Atherectomy for ostial LAD stenosis: "a cut above".
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Atherectomy, Coronary↗
Biomedical subjects
A Colombo
Publications and source records attributed to A Colombo.
Modified "T" stenting: a technique for kissing stents in bifurcational coronary lesion.
The kissing stenting using a new technique in two patients is reported. A stent was positioned at the ostium of the side branch. Another stent was advanced into the main vessel until the center of the stent was positioned near the origin of the side branch. The stent at the ostium of the side branch was deployed and the balloon and the guidewire were removed from the side branch. Thereafter, the stent in the main vessel was deployed. The follow-up angiogram of those patients showed no restenosis in both the vessels.
Aged↗
Focal stent collapse in a patient with systemic sclerosis.
We report a patient with systemic sclerosis having implantation of a 35 mm beStent with immediate success but developing angina at follow-up. A focal stent collapse with focal hyperplasia in and outside the stent was documented by ultrasound after 2 mos. A 14mm Palmaz-Schatz stent was successfully deployed into the collapsed beStent, with good 6-mo angiographic result. The stent collapse was probably due to unequal distribution of radial forces and possibly reactive hyperplasia in this unique patient with systemic sclerosis.
Aged↗
Low restenosis rate in lesions of the left anterior descending coronary artery with stenting following directional coronary atherectomy.
The present study evaluated acute and late results with stenting following directional coronary atherectomy (DCA) for the lesions in the left anterior descending coronary artery (LAD). Between April 1995 and January 1997, 200 LAD lesions with > or =3 mm reference vessel diameter were treated with coronary stents. The lesions were divided as to whether or not DCA was performed before stenting; 1) stenting alone (n = 163) and 2) debulking and stenting (n = 37). There were no significant differences in the incidences of complications except for non-Q-wave myocardial infarction that was more frequent in patients with debulking and stenting than in those with stenting alone (13.5% vs. 2.4%, P < 0.05). A greater acute lumen gain (2.85 +/- 0.66 vs. 2.25+/-0.60 mm, P < 0.01) and minimal lumen diameter (3.64+/-0.56 vs. 3.15+/-0.41 mm, P < 0.01) after stenting were observed in patients with debulking and stenting than in those with stenting alone. At follow-up patients with debulking and stenting continued to have a greater minimal lumen diameter (2.88+/-0.72 vs. 2.15+/-0.85 mm, P < 0.01) and had a lower restenosis rate (6.3% vs. 23.1%, P < 0.05) than those with stenting alone. Stenting following DCA appears to be advantageous in the LAD lesions with > or =3 mm reference vessel diameter.
Aged↗
Clinical feasibility of 0.018-inch intravascular ultrasound imaging device.
OBJECTIVES: Intravascular ultrasound imaging (IVUS) is limited by the size of the imaging catheter. To facilitate imaging before and during interventions, a 30-MHz ultrasonic imaging device was developed that is the same dimension as a 0.018-inch guide wire. The purpose of this study was to evaluate the clinical feasibility of this device. METHODS AND RESULTS: The imaging core was tested in 8 patients with the use of a monorail guiding sheath that was advanced through a 7F catheter. In addition, after coronary interventions, the standard guide wire was removed, the imaging core was placed inside a compatible balloon, and imaging was performed. In 4 patients, imaging was also performed with a standard 3.2F IVUS catheter. The lumen-plaque interface and the media-plaque interface were clearly visualized in all patients. There was no detectable loss in image quality between the new imaging device and the larger IVUS catheter, and measurements of lumen cross-sectional area were not statistically different. CONCLUSIONS: Improvements in manufacturing technology have permitted the development of a mechanically rotating ultrasound imaging core 0.018 inches in diameter. It is compatible with current balloon catheters without degradation of image quality.
Cardiac Catheterization↗
Mechanical recanalization of total coronary occlusions with the use of a new guide wire.
The mechanical approach in the recanalization of total coronary occlusions consisted of the use of a new 0.014-inch standard coronary guide wire with jointless spring coil design that improves steering characteristics and tip stiffness. In addition, a 0.014-inch soft tip wire with hydrophilic coating and low-profile 1.5 mm over-the-wire balloons were used. The first wire was used selectively in 86 patients to treat 95 total occlusions, of which 51 (54%) were older than 3 months. Unfavorable angiographic characteristics were present in 79 (83%) of 95 lesions. Overall crossing success was 71% (67 of 95 lesions). Complications were one coronary perforation with cardiac tamponade necessitating emergency bypass surgery. In conclusion, the mechanical approach with the use of the standard coronary guide wire with jointless spring coil design provides a high success rate in the recanalization of unfavorable total occlusions.
