Monday Afternoon, April 25, 1994

1:30 p.m. SCIENTIFIC SESSION - Grand Ballroom

Moderators: William A. Gay, Jr., M.D.

Valerie W. Rusch, M.D.

6. AN INSTITUTIONAL STUDY OF IMPROVING OUTCOMES AFTER THE ARTERIAL SWITCH OPERATION

Gil Wernovsky, M.D.*, John E. Mayer, Jr., M.D., Richard A. Jonas, M.D., John W. Kirklin, M.D., Eugene H. Blackstone, M.D., Frank L. Hanley, M.D. and Aldo R. Castaneda, M.D., Ph.D.

Boston, Massachusetts; Birmingham, Alabama and San Francisco, California

30 hospital deaths and 10 late deaths occurred among 470 patients undergoing an arterial switch operation in one institution between January 1983 and January 1992. The ventricular septum was essentially intact in 278, and a VSD (with double outlet ventricle in 28) was repaired in the other 192. A proper cross-sectional followup was performed in 1992. Multivariable analysis (hazard function domain) showed earlier date of operation to be a risk factor for death but only in the case of the senior surgeon (P<.0001 for interaction term <.0001); three new surgeons had survivals as high as the senior surgeon and no date of operation effect (Figure).

There were no clusters of deaths. Other multivariably determined patient risk factors for death were 1) retropulmonary course of left main or circumflex coronary artery, in various patterns, 2) dextrocardia, 3) older age at operation (Figure).

Procedural risk factors included 1) longer duration of circulatory arrest (linear relation, 3% deaths after 15 minutes, 14% after 90 minutes, P=.006), 2) concomitant aortic arch augmentation. The early improvement was related to overall improvements, not to neutralization of any one risk factor (although the duration of circulatory arrest was inversely related to date of operation, r=.4, P<.0001);improvement occurred along with reduction from 20% (1985) to 2.4% (1990, 1991) of patients in whom the arterial switch was aborted to an atrial switch. 61 patients underwent reintervention, usually (40 patients) for right ventricular outflow obstruction and within the first year after operation; the prevalence is less in recent years (P>=.0002). 98% of surviving patients are functionally normal at last followup.

*By invitation

7. LEFT VENTRICULAR FUNCTION EVALUATION UP TO FIVE YEARS AFTER DYNAMIC CARDIOMYOPLASTY

Luiz F.P. Moreira, M.D.*, Noedir A.G. Stolf, M.D.*, Edimar A. Bocchi, M.D.*, Paulo M.P. Fernandes, M.D.*, Fernando Bacal, M.D.* and Adib D. Jatene, M.D.

Sao Paulo, Brazil

Improvement of left ventricular function after dynamic cardiomyoplasty has been reported in patients with severe cardiomyopathies, but the long-term effects of this procedure remain unclear. In this study, 30 patients submitted to cardiomyoplasty for treatment of dilated cardiomyopathy were annually investigated with radionuclide scintigraphy, Doppler-echocardiography and right heart catheterization. They were in NYHA functional class III or IV before operation. There were no operative deaths and patients were followed-up from 3 to 66 months (mean, 24 months). Eleven patients died and one patient was submitted to heart transplantation during late follow up. Actuarial survival rates were 83.9% at 1 year, 66.2% at 2 years and 41% at 5 years of follow-up. Multivariate analysis of factors influencing outcome documented that long-term survival was significantly affected by preoperative functional class and pulmonary vascular resistance. Otherwise, NYHA functional class improved from 3.2 ± 0.4 to 1.6 ± 0.6 in the surviving patients (p<0.01). Furthermore, sequential laboratory investigation showed the long-term cardiomyoplasty influence on LV ejection fraction (LVEF), cardiac index (CI), LV stroke index (LVSI), pulmonary wedge pressure (PWP) and LV stroke work index (LVSWI): (* = p<0.05, in relation to preoperative data)

