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Biomedical subjects

D M Braile

Publications and source records attributed to D M Braile.

At least 19 recordsLinked to original sources
PubMed1998

The chemical protecting group concept applied in crosslinking of natural tissues with glutaraldehyde acetals.

This work describes the results of the controlled crosslinking of collagen matrices by glutaraldehyde based on a double protection strategy, glutaraldehyde acetals and lysine protonation due to the acidic conditions of acetal formation. Materials crosslinked by this approach were characterized by thermal stability comparable to those obtained by conventional procedures with mechanical properties expected for bioprosthesis manufacture and with a higher stability toward collagenase hydrolysis. The integrity of the microfibrillar structure was confirmed by optical and scanning electronic microscopy. The results indicate that the glutaraldehyde acetals procedure may be of potential use for the crosslinking of bovine pericardium used in the manufacture of bioprosthetic devices. Advantages may be related to the production of materials with homogeneous crosslinking distributions, associated with better definition in the nature of the chemical link that they introduce, due to a better distribution of glutaraldehyde within the tissue matrix before the crosslinking reaction is allowed to occur. As a result, materials with improved biological and mechanical properties are expected.

Acetals↗
PubMed1998

[Left atrial myxoma and isquemic stroke in a child].

The authors present a case of left atrial myxoma with stroke in an 8-year-old female child. The tumor was removed and two months after the surgery a left atrial septum mass was observed suggesting recurrence. The child was asymptomatic. Literature review emphasizes the rarity and clinically aggressive behavior of this tumor at this age group and demonstrates rare recurrence rates after surgery.

Brain Ischemia↗
PubMed1998

Mapping of bovine pericardium: physical and histopathologic tests.

BACKGROUND AND AIMS OF THE STUDY: This study was performed to identify the physical and histopathologic characteristics of different sections of glutaraldehyde-tanned bovine pericardium. METHODS: Ten pericardial sacs were obtained from animals aged from 18 to 36 months. Physical tests included shrinkage and mechanical resistance (rupture, elongation, tenacity index). Collagen and elastic fibers were evaluated in Gomori's trichrome-stained sections, hematoxylin and eosin, by PAS and Verhoeff's method. Studied areas were proximal to the great arteries, and the right atrial, right ventricular, left ventricular and left atrial regions. RESULTS AND CONCLUSIONS: Results showed that bovine pericardium does not have enough regional differences to identify any single region for bioprosthesis manufacture. However, histopathology showed better preservation of collagen and elastic fibers in the right ventricular region, implying that this area is more adequate as bioprosthetic material.

Animals↗
PubMed1998

[High output heart failure due to coronary fistula].

A 45 year-old woman complaining of heart failure symptoms (New York Heart Association--class III) and a non typical thoracic pain was submitted to a transthoracic echocardiogram which showed a very dilated coronary artery and a fistula to the right atrium. The angiograms confirmed the same findings. She underwent open heart surgery which confirmed the diagnosis. Fistula ligation was then undertaken. She remains symptom-free three years after the operation.

Arteriovenous Fistula↗
PubMed1997

[Use of a thin retrocardiac drain after open heart surgery. Description of the technique].

PURPOSE: To describe a technique with a thin drainage system placed behind the heart, avoiding reoperation caused by tamponade due to pericardial effusion in patients who undergo open heart surgery. METHODS: We studied 59 patients, average age of 50 years. Twenty-six (44%) patients had undergone CABG, 25 (42%) valvar procedures and 8 (14%) different procedures. The control group were 20 patients, average age 44 years. Nine (45%) underwent CABG, 6 (30%) valvar procedures and 5 (25%) other procedures. Every patient was submitted to echocardiographic study to verify presence of pericardial effusion after operation. RESULTS: There was one patient with pericardial effusion with 8mm in the study group. Six patients showed pericardial effusion in the control group. The control group had mean drainage flow of 320 +/- 110ml and average permanence time was 45 +/- 10h. The study group had mean drainage flow of 410 +/- 122ml, the average permanence time was 46 +/- 10h. There was statistic difference between both groups when we compared the frequency of pericardial effusion. CONCLUSION: This drainage system reduces pericardial effusion comparing with the literature and causes little discomfort to the patient. The fixed rule to remove the drains did not present more discomfort to the patient and there were no complications related to its permanence.

