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Mechanical failure (leaflet disruption) of a porcine aortic heterograft Rare cause of acute aortic insufficiency
Mechanical failure (leaflet disruption) of a porcine aortic heterograft Rare cause of acute aortic insufficiency Use of the Hancock, glutaraldehyde-preserved, stented heterograft for aortic valve replacement has gained wide acceptance in the past 7 years. Nevertheless, very little is known about the long-term mechanical and pathological characteristics following implantation. A rare case is presented in which mechanical valve failure occurred secondary to leaflet disruption in the absence of infection 23 months after implantation. The literature is reviewed and the implications of this unusual complication are discussed.
Leland B. Housman, M . D . , F.A.C.C.,* William A. Pitt, M.D., F.R.C.P.(C),** John H. Mazur, M . D . , F.A.C.C.,** Britt Litchford, M . D . , * and Steven A Gross, M.D.,** San Diego, Calif.
Vjlutaraldehyde-preserved, stented porcine heterografts have been implanted in the aortic position for more than seven years. 1 - 3 However, there is little information concerning the long-term structural and pathological changes which occur after implantation of these stented porcine heterograft valves. Specifically, early bioprosthetic dysfunction in the aortic area has rarely been encountered, despite more than 30,000 implantations. 4, 5 This report describes a case of sudden mechanical failure (leaflet disruption) in the absence of infection of a Hancock aortic bioprosthesis (Hancock Laboratories, Inc., Anaheim, Calif.) 23 months after implantation. Case report D. S., a 48-year-old woman addicted to alcohol, underwent aortic valve replacement with a 25 mm. Hancock glutaraldehyde-stabilized heterograft on Oct. 30, 1975, for stenosis of a calcific, bicuspid aortic valve. Peak aortic gradient preoperatively was 70 mm. Hg, and the patient was in New York Heart Association Functional Class III. The proceFrom the Departments of Cardiac Surgery and Cardiology, Mercy Hospital and Medical Center, San Diego, Calif. 92103. Received for publication March 7, 1978. Accepted for publication May 4, 1978. Address for reprints: Leland B. Housman, M.D., 3563 Fourth Avenue, San Diego, Calif. 92103. *Department of Cardiac Surgery. "Department Of Cardiology. 2 1 2
dure was tolerated without problem, the postoperative course was benign, and the patient was discharged on the twelfth postoperative day. No anticoagulants were utilized. The patient returned to Functional Class I after the operation. She remained in stable condition until August, 1977, when she was admitted to the hospital with acute pulmonary edema. New physical findings included a Grade 2/6 blowing murmur of aortic insufficiency. Despite medical treatment in the hospital, congestive heart failure remained refractory and the intensity of the aortic insufficiency murmur increased to Grade 4/6 during the next 10 days. Repeat cardiac catheterization demonstrated 4+ aortic insufficiency. On Sept. 7, 1977, the heterograft aortic valve was replaced with a StarrEdwards Model 2400 track valve prosthesis. At operation there was no evidence of infection, thrombi, or technically induced problems (periprosthetic leak). All cultures (routine, fungal, acid-fast bacilli) before, during, and after rereplacement were negative. There was major disruption of one of the leaflets and a minor tear in a second one (Fig. 1). This separation of the leaflets from the stented frame had resulted in massive aortic insufficiency. Again, the procedure was remarkably well tolerated. The patient was returned to the operating room on the first postoperative day for evacuation of a mediastinal hematoma but thereafter had an uneventful convalescence. She was discharged on the twentieth postoperative day on a regimen of digoxin, furosemide, warfarin, and potassium supplementation. The patient has continued to do well and has no cardiac complaints at the present time (February, 1978). Discussion In the past 7 years, the Hancock glutaraldehydestabilized, stented porcine heterograft has gained wide acceptance, and large numbers are inserted annually in
0022-5223/78/0276-0212$00.20/0 © 1978 The C. V. Mosby Co.
