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Aortic complications after bicuspid aortic valve replacement: long-term results
Aortic Complications After Bicuspid Aortic Valve Replacement: Long-Term Results Claudio F. Russo, MD, Simone Mazzetti, MD, Andrea Garatti, MD, Elena Ribera, MD, Angela Milazzo, MD, Giuseppe Bruschi, Marco Lanfranconi, MD, Tiziano Colombo, MD, and Ettore Vitali, MD Division of Cardiovascular Surgery and Division of Cardiology, Echocardiography Service, Niguarda Hospital, Milan, Italy
Background. Bicuspid aortic valve (BAV) is a risk factor for aortic dissection and aneurysm. We studied patients with BAV and tricuspid aortic valve (TAV) to evaluate long-term changes in the ascending aorta after aortic valve replacement (AVR). Patients and Methods. One hundred consecutive patients were allocated into two groups according to the presence of BAV (group A, 50 patients) or TAV (group B, 50 patients). Mean age was 51 ⴞ 12 years in group A, and 50 ⴞ years 12 in group B. No patients had hypertension or Marfan’s syndrome. Until July 2001, mean follow-up was 234 ⴞ 47 months in group A and 241 ⴞ 43 months in group B. Results. Five patients (10%, CL 5.7 to 13.9) in group A suffered late acute aortic dissection. Acute aortic dissec-
tion (5 vs 0, p ⴝ 0.0001) and sudden death (7 vs 0, p ⴝ 0.0001) occurred more frequently in patients with BAV. All survivors were assessed by echocardiogram. The mean diameter of the ascending aorta was 48.4 mm in group A and 36.8 mm in group B. Three patients in group A were operated on because of ascending aorta aneurysm more than 6 cm in diameter. Conclusions. As a result of our experience, we recommend a policy of prophylactic replacement of even a seemingly normal and definitely a mildly enlarged ascending aorta in cases of BAV at the moment of AVR, and consideration of a similar approach for any other cardiac surgical procedure in patients with BAV. (Ann Thorac Surg 2002;74:S1773– 6) © 2002 by The Society of Thoracic Surgeons
B
body surface area (1.8 m2 in group A vs 1.75 m2 in group B), aortic valve disease (regurgitation, 9 patients vs 7 patients; stenosis, 21 patients vs 29 patients; mixed, 20 patients vs 14 patients, respectively in group A vs group B); type of surgery; period of observation; as well as prosthesis design. Twenty-one (42%) patients in group A and 23 (46%) in group B were in New York Heart Association (NYHA) class II. The remaining patients were in NYHA class III. No patient exhibited suggestive signs of Marfan’s disease; no one was suffering from chronic arterial hypertension or arrhythmia; no history of chronic cardiac failure was reported. The indication for surgery was based on the severity of aortic valve disease; preoperative measurement of the ascending aorta was not undertaken. The diagnosis of BAV was confirmed at surgery. Patients with annuloaortic ectasia were excluded. The ascending aorta diameter, surgically assessed, was reported as normal at the time of aortic valve surgery. In no instance were either abnormalities of the aortic root shape or fragility of the aortic wall described. Follow-up ended in July 2001. All survivors underwent clinical and echocardiographic assessment.
icuspid aortic valve (BAV) is the most frequent congenital lesion in adults [1]. Even in the absence of significant aortic valve disease, BAV is frequently associated with aortic root dilatation, annuloaortic ectasia, and aortic dissection [1, 2]. After aortic valve replacement (AVR), BAV is reported as a risk factor for late acute dissection and aneurysm of the ascending aorta [4 – 6]. To evaluate the risk of complications of the ascending aorta associated with BAV, we compared two groups of patients undergoing AVR: group A, with congenital BAV, and group B, with a tricuspid aortic valve (TAV).
Material and Methods Between January 1975 and December 1985, 50 consecutive patients with BAV underwent elective isolated AVR (group A). This group was compared with a control group of another 50 patients, who underwent elective isolated AVR for a diseased tricuspid valve during the same time period and in the same hospital (group B). The groups were homogeneous in terms of composition: age (51 ⫾ 2 years in group A and 50 ⫾ 2 years in group B); gender (male/female ratio of 35:15 in group A vs 41:9 in group B);
Definitions Presented at the Aortic Surgery Symposium VIII, May 2–3, 2002, New York, NY. Address reprint requests to Dr Russo, Division of Cardiovascular Surgery, Niguarda Hospital, Piazza Ospedale Maggiore 3, 20162 Milan, Italy; e-mail: [email protected].
