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Biomedical subjects

N Corvaja

Publications and source records attributed to N Corvaja.

At least 19 recordsLinked to original sources
PubMed2005

Treatment of bifurcation lesions with two stents: one year angiographic and clinical follow up of crush versus T stenting.

OBJECTIVES: To compare long term outcomes of the crush versus the T technique in bifurcation lesions. DESIGN: 182 consecutive patients were identified who underwent percutaneous coronary interventions for bifurcation lesions with drug eluting stents between April 2002 and January 2004. Two techniques were used according to the operator's discretion: crush (group C, n = 121) or T (group T, n = 61). RESULTS: In-hospital outcome differed significantly between the two groups. Angiographic follow up was available for 142 (78%) patients. Groups C and T did not differ significantly regarding late loss (0.42 (0.39) mm v 0.34 (0.35) mm, p = 0.52) and rate of restenosis (16.2% v 13.0%, p = 0.80) in both the main and the side branch without final kissing balloon post-dilatation. However, when final kissing balloon post-dilatation was performed, group C had significantly lower late lumen loss (0.23 (0.21) mm v 0.37 (0.33) mm, p = 0.02) and restenosis rate (8.6% v 26.5%, p = 0.04) in the side branch. At one year's clinical follow up, group C compared with group T had lower rates of target lesion revascularisation (14.0% v 31.1%, p = 0.01) and target vessel revascularisation (16.5% v 32.8%, p = 0.02). CONCLUSIONS: In non-selected bifurcation lesions treated with drug eluting stents, the restenosis rate remains relatively high in the side branch. Compared with the T stenting technique, crush stenting with kissing balloon post-dilatation is associated with a reduced rate of restenosis in the side branch.

Catheterization↗
PubMed2004

The use of drug eluting stents in single and multivessel disease: results from a single centre experience.

OBJECTIVE: Drug eluting stents have been shown to reduce the rate of in-stent restenosis in cases where single lesions are treated. The performance of these stents, in patients with multivessel disease and complex lesions, however, remains unknown. Our experience with sirolimus eluting stents in such patients is presented. DESIGN AND PATIENTS: This study includes all consecutive patients treated at San Raffaele Hospital and EMO Centro Cuore Columbus, Milan, Italy treated with sirolimus eluting stents. RESULTS: Between April 2002 and March 2003, 486 patients with 1027 lesions were treated (437 males, 49 females) with a mean (SD) age of 62.2 (10.5) years. Of all patients studied, 19.1% had single vessel disease, 33.8% had two vessel disease, and 47.1% had three vessel disease. Of the whole study group, 20.3% of patients had diabetes mellitus. A mean (SD) of 2.3 (0.4) stents per patient and 1.1 (0.2) stents per lesion were implanted. The baseline mean reference diameter was 2.7 (0.6) mm with a mean minimal luminal diameter of 0.9 (0.5) mm. Post-stenting, the acute gain was 1.8 (0.6) mm. During hospital stay one patient died (0.2%) and 13 (2.7%) patients had in-hospital myocardial infarction (MI). One patient required urgent repeat percutaneous coronary intervention. Six months clinical follow up was performed in all 347 eligible patients. Six months mortality was 2.0% (n = 7) and acute MI occurred in 0.3% (n = 1). Target lesion revascularisation occurred in 9.5% (n = 33) of the patients and target vessel revascularisation (TVR) in 11.5% (n = 40) of the patients. Major adverse cardiac event rate was 13.8% (n = 48). TVR was 4.5% for single vessel disease and 13.2% for multivessel disease. Diabetes mellitus was the only significant predictor for TVR. CONCLUSION: The use of drug eluting stents in single and multivessel coronary disease produces good short and medium term results with a low rate of revascularisation. Longer term follow-up is required to confirm these observations.

Adult↗
PubMed2002

Carotid artery stenting in the first 100 consecutive patients: results and follow up.

