Experiences with Myocardial Revascularization By Division of the Internal Mammary Arteries

¹ The Departments of Thoracic and Cardiac Surgery, and Cardiology, The Presbyterian Hospital; Fitzgerald Mercy and Lankenau Hospitals; The Thoracic and Cardiovascular Research Laboratory at Presbyterian Hospital; The Glover Clinic.

1. A critical although purely preliminary attempt has been made to assess the value of bilateral ligation and division of the internal mammary arteries as a means of increasing blood supply to the myocardium. The concept for this approach is that of Fieschi. Battezzati, Tagliaferro and DeMarchi have been responsible for reintroducing and amplifying this original concept. By and large the studies reported in this discussion confirm the findings of these Italian investigators. At the moment, however, considerable reservation as to the ultimate place of this surgical procedure is warranted. Whether it will eventually remain as a surgical entity on its own merits or will be used as an adjunct to other surgical techniques cannot be decided until much more investigative work, both experimental and clinical, has been carried out.

2. That there is a naturally developing extracardiac communication between the coronary arterial and pericardiophrenic arterial vasculature has again been confirmed.

3. As yet there is no experimental proof that ligation of the internal mammary arteries bilaterally at the level of the second interspace actually increases blood flow to the heart although the supposition that it does is entertained.

4. There is the decided suggestion that in dogs ligation of the internal mammary arteries provides a measure of myocardial protection to the subsequent production of acute coronary occlusion by ligation of the anterior descending coronary artery at its origin.

5. Ligation of the internal mammary arteries at the second interspace is followed by an increase in mean arterial end pressure above the point of ligature in dogs.

6. Ninety-two patients suffering from arteriosclerotic and hypertensive cardiovascular disease with organic coronary insufficiency and angina pectoris have been subjected to bilateral mammary artery ligation (BIMAL). The angina pectoris in three of these patients was secondary to advanced aortic valve disease. Fifty of these patients have been carefully followed for one to five months. By conservative clinical evaluation 34 (68 per cent) of these patients have either lost their symptoms of pain (18—36 per cent) or have been immeasurably relieved of their discomfort (17—32 per cent). The remainder were unimproved.

7. Objective evidence of clinical improvement lags well behind the observed clinical improvement. In 13 (26 per cent) the electrocardiographic tracings taken one month or more after surgery show obvious improvement and the same may be said in nine (18 per cent) of the ballistocardiographic studies obtained. As this evidence of improvement occurred on only one occasion in the same patient, objective signs for the better have occurred in 22 (42 per cent) patients. We are indebted to and acknowledge the very considerable help rendered by Dr. Isaac Starr, Hartzell Research Professor of Therapeutics, University of Pennsylvania Medical School, who supervised and read all ballistocardiograms.

8. A simple technique for the performance of Division of the Internal Mammary Arteries has been detailed.