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Subvalvular stenosis of aortic prostheses
Subvalvular stenosis of aortic prostheses A complication of the suture buttress technique Pledgets of Dacron felt are often used to buttress sutures during the placement of prosthetic heart valves. This report describes 2 cases in which progressive stenosis of Starr-Edwards Model 6310 aortic valves was caused by tissue ingrowth over the pledgets, This complication should be considered in the differential diagnosis of late prosthetic valvular dysfunction.
G. Weinstein, M.D., A. J. Franzone, M.D., S. H. Stertzer, M.D., and E. Wallsh, M.D., New York, N. Y.
The attachment of a prosthetic heart valve to a friable, heavily calcified annulus is a persistent problem in the surgery of valvular heart disease. Separation of the prosthesis from portions of the annulus may lead to paravalvular insufficiency, severe hemolysis, and intractable myocardial failure.':" A current technique, first described by Weldon and co-workers, G utilizes reinforcing felt pledgets to prevent the sutures from cutting through a friable annulus. Although originally described for mitral valves, this method is now used for aortic and tricuspid valves as well.": 6 In this communication, we present 2 cases that illustrate the development of subvalvular aortic stenosis, a previously unreported complication of Dacron pledget use. Case report CASE 1. E. H., a 41-year-old woman with aortic stenosis and insufficiency secondary to rheumatic valvular disease, underwent aortic valve replacement in February, 1971. A No. 8 StarrEdwards (Model 2310) ball-valve prosthesis was inserted in the aortic annulus. Because of heavy calcification requiring extensive debridement, nine mattress sutures buttressed with Dacron felt
From Lenox Hill Hospital, New York, N. Y. 10021. Received for publication Dec. 7. t973.
pledgets on the ventricular surface of the aortic annulus were used to fix the valve in place. An acceptable systolic pressure gradient of 30 mm. Hg was present across the valve at the completion of the procedure. The patient made an uneventful recovery. On Dec. 21, 1971, the patient had an episode of supraventricular tachycardia with frequent ventricular premature contractions. She was successfully treated by direct-current cardioversion. On March 12, 1972, she was readmitted to the hospital for severe dyspnea and diaphoresis. At that time, the prosthetic valve sounds were normal. An aortic systolic ejection murmur present since the operation had increased in intensity during the postoperative period. Within hours, the patient became lethargic. She developed atrial fibrillation with a slow ventricular rate, followed by low output syndrome, ventricular tachycardia, and cardiac arrest. Postmortem examination revealed a subvalvular fibrous diaphragm with a narrowed orifice resulting from the ingrowth of fibrous tissue along the pledgets (Figs. 1 and 2). Death appeared to have resulted from the development of a critical degree of stenosis below the suture ring of the prosthetic aortic valve. CASE 2. N. P., a 65-year-old woman, had mitral and aortic valve replacement on Nov. 24, 1970, for rheumatic valvular disease. Size 4 and 8 Starr-Edwards (Models 6310 and 2310) were placed in the mitral and aortic positions, respectively. Because of heavy calcification in both areas, Dacron buttresses were employed circumferentially in the subannular area of each valve.
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The Journal of Thoracic a nd Cardiovascular Surgery
Fig. 1. Postmortem view of aortic prosthesis viewed from the left ventricular surface. Fibrous ingrowth is apparent across the valve orifice. A, Prosthetic sewing ring . B, Cut edge of fibrous ring . C, Intact fibrous membrane. D, Prosthetic metal ball. E, Mitral leaflet. The postoperative course was complicated by a moderate basilar artery-brainstern syndrome and respiratory insufficiency, which were managed by tracheostomy and assisted ventilation. She was discharged 2 months after the operation in satisfactory condition. On April 23, 1972, she presented with progressive and per sistent fatigue, fever , anemia, and transient multiple neurologic defects suggestive of systemic embolization. Ph ysical examination revealed norm al prosthetic valve sounds and a Grade 2/6 systo lic ejection murmur over the aortic are a and left sternal border. These findings had not changed since the operation. The patient underwent an exploratory cardiotomy on April 25, 1972. The aortic valve was covered with an adherent, slimy material which extended across the struts and through the valve ring. A fibrou s ring and the enclo sed D acron pled gets were excised after mobilization of the valve. A No. 9 Starr-Edwards aortic prosthesis ( Model 2320) was replaced in the original site without the use of reinforcing pledgets. The mitral valve was normal by direct inspection, without evidence of a fibrous ring. The patient had an uneventful recovery. Microscopic examination of the valve revealed fragments of hyalinized connective tissue and thrombus. Cultures of the valve and fibrou s ring were sterile.
