Monday, August 10, 2009


With the advent of interventional cardiology, and now also interventional radiology, more and more patients are exposure to radiation, both adults and also children. Paediatric Interventional Cardiology has grown by leaps and bounds, and many forms of congenital heart disease can be fixed by percutaneous interventional procedures. In many studies done, it is well documented that cardiologist and staff are usually well protected from excessive radiation exposure, but inadequate protection is often taken to protect the patient. I suppose, part of the reason would be that whereas staff are repeatedly exposed ( they work in the angiogram suite ), the patient may be there on a one off procedure. But it is common now for patients to have repeat procedure throughout their life, for example, PCI with in-stent restenosis. There are also those " normal checkup 64-MSCT angios " done annually for " heart checks ".
My interest in this subject was partly prompted by the widespread use of 64-MSCT and also when I saw that some intervetional radiological procedures, could take the whole day with 9 hours procedural time and 300-400mins of flouroscopy time. Some of my colleagues in Japan, when they do CTOs can sometimes take 5-6 hours to complete a complex PCI/CTO, giving the patient 200mins of flouroscopy radiation.
I think the subject of radiation disease should again be highlighted.
In the August issue of the Amnerican Journal of Roentgenology, Tsapaki V and colleagues published the paper " Radiation exposure to patients during interventional procedures in 20 countries: initial IAEA project results." The authors reviewed the radiation risk in 20 countries, mainly developing ones and found there in many countries, radiation doses to patients undergoing procedures were way in excess of acceptable limits, prompting their call that more attention and safe-guards for patients.
I suppose that it is true that most of us interventionist, never factored in the patient radiation risk, and we spend little time explaining to patient about them. Some of us have our own startegy that all pprocedures should not exceed 2 hours, because we will be too tired to think straight. A tired mind tend to make mistakes and also we are afraid of excessive radiation. However, some interventionist almost never gives up and go on and on, oblivious to the effect that they are harming themselves, their staff and their patient. This is made worse when they are intervening in disease subsects where the medical data is what we call a class 2 b indication ( the procedure done may have little benefit for the patient and only supported by clinical opinion of some experts ). It will be terrible practice, to take an assymptomatic CAD, discovered to have 3 vessel disease on 64-MSCT, into the angio suite, to try and do the 3V-CAD, spending 2-3 hours repairing complications and trying to cross a stable CTO. One wonders whether that procedure is good for the patient, the doctor or the staff, especially in the light of the " COURAGE trial" and many studies like that.
I only wish that the patients will always ask their doctor: 1. Is thia procedure necessary ( will it benefit me/patient )? and 2, what are the risk?, and in intevetional cardiology, what are the radiation risk. Not to forget that one 64-MSCT angio, is equivalent to a radiation exposure of one coronary angiogram, which is equivalent to the radiation exposure of 500 CXRays ( and that is only a fluoroscopy time of about 5-10mins. What then is the radation dose when you have a flouro time of 200mins??

No comments: