The Ultracor tilting disc heart valve prosthesis in the aortic position: mid-term follow up

BACKGROUND AND AIM OF THE STUDY: The Ultracor valve is a recent introduction in the evolution of the tilting disc valve. This report summarizes a single surgeon's experience with the valve in the aortic position over a nine-year period. METHODS: Between 1990 and 1999, 94 patients received an Ultracor heart valve prosthesis in the aortic position. Forty-five patients (48%) had associated procedures, of which 32 (34%) were coronary artery grafts. Mean follow up was 2.6 years; total follow up was 229 patient-years. Follow up was 100% complete. RESULTS: The actuarial survival rate, including operative mortality rate, at five years was 82%. Actuarial freedom from valve-related death was 96% at five years. The linearized complication rate was 1.7%/year for late valve-related mortality, 1.7%/year for thromboembolism, 2.2%/year for anticoagulant-related hemorrhage (ACH), 1.3%/year for prosthetic valve endocarditis (PVE), and 1.7%/year for reoperation. The estimates of actuarial freedom from complications at five years were thromboembolism 89%, ACH 90%, PVE 96% and reoperation 96%. No structural failure or valve thrombosis was observed. CONCLUSION: Our experience over nine years showed the Ultracor heart valve prosthesis in the aortic position to be comparable with other currently evaluated mechanical heart valves in terms of durability and clinical results. Further study in this area should concentrate on the impact of valve type on left ventricular recovery post-implantation to provide additional information to the surgeon when selecting a valve from the plethora of choices available.     

Long-term follow up in patients receiving a small aortic valve prosthesis

BACKGROUND AND AIMS OF THE STUDY: Concern persists regarding the long-term effects of aortic valve replacement (AVR) in the small aortic root. METHODS: Twenty-eight patients (21 females, seven males; mean age 54.1+/-11.7 years; mean body surface area (BSA) 1.39+/-0.07 m2) who underwent AVR with a 19 mm mechanical valve more than 10 years previously at the authors' institute, were followed up. Long-term echocardiographic evaluations were performed in 18 of 21 survivors. RESULTS: Follow up in the 28 patients was complete for up to 19.2 years (mean 11.4 years); cumulative follow up was 318.1 patient-years. Actuarial survival rates at 5, 10 and 15 years were 88.5+/-6.3%, 72.0+/-9.0% and 72.0+/-9.0%, respectively. In general, NYHA class showed satisfactory improvement. Long-term echocardiography showed significant reductions in left ventricular (LV) wall thickness and mass index compared with preoperative values, despite the existence of pressure gradients. A negative correlation was found between the rate of reduction of LV wall thickness and BSA. CONCLUSION: Implantation of the 19 mm aortic mechanical prosthesis was viable in patients with a small aortic annulus, especially if their BSA was <1.45 m2.     

Long-term outcome after valve replacement with the omnicarbon prosthesis

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine whether long-term prognosis was affected by valve replacement with a tilting-disc prosthesis. METHODS: Surgical data were recorded prospectively for all (n = 153) valve replacement cases with the Omnicarbon prosthesis during the period February 1985 to January 1986. A rheumatic valvular pathology was present in 105 patients (68.6%). There were 78 (51%) aortic (AVR), 51 (33%) mitral (MVR) and 24 (16%) double (DVR) valve replacements. The follow up was 99% complete (n = 151). RESULTS: Mean follow up was 10.2+/-4.4 years (total 1,472 patient-years (pt-yr)). Survival at 10 years was 68+/-4% (71+/-5% AVR, 61+/-7% MVR), and this fell to 57+/-4% at 14 years. No structural failure was observed. Thromboembolic and hemorrhagic events were rare, with actuarial freedom from thromboembolism of 94+/-2% and 91+/-3% at 10 and 14 years, respectively. This low incidence of thromboembolism encouraged an ease in anticoagulation; hence the AVR and MVR cohorts had a median INR of 2.8, but a higher INR (3.4) was maintained in DVR patients. All prostheses had acceptable hemodynamic performance. No cases of hemolytic anemia were detected, and mean blood counts were within normal ranges. Lactate dehydrogenase values indicated minimal hemolysis, and were lowest after AVR (median LDH 93% normal) and highest after DVR (median LDH 136% normal). Functional evaluation showed an improvement in NYHA class that remained stable over 14 years. At follow up, 95% (75/79) of patients were in NYHA class I or II. CONCLUSION: Survival and quality of life after Omnicarbon valve implantation exceeded the authors' expectations. Functional capacity remains good, and valve-related complication rates are low. The Omnicarbon tilting-disc valve has been shown to provide reliable and satisfactory service in the long term.     