Discussion
The technique of buttressing valve sutures over Dacron pledgets to prevent dehiscence
has become a useful adjunct in valve surgery." Progressive stenosis has not been previously reported. The 2 cases described here illustrate the formation of a dense fibrous subvalvular membrane with consequent severe aortic stenosis. Examination of both patients revealed a loud systolic ejection murmur at the aortic area and left sternal border with normal prosthetic valve sounds . The first patient had a gradual and unexplained increase in the intensity of the murmur. Late developments included arrhythmia, low cardiac output, systemic embolization, fever, and anemia. Several factors appear to contribute to the development of the subvalvular membrane. Extensive injury secondary to debriding large amounts of calcium from the aortic annulus and adjacent areas may result in an exuberant fibroblastic response. The use of Dacron as pledget material may encourage a hyperplastic tissue reaction, despite the fact that Dacron has a history of extensive use without complications . Last, a smaIl valve, i.e., Starr-Edwards size 8 (Model 2310), in the aortic area could cause turbulence and lead to the deposition of blood elements, thereby enhancing the ring formation.
Volume 68 Number 1 July, 1974
Sub valvular stenosis of aortic prostheses
19
buttresses to specific sutures in weakened areas rather than random circumferential insertion. Because of its diminished fibroblastic response, Teflon is probably the material of choice. The buttresses should be small ( 10 by 3 mm.) and should be placed well under the residual annulus and outer edge of the valve sewing ring. In add ition, the No. 8 Starr -Edwards valve should be restricted to those patients in whom a significant postoperative gradient will not be created. In cases in which a small valve is needed, a tilting-disc prosthesis is preferable. Finally , the occurrence of subvalvular aortic stenosis secondary to the use of pledgets must be included in the differential diagnosis of late complications of aort ic valve replacements. Summary
Fig. 2. Close-up view of the specimen shown in Fig. I, with the pro sthe sis removed. A , Aortic commissures. B , Fibrous "a nnulus." C, Dac ron pledget. D, Cut edge of fibrou s membrane. E, In situ suture. F , Mitral leaflet.
The extensive removal of calcium from the aortic annulus in preparation for valve replacement is obligatory. The thinned and weakened annulus must be supported, or operative tears with resultant bleeding and late valvular disruption may occur. Gago and Kirsh - report ed 50 cases of valve replacement in which Dacron pledgets were used to avoid periprosthetic tears. In these cases, the pledgets were fixed on the aortic side of the valve annulus, After the prosthesis is tied in place, the pledgets are buried beneath the sewing ring of the pro sthesis. Thus support is given at the suture site without directly exposing the pledget to the bloodstream. Perhaps this technique could help to avoid the development of the obstruct ing membrane. We would suggest restric ting the use of
The technique of buttressing valve sutures over felt pledgets to prevent them from cutting through friable annulus tissue has been a useful adjunct in valve surgery. This communication reports 2 cases in which fibrous tissue overgrew Dacron pledgets placed around the annulus. The consequent subvalvular membrane resulted in critical aort ic stenosis. This occurrence has been implicated as the cause of death of 1 patient. REFERENCES Allen, P., and Robertson, R.: Significance of Intermittent Regurgitation in Aortic Valve Pro stheses, 1. THORAC. CARDIOVASC. SURD. 54: 549, 1967. 2 Isom, O. W., Will iam s, C. D. , F alk , E. A., Gl assman, E., and Spen cer, F. C.: Long-Term Evalu at ion of C lo th-Covered Metal lic Ball Pro sthe ses, J . THORAC. CARDIOVASC. SURD. 64: 354, 1972. 3 Kastor, 1. A., Akba rian, M., Buckley, M. 1., Dinsmore, R. E., Sanders, C. A., Scann ell, J. G. , and A uste n, W. G.: Parav alvular Leaks and Hemolytic A nemia Following In sertion of Starr-Ed wards Aortic and Mitral Val ves, J. THORAC. CARDIOVASC. S URD . 56: 279, 1968. 4 MacVaugh, H., III, Jo yner, C. R., an d Johnson, J. : Unu sual Co mplica tions Du ring Mitral Valve Replacem ent in the Presence of Calcific ation of the Annulus, Ann. Thorac. Su rg, 11: 336 , 1971.
The Journal of
20
Weinstein et ai.
Thoracic and Cardiovascular Surgery
5 Spencer, F. c., Reed, G. E., Clauss, R. H., Tice, D. A, and Reppert, E. H.: Cloth-Covered Aortic and Mitral Valve Prostheses, J. THORAC. CARDIOVASC. SURG. 59: 92, 1970. 6 Weldon, C. S., Krause, A H., Parker, B. M., Clark, R. E., and Roper, C. L.: Clinical Recog-
nition and Surgical Management of Acute Disruption of the Mitral Valve, Ann. Surg. 197: 336, 1971. 7 Gago, 0., and Kirsh, M. M.: A New Technique for Cardiac Valve Replacement, Chest 61: 674, 1972.
