When the intestinal end alone persists a protrusion or sacculation will remain to mark its site.
The duct may become obliterated and yet fail to disappear, thus leaving a fibrous cord which represents the original omphalomesenteric structures and vessels, which will be probably mistaken for an inflammatory band and may serve as a later cause of acute obstruction. If such bands lead to the umbilical region their identity may be easily established.
The presence of Meckel’s diverticulum may cause serious abdominal mischief. It may become involved in a localized process exactly as the appendix often does, which may then be referred to as a diverticulitis, where ulceration and perforation may occur. It may constitute the whole or a portion of the contents of a hernial sac. I have twice found it in inguinal hernia, once in umbilical hernia, and by others it has been reported in all the ordinary hernial locations. Porter has collected from literature 184 cases in which its presence caused serious abdominal crises. The condition itself is probably present in at least 1 per cent. of mankind, and is stated by Halsted to be the cause of intestinal obstruction in 6 per cent. of cases. In the 184 collected cases above mentioned it caused obstruction in 101. Out of 21 cases of the above collection it was not only found in the hernial sac, but in all but 1 was shown to be the actual cause of the trouble. In 5 of these cases the diverticulum was open at the umbilicus. In such a case if the opening be large the gut wall might prolapse and thus form a hernia.
Diverticulitis has been repeatedly mistaken for appendicitis, its symptomatology not being distinctive. Exact diagnosis is seldom possible before operation.
On general principles, considering their possible dangers, it would be well to remove all diverticula which are found in the course of ordinary abdominal operations, whether they appear to be causing trouble at the time or not.
While the average length of Meckel’s diverticulum is three inches it may exist as a mere nipple-like projection, or it may be a free tube attaining a length of several inches. Its attached end is usually larger than its distal portion and its diameter usually less than that of the gut from which it arises. It may be provided with a scanty mesentery or may hang independently. While ordinarily its distal end is free it may nevertheless be continued as a solid cord attached, as above mentioned, to the umbilicus. This cord frequently contracts secondary adhesions, and it is under these conditions that it most often constricts the bowel by forming a loop within which the intestine becomes entangled. Free diverticula of sufficient length are sometimes found tied in a genuine knot in a manner which is absolutely inexplicable. There are numerous ways by which such a diverticulum may produce strangulation of the normal bowel; thus, by formation of a ring in which its own free end projects, in which is later entangled a bowel loop, or by surrounding the pedicle of an intestinal loop as might a noose. Again bowel is sometimes tightly drawn over such a diverticular band, just as a shawl may be thrown over the arm, obstruction following in the displaced bowel. When much contraction is brought to bear the gut may be so acutely bent as to become occluded. Finally the bowel at the point of origin of the diverticulum may undergo gross structural changes, the result of long-continued traction, which may lead to cicatricial narrowing. More indirectly diverticula seem in some unknown way to predispose to intussusception at their point of origin, or they have been found inflated and hanging from the intestine after obstructing it ([Fig. 559]).
Fig. 559
Meckel’s diverticulum still attached at the umbilicus and producing obstruction. (Lejars.)