2-(amino)oleic-acid and Heart-Valve-Diseases

Durability remains the main problem of all bioprosthetic valves, and calcification is the major cause of failure. New tissue treatment processes are expected to reduce mineralization. A comparative animal study was undertaken to evaluate the behavior of a new-generation porcine bioprosthesis in contrast with a first-generation porcine bioprosthesis. The primary goal was to evaluate the efficacy of alpha-amino-oleic acid as an anticalcification treatment.. Seventeen Targhee sheep (aged 4.5-7 months) had a mitral valve replacement with a Mosaic or Hancock Standard. The animals were followed up to 20 weeks (144.1 +/- 4.0 days vs 144.3 +/- 8.2 days) and then euthanized as scheduled. After gross examination, the explants were radiographed for the presence of calcification. The central portions were preserved for histologic examination, and the remainder of the sample was analyzed for quantitative calcium content by atomic absorption spectroscopy.. Four Mosaic sheep were excluded because of perioperative surgical mortality. The remaining 13 were enrolled in the study (9 Mosaic and 4 Hancock Standard). The mean calcium content was 1.97 +/- 2.21 microg/mg tissue weight for Mosaic versus 8.36 +/- 4.12 microg/mg for Hancock Standard valves (P < .01). Mild fibrous tissue overgrowth and fibrinous lining were observed regardless the xenograft type.. The low level of calcification in the Mosaic versus Hancock Standard xenografts confirms the efficacy of alpha-amino-oleic acid treatment in mitigating mineralization. A longer durability is expected with the clinical use of the Mosaic porcine valve.

Topics: Animals; Bioprosthesis; Calcinosis; Cardiovascular Agents; Disease Models, Animal; Heart Valve Diseases; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Mitral Valve; Models, Cardiovascular; Oleic Acid; Oleic Acids; Sheep

New anticalcification treatments for stentless bioprostheses have not yet been compared independently.. The No-reacts (Biocor), AOA (Medtronic Freestyle), and BiLinx (SJM Toronto SPV II) methods were studied and compared with a control group. Aortic valve leaflet and aortic root tissue was subcutaneously implanted in 60 male, 21-days-old Sprague-Dawley rats. Calcium content was quantified using inductively coupled plasma spectrophotometry.. No infections occurred. Low levels of calcium were measured in aortic valve leaflet tissue for all methods (0.4 to 1.5 mg/g dry weight) in comparison to the control group (225 mg/g), p < 0.01. Calcification of aortic root tissue was low in the Bilinx group (2.4 mg/g, p < 0.01), whereas calcium levels were high in all other groups (104 to 127 mg/g).. Calcification of aortic valve leaflets was significantly reduced by all new anticalcification treatments, whereas aortic root calcification was only reduced by inhibition of cellular calcification (BiLinx). Maximum anticalcification properties of both leaflet and aortic root are important, as these are considered a functional unit in stentless bioprostheses.

Topics: Aluminum Chloride; Aluminum Compounds; Animals; Aorta, Thoracic; Aortic Diseases; Aortic Valve; Astringents; Bioprosthesis; Calcinosis; Calcium; Chlorides; Coated Materials, Biocompatible; Disease Models, Animal; Drug Combinations; Ethanol; Fixatives; Follow-Up Studies; Glutaral; Heart Valve Diseases; Heart Valve Prosthesis; Male; Oleic Acids; Prosthesis Design; Rats; Rats, Sprague-Dawley; Solvents; Stainless Steel; Surface-Active Agents

We examined 67 explanted Medtronic Freestyle (MF) valves of 0 to 1,490 days of implantation from 66 patients, including 9 full-root, 17 root inclusion, and 41 subcoronary implants derived from a multicenter trial composed of 1,100 patients at 27 centers worldwide (58 valves) and other removed specimens (9 valves). Macroscopic, radiographic and histological examination was performed to establish clinicopathological correlations in retrieved MF stentless aortic bioprostheses. Indications for 30 explants obtained at reoperation were perioperative technical (1 bleeding, 3 iatrogenic valve damage), endocarditis (11), sterile perivalvular leak (4), valve stenosis (1) regurgitation (3), fistula (2), or degeneration (2 cuspal tears, 1 cusp separation). Autopsy specimens were obtained after valve-related (9), non-valve-related (22), or perioperative death (6). Most non-valve-related deaths were cardiac. Valve-related deaths included endocarditis (4), paravalvular leak (1), thrombus (2), subannular occlusion (1), and tamponade (1). No excessive pannus was present. Macroscopic valve thrombosis was noted in two subcoronary implants of 180 and 279 days' duration. Histological analysis on all valves of more than 10 days implant duration or with macroscopic abnormality revealed variable but progressive flattening of the valve cusps; focal, plaquelike unorganized mural thrombus; cuspal fluid insudation; and generalized, nonspecific degenerative changes typical of explanted porcine valves. Aortic wall calcification was seen in two explants of 47 and 49 months' duration, the later with associated cuspal tear. Cusp mineralization was limited to infected valves. No excessive inflammation or fibrosis at the host-device interface was noted. Pathological findings were generally similar to those seen in clinically used glutaraldehyde-fixed xenografts. Potential pathology related to stentless design including pannus, aortic wall calcification, and host-tissue interaction were not clinically significant. Nevertheless, examination of many explanted valves at extended intervals and ongoing clinical data are needed to confirm the long-term efficacy, safety, and characteristic modes of failure of stentless bioprostheses.

Topics: Adult; Aged; Aged, 80 and over; Aorta, Thoracic; Aortic Valve; Bioprosthesis; Female; Heart Valve Diseases; Heart Valve Prosthesis; Humans; Male; Middle Aged; Oleic Acids; Postoperative Complications; Prosthesis Design