Gov. Mark Dayton will undergo back surgery Friday morning at Mayo Clinic in Rochester, another in a series of health complications the second-term governor has endured in recent years.

Dayton's office released a statement saying the surgery is similar to procedures Dayton had in 2012 and 2015, which fused vertebrae in his lower back.

"Anyone who has observed my walking in recent months has seen that I have difficulties with my leg strength and, occasionally, with my balance. My doctor believes that this procedure will help with both conditions," said Dayton, 71, in the statement.

Dayton, a Democrat, is not running for re-election. He is the oldest governor in the state's history and often makes self-deprecating jokes about his health challenges.

He will undergo general anesthesia during the surgery and be hospitalized for a few days, but he'll be in frequent contact with staff and commissioners, Dayton said.

"It's ... mostly on a different area of the spine but also on one area that did not heal properly after the last surgery," said Dr. Jeremy Fogelson, the Mayo surgeon who has performed all the procedures. "It is not common for patients with this condition to need multiple procedures, but it does happen in a small percentage of patients."

In 2017, Dayton fainted during his State of the State speech in the House chamber, which was attributed to dehydration. The next day, he announced that he had been diagnosed with prostate cancer, which was successfully treated at Mayo.

In recent years Dayton, who walks with a cane, has frequently worked at the governor's residence, where staff, commissioners, lawmakers and constituents arrive for meetings.

As his tenure winds down, Dayton's schedule has included less of the statewide travel he rigorously maintained in previous years. He will leave office at the beginning of January.

The lieutenant governor is Michelle Fischbach, a Republican. She ascended to the role from her position as Senate president, as called for in the state Constitution, after Dayton appointed then-Lt. Gov. Tina Smith to the U.S. Senate following the resignation of Al Franken.

U.S. Rep. Tim Walz, a fellow Democrat, and Hennepin County Commissioner Jeff Johnson are in a race to succeed Dayton as governor.

J. Patrick Coolican • 651-925-5042