1:30 p.m. PLENARY SCIENTIFIC SESSION

Ballroom, Hynes Convention Center

Moderators: David B. Skinner, M.D.

Tirone E. David, M.D.

7. TECHNIQUES AND RESULTS OF MINIMALLY INVASIVE MITRAL VALVE SURGERY IN 100 PATIENTS: A PARADIGM FOR THE FUTURE.

†Lishan Aklog, M.D.*, ‡David H. Adams, M.D.*, Gregory S. Couper, M.D.*, Samuel Sears, B.A.* and Lawrence H. Cohn, M.D.

Boston, Massachusetts

Discussant: Alain F. Carpentier, M.D., Paris, France

Minimally invasive techniques for mitral valve (MV) surgery have recently been developed to decrease surgical trauma and presumably reduce pain, morbidity, recovery time and cost. We used a minimally invasive right parasternal approach to determine if this technique could match the efficacy of standard MV surgery.

Between 7/96 and 10/97, 100 patients underwent minimally invasive MV repair or replacement. They represented 75% of all patients undergoing isolated, primary MV surgery during that period. The patients ranged in age from 30 to 83 years (mean 58.2), 56% were male and 44% female. The mean New York Heart Association functional class was 2.4. The indication for surgery was mitral regurgitation in 90% and mitral stenosis in 10% The most common pathologic findings were myxomatous degeneration (76%), rheumatic disease (12%) and endocarditis (6%).

A 5-8 centimeter, right parasternal incision was performed with resection of a portion of two costal cartilage. Bypass was instituted via the femoral vessels vein and superior vena cava in the majority of patients. However, most recently, we have used direct cannulation of the ascending aorta and a percutaneous femoral venous cannula to avoid groin incisions. The MV was approached transeptally through the right atrium in 85 patients and directly into the left atrium through the interatrial groove in 15.

Eighty-five patients underwent MV repair using standard reconstructive techniques and an annuloplasty ring in most patients (76 Cosgrove, 3 Carpentier-Edwards). Fifteen patients underwent MV replacement (11 St. Jude, 3 Hancock, 1 Carpentier-Edwards). All repairs and replacements were performed under direct vision with standard instruments. No patient required conversion to median sternotomy. The mean ischemic and bypass times were 100 and 151 minutes. Transesophageal echocardiography was used in every patients to evaluate the operation and monitor de-airing of the heart.

There were no operative deaths. All repairs were successful and there were no paravalvular leaks after valve replacement. Perioperative morbidity included new onset atrial fibrillation in 14 of 69 patients (20%), one reoperation for bleeding (1%), and one transient ischemic attack (1%). Blood transfusions were required in only 39% of patients. There were no wound infectious. The median hospital length of stay was 5 days (range 3-30) with nearly 40% of patients staying 4 days or less. Only 7% of patients required discharge to a rehabilitation facility. There were two late deaths (2%) and one stroke (1%). One patient required reoperation and valve replacement four months after MV repair. Post-operative pain and rate of return to normality" were improved when compared to patients having standard median sternotomy. By decreasing surgical trauma, minimally invasive MV surgery appears to have an associated decrease in morbidity over standard approaches. It may also result in increased patient comfort, a better cosmetic result, a faster rate of recovery, decreased length of stay and decreased post-hospital costs. Most importantly, these results show that minimally invasive MV surgery maintains the quality and efficacy of MV surgery.

†1998 International Traveling Fellowship

‡1992-94 AATS Alton Ochsner Research Scholar

*By invitation

8. FACTORS INFLUENCING TEN YEAR SURVIVAL IN RESECTED STAGES I-IHA NON-SMALL CELL LUNG CANCER.

Nael Martini, M.D., Valerie W. Rusch, M.D., Manjit S. Bains, M.D., Mark G. Kris, M.D.*, Robert J. Downey, M.D.* and Robert J. Ginsberg, M.D.

New York, New York

Discussant: Mark K. Ferguson, M.D., Chicago, Illinois

The objectives of this study were to determine: a) If patients continue to have recurrence of the primary tumor beyond five years; b) If there is a difference of survival beyond five years between N0 vs. N1, N0 vs. N2, and N1 vs. N2; c) Whether histology, age, or sex influence survival beyond five years. From 1973 to 1989, 686 patients were identified to be alive and well five years following complete resection of their lung cancers. The stage of their disease was IA in 263, IB in 261, IIA in 12, and IIIA in 82 patients. The histology was adenocarcinoma in 328, bronchiolar carcinoma in 84, squamous cell carcinoma in 244, and large cell carcinoma in 30. The extent of pulmonary resection was a lobectomy or bilobectomy in 579, pneumonectomy in 55, and wedge resection or segmentectomy in 52. A recurrence and a new lung primary were considered as failures to remain free of lung cancer. Of the 686 patients, 26 developed late recurrence and 36 new lung cancers. The median followup on all patients was 122 months. The overall survival at 10 years was 92.4%. Survival by nodal status at 10 years was 93% for N0 tumors, 95% for N1 tumors and 90% for N2. Survival by stage at 10 years was 93% for Stage I tumors and 91% for Stage II or III tumors.

