Sperm Extraction Procedure
When both a standard semen analysis and an extended sperm search do not yield any sperm, a new state-of-the-art infertility procedure, offered exclusively as Maze, often successfully finds and freezes sperm. Maze specializes in FNN-TSA for patients in Westchester, New York City NYC, Connecticut, and New Jersey.
Maze’s Groundbreaking Sperm Extraction Procedure (GN-SEM)
At Maze Men’s Health, our team—led by Michael A. Werner, MD, FACS, a board-certified urologist and fellowship-trained male infertility specialist—offers one of the most advanced infertility breakthroughs available today: Grid Needle Sperm Extraction & Microfreeze (GN-SEM). This cutting-edge, minimally invasive technique is offered exclusively at Maze for men across Westchester, NYC, Connecticut, and New Jersey, and has helped many couples achieve pregnancy when all other sperm retrieval methods failed.
The Challenge: When No Sperm Are Found in the Ejaculate
For men diagnosed with azoospermia—no sperm visible in the semen—even advanced testing like a standard semen analysis or Extended Sperm Search & Microfreeze (ESSM) may occasionally show no results. Historically, the next step was an invasive micro-TESE (microscopic testicular sperm extraction), which can involve surgical incisions and potential damage to testicular tissue.
GN-SEM offers a dramatically less invasive alternative, combining diagnostic mapping and sperm retrieval in one streamlined procedure.
The Innovation: Sperm Mapping + ESSM = GN-SEM
GN-SEM (Grid Needle Sperm Extraction & Microfreeze) merges the diagnostic precision of Sperm Mapping with the therapeutic power of ESSM—allowing our specialists to locate, extract, and preserve live sperm in one procedure.
- Traditional Sperm Mapping uses a grid drawn on the scrotal skin to guide a series of micro-aspirations (fine-needle biopsies). Each site is analyzed on a slide to identify where sperm might exist.
- ESSM then isolates and freezes motile sperm using advanced microscopic search and microfreezing techniques.
GN-SEM eliminates the need for two separate procedures. Instead of sending tissue to pathology slides (where sperm die during preparation), Maze places aspirates directly into sperm-friendly medium, examines them under ESSM, and freezes any viable sperm immediately—preserving fertility potential the same day.
How GN-SEM Works
Mapping & Aspiration
A grid pattern is drawn across the scrotum. Fine needles collect small samples from mapped testicular sites.
Live Sperm Search
Instead of being killed on pathology slides, the aspirated fluid is placed into sperm-friendly media and examined under ESSM for living sperm.
Immediate Preservation
Any motile sperm discovered are individually isolated and micro-frozen for use in future IVF/ICSI cycles.
No Surgery Required
This needle-based method is performed under local anesthesia, causing minimal discomfort and virtually no downtime.
In one procedure, we both diagnose sperm presence and procure viable sperm—without surgical cutting, stitches, or operating-room recovery.
Who Benefits from GN-SEM
GN-SEM is ideal for men who:
- Have azoospermia and no sperm found in standard semen analysis or ESSM.
- Wish to avoid invasive surgery such as micro-TESE.
- Previously had failed sperm retrieval attempts and want a second chance through a less traumatic option.
At Maze, ESSM alone identifies sperm in 44% of azoospermic men. For those who still show no sperm, GN-SEM provides another opportunity to locate and preserve them—often with success.
Why Maze Leads in Advanced Sperm Retrieval
Dr. Michael A. Werner is one of the nation’s foremost experts in male infertility and microsurgery. He is the only specialist in the US performing both the ESSM and GN-SEM procedures in-house. His experience diagnosing and treating thousands of men since 1994 has allowed Maze to perfect these innovative, fertility-preserving techniques.
Our lab’s expertise in microscopic sperm isolation and cryopreservation ensures that even a single viable sperm can be preserved for IVF with ICSI, offering hope to couples once told they had none.
