Tuesday Afternoon, May 7, 1957

2:00 P.M. Scientific Session: REGULAR PROGRAM-Grand Ballroom.

38. Ventriculoplasty for Cardiac Aneurysm.

C. P. Bailey, H. E. Bolton (by invitation)

and R. A. Oilman (by invitation), Philadelphia, Pa.

Ventricular aneurysm is a complication variously estimated to occur in 5 to 20 percent of patients who suffer an acute myocardial infarction. It is believed that each year 500,000 to 1,000,000 Americans suffer from such episodes.

Ventricular aneurysm also may be caused by trauma (accidental or from cardiac surgery), or by congenital malformation of the heart. However, the physiological effects of these latter two types of lesions differ significantly from those of the post-infarctional ones.

The effect of the paradoxical pulsations of the aneurysmal mass upon the over-all cardiac function is profoundly deleterious, simulating the effect upon respiration of severe paradoxical breathing. Death results, in medically treated cases, from progressive loss of myocardial competence and eventual heart failure. Thrombo-embolic phenomena may dominate the clinical picture and, in some instances, is the chief cause of death. Actual rupture of the aneurysm is extremely rare.

The logical definitive treatment of this lesion would seem to be surgical excision of the abnormal cardiac bulge. There are two specific hazards in this surgical undertaking to be averted. These are: (1) possible dislodgment of thrombotic material from the lumen of the aneurysmal sac into the systemic circulation during the necessary surgical manipulations; (2) congestive heart failure precipitated by extreme reduction of the left ventricular capacity due to excessive resection of the scarred portion of the ventricular wall. The first pitfall may be avoided by the use of a special "flush-out" technique in which the fundus of the sac is incised before closure of a special dentate clamp previously applied to its base. The second danger may be obviated by limiting the ventricular resection to the region of the "bulge" itself, no attempt being made to excise the entire area of previous infarction.

Since the first such operation in April, 1954, seven additional patients have been operated for this condition at our clinic. Seven of the eight have survived and have experienced a generally satisfactory postoperative course.

In view of the improvement obtained by this type of surgery, it is felt that this relatively common and extremely dangerous mechanical condition of the heart wall indicates surgical correction by subtotal resection of the sac. It is important that this should amount essentially to a "tailoring" of the eccentrically dilated left ventricular chamber to one of normal size and shape-a "Ventriculoplasty" rather than to total excision of the entire area of myocardial scarring.

39. Visual Repair of Congenital Aortic Stenosis During Hypothermia.

Henry Swan, S. Gilbert Blount, Jr. (by invitation)

and Robert H. Wilkinson (by invitation), Denver, Colo.

About a year and a half ago, an operative technique was developed to permit direct vision procedures upon the aortic valve or the outflow tract of the left ventricle through an incision in the aorta just above the valve. Resection of subvalvular stenosis or aortic valvuloplasty is accomplished during circulatory occlusion in the hypothermic patient and a safe operative time of six minutes is achieved.

Thirteen patients with congenital aortic stenosis have been operated upon by this technique. Eleven were valvular while two were subvalvular. One patient died four weeks after operation of mediastinitis; the others have done well. The diagnostic criteria, operative findings, and the results of the operation in these patients will be described. In the light of these findings, an evaluation of this operative procedure will be presented. Variations in the pathology of the anomaly have considerable bearing on the excellence of the results achieved.

40. Surgical Treatment of Stenotic or Regurgitant Lesions of the Mitral and Aortic Valves by Open Cardiotomy.

C. Walton Lillehei, Richard A. DeWall (by invitation), Vincent L. Gott

(by invitation) and Richard L. Varco, Minneapolis, Minn.

Rapidly increasing experience with the pump-oxygenator for congenital cardiac malformations has resulted in confidence concerning the well being of the patient during an interval of total cardiopulmonary by-pass. It was natural, then, that the open operation in which the surgeon sees precisely what has to be done, and proceeds to do it under direct vision would be extended to diseases of the mitral and aortic valves heretofore customarily treated by blind or closed techniques.

A steadily increasing series of patients with stenotic, regurgitant, or combined lesions of these valves are being managed by open cardiotomy utilizing the pump-oxygenator. The surgical techniques developed as well as the results obtained for the various types of lesions will be presented.

41. The Surgical Correction of Aortic Insufficiency.

Warren J. Taylor (by invitation), Wendell B. Thrower (by invitation),

Harrison Black and Dwight E. Harken, Boston, Mass.

The morphologic and hemodynamic nature of aortic insufficiency is reviewed.

The rationale of corrective procedures is discussed. The objectives and shortcomings are presented.

Reduction of incompetence by circumclusion of the base of the aorta below the coronary arteries will be discussed. The hemodynamic effect of this operation will be reviewed.

42. The Clinical and Physiological Criteria for the Surgical Correction of Mitral Regurgitation.

Julio C. Davila (by invitation), P. Jumbala (by invitation), Robert G. Trout

(by invitation) and Robert P. Glover, Philadelphia, Pa.

Circumferential suture of the mitral valve for correcting mitral regurgitation has afforded an opportunity to study various phenomena before and after correction of this lesion.

That mitral regurgitation is corrected by this method has been documented in previous publications. The data obtained on experimental and clinical material, includes, intracardiac pressure-pulse tracings, phonocardiograms, roentgenograms, animal and human necropsy findings and, in addition, objective and subjective findings in patients who have undergone the operation and have been followed for as long as 29 months. Visual evidence of the anatomic and mechanical effect of the procedure has been recorded cinematographically with the use of the pulse-duplicator demonstrating the correction of the dysfunction beyond question.

This presentation is an analysis of the objective data obtained during the past twenty-nine months of clinical application of this procedure. This information is correlated with the clinically observed results of surgery. Useful criteria for the study of patients with this lesion and preliminary surgical indications are suggested. Certain conclusions as to the value of specific hemodynamic findings and the changes in these after operation are presented.

On the basis of experimental and clinical studies the possible usefulness of inferior vena cava ligation as an adjunct in the operative treatment of mitral regurgitation is discussed.

43. The Application of Hydraulic Principles to the Coronary Circulation.

Bernard L. Brofman (by invitation) and Claude S. Beck, Cleveland, Ohio

The current enthusiasm and wide-spread application of various forms of surgical operation for coronary artery disease calls for a critical definition of the problem and a re-appraisal of fundamental (and often disregarded) hydraulic principles which govern coronary flow. This report is based on hydraulic model experiments, coronary flow measurements in the dog, and the study of patients operated for coronary artery disease. These observations have been summarized graphically to demonstrate flow-pressure relationships in the coronary circulation in the normal and in hearts with various degrees of coronary obstruction, with special reference to such factors as drugs, exercise, perfusion pressure, and intercoronary communications.

Flow-pressure relations in the coronary circulation are those of a high-resistance circuit in which normally the determinant of volume flow is not the cross-sectional area of the coronary arteries but the artenolar resistance. Gradual narrowing of a coronary artery is readily compensated for by a proportional reduction of artenolar resistance until a critical level is reached, at which point the decreased cross-sectional area of the coronary artery becomes the determinant of flow.

The patient with clinical evidence of coronary artery disease has a critically-compensated, precariously-balanced circulation. A slight further reduction in flow (or increase in metabolic requirement) may be catastrophic; whereas a relatively small increase in blood supply to an ischemic area (such as provided by operation) is remarkably effective in restoring balance and producing dramatic clinical improvement.