stretching of the hepatic vessels and multiple area of neovascularity (N ) Note marked stretching and displacement of the inferior vena cava (I ) with patent portal vein (P ) A, aorta ABDOMINAL WALL DEFECTS Inguinal Hernias and Hydroceles Indirect inguinal hernia is the most common congenital anomaly that is found in children It is approximately 10 times more common in males than in females There is a strong familial incidence Clinical Manifestations The child with a hernia may present in different ways The presentation is determined by the extent of obliteration of the processus vaginalis during development A child may have a completely open hernia sac, which extends from the internal ring to the scrotum, or a segmental obliteration producing a sac that is narrow at its proximal end, creating a hydrocele of either the tunica vaginalis or the spermatic cord The narrowing of the processus allows the abdominal fluid to seep into the distal portion of the sac It then becomes entrapped and produces what is clinically recognized as a hydrocele It is often difficult for this fluid to egress through the narrow patent processus vaginalis back into the abdominal cavity At the time of the embryologic closure of the processus vaginalis, many fetuses will have some fluid trapped around the testicle in the tunica vaginalis This is called a physiologic hydrocele, which is a normal newborn finding In such cases, the fluid is gradually absorbed in the first 12 months of life If, however, an infant or child develops a hydrocele along the cord in the tunica vaginalis sometime after birth, it must be assumed the processus vaginalis is still patent and in communication with the peritoneal cavity This patent processus vaginalis represents a hernia sac Surgical closure of the sac and drainage of the hydrocele are then indicated on an elective basis Many infants and children manifest the classical bulge in the inguinal canal that occurs during straining or crying This is caused by a loop of intestine distending into the hernia sac (or may represent the ovary in a female) Usually, the hernia sac contents reduce into the abdominal cavity when the straining ceases If the prolapsing loop of intestine becomes entrapped in the hernia sac, an incarceration has occurred This is a true emergency that could eventually lead to intestinal obstruction and possibly strangulation of the bowel For easily reduced