The head of the University of Texas System formally announced he would end his five-year tenure to return to transplant surgery.

In a press conference Monday, UT System Chancellor Francisco Cigarroa said he had accomplished everything he’d set out to do as chancellor, and that it always had been his intention to return to medicine full-time. Cigarroa has accepted a job as head of pediatric transplant surgery at the UT Health Science Center at San Antonio.

Cigarroa touted his accomplishments as chancellor, including the establishment of two new medical schools: the University of Texas Rio Grande Valley and the Dell School of Medicine at UT Austin. He also cited his Framework for Advancing Excellence, which the UT Board of Regents adopted in 2011. The plan called for increased engineering education, expanded online learning and the Horizon Fund, which provides seed money for the commercialization of UT research.

The chancellor’s departure comes during a tumultuous time for the Board of Regents, UT Austin President Bill Powers and the Texas Legislature. In December, Cigarroa announced Powers would stay on as president, but cited strained tensions with the board. Meanwhile, a joint committee of lawmakers is investigating UT Regent Wallace Hall, who has been accused of a “witch hunt” against Powers. Cigarroa said the controversy surrounding the UT Austin president had nothing to do with his decision.

“I evaluate all presidents as I’ve always done, based on facts and performance,” Cigarroa said. “I support President Powers, and I will continue to evaluate presidents every day — not only President Powers but all 15.”

Sen. Judith Zaffirini, who has been supportive of Powers, says she believes the decision has more to do with the fight over leadership than Cigarroa would admit.

“Although I am confident that he will deny any disharmony, I am equally confident that his decision was influenced by the continued negative circumstances at hand. His action personifies the harmful repercussions of the current attack on those who pursue excellence, protect the privacy of students and strive for true transparency for all,” Zaffirini said in a statement.

Cigarroa said he will remain as chancellor until his replacement is found, a process UT Board of Regents Chair Paul Foster says will likely to take 4-6 months. He will also continue to serve the board as an adviser for the UT Rio Grande Valley medical school.