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Prosthesis-related complications: first-year annual rates.

The rates of valve-related complications determine the clinical performance of biological and mechanical heart valve prostheses by valve position. The crude rates of valve-related complications within the first year after implantation have not been previously reported. The Food and Drug Administration (FDA) of the United States guidance document for the performance of new heart valve prostheses uses objective performance criteria (OPC) as target values for valve-related complications. The FDA requirement for each valve-related complication is that the rate cannot be greater than twice the OPC. This report provides the first-year rates of valve-related complications from a university database of over 7,000 implants, followed longitudinally between 1982 and 1999, of currently marketed biological and mechanical heart valve prostheses. The aim of this report was to provide an additional method for consideration by regulatory authorities in determination of the standards of performance for pre-market approval of new prosthetic valves for heart valve replacement surgery.

Aortic Valve↗

Percutaneous transvenous mitral commissurotomy in a patient with prosthetic aortic valve.

Patients with rheumatic valvular heart disease who have undergone valve surgery may present later with progression of disease in other valves. We report a case of successful percutaneous transvenous mitral commissurotomy (PTMC) in a 58-year-old male who underwent aortic valve replacement (AVR) with a No. 23 Björk-Shiley valve for severe rheumatic aortic regurgitation in 1982. At AVR, echocardiography revealed mild mitral stenosis (MS) and mitral valve area (MVA) 2.5 cm2. Over 18 years, the mitral valve disease progressed to severe MS and the patient presented with class III exertional dyspnea. He underwent successful PTMC (Inoue balloon technique). Post-procedure echocardiography revealed a MVA of 2.0cm2 and grade II mitral regurgitation. Anticoagulation management, infective endocarditis prophylaxis and procedural modifications are discussed.

Aortic Valve Insufficiency↗

[Infectious endocarditis caused by Leuconostoc mesenteroides].

BACKGROUND: Leuconostoc spp. are gram-positive coccobacilli, catalase and oxidase negative, vancomycin resistant, with a not clearly defined role in human infectious. Cases of infection have been reported previously but it has not been described confirmed infective endocarditis due to Leuconostoc mesenteroides. METHODS: We describe a case of prosthetic valve endocarditis in a 72-years-old woman with a long previous history of cardiac disease but without other immunological disorders. She developed a heart failure because of prosthetic aortic valve dysfunction. CONCLUSIONS: Leuconostoc mesenteroides should be considered as a potential cause of infective endocarditis and listed in the group of vancomycin-resistant microorganism.

Aged↗

[Mechanical mitral valve prosthesis dysfunction in pregnant women. Report of 2 cases].

We present two cases of pregnant women associated with mechanical mitral valve prostheses dysfunction, treated between October 1998 and September 2000, in congestive heart failure, functional class III, without fetal distress. Emergency surgery consisted in cesarean procedure immediately followed for mitral prostheses removal and implantation of new mechanical heart valve prostheses was realized in both patients. In each case a single live infant was obtained with good Apgar evaluation. Both patients had successful surgical procedures. In both patients were found thrombi in the mechanical heart valves. Actually patients and their children have good evolution, without any problem.

Adult↗

Five-year follow up of the ATS mechanical heart valve.

BACKGROUND AND AIM OF THE STUDY: Between January 1, 1997 and December 31, 2001, a total of 342 patients underwent aortic valve replacement (AVR) or mitral valve replacement (MVR) with the ATS Medical prosthesis. The initial three-year phase of this study took place under a United States Food and Drug Administration-approved investigational device exemption study. The study aim was to determine the incidence of valve-related events in up to five years of follow up after valve implantation, and to assess patient disturbance from valve noise. METHODS: Patients were consecutively enrolled to undergo AVR or MVR with the ATS prosthesis. Follow up studies were conducted by patient questionnaire and/or telephone call. Follow up was 96% complete. AVR was conducted in 246 patients (80 with coronary bypass), and MVR in 96 patients (29 with coronary bypass). RESULTS: The overall operative mortality was 2.6% (n = 9; AVR 3.2%, n = 8; MVR 1.0%, n = 1), with two deaths being valve-related (0.6%). In 878 patient-years (pt-yr) of follow up (613 pt-yr for AVR; 265 pt-yr for MVR) there were an additional 22 deaths. Five deaths (0.6%/pt-yr) were valve-related: two were neuroembolic (both MVR), one from endocarditis (AVR), and two from bleeding events (both AVR). Late valve-related complications (>30 days) included 17 episodes of major bleeding (11 AVR, 1.8%/pt-yr; six MVR, 2.3%/pt-yr), five permanent neuroembolic events (four AVR, 0.7%/pt-yr; one MVR, 0.4%/pt-yr); 16 transient neuroembolic events (10 AVR, 1.6%/pt-yr; six MVR, 2.3%/pt-yr); three transient peripheral emboli (two AVR, 0.3%/pt-yr; one MVR, 0.4%/pt-yr); four paravalvular leaks (two AVR, 0.3%/pt-yr; two MVR, 0.8%/pt-yr); and one episode of valve thrombosis (MVR, 0.4%/pt-yr; AVR, 0%/pt-yr). Reoperation was required in two patients: one AVR (paravalvular leak, 0.2%/pt-yr) and one MVR (replacement due to thrombosis, 0.4%/pt-yr). CONCLUSION: These results indicate that intermediate-term results with the ATS mechanical prosthesis continue to be excellent, though further long-term follow up is warranted.

