Sunday Morning, May 18, 1958

8:30 A.M. Scientific Session: REGULAR PROGRAM -Imperial Ballroom.

30. Open Operation for Mitral Insufficiency.

Donald B. Effler, Laurence K. Groves, William V. Martinez (by invitation)

and Willem J. Kolff (by invitation), Cleveland, Ohio

Increasing experience with the pump oxygenator has permitted a relatively safe approach to the mitral valve. Whereas, there is little reason to utilize such a technique in the treatment of mitral stenosis, it does have real value in the treatment of mitral insufficiency.

The authors have encountered two major types of mitral insufficiency: congenital and acquired.

The congenital type of mitral insufficiency may be associated with an atrial defect of the ostium primum type. Failure to recognize the mitral insufficiency at the time of surgical closure may result in congestive failure. The authors' experience and technique in the transatrial correction of combined mitral insufficiency and ostium primum defect is described.

The acquired forms of mitral insufficiency encountered at surgery are most frequently caused by rheumatic fever. The etiology, however, is of less importance than the topography of the diseased valve. Mitral insufficiency may be represented by ruptured chordae tendineae, dilatation of the annulus, destruction and distortion of either valve cusp, and by surgical accident in the treatment of pure mitral stenosis. Operations for correction of mitral insufficiency were first attempted through the left atrial appendix utilizing the pump oxygenator and elective cardiac arrest (Melrose technique). Recent experience with the pump oxygenator utilizing the right sided approach, with or without elective cardiac arrest, has shown distinct advantages. The operation is performed by a right thoracotomy alone utilizing retrograde cannulation of the left common femoral artery. The exposure is good and postoperative complications reduced. The authors' experience and techniques are detailed.

31. Direct Vision Correction of Mitral Regurgitation.

Earle B. Kay and Cid Nogueira (by invitation), Cleveland, Ohio

Many ingenious techniques have been devised during the past few years for the surgical correction of mitral regurgitation, none of which have been wholly successful. The obvious disadvantage in the past has been the inability to achieve complete or permanent correction of the insufficiency by closed or blind techniques. The application of direct vision techniques, utilizing a mechanical pump oxygenator, for the correction of mitral regurgitation was a natural development in this field, similar to the transition from closed to open techniques that has taken place in the surgical correction of other cardiac lesions.

In the developmental phase of any new surgical technique many aspects of the problem have to be tried and evaluated. Much of this can be accomplished in the experimental laboratory. However, the final evaluation is dependent upon the results of clinical application. The main problems, apart from those inherent in extracorporeal circulation and perfusion techniques associated with the open technique in the correction of mitral regurgitation, are the approach or exposure, the control of air embolism, the advisability of elective cardiac arrest, and the technical correction of the insufficiency.

Eleven patients with mitral valvular disease have now been operated upon. Eight of the patients had mitral regurgitation and three mitral stenosis. A left-sided approach was employed in four, and a right-sided approach in seven. Elective cardiac arrest has been employed in seven and in four the operative correction was performed with the heart beating. The advantages and disadvantages of the various exposures and the advisability of cardiac arrest will be discussed. At the present it is felt that the right-sided approach allowing the heart to beat will be associated with the greatest degree of success. In this group there was only one operative death, the first in the series.

32. Satisfactory Surgical Correction of Pectus Excavatum Deformity in Childhood - A Limited Opportunity.

Kenneth J. Welch (by invitation), Boston, Mass.

From 1951 to 1958, 138 children with moderate to severe pectus excavatum deformity have been evaluated with regard to the desirability of surgical correction. Seventy-six patients have been considered suitable candidates and have been operated upon by the author. The first thirty-seven patients were operated upon between 1951 and 1955, using the Sweet multiple chondrotomy technique. The second group of thirty-nine patients was operated upon employing a modified Garnier-Lester-Ravitch technique during the period 1954 to 1957. The average age at the time of operation, in both groups, was 3.7 years.

A concept of etiology (chondro-dystrophy) and a plan of therapy is outlined. Detailed physiologic data on twelve patients, ranging in age from two to twelve years, is presented, including pre and postoperative pulmonary function and cardiac catheterization studies. Growth studies have been carried out in selected cases.

It is concluded that surgical correction of pectus excavatum deformity is desirable and effective in a limited age group - two to five years.

a. It is unnecessary and more hazardous (if adequately performed) in patients less than twenty-four months of age.

b. It is of little value after the age of five years, in terms of objective improvement.

c. The risk of operation is minimal in this age group and this risk is defined by: (1) The hazard of a one-and-a-half to two-hour endotracheal general anesthesia in a temporarily flail chest; (2) the accuracy of whole blood replacement in this same period of gravimetrically estimated amounts, in the range of 250 to 500 cc.; (3) the danger of surgically-introduced infection which can be minimized by the avoidance of external traction devices and inadvertent unilateral or bilateral thoracotomy.

