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Biomedical subjects

Antonio Colombo

Publications and source records attributed to Antonio Colombo.

At least 163 records · Page 9Linked to original sources
PubMed2003

Modified T-stenting technique with crushing for bifurcation lesions: immediate results and 30-day outcome.

We report a new stenting technique employed in 20 consecutive patients to treat true bifurcation lesions using the Cypher stent (Cordis, Warren, NJ). Both stents are advanced at the site of the bifurcation. The proximal marker of the side-branch stent must be situated in the main branch at a distance of 4-5 mm proximal to the carina of the bifurcation and the main branch stent must cover the bifurcation as well as the protruding segment of the side-branch stent. The side-branch stent is deployed first and balloon and wire are removed. The stent deployed in the main branch completely covers and crushes the protruding segment of the side branch stent against the vessel wall of the main branch. Following main- and side-branch predilatation, stents were successfully deployed in all lesions. Final kissing balloon inflation was performed in seven patients. Two patients had in-hospital myocardial infarction and one patient underwent in-hospital re-PTCA due to a dissection distal to a stent. No other major adverse cardiac events were observed in-hospital and during 1-month clinical follow-up. Treatment of bifurcation lesions using crushing stent technique is feasible with acceptable rate of procedural complications. Angiographic follow-up is necessary to prove the advantage of this specific technique to give complete coverage of the ostium of the side branch with a drug-eluting stent.

Angioplasty, Balloon, Coronary↗
PubMed2003

Initial experience with a new 8 French-compatible directional atherectomy catheter: immediate and mid-term results.

The purpose of this study was to evaluate the safety and efficacy of the new Fox Hollow atherectomy device (FHT) designed for more efficient and easier plaque removal. The FHT has short rigid section and low-profile cutter mounted on a monorail catheter. The FHT catheter was utilized in 77 patients with 98 lesions. Mean reference vessel diameter was 2.75 +/- 0.51 mm. Successful atherectomy with tissue retrieval was performed in 94 lesions (96%). Following atherectomy, mean diameter stenosis was reduced from 71.1% to 31.9% and further to 10.4% following adjunctive treatment. Angiographic complications were one coronary perforation and one adventitial staining, both successfully treated with prolong balloon inflation and stent implantation. Nine patients (11.7%) had in-hospital non-Q-wave myocardial infarction (MI). One patient died (1.3%) for noncardiac reasons and one had MI (1.3%) at 6-month follow-up. Target lesion revascularization was required in 13 (13.8%) lesions and target vessel revascularization in 15 (20.3%) patients. There was target vessel failure in 17 (23.0%) patients. Plaque debulking with the FHT catheter can be performed safely and effectively in relatively small vessels and complex lesions located in mid-distal artery segments with 6-month clinical outcome similar to prior atherectomy devices.

Aged↗
PubMed2003

Intravascular ultrasound based dose assessment in endovascular brachytherapy.

BACKGROUND: the role of endovascular brachytherapy in restenosis prevention is well documented. Dose is usually prescribed at a fixed distance from the source axis by angiographic quantification of vessel diameter. Recently, intravascular ultrasound (IVUS) was introduced in dose prescription, allowing a better evaluation of the vessel anatomy. This study retrospectively explores the difference between prescription following angiographic vessel sizing and delivered dose calculated with IVUS. METHODS AND RESULTS: Seventeen lesions were studied with IVUS, identifying on irradiated segment, three sections on which measuring minimal and maximal distance from the centre of IVUS catheter to the adventitia; using dedicated software, corresponding doses were calculated. The dose ranged widely, with maximal and minimal values of 71.6 and 4.9 Gy; furthermore, heterogeneity in dose among different sections was observed. In the central section, the maximal dose was 206% of the one prescribed with the QCA model at 2 mm from the source axis, while the minimal dose was 96%. In proximal and distal sections, respective values were 182, 45, 243, and 122%. CONCLUSIONS: Our analysis confirmed the dose inhomogeneity delivered with an angiographic fixed-dose prescription strategy. A dose variation was found along the irradiated segment due to the differences in vessel thickness. IVUS emerged as an important tool in endovascular brachytherapy, especially for irregular-shaped vessels.

