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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 55 records · Page 3Linked to original sources
PubMed2001

Intravascular ultrasound-guided percutaneous transluminal coronary angioplasty with provisional spot stenting for treatment of long coronary lesions.

OBJECTIVES: The purpose of this study was to evaluate the approach of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with spot stenting (SS) for the treatment of long coronary lesions. BACKGROUND: Treating long coronary lesions with balloon angioplasty results in suboptimal short- and long-term outcomes. Full lesion coverage with traditional stenting (TS) has been associated with a high restenosis rate. METHODS: We prospectively evaluated a consecutive series of 130 long lesions (>15 mm) in 101 patients treated with IVUS-guided PTCA and SS. The results were compared with those of TS in a matched group of patients. Coronary angioplasty was performed with a balloon to vessel ratio of 1:1, according to the IVUS media-to-media diameter of the vessel at the lesion site, to achieve prespecified IVUS criteria: lumen cross-sectional area (CSA) > or =5.5 mm(2) or > or =50% of the vessel CSA at the lesion site. The stents were implanted only in the vessel segment where the criteria were not met. RESULTS: In the SS group, stents were implanted in 67 of 130 lesions, and the mean stent length was shorter than that of lesions in the matched TS group (10.4 +/- 13 mm vs. 32.4 +/- 13 mm, p < 0.005). The 30-day major adverse cardiac event (MACE) rate was similar (5%) for both groups. Angiographic restenosis was 25% with IVUS-guided SS, as compared with 39% in the TS group (p < 0.05). Follow-up MACE and target lesion revascularization rates were lower in the SS group than in the TS group (22% vs. 38% [p < 0.05] and 19% vs. 34% [p < 0.05], respectively). CONCLUSIONS: Intravascular ultrasound-guided SS for the treatment of long coronary lesions is associated with good acute outcome. Angiographic restenosis and follow-up MACE rates were significantly lower than those with TS.

Aged↗
PubMed2001

Long-term clinical outcomes after unprotected left main trunk percutaneous revascularization in 279 patients.

BACKGROUND: Percutaneous coronary revascularization (PCI) has been increasingly applied to unprotected left main trunk (LMT) lesions, with varied long-term success. This study attempts to define the predictors of outcome in this population. METHODS AND RESULTS: Two hundred seventy-nine consecutive patients who had LMT PCI at 1 of 25 sites between 1993 and 1998 were studied. Forty-six percent of these patients were deemed inoperable or at high surgical risk. Thirty-eight patients (13.7%) died in hospital, and the rest were followed up for a mean of 19 months. The 1-year incidence was 24.2% for all-cause mortality, 20.2% for cardiac mortality, 9.8% for myocardial infarction, and 9.4% for CABG. Independent correlates of all-cause mortality were left ventricular ejection fraction </=30%, mitral regurgitation grade 3 or 4, presentation with myocardial infarction and shock, creatinine >/=2.0 mg/dL, and severe lesion calcification. For the 32% of patients <65 years old with left ventricular ejection fraction >30% and without shock, the prevalence of these adverse risk factors was low. No periprocedural deaths were observed in this low-risk subset, and the 1-year mortality was only 3.4%. CONCLUSIONS: Patients undergoing unprotected LMT PCI have frequent serious comorbidities and consequently have high event rates. PCI may be an alternative to CABG for a select proportion of elective patients and may also be appropriate for highly symptomatic inoperable patients. Meticulous follow-up of hospital survivors is required because of the rather high mortality during the first few months after treatment.

Aged↗
PubMed2001

Cerebral protection with filter devices during carotid artery stenting.

