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Biomedical subjects

K Wilczek

Publications and source records attributed to K Wilczek.

17 recordsLinked to original sources
PubMed2001

[Transcatheter closure of atrial septal defects in adults with the Amplatzer atrial septal occluder].

UNLABELLED: In many centres the Amplatzer Septal Occluder (ASO) (AGA Med. Corp. Minnesota, USA) has become the device of choice for secundum atrial septal defect (ASD) closure in children. Current trend towards transcatheter closure of ASD in children could be translated to adults and many patients (pts) may avoid the need of open heart surgery. Assessment the efficacy and complication of device occlusion of ASD in adults, using ASO. Between October 1997 and April 2001 transcatheter closure of ASD was attempted in 51 pts who fulfilled the inclusion criteria--significant shunt with sufficient rims of interatrial septum. Mean age of pts was 29 (16-63) y, mean ASD diameter assessed by transesophageal echocardiography (TEE) was 14.7 (7-24) mm, assessed during catheterization by balloon sizing (stretched diameter) was 20.2 (8-36) mm. There were 9 pts with multiple ASDs, 2 pts with aneurysm of interatrial septum and 2--after previous surgery (recanalization of ASD). The ASO devices were successfully implanted in all, but one pt. In one patient because of unstable position of ASO (floppy rims), device was removed and bigger one was applied during next session. In one case early embolization to abdominal aorta occurred, ASO was translocated to aortic arch with Dotter basket and removed from aorta during simultaneous surgical closure of ASD. Mean fluoroscopy time was 15 (4-50) min. The occlusion rate after 24 h was 90%, after 1 month (m) 92%, after 3 m 93.5%, after 1 year (y) 93.3% and after 2 y 93.3%. All residual shunts were trivial. There were no late complication. CONCLUSIONS: The excellent results of ASD closure with ASO in adults indicate this treatment as a method of choice in selected patients, but long term follow-up is necessary to state final judgement.

Adolescent↗
PubMed1999

[Troponin T--is it a marker of restenosis after transluminal percutaneous angioplasty in unstable angina patients?].

Troponin T (TpT) is a protein implicated in skeletal muscle contractions, including myocardium. It was shown that the presence of troponin TpT in unstable angina patients' blood is associated with poor prognosis. In the present study amongst 25 patients with unstable angina 12 were found to have TpT present in their blood. TpT concentration was higher in patients with III and IVo CCS symptoms in comparison with class I and IIo CCS symptoms: 0.207 +/- 0.275 and 0.144 +/- 0.186 ng/mL respectively (p = 0.053; nonparametric Kolmogorow-Smirnov test). Patients were subjected to percutaneous transluminal coronary angioplasty (PTCA). After 3 months of follow up 17 patients (the rest of them dropped out) were assigned to two groups: A (n = 8)--without and B (n = 9)--with clinical and electrocardiographic signs of restenosis. Retrospective analysis revealed the presence of TpT before PTCA in 6 group B patients and 2 group A patients. Relative risk of stenocardia recurrence was calculated as 2.25. TpT was present in the blood of 20 patients in the first 24 hours after PTCA, and group B patients had higher mean TpT concentration; that could result from reperfusion of more ischaemic myocardium. It seems that the presence of TpT in unstable angina patients' blood may be an important factor characterizing patients with more serious prognosis.

Angina, Unstable↗
PubMed1998

[Use of fourier row as a method for analyzing the course of circadian heart rate in patients with left ventricular ejection fraction impairment].