There were 369 patients who lived 10 or more years from treatment of their initial lung cancer. In these patients, the incidence of late recurrence was 3 of 369 patients or less than 1%, where as the incidence of new lung cancers, although, reduced was more frequent than late recurrences (N = 15). The conclusions are: 1) Late recurrence is infrequent. 2) Second primary cancers exceed recurrence after five years. 3) Age, sex, histology do not influence 10 year survival. 4) Once the patients survive beyond five years there is no difference in survival between N0 vs. N1 or N2. They behave the same after 5 years.

9. MOBILISATION OF THE LEFT AND RIGHT FIBROUS TRIGONES FOR RELIEF OF SEVERE LEFT VENTRICULAR OUTFLOW OBSTRUCTION.

Magdi H. Yacoub, F.R.C.S., DSc. And Rosemary Radley-Smith, F.R.C.P.*

Harefield, England

Discussant: Frank L. Hanley, M.D., San Francisco, California

The management of fixed subaortic stenosis including tunnel obstruction continues to be controversial with a variable number of patients reported to undergo aortoventriculoplasty or insertion of an extracardiac conduit from the apex. We believe that the "ideal" operation should relieve the obstruction while maintaining the anatomic integrity of the left ventricular outflow tract (LVOT). To achieve this, a technique of radical excision of the obstructive tissue combined with mobilisation of the two fibrous trigones has been devised. This results in backwards displacement of the subaortic curtain and anterior leaflet of the mitral valve with further widening of the LVOT. This technique has been used since 1971 in 52 patients aged between 5 months - 56 (mean 15.5 ± 10.6) years. Additional lesions were present in 10; a ventricular septal defect (VSD) was present in 7 - proximal (between the valve and ring) in 3 and distal to the ring in 4. Coarctation of the aorta, persistant ductus arteriosus and congenital mitral stenosis were present in 3 patients respectively. Three patients had a bicuspid non-stenotic aortic valve, 6 patients a tricuspid stenotic valve, 1 patient endocarditis on a normal aortic valve and 1 aortic regurgitation due to damage from a previous operation. Five patients had had 7 previous operations on the outflow tract. In addition to resection of the obstruction, 3 patients had an aortic valvotomy, 2 a homograft replacement of the aortic valve, 7 patients patch closure of VSD and 1 an open mitral valvotomy. There were 2 (4%) early deaths (both early in the series), one in an 18 month old infant with a proximal VSD and one in a 7 year old with extremely poor LV function pre-operatively. With a followup of 1-25 years, no patient has required re-operation for recurrence of the subaortic obstruction. There has been 1 sudden late death 16 years after operation. All patients have echocardiographic evidence of good relief of the obstruction. It is concluded that mobilisation of the 2 trigones is a safe operation and gives lasting relief of the obstruction up to 25 years later.

2:30 p.m. BASIC SCIENCE LECTURE

The Future of Coronary Thrombosis Prophylaxis

and Management

Eric J. Topol, M.D., Cleveland, Ohio

3:15 p.m. INTERMISSION - VISIT EXHIBITS

*By invitation

4:00 p.m. PLENARY SCIENTIFIC SESSION

Ballroom, Hynes Convention Center

Moderators: David B. Skinner, M.D.

Tirone E. David, M.D.

10. MULTICENTER STUDY OF STENTLESS VALVES IN SMALL AORTIC ROOTS: DO STENTLESS VALVES RULE OUT REPLACEMENT DEVICE MISMATCH?

Ulrik Hvass, M.D.*, George Palatianos, M.D.*, Romeo Frassani, M.D.*, Cesare Puricelli, M.D.* and Mark O'Brien, M.D.

Paris, France; Athens, Greece; Udine, Italy; Brisbane, Australia

Discussant: Edward D. Verrier, M.D., Seattle, Washington

Four Cardiac Centers participating in an on-going clinical study of stentless porcine valves evaluated the results in patients with small aortic roots (19 and 21 mm annulus).

