Monday Morning, April 17, 1950

9:00 A.M. Scientific Session.

11. Studies With Arteriovenous Fistulas. I. Response of the Normally Innervated and Denervated Heart to Occlusion of the Fistula.

H. B. Shumacker, Jr., M.D., L. W. Freeman, M.D.

(by invitation) and Leo Radigan, M.D. (by invitation)

Indianapolis, Ind.

Characteristically profound changes occur with occlusion of an arteriovenous fistula: slowing of pulse, rise in blood pressure and fall in cardiac output. Not only are these changes of considerable interest because of their magnitude, but they are of interest also because they occur with the very first stroke of the heart after occlusion. The immediacy of the response might make one wonder whether the response is mediated by some reflex mechanism. In the present investigation dogs with large femoral fistulas were studied with regard to alterations in blood pressure, pulse and cardiac output upon digital occlusion of the fistula. The same studies were made upon dogs with normal cardiac innervation, in dogs with sympathetically denervated hearts and, finally, in dogs with hearts deprived of both sympathetic and vagal innervation. It was a remarkable observation that blood pressure and cardiac output changes occurred in animals with denervated hearts just as in animals with normally innervated hearts. These studies may be of significance, not only in understanding the problem of the circulatory changes in arteriovenous fistulas, but also with regard to the response of the heart in general to stress and alterations of circulatory dynamics.

12. Experimental Attempts at the Surgical Relief of Aortic Stenosis.

Charles P. Bailey, M.D., Robert P. Glover, M.D.,

Thomas J. E. O'Neill, M.D. (by invitation) and

Hector P. Redondo Ramirez, M.D. (by invitation)

Philadelphia, Pa.

A study has been carried out on dogs in an effort to explore various methods designed to overcome the physiological derangements of aortic stenosis. This investigation has taken three forms:

(1) An appraisal of the technical difficulties of punch resection of portions of the aortic valve utilizing both the innominate artery and the left ventricle as approaches.

(2) An approach through the left ventricle and utilizing instruments similar to those devised by Dr. Brock in stenosis of the pulmonary valves.

(3) Efforts were directed toward by-passing the aortic valve in dogs by utilizing grafts of aorta from donor animals. These grafts included the donor aortic valve. In all instances the distal end of the graft was anastomosed to the descending aorta of the recipient dog just below the left subclavian artery, using an end-to-side technic. In half of the dogs the proximal end was introduced through the left auricular appendage and mitral valve and, second, in the chamber of the left ventricle. Polythene tubing was incorporated in such a way in this proximal segment so as to facilitate maintaining patency. In the remaining half of the dogs the proximal segment was introduced directly through the wall of the left ventricle.

A summary of these experiences is presented together with illustrative lantern slides.

13. The Experimental Creation and Closure of Auricular Septal Defects.

Henry Swan, M.D. and (by invitation) George Maresh, M.D.,

Marvin E. Johnson, M.D. and George Warner, M.D.

Denver, Colo.

The problem of creating experimentally in dogs a lasting auricular communication which simulates anatomically the clinical defect is discussed. A method employing excision of the major portion of the auricular septum under direct vision with the auricle open is described. Despite the wide excision there is a strong tendency for the defect to close spontaneously.

A method for the closure of these experimental defects, which does not interfere with blood flow at any time and which leaves exposed to the intra-auricular blood stream only endothelialized surfaces, is described. This is accomplished by inversion of the auricular appendages through the septal defect. Cardiac catheterization and autopsy studies reveal this to be an effective method of closure of such defects in the experimental animal.

14. A Physiological Evaluation of Vagus Section for Bronchial Asthma.

Karl P. Klassen, M.D., Douglas R. Morton, M.D.

(by invitation) and George M. Curtis, M.D.

