Introduction: The issue of how to best detect an occult contralateral patent processus vaginalis (PPV) in a child who presents with a unilateral inguinal hernia has been debated for over 50 years. The ideal diagnostic tool would eliminate unnecessary contralateral exploration. The "silk glove sign" (SGS) or palpating the processus vaginalis over the pubic tubercle is the simplest preoperative diagnostic test for diagnosing contralateral PPV.
Materials and methods: In an attempt to determine whether it is possible with the SGS to evaluate the contralateral inguinal region to ascertain if a contralateral PPV is present, we prospectively reviewed our own experience at a single institution within a 5-year period. Between January 2001 and December 2005, 1,040 pediatric patients with inguinal hernias were treated by one surgeon at Chang Gung Children's Hospital. Of these, with the exception of 120 patients with clinical bilateral inguinal hernia, 920 patients (746 boys and 174 girls) with unilateral inguinal hernia underwent examination. A total of 180 (19.8%), of whom 154 were boys and 26 were girls, were SGS positive and underwent bilateral surgery.
Results: A PPV or true hernia sac was found in 164 (91.1%). The sensitivity of diagnosis by SGS was 93.1%. In the remaining 740 SGS-negative patients, a metachronous hernia developed in 20. The specificity of diagnosis by SGS was 97.3%. The SGS could detect a contralateral hernia in patients regardless of age, but the accuracy of detection in girls was lower than in boys.
Conclusion: SGS is a simple, noninvasive method of preoperative evaluation of the groins. Accuracy through repeated and careful examination is about 91%. Our policy of contralateral exploration based on the SGS has been reliable in minimizing unnecessary surgical exploration.