4. Persistence of the Dudes Omphalomescnterieus (Vilelline Duct).. —Physiologically the oniphalo-enteric duct which leads from the yolk- sac to the intestinal tube, is obliterated by the end of the second foetal month. In case obliteration does not occur, various anomalies can arise, the most important of which, for the newborn, is the open .11eckel's diverticulum. In such cases the ductus oinphalo-entericus is patent in its abdominal portion and sometimes for a short distance in the cord. After the cord separates, the wound does not heal completely and there' remains a narrow, constantly secreting fistula. In marked cases the fistula is wide open, persistently discharging a cloudy fluid, easily iden tified as intestinal contents. In other cases, fluid may be obtained by passing a small soft catheter; examination, chemical and microscopic, of this fluid shows it to be intestinal contents (fat globules, acidity, odor. negative murexide test).
In other cases the umbilical wound heals over, but a short time later some secretion appears. In these cases epithelial adhesions close the peripheral end of the duct and later gradually loosen. In other cases a tumor about the size of a hazel-nut with velvety surface is found in the navel region either immediately after the separation of the cord or else a few days or weeks later; this shows a prolapse of the wall of the fistula and in rare cases a prolapse of intestinal coils through the fistula can occur. Cases of umbilical in which the walls show a structure similar to the gastric mucosa are totally obscure.
The diagnosis of an open Aleckel's diverticulum is as a rule not diffi cult. It is important not to confuse the small tumor resulting from pro lapse of the mucosa of the diverticulum. with a sarcomphalus or an
enteroteratoma. It can be differentiated from patent urachus fistula). by a chemical and microscopic examination of the secretion.
The prognosis is very good. Rational therapy demands the excision of the whole diverticulum by laparotomy. However, conservative treatment by cauterizing the fistula with silver nitrate or the actual cautery, sometimes effects the closure of the fistula.
5. Crack us Fistukr.—The stalk of the allantois, which extends to the summit of the bladder, becomes obliterated in its extra-abdominal portion during the second fatal month. Its abdominal portion per sists as the urachus and its lumen is either totally or partially obliterated.
In exceptional instances when there is obstruction to the outflow of urine through the urethra, a condition occurring more often in boys than in girls, the urachus remains patent throughout, forming a fist u lous tract which terminates at the umbilicus. After the separation of the cord one finds, at the umbilicus, a fistula from which urine is passed, either upon pressure or during micturition.
In some cases, just as with a patent lleckel's diverticulum, a small, tender, red tumor is found in the umbilical region, varying in size and bearing the fistulous opening on its summit. The tumor owes its origin to a prolapse of the mucosa lining the urachus. Probing and the chemi cal examination of the evacuated fluid for uric acid, as well as its micro scopic examination, confirm the diagnosis.
The treatment consists in the cauterization of the fistulous open ing. Should this not avail, suture of the walls of the fistula, after freshening their surface, is recommended.