Tricuspid valve replacement with the bileaflet St. Jude Medical valve prosthesis Case histories of 39 patients who underwent tricuspid valve replacement with the St. Jude Medical prosthesis between June 1979 and August 1992 were reviewed in March 1993. The average patient age at the time of the operation was 46 ± 11 years (range from 17 to 68 years). Concomitant mitral and/or aortic valve replacements were performed in 30 patients. AU patients were given warfarin to maintain thrombotest between 10 % to 25 %. This number was between 2.8 to 1.6 times the control value in the International Normalized Ratio of prothrombin time. Three operative deaths occurred (7.7%). Among six late deaths, two patients died suddenly of unknown causes, and the remaining patient deaths were not valve-related. The actuarial survival rate at 14 years was 54.7%. Valve thrombosis occurred in one patient and was successfuUy treated with intravenous urokinase. This was the only valve-related complication (0.67% /patient-year), No reoperations were necessary in the tricuspid position. In conclusion, the St. Jude Medical valve is our choice of prosthesis for tricuspid valve replacement in adult patients who can receive proper anticoagulation therapy. (J THoRAe CARDIOVASC SURG 1994;108:888-92)
Kiyoharu Nakano, MD, Hitoshi Koyanagi, MD, Akimasa Hashimoto, MD, Goro Ohtsuka, MD, and Chisato Nojiri, MD, Tokyo, Japan
h e choice of valve substitutes for the tricuspid position has been controversial. Although excellent hemodynamic and long-term results with the St. Jude Medical valve prosthesis (St. Jude Medical, Inc., St. Paul, Minn.) in both the aortic and mitral positions have been widely reported, 1-5 littie is known of its long-term clinical performance in the tricuspid position/' The present study represents our 14-year experience with the St. Jude Medical valve prosthesis for tricuspid valve replacement (TVR) in adult patients. Methods Patients. From June 1979 to August 1992, 39 adult patients underwent TVR with the S1.Jude Medical valve prosthesis: The size of the prosthesis was 27 mm in 3 patients, 29 mm in II From the Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women's Medical College, 8-1 Kawada-cho Shinjuku-ku, Tokyo 162, Japan. Received for publication Feb. 10, 1994. Accepted for publication June 16, 1994. Address for reprints: Hitoshi Koyanagi, MD, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women's Medical College, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162, Japan. Copyright @ 1994 by Mosby-Year Book, Inc.
0022-5223/94 $3.00 + 0 12/1/58419
888
patients, 31 mm in 18 patients, and 33 mm in 7 patients. An isolated TVR was performed in 6 patients. Additional procedures performed are shown in Table.1. Concomitant or prior mitral valve replacement (MVR) was performed in' J7 patients. Concomitant MVR and aortic valve replacement (AVR) or AVR with prior MVR was performed in 12 patients. The prostheses used in the mitral or/and aortic position(s) were mainly the S1. Jude Medical valve. Preoperative characteristics of the study population are shown in Table II. Previous cardiac operations had been performed once in 13 patients and twice in II patients. Previous TVR had been performed in 2 patients. Nine patients had received previous tricuspid annuloplasty by a modified De Vega method. The causes of the tricuspid valve lesion were atrioventricular defect (n = 3), Ebstein's anomaly (n = 2), congenital tricuspid regurgitation (n = I), infective endocarditis (n = 2), and trauma (n = I). In 30 cases, the patients had concomitant mitral valve disease. Obvious hemodynamic tricuspid stenosis with fusion of the commissures had occurred in 4 cases. I n the remaining cases, tricuspid regurgitation was caused by a dilated tricuspid anulus and elongation of the chordae, probably the result of mitral valve disease. The annuloplasty was not effective in those cases. Thirty-two patients had preoperative atrial fibrillation and had sustained atrial fibrillation after the operation. Postoperative follow-up. Surviving patients have been examined by cardiologists or cardiovascular surgeons in the outpatient clinic, in our institute or at local hospitals, at least once every 2 months. Patients who had been examined in local hospitals were interviewed by telephone in March 1993. We were successful in following up 100 percent of the patients. The
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Table II. Preoperative patient characteristics
Table I. Operative procedure Isolated TVR TVR with MVR MVR + LA thrombectomy MVR + LA plication MVR+AVR A VR + mitral repair AVR* ASO closure ASD closure + MVP Repair of ruptured SV
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Age (yr) Mean ± SO Range Sex Male Female NYHA
6 IS I I
II I I
II III
1 1 I
IV Cardiac rhythm Normal sinus Atrial fibrillation Pacemaker Etiology of tricuspid lesion Congenital Infective endocarditis Traumatic Rheumatic Resulting from mitral disease Previous operation Primary Secondary Tertiary
nCR Tricuspid valve replacement; MVR, mitral valvereplacement; LA, left atrial: _-jVR. aorticvalvereplacement; ASD, atrial septaldefect; MVP, mitral valvulopiastv; S V. sinusof Valsalva. "This patient underwentprior MVR.
