Early Primary Repair of Tetralogy of Fallot

Transcription

1 ORIGINAL ARTICLES Erly Primry Repir of Tetrlogy of Fllot Robert A. Gustfson, M.D., Gordon F. Murry, M.D., Herbert E. Wrden, M.D., Ronld C. Hill, M.D., nd G. Edwrd Rozr, Jr., M.D. ABSTRACT Young ge, low weight, nd the requirement for trnsnnulr ptch reconstruction of the right ventriculr outflow trct (RVOT) re thought to dversely ffect intrcrdic repir of tetrlogy of Fllot. Forty ptients underwent complete repir between Jnury, 1984, nd Jnury, Only infnts with pulmonry tresi, complete trioventriculr cnl, or coronry rtery nomlies were shunted initilly. The mllignment ventriculr septl defect ws closed with Dcron ptch. Infundibulr resection ws minimized. All tril communictions were left open. Thirty-four ptients (85%) hd trnsnnulr RVOT ptch, nd 2 ptients (5%) hd nontrnsnnulr ptch. All 10 infnts weighing 3.4 to 9.6 kg hd trnsnnulr RVOT ptch t 7 weeks to 12 months of ge. An RVOT ptch ws used in 26 of 30 children operted on between 1 nd 6 yers of ge (medin ge, 24 months). No ptient undergoing intrcrdic repir died. Postopertive RVOT pullbck grdients were between 0 nd 35 mm Hg (men, 18.5 mm Hg). Postopertive pulmonry rtery sturtion (men, 73%) did not revel ny residul ventriculr septl defect. The right ventriculdrteril pressure rtio ws lwys less thn 0.6 (men, 0.4). All children re doing well t follow-up from two to 37 months. Seril echocrdiogrms revel no residul ventriculr septl defect nd only 1 moderte RVOT grdient. Follow-up crdic ctheteriztion in 15 ptients reveled no residul ventriculr septl defect nd RVOT grdients between 5 nd 35 mm Hg. The right ventriculr/left ventriculr pressure rtio ws lwys less thn 0.6 (men, 0.48). The erly nd lte results justify continued primry repir of tetrlogy of Fllot in symptomtic children, regrdless of ge or weight. A trnsnnulr RVOT ptch did not hve mjor impct on opertive mortlity. Since Lillehei nd collegues [l] reported the intrcrdic repir of tetrlogy of Fllot in 1954 using controlled cross-circultion, the morbidity nd mortlity of repir hve progressively declined with mjor dvnces in crdic surgicl techniques, postopertive intensive cre, nd crdic nesthesi [2, 31. Mny centers still dvocte n initil ortopulmonry shunt for young ptients with tetrlogy of Fllot who need n opertion From the Division of Crdiothorcic Surgery, Deprtment of Surgery, West Virgini University Medicl Center, Morgntown, WV. Presented t the Twenty-third Annul Meeting of the Society of Thorcic Surgeons, Toronto, Ont, Cnd, Sept 21-23, Address reprint requests to Dr. Gustfson, Deprtment of Surgery, West Virgini University Medicl Center, Morgntown, WV in the first few yers of life, followed by intrcrdic repir. Initil ortopulmonry shunts in infnts re not without mrked morbidity nd mortlity [4, 51. The selective use of primry repir in infnts hs been reported, but the criteri to determine optiml cndidtes for initil pllition versus complete repir in young children remin uncler [6, 71. Stimulted by the excellent results of Brrtt-Boyes nd Neutz [8] nd Cstned nd collegues [9] with primry repir in infncy, we dopted policy in 1984 of erly repir in ll infnts nd children with symptomtic tetrlogy of Fllot, regrdless of their ge or weight. Recently, trnsnnulr ptch reconstruction, ge, nd weight hve been implicted s independent risk fctors for erly primry repir [6, 101. In n effort to clrify the role of these risk fctors, we reviewed ll ptients who hd undergone repir of tetrlogy in our center since Ptients nd Methods From Jnury, 1984, to Jnury, 1987, t our center 40 consecutive ptients underwent primry repir of symptomtic tetrlogy of Fllot. Thirty boys nd 10 girls rnged in ge from 7 weeks to 6 yers nd weighed 3.8 to 24 kg (men weight, 10.8 kg). Ten ptients were less thn 1 yer of ge. The medin ge of the other 30 ptients ws 24 months. Thirteen ptients hd ssocited crdiovsculr lesions (Tble 1). lndictions for Opertion Erly repir in infncy ws performed for hypoxic spells in 5 ptients nd severe cynosis with hemoglobin concentrtion of 19 to 20 gddl in 5 ptients. In the 30 children over 1 yer of ge, the indiction for primry