33. Pectus Excavatum: An Appraisal of Surgical Treatment.

Paul C. Adkins (by invitation) and Owen Gwathmey, Washington, D. C.

A review of thirty-nine patients seen with a pectus excavatum deformity during a four year period is presented. In twelve patients the operation was deferred to a later age, or was not indicated because of minimal deformity. Twenty-seven patients were subjected to various operative procedures for correction of the defect. The technical aspects of the operative procedure are discussed briefly and the necessity of individualization of each case is emphasized. The indications for the use of the minimal procedure of excision of the xiphoid and division of the substernal tendon in infants under the age of one year are given. The necessity for postoperative physiotherapy for correction of residual postural defects is emphasized. A critical evaluation of the over-all results in the twenty-seven operated cases is presented. The best results were obtained by plastic reconstruction of the sternum and costal cartilages with the use of a homologous rib graft as a strut.

34. Hypoventilation, Hypoxia and Acidosis Occurring in the Acute Postoperative Period.

R. Maurice Hood (by invitation) and Arthur C. Beall, Jr

(by invitation), Oakland, Calif.

Sponsored by Frank Gerbode, San Francisco, Calif.

Hypoventilation during open chest operations, with resultant carbon dioxide retention and respiratory acidosis, has received considerable attention; however, comparatively little interest has been manifested in this problem during the acute postoperative period. The present investigation was undertaken to determine the ventilatory efficiency during this period and its result on arterial oxygen saturation, carbon dioxide levels, and pH.

Forty patients were studied. Thirty were patients undergoing intrathoracic procedures; ten were having major abdominal operations. These were unselected but not consecutive cases. Samples of arterial blood were obtained prior to surgery, before removal of the intratracheal tube, and at fifteen-minute intervals for one hour thereafter. Each sample was analyzed for arterial oxygen (O₂) saturation and carbon dioxide (CO₂) content, and the pH of each sample determined. At the time of removal of each sample, a two-minute spirogram was made, and the tidal volume and minute ventilation were calculated.

The results were analyzed statistically and individually. Fifty per cent showed a significant reduction in arterial pH occurring after surgery. The same patients showed an increase in arterial CO₂ content. Twenty per cent showed a decrease in O2 saturation below 85 per cent during the hour of observation. Spirograms vividly demonstrated the basis for hypoxia, CO₂ retention, and acidosis. Not infrequently the tidal volume dropped below 300 cc and approached the level of the anatomic dead space. Spirograms revealed, in addition, periods of apnea and irregularity of individual breath excursions.

The writers are of the opinion that postoperative hypoventilation with its resulting metabolic changes may be as significant as that occurring during surgery. Slides illustrating statistical results and several individual cases will be shown. Etiological factors and corrective measures will be discussed.

35. Clinical and Hemodynamic Evaluation of the Surgical Correction of Aortic Stenosis.

Dwight E. Harken, Harrison Black, Warren J. Taylor (by invitation),

Wendell B. Thrower (by invitation), Harry S. Soroff (by invitation),

Steven Lunzer (by invitation) and Roy H. Clauss (by invitation),

Boston, Mass.

Experience with various operations to correct aortic stenosis, including trans-ventricular valvulotome fracture dilatation, open aortic operation and various closed transaortic operating tunnel techniques has varied from moderately encouraging to disastrous throughout the world. A critical analysis of an operation that we have used recently encourages us.

This report on 100 consecutive transaortic operations using an Ivalon tunnel points up pathologic hemodynamic and technical factors that influence the quality of repair. The quality of repair and mortality have steadily improved throughout the series. There have been but three deaths in the last 65 operations, and two of these three patients were operated in overt congestive failure (e.g., an end diastolic pressure of 45 mm. Hg. and bilateral hydrothorax). Many patients in congestive failure did not succumb. Even this type of terminal patient can attain encouraging clinical and hemodynamic improvement.

The limiting factors to totally satisfactory correction of aortic stenosis will be presented and prosthetic valves discussed.

36. The Surgical Treatment of Anomalous Pulmonary Veins.

Henry T. Bahnson and Frank C. Spencer (by invitation),

Baltimore, Md.

Eighteen patients with anomalies of the pulmonary venous return have been treated with open intracardiac surgery. Hypothermia was used in fifteen patients and extracorporeal circulation in three. There were fifteen survivors and three deaths.

Eleven patients had all or part of the right pulmonary veins entering the right atrium in conjunction with an atrial septal defect. The anomalous drainage was corrected during closure of the atrial defect by transposing the atrial septum so that the veins entered the left atrium.

Seven patients had a total anomalous drainage of the pulmonary veins. The veins entered the left innominate vein in two patients, the superior vena cava in three patients, and the coronary sinus in three patients. Anomalous drainage into the superior caval system was corrected by partitioning the superior cava or right atrium so the veins drained through an atrial septal defect into the left atrium. The anomalous drainage into the coronary sinus was treated by excising the partition between the coronary sinus and the left atrium.

The anatomical abnormalities and the methods of surgical correction will be discussed and illustrated.