Second chance in fertility: a comprehensive narrative review of redo micro-TESE outcomes after initial failure.

When microdissection testicular sperm extraction (micro-TESE) fails, a redo procedure may be the only option for patients who want a biological child. However, there are many gaps of knowledge surrounding the procedure, which need to be addressed to help clinicians and patients make informed decisions. This review explores redo micro-TESE in the context of nonobstructive azoospermia (NOA). Literature was searched using Google Scholar, Medline, and PubMed. Search terms were "NOA" AND "second microdissection testicular sperm extractions" AND "redo microdissection testicles sperm extraction" AND "repeat microdissection testicular sperm extractions" AND "failed microdissection testicular sperm extractions" AND "salvage microdissection testicular sperm extractions". Only original articles in English were included. A total of nine articles were included, consisting of four retrospective and five prospective studies. The time gap between the first and second micro-TESE varied from 6 months to 24 months. Most of the included studies reported successful surgical sperm retrieval (SSR) in the second micro-TESE in the range of 10%-21%, except in one study where it reached 42%. It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE. Patients with hypospermatogenesis and Klinefelter syndrome (KS) had the highest chance of success in redo surgery. In conclusion, redo micro-TESE following a negative procedure can lead to sperm recovery in 10%-21%. Patients with hypospermatogenesis and KS have a higher chance of success. There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.