Routine primary repair of tetralogy of Fallot in neonates and infants less than three months of Age

Routine Primary Repair of Tetralogy of Fallot in Neonates and Infants Less Than Three Months of Age V. Mohan Reddy, MD, John R. Liddicoat, MD, Doff B. McElhinney, Michael M. Brook, MD, Paul Stanger, MD, and Frank L. Hanley, MD Divisions of Cardiothoracic

Surptarv and Pediatric Cardiologv.

Unit rr\it\

of California

San Francisco, San Francisco, California

Backgromd. Although primary repair of tetralogy of Fallot is increasingly undertaken in infancy, complete repair is generally performed in only s&cted symptomatic neonates. Methods. From July 1992 through March 1995, 30 consecutive neonates and young infants with tetralogy of Fallot underwent routine primary repair. Group I (n = 10) consisted of patients with tetralogy of Fallot and pulmonary atresia (n = 5) or severe pulmonary stenosis (n = 5) who were duct dependent and were repaired in the neonatal period. Group 11 (n = 11) consisted of patients who were asymptomatic with arterial oxygen saturation between 75% and 9O’C (adequate pulmonary blood flow). Group III (n = 9) consisted of patients with “pink” tetralogy of Fallot (arterial oxygen saturation >90%). Patients in groups 11 and III were electively scheduled for repair at about 2 months of age.

Kcsults. The postrepair peak systolic right ventricularto-peak systolic left ventricular pressure ratio did not correlate (y = 0.96) with the branch pulmonary artery size. One patient died 2 months after operation, despite good hemodynamics, of uncontrollable diffuse subcutaneous edema due to familial distichiasis lymphedema syndrome. There were no late deaths. At a median follow-up of 19 months, 1 patient underwent balloon dilation of branch pulmonary arteries. Follow-up echocardiography revealed a 30 to 60 mm Hg right ventricleto-pulmonary artery gradient in 3 patients. Co71clusions. Excellent early and midterm results can be accomplished with routine primary repair of tetralogy of Fallot in early infancy regardless of age, symptomatic status, coronary anatomy, and the size of branch pulmonary arteries as long as they arborize normally. (Ann Tl?ornc Sllrg 1995;60:S592-6)

T

repair very early in life [7], we have taken the approach that routine repair should be accomplished in the neonatal or early infancy period in all patients with TOF whether symptomatic or not, thereby offering the many advantages of early physiologic correction to all patients tvith TOF.

etralogy of Fallot (TOF) na\ the first cvanotic congenital cardiac lesion to be treated with surgical intervention. Since the first Blalock-‘Taussig shunt in 1945, the philosophy of management of TOF has undergone considerable change. With the development of cardiopulmonary bypass techniques, repair rather than palliation became the goal; however, tofal repair Mas deferred until later childhood. With expericncc and improvements in cardiopulmonarv bvpass techniques and myocardial protection, repair in earlv childhood became common. Subsequently, primary repair in infancy in symptomatic patients was advocated by some II, 21. However, e\ren today many recommend initial palliation in the neonatal or early infancy period in svmptomatic patients and in patients with anomalous I& anterior descending coronary artery or hypoplastic pulmonary arteries. Reports from some centers indicate that primary- repair can be performed safely in neonates and young infants [s-6]. These experiences, however, invol\,t ielected patients, ie, those who are symptomatic and demand earlv inter\,ention. Influenced bv the adxantageh observe> in those selected symptomatic patients M ho rcct4ved primark

Patients

and Methods

From Julv 1992 through March 1995, 30 consecutive neonates with TOF who were referred to one of us (F.L.H.) were included in this report. Any patient who was initially palliated (by other surgeons/elsewhere) was excluded from this study. The patients were divided into three categories: group I (n = 10) consisted of patients w.ith duct-dependent TOF with or without pulmonary atresia but with normal pulmonary artery (PA) arborization; group II (n = 11) consisted of patients with TOF who Lvere considered to have adequate pulmonary blood flow with systemic arterial oxygen saturation of 75% to 90%; and &up III (n = 9) consisted of patients with “pink TOF”, ie, patients with systemic arterial oxygen saturation of 90’!;, or greater. Group I patients were repaired in the neonatal period. Group II and III patients were electively scheduled for repair at about 2 months of age. liowever, patients in groups II and III were repaired

