Bjork-Shiley Prosthesis Research Articles

Postoperative Electrocardiogram in a Man with the Marfan Syndrome

A 53-year-old man with the Marfan syndrome had undergone aortic valve replacement with a Bjork-Shiley prosthesis for aortic regurgitation at another hospital 15 years earlier. At the same operation he had a Kay-type suture plication tricuspid annuloplasty of the posterior-septal commissure. He came to the cardiology clinic for preoperative clearance for inguinal hernia repair. An aortic regurgitation murmur was noted, and he admitted to exertional dyspnea. An electrocardiogram showed sinus rhythm, a normal P-R interval, and right bundle branch block. An echocardiogram revealed a dilated ascending aorta, severe aortic regurgitation due to a perivalvular leak, normal left ventricular systolic function, and pulmonary arterial hypertension with tricuspid regurgitation and a large right ventricle. Because of these findings he underwent a Cabrol procedure, i.e., a composite aortic valve and root replacement with reimplantation of the coronary arteries, and tricuspid valve replacement. Mechanical valves were used in both the aortic and tricuspid positions. A postoperative electrocardiogram showed sinus arrhythmia, at a rate of 88 beats/minute, that was completely dissociated from a regular, accelerated junctional rhythm, at a rate of 67 beats/minute, with right bundle branch block and left anterior fascicular block (Figure). Alternatively, the subsidiary pacemaker could have been in the left posterior fascicle. Many of the P waves were positioned where they would be expected to be conducted to the ventricles, but the perfectly regular ventricular rhythm indicated that none were. Thus, there was some degree of atrioventricular block. The relatively rapid subsidiary pacemaker may have contributed to the complete atrioventricular dissociation, and the atrioventricular block may have not been complete. Marriott has referred to this as “block-acceleration dissociation” (1). Figure Electrocardiogram recorded in the early postoperative period. See text for explication. Aortic valve replacement requires the surgeon to operate in close proximity to the atrioventricular conduction tissue (2). As a consequence, atrioventricular block and/or an accelerated junctional rhythm may develop, and the chances of this are greater if, as in this patient, the anatomy has been distorted by a prior operation. The rhythm disturbance in this patient is a combination of the two, i.e., a conduction disturbance in combination with increased automaticity. Other conditions, such as inferior myocardial infarction or digitalis toxicity, also may produce block-acceleration atrioventricular dissociation (1). Complete atrioventricular block is virtually never persistent in patients with inferior myocardial infarction or digitalis toxicity, and consequently these patients do not require permanent electronic pacing. In contrast, complete atrioventricular block developing after aortic valve surgery may be persistent, and those patients require permanent pacing (3, 4).

An unusual couple: Bjork-Shiley aortic and Smeloff-Cutter mitral prostheses — 42 years in action

In the early 1960s, in Stockholm, Drs Viking Bjork and Donald Shiley developed a tilting Delrin polymer disc valve, the so-called flat-disc Bjork-Shiley valve. At the same time in California, Dr Edward Smeloff was developing the first prosthetic valve to employ the ‘full-flow’ orifice concept thanks to a double set cage with an equator-seating ball (this is now known as the Smeloff-Cutter valve). Our patient was a 20 year-old woman ill due to a severe aortic and mitral stenosis caused by rheumatic disease when in 1970 she underwent a surgical double valve replacement with Bjork-Shiley aortic and Smeloff-Cutter mitral prostheses. Over the last decade, we have continuously followed the patient with six-month echocardiography: she is now 62 years old and she is in NYHA functional class II. The Bjork-Shiley aortic valve had a normal peak and a mean gradient with a mild perivalvular leakage (Fig. 1). Three-dimensional echocardiography allowed a complete study of the ‘full-flow’ orifice of the Smeloff-Cutter mitral valve: the prosthesis had normal haemodynamic profiles (Fig. 2). The prosthetic valves in our patient have been functioning well for more than 42 years; they represent the longest functioning Bjork-Shiley valve in the aortic position, and the second longest functioning Smeloff-Cutter valve in the mitral one.