BACKGROUND: Distal embolization of debris during percutaneous carotid artery stenting may result in neurological deficit. Filter devices for cerebral protection potentially reduce the risk of embolization. METHODS AND RESULTS: Elective carotid stent implantation using 3 different types of distal filter protection devices was attempted in 88 consecutive lesions (84 patients) in the internal carotid artery that had >70% diameter stenosis (mean, 78.7+/-10.7%). Procedures were performed in 3 different centers. The mean age of the patients was 69+/-8 years, 75% were men, and 35.7% had neurological symptoms. In 86 lesions, a stent was successfully implanted (97.7%). In 83 of these 86 procedures (96.5%), it was possible to position a filter device. In 53% of filters, there was macroscopic evidence of debris. Collected material consisted of lipid-rich macrophages, fibrin material, and cholesterol clefts. Neurological complications during the procedure, in the hospital, and at 30 days of clinical follow-up occurred in only one patient (1.2%). This patient suffered a minor stroke that resolved within 1 week. Two major adverse cardiac events (2.3%) occurred during the 30 days of follow-up. CONCLUSIONS: Filter protection during carotid artery stenting seems feasible and safe. In the present series, the incidence of neurological complications was low.

Aged↗
PubMed2001

Emergency stenting to treat neurological complications occurring after carotid endarterectomy.

OBJECTIVES: The purpose of this study was to assess the efficacy of emergency stent implantation for the treatment of perioperative stroke after carotid endarterectomy (CEA). BACKGROUND: Carotid endarterectomy has been proven safe and effective in reducing the risk of stroke in symptomatic and asymptomatic patients with >60% carotid artery stenosis. However, perioperative stroke has been reported in 1.5% to 9% of CEA cases. The management of such a complication is challenging. Recently, percutaneous transluminal carotid angioplasty with stent deployment has emerged as a valuable and alternative strategy for the treatment of carotid artery disease. METHODS: Between April 1998 and February 2000, 18 of the 995 patients (1.8%) who had CEA in our institution experienced perioperative major or minor neurological complications. Of these, 13 patients underwent emergency carotid angiogram and eventual stent implantation, whereas the remaining five had surgery re-exploration. RESULTS: Carotid angiogram was performed within 20+/-10 min and revealed vessel flow-limiting dissection (five cases) or thrombosis (eight cases). Percutaneous transluminal carotid angioplasty with direct stenting (self-expandable stent) was performed in all 13 cases. Angiographic success was 100%. Complete remission of neurological symptoms occurred in 11 of the 13 patients treated by stent implantation and in one of the five patients treated by surgical re-exploration (p = 0.024). CONCLUSIONS: Stent implantation seems to be a safe and effective strategy in the treatment of perioperative stroke complicating CEA, especially when carotid dissection represents the main anatomic problem.

Aged↗
PubMed2001

Predictors of diffuse and aggressive intra-stent restenosis.

OBJECTIVES: This study was performed to investigate the causes of diffuse and aggressive intra-stent restenosis. BACKGROUND: Although restenosis is usually considered to be a dichotomous variable, there is clinical relevance to the severity of restenosis. It is not known which variables are predictive of diffuse or aggressive intra-stent restenosis. METHODS: A consecutive series of 456 coronary lesions with in-stent restenosis was evaluated for the type of restenosis using quantitative coronary angiography. Restenosis was defined as > or = 50% diameter stenosis at follow-up angiography, diffuse restenosis as a follow-up lesion length > or = 10 mm and aggressive restenosis as either an increase in lesion length from the original lesion or a restenotic narrowing tighter than the original. Clinical, anatomic and procedural characteristics were evaluated for lesions associated with these types of restenosis. RESULTS: Diffuse restenosis was associated with a smaller reference artery diameter, longer lesion length, female gender, longer stent length and the use of coil stents. Aggressive restenosis was more common in women, with the use of Wallstents and with long stent to lesion length ratios. Aggressive restenosis occurred earlier and was more closely associated with symptoms and myocardial infarctions than nonaggressive restenotic lesions. CONCLUSIONS: Markers for diffuse restenosis were also important markers for the presence of any restenosis. A long stent to lesion length ratio is an important marker for aggressive restenosis. When severe forms of in-stent restenosis occur, they tend to present earlier and with more symptoms, including myocardial infarction. More careful consideration of the type of in-stent restenosis may aid in identifying when alternative strategies may be useful.

Coronary Angiography↗
PubMed2001

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.