SSDl

0003-4975/95/$9.50 0003.4975(95)00732-6

Ann Thorac 5urg 1995;60:5592-6

Variable Age (days) Weight (kg) BSA (m’) Branch pulmonary artery size Right PA diameter (mm) Left PA diameter (mm) PA size index (mm’lm’)

ROUTINE

CASTA&‘EDA FESTSCHRIFT EARLY REPAIR OF TETRALOGY

S593

REDDY ET AL OF FALLOT

Group I (Duct-dependent TOt I

Group II (Cyanotic TOF)

Group III (Acyanotic TOF)

8 (4 to 27) 2.95 (1.8 to 4.1) 0.20 (0.15 to 0.24)

62 (19 to 90) 4.25 (2.4 to 5.8) 0.23 (0.19 to 0.31)

63 (41 to 90) 4.8 (3.8 to 6.1) 0.3 (0.22 to 0.31)

3.15 (3.0 to 5.5) 3.65 (2.5 to 5.0) Y4.3 (58.9 to 237.0)

earlier if they became svmptomatic (progressive cyanosis, cyanotic spells, or failure to thrive) before the scheduled date of operation. Diagnosis was established in all patients by echocardiography. Cardiac catheterization cvas performed in 8 patients with small branch PAS or suspected anomalous coronary arteries, aortopulmonnr\ collaterals, or other associated lesions. The demographic characteristics of the patients are summarized in Table 1. The median age of the patients for the whole group was 53 days (range, 4 to 90 days). The median weight at operation for the whole group was 4,100 g (range, 1,800 to 6,100 g), and the median body surface area was 0.23 m’ (range, 0.15 to 0.31 m2). There were 23 full-term and 7 premature infants. The median gestation period of premature infants was 34 weeks (range, 28 to 36 weeks). The morphologic characteristics and the associated lesions are summarized in Table 2. Size of the branch pulmonary arteries and the pulmonary artery size index [S] are summarired in Table 1. Two patients had large aortopulmonary collaterals with dual supply from normally arborizing native PAS. Two patients had associated atrioventricular canal malformation (complete in 1 patient and transitional in 1 patient), and I patient had discontinuous branch pulmonary arteries with the left PA arising from the patent ductus arteriosus. Five patients in group I had pulmonarv atresia.

Standard neonatal and infant technique5 of monitoring and cardiopulmonary bypass were emploved. Moderate to deep hypothermia with low-flow bypass was the most common approach (n = 27). Circulatory arrest was used early in the experience in 3 patients. The ventricular septal defect was closed with a glutaraldehyde-treated autologous pericardial patch in all patients. A cryopreserved valved allograft conduit was used in 5 patients with pulmonary atresia (all in group I). In all these patients a tongue-shaped extension of the homograft was used to patch the proximal leff PA bevond the ductus insertion site. A transannular patch ~.a; placed in 18/30 (60%) patients (group I, 5/S patients with pulmonaq stenosis; group II, 9/11 patients; group III, 4/Y patients). Transventricular repair with preservation of the annulus

4.5 (3.0 to 7.0) 4.5 (3.0 to 8.0) 126.2 (61.5 to 328.9)

5.0 (3.0 to 8.0) 5.0 (3.0 to 8.0) 158.4 (48.8 to 419.1)

was performed in 2 patients (2/9; 22%) in group II. Transatrial-transpulmonary repair with preservation of the native annulus was performed in 5 patients (5/9; 56%)

