BACKGROUND: Microsurgical testicular sperm extraction (microTESE) is a sperm retrieval technique indicated in patients with non-obstructive azoospermia (NOA) and cryptozoospermia. The procedure involves extensive tissue dissection, which may result in injury to the testis. Ideally, the minimum amount of dissection necessary to obtain sperm is performed. Surgeons have implemented various models to assist intraoperative decision making in whether to perform dissection unilaterally or bilaterally. Some practices rely on the urologist’s intraoperative assessment or have a bedside embryologist, while others, including our own, have established a separate in-facility embryology lab to examine samples in real time during surgery. There are currently no standardized practices to determine if a unilateral or bilateral microTESE should be performed. A prior single-center retrospective study found that for urologists who only rely on rapid intraoperative assessment, a unilateral extraction was sufficient for nearly 60% of patients. The purpose of our study was to determine if having an in-facility embryology lab resulted in fewer bilateral sperm retrievals.
METHODS: We retrospectively reviewed patients who underwent a microTESE between July 2015 and October 2023 at our institution. In our practice, the sample is initially viewed under microscopy by the urologist in the operating room. If no sperm are visualized, the sample is sent to an in-facility embryology laboratory. The lab staff then calls the urologist with the results. Typically, if sperm are visualized, the retrieval ends. If no sperm are visualized, the surgeon proceeds to the contralateral testis. We collected demographic information, relevant medical history, laterality of the procedure, surgical pathology reports, pre-operative semen analyses, and pre-op/post-op serum hormone testing. We excluded patients with obstructive azoospermia. Statistical analysis was performed primarily through logistic regression modeling.
RESULTS: Among the 57 microTESEs performed, 29 retrievals were unilateral and 28 bilateral. 42 patients underwent microTESE for the indication of nonobstructive azoospermia and the remaining for cryptozoospermia. Among the unilateral microTESEs performed, in-house embryology technologists identified sperm in 11 cases that were not seen intraoperatively by the surgeon. Among the bilateral microTESEs performed, 4 procedures demonstrated this same discrepancy. Additional analysis revealed that there is a significant correlation between the degree of FSH elevation and the likelihood of a bilateral procedure (p-value = 0.01). Furthermore, bilateral procedures were associated with an average increase in procedure duration of 3 hours and 18 minutes (p = 0.001).
CONCLUSIONS: The results of our study validate a practice model that embeds an embryologist and/or infacility embryology laboratory within intraoperative decision making during microTESE. The discrepancy between initial evaluation by urology and the in-facility embryology laboratory indicate that a notable portion of patients (15/57) were spared a bilateral procedure due to our in-house embryology lab. Given the invasive nature of a microTESE and significant increase in procedure duration associated with a bilateral microTESE, this is an important consideration. Additional analysis found that a pre-operative FSH level may be an additional predictor of laterality of the procedure, which may guide preoperative counseling. Additional studies, especially multi-center studies that compare various mTESE practice models would be beneficial.
