Spotlight on Dr. Marc Melcher

Marc Melcher, MD, PhD, FACS equates transplant surgery to the ultimate “team sport” – there are potentially hundreds of professionals involved in each transplant both inside and outside the OR who contribute one way or another to making a transplant happen. These include nephrologists, hepatologists, nursing coordinators, nurses, pharmacists, social workers, donor networks, and of course the families of the patients. This huge infrastructure and its associated protocols and processes must be frequently assessed, updated, and efficiently managed to optimize outcomes.

Dr. Melcher was a surgical resident at Stanford before his transplant fellowship, after which he joined the faculty in the Division of Abdominal Transplantation in 2006. He served as the Program Director of the General Surgery Residency and Program Director of the Abdominal Transplant Surgery Fellowship, and is currently the Chief of the Division of Abdominal Transplantation at Stanford Surgery.

Dr. Melcher, tell us about some of the standout milestones and most notable developments that you have witnessed at Stanford’s Abdominal Transplant Surgery program.

I’ve seen several remarkable milestones and advances that have led to huge growth both in our kidney and liver transplant services. The progress we made is a result of our willingness to try new innovations and embrace new strategies to see which ones work the best.

When I first joined our kidney transplant program, I started looking into something called “pair-exchanges,” where you have two pairs of incompatible living donor and recipient combinations, then essentially you can swap between the two pairs to get compatible and successful transplants. We built upon this concept and then worked nationally to help get this more accepted and participated in several long transplant chains. This domino effect – or a daisy wheel effect – enables many more recipients to benefit from these exchanges.

We also worked on developing state-of-the-art desensitization protocols for matching highly sensitized patients at high risk of rejecting transplanted organs and have been successful in transplanting patients who in the past would have been far down on the list.

Most importantly, we’ve made some structural changes in the kidney program in the last two years after taking a deep dive into our processes to identify barriers to efficiency and now started to act on our findings. We are moving through patients on the list much faster and hopefully shortening their wait time.

The liver transplant side also grew dramatically, and that’s well represented by our active waiting list which is now one fifth of what it used to be. Although we are adding patients faster to the list, we are also transplanting them much faster and getting them out of the hospital faster.

Technology has played a role in our rapid advancement, and the hospital enabled us to be aggressive in adopting the latest technologies such as top-of-the-line devices that we that we have adopted to transport and store livers. This helped us use organs that we would have never used before, and transplant organs into patients before they get too sick.

I’m also proud that the program recruited Dr. Kazunari Sasaki four years ago who has been pivotable in increasing our volume. His expertise has really empowered our team to be more proactive and confident in accepting organs that we would not have taken before.

I’m happy with our progress because it increased our ability to serve more patients and improve many more lives along the way.

This has all been about the adult transplant side. Tell us about Stanford’s Pediatric Multiorgan Transplant program and why it is so special.

The pediatric transplant program is a rare gem as there are just a few centers in the country. Our catchment basin is large as it expands out to Nevada, New Mexico, Hawaii, Washington State, and beyond. The pediatric program pulls from a much wider geographic area than our adult program, and it also requires a huge infrastructure.

We do kidney, liver, and small intestine transplants here at our pediatric transplant section; the busiest among them is the kidney program. The pediatric kidney transplant team at Lucile Packard Children’s Hospital Stanford is a national transplant volume leader. In fact, over the past five years, data from the Organ Procurement and Transplantation Network (OPTN) shows we have performed more pediatric kidney transplants than any other U.S. center. In the U.S. News & World Report’s “Best Children’s Hospitals 2024-2025” report, our hospital achieved Honor Roll status and our nephrology program was ranked #7 in the nation.

The program is spearheaded by Dr. Tom Pham, who has grown the program significantly. He has been following an inclusive approach by engaging other faculty to help – Drs. Stephan Busque, Varvara Kirchner and I have been able to participate in the program’s growth.

We also have innovative protocols on both the adult and pediatric programs to induce tolerance in our patients to minimize the amount of post-op immunosuppressant medications. These protocols, which use stem cells, will hopefully improve the post-op quality of life for our patients.

Transplant research is rapidly advancing, and surgical techniques are changing by the day. Where do you think the future breakthroughs in transplant surgery will come from? And what, in your opinion, is the next big breakthrough?

There are thousands of patients waiting for a transplant all over the country, and there is a huge need for organ transplantation. But on the other hand, there are a considerable number of organs that are being discarded when the system fails to deliver them quickly enough following collection from donors.

I think that breakthroughs will be in finding new ways to increase the number of transplanted organs to help more patients, and that includes serious structural changes to be more efficient in allocating the organs and making them available to the patients who need them most in a timely manner. This will get more patients off the list faster.