© 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Sudden unexplained death was the designation for each case of sudden death of unknown cause. Acute aortic dissection or rupture were classified as acute aortic syndrome. Acute aortic syndrome and aneurysm of the ascending aorta were classified as aortic events. 0003-4975/02/$22.00 PII S0003-4975(02)04261-3
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Ann Thorac Surg 2002;74:S1773– 6
Fig 1. Kaplan-Meier actuarial survival estimates for A group (BAV) and B group (control). Late aortic dissection and sudden death accounted for a higher late mortality in group A. Open circles ⫽ bicuspid; solid circles ⫽ control. (BAV ⫽ bicuspid aortic valve; pts ⫽ patients.)
Results In group A, mean follow-up was 234 ⫾ 48 months (142 to 308); 34 (68%, CL 60.0 to 73.2) patients died. Five (10%, CL 5.7 to 13.8) patients died of cardiac causes (two myocardial infarctions, two cases of endocarditis, one ventricular fibrillation). Five (10%, CL 5.7 to 13.8) patients died because of acute aortic syndrome. Sudden unexplained death was reported in 7 patients (14%, CL 8.9 to 18.5). No autopsy reports were available. Three patients (6%, CL 2.7 to 9.0) were reoperated on for aneurysm of the ascending aorta more than 6 cm in diameter, 36, 120, and 264 months after the first operation, respectively. The last one died on the third postoperative day because of a perioperative stroke. In group B, mean follow-up was 241 ⫾ 43.6 months (193.3 to 311.8); 24 (48%, CL 40.06 to 54.47) late deaths occurred. Eight (16%, CL 10.63 to 20.73) patients died of cardiac causes (three congestive heart failures, three reoperations for valve prosthesis dysfunction, two acute myocardial infarctions). No patients in group B died because of acute aortic syndrome, and no sudden unexplained deaths were reported. Sudden unexplained death and acute aortic syndrome accounted for a higher mortality rate in group A than in group B (p ⫽ 0.047; Fig 1). A greater incidence of sudden death and aortic events occurred in the BAV group compared with the control group (15 vs 0, p ⬍ 0.0001). A cardiac-related event survival curve is depicted in Figure
2. The distribution of deaths over time is shown in Figure 3. No patient in group B suffered aortic events. Due to small cohorts, we could not identify any risk factor for aortic event or sudden unexplained death in group A among the following variables using logistic regression analysis: age, gender, aortic valve disease, kind of prosthesis, size of prosthesis, renal insufficiency, diabetes, preoperative and postoperative NYHA class, or postoperative hypertension. All survivors (16 in group A and 26 in group B) underwent echocardiographic assessment of the ascending aorta. The mean sizes of the aortic root segments were statistically larger in BAV patients (p ⬍ 0.05): sinus of Valsalva diameter was 39.25 versus 32.9 mm, and ascending aorta diameter was 48.4 versus 36.7 mm, respectively.
Comment A bicuspid aortic valve is often associated with pathology of the ascending aorta: coarctation, aneurysm, and dissection [1, 2, 9]. These complications are in some way the result of intrinsic aortic tissue weakening [4, 10]. The association between BAV and aortic cystic medial necrosis has also been reported [3, 11], suggesting a defect common to aortic valve and vessel development. The failure of the Ross procedure in patients with BAV [12] tends to confirm the existence of a congenital defect
Ann Thorac Surg 2002;74:S1773– 6
AORTIC SURGERY SYMPOSIUM VIII RUSSO ET AL COMPLICATIONS AFTER BICUSPID AORTIC VALVE REPLACEMENT
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Fig 2. Cardiac-related event survival curve estimates for group A (BAV) and group B (control). The cardiac events include cardiac death, sudden unexplained death, and aortic acute syndrome deaths, and again account for a higher mortality in group A. Open circles ⫽ bicuspid; solid circles ⫽ control. (BAV ⫽ bicuspid aortic valve; pts ⫽ patients.)
