AIMTo evaluate the outcome of repetitive micro-surgical testicular sperm extraction (mTESE) attempts in non-obstructive azoospermia (NOA) cases, in relation to patients' initial testicular histology results.

METHODSA total of 68 patients with NOA in whom mTESE had been performed in previous intracytoplasmic sperm injection (ICSI) attempts were reviewed.

RESULTSAmong the 68 patients with NOA, the first mTESE yielded mature sperm for ICSI in 44 (64%) (Sp(+)), and failed in the remaining 24 (36%) (Sp(-)). Following their first trial, 24 patients decided to undergo a second mTESE. Of these 24 patients, no spermatozoa were obtained in 5 patients, and Sp(+) but no fertilization/pregnancy were achieved in 19. In these 24 cases, mTESE was successively repeated for two (n = 24), three (n = 4) and four (n = 1) times. The second attempt yielded mature sperm in 3/5 patients from the Sp- group and 16/19 patients from the Sp(+) group. At the third and fourth trials, 4/4 and 1/1 of the original Sp(+) patients were Sp(+) again, respectively. Distribution of main testicular histology included Sertoli cell-only syndrome (16%), maturation arrest (22%), hypospermatogenesis (21%) and focal spermatogenesis (41%). Overall, in repetitive mTESE, 24/29 (82%) of the attempts were finally Sp(+).

CONCLUSIONRepeated mTESE in patients with NOA is a feasible option, yielding considerably high sperm recovery rate. In patients with NOA, mTESE may safely be repeated one or more times to increase sperm retrieval rate, as well as to increase the chance of retrieving fresh spermatozoa to enable ICSI.