible and subjectively as well as objectively well tolerated during prolonged deployment by virtue of its perfusion properties. High volumes of heparin solution can be infused locally at very low pressure. No unfavorable clinical or angiographic long-term effects were observed.

Adult↗
PubMed1995

Quantitative assessment with intracoronary ultrasound of the mechanisms of restenosis after percutaneous transluminal coronary angioplasty and directional coronary atherectomy.

The mechanisms of immediate and late changes after percutaneous transluminal coronary angioplasty (PTCA) and directional coronary atherectomy (DCA) were assessed by serial ultrasound imaging in 18 patients treated with PTCA and 16 treated with DCA before, immediately after, and 6 months after coronary interventions. A reduction in plaque area was the main operative mechanism of DCA, explaining 66% of lumen enlargement. In the PTCA group, the increase in lumen area was the result of a more balanced combination of plaque reduction (52% of lumen increase) and increase in total lumen area (48%); p < 0.05 versus DCA. In the PTCA group, this last mechanism was prevalent (p < 0.05) in the lesions showing wall fracture or dissection after treatment and in the lesions with a mixed or calcific composition. In the PTCA group, concentric lesions showed a greater plaque compression than eccentric lesions (p < 0.02). Plaque increase was responsible for 92% and 32% of the late lumen loss after DCA and after PTCA, respectively (p < 0.05). In PTCA patients, a chronic reduction in total vessel area was the main operative mechanism of lumen reduction (67%) and was prevalent in lesions with a mixed or calcific composition. (p < 0.05).

Angioplasty, Balloon, Coronary↗
PubMed1995

Randomized evaluation of six French voda-type guiding catheters for left coronary artery balloon angioplasty.

In order to evaluate 6 French (6F) Voda-type guiding catheters for left coronary artery balloon angioplasty, we randomized the choice of the guiding catheter in 100 consecutive patients between a Voda (group 1, n = 50) and a Judkins or Amplatz curve (group 2) guiding catheter. Angioplasty success rate (98% for both), need for guiding catheter crossover exchange (2 in group 1 vs. 1 in group 2), fluoroscopy time, and volume of injected contrast were similar in both groups, but the operator's appreciation of good back-up support was better with the Voda-type guiding catheter (90% vs. 74%, P < 0.05). No complications attributed to the guiding catheter were noted in either group. Efficiency of the Voda-type guiding catheter appeared similar for both left anterior descending (n = 35, success rate 100%) and circumflex (n = 18, success rate 94%) coronary artery angioplasty. Voda-type guiding catheters are an efficient and safe approach to routine left coronary angioplasty. They appear to be as effective as a choice between a Judkins or an Amplatz configuration and could be of particular use when a double angioplasty of the left anterior descending and circumflex arteries is attempted during the same procedure.

Angioplasty, Balloon, Coronary↗
PubMed1994

Coronary angioplasty for isolated non-dominant left circumflex coronary artery disease.

The study describes the clinical findings and results of coronary balloon angioplasty in 134 patients with non-dominant left circumflex coronary artery disease. The immediate angiographic success rate was 97% versus 95% for left anterior descending (P = NS), and 90% for right coronary lesions (P < 0.002). There was no hospital mortality in the circumflex group versus 1.2% in the left anterior descending (P < 0.01), and 0.4% in the right coronary artery group (P = NS). Major non-fatal cardiac complications were significantly lower in the non-dominant left circumflex coronary artery patients (no new Q-wave versus 3% in the left anterior descending, P < 0.0002, and 3% in the right coronary artery group, P < 0.01; no urgent coronary artery bypass grafting versus 2% in the left anterior descending, P < 0.001, and 1% in the right coronary artery group, P = NS). The freedom from chest pain was 63% in 112 patients (84%) with follow-up data available at 24 +/- 18 months, and mean angina class diminished to 0.7 +/- 1.3 (P < 0.001). Consumption of antianginal and other cardiac drugs was diminished during follow-up, and the number of patients on no such drugs increased from 5 to 32% (P < 0.001). Restenosis was found in 19 of 32 patients with repeat coronary angiography (59%). Repeat angioplasty was required in 22 patients during follow-up and in 4 of them (18%) it was done for new lesions. Angioplasty for isolated non-dominant left circumflex coronary artery disease yields excellent immediate and long-term results.