common to the structures that originate from neural crest cells. BAV itself is reported as a risk factor for aortic dissection after AVR. [5] Our study confirms the higher risk of late ascending aorta aneurysm or dissection in patients with BAV, and
reinforces the importance of appropriate timing of ascending aorta replacement in case of AVR or other cardiac procedures in these patients. Our data show a greater incidence of sudden death and aortic events in the BAV group. All patients had a seemingly normal Fig 3. Distribution of causes of death during late follow-up in group A (BAV). Most of the acute aortic syndromes and sudden deaths occurred more than 15 years after AVR. Late aortic dissections cannot be considered an iatrogenic complication of valve replacement. Solid bars ⫽ cardiac deaths; open bars ⫽ acute aortic syndromes; striped bars ⫽ sudden unexplained deaths; crosshatched bars ⫽ other causes. (BAV ⫽ bicuspid aortic valve; AVR ⫽ aortic valve replacement.)
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ascending aorta at surgery. The occurrence of ascending aortic alterations during follow-up could not be predicted at the time of the first operation; it was independent of the type of aortic valve disease and of the ascending aorta diameter. The real incidence of late acute aortic complications in the BAV group may be even higher than it appears from this study, because sudden unexplained death occurred in 7 patients in group A and in no patients in group B. We cannot be sure that all sudden deaths are linked to acute pathology of the ascending aorta. However, considering that none of these patients was suffering from severe arrhythmias or chronic heart failure, at least some of these deaths could be related to acute aortic syndrome. Furthermore, most of the sudden unexplained deaths and acute aortic syndrome both occurred 10 to 15 years after AVR (Fig 2). This suggests that deaths due to acute aortic syndrome (which may include some of the sudden unexplained deaths) should not be considered an iatrogenic complication of the primary surgery, but rather related to intrinsic aortic wall weakness in patients with BAV. Echocardiographic follow-up confirmed significant proximal aorta dilation in the BAV group compared with the tricuspid group. The ascending aorta diameter was significantly larger in pts with BAV; 3 of the patients with BAV underwent reoperation for ascending aortic aneurysm. In our experience, all patients who experienced acute aortic syndrome during follow-up died. However, reoperations for acute aortic dissection or ascending aorta aneurysm after AVR have very high perioperative mortality and morbidity. [6, 7, 13] The patient with BAV seems to have a severe alteration of the aortic wall, which is potentially capable of evolving into acute aortic pathology or progressive dilation of the ascending aorta, independent of valve surgery [9 –12]. Nowadays, in our surgical practice, no diagnostic test exists that enables the prediction a priori of which patients with BAV will develop ascending aorta pathology. Stricter echocardiographic follow-up for these patients is encouraged in order to proceed to elective surgery in the case of aneurysms [14], but, in our experience, acute aortic complications could not be predicted on the basis of routine clinical and instrumental monitoring. Acute aortic syndrome occurred in 5 patients in the BAV group. In these patients, the diameter of the aorta was reported as normal at echocardiographic follow-up. Therefore, we suggest prophylactic replacement of the ascending aorta at the time of initial cardiac surgery independent of the size of the aorta, particularly in younger people. This aggressive approach is justified by the inability to predict aortic dissection, which can occur even when the ascending aorta sizes are still minimally dilated or even normal at the time of valve replacement. The risk of elective primary combined aortic valve and ascending aorta replacement is similar to that of isolated AVR, but it is consistently lower than the risk of elective or, even worse, emergency reoperation for ascending aorta pathology [6 – 8]. In patients with BAV and a normal ascending aorta, the simple replacement of the supra-
Ann Thorac Surg 2002;74:S1773– 6
coronary ascending aorta during AVR should not increase the surgical risk [7], preventing late aortic dissection. However, in younger patients, a more radical approach could be justified. In these cases, a complete aortic root replacement with a valved composite graft is probably the best treatment. On the other hand, in older patients, simple replacement of the ascending aorta above the sinuses may be considered adequate. This approach should also be considered at the time of other kinds of cardiac surgical procedures, and is justified in order to prevent devastating complications related to ascending aorta aneurysm and dissection. In any case, BAV patients should be maintained under strict surveillance, with echocardiography every 6 months and computed tomography scan once a year, to monitor the changes over time of the ascending aorta. Furthermore, we reiterate the importance of anticipatory surgery for dilatation of the ascending aorta in patients with bicuspid aortic valves compared with patients with tricuspid aortic valves.
