Spotlight on Dr. Marisa Schwab

Dr. Marisa Schwab recently completed two years as a pediatric surgery fellow at Stanford and will be joining the faculty in Stanford Surgery faculty at the Lucille Packard Children’s Hospital. She is originally from Switzerland and came to the US for her undergraduate education.

Growing up, Marisa always knew that she wanted to be some kind of pediatric doctor, but when she shadowed one of the pediatric surgeons in Los Angeles, she became passionate about pediatric surgery and spent the following 15 years working to achieve this goal.

Marisa went to Georgetown University for medical school and then to UCSF for her general surgery residency before coming to Stanford for her pediatric surgery fellowship.

“It’s been quite a long time in the making,” Marisa said, “but I still carry the same passion and enthusiasm.”

Marisa is Stanford’s first fellow to spend two weeks working at Paris Saclay Hospital, a world-renowned national referring center for biliary atresia located in the center of Paris, France, as part of an international exchange program designed and developed by Dr. Stephanie Chao, Marisa’s mentor.

You had spent your residency research years working in Dr. Tippi MacKenzie's lab investigating fetal molecular therapies for various genetic diseases. Can you tell us about your research?

When I was in college, I became fascinated with fetal surgery after watching a YouTube video. The idea of operating on fetuses while they are still with their mothers was mind-boggling. I was fortunate to go to UCSF for my general surgery residency. UCSF is actually the birthplace of fetal surgery with Dr. Michael Harrison.

I chose to spend my research years in Dr. Tippi MacKenzie’s lab because she is a pioneer for fetal molecular therapies including fetal genetic therapies.

I worked on a variety of fetal molecular therapies, wrote the FDA paperwork, and helped open a phase 1 clinical trial to treat fetuses with lysosomal storage diseases (LSD) by administering enzyme replacement therapy before birth.

We were able to treat the first fetus ever with this technique, which led to a baby with Pompe disease being born with a normal heart and motor function. I also performed a lot of fetal sheep and mouse surgeries for a variety of therapies, which was an unbelievable experience. It fueled my love for fetal diagnostics and therapies, which is what I hope to continue pursuing in my academic career.

You recently went to the Paris Saclay Hospital from May 18^th to June 4^th, 2025. Tell us all about it. What did you do, what was your schedule like, and why did you choose this hospital?

I’m very lucky to have an incredible mentor, Dr. Stephanie Chao, who is one of the Stanford pediatric surgeons. She was approached by Dr. Luca Pio, one of the pediatric surgeons at Paris Saclay. The reason she thought this would be such a strong collaboration is that Paris Saclay is a top referral center in France, with incredible experience in treating patients with hepatobiliary diseases as well as a number of other congenital diseases such as congenital diaphragmatic hernia (CDH), anorectal malformations (ARM), and tracheoesophageal fistula (TEF).

We initiated the partnership by hosting quarterly educational seminars between Stanford and Paris Saclay over Zoom. We chose topics that both institutions were interested in, reviewed recent articles, and compared the management on both sides of the world. Dr. Chao’s goal was that, towards the end of the fellowship, I would go there as part of a formal exchange program, to exchange ideas and see how they practice. While I was there, I was in the operating room with their pediatric surgery team every day. I saw how they diagnose patients, their treatment protocols, surgical techniques, and post-operative management. It was also a chance for me to understand their system as a referral center. Stanford is also a referral center, but most our referrals come from California and neighboring states. It was interesting to see how Paris Saclay gets referrals from other European and North African countries. There are similarities, but on a different scale. It was an incredibly enriching two weeks for me both personally and academically.

Tell us about the Kasai procedure and the volume they undertake.

The thing with pediatric surgery is that we do lots of different kinds of operations to treat a variety of diseases, many of which are very rare. A Kasai is a surgery performed for children with biliary atresia, which means they’re born without functional bile ducts. At Paris Saclay, they do two to three cases of Kasai per month, while at Stanford, we only do about five cases per year.  

The benefit of the French system is that they centralize care. In addition to Kasais, they also do pediatric liver transplants, liver tumor resections, and portosystemic shunts, so they are truly experts in pediatric hepatobiliary surgeries of all types.

They are so comfortable at navigating the hepatobiliary anatomy, and unbelievably skilled, sewing on tiny vessels. It’s a different model than what we have in the US, where all children’s hospitals perform a wide variety of pediatric surgery cases.

Do we have the resources and the infrastructure to operate on these rare cases?

We certainly have the resources, but the question is how to build the patient volume. It’s a different model. What really impressed me is that their healthcare system is much more cost-conscious than ours, yet they perform exceptional surgeries and provide outstanding care.

For example, it was shocking to see how minimal their operating room instrument tables were, all the while performing spectacular surgeries.

What new skills, experiences and procedures did you learn from this visit, and what did they learn from you?

I learned a lot from watching the portosystemic shunts, since these aren’t done widely in the US. I was also very impressed with how they function as a team, with a dedicated operating room staff. They had a lot of questions about how we manage patients since we have similar patient populations. One aspect that is different is how we take care of patients with pediatric cancers. In Europe, patients with renal tumors are more likely to get chemotherapy prior to surgery, while in the US, we generally offer upfront resection. They were curious as to how we deal with very difficult and bulky tumors.

The timing of this exchange, at the end of my fellowship, was perfect. At this point, I feel confident taking care of pediatric patients with many different pathologies and who need a wide variety of operations. Thus, I was able to really delve into the details and understand how they differ from what I’ve learned at Stanford.

What were the challenges?

Honestly, it was a very smooth process. French is my native language so that did help, although most of their surgeons also speak English. Both the Saclay and Stanford teams were incredibly supportive. The administrative staff helped us get all the paperwork done and worked efficiently with our busy schedules on both sides.

Our Global Engagement office worked diligently to turn Dr. Chao’s vision into a reality and helped us address all the hoops to make it happen.

Do you foresee an opportunity to expand this exchange program and build other global collaborations? What is the importance of that, and how could we make that happen?

I think that would be a great idea. Dr. Chao has established contacts with other top institutes in Europe such as Karolinska Institute in Sweden, which is the neuroblastoma center in the country. This will add a new dimension for the Stanford Pediatric Surgery fellows by allowing them to gain more exposure to pediatric surgical oncology.

There are so many ways that we can partner with centers of excellence internationally to expand our footprint and collaborate clinically and academically on research projects.

Global collaboration programs are valuable for our pediatric fellows and expose them to high volume centers. I think it’s also a great way to launch your career as a junior faculty by establishing international relationships that you can build on, by collaborating on research trials and projects

Of course, everybody at Paris Saclay knew the Stanford name, but such in-person initiatives put a face to our institution. Their faculty, residents, or medical students can now easily reach out to me to work together on future projects.

You will soon start a new role as a faculty member at Stanford Surgery - congratulations! How might this experience improve your surgical career?

It was very eye-opening to see another center of excellence that works very differently from us, and it gave me many ideas on how my colleagues and I can improve the already excellent care that we provide to our patients at Stanford’s Lucile Packard Children's Hospital. It was also the starting point for me to launch research projects with Dr. Pio and his colleagues at Paris Saclay.

I’m so grateful to the entire team on both sides. I had an incredible two years at Stanford, but this kind of support and collaboration across departments is really what makes Stanford special.