repir ws hypoxic spells in 5 ptients nd progressive cynosis in 25 ptients. Every ttempt ws mde to electively repir ll ptients by ge 2 yers. Ptients older thn 2 yers t initil presenttion were referred for primry repir t tht time. All ptients underwent repir s indicted without regrd to ge, weight,. or brnch pulmonry rtery size. Contrindictions to erly repir in infncy were pulmonry tresi, complete trioventriculr cnl defect, nd nomlous origin of the left nterior descending coronry rtery from the right coronry rtery. Only these ptients underwent n initil pllitive shunt procedure. Ptients with cynotic tetrlogy of Fllot with net left-to-right shunt nd n rteril sturtion greter thn 93% were excluded from this study. Surgicl Technique Profound hypothermic circultory rrest, with surfce cooling nd extrcorporel core cooling nd rewrming, 235 Ann Thorc Surg 45: , Mr Copyright by The Society of Thorcic Surgeons

2 ~~ ~~~ ~ 236 The Annls of Thorcic Surgery Vol45 No 3 Mrch 1988 Tble 1. Associted Crdiovsculr Defects Defect No. of Ptients Age (mo) Right ortic rch Bicuspid ortic vlve 1 46 Subortic stenosis 1 35 Left superior ven cv Absent left pulmonry rtery 1 18 Secundum ASD ASD = tril septl defect ws used for opertions in infnts nd ptients less thn 10 kg (18 ptients). Stndrd crdiopulmonry bypss with systemic hypothermi to 25 C ws the technique used in older children. Myocrdil protection ws ccomplished by cold potssium crystlloid crdioplegi nd topicl hypothermi. Myocrdil tempertures were mesured in the perfusion group, nd dditionl crdioplegi ws given s necessry to mintin myocrdil temperture less thn 16 C. Hypothermic circultory rrest ws used in the 3 ptients with persistent left superior ven cv drining into the coronry sinus. The intrcrdic repir ws performed through verticl incision in the right ventriculr outflow trct (RVOT) prllel to the left nterior descending coronry rtery. If the pulmonry vlve nnulus or min pulmonry rtery ws hypoplstic, the incision ws crried cross the pulmonry vlve nnulus to the bifurction of the min pulmonry rtery. The nnulr incision crossed the commissure between the nterior nd right pulmonry vlve cusp. If stenosis of the origin of the left pulmonry rtery ws present, the incision ws continued onto the left pulmonry rtery. A pulmonry vlvotomy ws performed through the min pulmonry rtery if the pulmonry vlve nnulus ws not hypoplstic. The infundibulr incision ws extended cross the 0s infundibuli onto the trbeculr portion of the right ventricle. Only lrge hypertrophied infundibulr muscle bundles were resected. Infundibulr resection ws minimized in infnts who required trnsnnulr ptching. No ttempt ws mde to "scoop out" the floor of the infundibulum. The lrge mllignment type of ventriculr septl defect ws closed with Dcron ptch using interrupted pledgeted sutures. In 34 ptients the RVOT ws closed with trnsnnulr ptch (Tble 2). A nontrnsnnulr RVOT ptch ws used in 2 ptients, nd the right ventriculotomy ws primrily closed in 4 ptients. One ptient who ws found to hve n unrecognized left nterior descending coronry rtery rising from the right coronry rtery underwent extensive infundibulr resection nd primry closure of the ventriculotomy. A ptient with n bsent left pulmonry rtery hd trnsnnulr ptch extending onto the right pulmonry rtery. The tril septum ws usully inspected. A ptent formen ovle ws not closed. Atril septl defects of the secundum Tble 2. Outflow Trct Reconstruction Age No Ptch RV Ptch RV-PA Ptch <1 yr (100%) >1 yr 4 (13%) 2 (7%) 24 (80%) Totl 4 (10%) 2 (5%) 34 (85%) RV = right ventriculr; PA = pulmonry rtery. type were primrily closed in 2 ptients. The ductus rteriosus ws ligted before cooling in ptients who underwent hypothermic circultory rrest. One ptient lso hd resection of discrete subortic stenosis through the scending ort. Right tril, left tril, nd min pulmonry rtery ctheters were inserted to improve postopertive monitoring nd ssist in better fluid mngement. These ctheters were lso used to determine intrcrdic shunts nd to mesure right ventriculr (RV)-pulmonry rtery grdients in the immedite postopertive period. Temporry tril nd ventriculr