The circadian heart rate course was assessed in 3 groups of patients with left ventricular ejection fraction (LVEF) 10-15%, 20-25% and 30-35%. The study comprised 36 persons. In 9 patients heart failure was due to MI and in 17--to dilated cardiomyopathy. Those with atrial fibrillation, ventricular tachycardia, supraventricular tachycardia, diabetes, valvular heart diseases and with central system disorders were excluded from the study. Left ventricular ejection fraction was evaluated by echocardiography. Heart rate, calculated as a mean value every 5 minutes, was taken in patients during 24 hour recordings. For each patient separately, mean value of all measurement was calculated. Then a ratio of each actual value to the mean value was calculated. This ratio was defined as relative heart rate; [formula: see text] Circadian heart rate courses were approximated by Fourier row: [formula: see text]. The 24 harmonics were analyzed. Statistically significant differences in circadian courses were closed to amplitudes of 1st, 12th, 13th, 14th, 16th, 18th harmonics. Using test of variance homogeneity it has been demonstrated that variability of amplitudes of 12th and 17th harmonics as well as phase of 5th harmonic depend on left ventricular ejection fraction.

Adult↗
PubMed1997

Experimental study of thrombogenicity and foreign body reaction induced by heparin-coated coronary stents.

BACKGROUND: Results of recent randomized clinical trials have revealed a significant reduction in angiographic restenosis rate when adjunctive stenting was performed after conventional coronary balloon angioplasty. The thrombogenicity of metal stents, however, remains a concern. In the present study, we compare the thrombogenicity of heparin-coated coronary stents with that of bare metallic coronary stents. METHODS AND RESULTS: Thrombogenicity of metallic coronary stents (four heparin-coated and eight bare stents) was studied in a rat arteriovenous shunt model with the use of 125I-labeled fibrinogen and 51Cr-labeled platelets. Total clot weight after 30-minute follow-up was significantly lower in the heparin-coated stents compared with the bare stents (8.1 +/- 3.7 versus 25.8 +/- 4.6 mg; P < .001). Relative 125I and 51Cr activities in the stents were significantly higher in the bare stents than in the heparin-coated stents (125I, 1.03 +/- 0.43 versus 0.18 +/- 0.04, P = .003; 51Cr, 17.5 +/- 6.8 versus 4.4 +/- 1.0, P = .004). Subsequently, heparin-coated and bare stents were randomly implanted in the right coronary artery of 20 domestic pigs. Angiographic parameters were similar between both groups at baseline and after 6-week follow-up. Morphometry also did not show a significant difference in lumen area (bare, 1.03 +/- 0.83 mm2; heparin-coated, 1.12 +/- 0.73 mm2; P = NS) or neointimal hyperplasia (bare, 1.01 +/- 0.81 mm2; heparin-coated, 1.21 +/- 0.57 mm2; P = NS). CONCLUSIONS: Heparin coating of metallic coronary stents decreases their thrombogenicity but does not improve late vessel patency and neointimal hyperplasia at follow-up in a porcine coronary model.

Animals↗
PubMed1996

Concept of the homemade coronary stent: experimental results and initial clinical experience.

To defray the escalating cost of coronary stenting, we handmade a balloon expandable coil stent with stainless steel wire. Preliminary comparison with the Palmaz-Schatz stent showed that, when implanted in porcine iliac arteries, there was no difference in immediate angiographic results or in the degree of foreign body reaction at 6 wk. Subsequently, a total of 73 stents were implanted in 52 patients, either as a bailout device (54%) or for suboptimal angiographic results (46%). All but two implantations were successful. The postprocedural regimen consisted of heparin 1,000 IU/hr, aspirin 250 mg daily, and ticlopidine 500 mg daily. In-hospital complications were limited to two groin hematomas, one necessitating blood transfusion. Importantly, stent thrombosis was not observed. While 6-mo follow-up is pending, we already conclude that a balloon expandable coil stent can be handmade easily at low cost and implanted safely in patients.

Animals↗
PubMed1996

Local methylprednisolone inhibition of foreign body response to coated intracoronary stents.

