Introduction

• Infants and children who have a unilateral inguinal hernia have a high incidence of "bilateral hernias" in the form of a contralateral patent processus vaginalis. This incidence approaches 60-75% in the first two months of life, declining gradually to about 40% at age 2, after which the incidence levels off. Half of these children, or 20% of the total, will eventually develop a clinically evident inguinal hernia on the contralateral side.

• All agree that surgery is required for treatment of an inguinal hernia.

• Many surgeons believe that, since an open peritoneal sac is both common and difficult to diagnose by preoperative physical examination, a blind exploration of the so-called silent side is justified since the patient will be spared the cost and risk of a second surgical and anesthetic procedure.

• The proponents of performing only unilateral surgery claim that, with bilateral surgery, many unnecessary operations (60-85%) are performed, anesthesia time is extended, and there is the possibility of damage to the normal structures of the groin (cutting or crushing the vas deferens, testicular atrophy in 1-2%).
   
• The foremost use of herniography is NOT in the detection of inguinal hernias already known to be present, BUT in the detection of clinically inapparent or elusive hernias and communicating hydroceles (potential hernia sacs.).

• Herniography is relatively safe and easy to perform. The test can accurately identify the 40% of children with an open processus vaginalis, thereby sparing at least 60% of children a needless surgical procedure. Herniography has an accuracy of 95% as compared with a 53% accuracy rate by physical examination.