These intrascrotal masses are usually managed by the pediatric urologist. Hydroceles and hernias are both due to incomplete obliteration of the processus vaginalis. The testis enters the inguinal canal posterolateral to and following the protruded sac of the peritoneum, usually reaching the base of the scrotum at the seventh to ninth month of intrauterine life.
Complete or incomplete failure of processus obliteration predisposes to development of a hernia or hydrocele in infancy and childhood. Irregular obliteration produces a variety of combinations of hydroceles, encysted hydroceles and/or hernias. The processus vaginalis is normally patent at birth and can still be identified in about 50% of one-year-old boys. A communicating hydrocele will increase in size with ambulation. On examination it has a cystic feel and transilluminates. It may be tender if it suddenly obstructs, but this is unusual.
Many infant hydroceles will resolve spontaneously, so repair is usually delayed until the child is 2 years of age or older should the swelling remain.
Peritoneal shunts may also cause hydroceles.
Repair is through a small transverse inguinal skin crease incision under an outpatient general anesthetic. The sac is dissected off the cord structures and tied off, and the wound is closed with an absorbable stitch. Rarely there may be a recurrence, especially if the distal end of the processus closes off after surgery with failure of the hydrocele to decompress.
An inguinal hernia is a patent processus vaginalis containing bowel, omentum or bladder. Inguinal hernias occur in 1% to 4% of boys and rarely in girls. 50% to 60% are on the right, 30% on the left and 10% to 20% bilateral. The frequency increases with prematurity and children with birth defects. Clinically, infants are fussy and irritable and a bulge will be noted lateral to the pubic tubercle. Hernias are not uncommonly associated with testicular maldescent. A major concern with hernias is possible incarceration or infarction of bowel.
Most incarcerated hernias can be reduced non-operatively so that emergency surgery is thwarted. Demerol sedation 2 mg per kilogram, ice packs, Trendelenburg positioning and manipulation are usually required to achieve reduction. Reduction may not be advisable if the bulge has been present for several hours or if there is associated fever, vomiting and/or inflammation.
High ligation of the sac which is dissected from the posterolateral cord structures can be achieved, often without opening the external ring. Recurrence is unusual, as is testicular ascent, after the surgery.
Routine bilateral exploration is controversial. After unilateral infant hernia repair, 10% can develop a contralateral hernia by the age of 6 years. A small but appreciable incidence of testicular atrophy after repair may occur.