CHARLOTTE, N.C. — Carolina Panthers owner Jerry Richardson has made it through the hardest part of heart transplant surgery but still faces an arduous road to recovery.

Dr. Mark Stiegel, who the Panthers said was one of the surgeons who performed Richardson's transplant, wouldn't talk specifically about any patient at Carolinas Medical Center due to privacy laws, but indicated Tuesday night that the most stressful time is over.

Richardson, 72, underwent a five-hour surgery Sunday night and is resting comfortably, according to team officials.

"Your most critical time is actually in the operating room," said Stiegel, who has been performing heart surgeries for 23 years. "Once the heart starts working there are very few things that will alter that process."

Stiegel said the next thing physicians worry about is rejection.

In all, 428 patients received heart transplants at CMC from January 1986 through Dec. 10 of last year. Of those, 94.7 percent of the patients survived one month, 89.5 percent survived one year and 80.7 percent lived at least three years.

"Once the heart is working it's like going downhill," Stiegel said. "You're on the downslope then. It's a matter of them getting through the surgery period and getting them through the operative period which is normally within five to seven days. But the biggest risk is immediate.

"Once you're off the heart-lung machine and the heart is working on its own you feel really good about that."

Age and physical condition also play a factor in a patient's recovery process and potential life span.

Richardson will be kept under the watchful eye of physicians for a long time, particularly the next 12 months.

After a heart transplant, most patients have a biopsy once a week for the first month. After that they go biweekly for the next two months and then about once a month for the rest of the year, according to Ted Frank, a cardiologist and medical director of heart transplantation at CMC.

"Patients undergo frequent biopsy procedures to survey for rejection and intensive evaluation for infection as well as how the organ is working," Frank said.

Said Stiegel: "We follow these people as long as they are here, making sure they are staying healthy and keeping in touch with them regularly. It's an arduous process over the lifetime of a patient."

Frank said once a patient has recovered from the process they encourage them to live an active life with very few limitations.