MONDAY AFTERNOON, May 11, 1981

2:00 P.M. Scientific Session - International Ballroom

7. Anatomic Correction of Transposition of the Great Arteries

ADIB D. JATENE*, VALMIR F. FONTES*,

LUIZ CARLOS BENTO DE SOUZA *, PAULO P. PAULISTA *,

CAMILO ABDULMASSIH NETO* and

J. EDUARDO M. R. SOUZA*, Sao Paulo, Brazil

Sponsored by: E. J. Zerbini, Sao Paulo, Brazil

Twenty-seven patients had anatomic correction for transposition of the great arteries since 1975, when we first reported this technique. Twelve of them were under 6 months, and 19 under 1 year of age. In all but one the pressure in the left ventricle was systemic. The ventricular septal defect was present in 24 cases. Persistent ductus was present in 6 cases, in 4 of them associated to the ventricular septal defect. Only 1 patient had absence of PDA and VSD. The hospital mortality for the entire group was 59.2%. In 10 patients the indication for the operation was considered inadequate; in 9 due to an exceedingly high pulmonary vascular resistance, and in 1 to a low left ventricular pressure. All of them died. The 17 remaining patients, all with VSD, had left ventricular pressure at systemic level. Ten of these patients without any significant pulmonary outflow tract stenosis have low pulmonary vascular resistance. Four of these patients died (40.0%) in relation to the operation. In 3 of them the fatality could possibly have been avoided. The remaining 7 patients had pulmonary outflow tract obstruction; sub-valvular stenosis in 3 cases, and previous pulmonary banding in 4. The hospital mortality was 28.5% (2 patients). Eleven patients survived the operation. One of them presented late pulmonary stenosis and died at the re-operation, 5 years after the initial correction. One patient has partial recurrence of the VSD and is under evaluation for a possible re-operation to repair this residual defect. Follow-up studies in the remaining 9 patients from 2 to 51 months revealed an evolution considered very satisfactory. Five successful cases in the last 6 consecutive operations suggest the usefulness of this technique in proper selected cases.

*By invitation

8. Primary Definitive Repair of Interrupted Aortic Arch, VSD and PDA - Early and Late Results

ANTHONY L. MOULTON* and

FREDERICK O. BOWMAN, JR., Baltimore, Maryland

and New York, New York

Type B Interrupted aortic arch (IAA) with ventricular septal defect (VSD) and patent ductus arteriosus (PDA) usually presents with severe congestive failure in the first few weeks of life. It remains a highly lethal lesion and controversy exists about the optimal management of these patients. Most reported "repairs" have involved the use of prosthetic tubes or sacrifice of some of the arch vessels, often with simultaneous artery banding. This reports our experience with primary definitive repair of the aortic arch and closure of the VSD.

Since March 1974, seven patients, aged 7 days to 5 months, with Type B IAA + VSD + PDA were treated at the Columbis-Presbyterian Medical Center. Five of these patients underwent total correction utilizing deep hypothermia and circulatory arrest. Repair involved resection of all ductal tissue, primary anastomosis of the aortic arch, closure of the foramen ovale and patch closure of the VSD. All arch vessels were preserved and no prosthetic material was used to reconstruct the aortic arch.

One patient developed a coagulopathy and died 48 hours postoperatively. All others (80%) survived to hospital discharge. The patient repaired at 5 months of age had undergone pulmonary artery banding at another institution 3 months earlier; he died 8 months after correction from recurrent respiratory infections. Three patients are alive and well two to six years after repair. Two have undergone repeat cardiac catherization which demonstrated good growth of the anastomosis and no residual gradient. Primary definitive correction of Type B IAA + VSD + PDA provides distinct advantages over palliative or other surgical procedures with excellent long-term results.

