Dr. Alan W. Hemming, the country’s leading liver surgeon and former chief of the surgical transplantation team at UC San Diego, was quietly replaced for unknown reasons in early June.

According to The San Diego Union-Tribune, Dr. Kristin Mekeel, Hemming’s former colleague, now serves as the interim chief of the surgical transplantation team. Mekeel specializes in liver, kidney, and pancreas transplants. She is a professor in the Department of Surgery who has been awarded the faculty teaching award for her instruction of medical students and residents in transplantation and surgery.

Hemming, recruited by Vice Chancellor of Health Sciences Dr. David Brenner from the University of Florida in June 2009, headed the organ transplantation program at UC San Diego Health for the past nine years. The program was designed to offer advanced diagnostics and innovative approaches for liver resection and transplantation. He was expected to shoulder responsibility for implementing the university’s vision of creating a groundbreaking treatment center for advanced liver disease. Hemming would later be involved in the research and expansion of the donor program for liver transplants.

When Hemming first joined the medical center, he was acclaimed in the university’s press release, which publicized his profound skills as a leading surgeon-scientist in the field of transplantation. The release highlighted his performance on more than 900 liver resections and 500 liver transplants, including a “successful liver transplant for one of the smallest recipients in the world—an infant weighing just over four pounds.”

In the same press release, Hemming stated, “If you have been told that you have untreatable liver disease, there is hope for you here. As a world-recognized academic medical center, UC San Diego has the expertise, resources, and skill to take on the most difficult cases.”

Throughout the years, Hemming received significant attention for his achievements. Most notable was the successful 10-hour surgery he performed in 2016. 54-year-old Frank “Sony” Taitano was the recipient of a new heart and liver transplant. According to the UC San Diego News Center, the operation was not only the first successful heart-liver transplant in the San Diego region, but also an exceptionally rare procedure. In the U.S., less than 10 of these surgeries are performed each year.

Hemming had another major achievement in 2012, when he removed and reconstructed a 27-year-old mother’s diseased liver. The liver was placed back in the patient without any tumors.

Both Jackie Carr and Scott LaFee, Assistant Executive Director of Communications and Media Relations Representative for UC San Diego Health, respectively, had no comment and would not disclose further information regarding the matter. The surgical staff, including Dr. Brenner, declined to comment on the circumstances surrounding Hemming’s replacement or the timeline for appointing a replacement.

Kathleen Lee is a Contributing Writer for The Triton. You can follow her at @katleenlee.