G. Weinstein, M.D., A. J. Franzone, M.D., S. H. Stertzer, M.D., and E. Wallsh, M.D., New York, N. Y.
The attachment of a prosthetic heart valve to a friable, heavily calcified annulus is a persistent problem in the surgery of valvular heart disease. Separation of the prosthesis from portions of the annulus may lead to paravalvular insufficiency, severe hemolysis, and intractable myocardial failure.':" A current technique, first described by Weldon and co-workers, G utilizes reinforcing felt pledgets to prevent the sutures from cutting through a friable annulus. Although originally described for mitral valves, this method is now used for aortic and tricuspid valves as well.": 6 In this communication, we present 2 cases that illustrate the development of subvalvular aortic stenosis, a previously unreported complication of Dacron pledget use. Case report CASE 1. E. H., a 41-year-old woman with aortic stenosis and insufficiency secondary to rheumatic valvular disease, underwent aortic valve replacement in February, 1971. A No. 8 StarrEdwards (Model 2310) ball-valve prosthesis was inserted in the aortic annulus. Because of heavy calcification requiring extensive debridement, nine mattress sutures buttressed with Dacron felt
From Lenox Hill Hospital, New York, N. Y. 10021. Received for publication Dec. 7. t973.
pledgets on the ventricular surface of the aortic annulus were used to fix the valve in place. An acceptable systolic pressure gradient of 30 mm. Hg was present across the valve at the completion of the procedure. The patient made an uneventful recovery. On Dec. 21, 1971, the patient had an episode of supraventricular tachycardia with frequent ventricular premature contractions. She was successfully treated by direct-current cardioversion. On March 12, 1972, she was readmitted to the hospital for severe dyspnea and diaphoresis. At that time, the prosthetic valve sounds were normal. An aortic systolic ejection murmur present since the operation had increased in intensity during the postoperative period. Within hours, the patient became lethargic. She developed atrial fibrillation with a slow ventricular rate, followed by low output syndrome, ventricular tachycardia, and cardiac arrest. Postmortem examination revealed a subvalvular fibrous diaphragm with a narrowed orifice resulting from the ingrowth of fibrous tissue along the pledgets (Figs. 1 and 2). Death appeared to have resulted from the development of a critical degree of stenosis below the suture ring of the prosthetic aortic valve. CASE 2. N. P., a 65-year-old woman, had mitral and aortic valve replacement on Nov. 24, 1970, for rheumatic valvular disease. Size 4 and 8 Starr-Edwards (Models 6310 and 2310) were placed in the mitral and aortic positions, respectively. Because of heavy calcification in both areas, Dacron buttresses were employed circumferentially in the subannular area of each valve.
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Weinstein et al.
The Journal of Thoracic a nd Cardiovascular Surgery
Fig. 1. Postmortem view of aortic prosthesis viewed from the left ventricular surface. Fibrous ingrowth is apparent across the valve orifice. A, Prosthetic sewing ring . B, Cut edge of fibrous ring . C, Intact fibrous membrane. D, Prosthetic metal ball. E, Mitral leaflet. The postoperative course was complicated by a moderate basilar artery-brainstern syndrome and respiratory insufficiency, which were managed by tracheostomy and assisted ventilation. She was discharged 2 months after the operation in satisfactory condition. On April 23, 1972, she presented with progressive and per sistent fatigue, fever , anemia, and transient multiple neurologic defects suggestive of systemic embolization. Ph ysical examination revealed norm al prosthetic valve sounds and a Grade 2/6 systo lic ejection murmur over the aortic are a and left sternal border. These findings had not changed since the operation. The patient underwent an exploratory cardiotomy on April 25, 1972. The aortic valve was covered with an adherent, slimy material which extended across the struts and through the valve ring. A fibrou s ring and the enclo sed D acron pled gets were excised after mobilization of the valve. A No. 9 Starr-Edwards aortic prosthesis ( Model 2320) was replaced in the original site without the use of reinforcing pledgets. The mitral valve was normal by direct inspection, without evidence of a fibrous ring. The patient had an uneventful recovery. Microscopic examination of the valve revealed fragments of hyalinized connective tissue and thrombus. Cultures of the valve and fibrou s ring were sterile.
