Rete testis thickness is a novel predictor for Johnsen score and sperm retrieval outcomes in azoospermia

Microdissection testicular sperm extraction (micro-TESE) is an important technique for retrieving sperm in cases of non-obstructive azoospermia (NOA). However, the success rate of sperm retrieval using micro-TESE remains suboptimal. This has created an urgent clinical need to identify reliable predictive indicators that can accurately determine which NOA patients are likely to benefit from the procedure. Current literature lacks comprehensive studies correlating non-invasive ultrasound-based testis parameters with micro-TESE outcomes, highlighting a gap in the ability to preoperatively predict surgical success. This study aimed to investigate potential preoperative predictors of surgical success.

We retrospectively analyzed data from 167 men with azoospermia treated at our hospital between January 2020 and December 2024. We investigated the correlations between Johnsen score and various parameters, including testicular volume (TV), rete testis thickness (RTT), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T), using Spearman rank correlation analysis. Additionally, we employed binary logistic regression to evaluate the predictive ability of these parameters for micro-TESE outcomes.

Our findings revealed significant positive correlations of Johnsen score with age, RTT, and TV (r=0.136, 0.783, and 0.706, respectively), and negative correlations with FSH and LH (r=-0.723 and -0.515, respectively). Our binary logistic regression model was Logit(P)=-6.828 + 4.753 × RTT - (-0.059) × FSH + 0.061 × LH. The sensitivity, specificity, Youden index, and area under the curve (AUC) values for predicting the results of micro-TESE were 85.6%, 95.0%, 0.81, and 0.950 [95% confidence interval (CI): 0.927-0.974], respectively.

RTT is strongly correlated with Johnsen score; a combination of RTT, TV, FSH, and LH can serve as a reliable preoperative predictor of micro-TESE outcomes. These findings may improve patient selection for micro-TESE, thereby enhancing the overall success rates of this procedure in NOA patients.