About Dr. Werner and Maze
About Dr. Werner
About Maze

















Maze facility
Areas served
Patient Stories
Our deepest thanks for your support in our fertility journey
We want to express our deepest thanks for your support in our fertility journey.
We are still very much in the throes of our family building story, but as we reflect back on the last year, the moment we stepped into your office is one of our biggest turning points. We were terrified, and your guidance, reassurance, and compassion during a time of extreme uncertainty for us meant more than words can express. That moment when you let us know that having biological children would be a possibility for us will hold a special place in our hearts for the rest of our lives.
Your ability to create an atmosphere of comfort and understanding sets a benchmark in patient care that is truly unparalleled.
L, NY
I deeply appreciate the efforts you and your staff have made...
Maze has created an experience of gaining insight and comfort with and acceptance of, my post surgical sexual self.
Based on my experience with Maze, I would highly recommend you, your clinicians and staff, to others — your approach and quality of concern and support (and determination!) have been hugely valuable.
A, NJ
I have been a patient for almost 10 years...
If you want to go to an office where everyone there is encouraging, helpful, and sincere then Dr. Werner and staff is the place for you. I have been a patient for almost 10 years and never did I think it was about money for his operation.
They have always gave me clear information and guided me through any procedure or process I was working through. I would recommend this office to anyone that needs help!
SR, NY, 49
I could not recommend Dr. Werner and his great team more highly!
I have been seeing Dr. Werner and his fine staff for a few years now and simply put-its the best medical care I’ve ever experienced. Due in large part to the guidance and healthcare I’ve experienced here I feel like the best version of myself at age 41. I could not recommend this Dr. Werner and his great team more highly! Thank you all for what you do!!
JC, NY, Age 41
I Wish I Could Give Them More Stars!!
This is an amazing place!!!! Not only is Dr. Werner great, but the entire staff is incredible. They have completely changed my life for the better. Only wish I had known about them sooner. I wish I could give more stars!!!
David, NY, Age 39
I am in great, knowledgeable, and experienced hands.
Excellent care and follow up by Dr. Werner and Nick. As a doctor myself, I feel I am in great, knowledgeable, and experienced hands. A+
A, NY, Age 44
To state that Dr. Werner saved my life, would be an understatement!
I have been under his care for almost a decade during which he guided me through successful Peyronies treatment, a penile fracture, erectile dysfunction, and in the end, a life beyond my wildest dreams. Dr. Werner, Nick, Paul, Rima, and his entire staff, have spent so much time investing in my physical health, in an effort to not only solve medical problems, but to maximize my overall quality of life.
Dr. Werner is beyond a great practitioner. He’s a great man. His balance of exemplary knowledge, comprehensive treatment, humor, and individualized patient care, has far exceeded any expectation that I have ever had for a doctor. This is to say that Dr. Werner has always treated me as a human being, first. Therefore, his understanding of the person whom he treats, in addition to only the most sound scientific research, makes his work life-altering.
Over the past 10 years, I have continually peppered his staff with questions and concerns, as I have always felt the need to stay educated. Backed by tremendous patience and humility, Dr. Werner has never made me feel like a number. I feel grateful that I found his office, years ago. To that end, I no longer consider him, Nick, or Paul, mere practitioners, but dear friends. I owe much, if not all of my progress over the last few years, to MAZE MENS HEALTH.
Alix B, NJ, Age 51
Dr. Werner and team are knowledgeable, confident and really care about you as an individual!
My first impressions of Dr. Werner: smart, caring, confident, warm. He really listened to me and demonstrated a high level of confidence that he could help me. He understood the impact my symptoms were having on my life and didn’t minimize them. Paul (therapist) and Kristy (exercise physiologist) were also professional and inspired both calm and confidence.