Adult↗
PubMed1996

Dynamic cardiomyoplasty in South America.

BACKGROUND: Dynamic cardiomyoplasty has been proposed in the treatment of severe cardiomyopathies. However, few reports to date have shown significant numbers of patients collected on a multicenter basis. METHODS: From July 1987 to June 1994, dynamic cardiomyoplasty was performed in 112 patients in South America. The indications were dilated cardiomyopathy in 96 patients, Chagas' disease cardiomyopathy in 13, and ischemic cardiomyopathy in 3. Left latissimus dorsi muscle was used in all patients. RESULTS: The thirty-day mortality rate was 8.1%, and patients were followed up for 22.1 +/- 18.6 months. Data of surviving patients show that 47.3% were in New York Heart Association functional class I, 45.6% in class II, and 7% in class III or IV 1 year after the operation. The 1-year survival was 78.4%; 2-year, 59.7%; and 5-year, 41.7%. The survival at 1 year was 86.1% for patients with dilated cardiomyopathy and 40% for those with Chagas' disease. At 5 years, these values were 49.8% and 9.5%, respectively. Long-term survival was also significantly affected by preoperative functional class and pulmonary vascular resistance. However, patients operated on in class III or intermittent class IV and without elevated pulmonary vascular resistance had survival rates of 91.5% at 1 year and 76.7% at 5 years of follow-up. CONCLUSIONS: Cardiomyoplasty improves the functional status of patients with severe cardiomyopathies. Otherwise, long-term survival after this procedure is limited in patients with Chagas' disease and by patients' condition before the operation.

Adult↗
PubMed1996

-Rate-responsive pacemaker with an unexpected chronotropic response-.

The pacemaker with rate-responsiveness was a great advance in cardiac stimulation, however, the choice of the best biosensor is still object of research. A 35 year-old woman with a responsive pacemaker implanted due to a complete heart block after interventricular septal defect surgical correction was admitted. The pacemaker showed improper cronothropic response with high frequency due to biosensing malfunction. Malfunction related to muscle stimulation in the generator pocket and a high response rate. A palliative procedure was made until the end of pregnancy, by reducing the sensitivity of biosensing.

Adult↗
PubMed1994

Pathologic findings in 74 dysfunctional Braile-Biomédica bovine pericardial heart valves recovered at reoperation, 1978 to 1990.

This report describes the morphological data obtained from 74 Braile-Biomédica bovine pericardial valves (previously named IMC bovine pericardial valve) recovered at reoperation in our institution between 1978 and 1990. This retrospective analysis allowed for a thorough evaluation of the pathologic findings after long-term implantation of the Braile-Biomédica pericardial xenograft. The major cause of valve failure was pericardial tissue calcification, causing cuspal stiffening or structural defect responsible for clinical symptoms of stenosis and/or regurgitation. Our results demonstrated calcification in 65% of the explanted bioprostheses. Calcific deposits were most extensive in the tunica fibrosa of the pericardium, more prevalent in patients less than 30 years old at the time of implantation, and in valves implanted in the mitral position. Mild to moderate degenerative changes of the native pericardium were observed. No differences between men and women could be detected. Endocarditis was the second most frequent cause of xenograft failure (16%). Cuspal tears, contrasting with previous reports on the pathological features in clinically failed pericardial valves, were relatively infrequent (6.8%). Two valves explanted (2.7%) because clinical manifestation of valvular incompetence showed marked degenerative changes of the pericardial native tissue as the only findings. These observations, very similar to those reported for porcine aortic valves, complement and give support to previously published data on the satisfactory clinical performance of the Braile-Biomédica pericardial bioprosthesis. The discrepancy between the present observations and those reported by other authors on different types of pericardial valves, reinforces the opinion that these pericardial bioprostheses should not be studied as an unified group, the results and conclusions must be specific for each one of them.

Adolescent↗
PubMed1992

[The PB IMC bovine pericardial prosthesis: 11 years in the mitral position. Instituto de Moléstias Cardiovasculares].