pcemker electrodes were lso plced. FOllOW-up Echocrdiogrms were obtined on ll ptients in the erly postopertive period nd just before dischrge. Subsequently, seril echocrdiogms were performed t six-month intervls. All ptients were seen by n ttending peditric crdiologist t three-month intervls; chest roentgenogrm nd n electrocrdiogrm were obtined on those visits. Crdic ctheteriztion ws recommended t one yer fter repir. Results RVOT Reconstruction Of the 40 ptients, 34 (85%) hd hypoplsi of the pulmonry vlve nnulus or the min pulmonry rtery, or both. A trnsnnulr pericrdil ptch ws used to relieve the RVOT obstruction. All 10 infnts weighing 3.8 to 8.6 kg hd trnsnnulr ptching. In 2 ptients (5%), nontrnsnnulr RV ptch ws sufficient to relieve the outflow obstruction. Infundibulr resection nd primry closure of the ventriculotomy were dequte in 4 ptients (10%) (Tble 2). All ptients under 24 months of ge required trnsnnulr ptch (Fig 1). A nontrnsnnulr ptch or primry ventriculotomy closure ws possible in 6 of the 20 ptients (30%) older thn 24 months. Figure 2 summrizes the incidence of outflow trct ptching with regrd to weight. All 19 ptients weighing less thn 10 kg hd trnsnnulr ptch reconstruction. Postopertive Complictions All infnts received digitlis nd diuretics following repir. Continuous infusion of dopmine in the renl rnge of 2 to 4 pg/kg/min ws frequently used in the first 24 hours fter opertion (60% of totl group). Only 3 infnts required ventiltory support beyond 48 hours.

3 237 Gustfson et l: Erly Repir of Tetrlogy of Fllot 15 0 Trnsnnulr Nontrnsnnulr =No ptch < )4 YEARS Fig 1. Use of right ventriculr outflow ptches ccording to ge of ptients t time of opertion O r E E - c n > 10 z c m e 0 Highest Lowest UI c._ 0 * n 15 1c C 0 Trnsnnulr Nontrnsnnulr k9 Fix 2. Use of right ventriculr outflow ptches ccording to weight ofptients t time of opertion. No ptient sustined neurologicl deficit. Seril electrocrdiogrms reveled right bundle brnch block pttern in 90% of the ptients. No ptient sustined surgicl complete hert block. Erly Hernodynmic Results Hemodynmic nd oximetric studies were obtined 48 hours fter opertion in ll ptients, using the intrcrdic ctheters plced t repir. Simultneous right tril nd min pulmonry rtery oxygen sturtions were compred to identify ny residul ventriculr septl defects. The min pulmonry rtery sturtions rnged from 68 to 77% (men, 73%). No mrked hemodynmic shunt cross the ventriculr septum ws identified. The immedite postopertive RVOT grdient ws obtined 48 hours following opertion. The right ventricle to rdil rteril pressure rtio ws lso clculted. The erly RVOT grdient rnged between 0 to 30 mm Hg (men, 15 mm Hg; Fig 3). The trnsnnulr ptch group vried between 0 to 25 mm Hg (men, 12 mm Hg). The nontrnsnnulr ptch group vried between 10 to 20 mm Hg (men, 15 mm Hg), nd the primry ventriculr closure group rnged between 5 to 30 mm Hg (men, 14 mm Hg). Tble 3 summrizes the erly hemodynmic results ccording to the degree of residul pulmonry outflow trct obstruction. The RV/rteril pressufe rtio rnged between 0.31 to 0.58 (men, 0.41). There ws no Tble 3. lrnrnedite (48 hours) Outflow Trct Grdient Trivl Mild Moderte Ptch (G14 (15-39 (>40mm Plcement mmhg) mmhg) Hg) Totl None 3 (75%) 1(25%) 0 4 RV ptch 1(50%) 1(50%) 0 2 RV-PA ptch 27 (79%) 7 (21%) 0 34 Totl 31 (78%) 9 (22%) 0 40 RV = right ventriculr; PA = pulmonry rtery. difference in the rtio ccording to the type of RVOT reconstruction. Erly postopertive echocrdiogrms did not revel ny residul ventriculr septl defects or mrked residul pulmonry obstruction. Lte Hernodynmic Results Of the 40 ptients, 15 (37%) hve undergone postopertive crdic ctheteriztion between one nd two yers following repir. No residul ventriculr septl defects were identified by oximetric studies or left ventriculogrphy. No pulmonry rtery neurysms were found. The degree of pulmonry insufficiency ws estimted by the technique reported by Oku nd collegues [ll]. The 3 ptients with no outflow trct ptches hd no pulmonry insufficiency. The 2 ptients with nontrnsnnulr ptches hd only Grde 1 (mild) pulmonry insufficiency. The 10 ptients who hd trnsnnulr ptch reconstruction hd either Grde 1 or Grde 2 (moderte) pulmonry insufficiency. In the trnsnnulr group, the RV-pulmonry rtery grdient rnged between 10 to 37 mm Hg (men, 22 mm Hg; Fig 4). The rnge for the nontrnsnnulr ptch group ws 12 to 18 mm Hg (men, 15 mm Hg), nd the rnge for the group undergoing primry closure ws 12 to 45 mm Hg (men, 24 mm Hg). The ptient with the 45 mm Hg grdient hd the unrecognized left nterior descending coronry rtery from the right coronry rtery. The RV/left ventriculr rtio ws between 0.31 to 0.60 (men, 0.45) in the trnsnnulr ptch group, 0.32 to 0.36 (men, 0.34) in