Balloon Valvuloplasty of a Stenosed Bioprosthetic Tricuspid Valve

Percutaneous balloon valvuloplasty is rarely used in stenotic bioprosthetic valves, especially in the tricuspid position. A 72-year-old woman presented with right heart failure and was found to have a stenosed tricuspid bioprosthetic valve with thickened and fused cusps with an estimated valve area of 1 cm2 (Figure 1; Movie). She had undergone 2 previous open heart surgeries 19 and 20 years previously: first aortic valve replacement (Bjork-Shiley prosthesis, Shiley, Inc, …

Björk-Shiley Delrin prosthesis: 31 years of durability (and beyond)

1010-7940/$ — see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.ejcts.2005.11.034 preoperative echocardiographic assessment, was explanted for Bentall operation. After explantation the BSDP showed grooves on the occluder disc (Fig. 1). We report the case of a patient submitted to implantation of a Bjork-Shiley Delrin prosthesis (BSDP) on aortic position 31 years ago. The valve, despite optimal function at

Thirty years experience with heart valve surgery: isolated aortic valve replacement.

Thirty years have elapsed since the commencement of open-heart surgery in South Australia. A retrospective study was performed to evaluate mortality and complication rates and to identify factors associated with poor outcomes in all patients who underwent prosthetic aortic valve replacement during this period. Questionnaires and personal contact have been used to generate a combined database of pre-operative and post-operative information and long-term follow-up on 1322 patients who underwent isolated prosthetic aortic valve replacement at the Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital between 1963 and 1992. Complete survival follow-up data were obtained for 94% (1241) of the patients. The Bjork-Shiley valve was used in 66% (875) of the patients, a Starr-Edwards prosthesis in 31% (412), a St Jude prosthesis in 2% (26), and only 0.7% (9) bioprosthetic valves were inserted. The hospital mortality rate for the 30-year period was 2.9%. Progressively older and less fit patients have undergone surgery in recent years. The long-term survival of patients with aortic stenosis and aortic incompetence was not significantly different. Long-term survival was significantly shorter for patients with higher New York Heart Association (NYHA) functional classifications, and for patients in pre-operative atrial fibrillation. Pre-operative dyspnoea was significantly improved following aortic valve replacement. The rates of postoperative haemorrhagic and embolic complications were low by comparison with other published series. Aortic valve replacement can be performed with low hospital mortality and complication rates, and significant symptomatic improvement can be expected. Aortic valve recipients have a favourable prognostic outcome compared with an age- and sex-matched population, and risk factors that determine long-term survival can be identified pre-operatively.

Thirty years experience with heart valve surgery: isolated mitral valve replacement.

Thirty years have elapsed since the commencement of open-heart surgery in South Australia. A retrospective study was performed to evaluate mortality and complication rates and to identify factors associated with poor outcomes in all patients who underwent prosthetic mitral valve replacement during this period. Questionnaires and personal contact have been used to generate a combined database of pre-operative and post-operative information and long-term follow-up on 938 patients who underwent isolated prosthetic mitral valve replacement at the Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital between 1963 and 1993. Complete survival follow-up data were obtained for 92% (865) of the patients. The Starr-Edwards valve was used in 95% (891) of the patients, a Bjork-Shiley prosthesis in 2.5% (23) of the patients, and only 24 (2.5%) other valves were inserted. The hospital mortality rate for the 30-year period was 4.7%. The mean age of the patients who underwent surgery was greater in each of the three successive decades. A long-term survival advantage was observed for patients with mitral stenosis, however, survival was significantly shorter for patients with higher New York Heart Association (NYHA) functional classifications and for patients in pre-operative atrial fibrillation. Pre-operative dyspnoea was significantly improved following mitral valve replacement. The rates of postoperative haemorrhagic and embolic complications were low by comparison with other published series. Mitral valve recipients do not regain a normalized life expectancy, but risk factors that determine long-term survival can be identified pre-operatively to aid appropriate patient selection.