Adult↗

Comparative assessment of hepatic Glisson's capsule and bovine pericardium in heart valve bioprostheses.

BACKGROUND AND AIM OF THE STUDY: The optimal material for heart valve bioprostheses remains disputable. This investigation was initiated to compare the properties of hepatic Glisson's capsule, clinical experience of which in cardiovascular surgery is minimal, with those of bovine pericardium. METHODS: Hepatic Glisson's capsule was harvested from bull calves and used to create composite pulmonary arterial monocusp grafts and bioprostheses. Comparison of the strength and elastic properties of Glisson's capsule and bovine pericardium, as well as the hydrodynamic characteristics of valves made from these materials, was performed. Late results of operations using these materials were estimated echocardiographically. RESULTS: Although Glisson's capsule tissue is thinner than the bovine pericardium, its elasticity modulus is greater. However, the hydrodynamic characteristics of heart valves made from either tissue are similar. Moreover, valves made from Glisson's capsule have a lower systolic pressure gradient on the prosthesis and a higher effective orifice area. Composite pulmonary arterial xenopericardial grafts with a monocusp of Glisson's capsule were used in 30 patients during tetralogy of Fallot repair. Glisson's capsule was also used for tricuspid valve reconstruction and as a bioprosthesis in six patients with Ebstein's anomaly. At 1-2 years after surgery, the Glisson's capsule tissue remained thin and flexible, with no calcification. CONCLUSIONS: Although the hydrodynamic properties of hepatic Glisson's capsule and the bovine pericardium are similar, the capsule tissue is thinner and has a greater elasticity modulos. Thus, Glisson's capsule may be used for bioprosthesis construction both independently and in combination with bovine pericardium.

Animals↗

Percutaneous transcatheter repair for mitral regurgitation.

Percutaneous mitral valve repair for patients with mitral regurgitation is emerging as an exciting new area in interventional cardiology. Because of the complex etiologies of mitral regurgitation, multiple technologies are being tested in preclinical and clinical settings to evaluate their efficacy and safety. Direct percutaneous repair of the mitral valve is undergoing Phase II and Phase I trials using the Evalve mitral clip and Edwards mitral suture devices, respectively. Devices placed in the coronary sinus might be applicable for specific patient populations where the mitral annulus and coronary sinus have favorable anatomic relationships. Other devices employ intra-atrial or intra-ventricular approaches to the mitral annulus to move the posterior annulus forward and thereby improve mitral valve coaptation. How many of these new techniques will ultimately be successful for clinical use will depend on the results of ongoing clinical trials.

Cardiac Surgical Procedures↗

[Reoperations on prosthetic heart valves: an analysis of 64 cases].

During the period of Fabruary 1988 to May 1996, 64 reoperations were performed for prosthetic valve malfunction. Degeneration of bioprosthesis occurred in 46 patients, failure of mechanical prosthesis in 9, and periprosthetic leakage without evidence of infection in 9. In accordance with the status of cardiac function, 9 patients with acute dysfunction of mechanical prosthesis received emergency operations, and the remaining 55 patients with bioprosthetic valve failure or periprosthetic leakage received selective operation. There were 8 early deaths with a overall hsopital mortality rate of 12.5%. Three of the deaths occurred among the 55 selective procedures for a mortality of 5.3% and 3 of the deaths occurred among the 9 emergence procedures for mortality of 33.3%. The 56 long-term survivors were followed up from 3 months to 7 years (mean 2.1 years). There were 3 late deaths (5.3%). Forty-eight patients have been living more than 1 year. Their cardiac function after reoperation was class I (42 patients), class II (5), and class III (1). The timing of reoperation and surgical technique were discussed.

Adult↗

[Widening plasty of the anterior cusp in rheumatic mitral insufficiency].

