2:00 p.m. Scientific Session - Grand Ballroom

41. The Results of Management of Simple Transposition in the Current Era

ALDO R. CASTANEDA, GEORGE A. TRUSLER,

MILTON H. PAUL*, EUGENE H. BLACKSTONE,

JOHN W. KIRKLIN and THE CONGENITAL HEART

SURGEONS SOCIETY

Multi-Institutional

Between January 1, 1985 and June 1, 1986, 245 neonates less than than 2 weeks old with transposition (TGA) have been entered into an ongoing 20 institution prospective study. 187 had simple TGA, and 154 (82%) of these were less than 48 hours old on entry. Percent survival 1,6, and 12 months after entry was 91%, 86%, and 81% respectively; there was an initially high but rapidly declining early phase of hazard function for death, giving way to a constant phase about 6 weeks after entry. 78 patients (16 deaths, 21%) were in a management program which included arterial switching, and 104 (9 deaths, 9%) in a program which included atrial switching.

Risk factors for death among the 182 patients were low birthweight (but not weight at operation), earlier date of entry into the study, and an arterial switch repair in an institution without a formal protocol of one type of operation or the other. Otherwise, neither arterial nor atrial switch protocol nor a protocol of Mustard vs. Senning type of atrial switching, nor a small patient volume institution, were risk factors for death in this experience to date.

An inference is that, as yet, neither of the formal treatment protocols (arterial vs. atrial switching) can be considered more advantageous as regards survival, but lack of a defined protocol is disadvantageous. Earlier date of entry into the study was observed to be a risk factor in the case of patients in a program of arterial switching because of recently decreasing risks of the arterial switch repair (0 deaths among 28 neonates undergoing arterial switching in protocol institutions (1/1/1986-6/1/1986); in the case of programs of atrial switching, it was because of fewer deaths prerepair. The improvement recently was particularly evident in small birthweight neonates. For those with a birthweight of 2.0 kg., predicted 12 month survival in either an arterial or atrial switch management program was 57% with entry January 1, 1985 and 86% with entry January 1, 1986; for those with a birthweight of 2.7 kg., it was 76% and 90% respectively.

*By Invitation

42. Long-Term Outlook After Atrial Correction for Transposition of Great Arteries: Cautious Optimism

MARKO I. TURINA *, ROBERT SIEBENMANN*,

PETER NUSSBAUMER* and AKE SENNING

Zurich, Switzerland

Late results were reviewed in 220 survivors after atrial correction of TGA, operated between 1964 and 1985. Senning's procedure and its various modifications have been employed; all patients which survived 30 days after correction were included in this analysis. Average follow-up for the whole group was 9.2 years; 113 pts were observed for 10, 26 pts for 15 and 8 pts for 20 years. Actuarial survival for the whole group was 89% at 10, 87% at 15 and 82% at 20y; it was higher in simple than in complicated TGA (92% vs. 84% at 10y). Sudden deaths (8 pts) and late heart failure (6 pts) were principal death cause, predominantly in complicated TGA group (10/14 deaths). Late survival was higher in the later part of the study, with 96% of pts corrected after 1977 surviving 8y, as opposed to 86% of pts operated earlier. Late reoperation was necessary in 21 pts (9.5%), with 12 reoperations occurring within 2y after correction. Cumulative incidence of reoperations reached 10.9% after 10y. Reoperations were more common in complicated than in simple TGAs (7.8% vs. 3.1% at 10y). Late dysrhythmias can occur after atrial correction, and cumulative incidence of pacemaker implantations was 9.8% at 10y. Most of the survivors belong functionally to an asymptomatic or oligosymptomatic group (83% of simple and 78% of complicated TGAs). Tricuspid valve incompetence was encountered only in 3 pts, with 2 valve reconstructions being possible. In summary, long-term outlook for survivors of atrial correction for TGA remains encouraging, although complicated TGA does seem to encounter more late problems. Atrial correction is still warranted in simple TGA, but cardiological surveillance is necessary.

