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Clinical Infectious Diseases : An... Jun 1998
Topics: Endocarditis, Bacterial; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Prosthesis-Related Infections
PubMed: 9636853
DOI: 10.1086/516377 -
Journal of Cardiac Surgery 2007
Topics: Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Thrombectomy; Thrombosis
PubMed: 17488418
DOI: 10.1111/j.1540-8191.2007.00389.x -
The Canadian Journal of Cardiology Jul 2021Surgical replacement remains the primary option to treat the rapidly growing number of patients with severe valvular heart disease. Although current valve... (Review)
Review
Surgical replacement remains the primary option to treat the rapidly growing number of patients with severe valvular heart disease. Although current valve replacements-mechanical, bioprosthetic, and cryopreserved homograft valves-enhance survival and quality of life for many patients, the ideal prosthetic heart valve that is abundantly available, immunocompatible, and capable of growth, self-repair, and life-long performance has yet to be developed. These features are essential for pediatric patients with congenital defects, children and young adult patients with rheumatic fever, and active adult patients with valve disease. Heart valve tissue engineering promises to address these needs by providing living valve replacements that function similarly to their native counterparts. This is best evidenced by the long-term clinical success of decellularised pulmonary and aortic homografts, but the supply of homografts cannot meet the demand for replacement valves. A more abundant and consistent source of replacement valves may come from cellularised valves grown in vitro or acellular off-the-shelf biomaterial/tissue constructs that recellularise in situ, but neither tissue engineering approach has yet achieved long-term success in preclinical testing. Beyond the technical challenges, heart valve tissue engineering faces logistical, economic, and regulatory challenges. In this review, we summarise recent progress in heart valve tissue engineering, highlight important outcomes from preclinical and clinical testing, and discuss challenges and future directions toward clinical translation.
Topics: Biocompatible Materials; Heart Valve Diseases; Heart Valve Prosthesis; Humans; Long Term Adverse Effects; Materials Testing; Tissue Engineering; Translational Research, Biomedical
PubMed: 33839245
DOI: 10.1016/j.cjca.2021.03.022 -
Canadian Association of Radiologists... Sep 1988Clinical signs of heart valve malfunction are often not specific so that recognition frequently depends on nonclinical methods. The chest radiographs of 34 patients with... (Comparative Study)
Comparative Study
Clinical signs of heart valve malfunction are often not specific so that recognition frequently depends on nonclinical methods. The chest radiographs of 34 patients with 41 prosthetic valve malfunctions (PVM) were compared before and after valve failure. The most frequent sign of PVM is postcapillary hypertension (90%). A marked increase in heart size occurs with regurgitation but not with obstruction. A change in attitude of a valve of more than 6 degrees. in the aortic and 12 degrees in the mitral position is virtually diagnostic of dehiscence. This was seen in 52% of patients with paravalvular regurgitation and in 29% of all patients with PVM. When dehiscence is suspected on clinical or radiologic grounds the valve should be examined fluoroscopically. Changes in the azygos vein and the vascular pedicle of the heart and the development of pleural effusions are less useful signs of PVM. Although the chest radiograph is often not diagnostic of PVM, it may point to the need for definitive investigation.
Topics: Adult; Aortic Valve; Female; Heart Valve Prosthesis; Humans; Male; Mitral Valve; Prosthesis Failure; Radiography, Thoracic; Tricuspid Valve
PubMed: 2971051
DOI: No ID Found -
Radiographics : a Review Publication of... 2012Prosthetic heart valves (PHVs) are commonly implanted to replace diseased native heart valves. PHV dysfunction is an infrequent but potentially life-threatening...
Prosthetic heart valves (PHVs) are commonly implanted to replace diseased native heart valves. PHV dysfunction is an infrequent but potentially life-threatening condition. In daily clinical practice, transthoracic and transesophageal echocardiography and fluoroscopy are the imaging modalities used for diagnostic evaluation of suspected PHV dysfunction. These modalities may not allow determination of the cause of PHV dysfunction, mostly because of acoustic shadowing. Multidetector computed tomographic (CT) angiography is a promising complementary technique for evaluation of PHVs, especially in patients with PHV obstruction and endocarditis. The CT image quality of PHVs mainly depends on their composition, with most causing only limited artifacts. Retrospectively electrocardiographically gated acquisition is advisable for PHV imaging because it enables dynamic leaflet evaluation and anatomic assessment in both systole and diastole. For accurate image interpretation, dedicated reconstruction in plane with and perpendicular to the PHV leaflets is mandatory. Besides PHV assessment, CT also provides information on the coronary arteries, the location and patency of bypass grafts, the dimensions of the aorta, and the distance between the sternum and right ventricle, information valuable for planning repeat surgery. To achieve the optimal diagnostic yield in PHV imaging, multidisciplinary cooperation between the departments of cardiology, cardiothoracic surgery, and radiology is crucial.
Topics: Coronary Angiography; Heart Valve Diseases; Heart Valve Prosthesis; Humans; Prosthesis Failure; Radiographic Image Enhancement; Tomography, X-Ray Computed
PubMed: 23150847
DOI: 10.1148/rg.327125702 -
Journal of Cardiac Surgery Jun 1989
Topics: Heart Valve Prosthesis; Humans; Liability, Legal; Malpractice; Medical Laboratory Science; United States
PubMed: 2519989
DOI: 10.1111/j.1540-8191.1989.tb00265.x -
The Thoracic and Cardiovascular Surgeon Feb 1986From 1974 to 1984, 847 heart valve replacement operations were performed with 1005 prosthetic valves. Thirty-nine (4.6%) were reoperations with 43 prosthetic valve...