UNLABELLED: The mechanism of insufficiency in rheumatic valve disease includes 1. annulus dilatation and 2. restricted leaflet motion. Aiming at improving the treatment of restriction, augmentation of the anterior mitral leaflet (AML) was achieved with a piece of autologous pericardium. METHODS: between January 1995 and December 1999, out of 274 patients refered for rheumatic mitral disease, 143 patients underwent a repair (52%), 81% of them had pure regurgitation with no stenosis. Ring annuloplasty was performed in all cases. Two techniques used for treating the restrictive componant of the regurgitation were compared in two consecutive cohort of patients: no AML augmentation (n=62) and AML augmentation (n=81). Mean age was 42 + 3 years and all preoperative variables were comparable except for the incidence of redo patients who all underwent AML extension. RESULTS: in hospital mortality was 0.7% (n=1 with AML extension) and there was one early reoperation for a pericardial patch dehiscence. After a mean follow-up of 3.2 years, there was one sudden death (no AML extension). The reoperation rate was lower with (2.5%) than without (12.9%) AML augmentation (p<0.05). Echographic study showed a lower incidence of recurrency of mitral insufficiency when AML augmentation had been performed (grade 2: 9% and grade 3: 3%) as compared to no AML augmentation (grade 2: 35% and grade 3: 14%) (p<0.05). The mitral orifice area was larger (AML augmentation: 2.2 + 0.3 cm2 vs no AML augmentation: 1.8 + 0.4 cm2). CONCLUSION: ring annuloplasty alone failed to correct rheumatic mitral insufficiency in all cases. AML augmentation improved the quality of the repair and decreased the risk of reoperation.

Adult↗

A case of early failure of the freestyle stentless bioprosthesis due to cuspal tear.

We report an unusual case of early structural failure of the Freestyle stentless bioprosthesis 22 months after initial implantation. A 71-year-old woman, who had undergone stentless valve implantation by the subcoronary method, presented with a new diastolic murmur and progressive congestive heart failure 20 months after the initial implantation. Reoperation was performed using a stented bioprosthesis. The explanted prosthesis showed a tear along the annulus in one cusp. There were no findings of bacterial endocarditis or other macroscopical changes including calcification, thrombus attachment and pannus formation. It is believed that the cause of the cuspal tear was primary tissue failure. Further study is needed to clarify the incidence of this event.

Aged↗

Chordal-sparing mitral valve replacement using artificial chordae tendineae for rheumatic mitral stenosis: experience of the "oblique" method.

Chordal-sparing mitral valve replacement (CSMVR) has been proven to be beneficial for postoperative left ventricular (LV) function. In patients with mitral stenosis, however, diseased chordae tendineae (CT) often have to be replaced using artificial CT to achieve CSMVR. Previously, we reported that resusupension of artificial CT in an oblique direction enhances systolic LV function. Among 40 consecutive patients with mitral valve replacement (MVR), 17 (4 men and 13 women; mean age 66.5 years) with rheumatic mitral stenosis underwent CSMVR with oblique resuspension. Echocardiography was done before the operation, early (mean 25 days) after the operation, and at a late stage (mean 14 months). There was no mortality or major morbidity. LV ejection fraction late after the operation (68 +/- 8%) was better than that in the early period (61 +/- 8%, p < 0.01), and comparable to the preoperative level (65 +/- 9%). The oblique method may help to improve the results of MVR.

Aged↗

Posterior leaflet preservation during mitral valve replacement for rheumatic mitral stenosis.

Mitral valve replacement with posterior leaflet preservation was shown beneficial for postoperative left vetricular (LV) performance in patients with mitral regurgitation. Some authors find it beneficial even for the long term LV function. We investigated a long term effect of this technique in patients with rheumatic mitral stenosis. We studied 20 patents with mitral valve replacement due to rheumatic mitral stenosis, in the period from January 1988 to December 1989. In group A (10 patients) both leaflets and coresponding chordal excision was performed, while in group B (10 patients) the posterior leaflet was preserved. In all patients a Carbomedics valve was inserted. We compared clinical pre and postoperative status, as well as hemodynamic characteristics of the valve and left ventricle in both groups. Control echocardiographyc analysis included: maximal (PG) and mean (MG) gradients; effective valve area (AREA); telediastolic (TDV) and telesystolic (TSV) LV volume; stroke volume (SV); ejection fraction (EF); fractional shortening (FS) and segmental LV motion. The mean size of inserted valve was 26.6 in group A and 27.2 in group B. Hemodynamic data: PG (10.12 vs 11.1); MG (3.57 vs 3.87); AREA (2.35 vs 2.30); TDV 126.0 vs 114.5); TSV (42.2 vs 36.62); SV (83.7 vs 77.75); EF (63.66 vs 67.12); FS (32.66 vs 38.25). Diaphragmal segmental hypokinesis was evident in one patient from group A and in two patients from group B. In patients with rheumatic stenosis, posterior leaflet preservation did not have increased beneficial effect on left ventricular performance during long-term follow-up. An adequate posterior leaflet preservation does not change hemodynamic valvular characteristics even after long-term follow-up.