*By Invitation

43. Early and Late Results of Modified Fontan Operation

GORDON K. DANIELSON, FRANCISCO J. PUGA,

HARTZELL V. SCHAFF*, RICHARD A. HUMES*

and DOUGLAS D. MAIR*

Rochester, Minnesota

From October 1973 to January 1986, 421 patients have undergone the modified Fontan operation. Diagnoses include tricuspid atresia (n = 145), double inlet ventricle (n = 131), and other complex anomalies including mitral valve atresia, pulmonary atresia with intact ventricular septum, single AV valve with single ventricle (two-chambered heart), single ventricular anomalies with hypoplastic or straddling AV valves, and polysplenia/asplenia syndromes (n = 145). Ages ranged from 8 mos to 42 yrs (mean = 11 yrs). One or more (maximum of eight) of Fontan and Choussat's original criteria for operability were not satisfied in 75% of the tricuspid atresia patients and 65% of the double inlet ventricle patients. There were a total of 67 hospital deaths (17%). Mortality was correlated with elevation of mean pulmonary artery pressure, pulmonary arteriolar resistance, and ventricular end-diastolic pressure; presence of AV valve insufficiency; and decreased ventricular function. In the last five years, total hospital mortality has decreased to 13%. Improved mortality was seen in all anatomic subsets: tricuspid atresia 10% overall, 5.3% last five years; double inlet ventricle 15% overall, 11.4% last five years; other complex anomalies 24% overall, 19% last five years.

Follow-up data were examined on 211 patients 3 mos to 11 yrs (mean = 3.1 yrs) after operation. Of numerous variables examined, late mortality (9.4%) correlated best with presence of ventricular dysfunction. Ninety-two percent of patients were in NYHA Class I or II, 95% were able to work or attend school, and 90% claimed to be improved following operation. Forty-three percent of patients were on no medications. Eighteen percent had some degree of intermittent or persistent edema.

Conclusions: 1) the modified Fontan operation can be performed successfully for a variety of functional single ventricle anomalies, 2) hospital mortality has decreased progressively with experience, 3) functional improvement at intermediate follow-up is good to excellent in most patients.

*By Invitation

44. Repair of Ebstein's Anomaly by Longitudinal Ventricular Plication and Tricuspid Valve Repositioning

ALAIN F. CARPENTIER, SYLVAIN CHAUVAUD*,

JOHN Y. M. RELLAND* and LOIC MACE*

Paris, France

Ebstein's anomaly is a rare and complex malformation of the tricuspid valve and the right ventricle. The tricuspid valve malformation involves the posterior and lateral leaflets which are displaced downwards and also the anterior leaflet which may be partially or totally adherent to the muscular wall. The right ventricular anomaly consists of a transverse rather than a longitudinal dilatation of the posterior wall above the displaced leaflets. The anatomical considerations led to the development of a reconstructive operation which comprises:

- A longitudinal plication (instead of the classical transverse plication) of the dilated portion of the right ventricle.

- A separation of the anterior and posterior leaflets from their annular attachment so as to facilitate leaflet mobilization and subsequent repositioning at the normal level.

- An annuloplasty using a Carpentier ring to remodel the orifice.

This technique has enlarged the indications of valve repair in Ebstein's disease with an increased efficiency. In a series of 13 patients operated upon in the past 5 years. Twelve (92%) benefited from this operation and 1 patient with an associated atrioventricular canal required a valve replacement. The age of the patients ranged from 9 to 38 years (mean 25.1 years). All patients but 4 were in functional class III or IV prior to operation. Cardiothoracic ratio varied from 0.55 to 0.77 (mean 0.65). One patient has a previous Lillehei-Hardy operation and was repaired successfully. There were 2 hospital deaths (one in a patient with an associated complex malformation of the mitral valve) and no late deaths. Rhythm and conduction disturbances were improved postoperatively in half of the patients.

All patients but 1 are in class functional I or II. Echocardiography and Dpppler studies demonstrated good tricuspid valve function and a normal morphology of the right ventricle in all patients but 1.

*By Invitation

45. The Fate of the 12-MM Porcine Valve Right Ventricular-Pulmonic Artery Conduit: A 10-Year Experience

STEVEN W. BOYCE*, KEVIN TURLEY,

EDWARDS. YEE*, EDWARD D. VERRIER*

and PAUL A. EBERT

San Francisco, California

The 12-mm porcine valve conduit is the smallest conduit manufactured and is used in the youngest infants with the most diminutive pulmonary arterial systems. The natural history of these conduits is unknown.