BACKGROUND: When poly(organo)phosphazene coated metallic stents are implanted into normal coronary arteries of pigs a severe histolymphocytic and fibromuscular reaction is induced. Corticosteroids possess potent anti-inflammatory and immunosuppressive effects, they have been shown to decrease migration and functional capability of the cells of inflammation and they may stabilize lysosomal cell membranes. This study aims to evaluates the feasibility and efficacy of local corticosteroid delivery by implantation of methylprednisolone loaded coronary stents into coronary arteries of pigs. METHODS: Tantalum balloon expandable coronary stents were coated with poly(organo)phosphazene impregnated with 5 wt% methylprednisolone. Methylprednisolone release was calculated in vitro and then randomly either a methylprednisolone loaded stent or a plain polymercoated stent was implanted into the right coronary artery of 20 pigs. Quantitative coronary artery analysis was done before, immediately after and 6 weeks after stent implantation. The pigs were then killed and the stented arteries processed for histopathological and morphometric evaluation. RESULTS: In-vitro testing revealed that the methylprednisolone loaded stents, when incubated in physiological saline, released 96% of the drug within 24 h. Quantitative angiography of the implanted stents showed similar angiographic parameters in both treatment groups immediately after implantation, but, after 6 weeks of follow-up study the minimal luminal diameter of the stented arterial segment was considerably larger in the methylprednisolone-treated pigs than it was in the control pigs (2.74 +/- 0.34 versus 1.36 +/- 0.72 mm, P < 0.005) This angiographic finding was confirmed at post-mortem morphometry where the respective values for neointimal thickness were 0.99 +/- 0.28 and 1.74 +/- 0.84 mm (P < 0.02). CONCLUSIONS: Polymer coated stents can be loaded with methylprednisolone which inhibits the severe foreign-body reaction induced by the combination of overstretch injury and the poly(organo)phosphazene polymer coating of metallic stents.

Animals↗
PubMed1996

Local Angiopeptin Delivery Using Coated Stents Reduces Neointimal Proliferation in Overstretched Porcine Coronary Arteries.

BACKGROUND: Systemic administration of angiopeptin has been shown to inhibit myointimal thickening after arterial injury in several animal species. METHODS AND RESULTS: To explore to what extent high and long-lasting local concentrations of angiopeptin influence the healing process after vascular injury, tantalum balloon-expandable stents were first coated with a polymer loaded with angiopeptin 250 µg. Implantation of these stents in porcine coronary arteries resulted in tissue concentrations of 10.7 pg/ml wet weight in the stented arterial segment 24 hours after stent implantation, gradually declining to 2.0 pg/ml wet weight at day 8. Finally, 20 pigs were randomly treated with either an angiopeptin-loaded or a blank-coated stent. At baseline, the angiographic parameters were similar between both groups but, after 6 weeks, the minimal luminal diameter of the stented arterial segment was larger in the angiopeptin-treated pigs when compared to controls (2.20 +/- 0.57 mm vs 1.57 +/- 0.68 mm, p < 0.01) This angiographic finding was confirmed by post-mortem morphometry where the respective lumen area values were 1.00 +/- 0.54 mm2 and 0.43 +/- 0.28 mm2 (p < 0.01). CONCLUSION: Polymer coated stents can be loaded with angiopeptin, which after implantation in porcine right coronary arteries result in high local tissue concentrations gradually declining over more than 8 days. These high local concentrations inhibit myointimal proliferation induced by poly(organo)phosphazene coated overstretched stents.

Journal Article↗
PubMed1994

Intravascular ultrasound versus angiography for measurement of luminal diameters in normal and diseased coronary arteries.

