O-263 The risk of hypogonadism after microdissection testicular sperm extraction (micro TESE) in non-obstructive azoospermia (NOA) patients with various etiologies
Authors: Yamaguchi K , Ishikawa T , Mizuta S , Doi K , Takaya Y , Suzuki Y , Ohara Y , Doshida M , Takeuchi T , Matsubayashi H 
Published: July 2024

Abstract

Study question
What is the risk factor of hypogonadism after micro TESE in NOA patients?

Summary answer
Klinefelter syndrome (KS), past history of cryptorchidism, preoperative testicular volume &lt;8 ml or testosterone &lt;287 ng/dL are significant risk factors of hypogonadism after micro TESE.

What is known already
Micro TESE combined with intracytoplasmic sperm injection (ICSI) is currently standard procedure to treat infertility in cases of NOA. Although many studies have reported the effectiveness of the treatment concerning about sperm retrieval rates (SRR) and the live birth rates, data on safety, especially on the risk of hypogonadism, are limited. Most previous studies, including our past study, regarding the risk of hypogonadism after TESE have been limited to relatively few in number of patients and the investigations only of the changes of mean serum testosterone levels.

Study design, size, duration
This study retrospectively investigated 535 NOA patients including 336 cases of unexplained NOA, 91 KS, 16 other chromosomal abnormalities, 31 azoospermia factor (AZF)c deletions, 31 past history of cryptorchidism, and 30 post anticancer chemotherapy, who had undergone micro TESE at our institution from September 2013 to August 2018. All of them had been examined serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels before and at least once in 1-3 months after micro TESE.

Participants/materials, setting, methods
In this study, hypogonadism was defined as total testosterone &lt;250 ng/dL, which is established by the Japanese Society of Men’s Health as diagnostic criteria for late onset hypogonadism syndrome, and/or starting testosterone replacement therapy (TRT). We assessed risk factors of hypogonadism after micro TESE using indicators such as age, preoperative testicular volume and testosterone levels, past medical history, unilateral or bilateral, first time or not micro TESE.

Main results and the role of chance
In total of 535 men, FSH and LH after micro TESE significantly increased vs baseline (26.2 vs 29.9 IU/L, 9.6 vs 12.8 IU/L, respectively). On the other hand, testosterone levels significantly decreased after surgery (351.2 vs 297.5 ng/dL). Although postoperative hypogonadism was found in 42% (227/535), many of whom were cases of KS or preoperative testosterone levels &lt;250 ng/dL. Sixteen men with KS, 3 men with unexplained NOA, and 2 men with past history of cryptorchidism started TRT because they complained clinical symptoms after micro TESE. Of the 21 men who started TRT, only 5 had new-onset low testosterone levels after micro TESE. According to the assessment of any association of various indicators and low postoperative total testosterone levels using multiple logistic regression analysis, significant risk factors of hypogonadism early after micro TESE were cases of KS (OR 11.4, 95% CI 4.4-29.9), preoperative testosterone levels &lt;287 ng/dL (OR 7.5, 95% CI 4.7-12.0), preoperative testicular volume &lt;8 ml (OR 3.9, 95% CI 2.3-6.4), past history of cryptorchidism (OR 2.9, 95% CI 1.1-7.8).

Limitations, reasons for caution
Most examinations of postoperative hormone levels were performed in short-term period after micro TESE, so we could only assess the risk of postoperative hypogonadism in a short time course in this cohort study.

Wider implications of the findings
The strength of the current study is that the risk factors of hypogonadism after micro TESE was assessed in a large population of NOA men with various etiologies. The results of this study provide useful clinical information about the risk of postoperative hypogonadism for NOA patients considering micro TESE.

Trial registration number
not applicable