References 1. Keane MG, Wingers SE, Plappert T, et al. Bicuspid aortic valves are associated with aortic dilatation out of proportion to coexistent valvular lesion. Circulation 2000;102(Suppl III): 35–39. 2. Nistri S, Sorbo MD, Martin M, et al. Aortic root dilatation in young men with normally functioning bicuspid aortic valve. Heart 1999;82:19 –22. 3. McKusick. Association of congenital bicuspid aortic valve and Erdheim’s cystic medial necrosis. Lancet 1972;I:1026 –7. 4. Bonderman D, Gharehbaghi-Schnell E, Wolleneck G. Mechanism underlying aortic dilatation in congenital aortic valve malformation. Circulation 1999;16:2138 – 43. 5. Pieters FA, Widdershoven JW, Gerardy AC, et al. Risk of aortic dissection after aortic valve replacement. Am J Cardiol 1993;72:1043–7. 6. Prenger K, Pieters F, Cheriex E, et al. Aortic dissection after aortic valve replacement: incidence and consequences for strategy. J Card Surg 1994;9:495–9. 7. Yun KL, Miller DC, Fann J, et al. Compositive valve graft versus separate aortic valve and ascending aorta replacement: is there still a role for the separate procedure? Circulation 1993;96(Suppl II):368 –75. 8. Ergin MA, Spielvogel D, Apaydin A. Surgical treatment of dilated ascending aorta: when and how? Ann Thorac Surg 1998;66:629 –34. 9. Braverman AC. Bicuspid aortic valve and associated aortic wall abnormalities. Curr Opin Cardiol 1996;11:501–3. 10. Parai JL, Masters RG, et al. Aortic medial changes associated with bicuspid aortic valve: myth or reality? Can J Cardiol 1999;15:1233–8. 11. Schlatmann TJM, Becker AE. Pathogesis of dissection aneurysm of aorta: comparative histopathologic study of significance of medical change. Am J Cardiol 1977;39:21–6. 12. De Sa M, Moshkovitz Y, Butani J, David TE. Histological abnormalities of the ascending aorta and pulmonary trunk in patient with bicuspid aortic valve disease: clinical relevance to the Ross procedures. J Thoracic Cardiovascular Surg 1999;118:588 –94. 13. Burks JM, Ille RW, Keating E, et al. Ascending aneurysm and dissection in young adults with bicuspid aortic valve: implication for echocardiographic surveillance. Clin Cardiol 1998; 21:439 –43. 14. Dougenis D, Dayli BB, Kouchoukos NT. Reoperation on aortic root and ascending aorta. Ann Thorac Surg 1997;64: 986 –92.
Background. Bicuspid aortic valve (BAV) is a risk factor for aortic dissection and aneurysm. We studied patients with BAV and tricuspid aortic valve (TAV) to evaluate long-term changes in the ascending aorta after aortic valve replacement (AVR). Patients and Methods. One hundred consecutive patients were allocated into two groups according to the presence of BAV (group A, 50 patients) or TAV (group B, 50 patients). Mean age was 51 ⴞ 12 years in group A, and 50 ⴞ years 12 in group B. No patients had hypertension or Marfan’s syndrome. Until July 2001, mean follow-up was 234 ⴞ 47 months in group A and 241 ⴞ 43 months in group B. Results. Five patients (10%, CL 5.7 to 13.9) in group A suffered late acute aortic dissection. Acute aortic dissec-
tion (5 vs 0, p ⴝ 0.0001) and sudden death (7 vs 0, p ⴝ 0.0001) occurred more frequently in patients with BAV. All survivors were assessed by echocardiogram. The mean diameter of the ascending aorta was 48.4 mm in group A and 36.8 mm in group B. Three patients in group A were operated on because of ascending aorta aneurysm more than 6 cm in diameter. Conclusions. As a result of our experience, we recommend a policy of prophylactic replacement of even a seemingly normal and definitely a mildly enlarged ascending aorta in cases of BAV at the moment of AVR, and consideration of a similar approach for any other cardiac surgical procedure in patients with BAV. (Ann Thorac Surg 2002;74:S1773– 6) © 2002 by The Society of Thoracic Surgeons
B
body surface area (1.8 m2 in group A vs 1.75 m2 in group B), aortic valve disease (regurgitation, 9 patients vs 7 patients; stenosis, 21 patients vs 29 patients; mixed, 20 patients vs 14 patients, respectively in group A vs group B); type of surgery; period of observation; as well as prosthesis design. Twenty-one (42%) patients in group A and 23 (46%) in group B were in New York Heart Association (NYHA) class II. The remaining patients were in NYHA class III. No patient exhibited suggestive signs of Marfan’s disease; no one was suffering from chronic arterial hypertension or arrhythmia; no history of chronic cardiac failure was reported. The indication for surgery was based on the severity of aortic valve disease; preoperative measurement of the ascending aorta was not undertaken. The diagnosis of BAV was confirmed at surgery. Patients with annuloaortic ectasia were excluded. The ascending aorta diameter, surgically assessed, was reported as normal at the time of aortic valve surgery. In no instance were either abnormalities of the aortic root shape or fragility of the aortic wall described. Follow-up ended in July 2001. All survivors underwent clinical and echocardiographic assessment.
