E X P E R I M E N T A L S T U D I E S 0 N A C U T E G A S T R I C D I L A T A T I 0 N by R. Wekselman, B. Sc., M. D. Research Assistant in the Department of Experimental Surgery, Demonstrator in the Department of Anatomy, McGill University, Montreal, Canada. A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the Degree of Master of Science. August, 1961. McGill University. "When thus you pause in serious dubitation You must then think of GASTRIO DILATATION • 11 Sir Zachary Oope. i PREFACE The author of this thesis enlisted in the Faculty of Graduate Studies at McGill University in July 1960. Dr. Stanley c. Skoryna, Research Director of the Department of Experimental Surgery, suggested that I undertake the study of "Acute Gastric Dilatation" on which some of the preliminary work has been carried out in the department. This happened to coincide with my personal interest derived from having previous training in Surgery. I also happened to read a press report of the case of one, Sharry Rubin (Time, December 1958), a 11 neurotic 11 New York girl who developed acute gastric dilatation following the ingestion of an abnormally large meal and died. The review of literature revealed that numer­ ous controversies exist on this subject, sorne of them based on older ill-founded views which do not stand the scrutiny of modern methods of investigation. It appeared also, that only a small amount of experimental work has been carried out on the subject recently, and that a reevaluation of the problem is needed. One particular aspect is worth mentioning and that is, that ii acute gastric dilatation is a frequent condition in cattle and sheep, and that sorne elues as to its etiology may be derived from correlated studies. During the year of investigation at McGill University, I consider myself fortunate to have had advice from many members of the Departments of Surgery and the Basic Sciences. It has indeed provided me with an opportunity to learn not only the method, but also the significance of medical research and to appreciate its importance in clinical practice. I would like to thank Dr. D. R. Webster, Professor of Surgery at McGill University and Surgeon­ in-Chief at the Royal Victoria Hospital, for making the necessary arrangements and providing the facili­ ties on the study of gastric dilatation. The research project was under the supervision of Dr. s. C. okoryna, the Director of Research of the Department and Assistant Professor of Surgery. He originated this study and gave excellent guidance throughout the year. I'·1any of his thoughts have been used in expanding the thesis. Dr. C. A. Macintosh, Professor of Physiology, contributed several very constructive ideas on the physiology of the stomach, and suggested modifications iii of the recording apparatus. Dr. li. G. B. Gi~bert, Chairman of the Department of Anaesthesia at McGill University has been very helpful in attending seminars on the subject and making several very useful and pertinent suggestions. Dr. D. s. Kahn, Assistant Professer of Pathology at McGill University, has also been very kind in reviewing the pathology of sorne of the specimens that were used in the study. Dr. D. G. Dale (D. V. M.), Assistant Professer of Animal Science at Macdonald College,has been very kind in making avail­ able the departmental and his personal library for the review of literature on gastric dilatation in animals. Dr. I Kwilecki, Assistant Professer of the Department of Pharmacology at the University of Ottawa, was very useful for her suggestions on the use of various phar­ macological compounds used in the investigation. Dr • .D. A. Murphy (D. V. J.Vl.), presentl.y on the House ~taff of the Montreal General Hospital, has spent con­ siderable time with the author in reviewing the data on the development of gastric dilatation in cattle. Dr. P. Secoly, Medical Electronist of the Department of Physiology, suggested the modification for the channel recording apparatus. Mr. P. L. Rojowski (M.Sc.) iv very skilfully constructed the necessary recording apparatus used in the study. Dr. P. Bryden, of the Department of Psychology, very kindly assisted in the statistical analysis of the resulta. I would like to thank Miss u. Murer who was very efficient in the management of the secretarial work and the correspondance on the subject, and Miss A. Watkins who cheerfully gave her time in pre­ paring the various biochemical and pharmacological solutions used in the experimenta. Mrs. L. Tripanova prepared excellent microscopie elides that were used in part of the study. I would also like to thank Mr. M. Farrel, Mr. J. Byers and Mr. s. Podymov for their kind assis­ tance in the experimental operations and in the care of the animale. It was a pleasure