Echocardiography↗

Paravalvular leak and other events in silzone-coated mechanical heart valves: a report from AVERT.

BACKGROUND: The Artificial Valve Endocarditis Reduction Trial (AVERT) was designed to compare endocarditis rates in Silzone versus conventional valves. Recruitment ended January 21, 2000, because of higher rates of paravalvular leakage in patients receiving the Silzone prosthesis. The present analysis determined late event rates that might be used in the management of approximately 36,000 patients who have received the Silzone prosthesis. METHODS: A total of 807 patients in 19 centers in North America and Europe were randomized. Mean age was 61+/-11 years; 41% were women. Operations included aortic valve replacement in 59%, mitral valve replacement in 32%, and aortic and mitral valve replacements in 9%; 41% had concomitant operations (26% coronary artery bypass grafting). RESULTS: Major paravalvular leakage (followed by repair, explant, or mortality) occurred in 18 of 403 patients receiving Silzone valves and 4 of 404 patients without Silzone valves (2-year event-free rates: 91.1% versus 98.9% conventional, p < 0.003). Similarly, 2-year freedom from any explant was lower in the Silzone arm (19 versus 2 events; 90.1% versus 99.4%, p = 0.0002). Rates of mortality and stroke were similar during follow-up. CONCLUSIONS: Continued follow-up of AVERT supports the conclusion that the Silzone prosthesis has increased risk of paravalvular leakage requiring reoperation. Overall survival is similar in the two groups.

Aortic Valve↗

A case in which biventricular assist device support was required after aortic valve replacement with a bioprosthetic valve.

We report the case of a 45-year-old man with severe aortic regurgitation. The patient underwent aortic valve replacement with a bioprosthetic valve, but was unable to be weaned from cardiopulmonary bypass (CPB). Intraoperative coronary angiography revealed stenosis of the right coronary orifice, so an intra-aortic balloon pump was inserted and coronary artery bypass grafting to the right coronary artery was conducted; however, weaning from CPB again failed. Left ventricular assist using a Gyro centrifugal pump was performed between the left atrium and left femoral artery, along with right ventricular assist using a Nikkiso centrifugal pump between the right atrium and pulmonary artery. Flow rates averaged from 2.0 to 2.8 l/min for the left-side ventricular assist device (VAD) and 2.1-3.8 l/min for the right-side VAD. The bypass rate reached approximately 70% at maximum. No thromboembolic events were documented during VAD support. The patient underwent explantation of VADs on postoperative day 4. No thrombus was identified on the bioprosthetic aortic valve by transesophageal echocardiography. The left-side pump displayed no thrombus, while the right-side pump had a small thrombus at the shaft. The patient was discharged from the hospital and was alive as of 2 year postoperatively. To the best of our knowledge, no clinical study has yet compared the antithrombotic properties of two centrifugal pumps in one patient where mechanical support was performed for the same duration and flow rate.

Aortic Valve↗

[Model fluids of blood for in vitro testing of artificial heart valves].

The increasing development and implantation of artificial organs subject to perfusion with human blood once implanted (grafts, heart-valve prostheses and assist systems) require extensive testing of hydrodynamic performance in mock circulation models. As human blood ist not always available in the necessary quantities, different fluids (water, saline or glycerine solutions) are employed for measurements of flow characteristics. However, these model fluids do not possess the non-Newtonian rheological properties of blood. In addition, they do not allow estimation of possible blood damage. Aqueous solutions of high molecular weight polyacrylamides (PAA) have rheological properties similar to blood, displaying also molecular degradation due to shear stress in the flow. Therefore, they were used as model fluid for blood. Different model solutions were compared to blood with regard to their influence on characteristic flow parameters of mechanical heart valves. Likewise, the shear damage of erythrocytes could be compared to flow-induced polymer degradation. It was shown that PAA solutions in definite concentrations are suitable models for blood, not only in terms of non-Newtonian rheology, but also in terms of estimation of hemolytic potential of artificial heart valves.

Acrylic Resins↗