Streptokinase tretament for late thrombosis of the Bjork-Shiley tricuspid prosthesis; 12 years experience

Streptokinase tretament for late thrombosis of the Bjork-Shiley tricuspid prosthesis; 12 years experience

Improved Doppler assessment of the Bjork-Shiley mitral prosthesis using the continuity equation

To assess whether derivation of an effective mitral prosthetic valve area using the continuity equation provides an improved functional assessment of the Bjork-Shiley mitral prosthesis over the pressure half-time method, Doppler echocardiographic studies were performed in 43 patients 12 ± 7 months following the valve replacement. Effective valve orifice area used as the standard for comparison was determined by a hydraulic formula validated in vitro over a wide range of flow rates. All patients were clinically stable, without evidence of prosthetic dysfunction or aortic regurgitation. Prosthetic mitral valve orifice area determined by the hydraulic formula, by the continuity equation and by pressure half-time method for all prostheses sizes averaged 1.6 ± 0.46 cm 2, 1.83 ± 0.56 cm 2 and 2.34 ± 0.48 cm 2, respectively. Effective valve orifice area by the hydraulic formula had a strong correlation with that derived by the continuity equation ( r = 0.86; P < 0.0001; standard error of estimate (S.E.E.), 0.12 cm 2), but an insignificant correlation with the area calculated by the pressure half-time method ( r = 0.24). Proshetic mitral valve areas determined by the continuity equation and by pressure half-time method also correlated poorly ( r = 0.24). Pressure half-time was affected by heart rate, diastolic filling period, left ventricular fractional shortening and presence of atrial fibrillation ( P < 0.001). Thus, using the standard continuity equation to determine the orifice area of the Bjork-Shiley prosthesis in the mitral position provides improved assessment compared with the pressure half-time method.

Acute Cardiogenic Shock in a 62-Year-Old Man

(Chest 1993; 103:1237-38) A 62-year old man presented with hypotension and cardiorespiratory failure. Seven years previously, he was found to have severe mitral valve regurgitation due to myxomatous degeneration and underwent valve replacement with a 31-mm Bjork-Shiley prosthesis. Chronic anticoagnlation therapy was begun, and the patient did well over the next several years with normal valve function and only occasional palpitations. On the day of admission, the patient suddenly developed a burning chest sensation followed by severe dyspnea. When an ambulance team arrived, he collapsed, became hypotensive, and was intubated. On arrival to the emergency room he was unresponsive with a blood pressure of 72140 mm Hg and a pulse of 130 beats per minute. Examination revealed cool, clammy extremities, prominent crackles over all lung

Antiplatelet therapy in children with left-sided mechanical prostheses.

Valve replacement in children has always been associated with a high mortality, outgrowth of the prosthetic valve and difficulty in managing anticoagulation. Between January 1985 and April 1991, 20 patients (14 males and 6 females) underwent replacement of a left-sided cardiac valve. The median age at diagnosis was 21.6 months (1 to 120 months) and the median age at surgery was 85 months (11 to 213 months). Six patients were under 4 years of age. The site of valve replacement was aortic in 11 patients and left atrioventricular (AV) valve in 9 patients. The indications for aortic valve replacement were stenosis (6) and incompetence (5). The left AV valve was replaced in three patients following repair of AV septal defect, in one patient with corrected transposition of the great arteries (LTGA), in one patient with severe dysplasia and insufficiency, and in four patients for congenital mitral stenosis. A Bjork-Shiley prosthesis was used in three mitral and one aortic position, all the other patients receiving a St. Jude prosthesis: six mitral and ten aortic. All patients were anticoagulated (warfarin) for 3 months post implantation and then switched to a regimen of aspirin and persantine. There was no early or late death. Median follow-up was 12.3 months (4 to 72 months). Total follow-up was 59 patient-years or 708 months. There was one incident of thromboembolism (1.7%/patient-year) and four instances of bleeding (6.8%/patient-year). There was no valve thrombosis. Our regime of early warfarin followed by long-term antiplatelet therapy has been associated with a low incidence of thromboembolism and no valve thrombosis.

