Wednesday Afternoon, May 9,1956

2:00 P.M. Scientific Session: REGULAR PROGRAM

38. Observations on the Surgical Pathology of Congenital Intra-cardiac Defects Made During Direct Vision Repair.

Herbert E. Warden (by invitation), Richard L. Varco and

C. Walton Lillehei, Minneapolis, Minn.

More than 100 patients with congenital intracardiac anomalies have undergone direct vision repair of their defects during total cardiac by-pass by means of controlled cross circulation, the arterial reservoir, biologic (dog lung) oxygenator, or a mechanical (bubble) oxygenator perfusion techniques.

The most common congenital defects approached with these methods have been interventricular septal defect (65%), tetralogy of Fallot (20%), and atrioventricularis communis (7%). This experience in the corrective surgical treatment of these lesions has emphasized certain features of the pathologic anatomy of these anomalies which are of utmost importance to successful repair and recovery of the patient.

In addition, as experience has grown during the course of treatment of these patients, several important modifications in the technique of repair have evolved. These as well as the details of the pathologic anatomy of the most common congenital intracardiac defects will be presented.

39. Technique for Repair of Ventricular Septal Defects Utilizing Extracorporeal Circulation.

John W. Kirklin, H. G. Harshbarger (by invitation), D. E. Donald (by invitation)

and J. E. Edwards (by invitation), Rochester, Minn.

A new operative procedure undergoes changes in technical details with the accumulation of experience. It is the purpose of this presentation to present the details of the surgical aspects of closure of ventricular septal defects.

Thirty cases with ventricular septal defect, twenty-one as an isolated lesion, two as a part of common atrioventricular canal, and seven as part of the tetralogy of Fallot have been operated at the Mayo Clinic by open cardiotomy utilizing the Gibbon-type pump-oxygenator for extracorporeal circulation. Data from these cases and from cases operated subsequent to submission of this abstract will be presented.

The pathologic anatomy of the various types of ventricular septal defects encountered in this series will be discussed. Three types of defects have occurred in patients with this as an isolated anomaly. The type of defect seen in the tetralogy of Fallot is different from any of these.

Details pertinent to the closure of each of these types of defects are emphasized. The actual steps in the operative repair which has been found to be best for these defects will be illustrated. Studies pertaining to the completeness of the closure will be presented.

40. The Use of the Heart-Lung Apparatus in Human Cardiac Surgery.

F. D. Dodrill, Norman Marshall (by invitation), Jan Nyboer (by invitation),

Elsie Noe (by invitation), C. H. Hughes (by invitation)

and A. B. Stearns (by invitation), Detroit, Mich.

We have previously reported our experimental results of the heart-lung apparatus. We have demonstrated that the blood can be well arterialized and can be returned to the arterial system with maintenance of a satisfactory blood pressure. Two innovations have since been instituted in the plan of the surgical procedure: (1) Removal of a portion of the circulating blood, keeping it outside the circulation while the body is maintained on donor blood; (2) Arterialized blood is returned directly to the recipient's aorta without the use of the subclavian artery.

After the pumping period is over, the original blood of the patient is returned to the circulation while the used blood is simultaneously removed. Blood volume studies show that at least one-third of the blood volume may be removed. The removal of the patient's own blood is done simultaneously with the administration of donor blood to maintain the blood pressure. Likewise, as the used pump blood is removed from the vascular system, the original blood is simultaneously returned to the body.

Using the apparatus which we have previously described and with the above changes, we have successfully applied these methods to human cardiac surgery. A more detailed analysis of the human surgery will be given.

41. The Treatment of Mitral Insufficiency by the "Purse-String" Technique.

Robert P. Glover, Julio C. Davila (by invitation) and

O. Henry Janton (by invitation), Philadelphia, Pa.

The concept for reducing the size of the annulus in valvular insufficiencies as a method for the correction of this dysfunction has been presented in previous publications. Compared to the principle of replacement of occluding valvular elements, the reduction of the valvular ring by circumferential suture has several theoretical and practical advantages. This is especially true when applied to the mitral valve. These advantages are: This procedure does not require the introduction of foreign materials across the cardiac chambers; it makes use of all remaining valvular substance capable of function; the effective orifice of the atrioventricular communication is not encroached upon by plugs or sutured cusps; it involves no more intra-cardiac manipulation than does a commissurotomy and results in no significant myocardial trauma; it is plausible to expect that the size of the atrioventricular ring will not progressively enlarge.