Out of a cohort of 567 patients, 171 patients (30,1%) had a small aortic root. Patient population comprises 163 cases with calcified aortic stenosis, 8 with valvular insufficiency. Sixty patients presented associated lesions mitral or coronary. Eighteen were redo operations. Mean age was 72 ± 4.2. Forty-seven of the small aortic root patients had an annulus of 19 mm and 124 had a 21 mm annulus. The body surface area (BSA) was respectively 1.55 ± 0.2 and 1.78 ± 0.45.

Hemodynamic evaluation of the stentless valve comprised serial measures of mean gradients, effective orifice area and left ventricular mass reduction. Complication rates for secondary events were evaluated over a 6 year period. Hospital mortality was 3.5% (6 patients: 2 were emergency redo operations, 1 sepsis, 1 mitral annular disruption, 1 bleeding and 1 myocardial infarction). Mean gradients after the first year were, in patients with 19 mm and 21 mm annulus respectively of 9 ± 2 mmHg and 6 ± 1.7 mmHg. EOA was 1.45 ± 0.3 and 1.72 ± 0.4 cm². Gradients and surfaces remain stable throughout the study period. Aortic regurgitation is zero to trace.

Left ventricular mass at discharge and at 1 year were respectively 296g ± 127 and 215g ± 102 for patients with a 19 mm annulus and 281g ± 75 and 236g ± 15 for patients with a 21 mm annulus.

Complication rate for secondary events is low: 2 embolic events in patients with atrial arrhythmias, 2 operated valvular endocarditis, no structural valve deterioration.

These results show that with stentless valves, patients with small aortic roots undergoing aortic valve replacement demonstrate excellent clinical and hemodynamic results, with low gradients, resulting in significant left ventricular mass reduction, ruling out any replacement device mismatch in this increasing group of patients.

*By invitation

11. PET-FDG IMAGING IS EFFICACIOUS IN EVALUATING PULMONARY MALIGNANCIES.

Geoffrey M. Graeber, M.D., Naresh Gupta, M.D.* and Gordon F. Murray, M.D.

Morgantown, West Virginia

Discussant: Robert J. Ginsberg, M.D., New York, New York

Positron emission tomography (PET), when used with the intravenously administered radiopharmaceutical F-18 Fluorodeoxyglucose (FDG), has the potential to help in the evaluation of patients with lung cancer since the radio-pharmaceutical is concentrated by metabolically active cells. We conducted a retrospective evaluation of PET-FDG in 96 patients assessed at our institution over the last two years for suspected primary pulmonary neoplasms. PET-FDG results were compared with the findings of CT scans on the same patients. All patients underwent surgical exploration and/or resection of their malignancies. All sites of potential malignancy underwent biopsy and/or excision of the masses with subsequent complete pathologic evaluation. Results: A total of 96 patients with suspected or proven primary pulmonary malignancies were evaluated. The male: female ratio was 68: 28. The age range was 43-80 years. Sixty-six patients had histologically confirmed malignancies: 35 adeno-carcinoma, 14 non-small cell, 10 squamous cell, 2 small cell, and 5 had various other malignancies. Thirty had benign masses histologically. PET-FDG had an accuracy of detecting malignancy in pulmonary lesions of 92% (Sensitivity 97%, specificity 89%). A total of 111 surgically sampled sites were from lymph nodes. PET-FDG was accurate in predicting the malignancy of nodes in 91% of instances whereas CT was correct in 64%. PET-FDG changed preoperative staging for "N" in 31/88 (35%) of patients (upstaged in 24 patients and downstaged in 7). Preoperative evaluation of lymph nodes using CT showed 17 enlarged (>1 cm) and consistent with malignant invasion; all 17 were predicted as true negatives by PET-FDG. Similarly six lymph nodes predicted by CT to be negative (<1.0 cm) were accurately detected by PET-FDG to have metastases. The sensitivity, specificity, and predictive accuracy of PET-FDG in detecting metastatic lymphadenopathy in mediastinal lymph nodes was 98%, 94% and 95% respectively. PET-FDG also changed "M" staging in 8 patients (6 with and 2 without metastases). Four patients were accurately shown to have osseous mets with negative or nonspecific bone scans. Three other patients with suspicious lesions on bone scan showed true negative PET-FDG findings. These initial results suggest that PET-FDG has high accuracy in identifying and staging patients with lung cancer. PET-FDG also appears to be more accurate in detecting metastatic mediastinal lymphadenopathy than CT scan.

*By invitation

12. INTERNATIONAL MULTI-CENTER APROTININ GRAFT PATENCY EXPERIENCE.

Jeffrey B. Rich, M.D.*, Edwin L. Alderman, M.D.*, Jerrold H. Levy, M.D.* and Hartzell Schaff, M.D. and the IMAGE Investigators.