In terms of technical advances, I believe that there is promising potential for kidney xenotransplants to work more effectively. Kidneys from pigs have already been transplanted to humans with early functional success, but without any long-term success so far. We have a lot of expertise at Stanford in immunosuppressants, and I anticipate that we will have a major role in pushing xenotransplant forward.

Also, there is promising research about freezing organs and keeping them for a longer time, which should reduce the number of discarded organs.  I anticipate tremendous success in that area, as well.

Your research interests are in applying the power of algorithms to increase the number of patients who can benefit from organ transplantation. You have put together a group to apply artificial intelligence to the challenges of assessing donor organs and clinical transplant decision-making. Can you tell us more about that?

There are lots of patients listed in the system and also a lot of organs, so I think that increasing efficiency in matching them is key; having concrete objective algorithms to help with that can really make an impact.

For example, in the paired-exchange strategy that I mentioned earlier to find the best matches between incompatible pairs, if you have a database with a large number of incompatible pairs, it becomes a mathematical algorithm to optimize high-quality matches, starting with the hardest ones to match. In addition, in deceased donor allocation, kidneys that are maybe not perfect might be offered to those lower down the waiting list to allocate them in an efficient way. This requires strong and objective algorithms that balance both fairness and equity in the system.

I also had a project using AI to analyze biopsies of potential liver donors and to assess them carefully to determine what characteristics of that biopsy led to better outcomes.

You recently participated in the ACS-HOPE surgical training initiative that Dr. Thomas Pham helped jumpstart. This is a collaboration with colleagues at University Teaching Hospital (UTH), Zambia to assist them in establishing an independent kidney transplant program. What does that program mean to you, and what is the significant difference that it could make?

It was a rewarding opportunity for me both professionally and personally, I think it was one of my most meaningful international trips.

I am deeply appreciative to the support from both ACS-HOPE and our Global Engagement Program here at Stanford. It’s amazing how they make it possible for us to reach all those places and share with them the expertise that we have at Stanford to make a positive impact on the services they provide to their patients.

I’m super impressed with what Tom Pham had built there and how he was able to establish a consistent US presence there in Lusaka’s UTH hospital by building a sense of community and dedicating his efforts to promote the sustainability of the program.

Building a kidney transplant program in Lusaka, Zambia is a game-changing initiative that will touch the lives of the patients who suffer renal failure in a country that has lacked a formal kidney transplant program. Those patients are on dialysis several days a week, which makes them exhausted and not able to engage with their families and society. Dialysis itself is very costly, and it burdens the country’s health system. So, with the success of this program, we will have a better chance to get patients off dialysis and back with their families, to work and contribute to their society, at the same time it will reduce the cost of the government’s healthcare system.

I believe that success leads to success, meaning that if we succeed in establishing the program through this international collaboration, the hospital, healthcare providers and even the government would be enthusiastic about improving it in every possible way. They will eventually become independent and be able to build their own multidisciplinary teams to improve their services, including the hospital’s infrastructure and nursing care, and maintain frequent follow-up. This way they can advance survival rates and improve the wellbeing of their kidney transplant patients.

Our frequent visits are crucial because the skills that we share will be passed from one surgeon to another in a “train the trainer” concept. It would certainly contribute to building a generation of qualified national surgeons who can do those transplants by themselves.

You were in Lusaka, Zambia for a couple weeks in June, and during your visit you were able to complete three kidney transplant operations together with surgeons from UTH. In your opinion, what’s the potential to establish a sustainable kidney transplant program at UTH?  And what are the challenges?

I’m optimistic that we can help the University Teaching Hospital in Lusaka, Zambia to build a sustainable kidney transplant program. I sensed the high dedication and collaboration of the surgeons, and everyone involved there – including nurses, administrators, nephrologists, hematologists, and surgeons – were proud to be part of this vital program, and I felt their determination to push it further.

Having that said, there are also some challenges that need to be addressed along the way such as resource limitations, OR equipment, surgical disposables, and some lab testing that is difficult to access. These obstacles are to be expected in the beginning, and with some help from our institutions here in the US, I think we can help them kick-start the program and improve it as it goes on. There is definitely a lot of potential.

Global Engagement at Stanford’s Department of Surgery has been actively supporting a variety of global collaborations in the Division of Abdominal Transplant Surgery, including hosting international visiting observers. What do you see this as important for promoting international partnerships?

The Global Engagement program is fantastic; it’s not only helping in the transfer of educational skills to other people around the world, but also through these programs we are educating ourselves – it’s a bidirectional benefit for both sides.

Sometimes I feel that we are isolated, and we live in the bubble of our own system, so going somewhere and learning the way they do things despite their challenges opens our eyes to a whole new spectrum in healthcare and it adds a new dimension to our clinical mindset. Personally, I learned a lot from our colleagues there.

I’m a big fan of engaging with people in other countries and learning more about their culture and social traditions. So, I consider this opportunity very valuable, and I thank everyone who helped in making it happen.