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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 109 records · Page 6Linked to original sources
PubMed2000

Multicenter registry to evaluate the efficacy of the NIROYAL stent in de novo or restenotic coronary stenosis.

The purpose of this registry was to document the safety and efficacy of elective deployment of the NIROYAL stent (Boston Scientific SCIMED, Maple Grove, Minnesota) in coronary arteries. This was a prospective, multi-center international registry. NIROYAL stents (9, 16, 25 and 32 mm-long) were manually crimped onto coronary balloons and deployed in de novo or restenotic lesions in 165 male and female patients with angina pectoris and a reference vessel diameter of 2.0-4.5 mm. Stent deployment was successful in 98.8% of the lesions. Mean percent diameter stenosis decreased from 83.5+/-10.8% to 2.7+/- 6.2% after intervention. The interventional procedure of the treatment site was successful in 97.6% of patients. At six-month clinical follow-up, 88.5% had event-free survival [i.e., did not experience a major adverse cardiac event (MACE)] and 95.2% had no anginal symptoms. Furthermore, 87.3% of the patients were free of target vessel failure (defined as a composite of acute procedural failure, target vessel revascularization, myocardial infarction or death at six months). Only three MACE were observed within the first 30 days after stent implantation. A low left ventricular ejection fraction and the percentage stenosis pre-procedure were identified as statistically significant (p<0.05) predictive factors for MACE. The incidences of MACE and target vessel failure after six months follow-up were lower than that seen in other studies, and target lesion revascularization rates were low.

Adolescent↗
PubMed2000

Multivessel coronary stenting: predictors of early and late outcome.

BACKGROUND: At present, only few data are available on the early and late outcome following multivessel coronary stenting. Of note, in these studies, the left anterior descending (LAD) artery was treated in less than 40% of cases. These patients may not fully represent the population commonly referred for surgical revascularization. METHODS: In-hospital and long-term (18 +/- 4 months) events were evaluated in 272 consecutive patients who had multivessel stent implantation including the LAD artery in each case. All clinical, angiographic, and procedural variables were analyzed to identify the predictors of acute and long-term major adverse coronary events. RESULTS: Eighteen patients (6.6%) had in-hospital major adverse coronary events (death 0.7%, coronary artery bypass grafting 0.4%, and myocardial infarction 6.3%). Acute and subacute stent thrombosis rates were 1.5 and 1.1%, respectively. At 18 +/- 4 months, event-free survival was 71%. Target lesion revascularization was performed in 54 (20%) patients (42 coronary angioplasty and 12 coronary artery bypass grafting). The jeopardy score was the predictor of in-hospital major adverse coronary events (p = 0.016, odds ratio 1.34, 95% confidence interval 1.05-1.69), and diabetes mellitus was the predictor of long-term major adverse coronary events (p = 0.027, odds ratio 2.80, 95 % confidence interval 1.12-6.96). CONCLUSIONS: Multivessel coronary stent implantation with treatment of the LAD artery in all instances is a safe procedure with low acute and long-term major adverse coronary events. The risk-benefit ratio must be assessed carefully for each patient, particularly taking into account the jeopardy score and the presence of diabetes mellitus.

Aged↗
PubMed2000

Predictors of long-term clinical outcome in patients undergoing multiple vessel stenting for coronary artery disease.

BACKGROUND: Coronary artery stenting reduces the restenosis rate compared to coronary angioplasty alone. With the increased number of procedures completed with stent placement there has been a parallel increase in the number of procedures performed in patients with multivessel disease and therefore a rise in the number of patients receiving multiple stents. The clinical outcome and the predictors of the outcome of patients receiving multiple stents are not known. METHODS: To evaluate the clinical outcome of patients with multivessel coronary artery disease undergoing multiple stenting we studied 133 consecutive patients who had received > 1 stent in at least two vessels. A total of 375 coronary stents (2.8 stent per patient) were implanted in elective procedure situations. Clinical follow-up was complete in 100%. RESULTS: During follow-up 2 patients (1.5%) died (1 cardiac death), 4 patients (3%) had acute myocardial infarction, 96 patients (72.1%) remained angina-free, and 31 patients (23.3 %) had recurrence of angina. Repeat revascularization procedure was performed in 45 patients (33.8%); 43 patients (32.3%) underwent coronary angioplasty; 2 patients (1.5%) underwent coronary artery bypass grafting. The female gender and the presence of diabetes were significant (p < 0.05) predictors for coronary angioplasty or coronary artery bypass grafting procedures during follow-up. Recurrence of angina was also significantly (p < 0.05) associated with unstable angina at the time of the first procedure as well as diabetes and the female gender. Diabetes, the female gender and unstable angina were highly predictive factors of major adverse cardiac events during follow-up. CONCLUSIONS: Multiple vessel stenting in patients with multivessel coronary artery disease is associated with an acceptable immediate and long-term clinical outcome and could be considered as an alternative therapeutic option in these patients. Predictors of an adverse long-term outcome are the female gender and the presence of diabetes mellitus.