Myocardial Response to Pretreatment with L-Carnitine in Patients with Cardiac Valve Replacement

Twenty-one patients undergoing mitral valve replacement (MVR) with either isolated or combined valvular procedure were investigated to determine the ef fect of randomized and prospective administration of L-carnitine (car) chloride on myocardial function. Carnitine chloride (1800 mg/day, for seven consecu tive days just prior to MVR) was given orally to 9 patients (car-treated group) who were compared with 12 car-untreated patients (control group) subjected to the same procedure. Valve replacement was performed using the Bjork-Shiley mechanical prosthesis in aortic and mitral position and bioprosthesis in tricuspid position in both groups under cardiopulmonary bypass (CPB) associated with cold potassium-magnesium cardioplegia and systemic hypothermia. Preopera tive and intraoperative clinical profile (age, functional class, duration of aortic clamp and CPB, and level of hypothermia) was well matched in both groups. Free, short-chain acyl, long-chain acyl, and total Car were measured in the papil lary muscle excised adjacent to the free wall of the left ventricle at the time of valvular surgery. Heart rate and mean arterial pressure did not differ between the two groups. Cardiac index was 3.44 ± 0.08 and 3.82 ± 0.13 L/m2/min in the control and car-treated groups, respectively, (p &lt; 0.05). Dobutamine (DOB) infusion rate was 8.55 ± 0.73 and 5.57 ± 0.95 μg/kg/min in the control and car-treated groups, respectively (p &lt; 0.05). Left ventricular stroke work index (LVSWI)/DOB ratio was 4.50 ± 0.65 and 8.16 ± 1.72 g*m/m 2/beat/unit of DOB, in the control and car-treated groups, respectively (p &lt; 0.05). Long-chain acyl carnitine was 0.224 ± 0.031 and 0.460 ± 0.096 nmoL/mg noncollagenous protein in the control and the car-treated groups, respectively (p&lt;0.05). LVSWI/DOB ratio was well correlated with long-chain acyl carnitine in the tis sue, r = 0.74, n = 18, p&lt;0.001. These findings suggest that pretreatment with L-carnitine chloride appears to be effective in improving myocardial function in the early phase of reperfu sion following surgery and that long-chain acyl carnitine may play a key role in the enhancement of carnitine-meditated mitochondrial metabolic process.

Twelve-Year Comparison of a Bjork–Shiley Mechanical Heart Valve with Porcine Bioprostheses

Patients undergoing heart-valve replacement may receive a mechanical prosthesis, necessitating lifelong anticoagulant treatment, or a porcine bioprosthesis, which involves no absolute need for anticoagulants. We carried out a randomized, prospective trial to compare the durability of the Bjork-Shiley mechanical prosthesis (spherical tilting-disk model) and the incidence of valve-related complications with those variables in the Hancock and the Carpentier-Edwards porcine prostheses. The mitral valve was replaced in 261 patients, the aortic valve in 211, and both in 61; the survivors have been followed up for a mean of 12 years. We found a trend toward improved actuarial survival after 12 years with the Bjork-Shiley prosthesis, but this trend was not statistically significant (group with Bjork-Shiley valve vs. group with porcine valve [mean +/- SE], 51.5 +/- 3.2 vs. 44.4 +/- 3.2 percent; P = 0.08). There was no significant difference in the actuarial incidence of reoperation after 5 years, but after 12 years significantly more patients with a porcine prosthesis had undergone reoperation (8.5 +/- 2.0 vs. 37.1 +/- 4.1 percent, P less than 0.001). An analysis combining death and reoperation as end points for an actuarial assessment of survival with the original prosthesis intact confirmed that the patients with Bjork-Shiley Shiley prostheses had improved survival (48.6 +/- 3.2 vs. 30.0 +/- 3.0 percent after 12 years, P less than 0.001). Bleeding requiring hospitalization or blood transfusion was significantly more frequent in the patients with Bjork-Shiley prostheses (18.6 +/- 3.2 vs. 7.1 +/- 2.3 percent after 12 years, P less than 0.01). There was no significant difference after 12 years in the actuarial occurrence of embolism (Bjork-Shiley vs. porcine, 21.1 +/- 3.1 vs. 26.4 +/- 3.5 percent) or endocarditis (3.7 +/- 1.4 vs 4.6 +/- 1.6 percent). Survival with an intact valve is better among patients with the Bjork-Shiley spherical tilting-disk prosthesis than among patients with porcine bioprostheses, but use of the Bjork-Shiley valve carries an attendant increased risk of bleeding associated with the need for anticoagulant treatment.