Discussion
The technique of buttressing valve sutures over Dacron pledgets to prevent dehiscence
has become a useful adjunct in valve surgery." Progressive stenosis has not been previously reported. The 2 cases described here illustrate the formation of a dense fibrous subvalvular membrane with consequent severe aortic stenosis. Examination of both patients revealed a loud systolic ejection murmur at the aortic area and left sternal border with normal prosthetic valve sounds . The first patient had a gradual and unexplained increase in the intensity of the murmur. Late developments included arrhythmia, low cardiac output, systemic embolization, fever, and anemia. Several factors appear to contribute to the development of the subvalvular membrane. Extensive injury secondary to debriding large amounts of calcium from the aortic annulus and adjacent areas may result in an exuberant fibroblastic response. The use of Dacron as pledget material may encourage a hyperplastic tissue reaction, despite the fact that Dacron has a history of extensive use without complications . Last, a smaIl valve, i.e., Starr-Edwards size 8 (Model 2310), in the aortic area could cause turbulence and lead to the deposition of blood elements, thereby enhancing the ring formation.
Volume 68 Number 1 July, 1974
Sub valvular stenosis of aortic prostheses
19
buttresses to specific sutures in weakened areas rather than random circumferential insertion. Because of its diminished fibroblastic response, Teflon is probably the material of choice. The buttresses should be small ( 10 by 3 mm.) and should be placed well under the residual annulus and outer edge of the valve sewing ring. In add ition, the No. 8 Starr -Edwards valve should be restricted to those patients in whom a significant postoperative gradient will not be created. In cases in which a small valve is needed, a tilting-disc prosthesis is preferable. Finally , the occurrence of subvalvular aortic stenosis secondary to the use of pledgets must be included in the differential diagnosis of late complications of aort ic valve replacements. Summary
Fig. 2. Close-up view of the specimen shown in Fig. I, with the pro sthe sis removed. A , Aortic commissures. B , Fibrous "a nnulus." C, Dac ron pledget. D, Cut edge of fibrou s membrane. E, In situ suture. F , Mitral leaflet.
The extensive removal of calcium from the aortic annulus in preparation for valve replacement is obligatory. The thinned and weakened annulus must be supported, or operative tears with resultant bleeding and late valvular disruption may occur. Gago and Kirsh - report ed 50 cases of valve replacement in which Dacron pledgets were used to avoid periprosthetic tears. In these cases, the pledgets were fixed on the aortic side of the valve annulus, After the prosthesis is tied in place, the pledgets are buried beneath the sewing ring of the pro sthesis. Thus support is given at the suture site without directly exposing the pledget to the bloodstream. Perhaps this technique could help to avoid the development of the obstruct ing membrane. We would suggest restric ting the use of
The technique of buttressing valve sutures over felt pledgets to prevent them from cutting through friable annulus tissue has been a useful adjunct in valve surgery. This communication reports 2 cases in which fibrous tissue overgrew Dacron pledgets placed around the annulus. The consequent subvalvular membrane resulted in critical aort ic stenosis. This occurrence has been implicated as the cause of death of 1 patient. REFERENCES Allen, P., and Robertson, R.: Significance of Intermittent Regurgitation in Aortic Valve Pro stheses, 1. THORAC. CARDIOVASC. SURD. 54: 549, 1967. 2 Isom, O. W., Will iam s, C. D. , F alk , E. A., Gl assman, E., and Spen cer, F. C.: Long-Term Evalu at ion of C lo th-Covered Metal lic Ball Pro sthe ses, J . THORAC. CARDIOVASC. SURD. 64: 354, 1972. 3 Kastor, 1. A., Akba rian, M., Buckley, M. 1., Dinsmore, R. E., Sanders, C. A., Scann ell, J. G. , and A uste n, W. G.: Parav alvular Leaks and Hemolytic A nemia Following In sertion of Starr-Ed wards Aortic and Mitral Val ves, J. THORAC. CARDIOVASC. S URD . 56: 279, 1968. 4 MacVaugh, H., III, Jo yner, C. R., an d Johnson, J. : Unu sual Co mplica tions Du ring Mitral Valve Replacem ent in the Presence of Calcific ation of the Annulus, Ann. Thorac. Su rg, 11: 336 , 1971.
The Journal of
20
Weinstein et ai.
Thoracic and Cardiovascular Surgery
5 Spencer, F. c., Reed, G. E., Clauss, R. H., Tice, D. A, and Reppert, E. H.: Cloth-Covered Aortic and Mitral Valve Prostheses, J. THORAC. CARDIOVASC. SURG. 59: 92, 1970. 6 Weldon, C. S., Krause, A H., Parker, B. M., Clark, R. E., and Roper, C. L.: Clinical Recog-
nition and Surgical Management of Acute Disruption of the Mitral Valve, Ann. Surg. 197: 336, 1971. 7 Gago, 0., and Kirsh, M. M.: A New Technique for Cardiac Valve Replacement, Chest 61: 674, 1972.