Ex vivo human testes as a practical model to simulate ultrasound-guided testicular cell transplantation for human fertility restoration

Abstract

Objective: To develop an ex vivo model to practice ultrasound-guided injection of cellular material into human seminiferous tubules to simulate testicular cell transplantation (TCT). Design: Simulated TCT injections were performed in human testes removed during orchiectomy. The rete testis was the target site of injection. Successful retrograde infiltration of injected material into the lumen of the seminiferous tubules was detected using ultrasound and confirmed with histology. Setting: Single academic surgical center. Patient(s): Adult patients undergoing orchiectomy for nononcologic indications. Intervention(s): The testes were injected with sonographic contrast (Optison), methylene blue, and fluorescent-labeled cells. Main Outcome Measure(s): A characteristic streaming pattern of sonographic contrast in the testis was used to define sonographic success, and the presence of methylene blue and fluorescent-labeled cells within the seminiferous tubules confirmed histologic success. Result(s): We performed simulated TCT injections in 30 testes obtained from 16 patients undergoing orchiectomy. We were able to achieve sonographic success in 57% of injections and confirmed that sonographic success is correlated with histologic success. Conclusion(s):Testicular cell transplantation injections can be practiced using human testes. As there appears to be a learning curve associated with this procedure, developing this infrastructure to practice these skills is critical before implementation in patients. (Fertil Steril Sci Ò 2021;2:135-40. Ó2021 by American Society for Reproductive Medicine.