Laparoscopic varicocelectomy: Does intraoperative lymphography with vital dye influence the outcome?

Vital dyes lymphography during laparoscopic varicocelectomy (LV) has been suggested to allow for lymphatic mapping thereby allowing for lymphatic sparing (LS) and subsequent reduction of hydrocele formation. Intratesticular injection of the dye seems to achieve the best lymphatic visualization, however, the potential toxicity of some agents, is a cause of concern for the risk of testicular pathological changes. We report our experience with LV, to test the hypothesis that Intraoperative lymphography with methylene blue (BL), is safe and reduces the rate of post-operative hydrocelectomy. Secondary aim was to evaluate the effect of intratesticular injection of the dye.

Retrospective review of all consecutive patients undergoing LV < 18 years of age, between 2018 and 2022, and with at least 12-month follow-up. We compared hydrocele rate after LS-LV vs. non-LS-LV and between patients undergoing LS with vs. without BL and according to injection site. Post-operative ultrasounds were reviewed to rule out testicular anomalies in patients undergoing BL. Reoperations for varicocele were also noted.

116 patients undergoing LV at a median (range) age of 14 (10-17) years were included. Post-operative hydrocelectomy rate was significantly more common (p = 0.033) in patients undergoing non-LS (3/38, 8 %) vs. LS (0/78) LV. No hydrocelectomy was performed in patients undergoing LS-LV with (0/47) or without (0/31) BL. Vital dye injection site was intra-testicular in 21/47 (45 %) cases. Avascular intra-testicular lesions were identified in 4 (19 %) patients and persisted after a median (range) follow-up time of 21 (14-28) months. Two varicoceles were reoperated for recurrence, one in each group.

Vital dyes lymphography improves lymphatics visualization during LV. Although, in present study, overall hydrocele rate was not significantly different in patients undergoing LS vs. non-LS procedures, hydrocelectomy was required only after non-LS procedures. In keeping with other 2 recent studies, avascular intratesticular lesions were observed in one fifth of cases undergoing Intratesticular dye injection. These lesions did not change during follow-up, but their clinical significance remains to clarify. Limitations of study include the retrospective design and the small number of patients undergoing intratesticular dye injection, but still this is one of the largest series with long-term follow-up of intratesticular lesions after BL.

LS-LV significantly reduced the risk of hydrocelectomy, irrespective to the use of BL. Intratesticular methylene blue injection was associated with persistent testicular lesions on follow-up ultrasounds in 19 % of cases. More studies are necessary to prove the safety of dye injections into the testis.