follow-up duration thus far has been 13 years 9 months. The total follow-up has been 149 patient-years. The definitions of events and the methods of analyzing the results follow the guidelines for reporting morbidity and mortality after cardiac valve operations as published in this JOURNAL in 1988. 7 Thromboembolism was restricted to pulmonary embolisms, excluding systemic embolism. The actuarial curves were constructed by the standard nonparametric Kaplan-Meier method.The resultsare presentedwithstandard error. Anticoagulant therapy. All patients were given warfarin potassium as soonas oral administrationwas possible. The criteria for an adequate anticoagulation state ranged from 10% to 25% in the thrombotest, which is equivalent to from 2.8 to 1.6 times control in the prothrombintime InternationalNormalized RatioS The thrombotest was performed at least once every 2 months. Until the thrombotestcame within the optimal range, the patients were administered intravenous drip infusions of urokinase (12,000 units/day). Results Three operative deaths occurred. One patient had received triple valve replacement (AVR, MVR, and TVR) 14 years after an AVR and open mitral commissurotomy and died 30 days after the operation. The other two patients underwent both MVR and TVR. One patient had received open mitral commissurotomy 21 years earlier and MVR 12 years earlier. The other patient had undergone mitral valvuloplasty and tricuspid annuloplasty 8 years earlier. These patients died 51 days and 28 days, respectively, after their operations. All three patients died of multiorgan failure after persistent congestive heart failure. The operative mortality rate was 7.7%.
Late death occurred in six patients. The causes oflate death were congestive heart failure (n = 1), cerebral embolism (n = 1), respiratory failure (n = 1), and renal failure (n = 1). Sudden death of unknown cause occurred in tWO patients. One patient who received a previous AVR and MVR twice underwent triple valve replacement.
TVR (once) TVR (twice) TAP PA systolic pressure (32 cases) Mean ± SO (mm Hg) Range (mm Hg) Mean RA pressure (34 cases) Mean ± SO (mm Hg) Range (mrn Hg)
46 ± II 17-68
13
26 7 20 12 4 32 3
6 2
1 4
26 15 13 11
2 2
9 45 ± 17
24-88 14 ± 5 3-22
SD, Standard deviation; NYHA, New York Heart Association; TVR, tricuspid valvereplacement; TAP, tricuspidannuloplasty; PA, pulmonaryartery; RA, right
atrial.
Another patient with an atrioventricular defect underwent MVR and TVR. The actuarial survival after 14 years, including operative deaths, was 54.7 ± 15.1% (Fig. 1). Valve thrombosis occurred in one patient 7 months after the operation. The valve click was audible, and no systolic murmur was present. However, right-sided heart failure was persistent. Cinefluoroscopy showed that one disc was stuck in a closed position and the other disc moved normally. The patient was successfully treated with the intravenous administration of 240,000 IV of urokinase. Subsequent cinefluoroscopy revealed that the excursion of the both leaflets was full and equal. The patient remained in stable condition for 12 years after the valve thrombosis. The linearized rate of valve thrombosis was 0.67% /patient-year. No instances of structural deterioration, nonstructural dysfunction, anticoagulant-related hemorrhage, prosthetic endocarditis, or pulmonary
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54.7%
30 2 5 2 4 1 6 1 2 1 0
6
4
3
3
3
3
2
Years after operation Fig. 1. Actuarialsurvival curve, including operative deaths.Numbersabove the horizontal axisrepresent the number of patients eligible for analysis.
