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Konno procedure for critical aortic stenosis in infancy
Ross/Konno in Infancy
Procedure
for Critical
Aortic
Stenosis
John H. Calhoon, MD, and Joe W. R. Bolton, MD Division of Cardiothoracic
Surger!,
Lniversitv
of Texas Health Science Center at San Antonio,
San Antonio,
Texas
Although the Ross procedure has been applied successfully to the pediatric age group, it may have its ideal application in the selected infant with critical aortic stenosis and complex left ventricular outflow tract obstruction with adequate ventricular function and size. Two neonates presented with critical aortic stenosis and
complex left ventricular outflow tract obstructiou, and a combined Ross/Konno procedure was performed successfully. These cases are presented along with a discussion of this topic.
P
discharged to home after several weeks. Improvement continued since discharge, and his most recent echocardiogram done at 23 months of age showed sinus rhythm and a normally functioning neo-aortic valve with no regurgitation, mild mitral valve regurgitation with associated mild-to-moderate pulmonary hypertension, and trace tricuspid regurgitation. The left ventricular contractility is normal with a shortening fraction of 0.40. The echocardiogram suggests true growth consistent with cardiac dimensions, with the autograft measuring 9 to 70 mm at implantation and now 12 to 13 mm in diameter (Figs 7, 2). His weight has increased from 4.0 kg at birth to 10 kg, and he remains in the 25th percentile for weight and height.
alliation of infants with critical aortic stenosis continues to be a challenge for those cardiologists and cardiac surgeons caring for such children. However, when this problem is compounded by associated complex left ventricular outflow tract obstruction, the results have been even less satisfying. If not amenable to valvotomy, the alternatives for a trzo-ventricle repair include cardiac transplantation, aortoventriculoplasty (ie, Konno procedure) with placement of a mechanical prosthesis or allograft, or insertion of a left ventricular-aortic conduit. Some infants have required conversion to a singlrventricle repair with a Norwood procedure when the left ventricular outflow tract obstruction was severe.
Case Reports
(Ann Tkorac Surg 1995;6O:S597-9)
has
Patient 2 Patient 1 presented to the University Hospital in San Antonio on day 1 of life with congestive heart failure requiring intubation and administration of prostaglandin E,. An echocardiogram revealed severe congenital aortic stenosis with a 4-mm aortic annulus and a tremendouslv dysplastic unicusp-appearing aortic valve. There M a\ severe mitral regurgitation and a decreased left ventricular ejection fraction. It was thought, however, that the left ventricular volume was adequate to support the systemic circulation. After discussions with the parents, we resuscitated the child and took him to the operating room, where a pulmonarv autograft aortic root replacement was performed along with enlargement of the left ventricular outflow tract by a Konno procedure. The right ventricular outflow tract \j’as reconstructed with a l-l-mm aortic tiomograft. Postoperatively, there was poor left \rcntricular compliante associated with moderate mitral and tricuspid regurgitation. This gradually improved and the child was
Patient 2 was transferred to The University Hospital in Antonio on day 6 of life with an echocardiogram that showed critical aortic annular stenosis with a severely dvsplastic aortic valve, moderate mitral regurgitation, and diminished left ventricular function. After multidisciplinarv discussions we thought that an infant Ross procedure might afford the child the best option for normal left ventricular outflow growth and long-term benefit. The child was therefore taken to the operating room where he underwent a Ross pulmonary autograft aortic valve replacement with a Konno left ventricular outflow tract enlargement and right ventricular outflow tract reconstruction with a 13-mm pulmonary homograft. The postoperative course was complicated only by seiTures, which were easily controlled with phenobarbital. lie was discharged to home receiving only furosemide and was doing well 5 months postoperatively. His weight had increased from 3.3 to 4.4 kg. An echocardiogram performed at that time showed a normal neo-aortic valve and left ventricular outflow tract. The coronary arteries and heart chambers were normal, and there was only mild tnitral regurgitation. San
0003-4975/95/$9.50 SSDI 0003-4975(95)00816-O
Ann Thorac Surg 1995;60:5597-9