Angioplasty, Balloon, Coronary↗
PubMed2000

Effectiveness and complications of vascular access closure devices after interventional procedures.

BACKGROUND: Vascular closure devices are designed to obtain a fast hemostasis of the vascular access site after diagnostic and interventional procedures. This result should be obtained with a low incidence of complications. METHODS: A retrospective, non-randomized study was performed to evaluate the success rate and vascular complications associated with the use of two different vascular sealing devices [Angio-Seal (Daig Corporation, Minnetonka, Minnesota) and Prostar (Perclose, Inc., Redwood City, California)] after interventional procedures. RESULTS: Eight-hundred and twenty-seven devices were used (245 Angio-Seal and 582 Prostar). Angio-Seal success rate was 92% with a 2.5% rate of vascular complications; Prostar success rate was 89% with a 3.4% rate of vascular complications. Multivariate logistic regression analysis identified advanced age (p < 0.05) and lower weight (p < 0.05) as independent predictors of vascular complications associated with Angio-Seal use, while diabetes (p < 0.05) was found to be a predictor of vascular complications in the Prostar group. Abciximab use and larger sheath size were not associated with an increased probability of vascular complications. CONCLUSION: Angio-Seal and Prostar obtain a fast vascular access hemostasis after interventional procedures, with a low incidence of major vascular complications.

Angioplasty, Balloon, Coronary↗
PubMed2000

European high-activity (32)P radioactive stent experience.

Brachytherapy by implantation of a radioactive stent is an alternative approach to catheter-based systems to reduce restenosis. The pilot clinical trials using 32P radioactive b-emitting stents at low-to-intermediate activity (0.5Eth 3.0 mCi) showed that restenosis at 6 months was not different from that of currently available non-radioactive stents. The evaluation of the efficacy in reducing restenosis of radioactive stents with higher activities (3Eth 24 mCi) started in Europe (Milan, Rotterdam and Vienna) between 1998 and 1999. In the Milan and Rotterdam experience, 32P radioactive stents with an activity of 3Eth 12 mCi demonstrated a reduction of intra-stent restenosis to < 4%. However, a high-edge restenosis > 30% was observed in the first 1Eth 3 mm outside the stent margins. This edge effect might be due to a low dose of radiation at the stent margins combined with systematic balloon injury in the reference segments. The hypothesis that a further increase in stent activity (12Eth 21 mCi) associated with a reduced balloon injury outside the stent could solve the problem of edge restenosis was not confirmed by the Milan experience; edge restenosis still occurred in 26% of the lesions treated by a single 32P radioactive stent, even if a nonaggressive stent implantation strategy was used. Two approaches under investigation to solve the problem of edge restenosis are: 1) lengthening the stent with a non-radioactive stent (cold-ends stent) to prevent negative remodeling; and 2) extending the area of irradiation beyond the balloon-injured area by an increased activity at the stent ends (hot-ends stent).

Blood Vessel Prosthesis Implantation↗
PubMed2000

Contemporary percutaneous treatment of saphenous vein graft stenosis: immediate and late outcomes.