embolism occurred. However, a fatal cerebral embolism occurred in one patient who underwent a concomitant A VR and MVR. We determined that the episode was not related to the TVR. Simultaneous pacemaker implantation was performed for complete atrioventricular block in two patients, atrial standstill in two patients, sick sinus syndrome in one patient, and atrial fibrillation with bradycardia in one patient. In three patients a pacemaker implantation was required in the late postoperative period. Electrical myocardial leads that had been implanted at the time of the TVR operation were used for the pacemaker implantation. Although the two patients who died suddenly were not censored at the time of death, one instance of valve thrombosis was the only valve-related complication. The actuarial freedom from valve thrombosis and all valverelated complications 14 years after the operation was 96.9 ± 3.1% (Fig. 2). No reoperations for the tricuspid valve were performed. The actuarial rate of freedom from valve-related mortality and reoperation was 100%. However, one patient underwent a second replacement of the mitral valve prosthesis for severe hemolytic anemia. The actuarial rate of freedom from all operative deaths and all valve-related deaths including sudden unexplained death and nonfatal valve-related morbid events at 14 years was 80.5 ± 6.7% (Fig. 2). Discussion The present study demonstrates the excellent performance of the St. Jude Medical valve in the tricuspid posi-
tion, with a low incidence of valve-related complications. Valve thrombosis occurred in only one patient, who was successfully treated with intravenous urokinase. This was the only instance of a valve-related complication. Valve reconstruction is preferred for severe regurgitation of the tricuspid valve resulting from mitral valve disease. In the same period of this series, tricuspid annuloplasty, mostly De Vega's technique, was performed in 258 patients. In no case was an annuloplasty ring device inserted in the tricuspid position. In the patients who received a prosthetic valve, fusion of the commissures and/or elongation of the chordae were prominent and valve reconstruction was impossible. The major reason for the controversy regarding the choice of a mechanical prosthesis for the tricuspid position has been the high rate of valve thrombosis reported after prior TVRs with mechanical valve prostheses.f':' Boskovic and associates':' have reported their experience with the Bjork-Shiley tilting disc valve (standard type) in the tricuspid position. Seven of28 patients (25%) experienced thrombosis, an incidence of 6.8%/patient-year. During the first 24 hours of thrombolytic treatment with streptokinase, complete regression of clinical, cineangiographic, and echocardiographic signs of thrombosis were seen in all seven patients. However, recurrent thrombosis was observed in three patients 4, 7, and 14 months after their initial treatment with streptokinase. Repeat thrombolytic treatment with streptokinase was successful in all three cases. Regarding the St. Jude Medical valve, although tricuspid valve thrombosis has been reported/': 14 little is
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1 - - - - - - - - - - - - - - - - - 8 96.9%
Events a. Valve-related complication b. a + reoperatlon + operative death + sudden death
Fig. 2. Actuarial rates for freedom from events.
known about the incidence of valvular thrombosis. Singh, Feng, and Sanofsky? have reported long-term results of TVR with the St. Jude Medical valve in 14 patients. Two of their patients abruptly stopped anticoagulation therapy and partial valvular thromboses developed 4 and 6 weeks later. 'However, no valvular thromboses developed in patients who complied with the anticoagulation regimen. The configuration of the right ventricle is wedge shaped. The subvalvular trabecular tissue may restrict the excursion of the valve prosthesis. Sanfelippo and coworkers'' have demonstrated instances with the Starr-Edwards ball valve (Baxter Healthcare Corp., Edwards Div., Santa Ana, Calif.) in which the excursion of the ball was restricted by the subvalvular muscular tissue with resulting thrombotic obstruction of the orifice. Weerasena, Spyt, and Bain12 have reported their experience of 79 patients with the Bjork-Shiley disc valve (Shiley, Inc., Irvine, Calif.) in the tricuspid position. In seven of 66 patients, malfunction of the tricuspid prosthesis was caused by tissue ingrowth. The tissue ingrowth on the ventricular side of the prosthesis may relate to the subvalvular components of the tricuspid valve and the turbulence that occurred downstream from the disc. Because the St. Jude Medical valve is a low-profile prosthesis, the valve can safely be implanted without restricting leaflet excursion by the subvalvular muscular tissue. Furthermore, complete central flowcan be obtained, and no strut is present in the turbulence that occurs downstream from the disc. These features can be advantageous in protecting the prosthesis from valvular thrombosis or tissue ingrowth. Thrombolytic therapy for prosthetic valve thrombosis
