Monday, August 02, 2010

TRANSRADIAL PCI ( Percutaneous Coronary Intervention )

I was searching around to see what to highlight today, and this piece of news caught my attention. The Americans are beginning to wake up to transradial PCI. I just read an announcement that the Society for Coronary Angiography and Intervention is holding a summit and training program for transradial angiography in Boston in 5th Nov 2010. The faculty were mainly all Americans. I do not know why they do not want to bring over some Japanese or Dutch or French experts. Of course the Canadians are a no,no.
It has been traditional in many medical institution to teach PCI techniques via the transfemoral route. Before I proceed maybe it is bst to define what I mean. Transradial means to approach through the radial artery ( either right of left ) and transfemoral is to approach via the femoral artery ( either right or left ). In USA, the transfemoral approach is more popular as many of the hysicians were trained that way. Transradial approach is used in less then 10% of PCI procedures in USA. This is in stark contrast to elsewhere ( Europe and Asia ) where at least 50% of PCIs are done transradially. In fact, in some institution in Japan and China, 90% of PCIs are tarnsradial ( default transradial we call it ). That is also with us. In Malaysia, we are at least 50% transradial and with some operators, almost 90%.
I suppose an understanding of how we came this way is important. When Dr Mason Sones, first discovered coronary arteriography, he did it via a brachial artery cutdown. That was the way, when we began. A cutdown was a tedious procedure, isolating the brachial artery and securing access and then hemostasis. A good technique but took too much time, also more difficult to train and also has significant morbidity and complications.

Then came along Dr Melvin Judkins, who taught us that we could introduce tubes into artery safely, whith the use of percutaneous ( puncture through the skin ) technique. The Judkin's technique, as we call it, begins with a micro skin incision over the puncture site, a gentle puncture into the artery using a sharp needle ( either one piece or two piece ), and once the artery is properly punctured, a fine atraumatic guidewire is introduced, into the artery and over the guidewire, a sheath smaller then the artery size is introduced, and then the diagnostic and therapeutic cathers and devices are introduce.

Dr Melvin Judkins initiated the Judkin's technique for coronary arteriography via the femoral approach, as the femoral artery was big and easily felt and so easily punctured. All the cardiologist since the seventies were trained and master the art of percutaneous puncture of the femoral artery and did their angiograms and also teach their fellows to do the angiogram via the femoral artery puncture using the Judkin's technique. Soon the Sones's technique fell out of favour and many of us forgot how to do it. It was so cumbersome.

Then in the eighties, Dr Campeau ( Canadian ) and later Dr Kiemeneij ( Dutch ), began to promote the use of the radial artery for percutaneous angiogram and angioplasty. This radial artery catheterisation technique was actually first used by Dr Radner in 1948. Then the Japanese learned from the Dutch and we learned from the Japanese. For many of us, our teacher here was Dr Shigeru Saito, who taught us many things, including transradial angioplasty.

Having mastered it, we find that the transradial route was safer and more patient friendly. The bleeding issue was obviously less, being a smaller artery ( making nursing easier and less stressful for us ). There is a learning curve and initially we faced many issues, like radial artery spasm, difficulty in engaging the catheter especially in senior citizens, and occasionally, inability to puncture the radial artery.

Having done alot ( in the hundreds. I stopped counting after 500 ), I find that the cross over-rate ( unable to puncture and had to use the femoral artery route, at about 10% ). I also found that most Malaysians had good radial arch and the ulnar artery are usually large. and adequate. Our radial artery size ( I studied 20 samples when we first starte ) was about 2.5-3.0 mm in diameter, allowing us to use 6F and even 7F catheters.

There are more and more clinical trials coming out comparing the femoral route and the transradial route, and many came out in favour of the transradial route. The transradial route was proven to be safer, much less bleeding and more patient friendly. Patients can be ambulated after two hours of rest, and some patients can be discharged after 6 hours. So it can be cost saving too, especially in the USA. This bleeding problem is very important because, with all the new therapeutic regimes for unstable angina and coronary thrombus, many patients for cardiac interventions are on multiple anti-platelet agents, coupled with anti-thrombotic agents and maybe Glycoprotein 2B3A. One big bleeding millieu.
Perhaps, the biggest impediment to transradial catheterisation is " mind set". In our discipline, we cannot teach old dogs new tricks. Perhaps the Society for Coronary Angiogram and Intervention is taking on the task of trying to teach old dogs ( or not so old ones ), and some young dogs, new tricks ( old tricks for the rest of the world ). Perhaps Obama's healthcare reforms and cost cutting has something to do with this.
Welcome to my world.