Intraoperative epididymal sperm cryopreservation during microsurgical vasoepididymostomy for obstructive azoospermia: intracytoplasmic sperm injection outcomes from a single-center cohort.

BACKGROUND: Microsurgical vasoepididymostomy (MVE) is employed as a therapeutic intervention for epididymal obstructive azoospermia (EOA). However, patency is not consistently attained. For such cases, intraoperative sperm cryopreservation during MVE may serve as an alternative strategy, potentially avoiding the need for subsequent surgical sperm retrieval procedures. This study aimed to evaluate the assisted reproductive technologies (ART) outcomes of cryopreserved epididymal sperm obtained during MVE compared to fresh ejaculated sperm and thawed testicular sperm. METHODS: This retrospective study included 117 men diagnosed with obstructive azoospermia (OA) who underwent sperm cryopreservation from epididymal fluid or testicular tissue during MVE between November 2022 and July 2025. To evaluate the clinical utility of this strategy, two control groups were included: intracytoplasmic sperm injection (ICSI) cycles using fresh ejaculated sperm (fresh ejaculated group) and ICSI cycles using frozen-thawed testicular sperm from OA patients who underwent testicular sperm aspiration (TESA) (thawed TESA group). RESULTS: Among the 117 patients who underwent MVE combined with sperm cryopreservation (comprising 73 cases of epididymal sperm and 44 cases of testicular sperm), 29 patients subsequently used their frozen epididymal sperm [thawed microsurgical vasoepididymostomy epididymal sperm (M-ES) group] while 6 patients used frozen testicular sperm for ART. Laboratory outcomes showed that the thawed M-ES group achieved comparable rates of fertilization (0.72±0.24 vs. 0.74±0.24), cleavage (0.99±0.02 vs. 0.99±0.06), and good-quality embryo (0.47±0.34 vs. 0.54±0.30) when compared to the fresh ejaculated group, and higher than the thawed TESA group (0.67±0.24, 0.97±0.12, and 0.46±0.30, respectively). The clinical pregnancy rates of the thawed M-ES group were similar to those of the control groups in both fresh embryo transfer (ET) cycles (40.0% vs. 44.3% vs. 46.2%, P=0.86) and frozen ET (FET) cycles (48.1% vs. 37.2% vs. 41.6, P=0.41). CONCLUSIONS: Cryopreserved epididymal sperm obtained during MVE achieved laboratory and clinical pregnancy outcomes comparable to fresh ejaculated sperm, supporting its preferential use over testicular sperm when epididymal sperm are available. These findings provide a rationale for routine epididymal sperm cryopreservation during MVE as a primary fertility preservation strategy.