I was initially referred to Dr. Werner for ED and began using a combination of medication and penile injections. Once Dr. Werner found the right dose for me, I was able to get the best erection I had had in over six months. I later developed Peyronie’s Disease as well. I was fortunate that Dr. Werner had significant experience treating Peyronie’s Disease, as he was able to assess me and recommend Xiaflex injections. While treating my Peyronie’s, Dr. Werner also suggested I begin Shockwave Therapy to further help my ED. Since completing both treatments, not only has my Peyronie’s seen dramatic improvement, but my ability to get an erection has improved 95%!
I feel very positive about my experience with Dr. Werner and Maze. These are good people and they are good at what they do. They understand the problem, treat you with respect and take your concerns seriously. I can’t imagine there’s any sexual health issue Dr. Werner would not be able to help you with! If you do consider coming to Maze, it’s important to stick with it and remember that these are medical issues and results do not happen overnight. I was incredibly nervous when I came in for my first appointment, but Dr. Werner has created an environment and a team at Maze that will immediately put you at ease.
Additionally, you and your partner must be on the same page since treatment is a process and requires both patience and good communication. I’m happy to say my wife and I have seen tremendous benefits, becoming even more communicative and closer as a couple throughout this process. Two years ago, I never would have believed coming in for treatment would have changed our relationship so positively.
D, PA, Age 69
Bottom line is that Dr. Werner and all the staff were wonderful!
Very impressive and professional medical practice. Top staff, rigorous process, timely service and excellent follow-up. There is also a positive and vibrant demeanor projected by everyone in the office that I have not seen in other places. There is extensive testing that can get pricey for out of network patients, but cannot argue with the treatment process, quality and results. Bottom line is that Dr. Werner and all the staff are wonderful!
AP, NY, Age 63
The word I would use for Dr. Werner is “thorough."
In 2009, I came to see Dr. Werner for erectile dysfunction, but I was having symptoms for ten years before I got here! I had seen many other urologists, but they just couldn’t figure it out. When I found Dr. Werner, all that changed.
I was very impressed with the caring and knowledge he possesses. He really went out of his way to find out everything that was a piece of my issues. The word I would use for Dr. Werner is “thorough.”
He discovered that I had low testosterone as well as erectile dysfunction. Once I started treatment he had me come in every 4-6 months to check my numbers and regulate me. Together, we found the right treatment cocktail, and my issues were resolved within 4-6 weeks!*
If you ever feel, at any point in your life, that there is a problem, seek help immediately!
A, NY, Age 47
Dr. Werner combines thoroughness with panache.
Dr. Werner combines thoroughness with panache. I feel like his care is totally comprehensive and I feel total confidence that no details will be missed. I have very high standards and he more than surpassed them all.
R, NY, Age 59
Dr. Werner helped us start a family. We will always be extremely thankful.
How are you, Bat Sheva, and Dr. Werner? We hope all of you are doing well and I’m sure helping people move towards sexual wholeness.
We’re doing really well. Our little miracle from God, Anna Joy, is almost 5 months old now!! She is rolling over, babbles a lot, and has the cutest toothless smile. Stan and I absolutely adore her and marvel every day that God gave us this amazing little girl to take care of. We’re so blessed.
We will never forget how Dr. Bat Sheva, and Dr. Werner played such a vital role in our journey towards parenthood. We will always be extremely thankful to God for you.
Please send our love to them.
S & J, NJ
Most compassionate, friendly doctor.
I have been a patient of Dr. Werner’s for over 21 years and he is the most compassionate, friendly doctor I have ever met.
I look for his advice even outside of his specialty. The same can be said for Nick and all of the staff at Maze.
A, NY, Age 59
Frequently Asked Questions
How long does the no-scalpel vasectomy take?
About 20 minutes; most patients say the recovery is easier than a dental procedure.
When can I drive?
Same day if you only used nitrous (no oral meds). If you took oral meds, arrange a driver.
Is the incision visible?
It’s a tiny opening—no stitches—and often hard to find afterward.
Is it reversible?
Reversal is possible but not guaranteed. Consider this permanent; some patients bank sperm before.
Will insurance cover it?
Many plans reimburse most or all costs. Our team handles claims and pre-authorization.