The Texas State Medical Board voted Friday to delay until next year final approval of new stem cell therapy rules that could restrict _ or even block _ procedures such as the one Gov. Rick Perry recently underwent on his aching back.

Its 19 members, including a dozen physicians, voiced support for greater oversight but opted to tweak the proposed rules and take them up again at their next meeting in February. If the reworked rules are satisfactory, formal approval could come as early as April.

The Food and Drug Administration hasn't approved using adult stem cells to help people heal from surgery, but experimentation is common. Some scientists tout the possible benefits, including treatment for heart disease, diabetes, and some cancers. Others argue adult stem cell experimentation actually increases the risk of cancer and can cause blood clots.

Perry, 61, a Republican presidential candidate, had stem cells taken from fat in his own body that were then grown in a lab. They were injected into his back and his bloodstream during an operation in July to fuse part of his spine.

The proposed rules would require an independent panel to conduct a comprehensive safety review of any procedure involving stem cells before it is carried out. Without that review, procedures such as the one Perry underwent would not be allowed.

Some noted that new stem cell regulations could have unintended consequences, however, such as limiting the ability of tissue banks to collect genetic material for transplants. As a result, the board asked its staff to modify the rules.

"My sense is, this 80, 85 percent ready for primetime and they're just adding some material," said Leigh Hopper, a board spokeswoman.

Perry, who appoints the board, sent it a letter in July saying he appreciated the responsibility to protect patients. But he also urged members to "recognize the sound science and good work that is already being done, and will continue to be done in the future, in this field."

"We need to ensure that physicians in this state can continue to pursue new technologies and treatments that will benefit all Texans," Perry wrote. "Texas is a leader in innovation in many fields. It is critical that we continue to foster an environment that encourages technological advancement in the health care arena."

Following his surgery, Perry has worn a back brace but maintained his hectic campaign schedule _ though he has begun wearing orthopedic shoes, foregoing his trademark cowboy boots. Adult stem cell therapy is different from using embryonic cells, a controversial technology that the governor opposes.

Lucy Nashed, a spokeswoman for the governor, said Friday that he "expects the Texas Medical Board to review all the facts and make the appropriate decision regarding the use of this promising technology in Texas."

At least 10 states _ including California, Illinois and New York _ have enacted rules governing stem cell research, according to the Interstate Alliance on Stem Cell Research.

The impetus for Texas' proposed rules did not grow out of Perry's procedure but did involve the physician who performed it, Dr. Stanley Jones. The Houston-based orthopedist, who is Perry's doctor and friend, touted the benefits of stem cell therapies at the medical board's June meeting. He said many Americans pay thousands of dollars to undergo treatment abroad and that it is a shame that Texans can't access the treatment in their home state.

Perry also helped push an amendment to a larger health care bill through the Texas Legislature in June creating a state bank to store and cultivate adult stem cells for treatment purposes.

NBC reported in September that the first bank approved by the state _ Celltex Therapeutics Corp. of Houston _ is co-owned by Jones and David G. Eller, the former chairman of the board of Texas A&M University, and a top Perry donor.