Definitive identification of a patent processus vaginalis by intraoperative injection of methylene blue into the hydrocoele sac

Abstract 

Objective

Seven percent of patent processus vaginali (PPVs) are obliterated at exploration. This potentially increases the risk of cord injury with a subsequent increased risk of testicular atrophy or reduced fertility. We report a modification of a technique to improve identification of the PPV and thus potentially minimise the risk to the cord.

Methods

Fifteen consecutive boys were operated on via a standard inguinal approach. The testicle was delivered and 0.2–0.5ml of a 50% methylene blue/normal saline solution was injected into the hydrocoele sac. A PPV is identified as a blue line.

Results

Methylene blue injection identified all PPV. In a case with an encrusted hydrocoele of the cord and a hydrocoele this anatomy was clearly delineated. Dissection in a recurrent case was better facilitated. No testicular atrophy was recorded and there were no significant complications.

Conclusions

Intraoperative injection of a methylene blue solution into a hydrocoele sac will aid identification of a difficult PPV, thus minimising the risk of cord damage. This is especially helpful in cases of recurrent hydrocoele.

Keywords: Methylene blue, Patent processus vaginalis, Hydrocoele, Pediatric