(Pts)	Preop.(25)	6 Mo.(25)	1 Yr.(19)	2Yr.(11)	3 Yr.(7)	4 Yr.(6)	5 Yr.(4)
LVEF (%)	20 ± 3	24 ± 6*	23 ± 6*	24 ± 6*	23 ± 3	21 ± 3	20 ± 4
CI (1/min/m²)	1.9 ± 0.3	2 ± 0.4	2 ± 0.4	2 ± 0.3	2.2 ± 0.3	2.2 ± 0.3	2.2 ± 0.2
LVSI (ml/m²)	21 ± 3	25 ± 7 *	24 ± 7*	25 ± 5 *	29 ± 4*	27 ± 6*	27 ± 5
PWP (mmHg)	24 ± 6	19 ± 6*	18 ± 6*	18 ± 7*	14 ± 3*	16 ± 6	19 ± 7
LVSWI (g.m/m²)	18 ± 5	26 ± 9*	25 ± 9*	25 ± 7*	33 ± 10*	29 ± 10*	27 ± 9

Thus, despite the LVEF tendency to decrease at late cardiomyoplasty follow-up, the long-term course of patients with dilated cardiomyopathy submitted to this procedure seems to be characterized by the maintenance of hemodynamic improvement. Otherwise, long-term survival after cardiomyoplasty is limited by the severity of patients' compromise before the operation.

*By invitation

8. INCIDENCE OF LOCAL RECURRENCE AND SECOND PRIMARY TUMORS IN RESECTED STAGE I LUNG CANCER

Nael Martini, M.D., Manjit S. Bains, M.D., Michael E. Burt, M.D., Ph.D., Maureen F. Zakowski, M.D.*, Patricia McCormack, M.D., Valerie W. Rusch, M.D. and Robert J. Ginsberg, M.D.

New York, New York

From 1973 to 1985, 598 patients underwent resection for stage I non-small cell lung cancer. There were 291 T1 lesions and 307 T2. The male to female ration was 1.9:1. The histology was squamous carcinoma in 233 and non-squamous carcinoma in 365. Lobectomy was performed in 511 patients (85%), pneumonectomy in 25 (4%), and wedge resection or segmentectomy in 62 (11%). A mediastinal lymph node dissection was carried out in 560 patients (94%) and no lymph node dissection in 38 (6%). There were 14 post-operative deaths (2.3%).

Ninety-nine percent of the patients were followed for a minimum of 5 years or until death with an overall median follow up of 86 months. The overall five and ten-year survivals (Kaplan-Meier) were 75% and 66%. Survival in TIN 0 tumors was (82%) at 5 years and 73% at 10 years compared to 68% at 5 years and 60% at 10 years for T2 tumors (p=0.009).

The overall incidence of recurrence was 27% (local or regional 26%. systemic 74%) and was not influenced by histology. There were 204 patients who developed second primary cancers (34%). Of these, 69 (34%) were second primary lung cancers.

Despite complete resection. 31 of 62 patients (50%) who had wedge resection or segmentectomy had recurrence. Five and 10 year survivals following wedge resection or segmentectomy were 59% and 35% significantly less than those undergoing lobectomy. The 5 and 10 year survivals in the 38 patients who had no lymph node dissection was also reduced to 59% and 32% respectively.

Apart from the favorable prognosis observed in this group of patients, three facts emerge as significant: 1) the importance of systematic lymph node dissection to ensure that these patients have truly stage I disease; 2) lesser resections (wedge/segment) result in high recurrence rates and reduced survival regardless of histology; and 3) the incidence of 2nd primary lung cancers is high in the long-term survivors.

2:30 p.m. BASIC SCIENCE LECTURE

Traffic Signals for Leukocyte Emigration from the Blood Stream

Timothy A. Springer, Ph.D., Boston, Massachusetts

3:15 p.m. INTERMISSION - VISIT EXHIBITS

*By invitation

4:00 p.m. SCIENTIFIC SESSION - Grand Ballroom

Moderators: Bruce A. Reitz, M.D.

L. Penfield Faber, M.D

9. COX-MAZE PROCEDURE FOR CHRONIC ATRIAL FIBRILLATION ASSOCIATED WITH MITRAL VALVE DISEASE

Yoshio Kosakai, M.D.*, Akira T. Kawaguchi, M.D.*, Fumitaka Isobe, M.D.*, Yoshikado Sasako, M.D.*, Yoshitsugu Kito, M.D.* and Yasunaru Kawashima, M.D.

