A newborn has a midline defect in the anterior abdominal wall. The parents ask what, if anything, should be done, Spontaneous closure of which of the following congenital abnormalities of the abdominal wall generally occurs by the age of 4?
|C||Patent omphalomesenteric duct|
a. The umbilicus is formed by the umbilical ring of the linea alba.
b. Intra-abdominally, the round ligament (ligamentum teres) and the paraumbilical veins join into the umbilicus superiorly, and the median umbilical ligament (obliterated urachus) enters inferiorly.
c. Umbilical hernias in infants are congenital and are quite common. They close spontaneously in most cases by the age of 2 years. Those that persist after the age of 5 years are frequently repaired surgically, although complications related to these hernias in children are unusual.
d. These hernias are more common in women and in patients with conditions that result in increased intra-abdominal pressure, such as pregnancy, obesity, ascites, or abdominal distention.
e. Umbilical hernia is more common among individuals who have only a single midline aponeurotic decussation compared with the normal decussation of fibers from all three lateral abdominal muscles. Strangulation is unusual in most patients; however, strangula-tion or rupture can occur in chronic ascitic conditions.
f. Small asymptomatic umbilical hernias barely detectable on examination need not be repaired.
g. Adults who have symptoms, a large hernia, incarceration, thinning of the overlying skin, or uncontrollable ascites should have hernia repair.
i. Classically, repair was done using the vest-over-pants repair proposed by Mayo, which employs imbrication of superior and inferior fascial edges.
j. Instead, small defects are closed primarily after separation of the sac from the overlying umbilicus and the surrounding fascia.
k. Defects greater than 3 cm are closed using prosthetic mesh.
l. There are multiple techniques to place this mesh and no prospective data have conclusively found clear advantages of one technique over another.
m. Options for mesh implantation include bridging the defect, placing a preperitoneal underlay of mesh reinforced with suture repair, or placing it laparoscopically.
n. The laparoscopic technique requires general anesthesia and probably is reserved for large defects or recurrent umbilical hernias.