Stem cells among techniques used

Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.

We'll be talking about reconstructive urology today with Dr. Akio Horiguchi from Japan and Dr. Mang Chen from San Francisco. They are two of 10 visiting professors in Syracuse for an international reconstructive urology event organized by Dr. Dmitriy Nikolavsky, who is a professor of urology at Upstate and director of reconstructive urology.

Welcome to "The Informed Patient," Dr. Horiguchi and Dr. Chen.

Akio Horiguchi, MD, PhD: Thank you.

Mang Chen, MD: Thank you so much, Amber. It's a pleasure to be here.

Host Amber Smith: Now, Dr. Horiguchi, you're involved in urinary reconstructive surgery and urinary tract revival, and I'd like to ask you about the surgery you offer for urethral stricture. For listeners who are unfamiliar with this, can you explain what causes a urethral stricture?

Akio Horiguchi, MD, PhD: Yes. Urethral stricture is characterized by the spongiofibrosis (scar tissue) and narrowed urethral lumen (channel) caused by various etiologies including trauma and instrumentation to the urethra and inflammation. But most of the strictures is unknown origin.

Host Amber Smith: But it's an issue that needs to be corrected, typically. How do you approach this if catheterization and dilation are not effective? What is the goal of the surgery that you offer?

Akio Horiguchi, MD, PhD: Yes. Generally, transurethral surgery such as urethrotomy or dilation is performed, but it is not generally effective. So, we need to offer urethroplasty (removal and replacement of scar tissue), that is, open reconstruction is recommended for most of our patients. The goal is cure of stricture. It is an important point of the stricture management.

Host Amber Smith: Now, Dr. Horiguchi, can you tell us about the work you're doing with stem cells? But first, would you explain what stem cells are and how they're being used medically?

Akio Horiguchi, MD, PhD: Yes. Stem cell therapy for regenerative therapy is a current issue of promising therapy. In my case, we use buccal mucosa cells harvested from the inner cheek and prepared in the medical laboratory and then introduced to the urethral stricture disease.

Host Amber Smith: So you're able to take from a patient cells from the inside of their mouth on the inside the cheek, and you ...

Akio Horiguchi, MD, PhD: Yes.

Host Amber Smith: ... transfer those into the area where you've got the stricture that you're working on?

Akio Horiguchi, MD, PhD: Yes, exactly. And it is important to note, only small amount of the buccal mucosa is enough. But in contrast, in urethroplasty, open surgery, a large amount of buccal mucosa is required. But in my case treatment of only small amount of buccal mucosa is enough, and expands the cell culture thereafter.

Host Amber Smith: So you only have to take a small portion from inside the cheek. Does it grow, does the tissue sort of grow on its own once you place it in the stricture area?

Akio Horiguchi, MD, PhD: Yeah, exactly. And after expanding the cell culture, we inject the cells inside the urethra. So the invasiveness is much lower than the open urethroplasty.

Host Amber Smith: Interesting.

This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with two visiting professors who specialize in reconstructive urology who are in Syracuse for an international reconstructive urology event at Upstate. Dr. Akio Horiguchi of Japan has been describing urethroplasty and the work he's doing with stem cells. And now we're going to shift to Dr. Mang Chen and the work he does in San Francisco.

Dr. Chen, your specialty is genitourinary surgeries for transmasculine individuals. So these are gender-affirming surgeries for people who were born female, and you and your team will do the penis/scrotal/perineal reconstruction, is that right?

Mang Chen, MD: That's correct, Amber. That's my prime focus in my current profession as a solo private-practice reconstructive urologist.

Host Amber Smith: So can you talk about the different approaches and how you help patients decide which approach is best?

Mang Chen, MD: It depends all on the patient's surgical goals. Many patients prioritize having male or masculine anatomy, being able to urinate through the penis, and even having sexual, penetrative sexual, function with the penis.

And many patients also want a pouchlike, anatomically male scrotum. So that's where I can help them.

Host Amber Smith: So you're able to do that using tissue from the patients, other parts of their body?

Mang Chen, MD: That's correct. So let's say someone comes to me, and they say, "Dr. Chen, I want male-appearing anatomy. I want to be able to stand to pee. I want a pouchlike scrotum, to know that I have basically a masculinized genital region, and I don't want the risk of taking tissue from another part of my body, like my arm or thigh to make a bigger penis. I'm OK with something that's small."