Angioplasty, Balloon, Coronary↗
PubMed2003

Transplantation of autologous endothelial cells induces angiogenesis.

This study examined the feasibility and efficacy of autologous endothelial cell (EC) transplantation using a fibrin matrix in the ischemic myocardium of sheep. Four weeks after placing an ameroid constrictor in the circumflex artery of 12 adult sheep, four animals (EC group) were subjected to EC transplantation. In four others (saline [SAL] group) saline with added inactivated cells was injected and four animals served as controls. Eight weeks after treatment the animals were sacrificed to assess histology and ultrastructure. Eight weeks after injection, ventricular function was markedly improved in the EC transplant group, but had deteriorated in the SAL and control groups. Myocardial blood flow was also increased in the EC group. Histology and electron microscopy revealed extensive neovascularization after EC transplantation and improved myocardial appearance. Heterotopic transplantation of EC within a fibrin matrix enhances neovascularization, increases myocardial blood flow, and improves left ventricular function.

Animals↗
PubMed2003

Elective versus provisional intra-aortic balloon pumping in high-risk percutaneous transluminal coronary angioplasty.

BACKGROUND: Elective intra-aortic balloon pump (IABP) support may reduce acute complications occurring during percutaneous coronary interventions (PCI) in patients with severe depression of the left ventricular ejection fraction (EF < or = 30%). METHODS: Since February 1998, 133 consecutive patients with EF < or =30% underwent elective PCI in our institution; 61 had elective preprocedural IABP support (group A) and 72 patients had conventional PCI (group B). Jeopardy score was calculated in each patient from the coronary angiograms to quantify the myocardium at risk. RESULTS: EF was similar in the 2 groups. Jeopardy score was higher in group A (8.0 +/- 2.8 vs 6.7 +/- 2.4, P =.008). The other principal clinical and angiographic characteristics were similar in the 2 groups. Severe hypotension and/or shock occurred in 11 patients, all in group B (P =.001). All required urgent IABP support, and 3 eventually died. Intraprocedural major adverse cardiac and cerebral events (eg, myocardial infarction, severe hypotension and/or shock, urgent bypass surgery, stroke, and death) were higher in group B (17% vs 0%, P =.001). By stepwise logistic regression analysis, elective IABP support (odds ration [OR] 0.11 [95% CI 0.21-0.60], P =.011), jeopardy score (OR 5.37 [95% CI 1.10-8.70], P =.040), and female sex (OR 2.72 [95% CI 1.85-3.10], P =.015), were the correlates of intraprocedural events. CONCLUSIONS: This study supports the potential usefulness of elective versus provisional IABP to prevent intraprocedural major adverse cardiac and cerebral events in high-risk PCI.

Aged↗
PubMed2003

Regional thrombolytic therapy and stent implantation in an acutely occluded aortobifemoral bypass graft.

PURPOSE: To present a case highlighting the efficacy of local thrombolysis followed by stent implantation in acute occlusion of an aortobifemoral bypass graft. CASE REPORT: A 47-year-old man was referred to our catheterization laboratory for acute bilateral limb ischemia occurring 18 hours after an aortobifemoral bypass procedure. Angiography documented total occlusion due to massive thrombosis of the grafts. After 24 hours of local thrombolysis, repeat angiography showed complete lysis of the thrombus and an intimal flap in the abdominal aorta. A Palmaz stent was successfully implanted to cover the flap and restore adequate flow. At 1 year, the patient remains asymptomatic, and angiography showed patency of both the stent and the grafts. CONCLUSIONS: Based on this patient's response, local thrombolysis followed by stenting may be a safe and effective alternative to reoperation for the treatment of acute graft thrombosis caused by an intimal aortic flap. More experience with this approach is necessary to determine if this is an acceptable and effective mode of treatment.

Acute Disease↗
PubMed2003

A randomized comparison of direct stenting versus stenting with predilatation in native coronary artery disease: results from the multicentric Crosscut study.

