MONDAY AFTERNOON, APRIL 6, 1970

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

International Ballroom Center

10. Ascending Aorta-to-Coronary Artery Saphenous Vein Bypass Grafts

Ben F. Mitchel, Maurice Adam,* and Gary J. Lambert,*

Dallas, Texas

Ascending aorta-to-coronary artery saphenous vein bypass grafts provide an immediate increase in myocardial blood supply for patients with ischemic heart disease. Because of this immediate effect, surgery can now be extended to those patients who were previously denied a revascularization procedure because of multiple vessel disease and/or poor myocardial function. To date, 133 bypass grafts have been used to augment myocardial blood flow in 80 patients. Thirty-six single, 35 double, and 9 triple bypass grafts were used. The grafts were taken to the right coronary artery (44 tunes), to the left anterior descending coronary (70 times), and to the circumflex coronary (19 times). In the last 60 cases internal mammary artery implants into the circumflex distribution have been abandoned in favor of direct circumflex surgery. Hospital mortality has been 10%. Graft failure, indicated by recurrence of symptoms and confirmed by angiography, has occurred in 6 patients (7.5%). The remaining patients (82.5%) are definitely improved, most markedly so. More striking has been the improvement demonstrated by some patients in myocardial contractility. Myocardial infarction may have been prevented by early bypass surgery in five patients diagnosed as having impending myocardial infarction. The longest follow-up is now 21 months.

11. Severe Segmental Obstruction of the Left Main Coronary Artery and Its Divisions: Surgical Treatment by the Saphenous Vein Graft Technic

Rene G. Favaloro, Donald B. Effler, Laurfnce K. Groves,

William C. Sheldon,* and F. Mason Sones, Jr.,* Cleveland, Ohio

Saphenous vein grafts have been used at The Cleveland Clinic Hospital since May 1967 Up to August 31, 1969 a total of 401 operations were performed. In 74 patients, there was severe localized obstruction in either the left main coronary artery, the anterior descending branch of the left coronary artery, or the circumflex branch of the left coronary artery. Bypass grafts from aorta to anterior descending or circumflex artery were used in almost all operations. In 12 patients, a simultaneous saphenous vein graft bypass was performed on the right coronary artery, and in 21 patients, a single internal mammary artery implantation was done. The hospital mortality was 6.5 percent. Postoperative coronary cineangiographic studies showed excellent perfusion of the coronary circulation through the graft. This new approach offers a solution for two lethal obstructions (1) severe narrowing at the main trunk, and (2) severe narrowing of the anterior descending branch above the first perforator branch. The previous technic (pericardial patch graft repair) was associated with an operative mortality of 65 percent when applied to the left coronary artery. Operative technic, indications, and pre- and postoperative selective angiography will be presented.

12. The Physiologic Parameters of Ventricular Function as Affected by Direct Coronary Surgery

W. Dudley Johnson,* Robert J. Flemma,* and

Derward Lepley, Jr., Milwaukee, Wis.

Direct reconstruction of coronary flow is now being accomplished in 97% of patients referred for surgery using single, double, or triple vein grafts. No "end-stage" patient has been refused on the basis of his heart condition alone. The recognition and correction of some pathophysiologic changes has allowed most "end-stage" patients to undergo surgery successfully. Blood volume deficiencies pre- and postoperatively are numerous, and the importance of an adequate volume and a normal hematocrit on ventricular function will be illustrated. To determine the physiologic changes induced by the increased coronary flow in an abnormal ventricle, a variety of studies have been performed on groups of patients pre- and postoperatively. These include ventriculography, atrial pacing, bicycle ergometry, cardiac outputs, measurements of ventricular contractility, and alterations in the ratio of the pre-ejection time to the total time of ventricular systole These studies will be summarized and indicate that in addition to relief of angina, significant improvement in function in late stage coronary patients can often be achieved. While the long-term results of vein bypass grafts to coronary arteries is uncertain, we feel these studies lend support to our vigorous surgical approach to coronary disease.

