The embolectomy balloon catheter is the quintessential tool of the interventional cardiologist. Today, there are many variations on the basic design: they can be used to dilate or occlude vessels, for dissection or anatomical development of planes or to deploy stents, for example. Interventionalists are finding new ways all the time to use them in the vasculature throughout the body. Today's interventional cardiologist owes a big debt of gratitude to the inventor of the balloon catheter, Dr Thomas Fogarty, and in particular to his interest in ships in bottles.
The story of the Fogarty embolectomy catheter starts in the 1950s. Fogarty recalls: "When I was very young I worked in a hospital as an orderly and then I made my way up to being a scrub technician - where you hand instruments to the surgeon during an operation. I saw a lot of surgery at a very young age, and I also saw what did and didn't work. What was not working, very clearly, was the attempt to remove thrombus from the artery/veins."
Clots in the blood vessels are serious and in the 1950s the standard invasive and lengthy surgical procedure was not able to cope, with amputation an all-too frequent result. Fogarty's mentor at the time, Jack Cranley, challenged him to make something better. Fogarty took the challenge home and developed the catheter. "It was one of those things that went like a light bulb. Often things don't come that way but this one did," says Fogarty.
From Foley to Fogarty
Catheterisation is not a new procedure. The ancient Egyptians are reported to have used papyrus to form tubes to drain fluids from the body, while the Greeks used reeds for similar purposes. Furthermore, Fogarty's balloon catheter was not the first medical catheter to use a balloon. The Foley catheter is a flexible tube with a balloon at the tip that is passed through the urethra into the bladder to drain urine. Filling the balloon with sterile water holds it in place. Despite the fact that the Foley catheter predates Fogarty's by around 20 years, it cannot claim to be the first therapeutic catheter; that accolade definitely rests with Fogarty.
Neither was the Foley the inspiration for Fogarty. "What gave me the inspiration was a pretty simple concept. If you take a bottle with a narrow neck you can push an elastomeric balloon inside (if you make it lubricious). This came from ships in a bottle; I was thinking about how you could get something bigger than the neck of the bottle into the bottle."
The Fogarty catheter was first used in the peripheral arteries of a live patient in the early 1960s, with Fogarty acting as the scrub technician. It was patented in 1963, although its impact was not realised at first - not even by Fogarty himself.
In fact, the first paper detailing the invention of the balloon catheter appeared in Surgery, Gynaecology and Obstetrics, published in a very small section at the end of the journal called Surgeon at Work. Prior to that, it was turned down by four major journals: Surgery, Archives of Surgery, the Journal of the American Medical Association and Annals of Surgery.
The problem was the prevailing sentiment in surgical circles: "Most surgeons my age and even a lot younger were taught the craft of surgery saying 'the bigger the incision the better the surgeon'," Fogarty observes. So a new device that does its duty through an incision an inch wide at most was clearly not proper surgery.
Fogarty faced difficulties with his catheter at university too. This was despite the fact that he was studying at the University of Oregon, where he met the man nowadays considered to be the father of interventional radiology, Charles Dotter. Dotter, together with Melvin Judkins, first described angioplasty in 1964 - using a balloonless catheter. Fogarty explains: "What they were dong at that time was just trying to put bigger and bigger catheters in. They would take a small catheter, get past the opening then pass over that small catheter a larger catheter; they would keep doing it until they got to the right size. It worked sometimes, but it was very traumatic and often caused injury or burst a vessel. My concept was rather than make a hole bigger and bigger, both in the skin and the artery, let's get it in skinny, make it bigger inside and then dilate."
Fogarty continues: "Dotter knew I had developed the balloon catheter, and he had always felt that you could do much more with a catheter than just make a diagnosis. So he approached me to help him with some of his procedures, which I did just because I was interested." However, at that time Fogarty was a surgery resident, and the chief of surgery heard about him making balloons for Dotter. "At that time surgeons thought that everything associated with using catheters to do a therapy was absolutely crazy. My boss told me that if I was interested in surgery and with continuing with my residency, I could not associate with Dr Dotter."
Thus Fogarty went underground. "I continued to make catheters for Dotter, and at night I would go and help him use them." The crucial development at this stage was to make the balloon a fixed volume rather than having a variable volume that could just keep on expanding. However, the modern materials needed to make a thin-walled strong balloon were not available, so Fogarty simply doubled the thickness of the elastomer. "In other words I put two balloons on - and that is what we did the first dilatation with. When you use a fixed-volume balloon you can actually break the plaque and gradually displace it."
Into the Heart
The irony is that while surgery was struggling to help people with thrombus and at risk of losing a limb, the surgeons themselves were resistant to this new way of treating it. "Sewing was what surgeons were trained to do. Doing anything other than sewing was very foreign to them and interpreted as being foolhardy and dangerous," Fogarty observes. "The ones who adopted the balloon catheter were the cardiologists."
The Fogarty catheter, and Fogarty himself, have played founding roles in the development of interventional cardiology. By adopting the new technology and adapting the new techniques, cardiologists created their own tools for treating blockages in the coronaries and beyond. "Now I think the distinctions between a cardiologist, a cardiac surgeon and an interventional radiologist are getting blurred. A cardiologist can do a dilatation, a radiologist can do it and a surgeon can do it. It used to be totally speciality related - but soon it will reach a point where there won't be much of a distinction between interventionalists who treat the vascular and cardiac systems."
Fogarty himself is surprised by the way his catheter has developed. "I am very proud of it; a lot of it I did not predict. It is like many things: you provide a tool and people learn to use it in different ways. That happens to a lot of technologies."
There are other developments in interventional cardiology that have complemented the embolectomy catheter, for instance John Simpson's atherocath to remove plaque percutaneously rather than displacing it was "a significant contribution", Fogarty notes. And, of course, no paper on interventional cardiology would be complete without a mention of stents. "As far as I can tell that was a pure contribution of the cardiologists. I don't think surgeons were really looking at stents as stents. They were looking at them as connectors but not as something that would maintain a lumen."
The Fogarty embolectomy catheter helped take interventional medicine from large, risky, open procedures to minimally invasive, safer and smaller operations. The next step along that path is to prevention. However, "Nobody pays for prevention," Fogarty comments. "They should but they don't, and if you are not going to get paid for something then you are not going to do it very often - you cannot afford to."
For his part, Fogarty is still inventing and has expanded his entrepreneurial interests, founding or co-founding more than 30 start-up companies that manufacture medical devices, as well as co-founding Three Arch Partners, a venture capital firm. But his cardiovascular interests extend beyond developing devices and techniques, and he also owns and runs Fogarty Wines. "The relationship between alcohol intake and lack of atherosclerosis is something I observed very early in my career." Of course, while alcoholics may have very little atherosclerosis, they usually die of something equally as bad, such as cirrhosis, but small amounts of alcohol can be beneficial. "I didn't go into the wine business for that reason, but it turned out fortuitously because wine is really a very inexpensive and great tasting preventative medicine."
The growth of interventional cardiology is a great story of innovation and invention triumphing over established ideas and dogmatic views. The pioneers of interventional medicine were those people who looked at what was being done and wondered how it could be done better - and no-one typifies this more than Fogarty. It is difficult to predict for how much longer the balloon catheter will continue to be the 'industry standard', but what is sure is that it has played a huge role in the paradigm shift in 20th century medicine that is continuing in this century. And Fogarty has one more message for the cardiology community, "Tell them to prescribe Fogarty wine."