Comment The problem of complt’x nt~onatal aortic \.al\c htcxnohi\ can be challenging. In the major-it\. ot cams of isolated aortic valve stenosis palliation nl~~~ be accomplished b\ balloon dilation of the stenotic aoitic valve. This usualI; offers good short-term and internlt~diate-terlii rtahult\ However, if the valvular +teno& i\ complicated by J severelv dysplastic \.alve (\+.hich ma\ also be incomptatent), annular stenosis, sub\~al\~ular \Gnosib, or hupra\,,ilvular outflow tract stenosis, the abilit\ to attain a sati\factory result with balloon dilation i\ unlikeI\ 111. In addition, the likelihood of a Gmple ~~pc~rati\,t~ solutic\n in these situations is poor. The evolution ot the SLII-~I~-,I~ optlcln\ tot- tht, treatment of coniplt~w neonatal .Iortic’ \,JI\ t’ stc)no\l\ has includt,d no therapv, left ~cntricular to aorta \ al\td conduits, rlorto~entriculoplaitv tie, Kc~iliic~ procedure) to d~~o~ii~ilc~date allograft or mc\chanic,ll vdI\ ~9rc~plact~mcnt, nconat.ll cardiac transyl,lnt,lticln, Clll~i <‘oII\ kll-5ioli to single-vtbntrlcle phvsiolog\r through a Yor\~t~~~d I~roct~dul<‘. L ntclrtu
nately, each of these options is far from ideal and has resulted in either limited success or significant morbidity. Although the option of no treatment is occasionally correct, we believe this should be reserved for those infants who have other associated congenital defects that will result in death in and of themselves. Likewise, the conversion to a single-ventricle physiology through the use of the Norwood procedure should be reserved for those neonates whose ventricular size is not capable of supporting the systemic circulation. On the other hand, cardiac transplantation is primarily limited by the availability of suitable donor hearts. The morbidity and expense of supporting these neonates until an organ can be located must be considered. There also remains the long-term complications of immunosuppression and rejection after transplantation. The use of left ventricular aortic conduits for the intermediate palliation of complex left ventricular outflow tract obstruction has been reported in the pediatric age group. Frommelt and co-workers (21 reported their experience of using this technique in 20 pediatric patients and concluded that this may be useful in the palliation of selected patients as a staging procedure. Unfortunately, both of the early deaths in this series occurred in infants less than 2 months of age. Excellent relief of left ventricular outflow tract obstruction was obtained using left ventricular to aortic conduits in a series reported by Di Donato and colleagues [3]. Again, however, there was a high incidence of late complications requiring reoperation (7 of 9 survivors), and all 3 patients less than 2 years old had fibroelastosis and died. T‘he next step in the evolution of treatment of complex congenital left ventricular outflow tract obstruction in\;olved root-enlarging procedures to accommodate allograft and mechanical valve prostheses. After a review of their experience with left ventricle to aorta conduits Di Donato and colleagues [3] report that they prefer aortoventriculoplasty and placement of a nontissue valve in the natural subaortic position. However, even with the availability of smaller mechanical valves, there is a very limited role for mechanical valve placement in the neoIlate.
IlrKowen and associates [41 also reported on the use of extended aortic root replacement with associated aortoventriculoplasty in 3 patients. This group chose to use cryopreserved allograft valves and had no mortality, limited morbidity, and good functional results. The youngest patient in this report was 4% years old. A \imilar good experience with the use of this technique LVZ reported by Frommelt and associates [5]. In lYh7, Ross [6] first described the use of a pulmonary \-alve autograft to replace the aortic valve, and even as earlv as 7985, while options for the treatment of neonatal aortic valve stenosis were being explored, Robles and associates [7] working with Ross reported on 202 autologous pulmonary valve transplants for aortic valve replacement in adults and children. They concluded that “the long term performance of a pulmonary autograft inserted for aortic valve disease is superior to any other
Ann Thorai 5urg lY95;6O:S597-Y
valve substitute and that the operation offers an almost ideal means of aortic valve replacement in appropriate patients.” The youngest patient in that series was 9 years old, but it was noted that there had been “no incident of embolism and no evidence of calcification” in 14 vears of follow-up. More recently, in 1993, Kumar and colleagues [H] reported on 45 patients with a mean age of 77 years who underwent a Ross procedure for rheumatic heart disease. Although there was only a s-year follow-up, there were no early or late deaths and only 1 patient required reoperation at 2 years for a regurgitant pulmonary autograft. They concluded that pulmonary autograft transplantation to the aortic root may offer a near-permanent solution for the young rheumatic population with valve disease. The technique of ventriculoplasty to accommodate allograft placement in the younger age group has been well described by Clark 191. It is the use of this technique that allows insertion of the larger pulmonary autograft root into the stenotic left ventricular outflow tract. In addition to the forementioned