Angioplasty, Balloon, Coronary↗
Molecular approaches to evaluate pollutants.
Many organisms are in use to test pollutants and their extensive variability clearly emerges from reviews since researchers in the world are involved in continuous effort to set up new assays and to improve those already in use. In the present paper we focus the attention on the mixed function oxidase system and the DNA adduct formation which are two biomarkers widely used and extensively studied in mammals and fish by different Authors. We compare their results with the ones we obtained in amphibians, which result to be a good model. Moreover we present some significative results obtained by the use of cultured cell lines to test the herbicide MCPA. The results obtained demonstrate that the amphibian Xenopus is a suitable indicator for induction of cytochrome P-450 by B[a]P as well as for production of DNA adducts. Cultured cells evidenced that cytoskeletal array and thiol proteins are molecular targets of the herbicide used, demonstrating that risk assessment can be properly analysed in in vitro systems.
2-Methyl-4-chlorophenoxyacetic Acid↗
Identification of a multixenobiotic resistance mechanism in Xenopus laevis embryos.
In the '90's a membrane-associated transport protein, discovered in aquatic organisms, was considered to be expressed in response to environmental xenobiotics. Like the multidrug resistance protein found in mammalian tumor cell lines, this protein confers resistance in organisms in polluted areas by binding xenobiotics and transporting them out of the cells in an energy-dependent manner. This study investigates the expression and the activity of a P-glycoprotein (Pgp) involved in a multixenobiotic resistance mechanism (MXRM) during the early developmental stages and in tissues of adult Xenopus laevis.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Bioindicators for toxicity assessment of effluents from a wastewater treatment plant.
The discharge of effluents and toxic compounds into aquatic systems represents a growing environmental problem involving an impact on water ecology and potential effect on human health. Most municipal wastewaters are complex mixtures; their complexity led as to carry out a hazard assessment using chemical analyses and biological tests. This study investigates biochemical alteratiobns in two sentinel organisms, the Anodonta cygnea mussel and the Xenopus laevis frog exposed for different lengths of time to various concentration of wastewater of the S. Antonino Ticino treatment plant. The results point out the long-life of toxic compounds.
Animals↗
Coronary artery stenting in the elderly: short-term outcome and long-term angiographic and clinical follow-up.
OBJECTIVES: This study sought to compare the short- and long-term outcomes of elderly patients undergoing coronary artery stenting with those of younger patients and to determine the long-term clinical outcome and survival of elderly patients post stent implantation. BACKGROUND: Elderly patients undergoing coronary revascularization are considered a high-risk group. Few data exist that relate the results of stenting in treating coronary artery disease in the elderly population. METHODS: All elderly patients >75 years of age who underwent coronary artery stenting between March 1993 and July 1997 (n=137) at our center were compared to the patients <75 who underwent coronary artery stenting during the same time period (n=2,551). Long-term clinical follow-up and survival were determined for the elderly group. RESULTS: Elderly patients presented with lower ejection fractions (54% vs. 58%, p=0.0001), more unstable angina (47% vs. 28%, p=0.0001), and more multivessel disease (78% vs. 62%, p= 0.0001) than younger patients. These older patients had higher rates of procedure related complications including procedural myocardial infarction (MI) (2.9% vs. 1.7%, p=0.2), emergency CABG (3.7% vs. 1.4%, p=0.04), and death (2.2% vs. 0.12%, p=0.0001). Angiographic follow-up, obtained in both groups, demonstrated significantly higher restenosis rates in the elderly versus younger patients (47% vs. 28%, p=0.0007). Longer term clinical follow-up, which was obtained only in the elderly group, showed that at a mean follow-up period of 12 months post coronary stenting, elderly survival free from death, MI, revascularization and angina was 54% and that their overall survival was 91%. Subanalysis of the elderly patients who died showed much higher incidence of combined unstable angina (80%), prior MI (60%), lower ejection fraction (46%), multivessel disease (100%) and complex lesions (100%) than the overall group. CONCLUSIONS: Elderly patients who undergo coronary artery stenting have significantly higher rates of procedural complications and worse six month outcomes than younger patients, especially those who present with combined unstable angina, history of MI, EF < 50%, multivessel disease and complex lesions. Overall survival in the elderly population at 12 months postcoronary artery stenting was 91% and event-free survival was 54%.
Aged↗
Fournier's gangrene: a clinical presentation of necrotizing fasciitis after bone marrow transplantation.