Angioplasty, Balloon, Coronary↗
PubMed1994

Evaluation of the systematic use of a new type of diagnostic/interventional 6F catheters for coronary angiography and angioplasty.

Coronary angioplasty performed immediately after coronary angiography has raised interest to develop diagnostic catheters potentially usable for interventions (i.e. Diaventional catheters). To evaluate the performance and cost-effectiveness of such material, we performed a prospective study in 100 consecutive patients with a > 50% pre-angiographic likelihood of coronary angioplasty in 85 of them. Angioplasty was actually performed in 61 patients. Of the 56 (92%) immediate angioplasty procedures, 33 (59%) were performed successfully with the Diaventional catheter chosen initially. In 23 cases, another guiding catheter was used for technical failure (2 cases) or because of operator's choice (21 cases). Angiographic success of angioplasty procedures was 97% with Diaventional and 91% with "standard" guiding catheters. Based on current market prices, the costs of the systematic use of such diagnostic/interventional catheters were 11% less than the projected costs of the standard strategy. Thus, this new type of catheter is both safe and cost-effective for the majority of coronary angioplasty procedures "at first sight." It could become a logical first choice for diagnostic coronary angiography, when the likelihood of immediate subsequent angioplasty is high and at relatively low risk.

Adult↗
PubMed1994

Improving results of bailout coronary stenting after failed balloon angioplasty.

Stent implantation can be a valuable alternative to emergent bypass surgery to treat established or threatening abrupt closure following coronary balloon angioplasty. To evaluate several sequentially introduced changes in our practice of bail-out stenting, we compared the first (group I) and second half (group II) of our single center experience (n = 88). Use of bailout stenting increased over time (2% of all angioplasty procedures in group I vs. 6% in group II, P < 0.001), more often to prevent rather than to reverse abrupt closure. Technical success of stent implantation was unchanged (95% vs. 93%), and there was a decreasing trend for stent thrombosis (14% vs. 5%), in-hospital death (5% vs. 2%), Q-wave myocardial infarction (9% vs. 7%), and requirement for surgery (9% vs. 7%). The incidence of non-Q-wave myocardial infarction (29% vs. 7% P < 0.01), bleeding complications (27% vs. 7% P < 0.01), and hospital stay duration (11 +/- 11 vs. 8 +/- 5 days P < 0.05) decreased. Our data suggest that coronary stent implantation is currently an effective stand-alone bailout procedure for a large majority of failed angioplasty procedures.

Aged↗
PubMed1994

Collagen application versus manual compression: a prospective randomized trial for arterial puncture site closure after coronary angioplasty.

OBJECTIVES: This study evaluated the safety and efficacy of a newly developed puncture-sealing device consisting of subcutaneous bovine collagen application designed to facilitate local hemostasis after coronary angioplasty. BACKGROUND: The most common local hemostatic procedure after coronary angioplasty consists of heparin discontinuation and delayed sheath removal followed by mechanical compression at the puncture site. METHODS: Between December 1991 and February 1993, 124 patients undergoing coronary angioplasty with either a 6F guiding catheter followed by a heparin infusion for > 12 h or a 7F or 8F guiding catheter with optional heparin infusion were prospectively randomized to either delayed sheath removal followed by manual compression (n = 62) or sheath removal immediately after angioplasty combined with bovine collagen application for puncture site closure (n = 62). Half of the collagen plugs were delivered using measured and half using estimated skin-artery distance. Clinical and duplex sonographic evaluations of the puncture site were performed 24 h later. RESULTS: No significant difference in the incidence of local hematomas was observed. Major complications were false aneurysm, venous thrombosis and arterial occlusion. The incidence of false aneurysm was the same in both groups (4 [7%] of 62). Venous thrombosis (2%) and arterial occlusion (2%) were each recorded in one patient, both in the collagen application group. CONCLUSIONS: Sheath removal and collagen application with this new vascular hemostasis device used directly after coronary angioplasty are not superior to delayed sheath removal after heparin discontinuation followed by mechanical compression. Arterial collagen sealing with this device in its current form is associated with a small but worrisome risk of arterial occlusion.