4 ~~ ~ 238 The Annls of Thorcic Surgery Vol 45 No 3 Mrch o 50 I E - 40 c Q e 2 30 n I 20 > Tble 4. Lte Outflow Trct Grdients t Rectheteriztion Highest Lowest Trivl Mild Moderte Ptch (0-14 (1539 (>40mm Plcement mmhg) mmhg) Hg) Totl None 2 (67%) 0 1(33%) 3 RV ptch 1(50%) 1(50%) 0 2 RV-PA ptch 2 (20%) 8 (80%) 0 10 Totl 5 (33%) 9 (60%) 1(7%) 15 RV = right ventriculr; PA = pulmonry rtery. the nontrnsnnulr ptch group, nd 0.34 to 0.54 (men, 0.42) in the no ptch group. Tble 4 summrizes the degree of postopertive pulmonry outflow stenosis in the rectheteriztion group. Opertive Results No ptient died following primry repir of symptomtic tetrlogy of Fllot. All ptients remin symptomtic over follow-up from 2 to 37 months. Seril electrocrdiogrms continue to show sinus rhythm in ll ptients. No ptient is tking ntirrhythmic drugs. Seril chest roentgenogrms do not revel ny pulmonry rtery neurysms. Seril echocrdiogrms continue to show no residul ventriculr septl defects nd only 1 ptient with moderte RVOT obstruction (ptient with left nterior descending coronry rtery from right coronry rtery). Comment The optiml mngement of infnts nd children with symptomtic tetrlogy of Fllot cn be primry repir or initil pllitive shunt procedure followed by secondry repir. Brrtt-Boyes nd Neutz [8] nd Strr nd collegues [12] in 1973 begn routine primry repir in young, symptomtic infnts nd subsequently reported better results thn those chieved with twostge pproch. Disturbed by the reported morbidity nd mortlity of pllitive procedures in infncy [4], I Cstned nd ssocites [9] proceeded to perform primry repir of tetrlogy in infnts, regrdless of ge or weight. Their opertive mortlity on the first group of infnts less thn 1 yer old ws 7.0%, comprble to the opertive risk of n initil ortopulmonry shunt procedure. Except for infnts with body surfce re less thn 0.35 m2 nd n ge less thn 6 months, Kirklin nd ssocites [lo] prefer primry repir so long s trnsnnulr ptch reconstruction is not required. Proponents of two-stge pproch emphsize the low morbidity nd mortlity of n initil ortopulmonry shunt nd the potentil for growth of the pulmonry rteries, voiding subsequent trnsnnulr outflow trct reconstruction. While Kirklin nd ssocites [lo] hve shown tht the presence of shunt did not ffect hospitl mortlity t secondry repir, Sde nd co-workers [13] hve shown tht over time systemic pulmonry rtery shunt will not usully enlrge the hypoplstic conus or pulmonry vlve nnulus or both. Fourteen of their 24 ptients who initilly underwent Wterston nstomosis needed trnsnnulr outflow ptch t the time of repir of tetrlogy. Six more ptients required vlved conduit becuse of cquired pulmonry tresi [13]. Likewise, Pcific0 nd ssocites [14] reported 71% incidence of ptch enlrgement of the pulmonry vlve ring in ptients who underwent repir fter initil Wterston shunt. Erly primry repir of tetrlogy not only voids the morbidity nd mortlity of ortopulmonry shunt procedures but over time my preserve optiml left ventriculr function. Borow nd co-workers [ 151 investigted left ventriculr function in group of stisfctorily repired tetrlogy ptients using methoxmine to increse fterlod. There ws no significnt difference in the resting crdic index, left ventriculr systolic pressure, left ventriculr end-distolic pressure, or left ventriculr minute-work index mong group of ptients who underwent repir before ge 2 yers nd group of ptients who underwent repir fter ge 2 yers. However, with fterlod stress, older ptients hd bnorml work function curves