techniques, research by others has contributed to our understanding of differences in pulmonary and aortic allograft behavior. Furthermore, studies have shown that incorporation of a live autograft allows for growth, and technical advancements have revealed that the ideal placement of the neo-aortic roots is intraannular. Each of these advancements has been made possible through the refinements of cardiopulmonary bypass techniques allowing for safe conduct of complex congenital cardiac repairs on neonates. Thus, building on this vast legacy, the next logical step in the evolution of the treatment of this condition was embarked upon. There are numerous advantages to a combined ROSS/ Konno procedure in the select group of neonates with complicated aortic valve stenosis and left ventricular outflow tract obstruction. The tissue valve avoids the problems with sizing, thrombosis, and anticoagulation as compared with a mechanical prosthesis. By using the pulmonary root there is identical design and placcment with respect to the native aortic root. Furthermore, the use of the pulmonary autograft has shown no immunologic rejection and no tissue decay, requires no supporting stent, and has shown true growth potential a\ compared with other tissue valves or cryopreserved allografts. There is also the theoretic advantage of improved longevitv and decreased calcification when the cryopreserved allograft is placed in the lower pressure pilmonary outflow tract [l, lo]. The procedure is not without its disadvantages, however. At the onset, the ability of the systemic ventricle to support the circulation must be ensured and the native pulmonary valve must be normal. The ventriculoplast! carries the risk of heart block, and there are immediate, intermediate and long-term problems attendant to mobilization and reimplantation of the coronary artcric5.
( \5 I Ar\t
DA FtSTSCHRIFT ROSSIKOXNO
(-AL tiOON PROCEDURE
AND BOLTON IN IA’FANCY
s599
The autotransplant itself converts a single-valve replacement into a double-valve replacement. Finally, the relative difficulty of the operation in an already acutely ill neonate represents a challenge in and of itself. Because of the very small aortic annulus and severely dysplastic aortic valve presented in these 2 cases it was thought that the possibility of successful valvotomy using a balloon or open technique was remote. The options of no intervention, cardiac transplantation, and Norwood procedure were entertained but rejected. These critically ill children were salvageable due to adequate left ventricular volume and function to support a two-ventricle repair. Thus, pulmonary valve autotransplantation with aortoventriculoplasty and right ventricular outflow tract reconstruction using cryopreserved allograft was performed. Subsequently, there has been presumed growth of the neo-aortic valve and root with improved ventricular function over 2 years without need for further intervention. The application of this technique seems to offer the best option for a selected group of neonates. It allows for the ideal aortic valve replacement for newborns as well as young children. The absence of the need for anticoagulation, the demonstrated long-term viability and, most importantly, the growth potential allow for the best possible combination of benefits. Homograft right ventricular outflow tract replacement should be straightforward when needed later.
References I. CastaIieda AR, Jonas RA, Mayer JE, Hanley FL. Cardiac surgery of the neonate and infant. 1st ed. Philadelphia: Saunders, lYY4:384-95. 2. Frommelt PC, Rocchini AI’, Rove EL. Natural history of apical left ventricular to aortic conduits in pediatric patients. Circulation 1991;84(Suppl 3):213-8. ;. Di Donate RM, Danielson GK, McGoon DC, et al. Left ventricle-aortic conduits in pediatric patients. J Thorac Cardiovasc Surg 1984;88:82-91. 4. McKowcn RI., Campbell DN, Woelfel F, Wiggins JW Jr, Clark DR. Extended am-tic root replacement with aortic allogrnft\. 1 Thorac Cardiovasc Surg 1987;93:366-74. Frommt~lt PC, Lupinetti FM, Bove EL. Aortoventriculoplasty in infants and children. Circulation lY92;86(Suppl2):176-80. Ross DN. Replacement of aortic and mitral valves with a pulmonarv autograft. Lancet 1967;2:956. Rohlc\ ,I, Laughan M, Lau JK, Bodnar E, Ross DN. Longterm a
Procedure
for Critical
Aortic
Stenosis
John H. Calhoon, MD, and Joe W. R. Bolton, MD Division of Cardiothoracic
Surger!,
Lniversitv
of Texas Health Science Center at San Antonio,
San Antonio,
Texas
Although the Ross procedure has been applied successfully to the pediatric age group, it may have its ideal application in the selected infant with critical aortic stenosis and complex left ventricular outflow tract obstruction with adequate ventricular function and size. Two neonates presented with critical aortic stenosis and
complex left ventricular outflow tract obstructiou, and a combined Ross/Konno procedure was performed successfully. These cases are presented along with a discussion of this topic.
