http://www.post-gazette.com/pg/08065/862406-114.stm
Old metal heart valve did its job for 42 years
Wednesday, March 05, 2008
By Mark Roth, Pittsburgh Post-Gazette
First of two parts
It took a licking and kept on clicking.
That's one way of describing what an Israeli surgeon found last year while doing open-heart surgery on a 65-year-old man in Haifa.
While putting in a prosthetic mitral valve, Dr. Dan Aravot could see firsthand that the patient already had an unusual metal "ball and cage" aortic valve in his heart, the kind that sometimes would audibly click with every heartbeat as blood pressure shot the ball to the top of its titanium cage. The valve had worked flawlessly for 42 years, and even more amazingly, was not held in place by stitches, but by several tiny U-shaped hooks.
Dr. Aravot had to remove the metal valve so he'd have enough room to put in the new mitral valve. After the operation, his colleague, Dr. Amnon Zlotnick, started doing research to find out who had made the valve.
His discovery? It had been invented in the early 1960s by Dr. George Magovern Sr. of Allegheny General Hospital and his engineer partner, Harry Cromie.
In an article published in the journal Circulation, Dr. Zlotnick said the Magovern-Cromie valve is the oldest documented functioning artificial heart valve ever discovered.
What he didn't know is that this type of valve also kept Dr. Magovern from giving up on surgery.
When he first began doing aortic valve replacements in the early 1960s, Dr. Magovern said in a recent interview, it took him nearly 45 minutes to suture the metal valve in place as the patient's blood was rerouted through a heart-lung machine.
Not only were the patients very sick when he got them, he said, but the lengthy time their hearts were "off line" meant that most of them died after surgery.
Facing a 90 percent mortality rate in his patients, Dr. Magovern said, "I was about ready to quit doing these surgeries," and it took a heart-to-heart talk with his surgical chief to dissuade him.
If only he could cut down on the time the patient's heart was kept chilled and not beating, Dr. Magovern thought.
And since most of his time was spent suturing the new valve in place, he came up with the idea of creating a sutureless valve.
He wasn't quite sure how to design the valve, though, and when he stopped at a machine shop in Aspinwall one day to ask the owner about it, the man was clearly indifferent.
"The guy said, 'Well, how many of these would you sell?' He absolutely wasn't interested."
But Mr. Cromie, an employee of the shop, was intrigued, and he stopped Dr. Magovern on his way out and told him he'd like to tackle the project.
"I said, 'Your boss said no, and he said, 'Well, I have a machine shop at home in my garage in Mt. Lebanon.'*"
That is how their partnership was formed, and over the next 20 years, Dr. Magovern estimated he put in more than 1,000 of the ball-and-cage valves.
Dr. Magovern said it took him only about three or four minutes to put the sutureless valve in place.
In the days when the science of cooling down the heart during open-heart surgery hadn't yet been refined, the much shorter installation time made a huge difference.
With the new valve, he said, he went from a 90 percent mortality rate to a 90 percent survival rate.
Mr. Cromie got a patent on the valve, and eventually, he went to work for Baxter Healthcare of Deerfield, Ill., which purchased the rights to the invention and is still one of the nation's leading artificial valve makers.
Dr. Magovern, who will turn 85 this year and whose sons took over the cardiac surgery department at Allegheny General after he left, said he wasn't particularly surprised to learn that his valve was still working in the Israeli man after 42 years.
A 25-year review of the ball-and-cage valve done in 1989 showed many of them were still functioning, he said, and recently, a patient he had operated on when the man was about 20 called him to let him know his valve was still working away after about 50 years.
A quick look at the statistics of the human heart shows how important it is to have reliable prosthetic valves. The heart beats about 80 times a minute, which means that over the course of a year, the heart's four valves open and close more than 42 million times. In an 80-year lifetime, they do their job more than 3 billion times.
Today, there are 80,000 to 90,000 artificial valve implants done every year, said Dr. Wolf Sapirstein, chief medical officer of the Division of Cardiovascular Devices of the U.S. Food and Drug Administration.
The ball-and-cage valve was eventually replaced by other kinds of designs, but metal valves still account for about a third of all heart valve surgeries.
The downside of metal valves is that they require patients to take blood thinners the rest of their lives to prevent clots that can form as blood rushes turbulently past the metal openings.
Because of that, valves made of animal and human tissue now dominate the prosthetic valve market, even though they tend to wear out after 10 or 15 years because of calcification.
The sutureless valve not only kept Dr. Magovern in his chosen field -- he estimates he did two valve surgeries a day, three days a week for more than 20 years -- but it played to his particular surgical strengths.
"I wouldn't say I was particularly skillful," he said from his winter home in Florida. "But I was fast."