PURPOSE: The aim of this study was to evaluate the immediate and long-term outcomes following percutaneous treatment of an unselected series of saphenous vein graft (SVG) lesions. METHODS AND RESULTS: Consecutive interventions on 129 saphenous vein graft lesions in 101 patients were reviewed. Stents were implanted in 114 lesions (88%), which included the use of polytetrafluoroethylene-covered stents in 22 lesions (17%) and abciximab in 20 patients (20%). Angiographic success was achieved in 125 lesions (97%). In-hospital major adverse cardiac events (MACE) occurred in 11 patients (11%), with myocardial infarction being the most frequent event. Treatment of degenerated SVG lesions and SVG lesions with larger reference diameters correlated with the incidence of in-hospital MACE [odds ratio (OR) = 7.69 and 2.65, respectively; 95% confidence interval (CI) = 1.80Eth 32.8 and 0.99Eth 7.10, respectively)]. Clinical follow-up was achieved in all patients at 25 +/- 21 months. Successful revascularization to all three distributions of the major coronary arteries negatively correlated [relative risk (RR) = 0.43; 95% CI = 0.20Eth 0.92)], while treatment of a degenerated SVG positively correlated (RR = 1.92; 95% CI = 1.05Eth 3.51) with the occurrence of follow-up MACE. A final effective blood supply to the anterior wall and a higher left ventricular ejection fraction was found to negatively correlate with the occurrence of follow-up death (RR = 0. 20 and 0.61, respectively; 95% CI = 0.06Eth 0.60 and 0.41Eth 0.90, respectively). CONCLUSION: Treatment of SVG lesions continues to be associated with a high incidence of myocardial infarction, particularly in cases of degenerated SVG lesions. An effective blood supply to the anterior wall and a higher left ventricular ejection fraction were protective for the occurrence of death during the follow-up period.

Aged↗
PubMed2000

The Efficacy of Directional Atherectomy Prior to Stent Implantation.

Coronary stents have improved the short- and long-term outcomes of patients undergoing catheter-based coronary interventions. However, the use of these devices in complex coronary lesions has also created an incessant form of in-stent restenosis that still defies treatment. Plaque burden has been consistently and reproducibly recognized as an important factor that may incite neointimal proliferation after stent implantation. Prospective nonrandomized experience has shown that plaque removal prior to stent implantation using directional atherectomy is a promising approach to reduce restenosis in selected patients. However, the proof of concept awaits the results of the randomized trials. Ultimately, the clinical use (safety and efficacy) of this approach will depend on 1) further improvements on the current directional atherectomy device to make it user friendly; 2) minimizing the incidence of non-Q-wave myocardial infarction with selective use of IIb-IIIa platelet receptor antagonists or distal protection devices; and 3) targeting patients at high risk for restenosis in whom efficient debulking is feasible. This would include patients who have noncalcified lesions in vessels greater than 2.75 mm but less than 3.5 mm in diameter that require a long stent or multiple stents, aorto-ostial lesions, bifurcational lesions, and chronic total occlusions.

Journal Article↗
PubMed2000

Coronary stenting beyond standard indications. Immediate and follow-up results.

BACKGROUND: Coronary stent has become an accepted treatment modality for selected indications. However, the literature shows diverse results when indications for coronary stenting are different from those tested in large randomized trials. The purpose of this study was to determine immediate and follow-up clinical and angiographic results in patients treated with coronary stenting for indications not specifically tested in large randomized trials. METHODS: Coronary stents were implanted in a total of 2060 lesions (1757 patients) in seven groups with expanded indications: left main coronary lesions, calcified lesions, small vessels (< 3 mm in size), small vessels with diffuse disease, large vessels with diffuse disease, and bifurcation lesions treated with stents in both branches or with one stent implanted only in the major branch. Stents were implanted using high balloon pressure for final inflation and in most cases with intravascular ultrasound. Clinical follow-up was achieved in 96% of patients at a mean time of 12+/-7 months. RESULTS: Primary success (range 89-96%) and acute complications (range 5.7-13%) were comparable in all groups. At follow-up, the mortality rate was highest in the group of left main stenting (12.5%) but 20% of these patients had coronary stenting on non-elective basis. The restenosis rates ranged between 16-43%. The restenosis rate was highest in the group of bifurcation lesions with stent implantation in both vessels leading to a major adverse cardiac event (MACE) rate of 62% in this group. However, the survival rate at 1 and 2 years in the overall study group was 97 and 96%, and the event free survival was 76 and 74%, respectively. The procedure-related predictors of MACE were: final intravascular ultrasound result, use of stents with non-slotted tube morphology, final stent percent stenosis, and vessel size. CONCLUSIONS: Coronary stenting beyond standard indications is feasible, with acceptable primary success and complication rates. However, the overall MACE rates were relatively high (34-62%), in particular for the indication of bifurcation lesions with stents implanted in both vessels.