icuspid aortic valve (BAV) is the most frequent congenital lesion in adults [1]. Even in the absence of significant aortic valve disease, BAV is frequently associated with aortic root dilatation, annuloaortic ectasia, and aortic dissection [1, 2]. After aortic valve replacement (AVR), BAV is reported as a risk factor for late acute dissection and aneurysm of the ascending aorta [4 – 6]. To evaluate the risk of complications of the ascending aorta associated with BAV, we compared two groups of patients undergoing AVR: group A, with congenital BAV, and group B, with a tricuspid aortic valve (TAV).
Material and Methods Between January 1975 and December 1985, 50 consecutive patients with BAV underwent elective isolated AVR (group A). This group was compared with a control group of another 50 patients, who underwent elective isolated AVR for a diseased tricuspid valve during the same time period and in the same hospital (group B). The groups were homogeneous in terms of composition: age (51 ⫾ 2 years in group A and 50 ⫾ 2 years in group B); gender (male/female ratio of 35:15 in group A vs 41:9 in group B);
Definitions Presented at the Aortic Surgery Symposium VIII, May 2–3, 2002, New York, NY. Address reprint requests to Dr Russo, Division of Cardiovascular Surgery, Niguarda Hospital, Piazza Ospedale Maggiore 3, 20162 Milan, Italy; e-mail: [email protected].
© 2002 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Sudden unexplained death was the designation for each case of sudden death of unknown cause. Acute aortic dissection or rupture were classified as acute aortic syndrome. Acute aortic syndrome and aneurysm of the ascending aorta were classified as aortic events. 0003-4975/02/$22.00 PII S0003-4975(02)04261-3
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AORTIC SURGERY SYMPOSIUM VIII RUSSO ET AL COMPLICATIONS AFTER BICUSPID AORTIC VALVE REPLACEMENT
Ann Thorac Surg 2002;74:S1773– 6
Fig 1. Kaplan-Meier actuarial survival estimates for A group (BAV) and B group (control). Late aortic dissection and sudden death accounted for a higher late mortality in group A. Open circles ⫽ bicuspid; solid circles ⫽ control. (BAV ⫽ bicuspid aortic valve; pts ⫽ patients.)
Results In group A, mean follow-up was 234 ⫾ 48 months (142 to 308); 34 (68%, CL 60.0 to 73.2) patients died. Five (10%, CL 5.7 to 13.8) patients died of cardiac causes (two myocardial infarctions, two cases of endocarditis, one ventricular fibrillation). Five (10%, CL 5.7 to 13.8) patients died because of acute aortic syndrome. Sudden unexplained death was reported in 7 patients (14%, CL 8.9 to 18.5). No autopsy reports were available. Three patients (6%, CL 2.7 to 9.0) were reoperated on for aneurysm of the ascending aorta more than 6 cm in diameter, 36, 120, and 264 months after the first operation, respectively. The last one died on the third postoperative day because of a perioperative stroke. In group B, mean follow-up was 241 ⫾ 43.6 months (193.3 to 311.8); 24 (48%, CL 40.06 to 54.47) late deaths occurred. Eight (16%, CL 10.63 to 20.73) patients died of cardiac causes (three congestive heart failures, three reoperations for valve prosthesis dysfunction, two acute myocardial infarctions). No patients in group B died because of acute aortic syndrome, and no sudden unexplained deaths were reported. Sudden unexplained death and acute aortic syndrome accounted for a higher mortality rate in group A than in group B (p ⫽ 0.047; Fig 1). A greater incidence of sudden death and aortic events occurred in the BAV group compared with the control group (15 vs 0, p ⬍ 0.0001). A cardiac-related event survival curve is depicted in Figure
2. The distribution of deaths over time is shown in Figure 3. No patient in group B suffered aortic events. Due to small cohorts, we could not identify any risk factor for aortic event or sudden unexplained death in group A among the following variables using logistic regression analysis: age, gender, aortic valve disease, kind of prosthesis, size of prosthesis, renal insufficiency, diabetes, preoperative and postoperative NYHA class, or postoperative hypertension. All survivors (16 in group A and 26 in group B) underwent echocardiographic assessment of the ascending aorta. The mean sizes of the aortic root segments were statistically larger in BAV patients (p ⬍ 0.05): sinus of Valsalva diameter was 39.25 versus 32.9 mm, and ascending aorta diameter was 48.4 versus 36.7 mm, respectively.