In that situation that patient would be best treated with metoidioplasty, which involves doing something called vaginectomy, where the canal is removed, the mucosa inside the canal is removed and closed. And then you take the minora tissue to extend the urethra from where it is originally to the head of the native penis. Then you take the majora tissue to make a pouchlike scrotum. And then you close the area behind the scrotum, make it flat and masculinized.

For patients who want all those goals, to be able to stand to pee, have a pouchlike scrotum but want the ability to penetrate with intercourse in the future and have a more physiologic or proportional-sized penis, they would need a phalloplasty, which is tissue taken from, most commonly, the arm or the thigh.

That tissue is taken as a big rectangle of skin and fat with its associated nerve and blood vessels. That rectangle is divided into a smaller rectangle and a medium rectangle. The small rectangle gets rolled into a tube we call the urethra. And then the medium rectangle gets rolled around that to create the penis itself. It's the tube-in-tube design.

Host Amber Smith: So what you're describing, is this multiple surgeries or is this one big surgery, where you have a lot of things to do during that operation?

Mang Chen, MD: It can be either. Some centers are more equipped to stage the procedure, so they'll do the penis and the urethra first, and then they do the perineal masculinization part later. Or other centers will do the perineal masculinization first and then the phalloplasty part later.

The plastic surgeons I work with, we prefer to do it all at once because we're equipped to do so. We've been working together for a long time. Our argument for doing it all at once is that it meets the patient's goals the quickest, and in our hands, the safest. Basically we operate together. The microsurgeons will most commonly operate on the arm while I'm operating down below. While I'm doing my part of the procedure -- which is the vaginectomy, extending the urethra, burying the native penis, dissecting out a nerve that goes to the native penis, and then making the majora into a scrotum -- the microsurgeons are harvesting the tissue from the arm.

When they're done, I'm done. We get together, they hand me the penis from the arm. I put a catheter that lines up the arm urethra with the minora urethra. I sew the urethra together. And then the microsurgeons connect the nerve I dissected from the native penis, and that nerve is connected to the sensory nerve of the arm penis so that the new penis has a chance of feeling like a penis, about a year or two later.

Host Amber Smith: I was going to ask about recovery. But, so a patient may not feel the full effects for a couple of years?

Mang Chen, MD: Yes. In general, it's about a year. But it could take as long as four years to start developing sensation in a new penis. But the average is about a year or less.

Host Amber Smith: Now, what happens to the female internal organs, the uterus, fallopian tubes, ovaries? Do you remove those, or do they stay? What happens?

Mang Chen, MD: Great question, Amber. Most patients get a hysterectomy with or without removal of the fallopian tubes and the ovaries prior to surgery, about three months prior. That's the most common scenario. Patients then come to us to get a vaginal removal and then conversion of female anatomy into male anatomy.

Host Amber Smith: Very interesting. Where did you learn your skill? This sounds like it requires not only technical skill, but it sounds like there's some artistry in your work.

Mang Chen, MD: It was kind of learning on the job. At the time, there were no formal training programs, no fellowships in these types of surgeries. My first job was actually was in academic urology at the University of Pittsburgh. And then after three years I was in invited to come out and see these procedures. And selfishly they were very interesting procedures. But then what got me hooked was basically meeting the patients and seeing how amazing they were, how much they go through to get the body they need and deserve.

And then from there it was learning on the job and then basically seeing the issues that arise from the surgery during its evolution, its early evolution. And now the surgery we do is very different from what we did back in 2015.

Host Amber Smith: Lots of progress. Well, I'm very appreciative of Dr. Nikolavsky of inviting both of you to this conference. And, I appreciate you both making time for this interview, Dr. Akio and Dr. Chen.

Mang Chen, MD: Thank you so much, Amber. It was a pleasure to be here.

Akio Horiguchi, MD, PhD: Thank you.

Host Amber Smith: My guests have been Dr. Akio Horiguchi of Japan, and Dr. Mang Chen of San Francisco, both visiting professors at an Upstate event focused on reconstructive urology.

"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.

Find our archive of previous episodes at glenviewelectric.com/informed.

This is your host, Amber Smith, thanking you for listening.