Dr. Roll completed both general surgery training and the abdominal organ transplant fellowship at the University of California San Francisco. During his training, Dr. Roll spent 2 years in Dr. Holger Willenbring's laboratory investigating liver cell therapy, as well as normal and pathologic liver regeneration. After fellowship Dr. Roll moved to England to become a Senior International Fellow in Liver Transplant and Multi Organ Procurement at Queen Elizabeth Hospital, Birmingham, one of the busiest liver transplant departments in the United Kingdom. There he gained valuable experience in the blossoming field of DCD liver transplant and normothermic machine liver perfusion prior to returning to UCSF.

Since returning to UCSF in 2015, Dr. Roll has specialized in abdominal organ transplantation for both adults and children, including liver and kidney transplant surgery from living donors, complex hepatobiliary surgery, and kidney autotransplants for intractable ureteral problems. He also performs general surgery in patients with end-stage organ disease and patients taking immunosuppression. His expertise includes using minimally invasive surgical techniques.

Within UCSF, Dr. Roll is an investigator on several clinical trials looking at outcomes for organ transplant recipients and advance organ preservation. He has leadership roles in patient safety and quality improvement at UCSF, in addition to teaching medical students and residents in multiple forums. Outside of UCSF, he serves on the editorial board of multiple peer reviewed journals.