In-vivo evaluation of the BioPhysio valve prosthesis in the aortic position

BACKGROUND AND AIM OF THE STUDY: The new BioPhysio aortic prosthesis is a pericardial valve with a flexible stent that can be implanted with a single suture line. The study aim was to evaluate the in-vivo implantation characteristics, preservation of dynamic motion of the aortic root, and hemodynamic performance of this bioprosthesis. METHODS: The BioPhysio valve was implanted, in the aortic position, in 10 young adult male sheep. Transesophageal and intracardiac echocardiography were carried out postoperatively for hemodynamic evaluation. Cineangiography was performed both preoperatively and postoperatively to assess aortic root dynamics and to document the absence of aortic regurgitation. Cardiac output was monitored via a Swan-Ganz catheter, both preoperatively and postoperatively. RESULTS: The BioPhysio valve was implanted with interrupted mattress sutures in seven cases, and with continuous sutures in three cases. At a mean cardiac output of 5.9 l/min, the mean transaortic pressure gradients were 5.93 and 3.6 mmHg for the 19- and 21-mm valves, respectively, and the mean effective orifice areas were 2.08 and 2.65 cm2. Mean dilation of the aortic root, measured as the maximum expansion of the radiopaque frame in systole, was 9.01%. CONCLUSION: The unique flexible stent design of the new BioPhysio valve preserves the dynamic motion of the aortic root, by combining the hemodynamic benefits of stentless valves with the ease of implantation of stented bioprostheses.     

Long-term follow up of the Biocor porcine bioprosthesis in the mitral position

BACKGROUND AND AIM OF THE STUDY: The study aim was to review the long-term results of mitral valve replacement (MVR) with the Biocor porcine bioprosthesis, in order to investigate patient survival and valve-related complications. METHODS: Data were presented for 546 patients (320 females, 226 males; mean age 49.2 +/- 17.1 years) who underwent MVR with the Biocor porcine bioprosthesis between March 1983 and December 2000. Preoperatively, rheumatic fever was present in 42.3% of patients. Associated procedures were performed in 179 patients (32.7%), and myocardial revascularization in 54 (9.9%). Preoperatively, 41.9% of patients were in NYHA class IV. Postoperative follow up was conducted by telephone interviews, questionnaires, or examination of hospital records. RESULTS: The hospital mortality was 9.5% (n=52); of these patients, 30 died after their first MVR and 22 after mitral reoperation. Mortality after isolated MVR was 7.6%. The total follow up was 2,148.9 patient-years, and actuarial survival was 45.0 +/- 15.8% at 15 years. Freedom from structural valve deterioration (SVD) was 51.8 +/- 13.8% for patients aged <50 years, 88.7 +/- 5.1% for those aged 51-60 years, and 84.0 +/- 9.8% for those aged 61-80 years. The incidence of prosthetic valve endocarditis was low, with 88.8 +/- 6.1% non-recurrence in 15 years. Freedom from reoperation was 33.9 +/- 10.4%, and from thromboembolism was 82.3 +/- 15.0%. Freedom from valve-related mortality was 80.7 +/- 12.5% during a 15-year period. CONCLUSION: The 15-year clinical results with the Biocor porcine bioprosthesis in the mitral position were excellent in a young, predominantly rheumatic, patient population which, preoperatively, was in a grave clinical condition. The incidence of valve-related complications was low, as was that of SVD in patients aged >50 years.     