Comment A bicuspid aortic valve is often associated with pathology of the ascending aorta: coarctation, aneurysm, and dissection [1, 2, 9]. These complications are in some way the result of intrinsic aortic tissue weakening [4, 10]. The association between BAV and aortic cystic medial necrosis has also been reported [3, 11], suggesting a defect common to aortic valve and vessel development. The failure of the Ross procedure in patients with BAV [12] tends to confirm the existence of a congenital defect
Ann Thorac Surg 2002;74:S1773– 6
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Fig 2. Cardiac-related event survival curve estimates for group A (BAV) and group B (control). The cardiac events include cardiac death, sudden unexplained death, and aortic acute syndrome deaths, and again account for a higher mortality in group A. Open circles ⫽ bicuspid; solid circles ⫽ control. (BAV ⫽ bicuspid aortic valve; pts ⫽ patients.)
common to the structures that originate from neural crest cells. BAV itself is reported as a risk factor for aortic dissection after AVR. [5] Our study confirms the higher risk of late ascending aorta aneurysm or dissection in patients with BAV, and
reinforces the importance of appropriate timing of ascending aorta replacement in case of AVR or other cardiac procedures in these patients. Our data show a greater incidence of sudden death and aortic events in the BAV group. All patients had a seemingly normal Fig 3. Distribution of causes of death during late follow-up in group A (BAV). Most of the acute aortic syndromes and sudden deaths occurred more than 15 years after AVR. Late aortic dissections cannot be considered an iatrogenic complication of valve replacement. Solid bars ⫽ cardiac deaths; open bars ⫽ acute aortic syndromes; striped bars ⫽ sudden unexplained deaths; crosshatched bars ⫽ other causes. (BAV ⫽ bicuspid aortic valve; AVR ⫽ aortic valve replacement.)
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ascending aorta at surgery. The occurrence of ascending aortic alterations during follow-up could not be predicted at the time of the first operation; it was independent of the type of aortic valve disease and of the ascending aorta diameter. The real incidence of late acute aortic complications in the BAV group may be even higher than it appears from this study, because sudden unexplained death occurred in 7 patients in group A and in no patients in group B. We cannot be sure that all sudden deaths are linked to acute pathology of the ascending aorta. However, considering that none of these patients was suffering from severe arrhythmias or chronic heart failure, at least some of these deaths could be related to acute aortic syndrome. Furthermore, most of the sudden unexplained deaths and acute aortic syndrome both occurred 10 to 15 years after AVR (Fig 2). This suggests that deaths due to acute aortic syndrome (which may include some of the sudden unexplained deaths) should not be considered an iatrogenic complication of the primary surgery, but rather related to intrinsic aortic wall weakness in patients with BAV. Echocardiographic follow-up confirmed significant proximal aorta dilation in the BAV group compared with the tricuspid group. The ascending aorta diameter was significantly larger in pts with BAV; 3 of the patients with BAV underwent reoperation for ascending aortic aneurysm. In our experience, all patients who experienced acute aortic syndrome during follow-up died. However, reoperations for acute aortic dissection or ascending aorta aneurysm after AVR have very high perioperative mortality and morbidity. [6, 7, 13] The patient with BAV seems to have a severe alteration of the aortic wall, which is potentially capable of evolving into acute aortic pathology or progressive dilation of the ascending aorta, independent of valve surgery [9 –12]. Nowadays, in our surgical practice, no diagnostic test exists that enables the prediction a priori of which patients with BAV will develop ascending aorta pathology. Stricter echocardiographic follow-up for these patients is encouraged in order to proceed to elective surgery in the case of aneurysms [14], but, in our experience, acute aortic complications could not be predicted on the basis of routine clinical and