Does the FNA sperm retrieval failure prediction model work well for current NOA individuals undertaking risk screening before the operation? Model validation, high-risk population identification and potential alternative sperm retrieval exploration

Non-obstructive azoospermia (NOA), the severe type of male infertility. The objective of this study was to evaluate the predictive accuracy of a prediction model of sperm retrieval failure with fine needle aspiration (FNA).

This study involved 769 NOA patients (dataset 1) undertaking FNA and 140 NOA patients undertaking mTESE (dataset 2). The previous model was validated and then reconstructed for more potential risk factors and better accuracy in dataset 1. The reconstructed model was evaluated in NOA patients with different new variables. The outcomes of the micro- testicular sperm extraction (mTESE) were compared with the predicted outcomes of FNA to evaluate its potential as an alternative surgical sperm retrieval (SSR) technique.

307 (39.92%) males experienced sperm retrieval failure in FNA while 92 (65.7%) males experienced sperm retrieval failure in mTESE. The refined model has 80% overall agreement (n = 616). The reconstructed model had an AUROC of 0.876 (95% CI: 0.850–0.921). The mTESE has significantly higher success rate (34.29%) than the predicted success rate of FNA (5.71%).

Previous model shows good consistency. mTESE can be an alternative SSR method for NOA patients with a high predicted risk of sperm retrieval failure with FNA.