Ultrasonographic diagnosis for potential contralateral inguinal hernia in children

The authors describe the diagnostic approach and the reliability of the diagnosis using their ultrasonographic classification for potential contralateral inguinal hernia in children.

In children presenting with unilateral inguinal hernia, the contralateral processus vaginalis in the inguinal canal was examined preoperatively by ultrasonography with a 10-MHz transducer. The findings, with increment and decrement of the intraabdominal pressure, were categorized into 6 types as follows: type I, the intraabdominal organ is observed in the inguinal canal; type II, the patent processus vaginalis (PPV) is seen cystlike at the internal ring of the inguinal canal; type III, the PPV is widened with abdominal pressure increment (the length of the PPV is longer than 20 mm); type IV, the PPV contains moving fluid without PPV widening; type V, the PPV is widened with abdominal pressure increment (the length is shorter than 20 mm); type VI, others. Types I through IV were regarded as potential candidates for inguinal hernia. The diagnostic performance of the clinical examination, with or without the assistance of ultrasonography was analyzed retrospectively.

The development rates of contralateral inguinal hernia following unilateral herniorrhaphy, before and after application of ultrasonographic diagnosis, were 10.2% (28 of 274 cases) and 1.5% (4 of 271 cases), respectively. The difference was statistically significant according to Fisher's Exact probability test.

Contralateral herniorrhaphy should be performed on inguinal hernia candidates when ultrasonography shows types I through IV.