Quantitation of coronary luminal diameter with a 20 MHz mechanically rotating intravascular ultrasound (IVUS) catheter was compared with orthogonal-view cineangiography by use of a semiautomated edge-detection algorithm in 48 patients undergoing coronary angioplasty. Quantitative comparison of 196 matched segments was attempted, but in only 174 (88.8%) was a direct comparison of the two techniques possible. In angiographically normal coronary arteries (46 segments) the correlation between the values obtained by quantitative coronary angiography (QCA) and those achieved by IVUS was excellent (r = 0.92, p < 0.0001). For mild stenoses (80 segments) the correlation coefficient was only fair (r = 0.467, p < 0.001). After percutaneous transluminal coronary angioplasty the correlation coefficient between IVUS and QCA data (48 segments) was very weak (r = 0.282, p < 0.05). In conclusion, coronary IVUS is feasible and safe and even for a limited range of coronary arterial narrowing, significant correlations between IVUS and QCA measurements of minimal lumen diameter were found. They were excellent in normal coronary arteries, moderate in mildly diseased arteries, and weak after balloon angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1993

[Analysis of usefulness for quantitative methods determining segmental mobility in assessing contrast ventriculography of the left ventricle].

The aim of this study was to compare two different quantitative methods used to determine left ventricular regional wall motions. Circumferential and radial methods were used to distinguish between normo- and hypokinesia of the 5 segments proposed by AHA for RAO position. One hundred ventriculograms were analyzed. Fifty cases with normal wall motion and ejection fraction greater than 55% were chosen as a base to enumerate normokinetic values of regional contractility. The other fifty cases represented hypokinesia of different segments. Respective values for the radial method were 61.42 vs 38.10 for antero-basal segment, 73.8 vs 58.5 for antero-lateral segment, 67.74 vs 42.5 for apical segment, 69.88 vs 47.70 for postero-lateral segment and 41.72 vs 33.4 for postero-lateral segment. The values obtained with the circumferential method were 12.27 vs 10.21, 20.06 vs 16.21, 22.19 vs 18.78, 17.08 vs 11.39 and 8.50 vs 8.15, respectively. These results suggest that the radical method allows to better differentiate between hypo- and normokinesia. Postero-basal segment proved to be most difficult to assess. Both methods fail to make a clear distinction in these cases.

Evaluation Studies as Topic↗
PubMed1991

[Percutaneous transluminal coronary angioplasty--personal experience].

Percutaneous transluminal coronary angioplasty was employed in a group of 178 patients (151 males and 27 females) aged 24 to 68 years (mean 42 +/- 12 years). Stable angina was diagnosed in 136 patients, unstable angina in 38, and an acute infarct in 4. In 150 patients there was one, in 25 two and in 5 patients 3 target stenoses. Lesions were localised in the left anterior descending artery in 130 cases, in the circumflex artery in 32 cases and in the right coronary artery in 49 cases. The attempts to dilate 78 stenoses with a fixed-wire, non-guided system was successful in 78% of cases. Success rate with the over-the-wire system was 85%. In total, we successfully dilated 173 patients, i.e. 82%. The highest success rate, 85%, was achieved in lesions localized in the left anterior descending artery and lowest in lesions localized in the left circumflex artery. Success rate in the groups with stable and unstable coronary artery disease was similar. Complications occurred in 6% of the cases. Experience of the operators involved in PTCA is an important factor influencing the success rate. In the first year of using this technique, good results were achieved in 48% of patients, in the second year in 63%. During the next two years 86% of the stenoses were successfully dilated.

Adult↗
PubMed1991

[Meningitis and encephalitis in the years 1983-1990. Clinical observations].

From 1983 to 1990, at the I Clinic of Infectious Diseases, Silesian Academy of Medicine in Bytom, 995 patients with meningitis and encephalitis were treated; the average age was 17.86 years. After cerebrospinal fluid (CSF) examinations the patients were divided into groups. The first group consisted of patients with suppurative meningitis and encephalitis (202-20.30%), the other group were patients with aseptic meningitis (309-31.06%), a separate group consisted of patients with mumps meningitis (484-48.06% cases). In the group with suppurative meningitis and encephalitis etiological agents were isolated (Gram stain smear and/or culture of CSF) in 50.99% of cases. The most common causes of suppurative neuroinfections were: Neisseria meningitides and Streptococcus pneumoniae (in 23.76% cases). The increasing number of bacteriological tests positive results was observed during the analyzed period. The etiology of aseptic inflammation diseases of the central nervous system was defined with the help of serologic blood tests in 10-15%, and serologic confirmation of mumps meningitis was as high as 80% of cases. In the group of purulent neuroinfections, during the 8-year observation, 36 deaths occurred (17.82% of these patients). The observed tendency of the death rate decrease is concerned to be a result of better microbiological diagnostics and the possibility of an early aimed antibiotic therapy.