Between 1975 and 1985, there were 49 hospital survivors following placement of a 12-mm valve right ventricular-pulmonic artery extra-cardiac conduit. Follow-up is available in 42 patients, aged 1 to 16 months (mean 3.5) and weighing 2.5 to 8.7 kg (mean 3.8). Twenty-eight patients (67%) have undergone subsequent conduit replacement, and 11 (26%) are alive and asymptomatic with a mean follow-up of 56 months. There were 3 late deaths. The interval between implantation and conduit change was 4.5 to 101 months (mean 44), allowing a weight gain of 5.8 to 32 kg (mean 14), prior to reoperation at age 15 to 117 months (mean 49). Despite elevated right ventricular pressures equalling systemic values, 37% of these patients were clinically asymptomatic. The gradient across the 12-mm valve conduit prior to explantation ranged from 30 to 173 torr (mean 83) with a near equal predilection for stenosis at the proximal anastomosis, valve, conduit, distal anastomosis, and main pulmonary artery. The intervening pulmonary artery growth determined the size of the replacement conduit, 14- to 25-mm (mean 16), and was the main factor influencing the results of reoperation.

This study demonstrates that the 12-mm porcine conduit affords palliation in this difficult subset of patients with the smallest pulmonary arterial systems. This palliation lasts longer than originally had been thought with stenosis occurring at multiple levels rather than the predominant problem of conduit intimal peel as previously suggested.

*By Invitation

46. Arterial Switch in Simple and Complex D-Transposition of the Great Arteries

FAROUK S. IDRISS, MICHEL N. ILBAWl,

SERAFIN Y. DELEON*, C. ELISE DUFFY*,

ALEXANDER J. MUSTER*, TERESA E. BERRY*

and MILTON H. PAUL *

Chicago, Illinois

Arterial switch (AS) was performed on 46 children with D-transposition of the great arteries (D-TGA), ages ranging from 2 days to 3 years. Twenty-two had intact ventricular septum (IVS) and primary repair in the first month of life (Group I) with death (mortality 9%). Group II included 12 infants with IVS who had AS after different preliminary procedures (11 pulmonary artery banding (PAB), 10 shunt, 1 atrial septectomy, 2 coarctation (COA) repair) with 1 death (mortality 8%). Group III included 12 patients with complex D-TGA with ventricular septal defect (VSD) (3 with repaired COA, 6 PAB, 5 Taussig-Bing, and 1 double VSD). Two patients had both coronary arteries from the same sinus and 1 had associated supra- and subvalvar left ventricular (LV) outflow stenosis that was resected. Five patients in this group had the VSD closed through the pulmonary artery (PA). There was one death (mortality 8%).Echocardiography and cardiac catheterization were used in pre and postoperative evaluation. Postoperative catheterization was performed on 14 patients after AS. In 1, a second VSD missed on the original study was found and the patient was reoperated successfully. In another patient from Group III with a previously repaired COA, a narrowing developed in the aortic arch after AS, presumably due to LeCompte maneuver. Echocardiographic studies at 0.93 ± 0.61 years of age available for 15 patients from Group I revealed normal LV function. The maximal LV outflow velocity was <1.6 ml/sec (normal) in all, with normal LV end-diastolic dimension predicted for weight at 101 ± 12%. Right ventricular (RV) velocity increase was trivial in 9 and mild in 1. There was no aortic valve insufficiency in 11, trivial in 2 and mild in 3. In the new PA valve, insufficiency was absent in 4, trivial in 7 and mild in 3. Six postoperative catheterizations in Group I at 1.1 ± 0.1 years of age revealed a mean RV pressure of 35 ± 5 torr. One patient has significant arrhythmias.

Several technical details and modifications led to decrease of mortality and morbidity, including modifications minimizing rotation of the coronary arteries, myocardial protection with one cardioplegia infusion instead of intermittent infusion, primary rather than staged repair on infants with IVS as close to birth as possible, limiting staged repair to infants less than 2.5 kg or when other significant abnormalities are present, and performing a scalloped aortic anastomosis and reconstruction of the PA with pantaloon patch to create an extra large anastomosis and prevent serious narrowing.

4:00 p.m. Adjourn

*By Invitation