Introduction
The Bjork-Shiley (BS) mechanical valve (ShileyCorp, Irvine, CA) was the first tilting disc valve used for the management of valvular heart disease(1). It was one of the most implanted mechanical valves between 1970s and 1980s; however, the valve’s production was stopped due to increased rate of fracture and disc escape that resulted in high patient mortality. We report a patient with a BS mitral valve prosthesis implanted in 1981 and still functioning.
Case Report
A 56-year-old female patient with the symptoms of leg swelling and dyspnea resulted from right ventricular failure was admitted to our clinic. She had undergone a mitral valve replacement with a BS tilting disc valve 36 years ago (Figure 1). Her echocardiogram revealed a well-seated, normally functioning prosthetic mitral valve with a mean pressure gradient of 5 mmHg. The left atrium was enlarged (8 cm) and the left ventricle remained normal in size. Left ventricular systolic function was normal with an estimated ejection fraction of 65%. The size of the right atrium was 12x10 cm, the diameter of the inferior vena cava was 4.1 cm. She had a severe tricuspid valve (TV) regurgitation and moderate pulmonary hypertension (systolic pulmonary artery pressure=50 mmHg). Tricuspid regurgitant velocity (TRV) was 3.3 m/s and tricuspid annular plane systolic excursion (TAPSE) was 13mm. We planned to perform only TV repair and not to touch the functioning BS valve.
After obtaining informed consent from the patient for both the surgery and the use of her medical records, resternotomy was carried out using cardiopulmonary bypass under the right femoral artery and vein cannulation. We decided to perform TV repair without an aortic cross-clamp, so we did not arrest the heart. We explored the TV through the right atriotomy while the heart was beating and implanted a 3D tricuspid annuloplasty ring (Size=32 mm, CONTOUR 3D®, Medtronic, USA).
Postoperative recovery was uneventful. The postoperative control echocardiography showed normal functioning BS valve in mitral position and no TV regurgitation was observed. She was discharged on the 5th postoperative day and she is doing well for 18 months after the procedure.
Discussion
The BS valve was the first tilting disc mechanical valve implanted for heart valve replacement(1). It was a low-profile mechanical valve with a Delrin disc. As this initial Delrin disc resulted in many structural complications such as wear or fracture, it was replaced by a pyrolytic carbon(2,3). However, these structural changes of the BS valve could not prevent the valve from strut fractures and in the end, BSV was recalled from the market. In the literature, there are many case series and reports that show structural deformities of the BSV(4-6). There are also case reports about BSV, which suggest that these valves are still functioning for 25- 42 years(7,8).
Prophylactic replacement of these valves which were prone to fracture was a concern especially in the early years of implantation of BSV and this peak of replacement was mainly due to infective endocarditis(9). The other peaks of replacement were mainly after the identification and publication of risk factors for outlet strut fracture in 1992(10). However, there have been debates on the necessity of these replacements. Guidelines for BS valve replacement were introduced to prevent unnecessary reoperations and these had a positive effect on treatment decisions(10).
Conclusion
The implanted valve in our patient has been functioning well for 36 years. The patient underwent a TV repair for TV regurgitation. BSV that was implanted in our patient had no structural abnormalities and it was functioning with a low-pressure gradient (5 mmHg). We decided to keep this normal functioning and non-destructed valve in place and not to perform a left atriotomy. We performed ring annuloplasty through right atriotomy and the postoperative course was uneventful. Since we did not touch the working BSV, we could perform beating heart TV repair and we think that these precautions resulted in an uncomplex operation and uneventful perioperative period.
Ethics
Informed Consent: Informed consent was obtained from the patient.
Authorship Contributions
Surgical and Medical Practices: A.T.K., K.Ö., S.G., O.E.G., Concept: A.T.K., N.B.T., A.B.B., Design: A.T.K., N.B.T, A.B.B., Data Collection or Processing: A.T.K., K.Ö., S.G., O.E.G., S.G., Analysis or Interpretation: A.T.K., N.B.T., O.E.G., Literature Search: A.T.K., Writing: A.T.K.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study received no financial support.