TESA and Micro-TESE — Surgical Sperm Retrieval Explained

A semen analysis showing zero sperm (azoospermia) is not the end of the fertility road — for many men, it’s the beginning of a surgical one. TESA and Micro-TESE are procedures that bypass the ejaculatory pathway entirely, retrieving sperm directly from the testicular tissue where it’s produced. Paired with ICSI, which needs only a handful of viable sperm per egg, these techniques have made biological fatherhood possible for men who would have been told “impossible” a generation ago.

Understanding Azoospermia First

Obstructive azoospermia (OA): the testes produce sperm normally, but a blockage in the vas deferens, epididymis, or ejaculatory duct prevents it from reaching the ejaculate. Causes include vasectomy, prior hernia surgery, infection, or congenital absence of the vas deferens (often linked to CF gene mutations). Sperm retrieval success rates are very high (nearly 100%) because production is intact.

Non-obstructive azoospermia (NOA): sperm production is severely impaired or absent — from genetic causes, prior chemotherapy, cryptorchidism, or unknown factors. Sperm may still exist in small pockets of the testes even when none appears in the ejaculate. Retrieval success is lower (40–60% with Micro-TESE) but still remarkable.

The Procedures

PESA (Percutaneous Epididymal Sperm Aspiration)

A fine needle extracts fluid from the epididymis under local anaesthesia. Quick, minimally invasive, suited to obstructive cases where the epididymis contains mature sperm. Recovery: minimal, same-day.

TESA (Testicular Sperm Aspiration)

A needle inserted directly into the testicular tissue extracts a small sample. Performed under local anaesthesia or sedation. Works for obstructive cases and some non-obstructive cases where production exists but is reduced. Recovery: a few days of soreness.

Micro-TESE (Microsurgical Testicular Sperm Extraction)

The most advanced option, designed specifically for non-obstructive azoospermia. Under a powerful operating microscope, the surgeon opens the testis and examines the seminiferous tubules directly — identifying and extracting the small areas where sperm production persists. Performed under general or regional anaesthesia, takes 1–3 hours. Recovery: 1–2 weeks of restricted activity, mild discomfort.

Micro-TESE retrieves sperm in roughly 40–60% of NOA cases — compared to 20–30% for conventional (non-microscopic) TESE — because the microscope allows targeted sampling rather than random biopsies. For men with NOA, Micro-TESE at an experienced centre is the recommended approach.

How Retrieved Sperm Is Used

Retrieved samples are small in number and often immotile — which is exactly why ICSI was developed. The embryologist selects viable sperm under high magnification and injects one per egg. Fertilisation rates with surgically retrieved sperm via ICSI are typically 50–70%, and pregnancy rates parallel standard ICSI when female factors are favourable.

Freeze the surplus. Any extra sperm or tissue retrieved should be frozen so the surgical procedure never needs repeating for future cycles or siblings. This is standard practice at experienced centres.

Choosing the Right Centre

Micro-TESE outcomes are highly surgeon-dependent — the difference between an experienced andrologist performing 50+ procedures a year and an occasional operator is statistically significant. Questions to ask:

1. “How many Micro-TESE procedures has your surgeon performed?”
2. “What is your sperm retrieval rate for NOA specifically?”
3. “Is the ICSI lab in the same facility, and do you coordinate retrieval with the partner’s egg retrieval?”
4. “Do you freeze any surplus tissue?”

The third question matters logistically: ideally, the man’s retrieval and the woman’s egg retrieval happen on the same day at the same clinic, so fresh sperm is available for ICSI. If scheduling doesn’t allow this, the retrieved tissue is frozen first and thawed on egg retrieval day.

Before the Procedure

Genetic testing is recommended before Micro-TESE for NOA: karyotype, Y-microdeletion analysis, and CF gene testing if vas deferens is absent. Some genetic causes (complete AZFa or AZFb deletions) predict zero retrieval — knowing this in advance avoids an unnecessary surgery and directs the couple toward donor sperm. Genetic counselling is equally important: some Y-microdeletions will pass to sons conceived via ICSI, who would themselves have azoospermia. Understanding this before treatment is better than discovering it after.

Zero in the ejaculate is a starting point, not an ending. Full male infertility guide · ICSI treatment guide · Ask Pregology for help finding an experienced centre