Cardiology in the Young (2013), 23, 933–937
r Cambridge University Press, 2013
doi:10.1017/S1047951113001959
Original Article Surgical management of tetralogy of Fallot: where are we now and what is yet to come* Marshall L. Jacobs, Luca A. Vricella Department of Surgery, Division of Cardiac Surgery, John Hopkins School of Medicine, Baltimore, Maryland, United States of America Keywords: Congenital heart disease; databases; tetralogy of Fallot; surgery
HE EVOLUTION OF SURGICAL MANAGEMENT OF
>
tetralogy of Fallot dates back to November 29, 1944, when Alfred Blalock performed the first operation on a cyanotic child aged 1 year with tetralogy of Fallot at Johns Hopkins Hospital in Baltimore. A decade later, on August 31, 1954, C. Walton Lillehei performed the first successful repair of tetralogy of Fallot using controlled crosscirculation at the University of Minnesota. The first successful repair of tetralogy of Fallot using a mechanical pump oxygenator – heart-lung bypass machine – was achieved by John Kirklin at the Mayo Clinic in 1955.1 It is no surprise that approaches to surgical management of tetralogy have evolved considerably. Interestingly, many of the controversial issues concerning timing and technique of repair that were the subjects of ongoing debates across many decades remain incompletely resolved today. These include the following issues:
>
T
>
>
The role of palliative shunt procedures before definitive reparative surgery, particularly in symptomatic neonates and very young infants. The role of right ventricular outflow procedures as alternatives to palliative systemic-to-pulmonary artery shunt.
*Presented at ‘‘The Birth of Heart Surgery: Lessons Learned from Tetralogy – Past, Present and Future’’ Dinner Symposium sponsored by Johns Hopkins Medicine and All Children’s Hospital, Thursday, February 21, 2013, at The Sixth World Congress of Paediatric Cardiology and Cardiac Surgery, Cape Town International Convention Centre, Cape Town, South Africa, February 17–22, 2013. A video of this presentation can be viewed at the following hyperlink: [http:// www.allkids.org/wcpccs]. Correspondence to: Dr M. L. Jacobs MD, Division of Cardiac Surgery, Johns Hopkins School of Medicine, 1800 Orleans Street, Sheikh Zayed Tower/Suite 7107, Baltimore, Maryland 21287, United States of America. Tel: 1410-9552800; Fax: 1410-502-2399; E-mail: [email protected]
>
>
>
Optimal timing of primary repair. The appropriate use and short- and long-term implications of transannular patch reconstruction of the right ventricular outflow tract. The appropriate application and optimal techniques of ‘‘valve-sparing’’ reparative operations. The operative approach to closure of the ventricular septal defect and relief of right ventricular outflow tract obstruction: transventricular versus transatrial versus combined. The timing, indications, approach, and choice of valve substitute for patients with significant pulmonary insufficiency and right ventricular enlargement late after repair of tetralogy of Fallot.