Three patients with ANLL developed Fournier's gangrene as an early complication after allo-BMT (two cases) and auto-BMT (one case); two patients were in first CR, the third had resistant disease. Patients developed fever, perineal pain, swelling and blistering of the genital area. Pseudomonas aeruginosa was isolated from the lesions and patients received systemic antibiotic therapy, surgical debridement and medication with potassium permanganate solution. Two patients made a complete recovery although one died of sepsis. The third had progressive involvement of the abdominal wall and later died of leukemia. Early diagnosis of this disorder and prompt initiation of appropriate therapy can prevent progression of this acute necrotizing infection.
Abdominal Muscles↗
Clinical application and image interpretation in intracoronary ultrasound. Study Group on Intracoronary Imaging of the Working Group of Coronary Circulation and of the Subgroup on Intravascular Ultrasound of the Working Group of Echocardiography of the European Society of Cardiology.
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Angioplasty, Balloon, Coronary↗
Intravascular ultrasound-guided optimized stent deployment. Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)
OBJECTIVES: A study was set up to validate the safety and feasibility of intravascular ultrasound-guided stenting without subsequent anticoagulation, and its impact on the 6 months restenosis rate. METHODS: The study was designed to be multicentred, prospective, and observational. RESULTS: One hundred and sixty-one patients with stable angina and a de novo coronary artery lesion were enrolled. In four patients, the implantation of a Palmaz-Schatz (with spiral bridge) stent had failed. One of these four patients died 3 days following bypass surgery. In two other patients, intravascular ultrasound assessment was not performed. One hundred and twenty-five of the remaining 155 patients (81%) were treated with aspirin (100 mg x day(-1)), because all three criteria for optimized stent expansion were met. Twenty-two of the remaining 38 patients (25%), in whom at least one criterion was not met were treated with aspirin and acenocoumarol (3 months, INR 2.5-3.5), while 16 patients only received aspirin. Stent thrombosis was documented in two patients (1.3%) for which repeat angioplasty was performed. During the hospital stay, there were no deaths or Q-wave myocardial infarctions. Five patients (3.2%) sustained a non-Q-wave myocardial infarction. During the follow-up period (198+/-38 days, complete for all patients, except one), one patient (0.6%) sustained a Q-wave myocardial infarction, one (0.6%) underwent bypass surgery, and repeat angioplasty was performed in nine patients (5.7%). In two of the nine patients, repeat angioplasty involved another lesion. Therefore, the target lesion revascularization rate during follow-up was 4.5% (seven patients). At quantitative coronary angiography, the minimal lumen diameter (mean+/-SD) increased from 1.12+/-0.34 mm before to 2.89+/-0.35 mm after stenting. Repeat angiography at 6 months was performed in 144 patients (92%). The minimal lumen diameter at follow-up was 2.12+/-0.67 mm. Restenosis (diameter stenosis of 50% or more) was documented in 12 patients or 8.3%. When the two patients with documented stent thrombosis are included, the restenosis rate amounts to 97%. CONCLUSIONS: These data confirm that, in selected patients, stents can safely be implanted without the use of systemic anticoagulation, provided optimal stent expansion is achieved. The exact role of intravascular ultrasound in the achievement of these results needs to be established by appropriately designed studies. In the meantime, intravascular ultrasound coupled with the Palmaz-Schatz stent incorporating a spiral bridge, may have contributed considerably to the immediate angiographic outcome, which in turn may explain the favourable clinical and angiographic outcome at 6 months.
Aged↗
Assessment of the coupling between RTapex and RR interval as an index of temporal dispersion of ventricular repolarization.
To evaluate the dynamic characteristics of the relationship between the RT and RR intervals we analyzed the RR/RTapex variability interaction with a dynamic parametric model whose parameters can be directly estimated from the beat-to-beat series RR and RTapex intervals. The model is designed to separate the fraction of RTapex variability driven by RR changes from that independent of RR variations and to quantify the gain and phase of the relationship between RR and RTapex intervals. The percentage of RTapex variability driven by RR variability was significantly greater in young normal subjects in comparison with postmyocardial infarction patients as well as with age-matched control subjects. This new approach based on the quantification of the RTapex variability dependent and independent of beat-to-beat RR interval changes could be used to quantify the degree of uncoupling between the two signals thus providing a new and noninvasive index of temporal dispersion of ventricular repolarization.
Adult↗
Procedural and follow up results with a new balloon expandable stent in unselected lesions.