in the tricuspid position was successful in our case and in most cases that have been reported from other institutes.P: 15. 16 Thrombolytic therapy for prosthetic cardiac valve thr-ombosis in the aortic or the mitral position has been controversial, because systemic embolisms often occur shortly after the treatment.P: 16 However, pulmonary embolisms have not been reported during thrombolytic therapy for thrombosed prosthetic valves in the tricuspid position. Therefore, thrombolytic therapy has been the choice of treatment. A pulmonary embolism is often more difficult to diagnose than a systemic thromboembolism. There were no clinical features of pulmonary embolisms in our patients and in the series of TVRs with mechanical valves at other institutes, despite a higher incidence of valve thrombosis after TVR than after AVR or MVR. However, minor pulmonary embolism may have occurred in our series and the series of patients who received TVR at other institutes. It is impossibleto implant intravenous pacemaker leads after a TVR with a mechanical valve. Therefore, to provide for an instance in which a pacemaker implantation may be required in the future (for example, atrial fibrillation with bradycardia or junctional bradycardia rhythm), we implanted a permanent electrical pacemaker probe on the myocardium at the time of the TVR. The lead is left in the subcutaneous pocket created in the abdominal wall at the time of the operation. Then, the pacemaker can be implanted easily in the pocket anytime after the operation. Use of a bioprosthesis is an alternative to use of a mechanical prosthesis for a TVR, because a bioprosthesis can be expected to be more durable in a low-pressure chamber than in the systemic circulation. However, in the
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case of multiple valve replacements, if the bioprosthesis is implanted in the tricuspid position and a mechanical valve is implanted in the mitral or aortic position, the durability of the bioprosthesis in the tricuspid position might be less reliable than that of a mechanical valve in the mitral position. Further, the patient has less of the advantages afforded by a bioprosthesis, because warfarin anticoagulation is necessary for a mitral or aortic mechanical prosthesis. Because the bileaflet St. Jude Medical valve has excellent hemodynamic characteristics.l?: 18 even during rapid pacing or with atrial fibrillation in the tricuspid position, 18 we have used it for patients who underwent TYR. The encouraging results from our 14-year retrospective study on the St. Jude Medical valve prosthesis justify our choice of the valve prosthesis in the tricuspid position. REFERENCES 1. Emery RW, NicoloffDM. St. Jude Medical cardiac valve prosthesis: in vitro studies. J THORAC CARDIOVASC SURG 1979;78:269-76. 2. Wortham DC, Tri TB, BowenTE. Hemodynamicevaluation of the St. Jude Medical valve prosthesis in the small aortic anulus. J THORAC CARDIOVASC SURG 1981;81:61520. 3. Arom KV, Nicoloff DM, Kersten TE, Northrup WF III, Lindsay WG, Emery RV. Ten years' experiencewith the St. Jude Medical valveprosthesis. Ann Thorac Surg 1989; 47:831-37. 4. Czer LSC, Chaux A, MatIoff JM, et al. Ten-year experience with the St. Jude Medical valve for primary valve replacement. J THORAC CARDIOVASC SURG 1990;100:4455. 5. Nakano K, Koyanagi H, Hashimoto A, et al. Twelveyears' experiencewith the St. Jude Medical Valveprosthesis. Ann Thorac Surg 1994;57:697-703. 6. Singh AK, Feng WC, SanofskySJ. Long-term resultsofSt. Jude Medical Valve in the tricuspid position. Ann Thorac Surg 1992;54:538-40. 7. Edmunds LH Jr, Clark RE, Conn LH, Miller DC, Weisel
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RD. Guidelinesfor reporting morbidityand mortality after cardiac valvularoperations.J THORAC CARDIOVASC SURG 1988;96:351-3. 8. SanfelippoPM, Giuliani ER, DanielsonGK, Wallace RB. Pluth JR, McGoon DC. Tricuspidvalveprostheticreplacement: early and late results with the Starr-Edwards prosthesis. J THORAC CARDIOVASC SURG 1976;71:441-5. 9. Bourdillon PDV, Sharratt GP. Malfunction of Bjork-Shiley valve prosthesisin tricuspid position. Br Heart J 1976; 38:1149-53. 10. Jugdutt BI, Fraser RS, Lee SJK, Rossall RE, Callaghan JC. Long-term survival after tricuspid valve replacement: results with sevendifferent prostheses. J THORAC CARDlOVASC SURG 1977;74:20-7. 11. Thorburn CW, Morgan JJ, Shanahan MX, Chang Yr. Long-term results of tricuspid valve replacement and the problem of prosthetic valve thrombosis. Am J Cardiol 1983;51:1128-32. 12. Weerasena N, Spyt TJ, Pye M, Bain WHo Clinical evaluation of the Bjork-Shileydiscvalvein the tricuspidposition. Eur J Cardiothorac Surg 1990;4:19-23. 13. Boskovic D, Elezovic I, Boskovic D, et al. Late thrombosis of the Bjork-Shiley tilting disc valve in the tricuspid position: thrombolytictreatment withstreptokinase. J THORAC CARDIOVASC SURG 1986;91:1-8. 14. Bowen TE, Tri TB, Wortham DC. Thrombosisof a SI.Jude Medical tricuspid prosthesis: case report. J THORAC CARDIOVASC SURG 1981;82:257-62. 15. Ledain LD, Ohayon JP, Colle JP, Lorient-Roudaut FM, Roudaut RP, Besse PM. Acute thrombotic obstruction with disc valve prostheses: diagnostic considerations and fibrinolytic treatment. J Am Call CardioI1986;7:743-51. 16. Kurzrok S, Singh AK, Most AS, Williams DO. Thrombolytic therapy for prosthetic cardiac valve thrombosis. J Am Call Cardiol 1987;9:592-8. 17. Singh AK, Christian FD, Williams DO, et al. Follow-up assessmentof St. Jude Medical prosthetic valvein the tricuspid position: clinical and hemodynamic results. Ann Thorac Surg 1984;37:324-7. 18. Yamada T. In vitro hydrodynamiccharacteristicsof heart valves in tricuspid position. J Jpn AssocThorac Surg 1990: 38:1176-82.