Aged↗
PubMed1994

In-hospital monitoring after coronary angioplasty.

At the University Hospital of Geneva there are three postcoronary angioplasty monitoring levels: (A) intensive care unit; (B) optional ECG monitoring (cardiology unit); and (C) no monitoring (other unit). To assess the adequacy of patient monitoring after coronary angioplasty, we studied the clinical outcome of 200 consecutive patients undergoing coronary angioplasty at different monitoring levels. Thirty-nine patients (20%) were in level A. Their outcome was 1 death, 1 emergency bypass operation, and 7 acute myocardial infarcts. Ninety-six patients (48%) were in level B: no major complication, no transfer of monitoring level, and mean hospital stay 2.7 +/- 1.3 days. Sixty-five patients (32%) were in level C: 1 death, 2 elective bypass operations, 6 transfers to level A, and mean hospital stay 5.9 +/- 4.6 days. Electrocardiogram monitoring of 135 patients yielded 23 significant findings (17%), 22 of which occurred in patients with complicated or failed procedure. In the 122 patients with successful coronary angioplasty without angiographic visible local complications and without clinical symptoms at the end of the procedure, no significant arrhythmia or acute myocardial infarction was documented. For this type of patient, ECG monitoring is not a prerequisite after coronary angioplasty. Surveying all patients after coronary angioplasty in the coronary care unit would not significantly reduce complications. Aftercare in a cardiology unit results in a shorter hospital stay.

Adult↗
PubMed1994

[Immediate results of coronary endoprosthesis in threatening or occlusive dissections complicating angioplasty; the Geneva experience].

Between April 1988 and September 1993, 123 patients (average age 60.4 +/- 8.9 years) underwent coronary stenting for threatening or occlusive dissection complicating angioplasty. The anterograde coronary flow was disturbed in 51% of cases (TIMI-0-2). The artery concerned was the left anterior descending in 59% of cases, the right coronary in 28% of cases, the circumflex in 12% and a coronary bypass graft in 1% of cases. Technically, the stenting was successful in 118 cases (98%) and, in 21 cases, complete stenting of the dissection required the insertion of several stents. The minimal coronary diameter after expansion of the stent was 3.1 +/- 0.6 mm. During hospital follow-up, 3 deaths (3%) and 7 Q-wave infarcts were observed. Twenty-eight patients (23%) developed a haemorrhagic complication, including 2 retroperitoneal and 2 intracerebral bleeds. Eight patients (6%) underwent coronary bypass grafting, as an emergency in 4 cases and semi-electively in another 4 cases. One hundred and five patients (89%) survived the intra-hospital period without major complications (death, Q-wave infarction, emergency coronary bypass surgery or severe haemorrhage). Coronary stenting for threatening or occlusive dissection complicating angioplasty seems to be a reasonable solution and a usually definitive one. The frequency of haemorrhagic complications underlines the need for strict clinical and biological surveillance.

Aged↗
PubMed1993

[Coronary angioplasty in octogenarians].

Coronary balloon angioplasty was performed on 33 lesions during 28 procedures in 23 octogenarians (median age 83, range 80 to 87 years) between January 1989 and December 1991. 96% of the patients had grade III-IV angina pectoris. The median left ventricular ejection fraction was 64% (range: 38-85%). Single vessel coronary artery disease was present in 43% and multivessel coronary artery disease in 57%. Angioplasty was performed on 1 vessel in 85% of the procedures and on 2 vessels in 15%. Primary angiographic success was 97% for 33 attempted lesions with one failure to recanalize an old occlusion. One patient underwent emergency intracoronary stent implantation after failed angioplasty. None underwent emergency coronary bypass surgery. One patient (4%) had a myocardial infarction and 2 patients (7%) died during hospitalization, the first because of abrupt vessel closure during angioplasty, the second due to acute retroperitoneal bleeding on the 8th day post-angioplasty while fully anticoagulated for an intracoronary stent. Follow-up (median 17, range 8 to 39 months) was obtained for all patients. Out of the 21 patients with primary angioplastic success, 3 (14%) had died (1 cardiac and 2 non-cardiac). At 1 year actuarial survival was 86%, and survival free from myocardial infarction or coronary bypass surgery was 81%. Further angioplasty for either restenosis or another lesion was performed in 5 patients (24%). These results confirm that coronary angioplasty is an effective means of controlling anginal symptoms in a selected group of severely symptomatic octogenarians. However, when complications do occur they are linked to a significant mortality rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Limits of thallium-201 exercise scintigraphy to detect coronary disease in patients with complete and permanent bundle branch block: a review of 134 cases.