\/‘ariahle Preoperative status Prostaglandin E, Ventilator support [notropic agents Progressive cyanosis/ spells Failure to thrive Asvmptomatic RVO7 obstruction Pulmonary atresia I’ulmonar* stenosis Ventricular heptal defect Conovcntricular outlet AV canal Additional mt~scular VSD Coronary anomalies .Ano&lous LAD Large conal branch A~soctatrd defects Disiontinuous PAS .As.sociated svndromes Down’s s\,ndrome L’ATER Distichiasi5 Ivmphedema

Group I (n = 10) (Ductdependent TOF)

Group II (n = 11) (Cyanotic TOF)

Group III (n = 9) (Acyanotic TOF)

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0

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5 4

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0

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.A\ at~ir)ventricular; LAD = left .nterior descending coronq Jrtur,, IWOr right wntricular outflow tract; TOF = tetralogy I ‘lllot: \ kl ER =~ vertebral defects, anal atresia, tracheoesophageal hdula l\lth csophagral atrrsia, and radial and renal anomalies.

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in group 111. In nconate~, the tran~annular patch was extended onto the proximal I~ft putmonarv arterv and just across the orifice ot the r-ight pulmo&ry art&. In other patient5 who receivcld a transannular patch, branch pulmonary arterioplahty \\a\ pc,rformed if there ~a\ echocardiographic or intraop~rati1.e evidence of branch PA stenosis. In the patit>nt M,ith discontinuous branch PAS, the left PA \z’a> implantc,d dircctlv into the side ot the main PA after rehestion of the ductaj tissue. In 1 other neonate, the left PA was directlv implanted into the main PA to correct the unfa\.orablc hngulation of the left PA. Atrioventricular canal malformations were repaired in 2 patients (group II, 1; group III, I ). Large aortopulmonar\ collaterals were ligated in 2 patients (group 1, 1; group II, 1). Adequacv ot thy repair ~\a\ a+essed bv direct presyurc measurement and oximetrv in all patients, and bv intraoperative transesophagcat t,chocardiographv in patient\ weighing more than 3 kg. In 2 patients, bypass was reinstituted to revise the transannular patch duu to unacceptable residual right \,cntricular (I&‘) to PA gradents and peak RV to peak s\,stt,mic arter\ prehverc placed Iright and left atrial, 30 patients; PA, 28 patients). Postopt~ratively right atrial and PA oxygen saturations and I<\! to PA pullback gradients were obtained and postoperative I’RL.:PI 1’ was calculated. Before discharge from the hospital, L,chocarcliogr,lyh~ was performed in all patients Follow-up was complctc in all patients, and the data included clinical status, mttidication, echocardiograph\,, and reintervcntions. FOIICM -up \\a\ obtained bv direct physician and parent contact Results The mean i htandard de\,iation po\trtlpair PI<\xPI \ ratio obtained in the operating room u a\ 0.38 + 0.13 (range, 0.27 to 0.80). The intraopcrati\,r I%\ :I? \ did not corretatc (linear regression: I 0.127; 1' \ Jlut' 0.95) with the preoperative pulmonar\ artt’r\, \iLt, index (Fig 1). The absolute mean - standard dL%viation peak svxtolic right ventricular pressure ~zas 32.5 X.8 mm Hg (range, 20 to 52 mm Hg). The I’R\:~‘I I ratio obtained in the intensi\,t> care unit (mean I standard dt>\ iation, 0.13 0.13; ran,qc, 0.30 to 0.75) bvas significantI\ Io\ler than thy intraopcr,1tive PKv:I’l \ ratio (I’ 0.0’15 b\ paircbd f test). PeJ%JjWJI?fiiY’

Golf

Surg 1995;6o:S592-6

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There wcrc no periopcrati\e death\. Once patient (group I) had development of complctr heart block and required a permanent pacemakc,r. I)t~la\~c~d sternal closure M ;a~, performed in 3 patient5 (group i, 2; group III, 1) ct,ithout event. Prolonged pleural cfiu5ioni ( 7 da\,s) drveloped in 2 patient5 (group I, 1; group II, Il. Transient atrial or junctional arrhythmia’, clc\~t~lopkd in 5 patittnts (group I, 1; group II, 2; group Ill, 2). One patient (group III) underwent rc~t~uploration tar blet~ding. In 1 patient (group Ill) in whom <.irt.uIator\ arrca
1.0 .9