Age Factors↗
PubMed2000

Surgical and percutaneous myocardial angiogenesis induction. Part I--laser revascularization.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable in a subset of patients with angina refractory to medical treatment. Bypass surgery may not be feasible because of lack of suitable conduits, diffuse coronary artery disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. Transmyocardial laser revascularization and the stimulation of neoangiogenesis by a variety of growth factors have recently emerged as a new tool in the management of these patients. In the first part of this article, we review laser-induced direct myocardial revascularization, its indications, potential risks, and published clinical trials. The induction of neoangiogenesis using different growth factors or the genes encoding for them will be the subject of the second part of our review.

Angina Pectoris↗
PubMed2000

Endovascular treatment of a noninfected anastomotic juxtarenal aortic aneurysm.

An 82-year-old man underwent an endovascular procedure with a commercially available endovascular graft for an anastomotic juxtarenal abdominal aortic aneurysm. The anastomotic aneurysm, which showed no sign of infection, developed 4 years after implantation of an aortic end-to-end graft for an infrarenal aortic aneurysm. The aneurysm was diagnosed during routine ultrasonographic follow-up; there was no apparent infection of the graft. Aortography confirmed the diagnosis and also revealed a small pseudoaneurysm at the level of the distal aortic anastomosis. Endovascular surgery was performed in the operating room with the guidance of C-arm fluoroscopy and intravascular ultrasound. Two Vanguard Straight Endovascular Aortic Graft Cuffs (26 x 50 mm and 24 x 50 mm) were implanted, successfully excluding both the anastomotic juxtarenal aortic aneurysm and the distal pseudoaneurysm. The renal arteries were preserved and no early or late endoleaks were observed. The patient was discharged 2 days after the procedure. Sixteen months later, he was alive and well, with no endovascular leakage, no enlargement of the aortic aneurysms, and no sign of infection. In our opinion, this experience shows that commercially available endovascular grafts may be used successfully to treat anastomotic aortic aneurysms and pseudoaneurysms.

Aged↗
PubMed2000

The effect of ethnicity and age on palatal size and shape: a study in a northern Chilean healthy population.

Race and ethnicity influence the form of the human craniofacial complex in varying ways. The aim of the present investigation was to quantify the effects of ethnicity (mestizos, Aymara, non-Aymara), age (adolescents and adults), and sex on the form (size and shape) of the hard palate in normal Native American individuals. From the dental casts of 51 individuals with a complete permanent dentition, the x, y, and z coordinates of several standardized palatal landmarks were obtained with a computerized 3-dimensional digitizer. Palatal landmarks were used to derive a mathematical equation for palatal shape in the frontal and sagittal planes. Palatal width and length, frontal and sagittal heights, sagittal slope, and deviation of the raphe from the midline were also calculated. In the Aymara subjects, there was no effect of sex on palatal size, but there was an effect on palatal shape independent of size, especially with respect to male growth. Indeed, female palates apparently did not change their shape between adolescence and adulthood, while male palates increased their posterior "height." Overall, the 3 ethnic groups appeared to possess similar palatal size, with small significant differences. In the adult individuals, ethnicity did not seem to influence palatal shape. In contrast, adolescent males showed differences: non-Aymara subjects had the "highest" palatal shape, Aymara the "lowest," and mestizos an intermediate position. In conclusion, ethnicity does not seem to be a factor of major variability of human hard palate morphology, at least in the present 3 northern Chilean groups, as already found for dental arch shape. Age probably has a larger effect, particularly in the posterior part of the palate, where the eruption of the second and third molars between adolescence and young adulthood may play a role. A further development of the present investigation may involve larger samples of individuals from different ethnic groups.

Adolescent↗
PubMed1999

Short- and long-term evolution of unstented nonocclusive coronary dissection after coronary angioplasty.

OBJECTIVES: We assessed the short- and long-term clinical and angiographic outcome of nonocclusive unstented dissection after percutaneous transluminal coronary angioplasty (PTCA) and its correlation with restenosis. BACKGROUND: The use of stents has dramatically increased both the number and the cost of coronary revascularization procedures. However, this technique is not completely risk free, and its benefits have not been fully demonstrated in uncomplicated dissections. METHODS: We studied 129 consecutive patients with 49 nonocclusive dissections after PTCA (grades A to D of National Heart, Lung, and Blood Institute classification) and good distal flow (TIMI [Thrombolysis in Myocardial Infarction] flow grade 3). All patients underwent coronary angiography at 24 h and at six months post-PTCA. Clinical status was assessed every three months in the outpatient clinic. Study subjects were matched with 60 other patients in whom stenting was performed for the presence of dissection. RESULTS: In the former group, all but two patients (with type E dissection, which evolved to coronary occlusion and myocardial infarction) improved their dissection score during follow-up: at six months only 18 dissections were still angiographically visible, and no clinical adverse events were recorded. In the dissected vessels, the restenosis rate was significantly lower than in those without dissection (12% vs. 44%, p < 0.001); in the stented vessels, the restenosis rate was 25% (15/60). CONCLUSIONS: In the presence of TIMI flow grade 3, coronary dissection is associated with a favorable outcome and predicts a low restenosis rate. These results caution against the indiscriminate use of intravascular prostheses in the event of nonocclusive coronary dissection.

