Ultrasonographic diagnosis for potential contralateral inguinal hernia in children.

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

Methods: 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.

Results: 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.

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