The necessity of reoperation for patients with Bjork-Shiley, St Jude Medical, Hancock and Carpentier-Edwards prostheses

The purpose of this study was to determine the criteria of valve selection from the long-term results of Hancock, Carpentier-Edwards, St Jude Medical and Bjork-Shiley prostheses, taking into special account the frequency of reoperation. Reoperations on the Hancock bioprosthesis were performed on six patients for tissue leaflet disruption with an incidence of 2.2 per cent/patient-year. Reoperations on the Carpentier-Edwards bioprosthesis were performed on 24 patients for tissue leaflet disruption in 23 patients and prosthetic valve endocarditis (PVE) in one, with an incidence of 3.8 per cent/patient-year. Reoperations on the Bjork-Shiley prosthesis were performed in two patients for severe hemolysis, with an incidence of 0.32 per cent/patient-year. Reoperations on the St Jude Medical prosthesis were performed on 3 patients, for valve thrombosis in one patient, PVE in one, and hemolysis in one, with an incidence of 0.23 per cent/patient-year. The overall mortality rate was 20 per cent, or 7 patients, and the indications for reoperation affected this. Patients with primary tissue failure had a mortality rate of 10.3 per cent; those with a thrombosed valve, 0 per cent; those with hemolysis, 66.7 per cent; and those with valve infection, 100 per cent. A good chance of survival may be achieved in patients facing prosthetic valve complications by performing reoperation as soon as possible after early detection, since mortality is high following emergency reoperation and in patients with severe symptoms. Currently, we recommend mechanical prostheses for valve replacement except in patients over 70 years old and in younger patients with absolute contraindications to anticoagulative therapy.

Inadequacy of the gorlin formula for predicting prosthetic valve area

A total of 135 patients with normally functioning prosthetic aortic valves who were catheterized 6 months after placement of Hancock, modified Hancock or Bjork-Shiley prostheses were studied to determine the magnitude of error in Gorlin formula estimates of prosthetic aortic valve area. All patients were male, selected from 13 participating hospitals and routinely followed after valve replacement for 5 years. Hemodynamically determined Gorlin valve areas were compared with independently verified actual valve areas. Actual Hancock areas were measured from videotapes of valves exercised in a pulse duplicator flow model. Actual Bjork-Shiley areas were calculated directly from the valves' inner ring radius. Gorlin valve areas correlated poorly with actual valve areas (r = 0.39). The mean Gorlin formula error was 0.36 cm2 (standard deviation = 0.32). Gorlin areas overestimated actual areas by >0.25 cm2 in 43 patients (32%) and underestimated actual areas by >0.25 cm2 in 29 (21%). It was concluded that the Gorlin formula inaccurately predicts prosthetic valve area in the aortic position. Overreliance on this formula in assessing aortic stenosis could lead to errant clinical decisions.