Cardiac Catheterization↗
PubMed2001

Directional atherectomy prior to stenting in bifurcation lesions: a matched comparison study with stenting alone.

The ideal catheter-based intervention for treatment of coronary lesions at bifurcation site still has to be defined. The aim of the study was to assess the acute and long-term outcome after treatment of bifurcation lesions with directional atherectomy (DCA) and stenting in comparison with stenting alone. Thirty-one consecutive patients treated for bifurcation coronary lesions (62 lesions) with DCA and stenting in at least one branch (DCA group) were compared with a matched group of 31 patients with bifurcation coronary lesions (62 lesions) treated with stenting alone in at least one branch (non-DCA group). Procedural success was 87.1% in the DCA group compared with 100% in the non-DCA group (P = 0.03). In-hospital major adverse cardiac events (MACE) occurred only in the DCA group (12.9% vs. 0%, P = 0.03), mainly non-Q-wave myocardial infarction. After the procedure, minimum lumen diameter (MLD) and acute gain were significantly greater (P = 0.004 and P = 0.05, respectively) and % diameter stenosis was significantly lower (P = 0.05) in the main branch in the DCA group. At follow-up angiogram, MLD in the main branch was still significantly greater in the DCA group compared to the non-DCA group (2.31 vs. 1.65, respectively, P = 0.04), with no significant difference in late loss and loss index between the two groups. Restenosis rate was 28.8% in the DCA group vs. 43.5% in the non-DCA group (P = 0.13). The incidence of follow-up MACE was 29% in the DCA group compared with 48.4% in the non-DCA group, mainly due to target lesion revascularization. In conclusion, treatment of bifurcation coronary lesions with DCA and stenting was associated with greater acute gain after the procedure and greater MLD at follow-up in the main branch compared with stenting alone. Procedural myocardial infarction was more frequent in the DCA group. Restenosis rates and follow-up MACE were lower following DCA and stenting, without reaching any statistical significance.

Adult↗
PubMed2001

Brachytherapy for in-stent restenosis through the internal mammary artery.

We report five cases treated with brachytherapy through the internal mammary artery (IMA) for in-stent restenosis at the distal anastomosis (n = 3) and in the left anterior descending coronary artery beyond the distal anastomosis (n = 2). After angioplasty, catheter-based gamma radiation was performed. There was no delivery failure of the radiation system. All cases had angiographic success and no procedural or in-hospital complications.

Aged↗
PubMed2001

Late acute thrombosis after coronary brachytherapy: when is the risk over?

Late total occlusion (LTO) after simultaneous coronary stenting and brachytherapy has been described in recent randomized trials. We report a case of LTO presenting with an acute clinical event 15 months after the index procedure, suggesting that the risk is not confined to the first 6-month to 1-year period.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Cutting balloon angioplasty for treatment of calcified coronary lesions.

The aim of the study was to evaluate the feasibility, safety, and efficacy of cutting balloon angioplasty in treatment of angiographically moderate and severe calcified coronary lesions. Thirty-seven calcified coronary lesions (29 patients) detected by angiography were dilated with cutting balloon. Predilatation with plain balloon was performed in 27 (73.0%) lesions and stent was implanted in 23 (62.2%) lesions following cutting balloon. Acute gain following cutting balloon in predilated lesions was compared to the acute gain following plain balloon predilatation. For predilated lesions, acute gain after cutting balloon was significantly greater compared with plain balloon predilatation (1.51 +/- 0.49 vs. 0.77 +/- 0.42; P = 0.01). This result was achieved with larger size and lower pressure of cutting balloon compared with plain balloon (3.28 +/- 0.46 vs. 2.94 +/- 0.55, P = 0.01; 10.38 +/- 1.64 vs. 13.19 +/- 3.63, P = 0.001, respectively). The final gain following cutting balloon dilatation was significantly higher than the expected gain obtained by using a plain balloon of the same size (1.51 +/- 0.49 vs. 0.93 +/- 0.48; P < 0.0001), which was inflated at significantly higher pressure compared with cutting balloon. When we compared acute gain following cutting balloon in lesions with and without predilatation, we found no significant difference (P = 0.31). Angiographic success was achieved in 36 (97.3%) lesions and procedural success in 33 (89.1%) lesions. In-hospital major adverse cardiac event (MACE) occurred in three (10.3%) patients. Follow-up MACE was reported from three (10.3%) patients. In conclusion, cutting balloon angioplasty is feasible and safe in treatment of angiographically moderate and severe calcified lesions. Dilating efficiency of cutting balloon seems to be greater compared with a plain balloon of the same size, which was inflated at significantly higher pressure compared with cutting balloon. These results can be achieved with low in-hospital MACE and are associated with a good long-term outcome.

