MP43-02: Combination of microscopic testicular sperm extraction (mTESE) and density gradient processing to optimize sperm retrieval and pregnancy outcomes in men with nonobstructive azoospermia (NOA)
Introduction: mTESE with Intracytoplasmic sperm injection (ICSI) is the gold standard for treating infertile couples when NOA in the male is present. However, using conventional tissue processing techniques, many patients will remain negative for sperm on mTESE. Standard practice in assisted reproduction technology (ART) does not utilize the density gradient centrifugation process following mTESE. We hypothesize that gradient utilization can enrich sperm retrieval following mTESE. Methods: Men with NOA underwent mTESE from 2019-2022 by a single surgeon. The biopsy specimens underwent mechanical dissection. Subsequent tissue processing and gradient wash were carried out through a gradient column including 90% and 50% gradient solution diluted in standard sperm wash medium. Upon verification of sperm, the post-gradient sperm and remaining un-dissociated tissue were cryopreserved separately. On the day of ICSI, the frozen gradient sperm were thawed to recover viable sperm. If needed, frozen tissue was thawed, subjected to mechanical dissociation, and a subsequent gradient to obtain enough viable sperm. Fertilization and embryo development were assessed morphologically with the Embryoscope and genetically with preimplantation genetic testing for aneuploidy (PGT-A). Following embryo transfer, biochemical (ß-HCG) and clinical (gestational sac) pregnancy were assessed. Results: Overall, 24 male patients (36 ± 1.5 years old) with NOA underwent mTESE for an average operating time of 110.6 ± 6.9 minutes (range: 37-177). The primary sperm identification rate after mechanical dissociation of tissue was 37.5% (n=9). The use of the density gradient led to an overall sperm retrieval rate of 70.8% (n=17) (p < 0.05) and secondary sperm retrieval rate (sperm identification in initially negative patients) of 53.3% (n=8). Retrieved sperm were cryopreserved to be used for ICSI. Thirteen couples (average female age and AMH 32.1 ± 1.6 and 3.2 ± 0.8 ng/ml respectively) underwent ICSI using extracted sperm. The overall fertilization, per-cycle pregnancy, and per-transfer pregnancy rates were 66%, 76%, and 100% respectively. Amongst these couples, 6 underwent PGT-A, and 70.0% of tested blastocysts were euploid. Conclusions: Utilization of mTESE with subsequent gradient technology may serve as a highly sensitive sperm detection and enrichment method for NOA patients in order to obtain superior ART outcomes. SOURCE OF Funding: NA