Where we are now With respect to the above-mentioned controversies, the best way to get a snapshot of current practices is to evaluate contemporary data as entered in multicentre and multi-national databases. The Society of Thoracic Surgeons Congenital Heart Surgery Database is the largest registry of paediatric and congenital heart surgery cases in North America, with over 100 participating centres. In 2010, a review was done of all data in the Society of Thoracic Surgeons Congenital Heart Surgery Database pertaining to surgical operations on patients 0–18 years of age with tetralogy of Fallot with pulmonary stenosis over the 5-year period 2002–2007.2 Patients with tetralogy of Fallot with pulmonary atresia, tetralogy of Fallot with absent pulmonary valve, and tetralogy of Fallot with common atrioventricular canal defect were excluded. The data set encompassed ,3000 operations. Just slightly more than 10% of all operations were some type of palliation, of which the
581 571 1331 53 2536 28 48 60 18 154 44 37 58 6 145 172 169 266 7 614 237 222 508 9 976 9 13 127 6 155 TOF repair, no ventriculotomy TOF repair, ventriculotomy, non-transannular patch TOF repair, ventriculotomy, transannular patch TOF repair, RV–PA conduit All operations
91 82 312 7 492
.2–18 years .1–2 years .6 months to 1 year .3–6 months .30 days to 3 months 0–30 days TOF repair without previous surgery: type of repair
overwhelming majority were systemic-to-pulmonary artery shunts. Among reparative operations, there were 2534 instances of repair of tetralogy of Fallot without a previous cardiac operation, that is, primary repair, and 217 instances of repair of tetralogy of Fallot with a previous cardiac operation. Associations between age and procedure types were assessed. For the neonatal age group (age 0–30 days), initial procedures were about equally divided between tetralogy of Fallot repair and palliation. Across all age groups, the largest number of primary repairs was between 3 and 6 months of age, followed by the 6-month to 1-year category (Fig 1). The largest number of repairs after palliation was in the 6-month to 1-year age category, with 81% of repairs after a previous cardiac operation being performed during the first year of life. Across all age groups, by far the most prevalent surgical approach utilised at the time of primary reparative operations was a ventriculotomy approach with transannular patch reconstruction of the right ventricular outflow tract (Table 1). At the time of primary repair, 52% of patients (1329 of 2534) had ventriculotomy and transannular patch. Only 581 patients (23%) had primary repair with no ventriculotomy (Fig 2). Repair after prior palliation was performed in 217 cases. Although proponents of an approach based on palliative shunting of symptomatic neonates followed by secondary repair have argued that a potential advantage of this two-staged approach may be interval growth of the pulmonary annulus and reduction of the need for transannular patching, it was nonetheless the case that among patients having reparative surgery after prior palliation, ventriculotomy with transannular patch reconstruction of the right ventricular outflow tract was the most prevalent approach (143 of 217; 66%). Although the focus of the analysis of Society of Thoracic Surgeons Congenital Heart Surgery Database data was on patterns of practice, and although no risk-adjusted analysis of mortality
Table 1. Tetralogy of Fallot repair without previous surgery: Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
Figure 1. Primary repair of tetralogy of Fallot in the Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
RV–PA 5 right ventricle-to-pulmonary artery; TOF 5 tetralogy of Fallot The relationship between specific type of repair and age at repair for all instances of TOF repair without previous cardiac surgery. Repair with ventriculotomy and transannular patch is the most prevalent type overall (52% of total), and is most prevalent in every age category. The largest number of instances of primary repair of any type was in the age category of .3–6 months, followed by 6 months to 1 year. Adapted from Al Habib et al2
December 2013
Cardiology in the Young All ages
934
Vol. 23, No. 6
Jacobs et al: Surgical management of tetralogy of Fallot
Figure 2. Primary repair of tetralogy of Fallot in the Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
was undertaken, it was reassuring to observe that unadjusted discharge mortality associated with primary repair was just 1.3% (confidence interval: 0.9–1.8%), and was 0.9% (confidence interval: 0.1–3.3%) for repair after previous palliation. Overall discharge mortality associated with initial palliative procedures was 7.5% (confidence interval: 4.7–11.1%). For neonates, discharge mortality was similar among those who underwent palliation and those who had primary repair. A similar analysis of slightly more recent data was undertaken by members of the European Congenital Heart Surgeons Association, based upon data in the European Association for Cardio-thoracic Surgery Congenital Heart Surgery Database, which is the largest database in Europe dealing with surgical management of congenital cardiac malformations. The data set consisted of all types of reparative operations (n 5 6654) on patients with a primary diagnosis of tetralogy of Fallot between 1999 and 2011.3 Similarities between North American data and the European Association for Cardio-thoracic Surgery data were striking. Repair via ventriculotomy with transannular patch was the most prevalent technique (n 5 3827; 57.5%). Repair via ventriculotomy with non-transannular patch was performed in 1309 patients (19.7%). Repair without ventriculotomy was performed in 1214 patients (18.2%). The investigators explored timerelated trends with respect to the various sub-types of repair. Over the past decade, the relative prevalence of types of operations was rather static, with repair with no ventriculotomy hovering around 20%.