Aged↗
PubMed2001

A phantom with tissue-like optical properties in the visible and near infrared for use in photomedicine.

BACKGROUND AND OBJECTIVE: Modeling of light transport in tissue requires development of theoretical models and experimental procedures, as well as tissue-simulating phantoms. Our purpose was to develop a phantom that matches the optical characteristics of human skin in the visible and near infrared spectral range. STUDY DESIGN/MATERIALS AND METHODS: The phantom consists of a transparent silicone rubber in which Al(2)O(3) particles and a cosmetic powder are embedded. Layers with thickness as thin as 0.1 mm can be made. The optical properties of Al(2)O(3) particles and cosmetic powder, i.e., total attenuation, absorption and scattering coefficients, and phase function, have been determined in the visible and near infrared spectral range, by using direct and indirect techniques. RESULTS: By varying the concentration of scattering and absorbing particles, tissue-like layers can be produced with predictable optical properties. In particular, mixing at suitable concentration Al(2)O(3) particles and cosmetic powder with the silicone rubber, the optical properties of human skin have been simulated over a range of wavelengths from 400 to 1,000 nm. The comparison between the phantom diffuse reflectance spectrum and that of human skin, averaged over a sample of 260 patients, showed a good agreement. CONCLUSION: The proposed technique allows to produce a stable and reproducible phantom, with accurately predictable optical properties, easy to make and to handle. This phantom is a useful tool for numerous applications involving light interaction with biologic tissue.

Culture Techniques↗
PubMed2001

Consolidation treatment with autologous peripheral blood progenitor cell transplantation in acute myeloid leukemia: a single center experience.

Several trials have suggested that intensive post-remission therapy may prolong the duration of complete remission (CR) in acute myeloid leukemia (AML). The purpose of this study was to evaluate the feasibility and the efficacy of high-dose cytarabine (HiDAC) consolidation chemotherapy followed by high-dose therapy and autologous infusion of peripheral blood progenitor cells (PBPC) mobilized by G-CSF in adult patients with AML in first CR. Fifteen consecutive AML patients underwent HiDAC consolidation chemotherapy, used as a method of in vivo purging, followed by G-CSF for the purpose of autologous PBPC collection. Eleven patients collected a median of 6.9x10(8)/kg peripheral blood mononuclear cells (MNC) (range 2.9-23) and a median of 6.67x10(6)/kg CD34+ cells (range 1.8-33.5) with a median of two aphereses (range 1-3). Two patients did not mobilize and two obtained an inadequate number of progenitor cells. The 11 patients with adequate collections received myeloablative chemotherapy followed by the infusion of PBPC. The median number of days to recover neutrophils and platelets was 12 and 13, respectively. After a median follow-up of 28.7 months (range 17.2-43.4), five out of 11 patients who underwent PBPC transplantation are still in CR, five have died in first relapse and one is alive in CR after relapse treated with salvage therapy and second PBPC infusion. These results demonstrate that HiDAC consolidation chemotherapy followed by autologous PBPC transplantation is a feasible procedure with minimal toxicity. Randomized studies should be performed to evaluate whether this form of consolidation may produce a significant improvement in leukemia-free survival.

Acute Disease↗
PubMed2001

A genetically determined high setting of TNF-alpha influences immunologic parameters of HLA-B8,DR3 positive subjects: implications for autoimmunity.