Norfolk, Virginia; Stanford, California; Atlanta, Georgia and Rochester, Minnesota

Discussant: Stephen Westaby, M.D., Oxford, England

Background: Aprotinin, a serine proteinase inhibitor, reduces bleeding during coronary artery bypass graft (CABG) surgery. We examined the effects of aprotinin on graft patency, incidence of myocardial infarction (MI) and blood loss in patients undergoing primary CAGE surgery with cardiopulmonary bypass.

Methods: Patients (N = 870) from 13 international sites were randomized to receive intraoperative aprotinin (N = 436) or placebo (N = 434). Graft angiography was conducted a mean of 10.8 days postoperatively. Electrocardiograms, cardiac enzyme levels and blood loss and replacement were evaluated.

Results: In 796 assessable patients, aprotinin reduced the thoracic drainage volume by 43%(p<0.0001) and the requirement for allogeneic red blood cell administration by 49% (p<0.0001). Of 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients versus 10.9% of placebo-treated patients (p = 0.032). At U.S. sites, occlusions were seen in 9.4% of the aprotinin-treated patients and 9.5% of the placebo-treated patients (p = 0.720). At European sites, occlusions occurred in 23.0% and 12.4% of the aprotinin- and placebo-treated patients, respectively (p = 0.014). When adjusting for risk factors which were found to be associated with vein graft occlusion, the aprotinin versus placebo risk ratio was reduced from 1.7 to 1.5 (90% confidence interval, 0.6-1.8). Aprotinin did not affect the occurrence of definite MI (aprotinin: 2.9% versus placebo: 3.8%) or mortality (aprotinin: 1.4% versus placebo 1.6%). Conclusions: Given the costs and risks associated with transfusions, aprotinin remains an important and safe approach to surgical blood conservation.

*By invitation

13. VIDEO-ASSISTED SURGICAL MANAGEMENT OF ACHALASIA OF THE ESOPHAGUS.

Robert J. Wiechmann, M.D.*, §Mark K. Ferguson, M.D.*, Michael J. Mack, M.D.*, Ronald J. Aronoff, M.D.*, Steven Hazelrigg, M.D.*, Keith S. Naunheim, M.D.* and Rodney J. Landreneau, M.D.

Pittsburgh, Pennsylvania; Chicago, Illinois; Dallas, Texas; Springfield, Illinois; St. Louis, Missouri

Discussant: Antoon E.M.R. Lerut, M.D., Leuven, Belgium

Video-assisted surgical approaches to esophageal achalasia continue to be explored by many thoracic and general surgeons involved in the management of this esophageal motor disorder. We report our experience with thoracoscopic (VATS) and laparoscopic (LAP) esophagomyotomy to more clearly define the efficacy and safety of these approaches. Over a 70 month period, 54 patients with manometrically confirmed achalasia underwent VATS myotomy (n = 1 9) alone or LAP myotomy (n = 35) with partial fundoplication (D'or=15; Toupet = 20). Mean age was 47.9 years and average length of symptoms was 32 months. Prior management consisted of dilation in all patients, endoscopic botulinum toxin injection in 8 and prior myotomy in 1. Primary complaints were dysphagia-100%, respiratory-20%, weight loss-46%, and pain-31%. Mean esophageal diameter was 5.94 cm and tortuosity was present in 10% of patients. In the operating room all patients underwent endoscopic exam and evacuation of retained esophageal contents. The esophagomyotomy was routinely extended to the level of the lower pulmonary vein and inferiorly to one cm beyond the lower esophageal sphincter. VATS and LAP procedures were successfully performed in all patients. Mean operative time was 172 minutes and hospital stay averaged 2.5 days. There were no operative mortalities. Operative complications consisted of 3 perforations identified intraoperatively and repaired endoscopically. Primary symptoms were improved in 96% of patients with mean dysphagia scores(range 0-10) changing from 8.8 to 0.73 (p = 0.001) at a mean follow-up 8.4 months. Post-op management included dilation in 3 patients and 2 patients required esophagectomy. Post-op reflux symptoms have been noted in 11% (2/19) of VATS and 6% (2/35) LAP patients. At this intermediate analysis, video-assisted approaches to correction of achalasia appear to be a reasonable alternative to extended medical therapy or open surgery. Conversion to an open approach should be considered when technical mishap or compromise of therapeutic benefit is of concern. Thoracic surgeons interested in this esophageal motor disorder should become familiar with these surgical approaches.

§1986-88 AATS Edward D. Churchill Research Scholar

*By invitation