APPENDICITIS, the name applied to an infectious disease of the vermiform appendix, a small organ occupying the lower right side of the abdominal cavity. The first authentic rec ord of the distinct localization of a lesion in the appendix was made by Saracenus in a letter 28 Aug. 1642. A number of observers described the disease in later years, but it is to the honor and credit of American medicine that Reginald Fitz of Boston wrote his epoch-making memoir in 1886, On Perforative Inflammation of the Vermiform Appendix.' Two years later Fitz advanced the sound theory that the diseases variously described as typhlitis, peri-typhlitis, para-typhlitis, appendicular peritonitis, and peri typhlitic abscess were all varieties of one and the same affection, namely, appendicitis. Rapid strides have been made during the last decade in the study of the disease, and mainly through the exertions of American surgeons the treat ment of appendicitis has been placed upon a sound and rational basis. In the embryologic development of the human intestinal tract there is at first a straight tube, divided into the fore gut, midgut and hindgut, each of which gives rise to different structures. From the midgut a diverticulum or pouch appears which marks the dividing line between the large and small intestine. This pouch becomes larger and is called the cecum, but its terminal portion does not keep pace with the growth of the base and remains as a small projection depending from the cecum. This is the appendix vermiformis; it has no function and from its liability to disease is merely a constant source of menace.
During early intrauterine life the appendix lies near the umbilicus (navel), but at about the sixth month descends into the right iliac fossa. If two lines are drawn at right angles to each other, intersecting at the umbilicus, the abdomen will be divided into four quadrants. The lower right quadrant will include the right iliac fossa and in the majority of cases the appendix. The base of this organ will usually be found at a point two inches from the umbilicus on a line drawn from the latter to the anterior superior spine of the iliac bone and known as McBur ney's point.
The appendix is held in place by a fold of peritoneum called the meso-appendix through which a single artery runs to supply the needed nutrition. The meso-appendix is derived from the lower layer of the mesentery, the fold of peritoneum which suspends the small intestine. In women there is usually also another blood vessel which comes up to the appendix from the ovary. The end of the appendix is free and may point in any direction. This fact explains the great diversity of the symptoms often noted in appendicitis.
Bearing in mind, then, that the appendix is without a function, hangs in a dependent posi tion from a portion of bowel always containing irritating material, and has a very poor blood supply, it can readily be understood why this organ is so often attacked by disease. It hangs
in a cavity lined by peritoneum, a delicate mem brane covering the inner surface of the abdomen and the exterior of the intestines, which easily absorbs poisons and transmits them to the whole body. Inflammation of this membrane is known as peritonitis, a very fatal disease and often caused by appendicitis. Many deaths supposed to be due to peritonitis pure and simple are really caused by appendicitis. The intestines at all times are loaded with germs which under favorable conditions may be converted into deadly little organisms. These microbes at tack the inner coat of the appendix, destroy it with the formation of pus, and may ulcerate through all the walls of the appendix causing an abscess, with peritonitis. But the recurrence of such a sequence of events requires certain other contributing factors. The old idea that foreign bodies, such as grape-seeds, are the cause of the disease, has been disproved. While foreign bodies are frequently found in the ap pendix, in rare instances only are they seeds, etc., but are almost always found to consist of masses of fecal material which having entered the appendix while soft, become dry and hard, and form a fecal concretion (fecal calculus). By exerting pressure on the wall of the appendix these hard bodies may aid in the production of the disease. In rare instances pins have found their way into the lumen of the appendix and induced ap pendicitis. It is interesting in this connection to note that worms are frequently discovered in the appendix. The Oxyuris vermicularis, or seatworm, has been found in large numbers completely filling the appendix, and the Ascaris lumbricoides, or roundworm, has sometimes oc cupied this organ. In studying the etiology of appendicitis we find that young persons are more frequently attacked than the older ones, the disease occurring less commonly after the 50th year of life. It is fortunate that such is the case, because older people, as a rule, do not stand operations so well as those in early adult life. Their resistance to shock is less, and their greater liability to kidney breakdown and to pneumonia would close their prognosis in many instances. The greater susceptibility of young adults to appendicitis is due to the more fre quent disturbances of their gastro-intestinal tracts from dietary indiscretions, and, secondly, to the tendency to inflammation of the adenoid (glandular) tissues throughout the body during adolescence. Analogy is found in the pre dominance of lesions of the tonsils and of the glands in the neck and mesentery dur ing the period of development. In children appendicitis is characterized by the intensity of the lesion as well as by the remarkable re cuperative power which children have.