Medium-term follow up of pulmonary autograft aortic valve replacement: technical advances and echocardiographic follow up

BACKGROUND AND AIM OF THE STUDY: The Ross procedure (aortic valve replacement (AVR) with pulmonary autograft and pulmonary homograft replacement of pulmonary valve) was developed as a durable aortic valve substitute that avoids the need for anticoagulation and provides young patients with a long-lasting aortic valve substitute. Our seven-year follow up echocardiography data are reviewed. METHODS: Between May 1993 and March 2000, 40 adult patients (28 males, 12 females; mean age 33.3 years) underwent the Ross procedure at the Brigham and Women's Hospital for congenital aortic stenosis (n = 6), aortic insufficiency (n = 17) and mixed disease (n = 17). All patients had aortic root replacement with the pulmonary autograft and had no regurgitation after operation. Postoperative evaluation was conducted by transthoracic echocardiography, office visit and/or telephone interview. NYHA functional class, aortic and pulmonary valve function and aortic root dimensions were evaluated. RESULTS: One patient died postoperatively as a result of a low output state related to global left ventricular dysfunction. Four patients (10%) developed pulmonary homograft stenosis with a peak gradient >40mmHg; and six developed mild pulmonary stenosis. One patient had aortic insufficiency seven years postoperatively that required valve replacement. Eight patients developed mild dilatation (>37 mm) of the neoaortic root, and five of these had aortic insufficiency. One patient required transplantation at 40 months for restrictive cardiomyopathy. CONCLUSION: The Ross procedure is an effective means of AVR that can be accomplished with low perioperative morbidity and mortality if certain technical modifications are carried out. In this series of 40 patients with mid-term follow up, a significant number developed moderate pulmonary trunk stenosis, though echo characterization demonstrated good valve function.     

Extended follow up after isolated aortic valve replacement in the elderly

The present paper reviews the extended follow up of all patients aged >/=70 who underwent isolated aortic valve replacement at our institution in the 1980s. Patients were identified from the surgical database and clinical information was gathered. Long-term follow up information was obtained from the patient, their family, or doctor. Ninety-three patients aged >/=70 years (median 73, range 70-80) comprised the study population. The indication for surgery was aortic stenosis in 68 patients (73%). Fifty-two patients (56%) received an allograft valve, 17 (18%) a bioprosthetic valve, and 24 (26%) a mechanical prosthesis. The median hospital stay was 12 days (range 0-105 days). Five surgical deaths occurred. Detailed follow up was obtained for the 71 patients who died later, and the 16 living patients (one patient lost). The median length of follow up was 6.8 years (range 0.1-18.9 years). Patients who received an allograft aortic valve had a significantly better long-term survival (median 10.6, 95% confidence intervals (CI) 8.1-13.8 years) compared to those receiving mechanical or bioprosthetic valves (median 6.5, 95% CI 4.7-11.9 years), P = 0.03. For the entire group, survival was similar to the age- and sex-matched population. Of the 16 patients alive at follow up (mean age 87, range 83-92), most were free of angina (12, 75%) and heart failure (10, 63%). The conclusion from the current study is that isolated aortic valve surgery in the elderly, particularly with an allograft valve, is associated with an excellent long-term outcome. A survival benefit was demonstrated comparing allograft aortic valve replacement to other valve types.     