What all these data tell us Despite the fact that there is now a general appreciation of the importance of chronic pulmonary
935
insufficiency after repair of tetralogy of Fallot and its potential impact on right ventricular size and function over a period of years,4-7 these data from both the North American and the European registries tell us that repair by means of right ventriculotomy with transannular patch is the most prevalent surgical technique. This technique is followed in frequency by repair with ventriculotomy and non-transannular patching. Repair without ventriculotomy accounts for less than onefourth of primary repairs. It is important to note that of patients who undergo repair of tetralogy after previous palliation, the majority undergo transannular incision and patching at the time of eventual repair. Understanding that awareness of important late-phase events – re-operation, ventricular dysfunction, arrhythmias, and the risk of sudden cardiac death – undoubtedly influences patterns of referral and surgical practice, it is important to acknowledge that this awareness has not resulted in across-the-board diminution in the use of ventriculotomy incision or transannular patching. This is not because congenital heart surgeons have failed to explore the efficacy of other strategies or have failed to advocate for surgical techniques that maximise preservation of pulmonary valve competence whenever possible and minimise transannular and transmural right ventricular incisions whenever possible. Some have hypothesised that a strategy in which one initially treats severely cyanotic and symptomatic infants by construction of systemic-to-pulmonary artery shunts with postponement of definitive repair until the age of 1 year may be accompanied by salutary increase in the Z-value of the pulmonary valve annulus during the interval period, theoretically making possible a reduction in the need for transannular patching.8 Although the frequency of reoperations during intermediate-term follow-up has been relatively low in some series of patients treated in this way, actual data regarding the question of disproportionate growth of the pulmonary annulus are limited, and the question has not been evaluated from a multi-institutional perspective. The respective advantages of the so-called transatrial versus transventricular repair techniques remain a matter of controversy. Proponents of transatrial – or transatrial/transpulmonary artery – approach to repair of tetralogy of Fallot postulate that it would result in reduced incidence of right ventricular dilatation requiring later implantation of a pulmonary valve. The safety of this approach has certainly been demonstrated on the basis of excellent results with very low operative mortality achieved at several centres.9,10 The results in Melbourne, Australia, over more than three decades have been outstanding, including one of the lowest
936
Cardiology in the Young
rates of mortality in any large series of operations for tetralogy. D’Udekem and associates from Melbourne presented a comprehensive analysis of this cohort at the 2013 meeting of the American Association for Thoracic Surgery.11 In this large cohort, transannular patching was performed in 75% of cases. What was most unique about this analysis was the observation that despite the fact that all surgeons used the transatrial repair technique, the rate of subsequent re-operations for either pulmonary insufficiency or right ventricular outflow tract obstruction varied considerably – and essentially inversely – between individual surgeons. The rate of re-intervention at 10 years varied among individual surgeons, between 8.8% and 26.7%. At 25 years, the overall freedom from re-operation was 75%. It should come as no surprise that, regardless of what surgical approach is used for closure of the ventricular septal defect and division of septoparietal trabeculations, certain fundamental aspects of the outcome from surgery for tetralogy are inextricably related to the individual patient’s underlying morphology: (1) certain patients have a sufficiently severe degree of hypoplasia of the pulmonary valve annulus that transannular incision simply cannot be avoided, except at the expense of nearly systemic-level pressure in the right ventricle; and (2) in many cases, the goals of achieving adequate relief of right ventricular outflow tract obstruction while maintaining competence of the pulmonary valve are mutually exclusive. As described by D’Udekem in relation to the Melbourne experience, even surgeons who consistently rely on transatrial approach to the ventricular septal defect, believing that