Stenting without predilatation has become possible due to the availability of a new generation of flexible, low-profile, securely crimped, balloon-expandable stents. This study compared the feasibility, efficacy and cost-effectiveness of direct stenting (DS) to the standard predilatation technique (PS) using the premounted Crossflex LC stent (Cordis Corporation, Miami Lakes, Florida). The study is a randomized prospective multicenter evaluation including 271 patients (140 patients in the DS group and 131 patients in the PS group) with 1 or 2 de novo or restenotic lesions located in native coronary arteries. Procedural success was 98.9% and 98.7% in the DS and PS groups, respectively (p = NS); crossover to PS was required in 22/166 lesions (13.2%) enrolled in the DS group because of inability to cross the target lesion without predilatation. Nonsignificant reductions in procedural time (-10.5%), fluoroscopy time (-4.7%) and amount of contrast (-3.8%) were observed in the DS group in comparison to the PS group. The number of balloons used (-76.6%) and the global cost of the procedure (-18.8%) were significantly lower in the DS group (p < 0.01 for both comparisons). After 6 months, no differences were observed in the restenosis rate between the two groups (22.0% for DS group versus 18.1% for PS group; p = NS) and in the incidence of major adverse clinical events (5.0% for DS group versus 3.0% for PS group; p = NS). Direct stenting is safe and feasible for the treatment of lesions in native coronary arteries and obtains a significant reduction in procedural cost, mainly due to the lower number of balloons used. Clinical and angiographic results at 6 months are comparable to those obtained after a conventional predilatation-stenting strategy.

Catheterization↗
PubMed2003

Distal embolization during directional coronary atherectomy.

We report 2 cases of directional coronary atherectomy performed by using the Percu-Surge System to prevent distal embolization. A discrete amount of material was aspirated after the procedure. No clinical sequelae occurred in the immediate follow-up. These cases underline the problem of distal embolization during directional atherectomy, and the possibility to prevent it by using protection devices.

Atherectomy, Coronary↗
PubMed2003

Insulin-treated diabetes mellitus and predictors of mid-term clinical outcome after percutaneous coronary interventions with stent implantation.

BACKGROUND: Patients with type II, insulin-dependent diabetes mellitus have a high risk of death and repeat revascularization following successful percutaneous coronary interventions. The predictors of outcome in such patients after coronary stenting have not been clarified. METHODS: We studied 133 consecutive patients with type II, insulin-dependent diabetes mellitus who underwent coronary stenting from November 1992 to May 2001. The clinical outcome and predictors of major adverse cardiac events (MACE; that is death, myocardial infarction, target vessel revascularization) at follow-up were assessed. RESULTS: Out of 133 patients, 102 (76%) had multivessel (> or = 2 vessels) disease. Eight patients (6.0%) had in-hospital MACE. Clinical follow-up data at 19.5 months (range 6.1-100 months) were available for 121 (91%) patients. The MACE rate was 40.5%; 22 patients (18%) died, 17 (14%) of a cardiac death; 7 (5.8%) patients had a myocardial infarction, and target vessel revascularization was performed in 35 (28.9%) patients. At univariate analysis, hypertension (odds ratio-OR 5.5; confidence interval-CI 2.5-12.3; p < 0.001), hypercholesterolemia (OR 3.7; CI 1.7-8.2; p = 0.001), a prior percutaneous coronary intervention (OR 6.6; CI 2.9-15.4; p < 0.001), a prior myocardial infarction (OR 3.1; CI 1.5-6.7; p = 0.003) and the stent length (> or = 15 mm) (OR 2.7; CI 1.5-4.3; p = 0.008) were related to MACE. At multivariate analysis, hypertension (OR 4.1; CI 1.7-9.9; p = 0.002), a prior percutaneous coronary intervention (OR 4.8; CI 1.9-12; p = 0.001) and the stent length (OR 3.0; CI 1.3-7.4; p = 0.01) remained as independent predictors of MACE. CONCLUSIONS: Patients with insulin-dependent diabetes mellitus continue to face a high mortality and incidence of adverse events after stenting. The occurrence of events was related to a history including hypertension, percutaneous coronary interventions and to the stent length.

Aged↗