Testicular sperm extraction prediction for patients with nonobstructive azoospermia by Raman spectroscopy

OBJECTIVE: To address the need for a noninvasive test to predict testicular sperm extraction (TESE) success for patients with nonobstructive azoospermia (NOA). DESIGN: Retrospective case-control study. SUBJECTS: A total of 20 men aged 29-50 years with NOA who underwent microdissection TESE (microTESE) procedure were divided into positive [TESE(+), N = 10] and negative [TESE(-), N = 10] categories based on the success of sperm retrieval. Seminal plasma samples were obtained before the surgery and used in the study after the microTESE outcome became known. EXPOSURE: wavenumber range obtained with hollow-core microstructured optical fiber (HC-MOF); nuclear magnetic resonance spectral features; reactive oxygen species (ROS) level measured using enzyme-linked immunosorbent assay (ELISA). MAIN OUTCOME MEASURES: Successive sperm extraction by the microTESE procedure. RESULTS: bands related to C-H stretching vibrations, which may be associated with an elevated contribution from lipids in TESE(+) samples. The diagnostic model based on principal component analysis provided 79%/68% accuracy, 0.863/0.810 receiver operating characteristic area under curve, and 77%/66% specificity with 80%/71% sensitivity (13-19/5-12 diagnostic odds ratio) on the training/test set using 5-fold 10-iteration cross-validation. The statistical significance of higher ROS levels in TESE(-) samples was not enough for robust prediction of successful TESE. CONCLUSION: The HC-MOF-enhanced Raman spectroscopy is a rapid, noninvasive, cost-efficient, and easy-to-use method, which can be applied to predict TESE success in men with NOA, revealing differences in biochemical profiles of seminal plasma. Although validation on a bigger cohort is needed, this proof-of-concept study highlights perspectives of the technique for its widespread use in presurgical screening, preventing the risky invasive procedure in the case of low sperm extraction chance.