Old metal heart valve did its job for 42 years
Wednesday, March 05, 2008
By Mark Roth, Pittsburgh Post-Gazette
First of two parts
It took a licking and kept on clicking.
That's one way of describing what an Israeli surgeon found last year while doing open-heart surgery on a 65-year-old man in Haifa.
While putting in a prosthetic mitral valve, Dr. Dan Aravot could see firsthand that the patient already had an unusual metal "ball and cage" aortic valve in his heart, the kind that sometimes would audibly click with every heartbeat as blood pressure shot the ball to the top of its titanium cage. The valve had worked flawlessly for 42 years, and even more amazingly, was not held in place by stitches, but by several tiny U-shaped hooks.
Dr. Aravot had to remove the metal valve so he'd have enough room to put in the new mitral valve. After the operation, his colleague, Dr. Amnon Zlotnick, started doing research to find out who had made the valve.
His discovery? It had been invented in the early 1960s by Dr. George Magovern Sr. of Allegheny General Hospital and his engineer partner, Harry Cromie.
In an article published in the journal Circulation, Dr. Zlotnick said the Magovern-Cromie valve is the oldest documented functioning artificial heart valve ever discovered.
What he didn't know is that this type of valve also kept Dr. Magovern from giving up on surgery.
When he first began doing aortic valve replacements in the early 1960s, Dr. Magovern said in a recent interview, it took him nearly 45 minutes to suture the metal valve in place as the patient's blood was rerouted through a heart-lung machine.
Not only were the patients very sick when he got them, he said, but the lengthy time their hearts were "off line" meant that most of them died after surgery.
Facing a 90 percent mortality rate in his patients, Dr. Magovern said, "I was about ready to quit doing these surgeries," and it took a heart-to-heart talk with his surgical chief to dissuade him.
If only he could cut down on the time the patient's heart was kept chilled and not beating, Dr. Magovern thought.
And since most of his time was spent suturing the new valve in place, he came up with the idea of creating a sutureless valve.
He wasn't quite sure how to design the valve, though, and when he stopped at a machine shop in Aspinwall one day to ask the owner about it, the man was clearly indifferent.
"The guy said, 'Well, how many of these would you sell?' He absolutely wasn't interested."
But Mr. Cromie, an employee of the shop, was intrigued, and he stopped Dr. Magovern on his way out and told him he'd like to tackle the project.
"I said, 'Your boss said no, and he said, 'Well, I have a machine shop at home in my garage in Mt. Lebanon.'*"
That is how their partnership was formed, and over the next 20 years, Dr. Magovern estimated he put in more than 1,000 of the ball-and-cage valves.
Dr. Magovern said it took him only about three or four minutes to put the sutureless valve in place.
In the days when the science of cooling down the heart during open-heart surgery hadn't yet been refined, the much shorter installation time made a huge difference.
With the new valve, he said, he went from a 90 percent mortality rate to a 90 percent survival rate.
Mr. Cromie got a patent on the valve, and eventually, he went to work for Baxter Healthcare of Deerfield, Ill., which purchased the rights to the invention and is still one of the nation's leading artificial valve makers.
Dr. Magovern, who will turn 85 this year and whose sons took over the cardiac surgery department at Allegheny General after he left, said he wasn't particularly surprised to learn that his valve was still working in the Israeli man after 42 years.
A 25-year review of the ball-and-cage valve done in 1989 showed many of them were still functioning, he said, and recently, a patient he had operated on when the man was about 20 called him to let him know his valve was still working away after about 50 years.
A quick look at the statistics of the human heart shows how important it is to have reliable prosthetic valves. The heart beats about 80 times a minute, which means that over the course of a year, the heart's four valves open and close more than 42 million times. In an 80-year lifetime, they do their job more than 3 billion times.
Today, there are 80,000 to 90,000 artificial valve implants done every year, said Dr. Wolf Sapirstein, chief medical officer of the Division of Cardiovascular Devices of the U.S. Food and Drug Administration.
The ball-and-cage valve was eventually replaced by other kinds of designs, but metal valves still account for about a third of all heart valve surgeries.
The downside of metal valves is that they require patients to take blood thinners the rest of their lives to prevent clots that can form as blood rushes turbulently past the metal openings.
Because of that, valves made of animal and human tissue now dominate the prosthetic valve market, even though they tend to wear out after 10 or 15 years because of calcification.
The sutureless valve not only kept Dr. Magovern in his chosen field -- he estimates he did two valve surgeries a day, three days a week for more than 20 years -- but it played to his particular surgical strengths.
"I wouldn't say I was particularly skillful," he said from his winter home in Florida. "But I was fast."
