Safety And Efficacy Of Intratesticular Injection Of Vital Dyes For Lymphatic Preservation During Varicocelectomy

Purpose: The most common complications of varicocelectomy include failure and hydrocele formation. Various surgical approaches have been used to minimize complications and guarantee durable results. The use of vital dyes to visualize and preserve testicular lymphatics intraoperatively has been proposed to reduce the incidence of hydrocele formation. We investigated the safety of intratesticular injection of various vital dyes and their efficacy in allowing visualization of lymphatics for varicocelectomy.Materials and Methods: Using general anesthesia, 22 adolescent rats underwent bilateral transscrotal intratesticular injection of methylene blue, isosulfan blue, trypan blue or normal saline. All rats with intratesticular injection of a vital dye underwent immediate exploration of the spermatic cord to observe for visualization of lymphatic vessels. At 3 months all rats were euthanized, and orchiectomy was performed for histological examination.Results: Spermatic cord lymphatic vessels were variably visualized depending on concentration and volume of the vital dye used. Histological examination of the testicles at 3 months after injection revealed areas with necrosis of seminiferous tubules, thickened tubular basement membranes, interstitial fibrosis and hyalinization, and striking intratubular dystrophic calcification. These pathological changes were present to varying degrees in all groups.Conclusions: Although spermatic cord lymphatic channels were successfully visualized to varying degrees, intratesticular injection of vital dyes (and even normal saline) produced pathological changes in all groups, despite variation of concentration, volume and type of vital dye. Intratesticular injection of vital dyes for the visualization of lymphatics during varicocelectomy should be abandoned. Paratesticular injection of vital dyes should be used with caution.