Introduction

Microdissection testicular sperm extraction (Micro-TESE) is the standard treatment for non-obstructive azoospermia (NOA). However, the amount of tissue that should be extracted has not been reported. This study investigated the relationship between sample volume and sperm retrieval rate in Micro-TESE.

Methods

The subjects were 208 Asian patients with NOA (mean age: 35.1±5.4 years) who had undergone Micro-TESE at Nagoya City University Hospital or affiliated facilities between July 2007 and December 2014. In this study, testicular volume was measured with a ruler before albugineotomy and after testicular ligature, and the difference in values was set as the sample volume. The subjects were assigned to groups based on sample volume: less than 1.5 mL (group A: n=17), 1.5 mL to 3.0 mL (group B: n=56), 3.0 mL to 4.5 mL (group C: n=91), and more than 4.5 mL (group D: n=44); the groups were then compared. Subjects were also divided into groups based on sampling rate (sample volume/testicular volume before surgery): less than 15% (group a: n=46), 15% to 30% (group b: n=70), 30% to 45% (group c: n=45), and more than 45% (group d: n=37); the groups were again compared.

Results

Sperm extraction rates in groups A, B, C, and D were 39.3%, 17.1%, 20.0%, and 27.0%, respectively (Figure 1). Sperm retrieval rate in group A was significantly higher (p<0.05) than that in group B. No significant differences were noted between the other groups. Sperm retrieval rates in groups a, b, c, and d were 58.3%, 30.3%, 18.6%, and 22.7%, respectively (Figure 2). Sperm retrieval rate in group a was significantly higher than that in groups c and d (p<0.05). No significant differences were noted among the other groups.

Conclusions

In Micro-TESE, the sperm retrieval rate in the group with a low sample volume was significantly higher, possibly because seminiferous tubules containing sperms are easily identified during microsurgery. The findings suggest that if sperms cannot be seen in a low sample volume, there will be no change in the sperm retrieval rate if the sample volume is increased.

Funding

none