OBJECTIVE: To assess the clinical and angiographic results of the first clinical application of a new balloon expandable stent, the NIR stent, characterised by high longitudinal flexibility and low profile before expansion, and by high radial support and minimal recoil and shortening after expansion. DESIGN: Single centre survey of unselected lesions in consecutive patients. SETTING: Tertiary referral centre. PATIENTS AND LESIONS: 93 stents of various length (9, 16, and 32 mm) were implanted in 64 lesions in 41 patients. Twenty lesions (31%) were longer than 15 mm, and 17 lesions (27%) were located in vessels with a diameter smaller than 2.5 mm. Extreme tortuosity of the proximal vessel was present in 15 lesions (23%). All patients were treated with aspirin and ticlopidine. All lesions were evaluated before and after treatment by quantitative angiography, and in 47 lesions (75%) the stent expansion was also controlled by intracoronary ultrasound. Clinical follow up was available in all patients and angiographic follow up was performed in 53 lesions (84%), at a mean (SD) interval of 5.4 (1.7) months. RESULTS: Deployment of the stent failed in two lesions (3%). Minimum lumen diameter increased from 1.01 (0.54) mm to 2.94 (0.49) mm, and diameter stenosis decreased from 66(15)% to 7(11)%. There was one in-hospital non-Q wave myocardial infarction, one sudden death after 40 days, and 17 target lesion revascularisations (27%). Angiographic restenosis (> or = 50% diameter stenosis) was documented in 19 lesions (36% of all lesions with angiographic follow up), with an average residual diameter stenosis of 43(21)% and minimum lumen diameter of 1.63 (0.74) mm. Restenosis was more common in vessels with a reference diameter < 2.5 mm (45%) and for lesions longer than 15 mm (46%). CONCLUSIONS: The NIR stent could be used successfully in most lesions, achieving optimal angiographic results with very few in-hospital or subacute cardiac events. The angiographic restenosis rate and need for target lesion revascularisation remained high in this unfavourable lesion subset, especially in small vessels and long lesions.
Catheterization↗
Quantitative description of the morphology of the human palate by a mathematical equation.
OBJECTIVE: To derive a three-dimensional mathematical description of normal human hard tissue palatal size and shape. METHODS: The maxillary dental casts of 30 adolescents free from respiratory problems, who had a complete (28 teeth) permanent sound dentition with normal occlusion, were studied. The x, y, z coordinates of several standardized palatal and dental landmarks were obtained with a computerized three-dimensional digitizer. Palatal landmarks were used to derive a mathematical equation of palatal shape in the frontal and sagittal planes. Palatal width, length, frontal and sagittal heights, and sagittal slope, as well as dental arch transverse and anteroposterior dimensions, were computed. RESULTS: Neither the size nor the shape of the palate was significantly influenced by gender. Only the intercanine distance was larger (p < .025) in males than in females. CONCLUSIONS: Data collected in the present investigation could represent a first database for the quantitative description of normal human palatal morphology in subjects with a complete permanent dentition.
Adolescent↗
Plaque removal prior to stent implantation in native coronary arteries: why? When? And how?
Coronary stenting has significantly reduced restenosis in focal de novo coronary lesions, but its impact in complex lesions has been less pronounced. Recent data suggest a possible role for pre-intervention plaque burden in exacerbating neo-intimal hyperplasia after stent implantation. These observations formed the basis for the hypothesis that plaque removal prior to stent implantation, using directional atherectomy in non-calcified lesions and rotational atherectomy in calcified lesions, may reduce restenosis. The currently available non-randomized experience that used this approach has shown its feasibility and favourable long-term outcome when applied in selected patients. However, the incidence of non-Q-wave myocardial infarction is increased with both rotational and directional atherectomy compared to PTCA or stent alone. The utilization of potent antiplatelet agents and/or the development of new atherectomy devices that produce lower embolization rate may decrease the incidence of these ischaemic complications. In addition, considering the increased procedural time and cost, this approach will have to be applied in selected patient subsets where debulking or stenting as a stand-alone strategy is associated with a high restenosis rate. Randomized clinical trials testing the usefulness of this approach, with both rotational and directional atherectomy, are currently in progress.
Angioplasty, Balloon, Coronary↗
Bifurcational stenting.
Treatment of bifurcation lesions is a complex issue, and there is no single panacea to the variety of lesions that form this cohort. The contribution of side-branch compromise to the adverse clinical events occurring after stent implantation need not be stressed and requires an aggressive approach including balloon dilatation before and after stent deployment. Various new techniques of kissing stent placement, such as the 'T', 'V', 'Y', and the culottes technique, have been proposed in recent years to treat different anatomical situations. The angle formed by the side-branches, the severity of involvement of the ostia and the vessel size are the main factors which influence selection of the strategy. Newer generations of stents, such as the bifurcate stents, tailor-made for bifurcation lesions, are evolving, and are expected to make a positive impact on the procedural outcomes and long-term results after bifurcation stenting. The development of new strategies and stent designs has greatly improved safety and immediate outcome of bifurcational stenting, but the procedural success still needs to be matched by an equal improvement in long-term patency.
Angioplasty, Balloon, Coronary↗