13. Arterial and Venous Microsurgical Bypass Grafts for Coronary Artery Disease

George E. Green,* Frank C. Spencer, and David A. Tice,

New York, N.Y.

From February 1968 to October 1968 coronary bypass grafts were attempted in 50 patients and completed in 47. The internal mammary artery was anastomosed to the anterior descending coronary artery (10 to 2.5 mm) in 25 patients, using a dissecting microscope (16 magnifications) and 9-0 nylon. In many of these patients the patent distal anterior descending artery could not be demonstrated by angiography but was found by dissection at operation. An aortic-coronary saphenous vein graft to either the anterior descending or the right coronary artery was carried out in the other 22 patients. Double grafts were performed in 22. Blood flow rates in the grafts averaged 50 to 65 ml/min. There were five hospital deaths. All but three of the surviving patients are virtually asymptomatic, and two of these three have thrombosed grafts. All of 11 mammary arteries studied by angiography 3 to 13 months after operation are patent. Two of four vein grafts, however, have been found thrombosed, with prompt recurrence of angina. The importance of the dissecting microscope to expand the applicability of bypass operations will be emphasized.

14. Complete Surgical Correction of the Totally Occluded and Diffusely Diseased Right Coronary Artery

G. Robinson, M. J. Kaplitt,* P. Philips,* and B. Patel,*

Bronx, N.Y.

In an attempt to provide immediate surgical relief to the ischemic heart attention has been directed to the aorto-coronary vein by-pass techniques in favor of endarterectomy. While the by-pass techniques appear to be successful in many instances they are often unsuitable because of inadequate runoff. Further, a long vein by-pass in fact by-passes a useful segment of artery, which if properly reopened might serve as a vast network for inter-coronary collateral formation. In the hope of effecting just such a complete surgical correction coronary gas endarterectomy was undertaken in the diffusely diseased right coronary artery. Six patients have been treated using this technique In each instance a multibranched specimen measuring from 10 to 14 centimeters was retrieved. Postoperative angiograrns demonstrate complete reconstitution of the entire coronary system with multitudinous side branches reopened. Operative time for the coronary surgery itself has not exceeded one hour. One patient recatheterized at one year demonstrates a patent 14 centimeter gas endarterectomy. It is our impression that coronary gas endarterectomy is the procedure of choice for total correction of the diffusely diseased right coronary artery.

15. Correlation of Mean Pulmonary Arterial Pressure with Results of Surgery for Non-restrictive Ventricular Septal Defects

Robert B. Wagner,* Jay L. Ankeney, and Jerome Liebman,*

Cleveland, Ohio

The operative mortality associated with closure of ventricular septal defects with systemic level pulmonary hypertension remains high In an attempt to establish better criteria for operability, a retrospective study of 30 consecutive patients undergoing closure of non-restrictive ventricular septal defects was carried out. Thirteen patients were females and 17 males whose ages ranged from two to 25 years. Preoperative pulmonary-systemic resistance (Rp/Rs), flow (Qp/Qs) and pressure (Pp/Ps) ratios, EKG, and pulmonary arterial mean pressures were correlated with operative results. All 15 patients whose mean pulmonary arterial pressure was 60 mm. Hg or less survived surgery with only one poor result due to persistent shunt. In contrast, eight of the 15 patients with mean pressures greater than 60 mm. Hg. died with low cardiac output syndrome within 48 hours following defect closure. Only four of these eight had Rp/Rs ratio of 0.45 or greater. Of the seven survivors, two have persistent left to right shunts, one died suddenly 40 days post-operatively, three have progressive pulmonary vascular disease, and only one has done well In this study, surgical results correlated best with preoperative mean pulmonary arterial pressure. Only one of 15 patients with a mean pressure greater than 60 mm Hg. benefited from closure of a non-restrictive ventricular septal defect.