with depressed slopes. These findings rised the possibility tht erly primry repir my well preserve postopertive left ventriculr function. Vn Prgh nd collegues [16] proposed tht tetrlogy of Fllot is relly monology. The bsic nomly ppers to be underdevelopment of the subpulmonry infundibulum (conus) nd its sequele. Filure of the norml posterior inferior nd rightwrd movement of the crist suprventriculris results in poor lignment between the bnormlly locted crist bove, reltive to the normlly locted ventriculr septum, nd the septl bnd below; hence, the ventriculr septl defect in tetrlogy is due to cristl mllignment nd not to membrnous septl deficiency [16]. Anderson nd collegues [ 171 believe the common feture of infundibulr obstruction in tetrlogy is due to nterior nd cephld devition of the infundibulr septum. The resulting obstruction my be excerbted by hypertrophy of the infundibulr septum, hypertrophy of the body of the

5 239 Gustfson et l: Erly Repir of Tetrlogy of Fllot trbecul septomrginlis, or ll of these. They go on to comment tht relief of infundibulr musculr obstruction lone is often insufficient to completely relieve the RVOT obstruction [17]. Conl septl hypoplsi nd mllignment ventriculr septl defect were present in ll 41 infnts reported on by Cstned nd co-workers [9]. The re of gretest obstruction to pulmonry blood flow in the mjority of their infnts ws t the pulmonry vlve nnulus. Their findings support the concept tht mrked RV hypertrophy with tetrlogy of Fllot is secondry to outflow trct obstruction nd is progressive with ge. In recent rticle, Hmmon nd co-workers [6] reported tht diffuse hypoplsi of the pulmonry outflow trct or pulmonry tresi requiring trnsnnulr ptch reconstruction nd ge less thn 1 yer were both independent risk fctors fter repir of tetrlogy. The opertive mortlity in their infnts ws 14.3% compred with 5.6% in older children. Trnsnnulr ptch reconstruction in infnts incresed the mortlity to 15.8% compred with 0% in older children without trnsnnulr ptch. Trnsnnulr ptching ws lso n independent incrementl risk fctor in the Albm experience reported by Kirklin nd ssocites [lo]. In review of 208 children who hd repir of tetrlogy of Fllot, there ws no ssocition between opertive mortlity nd the use of trnsnnulr ptch in the Boston experience, s reviewed by Murphy nd co-workers [18]. In their infnt repir group, 70% of the ptients required trnsnnulr ptch nd 22% hd nontrnsnnulr ptch plced. Trnsnnulr ptches did not increse the opertive mortlity of erly primry repir of tetrlogy in infncy. Our experience would seem to support this observtion tht trnsnnulr ptching does not increse opertive mortlity. There were no deths in this series, which included 10 infnts nd totl of 34 ptients with trnsnnulr ptches. The results of erly nd lte postopertive evlutions fter erly primry repir re very encourging. No ptient ws found to hve residul ventriculr septl defect by erly oximetric studies or seril echocrdiogrms. A low incidence of hemodynmiclly importnt shunts cross the ventriculr septum ws lso noted by Cstned nd ssocites [9] fter erly repir. The hllmrk of tetrlogy in young children is hypoplsi of the conus nd pulmonry vlve nnulus. Secondry hypertrophy of the septl nd prietl bnds occurs over time. Therefore, extensive resection of the prietl nd septl bnds in erly repirs my weken the function of the right ventricle or predispose to residul ventriculr septl defects. Severe right hypertrophy in older ptients my mke optiml visuliztion of the mllignment ventriculr septl defect difficult. Follow-up crdic ctheteriztion in 15 ptients continued to show no residul ventriculr septl defects. The RVOT obstruction ws repired successfully in ll ptients. There ws no difference in the erly men outflow trct grdient mong the trnsnnulr ptch, nontrnsnnulr ptch, or no ptch group. The erly men RV/rteril pressure rtio did not differ mong the methods of RVOT reconstruction. The rtio ws lwys below 0.6, with men of 0.41 for the totl group. Although only 15 ptients hve hd lte hemodynmic studies, the pressure difference cross the outflow trct nd RV/left ventriculr rtio hs not