Mechanical versus biological valve prosthesis in the mitral position: a 10-year follow up of St. Jude Medical and Biocor valves

BACKGROUND AND AIM OF THE STUDY: During the past 30 years, the development of mechanical and biological valves has led to major improvements in patient survival. Here, we present long-term results obtained with both types of prosthesis. METHODS: At our institution, between 1985 and 1989, 158 patients received a Biocor porcine bioprosthesis, and 100 patients a St. Jude Medical (SJM) mechanical valve. Preoperatively, mean age, male:female ratio, NYHA functional class and pathology of mitral valve disease were similar in both groups. RESULTS: The 30-day mortality was 4.4% in the Biocor group and 4% in the SJM group, the major cause being congestive heart failure. Late mortality was 17.9% and 15.6% respectively in the two groups, but valve-related mortality was very low in both (1.3% versus 4.2%). Ten-year survival was similar in each group (77.8+/-3.4% versus 81.0+/-3.9%; p = 0.538). Ten-year freedom from anticoagulant-related hemorrhage was higher with Biocor prostheses (99.3+/-0.7% versus 90.9+/-3.1%; p = 0.007). Valve thrombosis was seen only in the SJM group, and structural valve degeneration (SVD) only in the Biocor group. Ten-year freedom from reoperation was lower in the Biocor group (84.9+/-3.2% versus 92.2+/-2.8%; p = 0.206). The significant causes of reoperation were SVD in the Biocor group and valve thrombosis in the SJM group. Freedom from prosthetic valve endocarditis was similar in both groups (96.3+/-1.6% versus 95.5+/-2.2%). CONCLUSION: As no difference was seen in survival and reoperation rates between patients receiving either bioprostheses or mechanical valves, the valve used will depend on the surgeon's choice and the type of patient, notably elderly patients who are intolerant of anticoagulation, and young women wishing to have children.     

Catheter entrapment in a Bj?rk-Shiley prosthesis in aortic position

This report describes a lethal complication which occurred during retrograde catheterization of the left ventricle across a Bj?rk-Shiley prosthesis. The authors were called upon to testify as experts in malpractice proceedings in this case. After an 8F Sones catheter had been passed through the small side orifice of the prosthesis and three ventriculograms had been carried out, it was apparent that the movement of the tilting disc valve was considerably impaired and that the catheter had become irreversibly trapped. As a consequence the patient died of irreversible left heart failure before an operation could be performed. Consequently passing a tilting disc valve can no longer be considered as completely safe. This procedure should only be used under exceptional circumstances requiring very strict indication. If such an intervention is necessary, then it should only be performed by experienced cardiologists, who should take all possible precautions to reduce risks.     

Isolated replacement of a prosthesis or a bioprosthesis in the aortic valve position

The operative results of 203 aortic prosthetic valve reoperations performed in 175 patients from 1974 through 1986 were reviewed to identify groups at greater risk. Two to 4 reoperations were performed in 23 patients. The mean interval between the first and second valve procedures was 74 +/- 57 months. The most common indications for reoperation were thrombosis of mechanical prostheses (25%), degeneration of homografts (22%) and mechanical valve dysfunction (19%). Eighteen patients (9%) died. This mortality rate was significantly higher (p less than 0.05) than that of primary valve procedures performed during the same period. Mortality rates were higher among patients with prosthetic valve endocarditis (6 of 26 cases, 23%) and among those who underwent operation on an emergency basis (15 of 20, 25%). No significant correlation was found between mortality rates and the age or gender of the patients and the types of prostheses used originally.     

Streptokinase treatment of a thrombosed Bj?rk-Shiley prosthesis in the aortic position.

Dysfunction of a mechanical prosthetic valve caused by thrombus formation is usually treated surgically. A patient with a thrombosed Bj?rk-Shiley valve in the aortic position was treated successfully with intravenous streptokinase. The considerable improvement in the patient's clinical condition and the phonocardiographic, echocardiographic, and cinefluoroscopic evidence of normalisation of prosthetic valve function established the efficacy of thrombolytic therapy of a thrombosed prosthetic valve in this patient.     

Streptokinase treatment of a thrombosed Bj?rk-Shiley prosthesis in the aortic position.

Dysfunction of a mechanical prosthetic valve caused by thrombus formation is usually treated surgically. A patient with a thrombosed Björk-Shiley valve in the aortic position was treated successfully with intravenous streptokinase. The considerable improvement in the patient's clinical condition and the phonocardiographic, echocardiographic, and cinefluoroscopic evidence of normalisation of prosthetic valve function established the efficacy of thrombolytic therapy of a thrombosed prosthetic valve in this patient.     

