Cauda epididymal sperm aspiration as a novel approach for spinal cord injury-associated azoospermia

Study design: Retrospective cohort analysis. Objectives: To determine the most effective sperm retrieval method for men with complete lower-body spinal cord injury (SCI) and azoospermia. Setting: A retrospective observational study conducted at Saint Mother Clinic in Japan, in 2024 using data from 2010 to 2023. Methods: Cauda epididymal sperm aspiration (CESA) was performed in 69 individuals with complete lower-body paraplegia caused by SCI, and sperm retrieval rate, sperm concentration, motility of the retrieved sperm, serum LH and FSH levels, and duration since injury were evaluated. These outcomes were then compared with the results obtained by microdissection-testicular sperm extraction. Results: Sperm retrieval by CESA was successful in 42 cases (60.9%) with a median FSH level of 4.6 mIU/mL, while the remaining 27 unsuccessful cases (39.1%) had a median FSH level of 12.9 mIU/mL. The pregnancy rate was 38.4% (56/146), the miscarriage rate was 19.6% (11/56), the live birth rate was 30.8% (45/146) and the cumulative live birth rate per single CESA procedure was 128.6% (45/35) and the successful (n=42) and unsuccessful (n=27) sperm retrieval groups revealed significant differences in FSH with a cutoff value of 5.95 mIU/mL. Conclusions: CESA achieved a high-quality sperm retrieval rate of 90.6% in individuals with normal FSH levels with minimal physical and psychological burden on the individuals, making it the most patient-friendly retrieval method available.