P
discharged to home after several weeks. Improvement continued since discharge, and his most recent echocardiogram done at 23 months of age showed sinus rhythm and a normally functioning neo-aortic valve with no regurgitation, mild mitral valve regurgitation with associated mild-to-moderate pulmonary hypertension, and trace tricuspid regurgitation. The left ventricular contractility is normal with a shortening fraction of 0.40. The echocardiogram suggests true growth consistent with cardiac dimensions, with the autograft measuring 9 to 70 mm at implantation and now 12 to 13 mm in diameter (Figs 7, 2). His weight has increased from 4.0 kg at birth to 10 kg, and he remains in the 25th percentile for weight and height.
alliation of infants with critical aortic stenosis continues to be a challenge for those cardiologists and cardiac surgeons caring for such children. However, when this problem is compounded by associated complex left ventricular outflow tract obstruction, the results have been even less satisfying. If not amenable to valvotomy, the alternatives for a trzo-ventricle repair include cardiac transplantation, aortoventriculoplasty (ie, Konno procedure) with placement of a mechanical prosthesis or allograft, or insertion of a left ventricular-aortic conduit. Some infants have required conversion to a singlrventricle repair with a Norwood procedure when the left ventricular outflow tract obstruction was severe.
Case Reports
(Ann Tkorac Surg 1995;6O:S597-9)
has
Patient 2 Patient 1 presented to the University Hospital in San Antonio on day 1 of life with congestive heart failure requiring intubation and administration of prostaglandin E,. An echocardiogram revealed severe congenital aortic stenosis with a 4-mm aortic annulus and a tremendouslv dysplastic unicusp-appearing aortic valve. There M a\ severe mitral regurgitation and a decreased left ventricular ejection fraction. It was thought, however, that the left ventricular volume was adequate to support the systemic circulation. After discussions with the parents, we resuscitated the child and took him to the operating room, where a pulmonarv autograft aortic root replacement was performed along with enlargement of the left ventricular outflow tract by a Konno procedure. The right ventricular outflow tract \j’as reconstructed with a l-l-mm aortic tiomograft. Postoperatively, there was poor left \rcntricular compliante associated with moderate mitral and tricuspid regurgitation. This gradually improved and the child was
Patient 2 was transferred to The University Hospital in Antonio on day 6 of life with an echocardiogram that showed critical aortic annular stenosis with a severely dvsplastic aortic valve, moderate mitral regurgitation, and diminished left ventricular function. After multidisciplinarv discussions we thought that an infant Ross procedure might afford the child the best option for normal left ventricular outflow growth and long-term benefit. The child was therefore taken to the operating room where he underwent a Ross pulmonary autograft aortic valve replacement with a Konno left ventricular outflow tract enlargement and right ventricular outflow tract reconstruction with a 13-mm pulmonary homograft. The postoperative course was complicated only by seiTures, which were easily controlled with phenobarbital. lie was discharged to home receiving only furosemide and was doing well 5 months postoperatively. His weight had increased from 3.3 to 4.4 kg. An echocardiogram performed at that time showed a normal neo-aortic valve and left ventricular outflow tract. The coronary arteries and heart chambers were normal, and there was only mild tnitral regurgitation. San
0003-4975/95/$9.50 SSDI 0003-4975(95)00816-O
Ann Thorac Surg 1995;60:5597-9
Comment The problem of complt’x nt~onatal aortic \.al\c htcxnohi\ can be challenging. In the major-it\. ot cams of isolated aortic valve stenosis palliation nl~~~ be accomplished b\ balloon dilation of the stenotic aoitic valve. This usualI; offers good short-term and internlt~diate-terlii rtahult\ However, if the valvular +teno& i\ complicated by J severelv dysplastic \.alve (\+.hich ma\ also be incomptatent), annular stenosis, sub\~al\~ular \Gnosib, or hupra\,,ilvular outflow tract stenosis, the abilit\ to attain a sati\factory result with balloon dilation i\ unlikeI\ 111. In addition, the likelihood of a Gmple ~~pc~rati\,t~ solutic\n in these situations is poor. The evolution ot the SLII-~I~-,I~ optlcln\ tot- tht, treatment of coniplt~w neonatal .Iortic’ \,JI\ t’ stc)no\l\ has includt,d no therapv, left ~cntricular to aorta \ al\td conduits, rlorto~entriculoplaitv tie, Kc~iliic~ procedure) to d~~o~ii~ilc~date allograft or mc\chanic,ll vdI\ ~9rc~plact~mcnt, nconat.ll cardiac transyl,lnt,lticln, Clll~i <‘oII\ kll-5ioli to single-vtbntrlcle phvsiolog\r through a Yor\~t~~~d I~roct~dul<‘. L ntclrtu
nately, each of these options is far from ideal and has resulted in either limited success or significant morbidity. Although the option of no treatment is occasionally correct, we believe this should be reserved for those infants who have other associated congenital defects that will result in death in and of themselves. Likewise, the conversion to a single-ventricle physiology through the use of the Norwood procedure should be reserved for those neonates whose ventricular size is not capable of supporting the systemic circulation. On the other hand, cardiac transplantation is primarily limited by the availability of suitable donor hearts. The morbidity and expense of supporting these neonates until an organ can be located must be considered. There also remains the long-term complications of immunosuppression and rejection after transplantation. The use of left ventricular aortic conduits for the intermediate palliation of complex left ventricular outflow tract obstruction has been reported in the pediatric age group. Frommelt and co-workers (21 reported their experience of using this technique in 20 pediatric patients and concluded that this may be useful in the palliation of selected patients as a staging procedure. Unfortunately, both of the early deaths in this series occurred in infants less than 2 months of age. Excellent relief of left ventricular outflow tract obstruction was obtained using left ventricular to aortic conduits in a series reported by Di Donato and colleagues [3]. Again, however, there was a high incidence of late complications requiring reoperation (7 of 9 survivors), and all 3 patients less than 2 years old had fibroelastosis and died. T‘he next step in the evolution of treatment of complex congenital left ventricular outflow tract obstruction in\;olved root-enlarging procedures to accommodate allograft and mechanical valve prostheses. After a review of their experience with left ventricle to aorta conduits Di Donato and colleagues [3] report that they prefer aortoventriculoplasty and placement of a nontissue valve in the natural subaortic position. However, even with the availability of smaller mechanical valves, there is a very limited role for mechanical valve placement in the neoIlate.
IlrKowen and associates [41 also reported on the use of extended aortic root replacement with associated aortoventriculoplasty in 3 patients. This group chose to use cryopreserved allograft valves and had no mortality, limited morbidity, and good functional results. The youngest patient in this report was 4% years old. A \imilar good experience with the use of this technique LVZ reported by Frommelt and associates [5]. In lYh7, Ross [6] first described the use of a pulmonary \-alve autograft to replace the aortic valve, and even as earlv as 7985, while options for the treatment of neonatal aortic valve stenosis were being explored, Robles and associates [7] working with Ross reported on 202 autologous pulmonary valve transplants for aortic valve replacement in adults and children. They concluded that “the long term performance of a pulmonary autograft inserted for aortic valve disease is superior to any other
Ann Thorai 5urg lY95;6O:S597-Y
valve substitute and that the operation offers an almost ideal means of aortic valve replacement in appropriate patients.” The youngest patient in that series was 9 years old, but it was noted that there had been “no incident of embolism and no evidence of calcification” in 14 vears of follow-up. More recently, in 1993, Kumar and colleagues [H] reported on 45 patients with a mean age of 77 years who underwent a Ross procedure for rheumatic heart disease. Although there was only a s-year follow-up, there were no early or late deaths and only 1 patient required reoperation at 2 years for a regurgitant pulmonary autograft. They concluded that pulmonary autograft transplantation to the aortic root may offer a near-permanent solution for the young rheumatic population with valve disease. The technique of ventriculoplasty to accommodate allograft placement in the younger age group has been well described