Mid-term clinical and echocardiographic follow up of patients with CarboMedics valves in the tricuspid position

BACKGROUND AND AIM OF THE STUDY: Debate continues regarding tricuspid valve replacement (TVR) with a mechanical prosthesis. Experience with bileaflet prostheses is limited; hence the study aim was to explore early and mid-term outcome and hemodynamic data in patients with bileaflet CarboMedics prosthetic valves in the tricuspid position. METHODS: The study population included 25 patients (21 females, four males; mean age 50.5 +/- 13.4 years) who underwent TVR with a CarboMedics valve over a six-year period. Routine clinical examinations and details of transthoracic echocardiography (TTE) were reviewed. Additional TTE, transesophageal echocardiography (TEE) and fluoroscopy were performed as indicated. The number of previous cardiac operations was zero, one and two in 36%, 32% and 32% of patients, respectively. Previous tricuspid surgery was performed in eight cases (32%); concurrent mitral valve replacement was performed in 17 (68%). The hospital mortality rate was 24% and late mortality rate 12%. Seventeen early survivors (13 females, four males) were followed up for 46 +/- 28 months (range: 4-96 months). RESULTS: Among early survivors, the mean and peak transvalvular gradients were 4.0 +/- 1.7 and 7.9 +/- 3.3 mmHg, respectively. Commonly observed INR levels were >2.5 in seven patients (41%), and >3.0 in only three (18%). Five patients (29% of mid-term survivors) experienced a total of 13 episodes of obstructive valve thrombosis, mostly with inappropriate anticoagulation. One patient required emergency re-do surgery; the others responded initially to thrombolysis or intensified antithrombotic treatment, but experienced at least two additional relapses. Aside from thrombotic episodes, all patients but two were in NYHA functional class II-III, and all but four required diuretics. CONCLUSION: TVR with bileaflet mechanical valves carries a high perioperative mortality and mid-term morbidity. Among patients with poor or fair anticoagulation, these valves were associated with a high incidence of obstructive valve thrombosis. If poor patient compliance is anticipated, insertion of a bioprosthesis should be encouraged.     

Clinical experience with the 3F stentless aortic bioprosthesis: one-year follow up

BACKGROUND AND AIM OF THE STUDY: The 3F equine aortic bioprosthesis is a new stentless valve which is currently undergoing evaluation in a multicenter clinical trial and is considered to have superior hemodynamic performance. Herein is reported the authors' initial experience with the 3F valve, focusing on the hemodynamic performance of the device. METHODS: Between March 2002 and October 2003, 35 patients (age range 61-86 years) underwent aortic valve replacement with the 3F valve implanted in the subcoronary position. Evaluation of valve hemodynamic performance was assessed at discharge (postoperative day 5 +/- 2), at 3-6 months, and at 11-14 months' follow up by means of transthoracic echocardiography. The mean preoperative transvalvular pressure gradient was 63 +/- 14 mmHg. Before surgery, all patients were in NYHA class III or IV, despite aggressive medical treatment. Five patients underwent concomitant coronary artery bypass grafting. RESULTS: The implanted valve sizes ranged from 21 to 29 mm. There were no operative deaths and no major perioperative complications. After 12 months, mean pressure gradients for the 23-, 25-, 27- and 29-mm valves were 13, 13, 12 and 9 mmHg, respectively. Mean systolic pressure gradients and NYHA class were improved significantly after surgery. Mild signs of hemolysis and minimal central regurgitation were detected in some patients, but were of no clinical importance. Valve dysfunction or mechanical failure did not occur during the follow up period. CONCLUSION: Because of its flexible structure, the 3F aortic bioprosthesis is simple to implant, and no major adverse effects have been associated with such valve implantation at the authors' center. Transprosthetic gradients appeared to regress at 6-12 months' follow up. The durability of the device is yet to be established in ongoing long-term trials.