Osaka, Japan

Atrial fibrillation (AF) often persists even after a successful mitral operation, undermining hemodynamics and necessitating anticoagulation. To treat AF associated with mitral valve disease, we combined Cox-Maze procedure in 62 patients with AF undergoing mitral valve repair (n=28) or replacement (n=34), including 16 reoperated cases. Associated procedures included aortic valve operation (22), tricuspid annuloplasty (32), atrial plication (10) and others (3). Duration of AF varied from 0.1 to 23 (average 8.3 ± 6.4) years, the f-wave voltage ranged from 0 to 0.45 (0.16 ± 0.09) mV, and cardiothoracic ratio varied from 46 to 85 (64 ± 9) %. We used separate atriotomies and cryoablation to preserve the sinus node artery. The superior vena cava was transected to improve exposure of the mitral valve. Aortic cross-clamp time varied from 92 to 212 (142 ± 25) minutes with bypass time ranging from 148 to 295 (226 ± 33) minutes. There were no early or late deaths in the follow-up ranging from 0.2 to 18.9 (7.8 ± 5.0) months. Although 3 patients required pacemaker implantation for sinus node dysfunction, a regular sinus or atrial rhythm was restored in 92% (46/50), 91% (31/34), and 100% (15/15) of patients 3, 6, and 12 months after surgery. The atrial a-wave was detected in 97% in the trans-tricuspid flow and 73% in the trans-mitral flow. Twenty-one patients are free from anti-arrhythmics, and all 11 patients with an atrial a-wave and a repaired valve are off anticoagulation 3 months after surgery. Since no preoperative variables are indicative of postoperative AF, Cox-Maze procedure is indicated to all patients with chronic AF undergoing mitral valve operation.

*By invitation

10. REPAIR OF THE AORTIC VALVE IN PATIENTS WITH AORTIC INSUFFICIENCY AND AORTIC ROOT ANEURYSM

Tirone E. David, M.D., Joanne Bos, R.N.* and Christopher M. Feindel, M.D.*

Toronto, Ontario, Canada

Composite replacement of the aortic valve (AV) and ascending aorta is the standard operation for pts with aortic insufficiency (AI) and aortic root aneurysm. However, the AV can be repaired in approximately one-third of these pts because the AV leaflets are normal or minimally diseased. The AI is due to annoloaortic ectasia and/or increase in the diameter of the sinotubular junction. When annuloaortic ectasia is marked, an aortic annuloplasty with reimplantation of the AV in a tubular Dacron graft is performed ("Reimplantation"). When annuloaortic ectasia is mild or absent, replacement of the sinuses of Valsalva and ascending aorta with a tailored tubular Dacron graft of diameter 10% smaller than the diameter of the aortic annulus is performed ("Remodeling"). In both types of procedures the coronary arteries have to be reimplanted into the Dacron graft.

From July 1989 to September 1993. 40 pts with AI and aortic root aneurysm had surgery with preservation of the AV. The pts clinical profile was the following.

	Reimplantation	Remodelling
Number of pts	19	21
Age (range) - years	44 (14 to 68)	65 (32 to 76)
Aortic root size (mm)	56 ± 5	61 ± 8
AI (grades 0 to 4)	2. 8 ± 0.8	2. 7 ± 0.9
Marfan syndrome	10	2
Acute type A dissection	8	1
Mitral regurgitation	3	0
Coronary artery disease	1	3

There was no operative death but one pt (the 2nd of the "reimplantation" series) had persistent AI and required composite replacement of the AV and ascending aorta. All pts have been followed from 1 to 52 months, mean of 19. A 14 year-old pt with Marfan syndrome required AVR two years later because of AI due to marked increase in the size of the leaflets. The remaining 38 pts have stable AV repair and have not had any cardiovascular complication. No one has more than mild AI as assessed by periodical Doppler echocardiographic studies.

These two types of AV repair have provided excellent clinical results in adult pts with AI and aortic root aneurysm, and the function of the AV has remained stable up to 52 months postoperatively.

*By invitation

11. LOBECTOMY: VATS VS THORACOTOMY. A RANDOMIZED STUDY

Thomas J. Kirby, M.D.*, Michael Mack, M.D.*, Rodney Landreneau, M.D.* and Thomas W. Rice, M.D.