PURPOSE: To evaluate the postoperative results of patients with valvular bovine pericardium prosthesis in mitral position. METHODS: From 1977 to 1988, 10.812 bovine pericardial valves were produced by IMC Biomédica and implanted. Our group at IMC implanted 1,193. Of the 663 patients with mitral change, 586 were adults and 77 were youngsters (under 21). The rheumatic fever was the most frequent primary cause of valvar disease (76.5%). The stenosis (23.0%) and the insufficiency (20.7%) were the most common of the damages that led to mitral exchange. We studied 602 patients that left the hospital, representing 666 bioprostheses in 11 years. The surgeries were performed with standard cardiopulmonary bypass with crystalloid cardioplegia in the first seven years and hypothermic or normothermic blood cardioplegia enriched with amino acids in the last four years. RESULTS: Hospital mortality was 9.2%; 13.2% for the first 5.5 years (group I) and 6.3% for the last 5.5 years (group II). Eleven-year follow-up was 98.8% and the mean time was 3.8 years. The actuarial study showed a survival rate of 74.3 +/- 6.5% for the youngsters and 73.0 +/- 3.7% for the adults, with 95.0 +/- 1.0% of the patients free from valve-related fatal complications corresponding to one event % patient-years (endocarditis 0.6%; calcification 0.1%; thromboembolism 0.3%). The actuarial rate of non fatal valve-related late complications was 55.2 +/- 8.6% of patients free from all complications, corresponding an incidence of 2.9%/patient-year (endocarditis 0.5%; calcification 1.8%; thromboembolism 0.3%; periprosthetic leakage 0.2% and rupture 0.08%). In this period 95.8 +/- 1.6% of the patients were free from thromboembolism; 99.1 +/- 0.6% free from rupture; 90.1 +/- 4.08% free from endocarditis in the young group (1.5%/patient-year) and 95.2 +/- 1.03% for adults (1.0%/patient-year). For calcification, the actuarial rate was 43.1 +/- 12.3% for youngsters (7.5/patient-year) and 68.8 +/- 9.3% for adults (1.1%/patient-year). CONCLUSION: IMC pericardial bioprosthesis performed well in a period of 11 years with low rates of fatal complications; ruptures and thromboembolism without the use of anticoagulants. Calcification was the major complication mainly in youngsters.

Adolescent↗
PubMed1992

[The functional expectations of valve bioprostheses. I. Physical and histopathological tests for the use of sections of bovine pericardium].

PURPOSE: The heterogenicity of the bovine pericardium sac regarding its elasticity, extensibility and thickness encouraged the work with the purpose to study the different areas of pericardium, mapped according to its position on the heart. METHOD: Ten bovine pericardium sacs previously selected and obtained at the slaughterhouse immediately after the animal slaughter were utilized. The pericardia were sectioned sagittally from the anterior to the posterior portion, thus obtaining two parts, right and left. Two areas were demarcated for each one of them amounting to four regions: A, B, C and D. Each of the four regions was divided into two regions: 1 and 1, amounting to 80 samples. There have been physical tests (shrinkage and mechanical resistance), histopathological studies and statistical analysis were done. RESULTS: The right ventricle area (region D) had the best utilization (21.3%), and then the left ventricle area (region B, 16.2%). The physical tests on the utilized samples showed minimum and maximum values of 0.20 and 0.40 mm for the thickness, 2.0 and 7.0 kgf for force, 1.6 and 4.2 kgf/mm2 for rupture, 18 and 36% for stretching, 15 and 65 for tenacity index and 85 and 87 degrees C for shrinkage. The region D presented histologically and more preserved, either for the collagen fibers or the elastic ones. CONCLUSION: The results of the statistical analysis proved the need to increase the sample size to certify the existence of a sectioning of the pericardium and a more adequate position of the proof body (longitudinal, transversal and oblique) when obtaining the pericardium flap to make the valve bioprosthesis.

Animals↗
PubMed1992

[Transluminal coronary angioplasty combined with cardiomyoplasty in the treatment of coronary disease associated with dilated cardiomyopathy].

A 53-year-old white female candidate to cardiomyoplasty to control heart failure class III (NYHA). Submitted to coronary angioplasty, presented at the coronarography 75% obstruction of the left anterior descending (LAD) artery and at the left ventriculography diffuse and severe hypocontractility ejection fraction (EF) = 17%. After primary success of the coronary dilatation, she was operated on with a good surgical outcome. Six months after the surgery, she did well clinically (class II) and at the coronarography the LAD artery presented free from restenosis or progression of the disease and the left ventriculography showed improvement of the ventricular function (EF = 28%).

Angioplasty, Balloon, Coronary↗