Volume 76 Number 2 August, 1978
Mechanical failure of porcine heterograft
21 3
II|I1II|l[ll|lIll|lIll[ltll|IItl|IlIl|ll
1
Fig. 1. Leaflet disruption is easily seen from both the valve. (Specimen measured in centimeters.) the aortic r e g i o n . 2 , 3 ' 6 Little objective information has been collected concerning long-term mechanical stability, a point which continues to be the major question surrounding use of this type of valve. To our knowledge, mechanical failure of this prosthesis had not previously been reported to occur at less than 24 months in the aortic position in the absence of infection. 1_3, 7 In our patient, the sudden onset of symptoms occurred coincident with an increasing murmur of aortic insufficiency which had not previously been present. At operation, two of the three leaflets had torn loose from the stented frame. The absence of a perivalvular leak and of infection establishes this as a rare cause of mechanical failure. Whether or not the frequency of incidence and/or recognition of this serious complication will increase must await the passage of time, but all physicians using the Hancock glutaraldehyde-stabilized heterograft should be alerted to this possibility. REFERENCES I Pipkin, RD, Buch, WS, Fogarty, TJ: Evaluation of aortic valve replacement with a porcine xenograft without longterm anticoagulation. J THORAC CARDIOVASC SURG 71:
179-186, 1976
2
3
4
ntricular (left) and aortic (right) sides of the heterograft
2 Hannah, H, Reis, RL: Current status of porcine heterograft prostheses. A five-year appraisal. Circulation 54:Suppl 3:27-31, 1976 3 Reis, RL, Hancock, WD, Yarbrough, JW, Clancy DL, Morrow AG: The flexible stem. A new concept in the fabrication of tissue heart valve prostheses. J THORAC CARDIOVASC SURG 62:683-695, 1971
4 Fishbein, MC, Gissen, SA, Collins, JJ, et al: Pathologic findings after cardiac valve replacement with glutaraldehyde-fixed porcine valves. Am J Cardiol 40:331-337, 1977 5 Spray, TL, Roberts, WS: Structural changes in porcine xenografts used in substitute cardiac valves. Am J Cardiology 40:319-330, 1977 6 Cohn, LH, Lamberti, JJ, Castaneda, AR, et al: Cardiac valve replacement with the stabilized glutaraldehyde porcine aortic valve. Indications, operative results and follow-up. Chest 68:162-165, 1975 7 Cohn, LH: Durability of mechanical and biologic prostheses for aortic valve replacement, Chap 61, The Second Henry Ford Hospital International Symposium on Cardiac Surgery, JC Davila, ed., New York, 1977, Appleton-Century-Crofts, pp 380-388
Leland B. Housman, M . D . , F.A.C.C.,* William A. Pitt, M.D., F.R.C.P.(C),** John H. Mazur, M . D . , F.A.C.C.,** Britt Litchford, M . D . , * and Steven A Gross, M.D.,** San Diego, Calif.
Vjlutaraldehyde-preserved, stented porcine heterografts have been implanted in the aortic position for more than seven years. 1 - 3 However, there is little information concerning the long-term structural and pathological changes which occur after implantation of these stented porcine heterograft valves. Specifically, early bioprosthetic dysfunction in the aortic area has rarely been encountered, despite more than 30,000 implantations. 4, 5 This report describes a case of sudden mechanical failure (leaflet disruption) in the absence of infection of a Hancock aortic bioprosthesis (Hancock Laboratories, Inc., Anaheim, Calif.) 23 months after implantation. Case report D. S., a 48-year-old woman addicted to alcohol, underwent aortic valve replacement with a 25 mm. Hancock glutaraldehyde-stabilized heterograft on Oct. 30, 1975, for stenosis of a calcific, bicuspid aortic valve. Peak aortic gradient preoperatively was 70 mm. Hg, and the patient was in New York Heart Association Functional Class III. The proceFrom the Departments of Cardiac Surgery and Cardiology, Mercy Hospital and Medical Center, San Diego, Calif. 92103. Received for publication March 7, 1978. Accepted for publication May 4, 1978. Address for reprints: Leland B. Housman, M.D., 3563 Fourth Avenue, San Diego, Calif. 92103. *Department of Cardiac Surgery. "Department Of Cardiology. 2 1 2