Columbus, Ohio

Various surgical procedures have been performed on the extrinsic pulmonary nerves in patients with intractable asthma. Of these, unilateral cervical vagotomy, unilateral cervical sympathectomy, stellate ganglionectomy, bilateral cervical sympathectomy and bilateral resection of the posterior pulmonary plexus have been performed more frequently. Unfortunately the results from these various procedures have been more or less equivocal. This fact has stimulated our clinical study, in order to evaluate further the neurophysiology of the bronchi.

In a series of patients with bronchogenic carcinoma, found to be inoperable at exploratory thoracotomy, the homolateral vagus trunk was transected immediately below the recurrent laryngeal nerve. Postoperative studies revealed that:

(1) The cough reflex arising from the homolateral bronchial tree was abolished in all instances.

(2) In the majority of cases pain of bronchial origin was abolished on the homolateral side.

(3) No effect on the physiological respiratory change in bronchial caliber was noted, nor was any effect observed on bronchial motility.

(4) On bronchoscopic observation no subsequent changes were noted in the amount nor in the consistency of bronchial secretion; likewise, postbronchography roentgenograms revealed no impairment of lipiodol clearance of the tracheobronchial tree.

These studies were performed on individuals in whom bronchospasm was not a factor, and no evidence of postoperative paralytic dilatation of bronchi was noted. However, inasmuch as the majority of authorities consider the vagus nerve to be the main "bronchomotor" nerve, and since individuals with bronchial asthma exhibit a variable degree of bronchospasm, it was postulated that bilateral vagotomy just below the origin of the recurrent nerves might prove of some value.

Three cases of bilateral parasympathectomy of the bronchi for intractable asthma are presented. Postoperative studies reveal the bronchospasm to be persistent. This is confirmatory evidence of our previous work performed on patients with inoperable bronchogenic carcinoma, in that vagotomy or parasympathectomy of the bronchial tree does not influence the caliber or motility of the bronchi.

15. Therapeutic Status of Pulmonary Autonomic Nerve Surgery.

Osler A. Abbott, M.D. and (by invitation)

William A. Hopkins, M.D. and Paul H. Guilfoil, M.D.

Emory University, Ga.

This study consists of an evaluation of the results of various types of surgery of the autonomic nerves in patients with different pulmonary diseases. The authors present comparative series of patients with intractable bronchial asthma treated by (a) pulmonary plexectomy, (b) upper dorsal post-ganglionic sympathectomy and (c) either (a) or (b) plus segmental resection for "trigger" areas of chronic destructive infection. An attempt is made to determine the causes of failure in this therapeutic approach to bronchial asthma. The value of autonomic nerve surgery in conjunction with pulmonary resection in bronchiectasis is also considered, in view of comparable patients treated before and after the addition of autonomic nerve surgery to the operations for this disease. A discussion of experiences with surgery of the autonomic nerves in the surgical treatment of pulmonary emphysema is presented. Other lesions considered include (a) recurrent spontaneous pneumothorax, (b) recurrent pulmonary thrombosis, (c) palliative measures in bronchogenic carcinoma, (d) intractable bronchorrhoea.

An attempt has been made to evaluate the effect of these procedures by pre- and postoperative respiratory physiological studies. The prognostic value of such studies carried out, with and without various bronchial dilators, is discussed. It is felt, that from experience with over 150 cases of pulmonary autonomic nerve surgery, we are allowed to make certain preliminary conclusions: (1) that this can be a valuable adjunct to thoracic surgery but, (2) further clinical studies, with particular stress on objective pulmonary functional tests, are required.

16. The Surgical Treatment of Intractable Asthma.

Brian Blades, M.D., Edward J. Beattie, Jr., M.D. and

(by invitation) William S. Elias, M.D., Washington, D. C.

An analysis of thirty-seven cases of intractable asthma subjected to surgical intervention will be presented.

Follow-up reports and immediate and late mortality rates will be reviewed.

Various ramifications of the investigation, which may be more important than the original problem, will be presented. These include residual air studies, effects on electrocardiograms and pulmonary artery pressure readings.