instrumental monitoring. Acute aortic syndrome occurred in 5 patients in the BAV group. In these patients, the diameter of the aorta was reported as normal at echocardiographic follow-up. Therefore, we suggest prophylactic replacement of the ascending aorta at the time of initial cardiac surgery independent of the size of the aorta, particularly in younger people. This aggressive approach is justified by the inability to predict aortic dissection, which can occur even when the ascending aorta sizes are still minimally dilated or even normal at the time of valve replacement. The risk of elective primary combined aortic valve and ascending aorta replacement is similar to that of isolated AVR, but it is consistently lower than the risk of elective or, even worse, emergency reoperation for ascending aorta pathology [6 – 8]. In patients with BAV and a normal ascending aorta, the simple replacement of the supra-
Ann Thorac Surg 2002;74:S1773– 6
coronary ascending aorta during AVR should not increase the surgical risk [7], preventing late aortic dissection. However, in younger patients, a more radical approach could be justified. In these cases, a complete aortic root replacement with a valved composite graft is probably the best treatment. On the other hand, in older patients, simple replacement of the ascending aorta above the sinuses may be considered adequate. This approach should also be considered at the time of other kinds of cardiac surgical procedures, and is justified in order to prevent devastating complications related to ascending aorta aneurysm and dissection. In any case, BAV patients should be maintained under strict surveillance, with echocardiography every 6 months and computed tomography scan once a year, to monitor the changes over time of the ascending aorta. Furthermore, we reiterate the importance of anticipatory surgery for dilatation of the ascending aorta in patients with bicuspid aortic valves compared with patients with tricuspid aortic valves.
References 1. Keane MG, Wingers SE, Plappert T, et al. Bicuspid aortic valves are associated with aortic dilatation out of proportion to coexistent valvular lesion. Circulation 2000;102(Suppl III): 35–39. 2. Nistri S, Sorbo MD, Martin M, et al. Aortic root dilatation in young men with normally functioning bicuspid aortic valve. Heart 1999;82:19 –22. 3. McKusick. Association of congenital bicuspid aortic valve and Erdheim’s cystic medial necrosis. Lancet 1972;I:1026 –7. 4. Bonderman D, Gharehbaghi-Schnell E, Wolleneck G. Mechanism underlying aortic dilatation in congenital aortic valve malformation. Circulation 1999;16:2138 – 43. 5. Pieters FA, Widdershoven JW, Gerardy AC, et al. Risk of aortic dissection after aortic valve replacement. Am J Cardiol 1993;72:1043–7. 6. Prenger K, Pieters F, Cheriex E, et al. Aortic dissection after aortic valve replacement: incidence and consequences for strategy. J Card Surg 1994;9:495–9. 7. Yun KL, Miller DC, Fann J, et al. Compositive valve graft versus separate aortic valve and ascending aorta replacement: is there still a role for the separate procedure? Circulation 1993;96(Suppl II):368 –75. 8. Ergin MA, Spielvogel D, Apaydin A. Surgical treatment of dilated ascending aorta: when and how? Ann Thorac Surg 1998;66:629 –34. 9. Braverman AC. Bicuspid aortic valve and associated aortic wall abnormalities. Curr Opin Cardiol 1996;11:501–3. 10. Parai JL, Masters RG, et al. Aortic medial changes associated with bicuspid aortic valve: myth or reality? Can J Cardiol 1999;15:1233–8. 11. Schlatmann TJM, Becker AE. Pathogesis of dissection aneurysm of aorta: comparative histopathologic study of significance of medical change. Am J Cardiol 1977;39:21–6. 12. De Sa M, Moshkovitz Y, Butani J, David TE. Histological abnormalities of the ascending aorta and pulmonary trunk in patient with bicuspid aortic valve disease: clinical relevance to the Ross procedures. J Thoracic Cardiovascular Surg 1999;118:588 –94. 13. Burks JM, Ille RW, Keating E, et al. Ascending aneurysm and dissection in young adults with bicuspid aortic valve: implication for echocardiographic surveillance. Clin Cardiol 1998; 21:439 –43. 14. Dougenis D, Dayli BB, Kouchoukos NT. Reoperation on aortic root and ascending aorta. Ann Thorac Surg 1997;64: 986 –92.