dure was tolerated without problem, the postoperative course was benign, and the patient was discharged on the twelfth postoperative day. No anticoagulants were utilized. The patient returned to Functional Class I after the operation. She remained in stable condition until August, 1977, when she was admitted to the hospital with acute pulmonary edema. New physical findings included a Grade 2/6 blowing murmur of aortic insufficiency. Despite medical treatment in the hospital, congestive heart failure remained refractory and the intensity of the aortic insufficiency murmur increased to Grade 4/6 during the next 10 days. Repeat cardiac catheterization demonstrated 4+ aortic insufficiency. On Sept. 7, 1977, the heterograft aortic valve was replaced with a StarrEdwards Model 2400 track valve prosthesis. At operation there was no evidence of infection, thrombi, or technically induced problems (periprosthetic leak). All cultures (routine, fungal, acid-fast bacilli) before, during, and after rereplacement were negative. There was major disruption of one of the leaflets and a minor tear in a second one (Fig. 1). This separation of the leaflets from the stented frame had resulted in massive aortic insufficiency. Again, the procedure was remarkably well tolerated. The patient was returned to the operating room on the first postoperative day for evacuation of a mediastinal hematoma but thereafter had an uneventful convalescence. She was discharged on the twentieth postoperative day on a regimen of digoxin, furosemide, warfarin, and potassium supplementation. The patient has continued to do well and has no cardiac complaints at the present time (February, 1978). Discussion In the past 7 years, the Hancock glutaraldehydestabilized, stented porcine heterograft has gained wide acceptance, and large numbers are inserted annually in
0022-5223/78/0276-0212$00.20/0 © 1978 The C. V. Mosby Co.
Volume 76 Number 2 August, 1978
Mechanical failure of porcine heterograft
21 3
II|I1II|l[ll|lIll|lIll[ltll|IItl|IlIl|ll
1
Fig. 1. Leaflet disruption is easily seen from both the valve. (Specimen measured in centimeters.) the aortic r e g i o n . 2 , 3 ' 6 Little objective information has been collected concerning long-term mechanical stability, a point which continues to be the major question surrounding use of this type of valve. To our knowledge, mechanical failure of this prosthesis had not previously been reported to occur at less than 24 months in the aortic position in the absence of infection. 1_3, 7 In our patient, the sudden onset of symptoms occurred coincident with an increasing murmur of aortic insufficiency which had not previously been present. At operation, two of the three leaflets had torn loose from the stented frame. The absence of a perivalvular leak and of infection establishes this as a rare cause of mechanical failure. Whether or not the frequency of incidence and/or recognition of this serious complication will increase must await the passage of time, but all physicians using the Hancock glutaraldehyde-stabilized heterograft should be alerted to this possibility. REFERENCES I Pipkin, RD, Buch, WS, Fogarty, TJ: Evaluation of aortic valve replacement with a porcine xenograft without longterm anticoagulation. J THORAC CARDIOVASC SURG 71:
179-186, 1976
2
3
4
ntricular (left) and aortic (right) sides of the heterograft
2 Hannah, H, Reis, RL: Current status of porcine heterograft prostheses. A five-year appraisal. Circulation 54:Suppl 3:27-31, 1976 3 Reis, RL, Hancock, WD, Yarbrough, JW, Clancy DL, Morrow AG: The flexible stem. A new concept in the fabrication of tissue heart valve prostheses. J THORAC CARDIOVASC SURG 62:683-695, 1971
4 Fishbein, MC, Gissen, SA, Collins, JJ, et al: Pathologic findings after cardiac valve replacement with glutaraldehyde-fixed porcine valves. Am J Cardiol 40:331-337, 1977 5 Spray, TL, Roberts, WS: Structural changes in porcine xenografts used in substitute cardiac valves. Am J Cardiology 40:319-330, 1977 6 Cohn, LH, Lamberti, JJ, Castaneda, AR, et al: Cardiac valve replacement with the stabilized glutaraldehyde porcine aortic valve. Indications, operative results and follow-up. Chest 68:162-165, 1975 7 Cohn, LH: Durability of mechanical and biologic prostheses for aortic valve replacement, Chap 61, The Second Henry Ford Hospital International Symposium on Cardiac Surgery, JC Davila, ed., New York, 1977, Appleton-Century-Crofts, pp 380-388