this results in a smaller incision of the outflow tract and better preservation of right ventricular function, must decide how widely to open the right ventricular outflow tract, and how much of a residual pressure gradient across the outflow tract is acceptable. These general questions are more vexing than the question of how to approach the ventricular septal defect. They are probably also more important in the long run – and currently they remain unresolved. Another technical issue relates to the question of what can be accomplished at the level of the pulmonary valve and annulus as an alternative to transannular incision. This falls under the general heading of ‘‘valve sparing’’ approaches to surgery.12 Numerous techniques have been utilised, but none, of course, are applicable to all patients. Surgical techniques, initially limited to extensive valvotomy and patch augmentation of the pulmonary trunk and sinuses, are now extended to include patch augmentation of the pulmonary valve, and also include interventional strategies such as intra-operative balloon dilation.13,14
December 2013
For neonates with prematurity, low birth weight, severe hypoplasia of the pulmonary annulus and branch pulmonary arteries, or other factors that may be associated with increased risk of primary repair, the contemporary spectrum of palliative approaches includes innovative techniques such as transcatheter balloon dilation of the pulmonary valve or stent deployment in the right ventricular outflow tract, as alternatives to, or in addition to, surgical construction of systemic-to-pulmonary artery shunts.15 Finally, it is essential to acknowledge that the operation wherein patients with tetralogy of Fallot undergo closure of the ventricular septal defect and relief of the right ventricular outflow tract obstruction must be viewed as ‘‘reparative surgery’’ and not as ‘‘total correction’’, the latter term having been used extensively during the 1980s. A rational approach to life-long care of patients who have undergone repair of tetralogy of Fallot in infancy is based upon regular evaluations and the recognition that appropriately timed subsequent procedures, such as surgical or transcatheter pulmonary valve replacement, are critically important and sometimes unavoidable in order to preserve right ventricular function and maximise the functional capacity of the patient.
References 1. Jacobs ML, Jacobs JP. The history of surgery for patients with tetralogy of Fallot. Cardiol Young 2008; 18 (Suppl 3): 8–11. 2. Al Habib HF, Jacobs JP, Mavroudis C, et al. Contemporary patterns of management of tetralogy of Fallot: data from the Society of Thoracic Surgeons Database. Ann Thorac Surg 2010; 90: 813–819. 3. Sarris GE, Comas JV, Tobota Z, Maruszewski B. Results of reparative surgery for tetralogy of Fallot: data from the European Association for Cardio-Thoracic Surgery Congenital Database. Eur J Cardiothorac Surg 2012; 42: 766–774; discussion 774. 4. Zahka KG, Horneffer PJ, Rowe SA, et al. Long-term valvular function after total repair of tetralogy of Fallot. Relation to ventricular arrhythmias. Circulation 1988; 78 (Pt 2): III14–III19. 5. Bouzas B, Kilner PJ, Gatzoulis MA. Pulmonary regurgitation: not a benign lesion. Eur Heart J 2005; 26: 433–439. 6. Therrien J, Siu SC, McLaughlin PR, et al. Pulmonary valve replacement in adults late after repair of tetralogy of Fallot: are we operating too late? J Am Coll Cardiol 2000; 35: 1670–1675. 7. Davlouros PA, Karatza AA, Gatzoulis MA, Shore DF. Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot. Int J Cardiol 2004; 97 (Suppl 1): 91–101. 8. Fraser CD Jr, McKenzie ED, Cooley DA. Tetralogy of Fallot: surgical management individualized to the patient. Ann Thorac Surg 2001; 71: 1556–1561. 9. Padalino MA, Vida VL, Stellin G. Transatrial-transpulmonary repair of tetralogy of Fallot. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2009: 48–53; Review. 10. Karl TR, Sano S, Pornviliwan S, Mee RB. Tetralogy of Fallot: favorable outcome of nonneonatal transatrial, transpulmonary repair. Ann Thorac Surg 1992; 54: 903–907.
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Jacobs et al: Surgical management of tetralogy of Fallot
11. D’Udekem Y, Galati JC, Konstantinov IE, Cheung M, Brizard CP. Inter-surgeon variability in long-term outcomes after transatrial repair of tetralogy of Fallot: 25 years experience with 675 patients, 93rd Annual Meeting of the American Association for Thoracic Surgery. Abstract 37, pp. 198–199. 12. Stewart RD, Backer CL, Young L, Mavroudis C. Tetralogy of Fallot: results of a pulmonary valve-sparing strategy. Ann Thorac Surg 2005; 80: 1431–1438.
