Don Ho, Hawai'i's most famous entertainer, has undergone an experimental heart procedure in a hospital in Bangkok, Thailand — a last-resort effort to maintain a regular heartbeat and extend his life.

Ho, 75, had the surgery Monday night. The procedure, called VesCell Adult Stem Cell therapy, involves an injection of the patient's stem cells from his blood directly into his heart muscle to treat heart disease. TheraVitae, a two-year-old U.S.- and Israeli-run company, developed the treatment, which improves the heart's pumping ability by 20 percent to 70 percent, according to initial studies based on earlier procedures. The therapy is not available in this country.

Dr. Edward N. Shen, Ho's cardiologist at The Queen's Medical Center, said he recommended the treatment because conventional surgery is not an option.

"His heart muscle is weak; the condition is called cardiomyopathy," Shen said. "By drawing his blood and injecting the stem cells into his injured muscle, the hope is that the stem cells will replace the injured muscle. For him, we can't put in a new muscle."

Shen has been treating and medicating Ho for several years and installed a pacemaker a few months ago.

"The (VesCell) procedure is so new, it's not yet approved in this country, so it has to be done outside," he said. "I believe only 30 people have undergone the surgery.

"Medication will continue, but we don't know how much (the stem cell treatment) will benefit him. We'll have to monitor."

Shen said it may be three to five years before such therapy can be administered in this country.

Ho has been in an intensive care unit but his condition is stable, said Ed Brown, his one-time manager and lifelong friend based in Los Angeles. Brown sought out the relatively new treatment after Shen "began to think that Don had no other option but to consider the stem cell treatment."

Brown said if all goes well, Ho will return home within two weeks and could be back performing at the Waikiki Beachcomber Hotel before Christmas.

Haumea Hebenstreit, Ho's assistant, is with him in Bangkok and told Brown "his vitals are excellent, the surgeons are thrilled with the results, his color terrific."

"And he's already giving Haumea lighting cues, music cues and songs he'd like to sing when he returns home," Brown said. "He's treating this like a cakewalk. But as we both know, it's still a risky business."

Ho, a 1949 graduate of Kamehameha Schools, gained notoriety while working at the now-defunct Duke Kahanomoku's in Waikiki from 1964 to 1970. The lounge was a hot spot for local and visiting entertainers, who would stop in to watch Ho perform or join him on stage. His fame spread to the Mainland after he appeared at the Cocoanut Grove in Los Angeles in 1966. His sold-out shows led to appearances at the Sands in Las Vegas, Harrah's at Lake Tahoe and at other hot spots in New York and Chicago. He's also made guest appearances with Johnny Carson, Joey Bishop and Art Linkletter.

His fame spans generations. In 2003, he appeared on Comedy Central's "Insomniac With Dave Attel" when the nightlife show came to the island.

Ho's friends said he had been lethargic the past few months and had been hospitalized in August because of an irregular heartbeat. He continued to perform at the Beachcomber and do carpentry work around his house — his hobby when not on stage — but it started to take its toll. Mostly, he would be short of breath, Brown said.

"His strong medication was doing the job but these inhibitors slowed down his heartbeat, Brown said. "And the pacemaker would go off and give a sting at the worst possible time, like when he's singing 'Tiny Bubbles.' That's why he gave up working (a few months back) and was hospitalized — to get some rest.

"This stem cell therapy was the last resort. It's been frightening; his muscle (heart) was deteriorating and surgery would not improve his condition. Even with his pacemaker, he was suffering."

Ho initially went to Pittsburgh to consult with University of Pittsburgh cardiologist Amit Patel, who developed the treatment in the U.S. The relatively simple procedure requires the drawing of 250 cc to 300 cc of blood, less than a standard donation, from which the stem cells are isolated and multiplied through a patented process. Several million stem cells are inserted with an angioplasty catheter into the patient's arteries or heart, using procedures developed by Patel. The stem cells grow into new tissue that improve the pumping capacity of the heart and these cells are considered safer than those derived from bone or muscle tissue.

Ho didn't qualify for FDA-approved clinical testing in this country because his condition was not as bad as other prospects. Patel referred him to a Bangkok facility that has been doing the stem cell treatment.

Time magazine described it as "the Holy Grail of 21st century medicine," because it enables the heart to function more effectively, even though the treatment still is experimental. Eligibility is based on a doctor's "no other option" analysis for the patient, meaning that conventional treatments such as angioplasty and bypass surgery have been exhausted or deemed unsuitable.

Because the stem cells for this procedure are from the patient's blood, the therapy is not as controversial as the stem cells taken from human embryos. And the cells appear to trigger natural healing mechanisms that enable heart tissue to recover some of its functions.

Reach Wayne Harada at wharada@honoluluadvertiser.com.