*By invitation

9. Experience with Surgery for Hypoplastic Left Heart Syndrome

WILLIAM I. NORWOOD*, PETER LANG*,

ALDO R. CASTANEDA and DAVID N. CAMPBELL*,

Boston, Massachusetts

Aortic atresia (hypoplastic left heart syndrome: HLHS) is a common, uniformly lethal form of congenital cardiac anomaly with no established surgical management. From 1/79 to 11/80, 11 infants (4 female, 7 male) ranging in age from 1 day to 6 months (median 5 days) entered a study of staged repair of HLHS. All had aortic atresia (AA) except 1 with severe aortic and mitral stenosis and a markedly hypoplastic left ventricle (LV). Nine had associated mitral atresia (6) or mitral stenosis (3) with miniscule or no LV. Two had an associated ventricular septal defect (VSD) with only mild LV hypoplasia. One with AA and a VSD had associated Type C interrupted aortic arch (1AA) as well. The principles of the first stage in all were to establish a permanent communication from right ventricle (RV) to systemic circulation, normalize pulmonary flow and pressure, and insure unrestricted pulmonary venous inflow. The first 3 had placement of a valved conduit from RV to thoracic aorta (Ao), banding of main pulmonary (PA), ligation of PDA, and creation of ASD. One of these 3 subsequently had end-to-side anastomosis of proximal PA to augmented Ao and arch along with a systemic to PA central shunt. The last 7 had the latter reconstruction as stage one. There are 4 survivors. Early mortality was 48% (5/11) from hemorrhage (1), hypoxemia (2), and iatrogenic myocardiac ischemia (2). Late mortality was 33% (2/6) from aspiration (1) and throm-botic stenosis of valved RV to Ao conduit (1)6 and 4 months postopera-tively. Late (13 months) postop cath of the oldest survivor revealed a growing reconstructed Ao, no RV to thoracic Ao pressure gradient, 12 mm Hg mean PA pressure, 75% Ao O²saturation and he is awaiting last stage modified Fontan repair. One with AA, VDS, and 1AA is clinically well and thriving 11 months following complete repair by apical-aortic conduit, graft interposition between ascending and thoracic Ao and VSD closure initiated at age 4 days.

Much has been learned and much remains to be learned but a surgical solution for HLHS appears possible.

*By invitation

10. Long-Term Results of Repair of Incomplete Persistent Atrioventricular Canal

DANIEL M. GOLDFADEN*, MICHAEL JONES* and

ANDREW G. MORROW, Bethesda, Maryland

We evaluated the late results following the repair of otherwise uncomplicated incomplete persistent atrioventricular canal in 39 consecutive patients who underwent operation at our institution prior to 1976. Average follow-up duration was 13 years (range 5-24 years). Median age at operation was 12 years (range 1 to 68 years). In all patients the repair included patch closure of the atrial septal defect and direct suture repair of the cleft anterior mitral valve leaflet. Thirty-five patients (90%) had postoperative cardiac catheterizations at an average of 11 months after operation. Five patients (14%) had mild to moderate mitral regurgitation demonstrated by elevated mean pulmonary arterial wedge or left atrial pressures (12 - 15 mm Hg), with abnormally elevated v waves. Two patients (6%) had severe residual mitral regurgitation, with mean pulmonary arterial wedge pressures greater than 20 mm Hg. Clinically significant serious arrhythmias, including complete heart block (one early and two late), sudden death, nodal rhythm, and the development of chronic atrial fibrillation occurred in 7 patients (18%). Two patients required reoperation for mitral regurgitation at one and ten years after the initial operation. Seven patients currently are symptomatic because of mitral regurgitation. Of these, five had mitral regurgitation demonstrated at early postoperative catheterization; the other two developed it late. Twenty-six patients are asymptomatic at most recent evaluation. Actuarial survival is 88 ± 6% at 13 years after operation; survival free without reoperation is 82 ± 6%. However, survival and free of any late complications, including late death, reoperation, arrhythmia, or symptomatic mitral regurgitation is 52 ± 10% at 13 years.

INTERMISSION - VISIT EXHIBITS

*By invitation

11. Continuing Improvements in Valvular Bioprosthesis

ALAIN F. CARPENTIER*, CHARLES DUBOST,

JEAN-NOEL FABIANI*, ALAIN DELOCHE*,

SYLVAIN CHAUVAUD* and JOHNRELLAND*, Paris, France

Since the introduction of Glutaraldehyde in the preservation of valvular bioprosthesis in 1968, extensive research has been carried out to minimize three persistent drawbacks: transvalvular gradients, fatigue lesions and calcifications.

Since transvalvular gradients result from the impedance caused by the stent and the aortic remnant supporting the cusps, valve design has been recently modified so as to implant the valve in the supra-annular position. Only the cusps of the supra-annular valve (SAV) remain exposed to the blood column. In vitro tests comparing the SAV with disc valves have shown the gradients to be comparable (SAV 8.5 mmHg, Bjork 14.4 mmHg, St. Jude 8 mmHg at 15 1/minute). Other changes in the stent design include optimized flexibility of the stent so as to be similar to that of a normal aortic root and reduction of strut height of the mitral model so as to minimize protrusion within the ventricular cavity.

Many reports have shown that most of the commercially available bio-prostheses display various histological lesions even prior to their implantation. These lesions are different in severity from one commercial laboratory to another and from one valve to another in the same laboratory. Fatigue testing using pulse duplicators has proven that the variability in histological lesions was well correlated with durability of the valve which averaged 450 million cycles with a wide range from 10 to more than 600 million cycles.