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opcrati\,e seizures developed. Right phrenic nerve paralv\is dev~toped in I patient (group 1) and necessitated plication of the diaphragm. The median duration of mechanical ventilation was 3 days (range, 1 to 14 days) and the median stay in the inteniive care unit was 5 days (range, 2 to 33 days). Hospital discharge occurred after a mt>dian of 10 days (range, 4 to 43 days) after operation. Echocardiography was performed at the time of discharge in all patients. A trivial residual ventricular septal dt+rct ~‘as present in 2 patients (group I, 1; group 11, l), and an additional tiny muscular ventricular septal defect ‘I\~L, prta\ent in 1 group I patient. A mild RV to PA gradient (10 to 30 mm Hg) was present in 10 patients (group 1, 3; group 11, 3; group III, 4). Pulmonary insuffi\.ic‘iicy was trivial to none in 11 patients (group I, 4; group II, -I; group Ill, 3), mild in 12 patients (group I, 5; group II, 4; group III, 3), and moderate in 7 patients (group I, 1; group II, 3; group III, 3). Tricuspid regurgitation was tri\ ial to none in 17 patients (group I, 6; group II, 5; group Ill, h), mild in 10 patients (group I, 3; group II, 5; group III, 2), and moderate in 3 patients 1 I in each group).

I-he onI!, death in this series occurred in an infant who undcrwt~nt repair at 60 days of age. This infant also had a rart’ familial lymphatic hypoplasia syndrome called di\tichiasis lvmphedema syndrome 191. In this patient, thta postrcpajr Pw:Prv was 0.5. The peak RV pressure wa\ 35 mm Hg and the right and left atria1 pressures averaged 5 and 7 mm Hg. In spite of these hemodynamic\ the postoperative course was complicated by persistint large pleural and pericardiat effusions. Recatheterilation at 1 month after operation revealed a PRV:PLV of 0.66 and no significant residual defects. The peak systolic I<\’ pressure was 44 mm Hg, and the right and left atria1 prt’~surc~ were 3 and 4 mm Hg, respectively. The patient \v;l~~ recxplor~d and bilateral pleurodesis was performed aftr’r ligation of mediastinal lymphatics. The pleural

Ann

Thorac

Surg ROC’TINE

1995:60:5592-h

Group I (n = 7)

Result Residual VSD Tricuspid regurgitation None Mild Moderate Pulmonary insufficiency None Mild Moderat? Free RV-PA gradient None Mild (c.30 mm Hg) Moderate (30 to 60 mm Hg)

(Ductdependent TOF)

Group

II

(n =- IO)

(Cyanotic TOF)

0

0

4

1

3

i

0

Group

8)

(Acyanotic TOF) 0

Tutal (n 25) 0

I

2

2 (iv,>)

4

13 (52"t

REDDY ET AL OF FALLOT

S595

patch has a 60 mm Hg supravalvar gradient. The patent in group Ill who received a transatrial-transpulmonary repair has a gradient of 42 mm Hg across the annulus. In addition, 2 patients have gradients from main PA to branch PAS. In 1 group I patient with reimplantation of the left PA into the main PA a 32 mm Hg gradient was detected. The patient in group II who underwent two previous balloon dilations of branch PAS has a gradient of 40 to 50 mm Hg from main PA to the branch PAS. At a median clinical follow-up of 18.5 months (range, 2 to 32 months), all patients were asymptomatic and only 2/29 patients (7%) were receiving cardiac medication. Actuarial survival at 32 months was 96.7 months, and actuarial freedom from reintervention was 90.4% at 32 months.

