Methylene blue dye for identification of processus vaginalis during hydrocele repair: experience in a teaching hospital.

BACKGROUND: To investigate the use of methylene blue in perioperative identification of the patent processus vaginalis in a group of boys presenting with congenital or recurrent hydrocele where surgery was performed by junior surgeons in training. METHODS: We retrospectively reviewed the notes of 22 boys with hydrocele, of which two recurrences, who were operated on via a standard inguinal approach, by trainees. Methylene blue 0.3-0.5 ml was injected into the hydrocele fluid through the scrotal wall. A processus vaginalis was identified as a blue line. RESULTS: Methylene blue injection clearly identified a patent processus vaginalis in 91% of patients. In 9% (2 cases), of which one recurrence, methylene blue injection demonstrated a hydrocele with an obliterated processus vaginalis. There were no intraoperative complications. No testicular atrophy was recorded. CONCLUSIONS: Injection of methylene blue into the hydrocele sac may be considered a useful aid for a clearer identification of a difficult patent processus vaginalis. In the present series, there were no complications, and thus we believe that this technique might be suitable and especially helpful, in cases of recurrent hydrocele, and for junior surgeons in training.