Extensive review of the entire process of valve preparation revealed that these variations in histological structure and durability resulted from inadequate preservation of the valve during the shipping process and large variations of the intervals between harvesting and Glutaraldehyde treatment (from 12 to 90 hours). A technique using a balanced salt solution which will be described in detail was therefore developed to improve shipping conditions and fixation was accomplished imperatively within the first 48 hours. Electron microscopic studies have shown that histological lesions have been eliminated. Fatigue tests studies have shown an improved average durability up to 650 million cycles with limited variations.

As shown both experimentally and clinically, calcifications result from various factors: turbulence, histological lesions prior to implantation, calcium metabolism, age of the patient, diet, etc. Reduction of turbulences by the supra-annular concept and improved preservation of the valve should hopefully minimize the incidence of calcification. The feasibility and possible benefit of low calcium diet is currently under investigation. Thirty-four SAV have been implanted clinically in the past 6 months with no mortality and no complication thus far. Post-operative hemodynamic data are available in 10 patients.

*By invitation

12. Three Years Experience with the St. Jude Medical Valve Prostheses: Clinical and Hemodynamic Results

DEMETRE M. NICOLOFF, ROBERT W. EMERY*,

KIT V. AROM, WILLIAM F. NORTHRUP, III*,

CHARLES F. JORGENSEN*, YANG WANG* and

WILLIAM G. LINDSA Y*, Minneapolis, Minnesota

During a three year period beginning October 1977, 222 St. Jude Medical (SJM) mechanical heart valve prostheses were implanted in 210 patients with ages ranging from 18 months to 82 years, (116 aortic, 104 mitral and two tricuspid). The operative mortality (OM) for the aortic valve replacement (AYR) alone was 6.4% (78 cases) and 7.8% when valve surgery was combined with coronary artery bypass, mitral valve replacement (MVR) and ascending aorta replacement (38 cases). The OM was 5.3% for MVR (75 cases) and 8.7% when combined with other procedures (29 cases). None of these early deaths were related to valve failure. There were also NO significant early post-operative complications. Prior to discharge, the Hgb and platelet counts were compared to those of pre-operative valves; LDH was mildly elevated (319 ± 10 in AYR, 350 ± 22 in MVR).

In the mitral position, 926 patient-months follow-up revealed two hemolyses, two paravalvular leaks, two infections, and one embolus. There was NO valve malfunction or thrombosis. There was one death (after five months) from a coronary embolus. In the aortic position, 1153 patient-months follow-up revealed NO LATE COMPLICATIONS. There were two deaths, one at six months and one at eight months (1-CVA, 1-other cause).

At this time, 33 (22 AVR, 11 MVR) elective cardiac re-catheterizations have been performed (5 ± .3 months) showing the cardiac output (CO) to be improved from 5.1 ± .3 to 6.0 ± .3 L/min. (p<.001) in AVR and 3.6 ± .3 to 4.1 ± .3 L/min. (p<0.01) in MVR. PCWP decreased 14 ± 2 to 8 ± 1 mmHg (p<.005) in AVR and 22 ± 2 to 16 ± 2 mmHg (p<.01) in MVR. Transvalvular aortic peak systolic gradient (PSG) at rest varied from 0 to 12.0 mmHg (13/22 had 0 gradient) and 0 to 6.0 mmHg (8/11 had 0 gradient) in the mitral position. Effective valve area is not calculated since 21 patients had no transvalvular gradient. Following exercise, the PSG increased from 1 ± 1 to 4 ± 1(11 AVR) and 1 ± 1 to 5 ± 2 mmHG (5 MVR) and the CO increased to 10 ± 1.0 L/min. (11 AVR) and 7 ± 1.0 L/min. (5 AVR).

CONCLUSION: Three year follow-up of the SJM cardiac valve prostheses showed low transvalvular gradients, minimal hemolysis, and no thrombosis.

*By invitation

13. Tricuspid Valvulectomy Without Prosthetic Replacement: Ten Years of Clinical Expeience

AGUSTIN ARBULU and INGIDA ASFAW, Detroit, Michigan

The purpose of this paper is to report 54 patients that underwent tricuspid valvulectomy (TV) without replacement for bacterial endocarditis. Twenty-two cases were operated upon by the authors and 32 by other surgeons in the United States and Europe for a period ranging 1 to 10 years. Forty-eight patients were addicted to intravenous narcotics and six were not. In 34, the infection was due to gram negative bacteria. In 15, it was due to gram positive bacteria. In three patients the organism was a fungus; in one the infection followed trauma and in the last patient followed cancer invasion of the tricuspid leaflets. In 33 patients the diagnosis of right-sided endocarditis was made by the clinical picture alone. In three cases the cardiac catheterization was diagnostic. In 14, the combination of the clinical picture and cardiac catheterization, and in four echocardiogram was necessary to establish the diagnosis. In all patients intensive intravenous antibiotic treatment given for an average period of seven weeks, failed to cure the infection prior to the operation.