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13. Robinson JD, Rathod RH, Brown DW, et al. The evolving role of intraoperative balloon pulmonary valvuloplasty in valve-sparing repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 2011; 142: 1367–1373. 14. Bacha E. Valve-sparing options in tetralogy of Fallot surgery. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2012; 15: 24–26. 15. Barron DJ. Tetralogy of Fallot: controversies in early management. World J Pediatr Congenit Heart Surg 2013; 4: 186–191.
r Cambridge University Press, 2013
doi:10.1017/S1047951113001959
Original Article Surgical management of tetralogy of Fallot: where are we now and what is yet to come* Marshall L. Jacobs, Luca A. Vricella Department of Surgery, Division of Cardiac Surgery, John Hopkins School of Medicine, Baltimore, Maryland, United States of America Keywords: Congenital heart disease; databases; tetralogy of Fallot; surgery
HE EVOLUTION OF SURGICAL MANAGEMENT OF
>
tetralogy of Fallot dates back to November 29, 1944, when Alfred Blalock performed the first operation on a cyanotic child aged 1 year with tetralogy of Fallot at Johns Hopkins Hospital in Baltimore. A decade later, on August 31, 1954, C. Walton Lillehei performed the first successful repair of tetralogy of Fallot using controlled crosscirculation at the University of Minnesota. The first successful repair of tetralogy of Fallot using a mechanical pump oxygenator – heart-lung bypass machine – was achieved by John Kirklin at the Mayo Clinic in 1955.1 It is no surprise that approaches to surgical management of tetralogy have evolved considerably. Interestingly, many of the controversial issues concerning timing and technique of repair that were the subjects of ongoing debates across many decades remain incompletely resolved today. These include the following issues:
>
T
>
>
The role of palliative shunt procedures before definitive reparative surgery, particularly in symptomatic neonates and very young infants. The role of right ventricular outflow procedures as alternatives to palliative systemic-to-pulmonary artery shunt.
*Presented at ‘‘The Birth of Heart Surgery: Lessons Learned from Tetralogy – Past, Present and Future’’ Dinner Symposium sponsored by Johns Hopkins Medicine and All Children’s Hospital, Thursday, February 21, 2013, at The Sixth World Congress of Paediatric Cardiology and Cardiac Surgery, Cape Town International Convention Centre, Cape Town, South Africa, February 17–22, 2013. A video of this presentation can be viewed at the following hyperlink: [http:// www.allkids.org/wcpccs]. Correspondence to: Dr M. L. Jacobs MD, Division of Cardiac Surgery, Johns Hopkins School of Medicine, 1800 Orleans Street, Sheikh Zayed Tower/Suite 7107, Baltimore, Maryland 21287, United States of America. Tel: 1410-9552800; Fax: 1410-502-2399; E-mail: [email protected]
>
>
>
Optimal timing of primary repair. The appropriate use and short- and long-term implications of transannular patch reconstruction of the right ventricular outflow tract. The appropriate application and optimal techniques of ‘‘valve-sparing’’ reparative operations. The operative approach to closure of the ventricular septal defect and relief of right ventricular outflow tract obstruction: transventricular versus transatrial versus combined. The timing, indications, approach, and choice of valve substitute for patients with significant pulmonary insufficiency and right ventricular enlargement late after repair of tetralogy of Fallot.