Intermittent Obstruction of a Bjork-Shiley Mitral Valve Prosthesis — An Unusual Diagnosis Aided by Doppler Ultrasound

Obstruction of a Bjork-Shiley mitral valve prosthesis occurred in a 41 year old woman due to pannus tissue growing over the valve and impairing disc opening. The unusual intermittent nature of the obstruction was clearly demonstrated by Doppler ultrasound. The pannus was excised and the valve prosthesis replaced successfully with a Carpentier-Edwards xenograft.

Unsuspected amyloidosis and cardiac arrest following mitral valve replacement

We performed an autopsy on a 58-year-old female with previously unsuspected cardiac amyloidosis. One day prior to expiration the patient underwent a mitral valve replacement with a Bjork-Shiley prosthesis for mitral valve regurgitation. The valvular defect along with the massive myocardial amyloidosis which created a restrictive cardiomyopathy, were the etiology of the patient's poor cardiac output and subsequent demise.

Strut Fracture in a Bjork-Shiley Aortic Valve Prosthesis

Strut fracture can be a life-threatening adverse effect of mechanical prosthetic heart valves. This complication has occurred in the DeBakey, the Beall, the Cooley-Cutter and, most recently, the Bjork-Shiley valves. We report the case of a 35-year-old man who died suddenly 16 months after a 60 degree Bjork-Shiley Convexo-Concave heart valve prosthesis was inserted in the aortic position. At autopsy, the two welded attachments of the valve's outlet strut had fractured. The valve's tilting disc was found in his abdominal aorta.

A prospective study of platelet metabolism in rheumatic heart disease. Effect of prosthetic heart valve.

The metabolic activity of platelets in patients with advanced rheumatic heart disease (RHD) was estimated by measurement of heat production in a microcalorimeter. Twenty-nine patients were randomly selected and prospectively followed before and after valve replacement with Björk-Shiley prosthesis. Before the operation a significantly (P less than 0.02) elevated platelet heat production was found compared with normal subjects, 63 +/- 5 fW/cell and 59 +/- 4 fW/cell, respectively, probably due to the presence of a younger and metabolically more active platelet population. Platelet count before the operation was significantly lower than normal (P less than 0.001). Platelet heat production did not correlate with either type of valvular disease, the presence of valvular calcification or atrial fibrillation. After valve replacement the platelet heat production significantly decreased (P less than 0.001) to 58 +/- 5 fW/cell and the platelet count normalized. The highest incidence of thromboembolic manifestations was in the immediate postoperative period. The greatest reductions in platelet heat production. 19% and 27% were observed in two patients with thromboembolic events, as compared with an average of 4% for the rest of the operated patients without complications. The possible relationship between changes in platelet heat production and thromboembolism in patients with RHD is discussed.

Acute Intravascular Hemolysis Indicating Thrombosis of Bjork-Shiley Aortic Prosthesis

A patient with a Bjork-Shiley aortic prosthesis inserted two years and four months prior to receiving adequate anticoagulant therapy suddenly had severe intravascular hemolysis develop as a result of thrombosis of her aortic prosthesis. There was no notable hemodynamic compromise. The mechanism of the intravascular hemolysis is discussed.

Massive right ventricular outflow tract aneurysm after ventriculotomy for subvalvular pulmonic stenosis associated with peripheral pulmonary arterial stenoses

From the Pathology and Surgery Branches, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland . Manuscript received and accepted January 4, 1983, On leave from the Department of Pathology, Washington University, St. Louis, Missouri . ical tabulated sessile yellow mass, 23 X 22 X 14 mm . The chordae tendineae of this cusp were thickened and emerged from another yellow 20 X 12 X 8 mm mass that had largely replaced the posterior papillary muscle (Fig . 3) . The anterior cusp was normal. The mitral valve and the papillary muscles were excised and replaced by a 31 mm Bjork-Shiley prosthesis . The postoperative course was uneventful . Histologic examination of sections of the valve and thepapillary muscle tumors showed simple pure lipomas composed of mature fat cells (Fig . 4) .