incresed with time. There remins no difference between the methods of mnging the RVOT obstruction in tetrlogy of Fllot. Lte echocrdiogrms in ll ptients continue to support this observtion. Murphy nd co-workers 1, reporting on the lte hemodynmic results fter repir of tetrlogy, found tht 90% of infnts repired under hypothermic rrest hd less thn 40 mm Hg outflow grdient nd tht there ws no ssocition between the residul grdient or the RV systolic pressure nd type of RV outflow reconstruction. All ptients hve been crefully followed up with seril chest roentgenogrms. The development of neurysm of the outflow ptch hs not occurred over our short follow-up period. We, s others, believe tht neurysms develop in ptients with residul obstruction to pulmonry blood flow [9]. If by using trnsnnulr ptch, the residul outflow trct grdient cn be optimlly reduced, the risk of lte neurysm should be minimized. Opponents of trnsnnulr ptching point to the long-term risk of pulmonry insufficiency. The cretion of pulmonry insufficiency is inherent in ll methods of relief of outflow trct obstruction in tetrlogy, even pulmonry vlvotomy lone. Ellison nd collegues [19] found in experimentl nimls tht isolted pulmonry insufficiency is well tolerted over yers. Clder nd ssocites [20] found pulmonry insufficiency ws well tolerted cliniclly nd hemodynmiclly, unless there ws distl pulmonry stenosis or brnch stenosis. Using men right tril pressure s n index of RV distolic complince nd, therefore, the hemodynmic effect of pulmonry insufficiency, Murphy nd ssocites [ 181 found no significnt difference mong different methods of RVOT reconstruction fter repir of tetrlogy. Oku nd ssocites [ll] grded the degree of postopertive pulmonry insufficiency fter repir of tetrlogy from Grde 1 (trce) to Grde 4 (severe). Lte postopertive hemodynmics nd ventriculr function were excellent in ptients with mild residul pulmonry stenosis nd pulmonry insufficiency of Grde 2 or less, nd it ws poor in those with moderte residul pulmonry stenosis nd mrked pulmonry insufficiency. To prevent mrked pulmonry insufficiency, they felt tht the crosssectionl re index of the pulmonry nnulus should be 1.75 to 2.5 cm/m2 fter trnsnnulr ptch ws used [Ill. In review of the postopertive pulmonry ngiogrms from our 15 rectheterized ptients, the nontrnsnnulr nd trnsnnulr ptch group hd either Grde 1 or Grde 2 pulmonry insufficiency. We concur tht mild pulmonry insufficiency is preferble to residul outflow trct stenosis [21]. The trnsnnulr ptch should be mde only lrge enough to dequtely relieve

6 240 The Annls of Thorcic Surgery Vol45 No 3 Mrch 1988 the outflow trct obstruction. The excellent postopertive results of severl series of ptients undergoing repir of tetrlogy support the benign course of isolted pulmonry insufficiency over severl yers [ 18, 211. The hemodynmic sequele of pulmonry insufficiency over lifetime remin unknown. Our dt support the concept of erly primry repir of symptomtic tetrlogy of Fllot regrdless of ge or weight. The frequent utiliztion of trnsnnulr ptching ws not risk fctor in this smll series. Every effort must be mde to completely relieve the RVOT obstruction regrdless of the need for n outflow trct ptch. Longer follow-up will be necessry to evlute the lte consequences of mild to moderte pulmonry insufficiency nd the true incidence of ptch neurysms. References 1. Lillehei CW, Cohen M, Wrden HE, et l: Direct vision intrcrdic surgicl correction of the tetrlogy of Fllot, pentology of Fllot, nd pulmonry tresi defects. Ann Surg 142:148, Ruzyllo W, Nihill MR, Mullins CE, McNmr DG: Hemodynmic evlution of 221 ptients fter intrcrdic repir of tetrlogy of Fllot. Am J Crdiol 34:565, Pcifico AD, Brgeron LM, Kirklin JW: Primry totl correction of tetrlogy of Fllot in children less thn four yers of ge. Circultion 48:1085, Greenwood RD, Nds AS, Rosenthl A, et l: Ascending orto-pulmonry rtery nstomosis for cynotic congenitl hert disese. Am Hert J 94:14, Brbos R, Somerville J, Ross D: Aorto-right pulmonry rtery nstomosis: long-term problems nd results fter totl correction. Am J Crdiol33:125, Hmmon JW, Henry CL, Merrill WH, et