Duration of microdissection testicular sperm extraction procedures: relationship to sperm retrieval success

We evaluated the operative time of microdissection testicular sperm extraction in successful and failed procedures to identify the chance of sperm retrieval during longer microsurgical procedures.

A total of 793 men with nonobstructive azoospermia underwent a first attempt at microdissection testicular sperm extraction from January 2000 to September 2009. Clinical factors were analyzed, including age, testicular volume, endocrinological data and histology. Operative time was calculated from incision until the procedure was terminated.

Testicular sperm were successfully retrieved in 57% of the men. Sperm were found within 2, 2 to 4 and 4 to 7 hours in 89%, 30% and 37% of the men, respectively. There were no differences in preoperative clinical characteristics, age, follicle-stimulating hormone, testicular volume, incidence of a Klinefelter's syndrome diagnosis and distribution of most advanced histopathology in patients in the 3 operative time groups. In men in whom sperm were retrieved the clinical pregnancy and live birth rates were 48%, 45% and 29%, and 37%, 30% and 29% for operative times up to 2, 2 to 4 and 4 to 7 hours, respectively (p >0.05). ROC curve analysis of the different operative times for detecting sperm showed that 125 minutes was the most accurate time (AUC 0.81) with 84% sensitivity and 95% specificity.

The chance of sperm retrieval during microdissection testicular sperm extraction was best during the first 2 hours of the operation. However, sperm were still found in up to 37% of men who required greater than 4 hours of microdissection. Retrospective analysis of our data indicated no cutoff point after which sperm retrieval was uniformly unsuccessful.