Adolescent↗
PubMed1989

[Hearing loss in suppurative meningitis and encephalitis in our cases].

Seventeen cases of the suppurative meningitis complicated by hearing loss have been analysed clinically. Emphasis is on the possibility of such a complication in any case of the suppurative infection of CNS. The authors have shown the necessity of otolaryngological examinations in each patient, basing on their own experience and available literature. An early diagnosis and appropriate treatment produces complete recover or decreases the degree of hearing loss being a complication of the suppurative neuroinfections.

Adolescent↗
PubMed1989

[Suppurative meningitis and meningoencephalitis in patients over 60 years of age].

The course of purulent meningoencephalitis is described in 16 patients aged over 60 years. The observation showed that in these patients the pattern of the clinical manifestations was atypical and the course of the disease was very severe, leading to death in 56% of cases. The authors stress that in this age group the results of the treatment depend on possibly early diagnosis and beginning of adequate therapy.

Age Factors↗
PubMed1989

[Possibilities of echocardiographic evaluation of hemodynamic disorders in hypertrophic cardiomyopathy].

In a group of 59 patients with hypertrophic cardiomyopathy relationship between echocardiographic parameters (interventricular septal thickness, left ventrical diastolic diameter, presence of SAM, distribution of hypertrophy) and certain hemodynamic measurements (diastolic compliance, left ventricular end-diastolic pressure, intraventricular pressure gradient, mean wall thickness and left ventricular mass index) were assessed. Substantial elevation of left ventricular end-diastolic pressure (LVEDP greater than 20 mmHg) was significantly more prevalent among patients with small left ventricular diameter and gross septal hypertrophy. Extensive ventricular hypertrophy (Maron type III) was not characterized by any distinctive hemodynamic pattern. Presence of SAM reaching interventricular septum was indicative of left ventricular outflow obstruction.

Adolescent↗
PubMedDate not supplied

Comparison of self-expanding polyethylene terephthalate and metallic stents implanted in porcine iliac arteries.

PURPOSE: Comparison of the biocompatibility of self-expanding polyethylene terephthalate (PET) stents with self-expanding metallic stents (Wallstents). METHODS: Diameter- and length-matched PET stents and Wallstents were symmetrically implanted in the paired iliac arteries of 13 crossbred domestic swine. Stent deployment was studied angiographically and with intravascular ultrasound immediately after stent implantation. The angiographic stented lumen diameter was measured using quantitative vessel analysis before, immediately after stenting, and at 6-week follow-up. Cross-section histopathology and area morphometry were performed. RESULTS: Immediately poststenting, intravascular ultrasound revealed proximal dislocation of 5 of the 13 PET stents, whereas all metal stents were firmly embedded at the implantation site. At 6-week follow-up, three of the remaining PET stents were totally or subtotally occluded by organized thrombus, whereas all metal stents were patent. Compared with immediately poststenting, the angiographic lumen diameter within the five remaining PET stents was reduced by 30%, and that of the metallic stents was virtually unaltered (p < 0.02). This observation was confirmed by postmortem morphometry, wherein the PET-stented vessel segments a diameter stenosis of 40% was measured vs only 9% in the metallic stents (p < 0.0001). CONCLUSION: PET-stent deployment is difficult to control due to the lack of radiopacity of this stent. PET stents seem to be more thrombogenic and lead to significantly more neointimal proliferation than metallic stents.

Animals↗