TESA and PESA: Sperm Retrieval Procedures Explained

For men with azoospermia — no sperm in the ejaculate — or with sperm so severely affected that natural conception or even IUI is impossible, surgical sperm retrieval procedures offer a direct path to fatherhood. These procedures bypass the natural ejaculatory route and extract sperm directly from the epididymis or testis — where sperm are produced and stored. Retrieved sperm are then used with ICSI to fertilise the partner's eggs.

The main procedures — PESA, TESA, and micro-TESE — differ in technique, invasiveness, sperm yield, and the clinical situations in which they are appropriate. Understanding these differences helps couples ask the right questions and arrive at consultations prepared.

Why Surgical Sperm Retrieval Is Needed

Two situations primarily drive the need for surgical sperm retrieval:

• Obstructive azoospermia: Sperm production is normal, but a blockage prevents sperm from reaching the ejaculate. Sperm are present in the epididymis and/or testis and can be retrieved surgically.
• Non-obstructive azoospermia: The testes produce little or no sperm, but in some men, focal areas of active spermatogenesis exist and can be identified and retrieved with the right surgical technique — specifically micro-TESE.

Additionally, testicular sperm may be used in men with ejaculated sperm — specifically those with very high DNA fragmentation — because testicular sperm have not yet been exposed to the oxidative environment of the epididymis and reproductive tract, and therefore typically have lower DNA fragmentation.

PESA: Percutaneous Epididymal Sperm Aspiration

What It Involves

PESA is performed under local anaesthesia (or occasionally light sedation). A fine butterfly needle is inserted directly through the scrotal skin into the epididymis — the coiled tube on the back of each testis where sperm mature and are stored. Epididymal fluid containing sperm is aspirated and examined in the laboratory for the presence of motile sperm.

Who It Is For

PESA is primarily used for obstructive azoospermia — men with a normal sperm-producing testis but a blockage in the epididymis or vas deferens. It is particularly appropriate for:

• CBAVD (congenital bilateral absence of the vas deferens)
• Epididymal obstruction from previous infection
• Post-vasectomy azoospermia where reversal is not planned

Advantages and Limitations

PESA is the least invasive sperm retrieval procedure — it can be performed as a clinic procedure without general anaesthesia. Recovery is rapid, typically 1 to 2 days. The limitation: epididymal sperm may be less mature than testicular sperm in some situations, and PESA retrieval is less reliable in non-obstructive cases where no sperm are stored in the epididymis.

TESA: Testicular Sperm Aspiration

What It Involves

TESA involves inserting a needle (usually slightly larger than a PESA needle, or with an attached syringe creating negative pressure) directly into the testicular parenchyma and aspirating a small amount of testicular tissue and fluid. The aspirated material is examined for the presence of sperm.

Who It Is For

TESA is used for both obstructive and non-obstructive azoospermia. For obstructive cases, TESA is an alternative to PESA — testicular sperm are always present when obstruction is the cause, and TESA is effective and minimally invasive. For non-obstructive cases, TESA is a first-line attempt — if sperm are found, they can be used; if not, the more invasive micro-TESE provides higher retrieval rates.

Open Surgical TESE

A variant of TESA involves a small open incision in the scrotum and direct removal of a small piece of testicular tissue for laboratory processing. This yields more tissue than needle aspiration and may find sperm when needle TESA has not — but involves a small incision and slightly longer recovery.

Micro-TESE: Microsurgical Testicular Sperm Extraction

What It Involves

Micro-TESE is the most advanced and most effective sperm retrieval technique for non-obstructive azoospermia. It is performed under general anaesthesia by a urologist with microsurgical experience. The testis is opened with a midline incision and examined under an operating microscope at 16 to 25x magnification.

At this magnification, seminiferous tubules that are larger and more opaque — indicating potentially active spermatogenesis within — can be distinguished from the smaller, translucent tubules characteristic of areas with no sperm production. These larger tubules are selectively biopsied.

The biopsy specimens are immediately examined by an embryologist in an adjacent laboratory. If sperm are found, they are used immediately with ICSI or vitrified for use in a planned cycle. If no sperm are found, the procedure concludes without further testicular damage beyond the targeted biopsies.

Why Micro-TESE Is Superior to Standard TESE for NOA

In non-obstructive azoospermia, sperm production — if it exists — is focal and patchy. Standard TESE samples random areas of the testis and may miss the small islands of active spermatogenesis entirely. Micro-TESE systematically searches the entire testis under magnification, targeting the areas most likely to contain sperm. This gives micro-TESE a retrieval advantage of approximately 1.5 to 2 times that of standard TESE in NOA.

Sperm Retrieval Rates with Micro-TESE

• Klinefelter syndrome (47XXY): 50 to 60%
• AZFc Y chromosome microdeletion: 50 to 70%
• AZFa or AZFb deletion: Near-zero — not recommended
• Sertoli cell-only syndrome: 15 to 30%
• Maturation arrest: 30 to 60% depending on level of arrest
• Hypospermatogenesis: 70 to 80%

Timing and Coordination with IVF

Surgical sperm retrieval is coordinated with the female partner's IVF cycle. Sperm retrieved on the day of egg collection can be used fresh — the ideal scenario. Alternatively, retrieved sperm can be vitrified in advance, and the female partner's cycle proceeds to egg collection knowing that sperm are available.

For men with non-obstructive azoospermia where retrieval is uncertain, some couples opt for a diagnostic retrieval cycle (attempting sperm retrieval without a planned concurrent IVF cycle, to confirm that sperm exist before starting the full female treatment). This is a practical option when uncertainty about retrieval outcome is high.

Frequently Asked Questions

Q1. Is micro-TESE painful?

The procedure is performed under general anaesthesia — it is not experienced during the operation. Post-operatively, mild to moderate scrotal discomfort is typical for 3 to 7 days, managed with standard analgesics and scrotal support. Most men return to light activity within 1 to 2 weeks. Heavy physical work and exercise should be avoided for 4 to 6 weeks. Long-term testicular function — testosterone production — is generally preserved after micro-TESE when performed by an experienced microsurgeon.

Q2. Can we freeze sperm retrieved during micro-TESE?

Yes — sperm retrieved during micro-TESE can be vitrified and stored for use in future IVF cycles. This means a successful retrieval session does not need to be repeated for each IVF attempt — the frozen sperm can be used across multiple cycles. This is particularly important for couples where the female partner has good ovarian reserve and may need multiple egg collections.

Q3. What if micro-TESE fails — is there any other option?

If micro-TESE finds no sperm, donor sperm IVF is the primary remaining option for the couple to have a genetically related child (related to the female partner). This is a significant emotional turning point, and psychological counselling support is important. Some couples also explore adoption, embryo adoption, or childfree living. At Solo Clinic, these conversations are handled with compassion and without judgment.