MONDAY MORNING, MAY 1, 1972

8:30 A.M. Business Session (Limited to Members)

Los Angeles Ballroom

8:45 A.M. Scientific Session: REGULAR PROGRAM

Los Angeles, Ballroom

1. A Five-Year Study of Viable Aortic Valve Homografts

WILLIAM W. ANGELL*, Palo Alto, California and

NORMAN E. SHUMWAY, Stanford, Calif.

In a series of 378 patients, fresh aortic homografts were implanted into all intracardiac positions. Function of the 408 grafts has been followed over a five-year period. The technique of preparation appears to account for a failure rate which is low when contrasted to most reported series of tissue valves. We have attempted to utilize the grafts in a viable state and tissue culture and histology support the concept that there are persistent viable cells in the homograft cusp.

Viability is determined at the time of procurement and again at implantation by in vitro tissue culture of the valve cusp fibroblasts. Preoperative frame mounting is employed in all cases except those patients with a small aortic root. Three percent of patients died of valve related causes. Actuarial curves show 5-year survival at 86%. Eight percent more of patients have required reoperation for valve failure, making a total 5-year valve survival of 89%.

Analysis of these data and correlated experimental work leads us to three conclusions: 1) the fresh aortic homograft still holds promise as the best and safest cardiac valve replacement; 2) the low valve failure rate over a significant interval is probably related to use of fresh homografts; 3) the influence of viability on long term function remains to be further elucidated.

*By Invitation

2. Aortic Fascia Lata and Pericardium Valve Replacement: 3 Years Experience With 100 Cases

MARIAN I. IONESCU*, BROJOESH C. PAKRASHI*,

MICHAEL P. HOLDEN*, GEOFFREY H. WOOLER*, Leeds, England

Sponsored by Harris B. Shumacker, Jr.

One hundred patients had aortic valve replacement with a three-cusp, frame-mounted graft made of autologous or homologous fascia lata or of heterologous pericardium.

The follow-up period extends over 36 months. The incidence of both hospital and late mortality was 10%, with myocardial failure and bacterial endocarditis as significant etiological factors.

Considerable symptomatic improvement was obtained by all but 3 surviving patients. There was a statistically significant reduction in card 10-thoracic ratio and in the voltage of the E.C.G.

An aortic diastohc murmur was noted in 1 case within 10 days of surgery. It is considered to be due to insertion of a mechanically imperfect graft. The graft was removed 8 months later.

Eight patients developed aortic diastohc murmurs between 1 and 8 months post-operatively. The murmurs are non-progressive and regurgitation is haemo-dynamically insignificant.

Thrombo-embohc complications and haemolysis have been absent. Anticoagulants were not used.

The performance of the grafts was evaluated by angiography and pressure recordings and by "in vitro" hydrodynamic studies, high-speed cinematography, compression and tensile strength measurements and biochemical investigations. Relevant data from these studies is presented.

These grafts in the aortic position have shown good performance, with no emboli and no graft failure, over a period of 3 years.

*By Invitation

3. Longterm Evaluation of Cloth-Covered Metallic Ball Prostheses

O. WAYNE ISOM*. C. DAVID WILLIAMS*, EMILY A. FALK*,

and FRANK C. SPENCER, New York, New York

Over a period of four years (October 1967-September 1971), 318 cloth-covered Starr-Edwards metallic ball prostheses (aortic models: 2300, 2310, 2320 and mitral models: 6300, 6310, 6320) were inserted in 281 patients. Most were Class III or Class IV (NYHA). Patients requiring additional cardiac procedures were not included in this analysis. A uniform operative technique, including a Temptrol bubble oxygenator, moderate hemodilution and hypothermia, induced ventricular fibrillation, and intermittent coronary per fusion was employed.

Operative mortality (within 30 days) and late mortality were:

Over one-half of the late deaths were in Class IV patients from heart failure or arrhythmias.

A continuous semi-annual followup has found that most patients have an excellent functional result. Complications are few: thromboembolism 2%; severe hemolysis 1.5%; endocarditis 2%, penvalvular leakage 2%, and cloth erosion 1%. A Dacron pledget buttress technique has virtually eliminated perivalvular leakage. Results and complications have improved even further with the 2320 and 6320 model valves. These experiences and results will be presented in a statistical life-table form.

*By Invitation

4. Spinal Cord Complications Following Surgery for Co-arctation of the Aorta

LYMAN A. BREWER, ID, Los Angeles, Calif., RICHARD G. FOSBURG*,

San Diego, Calif., JOSEPH J. VERSKA*, and

G. ARNOLD MULDER*, Los Angeles, California

In 1968 one of us (LAB) successfully defended a medical legal suit in a case of paraplegia following resection of a coarctation of the aorta. At that time, few such cases had been reported. Since the experience of any one surgeon with this complication is thankfully limited, a broad survey was undertaken, resulting in the accumulation of important data made possible by the generosity of colleagues throughout the world.

To date 56 surgeons or groups have reported approximately 11,000 surgical cases with 41 cord paralyses. Of the 20 cases of paraplegia associated with coarctation of the aorta identified in the literature, 6 have occurred without operation. The modifying factors discussed include variations in the anterior spinal artery, state of collateral circulation, number of intercostals divided, and cross-clamping time.