From 1974 to 1984, 847 heart valve replacement operations were performed with 1005 prosthetic valves. Thirty-nine (4.6%) were reoperations with 43 prosthetic valve replacements (PVR), on 38 patients. Thirty-three patients had received their initial valve replacement in our hospital and 5 elsewhere. Twenty additional cardiac procedures were required, concomitantly with the prosthesis replacement. Twenty-three patients underwent replacement of a mechanical prosthesis (61%) an average of 4.3 years after initial implantation and 15 patients a bioprosthesis (39%) after 2.8 years. Indications for PVR were endocarditis in 15 patients (39%), prosthesis failure in 13 (34%), periprosthetic leak in 7 (18%), thrombosis in 2 (5%), and a left ventricle subannular aneurysm in 1 (3%). Preoperatively 4 patients were in NYHA functional class II (11%), 15 in class III (39%) and 19 in class IV (50%). Six patients died early postoperatively (15.8%) Various risk factors were analyzed. The early mortality rate was 22% for mechanical prosthesis replacement and 7% for bioprosthesis; 11% for aortic position, 13% for mitral position and 50% to 100% for double valve replacement; 23% for non-elective and 6% for elective operations; 10% for patients with only an initial valve replacement and 43% with additional previous valve operations; 18% for active endocarditis, 15% for prosthesis failure, 14% for periprosthetic leak, 0% for thrombosis and 100% for subannular aneurysm; 0% for patients in class II, 7% in class III and 26% in class IV; 6% in patients with an aortic cross-clamp time less than 2 hours and 24% with more; 27% prior to 1981 and 9% during the last 4 years; and finally 50% in patients over the age of 60.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Adolescent; Adult; Aged; Aortic Valve; Bioprosthesis; Endocarditis; Female; Heart Valve Prosthesis; Humans; Male; Middle Aged; Mitral Valve; Postoperative Complications; Prosthesis Failure; Reoperation; Risk; Tricuspid Valve
PubMed: 2421440
DOI: 10.1055/s-2007-1020364 -
Journal of Biomechanics 1986The diameter of prosthetic heart valves is usually chosen according to the anatomic annulus size as determined during open-heart surgery. Therefore, this approach does...
The diameter of prosthetic heart valves is usually chosen according to the anatomic annulus size as determined during open-heart surgery. Therefore, this approach does not take into account the dimensional changes induced by heart pathology and surgical procedures. In addition, current practice fails to consider the variations of heart dimensions due to hemodynamic improvement following valve replacement. Here we suggest a method to determine the appropriate prosthesis diameter according to the hemodynamic features of the patient, to its kind of activity, and to the type of prosthesis. Assuming that the pressure drop across a valve can be calculated as delta p = apv 2/2, and considering the variation of blood flow with time and its change induced by frequency, it is possible to obtain the relationship between pressure drop and prosthetic valve diameter. The results obtained with this analytical method have been plotted on diagrams which allow the graphical determination of the proper valve diameter.
Topics: Aortic Valve; Biomechanical Phenomena; Heart Valve Prosthesis; Hemodynamics; Humans; Mathematics; Mitral Valve; Models, Cardiovascular; Prosthesis Design; Rheology
PubMed: 3949817
DOI: 10.1016/0021-9290(86)90110-7 -
Texas Heart Institute Journal 1996
Review
Topics: Anticoagulants; Biocompatible Materials; Endothelium, Vascular; Heart Valve Prosthesis; History, 20th Century; Humans; Prosthesis Design; Thromboembolism
PubMed: 8680270
DOI: No ID Found -
The Thoracic and Cardiovascular Surgeon Oct 1985The Omniscience prosthetic heart valve has been clinically evaluated in 44 patients operated on between January and July, 1981. There were 23 aortic valve replacements...
The Omniscience prosthetic heart valve has been clinically evaluated in 44 patients operated on between January and July, 1981. There were 23 aortic valve replacements (AVR), 18 mitral valve replacements (MVR) and 3 double valve replacements (DVR). Mean age was 48 +/- 11 years. Preoperatively, 61% patients were in New York Heart Association (NYHA) functional class IV, 36% in class III and 2% in class II. The hospital mortality rate was 4.5%. Actuarial freedom from thromboembolic events was 97.4 +/- 2.6% (3 1/2 years of follow-up). Postoperatively, 93% of the patients were in NYHA class I and 7% in class II. There were 7 cases of periprosthetic leak requiring reoperation (6 AVR, 1 MVR) for an overall incidence of 6.3% per patient year. In all these cases the causative factor was considered to be the Dacron sewing ring. All patients survived the reoperation. The actuarial survival rate was 93.9 +/- 5.9% for AVR and 93.7 +/- 6.1% for MVR. These data would suggest that the Omniscience prosthesis represents an acceptable device for heart valve replacement, except for the high incidence of periprosthetic leakage, related to the Dacron sewing ring. Recent modification of the valve-construction including a Teflon sewing ring may avoid the relatively high rates of periprosthetic leakage following implantation of this mechanical valve.
Topics: Acenocoumarol; Adult; Aged; Anticoagulants; Cardiovascular Diseases; Equipment Design; Equipment Failure; Evaluation Studies as Topic; Female; Heart Valve Prosthesis; Humans; Male; Middle Aged; Postoperative Complications; Reoperation; Thromboembolism
PubMed: 2416084
DOI: 10.1055/s-2007-1014144