Where we are now With respect to the above-mentioned controversies, the best way to get a snapshot of current practices is to evaluate contemporary data as entered in multicentre and multi-national databases. The Society of Thoracic Surgeons Congenital Heart Surgery Database is the largest registry of paediatric and congenital heart surgery cases in North America, with over 100 participating centres. In 2010, a review was done of all data in the Society of Thoracic Surgeons Congenital Heart Surgery Database pertaining to surgical operations on patients 0–18 years of age with tetralogy of Fallot with pulmonary stenosis over the 5-year period 2002–2007.2 Patients with tetralogy of Fallot with pulmonary atresia, tetralogy of Fallot with absent pulmonary valve, and tetralogy of Fallot with common atrioventricular canal defect were excluded. The data set encompassed ,3000 operations. Just slightly more than 10% of all operations were some type of palliation, of which the
581 571 1331 53 2536 28 48 60 18 154 44 37 58 6 145 172 169 266 7 614 237 222 508 9 976 9 13 127 6 155 TOF repair, no ventriculotomy TOF repair, ventriculotomy, non-transannular patch TOF repair, ventriculotomy, transannular patch TOF repair, RV–PA conduit All operations
91 82 312 7 492
.2–18 years .1–2 years .6 months to 1 year .3–6 months .30 days to 3 months 0–30 days TOF repair without previous surgery: type of repair
overwhelming majority were systemic-to-pulmonary artery shunts. Among reparative operations, there were 2534 instances of repair of tetralogy of Fallot without a previous cardiac operation, that is, primary repair, and 217 instances of repair of tetralogy of Fallot with a previous cardiac operation. Associations between age and procedure types were assessed. For the neonatal age group (age 0–30 days), initial procedures were about equally divided between tetralogy of Fallot repair and palliation. Across all age groups, the largest number of primary repairs was between 3 and 6 months of age, followed by the 6-month to 1-year category (Fig 1). The largest number of repairs after palliation was in the 6-month to 1-year age category, with 81% of repairs after a previous cardiac operation being performed during the first year of life. Across all age groups, by far the most prevalent surgical approach utilised at the time of primary reparative operations was a ventriculotomy approach with transannular patch reconstruction of the right ventricular outflow tract (Table 1). At the time of primary repair, 52% of patients (1329 of 2534) had ventriculotomy and transannular patch. Only 581 patients (23%) had primary repair with no ventriculotomy (Fig 2). Repair after prior palliation was performed in 217 cases. Although proponents of an approach based on palliative shunting of symptomatic neonates followed by secondary repair have argued that a potential advantage of this two-staged approach may be interval growth of the pulmonary annulus and reduction of the need for transannular patching, it was nonetheless the case that among patients having reparative surgery after prior palliation, ventriculotomy with transannular patch reconstruction of the right ventricular outflow tract was the most prevalent approach (143 of 217; 66%). Although the focus of the analysis of Society of Thoracic Surgeons Congenital Heart Surgery Database data was on patterns of practice, and although no risk-adjusted analysis of mortality
Table 1. Tetralogy of Fallot repair without previous surgery: Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
Figure 1. Primary repair of tetralogy of Fallot in the Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
RV–PA 5 right ventricle-to-pulmonary artery; TOF 5 tetralogy of Fallot The relationship between specific type of repair and age at repair for all instances of TOF repair without previous cardiac surgery. Repair with ventriculotomy and transannular patch is the most prevalent type overall (52% of total), and is most prevalent in every age category. The largest number of instances of primary repair of any type was in the age category of .3–6 months, followed by 6 months to 1 year. Adapted from Al Habib et al2
December 2013
Cardiology in the Young All ages
934
Vol. 23, No. 6
Jacobs et al: Surgical management of tetralogy of Fallot
Figure 2. Primary repair of tetralogy of Fallot in the Society of Thoracic Surgeons Congenital Heart Surgery Database 2002–2007.
was undertaken, it was reassuring to observe that unadjusted discharge mortality associated with primary repair was just 1.3% (confidence interval: 0.9–1.8%), and was 0.9% (confidence interval: 0.1–3.3%) for repair after previous palliation. Overall discharge mortality associated with initial palliative procedures was 7.5% (confidence interval: 4.7–11.1%). For neonates, discharge mortality was similar among those who underwent palliation and those who had primary repair. A similar analysis of slightly more recent data was undertaken by members of the European Congenital Heart Surgeons Association, based upon data in the European Association for Cardio-thoracic Surgery Congenital Heart Surgery Database, which is the largest database in Europe dealing with surgical management of congenital cardiac malformations. The data set consisted of all types of reparative operations (n 5 6654) on patients with a primary diagnosis of tetralogy of Fallot between 1999 and 2011.3 Similarities between North American data and the European Association for Cardio-thoracic Surgery data were striking. Repair via ventriculotomy with transannular patch was the most prevalent technique (n 5 3827; 57.5%). Repair via ventriculotomy with non-transannular patch was performed in 1309 patients (19.7%). Repair without ventriculotomy was performed in 1214 patients (18.2%). The investigators explored timerelated trends with respect to the various sub-types of repair. Over the past decade, the relative prevalence of types of operations was rather static, with repair with no ventriculotomy hovering around 20%.