to have spent the year with the other Research Assistants in the Department who added sorne ideas and provided encouragement dur- ing the experimental year. They include: Drs. R. Beaudry, A. Becerra, R. Chari, A. Dukay, G. Elias, A. Legare, D. McSweeney, G. Prohaska and E. Wright. My gratitude goes to the University of Alberta, v and its professors of the Faculty of Medicine under whom I studied as well as to the Misericordia Hospital In Edmonton and its Staff Men, under whom I interned, as their guidance and the training they provided was valuable for the preparation of this year of research. At last but not least, to my wonderful wife, Edna, without whose constant encouragement and under­ standing, it would not have been possible for me to reach this stage of my career. I am also very grate­ ful to her in having the patience in proof-reading and typing this thesis. vi TABLE OF CONTENTS Page PREFACE • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • i TABLE OF CONTENTS ••••••••••••••••••••••••••••• vi LIST OF TABLES AND ILLUSTRATIONS •••••••••••••• ix OHAPTER I: INTRODUCTION ••••••••••••••••••••• 1 OHAPTER II: ETIOLOGIOAL FACTORS IN GASTRIO DILATATION IN MAN •••••••••••••••• 5 A. Anatomical Factors •••••••••••••••••••• 5 B, Physiological Factors ••••••••••••••••• 10 o. Idiopathie Gastric Dilatation ••••••••• 24 OHAPTER III: GASTRIO DILATATION IN ANIMALS •••• 26 A. Etiology of Bloat ••••••••••••••••••••• 27 B. Mechanism of Bloat •••••••••••••••••••• 29 O. Course of Bloat ••••••••••••••••••••••• 29 D. Therapy of Bloat •••••••••••••••••••••• 35 E. Prevention of Bloat ••••••••••••••••••• 36 OHAPTER IV: OLINICAL COURSE OF GASTRIC 1 DILATATION ••••••••••••••••••••••• 37 A. Symptoms and Signs of Acute Gastric Dilatation •••••••••••••••••••••••••••• 38 B. Laboratory Findings in Acute Gastric Dilatation •••••••••••••••••••••••••••• 39 vii Page c. Treatment of Acute Gastric Dilatation •• 43 D. Prophylaxie of Gastric Dilatation •••••• 46 E. Prognosis of Acute Gastric Dilatation •• 47 CHAPTER V: SPONTANEOUS GASTRIC RUPTURE •••••• 49 Note on Traumatic Rupture of the Stomacn •• 51 CHAPTER VI: PATHOLOGICAL FINDINGS IN ACUTE GASTRIC DILA~TION AND SPONTANEOUS RUPTURE OF THE STQrtlACH • • • • • • • • • • • 53 CHAPTEh VII: MATERIALS AND ~ŒTHODS •••••••••••• 6L A. General Comments on the Apparatus Used •• 62 ~. Apparatus for measuring the effects of acetylcholine on the contractility of the gastric wall ••••••••••••••••• 62 ~. Apparatus for measuring the intralu­ minal gastric pressure by distension with knwon voluntes of fluid ••••••••• 66 B. General Comments on the Methods Used ••• 70 1. Hethod of study of the contractility of strips of gastric wall on the various experimental conditions ••••• 70 2. Method of study of the intraluminal gastric pressures by distending the stomach with fluid •••••••••••••••••• 71 C. Genera~ Commente on the Preparation of Various Groups of Experimental Animals.. 73 1. ~tudies on the gastric tonus under various experimental conditions ••••• 73 2. :studies on the influence of pantothenic acid and magnesium on the tonus of the gastric wall •••••••••••••••••••••••• 76 viii Page CHA~T~ VIII: EFFECTS OF C~TYLCHO~INE UPON TID.; CON :J!RA ü GAo:J!RIC WA • • • • • • • • • • • • • • • • • EFFECTS OF STENSIO.N BY M~oUlŒ!J VO rŒS OF FLUID UPON THE GA' RIC WAL~ •••••••• 92 A. Discussion of the Me hod of Conversion of Pressure to Radi and Longitudinal Force •••••••••••••••••••••••••••••••• 92 B. Effects of Distensio on the Wall of the whole otomach 94 1. ~xperiments on r s weighing 220 to 250 grams • • • • • • • • • • • • • • • • • • • • • • • • • 94 2. ~xperiments on r ts weighing 70 to 80 grams •••••••••••••••••••••••••• L07 0. Effect of Distensio on the Wall of the Ruminectomized o omach ••••••••••• ~18 CHA~T~R X: ONCLUSIONo •••••• .i2'( BIBLIOGRAPHY • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 129 ix LIST OF TABLES AND ILLUSTRATIONS Page FIGURE I • Acquired duodenal ileus •••••••• 6 FIGURE II • Gastric dilatation aggravated by nasal oxygen ••••••••••••••••••• 21 FIGURE III • Cow suffering from bloat ••••••• 30 FIGURE IV • Escape of foamy ingesta from incised rumen •••••••••••••••••• 32 FIGURE V • Air-fluid levels in gastric dilatation ••••••••••••••••••••• 41 FIGURE VI : Barium-outlined dilated stomach. 42 FIGURE VII • Autopsy specimen of gastric dilatation ••••••••••••••••••••• 54 FIGURE VIII Gross specimen of dilated stomach •••••••••••••••••••••••• 55 FIGURE IX • Gross specimen of dilated and ruptured stomach ••••••••••• 56 FIGURE X • Perforation site of dilated stomach •••••••••••••••••••••••• 57 FIGURE XI : Perforation site of dilated stomach •••••••••••••••••••••••• 58 FIGURE XII : Apparatus for studying effects of acetylcholine •••••••••••••••