In 50 patients (93%) the endocarditis was cured after the TV. Subsequent to this operation 13 patients required a tricuspid prosthesis for various reasons. Of the 37 patients that did not require a tricuspid prosthesis 27 (73%) are in good condition and three in fair condition. In this group, seven patients died; two accidental, and five of a second endocarditis. None of these deaths were related to the TV. Of the 13 patients that required a prosthesis, eight (62%) are in good condition, one is in fair condition and four have died with infected prostheses.

WE CONCLUDE that TV is a curative operation for intactable right-sided endocarditis in more than 90% of the patients. The insertion of a prosthesis in these patients does not improve survival and quality of life. No patient had died as a consequence of the TV. In contrast, after a period of bacteriological cure, four patients (30%) died due to an infected tricuspid prosthetic valve.

*By invitation

14. The Hospital Mortality of Re-Replacement of the Aortic Valve: Incremental Risk Factors

FRED E. WIDEMAN*, EUGENE H. BLACKSTONE*,

JOHN W. KIRKLIN, ROBERT B. KARP, and

NICHOLAS T. KOUCHOUKOS, Birmingham, Alabama

Two hundred patients had re-replacement of the aortic valve as an isolated procedure or combined with coronary artery bypass grafting or resection of ascending aortic aneurysm between January 1, 1975 and July 1, 1979. 10 patients (5%, CL 3.4%-7.1%) died in hospital, compared with 24 deaths (2.8%, CL 2.3%-3.6%) among 842 patients undergoing isolated or combined primary replacement (p = 0.12). 6 of the 10 patients died with acute cardiac failure, 2 with hemorrhage (both from accidents at sternotomy), and 2 with neurologic deficits (each with innominate vein transection and then ligation). 17 (3.9%, CL 2.4%-6.0%) of 181 patients died in hospital after the first re-replacement (p for difference from initial replacement = 0.5), but 3 (15%, CL 7%-29%) of 19 died after the second or third re-replacement (p = 0.001). By simple contingency table analysis, NYHA Class IV increased the risk of hospital death after re-replacement (p = 0.002), as did active endocarditis of the previously implanted valve, and lack of use of cardioplegia (p = 0.03). Logistic multi-variate analysis showed high NYHA Functional Class III or IV (p = 0.02), absence of cardioplegia (p = 0.09), and long ischemic time (p = 0.03) to be incremental risk factors. These findings, and the suspected increased proportion of paravalvar leaks after multiple re-replacements, and perhaps of infection, indicate that: 1) patients with infected aortic valve bio-prosthesis or prostheses, or with paravalvar leaks, should have reoperation before acute or severe hemodynamic deterioration. 2) The sternotomy for reoperations should be made with special attention to avoiding damage to underlying structures. 3) Cardioplegia should be used, but even with this cardiac ischemic time should be as short as possible. 4) The first re-replacement should be with a well-proven prosthetic valve.

*By invitation

15. Valve Replacement in Children: A 15 Year Perspective

TIMOTHY J. GARDNER*, J. MICHEL ROLAND* and

JAMES S. DONAHOO, Baltimore, Maryland

Since 1965, valve replacement has been performed on 64 children between the ages of two months and 19 years. Two of the patients underwent a second successful valve replacement eight and ten years following their initial surgery, while 19 additional patients had multiple cardiac surgical procedures performed. Isolated aortic valve replacement was accomplished in 28 patients with one early and two late deaths. Twenty-three patients had isolated mitral valve replacement with two hospital deaths and with three late deaths, also valve-related. Tricuspid valve replacement was performed in nine patients, two of whom died early postoperatively. Double valve replacement was carried out on four children without early or late mortality. Overall hospital mortality was 7.8%.

Of 19 patients with heterograft valves, all implanted since 1975, one developed valve degeneration in the mitral position, three years postoperatively. There have been no other tissue valve failures. Three children with mechanical valves developed severe tissue overgrowth two to ten years postoperatively. One fatal valve thrombosis occurred in the tricuspid position and an additional patient with an aortic Bjork-Shiley valve sustained a massive stroke. There has been one major anticoagulant complication, massive hematuria, which necessitated nephrectomy in a patient with a Starr-Edwards prosthesis. Four children, including three infants, have recently had successful mitral valve replacement with St. Jude prostheses. These four children have undergone postoperative catheteriza-tions which confirm excellent prosthetic valve function.

The late survival noted in the entire group and the infrequency of either thromboembolic or anticoagulant-related morbidity is enouraging. In addition, the current availability of the St. Jude prosthesis which has excellent hemodynamic characteristics in small annulus sizes allows for greater flexibility in valve substitution for children.

*By invitation