BACKGROUND: Carotid artery stenting is now used as an alternative to surgical endarterectomy. The availability of cerebral protection systems has expanded the area of application of this procedure. OBJECTIVE: To assess the feasibility, safety, and immediate and late clinical outcome in patients undergoing percutaneous carotid interventions. METHODS: Between January 1999 and December 2000, 100 consecutive patients with 102 carotid artery stenoses were treated (71 men, 29 women, mean (SD) age 67 (8) years): 49 had coronary artery disease, 28 had previous stroke or transient ischaemic attack (TIA). On the basis of the Mayo Clinic carotid endarterectomy risk scale, 73 patients were grade III-IV and 13 grade VI. RESULTS: Baseline diameter stenosis was 78.8 (10)%, with a mean lesion length of 12.6 (5.8) mm. Angiographic success was obtained in 99 lesions (97.0%) with a final diameter stenosis of 2.4 (3.5)%. Procedural success was obtained in 96 patients (96%). Selective cannulation of three carotid arteries was impossible owing to severe vessel tortuosity. Carotid stenting was performed in 97 of the treated lesions, and protection devices were used in 67 lesions. In-hospital complications occurred in seven patients (six TIA, one (category 1) minor stroke). No major stroke or death occurred. All patients were discharged from the hospital after an average of 2.5 days. At 12 (6.2) months of follow up restenosis occurred in three patients (3.4%) (one patient with carotid occlusion had TIA). Six patients had died: two from cerebrovascular events (5 and 11 months after the procedure) and four from cardiovascular causes. CONCLUSIONS: Carotid stenting appears feasible and safe, with few major complications. Long term follow up is affected by a high incidence of cardiovascular mortality.

Adult↗
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

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

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

Assessment of the functional significance of coronary lesions using a monorail catheter.

Myocardial fractional flow reserve (FFR) < 0.75 is a reliable index of a functionally severe coronary stenosis. FFR is best assessed by a sensor-tipped pressure monitoring guidewire (PW). The purpose of this study was to assess whether a multifunctional probing catheter (MFP), a 3 French dual-lumen monorail catheter, can be used to accurately measure intracoronary pressure and FFR. In 35 lesions (35 patients; learning group), we calculated FFR by both PW (FFRPW) and MFP (FFRMFP). Using ROC analysis, the FFRMFP value of 0.65 had the highest sensitivity with the FFRPW < 0.75. FFRMFP cut-off (0.65) was tested in 40 patients (testing group). In all cases, lumen diameter was documented by an intracoronary ultrasound examination. In the learning group, the FFRPW was 0.82 +/- 0.17 and FFRMFP was 0.70 +/- 0.23 (r = 0.88; p < 0.001). The FFRMFP cut-off value (0.65) correctly predicted the FFRPW in 37/40 cases in the testing group. In the 3 discordant cases, FFR was critical (< 0.65) by MFP and normal (> 0.75) by PW. In all these cases, minimal lumen cross-sectional area was < 2.8 mm2. When FFRMFP is > 0.65, FFRPW is always > 0.75. These data demonstrate that even with larger cross-sectional area than a pressure wire, the MFP catheter can easily and reliably be used to assess the functional severity of coronary stenosis.

Cardiac Catheterization↗
PubMed2000

Edge restenosis after implantation of high activity (32)P radioactive beta-emitting stents.

BACKGROUND: A high restenosis rate has been reported at the edges ("edge restenosis") of (32)P radioactive stents with an initial activity level of 3 to 12 microCi. This edge effect might be due to balloon injury and to a low dose of radiation at the stent margins. The aim of this study was to evaluate whether the implantation of (32)P radioactive stents with a higher activity level (12 to 21 microCi) combined with a nonaggressive stent implantation strategy could solve the problem of edge restenosis. METHODS AND RESULTS: We compared the results of lesions treated with single radioactive BX stents with an activity of 12 to 21 microCi (group 2, n = 54 lesions) with the results of lesions treated by single radioactive BX stents with an initial activity level of 3 to 12 microCi (group 1, n = 42 lesions). There were no procedural events. At the 6-month follow-up, no myocardial infarctions, deaths, or stent thromboses had occurred. Intrastent binary restenosis was 0% in group 1 versus 4% in group 2 (n = 2, both at the ostium of the right coronary artery, P = NS). Intrastent neointimal hyperplasia was significantly lower in group 2 than in group 1. The intralesion (intrastent plus peri-stent) restenosis rate was 38% in group 1 versus 30% in group 2 (P = NS). Conclusions-Single (32)P radioactive stents with an initial activity level of 12 to 21 microCi reduced intrastent neointimal hyperplasia compared with stents of 3 to 12 microCi, but they did not solve the problem of edge restenosis, even if a nonaggressive stent implantation strategy was used.

Angioplasty, Balloon, Coronary↗
PubMed2000

Cutting balloon angioplasty for the treatment of in-stent restenosis.

The results using the Cutting Balloon for the treatment of in-stent restenosis may be superior to those of conventional percutaneous transluminal coronary angioplasty (PTCA) or even the combination of PTCA preceded by rotational atherectomy. The reasons for these possible differences are not yet well defined. The case we report suggests that the Cutting Balloon achieves a better final result than conventional PTCA, by making the tissue more amenable to being pushed outward through the stent struts.

Angioplasty, Balloon, Coronary↗
PubMed2000

Left internal mammary artery graft perforation repair using polytetrafluoroethylene-covered stents.