What all these data tell us Despite the fact that there is now a general appreciation of the importance of chronic pulmonary
935
insufficiency after repair of tetralogy of Fallot and its potential impact on right ventricular size and function over a period of years,4-7 these data from both the North American and the European registries tell us that repair by means of right ventriculotomy with transannular patch is the most prevalent surgical technique. This technique is followed in frequency by repair with ventriculotomy and non-transannular patching. Repair without ventriculotomy accounts for less than onefourth of primary repairs. It is important to note that of patients who undergo repair of tetralogy after previous palliation, the majority undergo transannular incision and patching at the time of eventual repair. Understanding that awareness of important late-phase events – re-operation, ventricular dysfunction, arrhythmias, and the risk of sudden cardiac death – undoubtedly influences patterns of referral and surgical practice, it is important to acknowledge that this awareness has not resulted in across-the-board diminution in the use of ventriculotomy incision or transannular patching. This is not because congenital heart surgeons have failed to explore the efficacy of other strategies or have failed to advocate for surgical techniques that maximise preservation of pulmonary valve competence whenever possible and minimise transannular and transmural right ventricular incisions whenever possible. Some have hypothesised that a strategy in which one initially treats severely cyanotic and symptomatic infants by construction of systemic-to-pulmonary artery shunts with postponement of definitive repair until the age of 1 year may be accompanied by salutary increase in the Z-value of the pulmonary valve annulus during the interval period, theoretically making possible a reduction in the need for transannular patching.8 Although the frequency of reoperations during intermediate-term follow-up has been relatively low in some series of patients treated in this way, actual data regarding the question of disproportionate growth of the pulmonary annulus are limited, and the question has not been evaluated from a multi-institutional perspective. The respective advantages of the so-called transatrial versus transventricular repair techniques remain a matter of controversy. Proponents of transatrial – or transatrial/transpulmonary artery – approach to repair of tetralogy of Fallot postulate that it would result in reduced incidence of right ventricular dilatation requiring later implantation of a pulmonary valve. The safety of this approach has certainly been demonstrated on the basis of excellent results with very low operative mortality achieved at several centres.9,10 The results in Melbourne, Australia, over more than three decades have been outstanding, including one of the lowest
936
Cardiology in the Young
rates of mortality in any large series of operations for tetralogy. D’Udekem and associates from Melbourne presented a comprehensive analysis of this cohort at the 2013 meeting of the American Association for Thoracic Surgery.11 In this large cohort, transannular patching was performed in 75% of cases. What was most unique about this analysis was the observation that despite the fact that all surgeons used the transatrial repair technique, the rate of subsequent re-operations for either pulmonary insufficiency or right ventricular outflow tract obstruction varied considerably – and essentially inversely – between individual surgeons. The rate of re-intervention at 10 years varied among individual surgeons, between 8.8% and 26.7%. At 25 years, the overall freedom from re-operation was 75%. It should come as no surprise that, regardless of what surgical approach is used for closure of the ventricular septal defect and division of septoparietal trabeculations, certain fundamental aspects of the outcome from surgery for tetralogy are inextricably related to the individual patient’s underlying morphology: (1) certain patients have a sufficiently severe degree of hypoplasia of the pulmonary valve annulus that transannular incision simply cannot be avoided, except at the expense of nearly systemic-level pressure in the right ventricle; and (2) in many cases, the goals of achieving adequate relief of right ventricular outflow tract obstruction while maintaining competence of the pulmonary valve