The 8.1 ancestral haplotype (AH) is a common Caucasoid haplotype carried by most people who type for HLA-B8,DR3. It seems unique in its association with a wide range of immunopathologic diseases. Healthy subjects bearing this haplotype demonstrate several alterations of immune response. This article will focus on the identification of the mechanism(s) of disease susceptibility of 8.1 AH. In 13 carriers of 8.1 AH, and 43 negative patients, enzyme immune assays serum levels of tumor necrosis factor (TNF)-alpha, soluble endothelial leukocyte adhesion molecule-1 (sELAM-1), cortisol, and interleukin(IL)-10 were determined. In addition, quantification of cytokine produced in vitro after mitogen stimulation was studied, and all subjects were genotyped for alleles at -592, -819, and -1082 nucleotides of IL-10 gene 5' flanking region, which is known to control IL-10 production. Results revealed that 8.1 AH is associated with a high in vivo and in vitro production of TNF-alpha, which in turn seems responsible for increased serum levels of sELAM-1, cortisol, and IL-10. On the contrary, in vitro production of IL-10 is not increased in these patients and there are no differences in allele promoter frequencies between the two groups that might explain the differences in IL-10 serum values. Thus, serum values seem to be the result of the effects of increased serum levels of TNF-alpha and cortisol. In conclusion, the increased spontaneous release of TNF-alpha, which modifies a certain number of immunologic parameters, may be the most characterizing feature of 8.1 AH. The consequent modification of the immunologic scenario might be involved in the predisposition to the impressive number of diseases and the changes in immune response observed in the patients studied.

Adult↗
PubMed2001

Heart rate variability and early recurrence of atrial fibrillation after electrical cardioversion.

OBJECTIVES: The study evaluated the role of the autonomic nervous system in atrial fibrillation (AF) recurrence. BACKGROUND: Early recurrence of AF after cardioversion (CV) is attributed to electrical remodeling. The possibility that an abnormal autonomic modulation might contribute to this phenomenon has not yet been adequately tested. METHODS: We analyzed short-term heart rate variability (HRV) in 93 patients with persistent AF and on chronic amiodarone treatment, after restoration of sinus rhythm by electrical CV. RESULTS: Two weeks later, 25 patients presented with AF. Spectral analysis of HRV revealed that patients wi

Aged↗
PubMed2001

Continued benefit of coronary stenting versus balloon angioplasty: five-year clinical follow-up of Benestent-I trial.

OBJECTIVES: This study sought to establish whether the early favorable results in the Benestent-I randomized trial comparing elective Palmaz-Schatz stent implantation with balloon angioplasty in 516 patients with stable angina pectoris are maintained at 5 years. BACKGROUND: The size of the required sample was based on a 40% reduction in clinical events in the stent group. Seven months and one-year follow-up in this trial showed a decreased incidence of restenosis and clinical events in patients randomized to stent implantation. METHODS: Data at five years were collected by outpatient visit, via telephone and via the referring cardiologist. Three patients in the stent group and one in the percutaneous transluminal coronary angioplasty (PTCA) group were lost to follow-up at five years. Major clinical events, anginal status and use of cardiac medication were recorded according to the intention to treat principle. RESULTS: No significant differences were found in anginal status and use of cardiac medication between the two groups. In the PTCA group, 27.3% of patients underwent target lesion revascularization (TLR) versus 17.2% of patients in the stent group (p = 0.008). No significant differences in mortality (5.9% vs. 3.1%), cerebrovascular accident (0.8% vs. 1.2%), myocardial infarction (9.4% vs. 6.3%) or coronary bypass surgery (11.7% vs. 9.8%) were found between the stent and PTCA groups, respectively. At five years, the event-free survival rate (59.8% vs. 65.6%; p = 0.20) between the stent and PTCA groups no longer achieved statistical significance. CONCLUSIONS: The original 10% absolute difference in TLR in favor of the stent group has remained unchanged at five years, emphasizing the long-term stability of the stented target site.

Angina Pectoris↗