l: Tetrlogy of Fllot: Selective surgicl mngement cn minimize opertive mortlity. Ann Thorc Surg 40:280, Arciniegs E, Frooki ZQ, Hkimi M, et l: Erly nd lte results of totl correction of tetrlogy of Fllot. J Thorc Crdiovsc Surg 80:770, Brrtt-Boyes BG, Neutz JM: Primry repir of tetrlogy of Fllot in infncy using profound hypothermi with circultory rrest nd limited crdiopulmonry bypss: comprison with conventionl two stge mngement. Ann Surg 178:406, Cstned AR, Freed MD, Willims RG, Norwood WI: Repir of tetrlogy of Fllot in infncy: erly nd lte results. J Thorc Crdiovsc Surg 74:372, Kirklin JW, Blckstone EW, Pcifico AD, et l: Routine primry repir vs. two-stge repir of tetrlogy of Fllot. Circultion 60:373, Oku H, Shirotni H, Sunkw A, Yokoym T: Postopertive long-term results in totl correction of tetrlogy of Fllot: hemodynmics nd crdic function. Ann Thorc Surg 41:413, Strr A, Bonchek LI, Sunderlnd CO: Totl correction of tetrlogy of Fllot in infncy. J Thorc Crdiovsc Surg 65:45, Sde R, Sloss J, Trves S, et l: Repir of tetrlogy of Fllot fter ortopulmonry nstomosis. Ann Thorc Surg 23:32, Pcifico AD, Kirklin JW, Blckstone EH: Surgicl mngement of pulmonry stenosis in tetrlogy of Fllot. J Thorc Crdiovsc Surg 74:382, Borow KM, Green LH, Cstned AR, Kene JF: Left ventriculr function fter repir of tetrlogy of Fllot nd its reltionship to ge t surgery. Circultion 61:1150, Vn Prgh RV, Vn Prgh S, Nebesr RA, et l: Tetrlogy of Fllot: underdevelopment of the pulmonry infundibulum nd its sequele. Am J Crdiol 26:25, Anderson RH, Allwork SP, Ho SY, et l: Surgicl ntomy of tetrlogy of Fllot. J Thorc Crdiovsc Surg 81:887, Murphy ID, Freed MD, Kene JF, et l: Hemodynmic results fter intrcrdic repir of tetrlogy of Fllot by deep hypothermi nd crdiopulmonry bypss. Circultion 62:Suppl 1:168, Ellison RG, Brown WJ Jr, Yeh TJ, Hmilton WF: Surgicl significnce of cute nd chronic pulmonry vlvulr insufficiency. J Thorc Crdiovsc Surg 60:549, Clder AL, Brrtt-Boyes BG, Brndt PWT, Neutze JM: Postopertive evlution of ptients with tetrlogy of Fllot repired in infncy. J Thorc Crdiovsc Surg 77:704, Finnegn P, Mider R, Ptel RG, et l: Results of totl correction of the tetrlogy of Fllot. Br Hert J 38:934, 1976 Discussion DR. JOHN w. HAMMON (Nshville, TN): I congrtulte Dr. Gustfson nd his collegues on their excellent series of ptients with tetrlogy of Fllot treted with primry correction. Their 0% opertive mortlity is gol to which ll of us should spire. Although these dmirble results re open to gret discussion, I would like to exmine some of the fctors tht my hve contributed to the low mortlity nd to criticlly exmine the series in this light. First, this is smll series, with less thn 50 ptients, which does not diminish the 0% operting mortlity but softens the impct. Most modern series of corrective opertions for tetrlogy of Fllot hve opertive mortlities well below 10% nd good long-term results. I would hope Dr. Gustfson would continue to collect dt nd report his results gin in severl yers. I note tht 18 of the 40 ptients were operted on using circultory rrest s the perfusion technique. Our group would gree with this choice. It ppers tht myocrdil protection is better when one uses circultory rrest rther thn conventionl crdiopulmonry bypss, especilly in cynotic children. We hve mesured myocrdil ATP levels in 10 ptients operted on in the first yer of life using circultory rrest nd compred them to nother 10 ptients operted on using crdiopulmonry bypss. ATP levels were better preserved in the circultory rrest group thn in those with stndrd crdiopulmonry bypss. We believe our findings my be relted to the fct tht myocrdil rewrming is much less problem with circultory rrest, especilly in cynotic lesions like tetrlogy of Fllot, thn in conventionl crdiopulmonry bypss. I would be interested in the uthors views on the subject of myocrdil protection relted to perfusion technique in this series. Finlly, the uthors stte in both the bstrct nd the mnuscript tht the results in this series justify the routine ppliction of primry correction of tetrlogy regrdless of ge. In my opinion, the fct tht only 10 ptients in this series were below 1 yer of ge nd the exct number below 6 months of ge ws not specified does not justify this ssertion. In severl lrger series of tetrlogy repirs, including our own, younger ge t primry repir, especilly below 6 months, cn be identified s n incrementl risk fctor for opertive mortlity. In neontes it ppers tht crdiopulmonry bypss in the