We reviewed the records of 68 patients with right bundle branch block (RBBB) and 66 patients with left bundle branch block (LBBB), who had undergone thallium-201 exercise scintigraphy and coronary arteriography, to determine the sensitivity, specificity, and positive and negative predictive values of thallium-201 imaging for the detection of coronary artery disease in the presence of intraventricular conduction abnormalities. In patients with RBBB the sensitivity, specificity, and positive and negative predictive values were, respectively, 83%, 89%, 79%, and 92% for the anteroseptal region and 83%, 84%, 83%, and 84% for the inferoposterior region. In patients with LBBB these values were, respectively, 94%, 33%, 36%, and 93% for the anteroseptal region and 77%, 90%, 81%, and 88% for the inferoposterior region. In this second group defects limited to the septal region were a good predictor of false positive scintigrams (9/10 cases), but if apical defects used as the sole criterion for detecting lesions in the left anterior descending artery improved the specificity to 85%, the sensitivity was greatly reduced (35%). We conclude that exercise scintigraphy is a reliable method for detection of coronary lesions in patients with RBBB and in patients with LBBB and inferoposterior perfusion defects, but it is unable to discriminate between normal subjects and patients with coronary disease in the presence of LBBB and anteroseptal perfusion defects. In addition, limited septal defects are highly suggestive of false positive scintigrams in this latter group of patients.

Adult↗
PubMed1991

Effect of the renin response during renin inhibition: oral Ro 42-5892 in normal humans.

The effect of the new renin inhibitor Ro 42-5892 was evaluated in healthy volunteers after both intravenous and oral administration. In a preliminary study, 14 subjects received a 10-min infusion of Ro 42-5892 at doses ranging from 0.001 to 1 mg/kg. Plasma renin activity (PRA) and angiotensin (Ang) II levels were maximally suppressed in a dose-dependent manner at the end of the infusion. Plasma active renin concentration increased up to threefold. In a second study, 24 volunteers received placebo or 100, 600, or 1,200 mg of Ro 42-5892 p.o. in a single-blind, randomized fashion. Within 30 min after drug intake, PRA and plasma Ang I and Ang II levels fell to their nadir. Both Ang I and Ang II were measured specifically after extraction on phenylsilylsilica and separation by isocratic HPLC. The degree as well as the duration of inhibition were dose related. The decrease in plasma Ang lasted maximally for 2 h. Active renin increased dose dependently and remained elevated for more than 8 h after the 1,200 mg dose. A theoretical generation rate of Ang I was calculated for individual plasma samples assuming Michaelis-Menten kinetics for competitive inhibition and steady-state conditions. This calculated Ang I generation rate, based on plasma active renin concentrations and drug levels, closely correlated with actually measured Ang I and Ang II levels (r = 0.90, n = 88) over the whole 8 h time period. Thus, a sustained renin inhibition by Ro 42-5892, as indicated by increased plasma active renin levels, induces a much shorter fall in plasma Ang I and II apparently because of a rise in renin secretion.

Administration, Oral↗
PubMed1988

Ischemic stroke as the presenting manifestation of localized systemic cancer.

A cerebral infarct due to a thrombosis of the left pericallosal artery was the first manifestation of an ovarian adenocarcinoma in a 42-year-old woman. A paraneoplastic origin was suggested by the observation that this patient had chronic intravenous coagulation and subsequently developed migratory thrombophlebitis (Trousseau's syndrome) despite high dose vitamin K antagonists therapy. This was supported by the fact that all manifestations of the hypercoagulable state disappeared following surgical cure of the cancer. Because cerebral infarction can be the first manifestation of a potentially curable cancer, patients with a cerebral infarct of an unknown etiology should be investigated for a malignant process, if there is laboratory or clinical evidence od disseminated intravascular coagulation.

Adenocarcinoma↗