Cleveland, Ohio; Dallas, Texas and Pittsburgh, Pennsylvania

The exact rose of video-assisted thoracic surgery (VATS) remains to be clearly defined by randomized studies comparing VATS to accepted thoracic surgical techniques and approaches. VATS lobectomy was compared to open thoracotomy in 55 patients randomized to either a muscle sparing thoracotomy (MST) and lobectomy (30 patients) or a VATS lobectomy (25 patients). All patients were carefully staged preoperatively and intraoperatively and found to have stage I or II non-small cell lung carcinoma. Each patient underwent a complete and potentially curative anatomic lobectomy using accepted thoracic surgical and oncologic principles. The two groups were compared using operating room time, intraoperative and postoperative complications, length of chest tube drainage, hospital stay and number of days of parenteral narcotics. The results are shown below.

	Age	Op Time (min)	CT (days)	LOS (days)	ParNar
MST	61.4	175 ± 85	5.1 ± 2.8	7.7 ± 5.6	3.8 ± 2.1
VATS	58.7	141 ± 70	4.4 ± 3.5	6.3 ± 3.4	2.6 ± 1.5

(Op Time-operating room time, CT-length of chest tube drainage, LOS= length of hospital stay, ParNar-Days of parenteral narcotics)

There was no significant difference between the two groups in operating room time, length of chest tube drainage, hospital stay or length of parenteral narcotic use. No significant intraoperative complications occurred in the VATS group requiring emergent conversion to a thoracotomy or intraoperative blood transfusion. Four VATS lobectomies were converted to a MST for technical reasons.

We conclude that VATS lobectomy does not offer significant advantages over a muscle sparing thoracotomy while in our opinion exposing the patient to the as yet undefined risk of performing a major pulmonary resection in an essentially closed chest.

*By invitation

12. THIRTEEN YEAR EXPERIENCE WITH "HOMOVITAL" HOMOGRAFTS FOR AORTIC VALVE REPLACEMENT

Magdi H. Yacoub, F.R.C.S., Nasser R.H. Rasmi, M.D.*, Thoralf M. Sundt, M.D.*, Eileen Boyland,*, Asghar Khaghani, F.R.C.S.*, Rosemary C. Radley-Smith, F.R.C.P, F.A.C.C.* and Andrew G. Mitchell, F.R.C.P.*

Harefield, England

Between February 1980 and July 1993, 264 patients have undergone aortic valve replacement using homografts taken under sterile conditions from patients undergoing cardiac transplantation and preserved at 4°C in tissue culture medium (mean interval = 3.9 days). Patients ranged in age from 1.5 to 79 years (mean = 45.5, SD = 19.4). The underlying pathology was congenital in 100 (76 bicuspid valves), calcific in 50, rheumatic in 30, Marfan syndrome in 9, degenerative in 9 and malfunction of a previously replaced valve in 54. Twenty patients (7.6%) had bacterial endocarditis, 15 active of which 8 had underlying pathology. Freehand two suture line technique was used in 144 and aortic root replacement with reimplantation of the coronaries in 120. Associated procedures were performed in 94 patients. The operative mortality was 3.4% for the total group of patients (264) and 0.6% mortality in the isolated group (170). With a mean follow up period of 4.1 years (SD = 3.4), there was 4.5% late mortality for the total group. Actuarial survival at 5 and 10 years for the entire group was 92.8%, 90.2% and was 95.7%, 92.0% for those undergoing isolated valve replacement. Seven patients have required reoperation for valve failure (1.5 to 8.2 years postoperative), 5 due to bacterial endocarditis (3 recurrent and 2 de novo); 1 due to valve degeneration and 1 due to technical failure, with no mortalities. The probability of freedom from valve failure was 97.8% and 91.2% at 5 and 10 years in the entire group of patients. There have been no episodes of thromboembolism. Thus far, multivariant analysis did not identify any risk factor for late degeneration including ABO incompatibility (known in all patients) and HLA matching (known in 37). We conclude that homovital homograft valves provide good 10 year results without evidence of accelerated rejection.

*By invitation