7 241 Gustfson et l: Erly Repir of Tetrlogy of Fllot presence of immture orgn systems my be n dditionl risk fctor. When one dds this fctor to the known fct tht infnts who present with symptomtic tetrlogy tend to hve more diffuse hypoplsi of the right ventriculr outflow trct nd will thus require more extensive reconstruction, opertions in the first 3 to 6 months of life hve to be considered in different light. If no other therpy were vilble, this ggressive pproch would be justified. However, the two-stge ttck on the problem with preliminry shunting in infncy nd elective repir before 2 yers of ge is very resonble pln of therpy. We hve performed 43 Bllock-Tussig shunts in infnts nd hve hd 1 non-crdic deth since 1975 in our institution. Secondry repir hs been performed in the vst mjority of these ptients with combined mortlity of 4.3%, similr to the mortlity of 3% in lrger group of 200 ptients with primry repir. We feel tht this spectrum of tetrlogy is quite vried nd does not permit blnket surgicl pproch, but insted creful evlution of ech ptient with the surgicl therpy tilored to the extent of the pthology. Agin, our congrtultions to the uthors nd our pprecition to the Society for the privilege of the floor. DR. GUSTAFSON: Certinly we relize tht the series is not lrge enough to drw blnket conclusions, s Dr. Hmmon hs mentioned. We feel, however, tht the results tht we hve gotten with erly correction re s good s one cn get with n initil Bllock-Tussig shunt. Certinly 10 infnts is not lrge enough series to vlidte tht conclusion. We felt constrined by the fct tht we hd submitted the bstrct nd so we did not updte our results. However, 7 dditionl ptients under the ge of 1 yer hve undergone correction since the time of the bstrct nd still we hve no deths in the series. We certinly gree with Dr. Hmmon tht hypothermic rrest is the wy to go. If possible, we would prefer to operte on ll ptients with tetrlogy of Fllot within the first yer of life. Our men ge of opertion, which ws 2 yers of ge in the bstrct, is now 16 months of ge for ll elective opertions. Once gin I would like to thnk the Society for the opportunity to present these dt. Notice from the Southern Thorcic Surgicl Assocition The thirty-fifth Annul Meeting of the Southern Thorcic Surgicl Assocition will be held t the Mrco Islnd Resort, Mrco Islnd, FL, November 10-12, There will be $125 registrtion fee for nonmember physicins except for guest spekers, uthors nd couthors on the progrm, nd residents. There will be $50 registrtion fee for ttendees of the Postgrdute Course on Sturdy, November 12, The Postgrdute Course of the Southern Thorcic Surgicl Assocition hs been expnded to full dy nd will provide in-depth coverge of thorcic surgicl topics selected primrily s mens to enhnce nd broden the knowledge of prcticing thorcic nd crdic surgeons. Members wishing to prticipte in the Scientific Progrm should submit n originl bstrct nd one copy by My 15, 1988, to Robert M. Sde, M.D., Progrm Chirmn, Southern Thorcic Surgicl Assocition, 111 Est Wcker Dr, Chicgo, IL Abstrcts must be submitted on the Southern Thorcic Surgicl Assocition bstrct submission form. These forms my be obtined from the Assocition s office or in this issue of The Annls of Thorcic Surgery. All slides used during the presenttion must be 35 mm. Mnuscripts of ccepted ppers must be submitted to The Annls of Thorcic Surgery prior to the 1988 meeting or to the Secretry-Tresurer t the opening of the Scientific Session. Applictions for membershp should be completed by July 1, 1988, nd forwrded to the Southern Thorcic Surgicl Assocition, 111 Est Wcker Dr, Chicgo, IL Gordon F. Murry, M.D. Secret y-tresurer Southern Thorcic Surgicl Assocition Bsic Science Center West Virgini University Medicl Center Morgntown, WV 26506