111

(n

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effusions were successfully eliminated bv pleurodesis. However, uncontrollable diffuse subcutdneous edema then developed to the point where ventilation was compromised.

Follow-up Follow-up was obtained in April lYY5 and was complete in all patients. There have been no late deaths. Reintervention was performed in l/29 patients (3.4%). This patient’s pulmonary artery index at repair was 61.5 mm2/m2 and the postrepair I’Rv:I’L 1’ ratio was 0.80. Follow-up echocardiography was indicative of high RV pressure. Cardiac catheterization at 12 months after repair showed small branch pulmonary arteries with a PRVPLV ratio of 1.0 to 1.20. Balloon dilation of both right and left PAs was performed and the size of both branch PAS increased from 3 to 3.5 mm to 7.0 mm in size. Balloon dilation was repeated after 6 months. A subsequent catheterization showed that RV pressure has remained subsystemic with a PR~:PLL ratio of 0.80. However the pat&t has angiographic evidence of abnormal lobar and segmental pulmonarv arteries. In 25/29 surviving patients echocardiographic evaluation was performed at a median of 12 months (range, 2 to 28 months) after operation. The findings are summarized in Table 3. No patient has a residual ventricular septal defect or a residual atria1 level shunt. Three patients (1 in each group) have moderate RV to 1’A gradient. The patient in group I has a 54 mm Hg across the allograft conduit. The patient in group 11 who received a tranventricular-transpulmonary repair without a transannular

Comment After five decades of surgical management of TOF there are still a number of unresolved issues. Uncertainty remains regarding both the timing and the ideal form of early management. The logic we have used to support our current approach of elective primary repair in early infancy regardless of symptoms or morphology is as follows. First, TOF, unlike other defects such as ventricular septal defect, will require surgical intervention in all cases. As a result, operation cannot be avoided by waiting, Second, the potential advantages of early primary repair are many [7]. The RV is not subject to ongoing pressure overload and subsequent RV hypertrophy and its consequences. The cardiovascular physiology will be normalized, thereby avoiding the consequences of continuing hvpoxemia and risk of cyanotic spells. Also, the problems~ associated with palliative procedures such as shunt obstruction/occlusion, PA distortion, volume overload of the left ventricle, and potential for the development of pulmonary vascular obstructive disease are avoided. Early repair may also be beneficial to pulmonary angiogenesis and alveologenesis in patients with decreased lung perfusion. Those who argue for early palliation do so because they believe the morbidity and mortality of early primary repair outweighs these potential advantages. The actual txxperiencr with early primary repair from this study and others suggests that age of repair is not an immutable risk factor for mortality [7, lo]. Morbidity is more difficult to assess, especially because all other reports of early repair have selected a subset of patients with the most severe symptoms and the most complex RV outflow tract morphology. Considering the selection of high-risk patients, morbidity and mortality both have been quite favorable in these series. We reason that morbidity and mortality will be even more favorable if all patients, including those with more favorable morphology, receive carlv primary repair. Shme who’ advocate the policy of palliating symptomatic infants and delaying repair in asymptomatic infants argue that such an approach will result in a decreased incidence of transannular patching and the consequences of free pulmonary regurgitation. Such a conclu-