16. Late Cardio-dynamics Following Correction of Ventricular Septal Defects with Previous Pulmonary Artery Banding

Paula Ebert,* Ramon V. Canent Jr.,* Madison S. Spach,* and

David C. Sabiston, Jr., Durham, N.C.

Pulmonary artery banding is an established technic for infants with refractory cardiac failure due to a VSD. Subsequent closure of the defect is also an accepted procedure, but little data are available concerning the ultimate hemodynamics which ensue. Twelve children with a VSD and previous banding have been corrected with a single death. The band was removed and a pencardial patch employed to enlarge the artery. Of significance are the late cathetenzation and cineangiography data obtained in eight patients. These show correction of the pulmonary stenosis with no significant gradient and demonstrate that the pulmonary-to-systemic resistance ratios remain unchanged from pre-bandmg levels (Pre-band 24 and post-correction 25). In addition, the results of four children with atnoventricular canal defects and banding will be discussed. The choice of an atrial or ventricular approach in the correction of these defects and the role of infundibulectomy will also be discussed in view of the postoperative results. The data show that pulmonary artery banding allows pulmonary resistance to remain unchanged until total corrective surgery can be performed. Ultimate results are quite favorable, and emphasis upon several points in the operative correction has proved of considerable importance.

17. Cor Triatriatum, Clinical Presentation and Operative Treatment

R.D. Brickman,* L. Wilson,* J.R. Zuberbuhler,* and

Henry T. Bahnson, Pittsburgh, Pa.

Cor triatriatum is an uncommon congenital cardiac anomaly in which the left atrium is divided by a fibromuscular septum into two chambers. The upper chamber or common pulmonary vein receives the pulmonary venous return, the lower chamber is the true left atrium and communicates with the left atrial appendage and mitral orifice. The membrane has one or more fenestrations which permit flow through this obstruction. The clinical presentation of this anomaly depends on the degree of pulmonary venous obstruction produced by this septum. Once thought a rare anomaly, it is now being recognized with much greater frequency. Diagnosis and definitive surgical correction of this defect depend on a high index of suspicion when a patient presents with a pulmonary venous obstruction. We have seen eight patients with this anomaly. The first five were either undiagnosed and untreated or misdiagnosed and unsuccessfully treated. The last three were both correctly diagnosed and treated with excellent results. Characteristics of the clinical presentation, physical signs, radiologic appearance, electrocardiographic findings, catheterization data, cineangiography, and correct surgical approach will be discussed. Representative examples from these cases will be used to illustrate this anomaly with appropriate slides and movies.

18. Late Results of Superior Vena Cava-Right Pulmonary Artery Shunt

I. B. Boruchow,* T. D. Bartley, L. P. Elliott,* M. W. Wheat, Jr.,

and G. L. Schiebler,* Gainesville, Fla.

Postopeiative (PO) cardiac catheterization and angiocardiography was performed in eight long-term (more than three years) survivors of SVC-RPA shunt. All had cyanotic congenital heart disease with decreased pulmonary blood flow. Clinical improvement was reflected by decreased hematocnt and increased arterial oxygen saturation (3 to 68%) and exercise tolerance. SVC pressure increased 2 to 10 mm Hg. In two patients, mild SVC syndrome beginning in the PO period was associated with over-all clinical improvement. Three patients with severe pulmonic stenosis as part of their malformation developed a late progressive form of SVC syndrome and clinical deterioration one and a half to two years after surgery. Disappearance of signs of SVC syndrome and clinical improvement followed Blalock-Taussig anastomosis (two cases), or open heart surgery (OH-S) (one case), leaving the SVC-RPA shunt intact. Improvement following OH-S of tetralogy of Fallot persists in spite of severe PO pulmonary valve insufficiency, elevated mean pressure in the left pulmonary artery (LPA), and systemic systolic pressures in the right ventricle and LPA. This paradoxical result may be due to the SVC-RPA shunt which reduced systemic venous return into the right heart.

*By Invitation