The increase in the use of the left internal mammary artery (LIMA) as graft of choice to the left anterior descending coronary artery for conventional and minimally invasive coronary artery bypass surgery has led to an increased incidence of LIMA pathologic lesions early after surgery. The lesion, commonly located in the body of the LIMA graft, is usually caused by mechanical injury during harvesting of the vessel. In this context, percutaneous intervention with stent implantation can be complicated by vessel rupture, which usually requires emergency surgical repair. We describe two cases of stent implantation in newly placed LIMA grafts complicated by vessel rupture, which were successfully repaired using polytetrafluoroethylene-covered stents.

Aged↗
PubMed2000

Bifurcation lesions: two stents versus one stent--immediate and follow-up results.

OBJECTIVES: The purpose of this study was to evaluate two different techniques of stent placement in bifurcation lesions. BACKGROUND: Although stent placement with dedicated techniques has been suggested to be a useful therapeutic modality for bifurcation lesions, limited information is available if stent placement on the side branch and on the parent branch provides any advantage over a simpler strategy of stenting the parent vessel and balloon angioplasty of the side branch. METHODS: Between March 1993 and April 1999, we treated a total of 92 patients with bifurcation lesions with two strategies: stenting both vessels (group B, n = 53) or stenting the parent vessel and balloon angioplasty of the side branch (group P, n = 39). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained. RESULTS: Stent placement on both branches resulted in a lower residual stenosis (7.4 +/- 10.9% vs. 23.4% +/- 18.7%, p < 0.001) in the side branch. Acute procedural success was similar in the two groups (group B: 87% vs. Group P: 92%). In-hospital major adverse cardiac events (MACE) occurred only in group B (13% vs. 0%, p < 0.05). At the six-month follow-up, the angiographic restenosis rate (group B: 62% vs. Group P: 48%) and the target lesion revascularization rate (38% vs. 36%, respectively) were similar in the two groups. There was no difference in the incidence of six-month total MACE (51% vs. 38%). CONCLUSIONS: For the treatment of true bifurcation lesions, a complex strategy of stenting both vessels provided no advantage in terms of procedural success and late outcome versus a simpler strategy of stenting only the parent vessel.

Aged↗
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

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↗
PubMed1995

Effects of sleep deprivation on the postnatal development of visual-deprived cells in the cat's lateral geniculate nucleus.

1. Observations made by Wiesel and Hubel in kittens during the critical period have shown that monocular visual deprivation (MD) produces hypotrophic changes in the deprived layers of the LGN. Since, in addition to retinal inputs, the LGN also receives extraretinal inputs which are particularly active during REM sleep (a phase which is highly represented at birth), we performed experiments to find out whether total sleep deprivation (SD) interferes with the neuronal maturation in the LGN, thus modifying the susceptibility of LGN neurons to MD. 2. Ten groups of twin kittens were submitted to eyelid suture of one side at the age of 12 to 42 days after birth, and maintained into MD for periods of time which produced only slight or negligible changes in the deprived LGN layers. However, one of the twins in each group was allowed to sleep, while the other was submitted to 2 to 6 days of SD obtained by gentle handling during the last period of MD. At the end of the experiments cross-sectional areas of cell bodies were measured in the binocular segment of different layers of the LGN of both sides, at comparable levels. 3. MD, started 25 to 42 days after birth and continued for 11 to 23 days produced a slight but significant reduction of the mean cell area in the visual-deprived magnocellular ventral (C) and/or dorsal (A) layers of the contralateral LGN, but not in the middle (A1) layer of the ipsilateral LGN. This shrinkage, however, was most severe and involved also the layer A1 if kittens were also submitted to 5-6 days of SD during the last period of MD. There was also a tendency towards increased size in the nondeprived geniculate layers, probably due to an increased monocular visual experience resulting from an increased wake time in the light. However, the slight increase in cell size seen in these layers contrasted with the prominent increase in shrinkage of the visual-deprived layers after SD, indicating that this finding might have resulted from removing an influence of sleep. The effects of SD appeared to depend on the age of kittens (critical period) and the duration of MD. 4. In conclusion, shortly after birth, SD enhanced the structural abnormalities produced by monocular eyelid closure in the visual-deprived LGN layers. Since rhythmic discharges of pontine structures impinge on the LGN neurons during REM sleep, it is postulated that they could represent an endogenous source of stimulation leading to periodic read out of the synaptic connections between primary optic fibers and LGN neurons. This extraretinal input may thus collaborate with the retinal input to facilitate neuronal maturation of the LGN. The possibility that specific noradrenergic and cholinergic neurons, normally acting on the visual system during the sleep-waking cycle, intervene in the postnatal development of the LGN neurons has been discussed.

Animals↗