The role of hypothermia, left heart by-pass, and jump grafts employed to protect the spinal cord is given. Observations on possible causal factors, prevention, and management are made from this world-wide survey and the literature. To the practicing surgeon, one very significant observation emerges: In certain instances paraplegia will occur in spite of every effort to avoid it, apparently from deficiencies of the anterior spinal artery.

*By Invitation

5. The Role of Mediastinoscopy in the Selection of Treatment for Bronchial Carcinoma with Superior Mediastinal Lymph Node Involvement: A 7 Year Experience

GRIFFITH F. PEARSON, WILLIAM M. NELEMS*, ROBERT D.

HENDERSON*, and NORMAN C. DELARUE, Toronto, Ontario, Canada

In 454 patients with presumably operable bronchial carcinoma, mediastinos-copy disclosed spread to superior mediastinal nodes in 143 instances (31.5%). In the remaining 311 patients with "negative" mediastinoscopy the resectability rate was 95%, operative mortality 2.9%.

In 113 of 143 patients with "positive" mediastinoscopy, the nature of mediastinal spread was considered evidence of "biological inoperabihty" for the following reasons: small cell carcinoma (38), extranodal spread and local fixation (30), high right pretracheal spread (25), contralateral spread (20).

30 patients with ipsilateral mediastinal node involvement were selected for preoperative irradiation and resection. 13 of 30 were irradiated but never resected. 9 developed recognizable hematogeneous spread in the interval preceding resection, and 4 refused operation. 12 of these 13 died of tumour (median survival 9 months), and one is alive at 72 months. 17 patients reached thoracotomy, and of 16 resected 2 died postoperatively, 8 died of tumour (median survival 21 months), 5 are living and well, and 1 is living with local recurrence. In 26 patients selected for irradiation and resection, who had ipsilateral spread from squamous carcinoma, the 5 year survival was 20%.

These findings support the use of mediastinoscopy in assessing operability. Resection is recommended for squamous tumours with ipsilateral mediastinal spread.

*By Invitation

6. Factors Influencing Survival After Resection for Bronchial Carcinoma

THOMAS W. SHIELDS, Chicago, Illinois, GEORGE A. HIGGINS*

and ROBERT J. KEEHN*, Washington, D.C.

One thousand eight hundred and three patients in the VA Surgical Adjuvant Lung Cancer trials underwent a curative resection during the first ten years of study. These patients have been evaluated for factors predictive of recurrence within five years of the operation. Thirteen characteristics found in an earlier study to be significantly associated with five year survival were examined for independent predictive information using stepwise multiple regression analysis. Prediction of outcome was equally as good when based upon only four of the more important variables; extension of the tumor beyond the lung, involvement of mediastinal nodes, age of the patient, and the presence of another pulmonary disease.

The four variable predictive scores were computed and correlated with long-term survival. There were 752 patients whose predictive scores were less than the mean (more favorable), 696 patients with scores equal to or greater than the mean (less favorable), and 355 patients who had information missing for one or more of the four variables. Survival rates in patients with the more favorable scores were 37 per cent at five years and 24 per cent at 10 years compared with 19 and 11 per cent respectively in patients with less favorable scores. Survival rates in patients with unknown scores were slightly above that for patients with less favorable scores.

Of interest was the failure of cell type or size of the lesion to influence long-term survival. The significance of these findings will be elaborated upon.

*By Invitation

7. Sleeve Lobectomy for Carcinoma - A Ten-Year Experience

ROBERT J. JENSIK, L. PENFIELD FABER, FRANK J. MILLOY*

and JOSEPH J. AMATO*, Chicago, Illinois

Since 1961, 53 patients have undergone sleeve bronchoplasty resections for bronchogenic carcinoma. Three basic procedures were utilized: Right upper lobectomy sleeve resection in 26; left upper lobectomy sleeve resection in 19, left lower lobectomy sleeve resection in 8.

Thirty-seven patients received preoperative irradiation without significant effect upon morbidity and mortality.

In this group, there are 12 survivors, 8 over 5 years. In the non-irradiated group of 16 patients, there are 7 survivors, 3 beyond 5 years.

Indications for the application of this special resective procedure, morbidity and mortality data, and technical considerations will be discussed.

Salvage of lung tissue and the accomplishment of a five-year survival, ranging from 30% to 35% as plotted on an actuarial curve make this technique feasible and worthwhile.

8. Atypical Carcinoid Tumors of the Lung

PHILIP E. BERNATZ, MARCO G. ARRIGONI* and

LEWIS B. WOOLNER*, Rochester, Minnesota

A review of 215 patients with carcinoid tumors of the lung revealed that 23 had "atypical" tumors; the classification was based on a combination of features such as increased mitotic activity in a recognizable carcinoid pattern, nuclear abnormalities, disruption of architecture, and areas of necrosis. An association between these "atypical" care mo ids and aggressive biologic behavior was evident, 70% of the patients with the "atypical" form had metastasis, as compared to 6% of the patients with the typical carcinoid. This metastasizing potential has obvious implications for surgeons who may have been impressed with the benign nature of bronchial adenomas. The clinical, gross, and microscopic features in these cases support the concept that certain atypical carcinoids have great metastasizing potentialities and should be treated aggressively.

*By Invitation