are mutually exclusive. As described by D’Udekem in relation to the Melbourne experience, even surgeons who consistently rely on transatrial approach to the ventricular septal defect, believing that this results in a smaller incision of the outflow tract and better preservation of right ventricular function, must decide how widely to open the right ventricular outflow tract, and how much of a residual pressure gradient across the outflow tract is acceptable. These general questions are more vexing than the question of how to approach the ventricular septal defect. They are probably also more important in the long run – and currently they remain unresolved. Another technical issue relates to the question of what can be accomplished at the level of the pulmonary valve and annulus as an alternative to transannular incision. This falls under the general heading of ‘‘valve sparing’’ approaches to surgery.12 Numerous techniques have been utilised, but none, of course, are applicable to all patients. Surgical techniques, initially limited to extensive valvotomy and patch augmentation of the pulmonary trunk and sinuses, are now extended to include patch augmentation of the pulmonary valve, and also include interventional strategies such as intra-operative balloon dilation.13,14
December 2013
For neonates with prematurity, low birth weight, severe hypoplasia of the pulmonary annulus and branch pulmonary arteries, or other factors that may be associated with increased risk of primary repair, the contemporary spectrum of palliative approaches includes innovative techniques such as transcatheter balloon dilation of the pulmonary valve or stent deployment in the right ventricular outflow tract, as alternatives to, or in addition to, surgical construction of systemic-to-pulmonary artery shunts.15 Finally, it is essential to acknowledge that the operation wherein patients with tetralogy of Fallot undergo closure of the ventricular septal defect and relief of the right ventricular outflow tract obstruction must be viewed as ‘‘reparative surgery’’ and not as ‘‘total correction’’, the latter term having been used extensively during the 1980s. A rational approach to life-long care of patients who have undergone repair of tetralogy of Fallot in infancy is based upon regular evaluations and the recognition that appropriately timed subsequent procedures, such as surgical or transcatheter pulmonary valve replacement, are critically important and sometimes unavoidable in order to preserve right ventricular function and maximise the functional capacity of the patient.
References 1. Jacobs ML, Jacobs JP. The history of surgery for patients with tetralogy of Fallot. Cardiol Young 2008; 18 (Suppl 3): 8–11. 2. Al Habib HF, Jacobs JP, Mavroudis C, et al. Contemporary patterns of management of tetralogy of Fallot: data from the Society of Thoracic Surgeons Database. Ann Thorac Surg 2010; 90: 813–819. 3. Sarris GE, Comas JV, Tobota Z, Maruszewski B. Results of reparative surgery for tetralogy of Fallot: data from the European Association for Cardio-Thoracic Surgery Congenital Database. Eur J Cardiothorac Surg 2012; 42: 766–774; discussion 774. 4. Zahka KG, Horneffer PJ, Rowe SA, et al. Long-term valvular function after total repair of tetralogy of Fallot. Relation to ventricular arrhythmias. Circulation 1988; 78 (Pt 2): III14–III19. 5. Bouzas B, Kilner PJ, Gatzoulis MA. Pulmonary regurgitation: not a benign lesion. Eur Heart J 2005; 26: 433–439. 6. Therrien J, Siu SC, McLaughlin PR, et al. Pulmonary valve replacement in adults late after repair of tetralogy of Fallot: are we operating too late? J Am Coll Cardiol 2000; 35: 1670–1675. 7. Davlouros PA, Karatza AA, Gatzoulis MA, Shore DF. Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot. Int J Cardiol 2004; 97 (Suppl 1): 91–101. 8. Fraser CD Jr, McKenzie ED, Cooley DA. Tetralogy of Fallot: surgical management individualized to the patient. Ann Thorac Surg 2001; 71: 1556–1561. 9. Padalino MA, Vida VL, Stellin G. Transatrial-transpulmonary repair of tetralogy of Fallot. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2009: 48–53; Review. 10. Karl TR, Sano S, Pornviliwan S, Mee RB. Tetralogy of Fallot: favorable outcome of nonneonatal transatrial, transpulmonary repair. Ann Thorac Surg 1992; 54: 903–907.
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Jacobs et al: Surgical management of tetralogy of Fallot
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