According to the origin and cause of intussusception, one distin guishes acute, subacute and chronic forms, of which the last is only observed in later childhood, while the acute and SUbaCtIte types occur particularly during infancy.
On anatomical examination of intussusception, one finds gen erally, above the tumor, a dilated portion of intestine, and, below the mass. contracted bowel (see Fig. 25 and Fig. p on Plate 1St If it begins acutely, symptoms of incarceration appears for the marked contraction in the region of the neck of the intussusception and the traction of the mesentery lead to cedematous infiltration of the intestinal walls with stasis and bloody exudation. The longer the strangulation lasts the more severe becomes the inflammatory swell ing, to which is added pressure necrosis and gangrene, which takes place for the most. part in the inner cylinder, particularly about the head and neck of the intussusception. Moreover, adhesions between single serous and mucous surfaces are formed, and finally, by the continuation of the strangulation, the delicate tissue is torn in one or more places, so that one can see, as through a sieve, the intussuscep tion, which, otherwise, is not visible from without. It is evident under these conditions that the neighboring portions of the intestine, espe cially the part lying above the obstruction, and the peritoneum will be involved in the spread of inflammation. The gangrene of both inner cylinders can completely destroy them, and in this way a kind of spontaneous healing may take place, since the involved portion can be discharged per vias naturales as a decomposed, dark, foul-smelling loop of tissue. In the meantime, sufficiently firm adhesions between the outer cylinders and the neigh boring parts may be formed, so that the lumen is again established, although, since in any case, a deeply ulcerated mucosa is present at the seat of the previous invagi nation, cicatricial stenoses are rarely absent. Intestinal intussus ceptions extending deeply into the rectum, and such as appear par tially at the anus, lead to more extensive dilatation of the rectum and complete relaxation of t he sphincters. The longer the invagi nation exists, the less pronounced become the symptoms of reaction in its neighborhood. These, in chronic intussusception of the sniall intestine, can be limited to mode rate congestion. On still longer
duration, and the intervention of symptonis of incarceration, all the changes described above may de velop, and the intussusception be comes irreducible. Jalaguier compares the proces.s alluded to with chronic and, at first, easily- reduced hernias, which become suddenly- incarcerated.
Ray has observed primary rupture of the intestinal wall in a case of intussusception arising acutely, as a result of the strong pressure with which the intussusception \vas brought about.
The proper recognition of the condition is of great importance since the chance of cure becomes worse the longer the duration of the intussusception. The symptoms are for the most part so elear-cut that the diagnosis offers no unusual difficulties. One must here separate the acute from the chronic forms because these differ markedly from each other in their clinical manifestations.
The acute invagination, as its name implies, begins suddenly in the midst of perfect health, indeed there are observations where children became ill during sleep; or, moderate diarrhra, painful defecation and similar symptoms follow an injury. It begins for the most part with pain, which in younger children loads to restlessness and loud out cries. The legs are drawn up against the abdomen and nourishment is refused. Older children, who can localize their pain, speak often of a definite place, whieh generally corresponds to the point of invagination. (A boy, about two and one-half years of age, once said to me that a flea was biting him on the right side of the abdomen.) One often observes, moreover. a point of particular sensitiveness from which pain radiates in different directions (toward the navel, the bladder, the genitalia, etc). The pains and the reaction phenomena vary- according to the situation of the invagination. In intussusception of the large intestine they are very severe, uninterrupted, and followed by the quick collapse of the patient, since in this form the symptoms of incarceration set in quickly and increase. In other types they have a more paroxys mal character which is apparently associated with strong peristaltic movements. During the attacks of pain the abdominal muscles are tense and cramped, but after the pain has subsided the abdomen again becomes soft and is scarcely sensitive to pressure.