Ann Thorac Surg 1995;60:5592-6

sion will be validated only it a cohort of patients with delayed repair of POF is followed up from birth and compared with a similar cohort repaired early in infancy, Retrospective analysis will not account for patients who have been lost to follow-up, died after palliation or while awaiting total repair, or been found to be unsuitable fol repair. It is our belief that the need for transannular patching reflects the severity of RV outflow tract obstruction at the annular level. Consequently, symptomatic patients selected for repair in the neonatal period generally have pulmonary atresia or severe pulmonary stenosis and have received transannular patching because of the morphology, not because of their age. Asymptomatic patients or patients with pink TOF‘ generally have less severely obstructed RV outflow tract morphology, and the need for transannular patching is predicted to be lower. The present series confirms this point, demonstrating that if the morphologv is favorable, avoidance of transannular patching can be.readil>, accomplished even when repair is undertaken in early infancy. In our experience, early repair also minimizes the amount of RV infundibular muscle that must be resected to relieve RV outflow tract obstruction. The present series also refutes the concern that patient\ with small branch PAS need a shunt to alloM, growth of the branch PAS before complete repair. Our data indicate no correlation between l’~~v:l’~v ratio and branch PA size as long as thta distal PAS arbori7e normall). The PRL:PI L’ ratio itself must also be reassessed as a clinical indicator of outcome in this different patient population. This ratio has been correlated with outcome; however, the great majoritv of patients used to develop this correlation have been patients repaired later in life. Small infants may have slightly higher intrinsic pulmonarv vascular resistance (although physiologically based an> not due to disease) than some older patients, and the pulmonary vascular resistance will decrease over time. Additionally, neonate5 and infants are likelv to have lower systemic vascular resistance. As a result the PI<\:PI \ ratio mav be higher even although the absolute peak svstolic RV pressure is relatively low (usuallv 20 to 40 mm Hg). Ultimately, the PRv:PLv ratio is likeli to decrease as pulmonary vascular resistance falls and svstemic vascular resistance rises with time. Reintervention in the neonates \\,ho received conduits

is inevitable. In addition, some patients may require reintervention for the management of distal PAS either due to inadequate growth of branch PAS or due to surgical residua. However, there is no evidence that reintervention is more likely after early repair. Long-term follow-up will be necessary to settle this issue. In summary, primary repair of TOF can be accomplished in the neonatal and early infancy period regardless of the symptomatic status, PA size (as long as distal PAS arborize normally), and coronary anatomy, with excellent early and midterm results. This approach also avoids palliation and minimizes the number of operations. Long-term follow-up is necessary to determine whether such an approach will be associated with any disadvantages.

References 1. Castancda AR, Freed MD, Williams RG, Norwood WI. Repair of tetralogy of Fallot in infancy. J Thorac Cardiovasc Surg 1977;74:372-81. 2. Starr A, Bonchek Ll, Sunderland CO. Total correction of tetralogy of Fallot in infancy. J Thorac Cardiovasc Surg 1973;65:45-57. 3. Sousa L’va M, Lacour-Gayet F, Komiya T, et al. Surgery for trtralogy of Fallot at less than six months of age. J Thorac Cardiovasc Surg 1994;107:7291-300. -t. DiDonato RM, Jonas RA, Lang I’, Rome JJ, Mayer JE, Castafieda AR. Neonatal repair of tetralogy of Fallot. J Thorac C‘ardiovasc Surg 1991;101:126-37. T. tiennein H.4, Mosca RS, Urcelay G, et al. Intermediate rt,sultb after complete repair of tetralogy of Fallot in neonates. I Thorac Cardiovasc Surg 1995;109:332-44. 6. I’ouati GD, Vouhc PR, Amodeo A, et al. Primary repair of tetralogv of Fallot in infancy. J Thorac Cardiovasc Surg 199O;YY:396-403. 7. C‘a\taiitlda AR, Jonas RA, Mayer JE, Hanley FL. Cardiac \urger\ of the neonate and infant. Philadelphia: Saunders, 1994:215-34. 8. I\akata S, lmai Y, Takanashi Y, ct al. A new method for the cluantitative standardization of cross sectional areas of the pulmonary arteries in congenital heart disease with decreased pulmonary blood flow. J Thorac Cardiovasc Surg lY84;8H:IilO-9.

9. Trmplt~ IK, Collin JR. Distichiasis lymphedema syndrome: a family report. Clin Dysmorph 1994;3:139-42. IO. Kirklin IW, Blackstone EH, Jonas RA, et al. Morphologic and surgical determinants of outcome events after repair of tctralogv of Fallot and pulmonary stenosis. A two institution \tudv. J Thorac Cardiovasc Surg 1992;103:706-23.