Adult↗
PubMed1999

Comparison of immediate and follow-up results of the short and long NIR stent with the Palmaz-Schatz stent.

The intrinsic characteristics of a stent including stent length may affect both procedural success and long-term outcome. The present study evaluated the immediate and follow-up results after implantation of the short and long NIR stent and compared these results with the Palmaz-Schatz stent. Between July 1995 and December 1996, stenting with a 16-mm NIR stent (NIR-16), a 32-mm NIR stent (NIR-32), or a Palmaz-Schatz stent (PS) was performed in 68, 57, and 155 lesions, respectively. There were no significant differences in the incidences of delivery failure (PS, 2.6%: NIR-16, 4.4%; NIR-32, 5.3%; p = NS) and procedural success (PS, 92%; NIR-16, 93%; NIR-32, 93%; p = NS) among the 3 groups. The reference vessel diameter was smaller in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz stent (PS, 3.14+/-0.58, NIR-16, 3.00+/-0.50; NIR-32, 2.90+/-0.47 mm; p <0.05). The lesion length was longer in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 8.9+/-5.0; NIR-16, 11.0+/-4.1; NIR-32, 26.1+/-9.7 mm; p <0.01). After the procedure, the lesions with a 32-mm NIR stent had a smaller minimal lumen diameter than those with a Palmaz-Schatz stent (PS, 3.17+/-0.61; NIR-16, 2.99+/-0.51; NIR-32, 2.89+/-0.49 mm; p <0.01). At follow-up, a smaller minimal lumen diameter was observed in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 2.32+/-0.98; NIR-16, 2.25+/-0.80; NIR-32, 1.68+/-0.79 mm; p <0.01). Restenosis rates were 16.5% in lesions with a Palmaz-Schatz stent, 13.3% in those with a 16-mm NIR stent, and 47.4% in those with a 32-mm NIR stent (p <0.01). Although stent delivery and procedural success of a long NIR stent were acceptable, the restenosis rate of a long NIR stent was high compared with a short NIR stent or a Palmaz-Schatz stent.

Adult↗
PubMed1999

Prevention of distal embolization during saphenous vein graft lesion angioplasty. Experience with a new temporary occlusion and aspiration system.

BACKGROUND: Repeat coronary artery bypass graft surgery (CABG) is associated with a high morbidity and mortality, rendering percutaneous treatment of saphenous vein graft (SVG) lesions an attractive alternative. However, percutaneous interventions of degenerated SVGs carries high risk of distal embolization. METHODS AND RESULTS: This study reports our initial experience with the PercuSurge GuardWire, a new device developed to prevent embolization during treatment of degenerated SVG. This device consists of a 190-cm-long, hollow 0.014-in guidewire with a central lumen connected to a distal occlusion balloon. A dedicated inflation device (the MicroSeal Adapter) was used to inflate the distal balloon and maintain complete lumen occlusion during balloon dilatation and stent implantation. A monorail aspiration catheter, connected to a vacuum syringe, was used to evacuate atherosclerotic and thrombotic debris. Angioplasty with stent implantation was performed in 15 degenerated SVGs (18 lesions). Procedural success was achieved in all patients with normal postprocedure flow (Thrombolysis in Myocardial Infarction grade 3). No distal embolization was observed. There were no major in-hospital adverse clinical events, including Q-wave or non-Q-wave myocardial infarction, emergency CABG, or death. All patients were asymptomatic at discharge. CONCLUSIONS: This preliminary series supports the feasible use of the PercuSurge GuardWire for retrieval of plaque debris and prevention of embolization in degenerated SVGs. The good tolerance of temporary occlusions without angiographic or clinical evidence of distal embolization represents encouraging early findings.

Aged↗