This principle, with or without concomitant commissurotomy, appears applicable to most forms of mitral insufficiency. Having demonstrated the anatomical feasibility of circumferential suture of the mitral ring and tested its application experimentally both on the normal and regurgitant valve over a period of two years, a thorough clinical trial seemed indicated. Therefore, the procedure has been performed on twenty patients, the oldest two of which are now over a year postoperative. Only stage IV patients were selected, each having been in marked chronic congestive failure for several years (most of them terminal cases). It was realized from the outset that such patients in the main could not possibly obtain outstanding results but it seemed imperative to study the efficacy of the procedure applied to the Rheumatic Heart and some hope of reasonable salvage was likewise entertained.

The technique used, the results obtained and the indications for further employment of the operation will be discussed.

42. Mitral Insufficiency-Treatment by Polar Cross-Plication of the Annulus Fibrosus.

Henry T. Nichols (by invitation), Philadelphia, Pa.

During the past six years, efforts have been made by various investigators to correct or relieve mitral insufficiency by various surgical methods. These have included attempts to overcome the effective deficiency of valvular substance by placement of prosthetic forms within or alongside the valve structures; by grafting new living tissue to the shortened leaflets; by suturing together the divergent portions of the shortened cusps. More recently others have attempted by suture plication, by circumferential constriction, and by deformation of the annulus fibrosus to favor coaptation of the partially retracted free leaflet margins. It is believed by the author that this latter principle is sound but that the technique of applicaion may be improved upon.

The logical attack upon the annulus must be designed to reduce selectively the diameter of the ovoid channel bounded by the ring across the incompetent pole of the valve (usually the posterior). This effectively brings the bases of the shortened leaflets closer together. Hence, the divergent free margins are brought closer together thus being rendered more capable of systolic coaptation. A simple and apparently safe technique has been worked out for suturing together suitable selected points upon the mural and septal portions of the annulus.

On August 16, 1955, the first clinical attempt was made in a patient with a serious grade of mitral insufficiency. Since then, 16 other patients have been operated by this method. In every one it was possible to demonstrate a remarkable immediate reduction in the size of the digitally palpable regurgitant jet. There have been three postoperative deaths, each from an apparently avoidable complication. With one exception the initially obtained auscultatoiy improvement has been maintained and in this latter group the clinical benefit has been striking. These patients have been investigated carefully both pre and postoperatively and the objective evidence of benefit, so far, have been corroborative.

43. Patent Ductus Arteriosus in Infancy.

S. Richard Bauersfeld (by invitation), Paul C. Adkins (by invitation)

and Edward M. Kent, Pittsburgh, Pa.

The typical case of patent ductus arteriosus causes little or no trouble during infancy. Occasionally, however, a large patent ductus may produce severe strain on the circulation during early infancy. Here, specific diagnosis is essential and prompt surgical closure of the patent ductus is indicated. During infancy and under certain other circumstances, the pressure differential between aorta and pulmonary artery is slight and only a systolic murmur is heard. Hence, a diagnosis of patent ductus arteriosus is difficult to establish without special studies.

In 65 cases of confirmed patent ductus arteriosus during the past three years, 19 (29%) were under the age of 24 months and were subjected to operation. All 19 showed poor weight gain, had intermittent respiratory difficulty, and showed evidence of cardiac enlargement. In, ten of these infants, a continuous murmur was not audible and a systolic murmur alone was heard. Differentiation between patent ductus arteriosus and interventricular septal defect often could not be made on the basis of the usual examinations. Ductal patency was established by retrograde aortagrams.

No surgical deaths occurred although two infants died three months after leaving the hospital. Postoperative follow-up of the remaining cases shows that all except one of these infants have gained weight. AH have been less prone to respiratory infections and in general have done well.