Can we predict the chance of successful epididymal or testicular sperm aspiration following vasectomy?

Purpose of this retrospective study was to investigate if serum markers, men's age, interval since vasectomy, BMI, testicular size and smoking could predict the success of epididymal or testicular sperm aspiration (PESA/TESA) in vasectomized men. Forty-four consecutively performed PESA/TESA procedures were reviewed retrospectively. Motile sperm was retrieved from 77.3% of PESA/TESA procedures. Mean serum Inhibin-B (Inh-B) level tended to be higher in men who had motile sperm retrieved compared to those who had not (180.3 versus 126.2 pg/ml, p = 0.05). Univariate analysis identified serum Inh-B to be the only predictor of PESA/TESA success (r = 0.32, CI: 0.006-0.584, p = 0.046). Serum FSH, LH, T levels, age, BMI, smoking status and interval since vasectomy did not correlate with the PESA/TESA outcome. Inh-B could modestly discriminate between successful and unsuccessful PESA/TESA (AUC= 0.70) with high positive (89.5%) but low negative prediction (36.8%); 58.6% sensitivity and 77.7% specificity at the optimum cut-off level of 166 pg/ml. Positive outcome was only 50% when the Inh-B level was below 100 pg/ml. It is concluded that a high serum Inh-B might reliably predict successful PESA/TESA in vasectomized men. More invasive sperm retrieval procedures could be reserved for men with very low Inh-B or failed PESA/TESA. Future studies with adequate power may confirm our findings.