by Clark 191. It is the use of this technique that allows insertion of the larger pulmonary autograft root into the stenotic left ventricular outflow tract. In addition to the forementioned techniques, research by others has contributed to our understanding of differences in pulmonary and aortic allograft behavior. Furthermore, studies have shown that incorporation of a live autograft allows for growth, and technical advancements have revealed that the ideal placement of the neo-aortic roots is intraannular. Each of these advancements has been made possible through the refinements of cardiopulmonary bypass techniques allowing for safe conduct of complex congenital cardiac repairs on neonates. Thus, building on this vast legacy, the next logical step in the evolution of the treatment of this condition was embarked upon. There are numerous advantages to a combined ROSS/ Konno procedure in the select group of neonates with complicated aortic valve stenosis and left ventricular outflow tract obstruction. The tissue valve avoids the problems with sizing, thrombosis, and anticoagulation as compared with a mechanical prosthesis. By using the pulmonary root there is identical design and placcment with respect to the native aortic root. Furthermore, the use of the pulmonary autograft has shown no immunologic rejection and no tissue decay, requires no supporting stent, and has shown true growth potential a\ compared with other tissue valves or cryopreserved allografts. There is also the theoretic advantage of improved longevitv and decreased calcification when the cryopreserved allograft is placed in the lower pressure pilmonary outflow tract [l, lo]. The procedure is not without its disadvantages, however. At the onset, the ability of the systemic ventricle to support the circulation must be ensured and the native pulmonary valve must be normal. The ventriculoplast! carries the risk of heart block, and there are immediate, intermediate and long-term problems attendant to mobilization and reimplantation of the coronary artcric5.
( \5 I Ar\t
DA FtSTSCHRIFT ROSSIKOXNO
(-AL tiOON PROCEDURE
AND BOLTON IN IA’FANCY
s599
The autotransplant itself converts a single-valve replacement into a double-valve replacement. Finally, the relative difficulty of the operation in an already acutely ill neonate represents a challenge in and of itself. Because of the very small aortic annulus and severely dysplastic aortic valve presented in these 2 cases it was thought that the possibility of successful valvotomy using a balloon or open technique was remote. The options of no intervention, cardiac transplantation, and Norwood procedure were entertained but rejected. These critically ill children were salvageable due to adequate left ventricular volume and function to support a two-ventricle repair. Thus, pulmonary valve autotransplantation with aortoventriculoplasty and right ventricular outflow tract reconstruction using cryopreserved allograft was performed. Subsequently, there has been presumed growth of the neo-aortic valve and root with improved ventricular function over 2 years without need for further intervention. The application of this technique seems to offer the best option for a selected group of neonates. It allows for the ideal aortic valve replacement for newborns as well as young children. The absence of the need for anticoagulation, the demonstrated long-term viability and, most importantly, the growth potential allow for the best possible combination of benefits. Homograft right ventricular outflow tract replacement should be straightforward when needed later.
References I. CastaIieda AR, Jonas RA, Mayer JE, Hanley FL. Cardiac surgery of the neonate and infant. 1st ed. Philadelphia: Saunders, lYY4:384-95. 2. Frommelt PC, Rocchini AI’, Rove EL. Natural history of apical left ventricular to aortic conduits in pediatric patients. Circulation 1991;84(Suppl 3):213-8. ;. Di Donate RM, Danielson GK, McGoon DC, et al. Left ventricle-aortic conduits in pediatric patients. J Thorac Cardiovasc Surg 1984;88:82-91. 4. McKowcn RI., Campbell DN, Woelfel F, Wiggins JW Jr, Clark DR. Extended am-tic root replacement with aortic allogrnft\. 1 Thorac Cardiovasc Surg 1987;93:366-74. Frommt~lt PC, Lupinetti FM, Bove EL. Aortoventriculoplasty in infants and children. Circulation lY92;86(Suppl2):176-80. Ross DN. Replacement of aortic and mitral valves with a pulmonarv autograft. Lancet 1967;2:956. Rohlc\ ,I, Laughan M, Lau JK, Bodnar E, Ross DN. Longterm a