Coronary angioplasty is a procedure to open narrowed or blocked coronary arteries.Usually the procedure is done via the transfemoral route.Though this route provides an easy vascular access,due to certain complications at the vascular site an alternative route has been experimented and has been successful.The complications of femoral access includes grion hematoma,may require blood transfusion, and even surgical repair.Compared to the transfemoral route,complications are very few in the transradial coronary angioplasty.
The Radial Approach
In the 80’s a French-Canadian physician named Dr.Lucien Campeau started using the radial artery for diagnostic catheterisations.By the 90’s scientists began to use the artery more intensively for interventional procedures for delivering balloons and stents.In the beginning a major setaback was the large size of the stents and catheters which made the use of the artery to a limited extent.but as time flew the advent of modern day stents and catheters made it much easier for doctors to use them and the artery became a site of choice for physicians and surgeons.
Before we approach the actual procedure there are a few pre-requisites for the patient to be a candidate for radial coronary angioplasty.The first criteria which is decisive for the operation is the presence of a dual or “protected” blood supply to the hand.The radial artery loops around the hand and joins the ulnar artery.Both the arteries supply to the hand and fingers.In case any damge happens and the radial supply gets shunted,the ulnar artery supplies blood and the damage is not felt at all.It is this dual supply which makes the radial approach so much popular among the doctors.The fig.below depicts a clear picture of radial and ulnar arteial supply.
The first test that a patients undergoes before the radial approach is the modified Allen’s test to verify a good collateral circulation by the ulnar artery.This test has to be positive for the operation to be conducted.In case the test is negative then the femoral approach is preferred.Patients with chronic renal impairment are sometimes avoided as there are some contraindications if the site is used.In addition the use of large devices during angioplasty,the presence of certain bypass grafts,and tortuous vessels which prevent the navigation from the arm to the coronary arteries are all setbacks for the radial approach.
Now lets move to the actual procedure.The wrist is sterilised,draped and hyperextended over an arm-board.The site is punctured after giving a local anesthetic.Along with other medications to sustain the patient, Heparin(anti-coagulant) is given to prevent any blood clots.A guide wire was passed though the puncture needle,the needle was removed, and a radial sheath was passed over the wire into the radial artery.Under fluoroscopic guidance catheters are advanced into the aortic root with a special guidewire.After the necessary procedures are done,the sheath is removed,hemostasis is acieved by a shory compression of the artery.If the patient is not heavily sedated he/she can walk from the operation table immediately.
The Merits and Demerits
- Even in obese patients the radial artery lies just beneath the skin and so it’s easy to manipulate.
- After the procedure, a short compression of the artery can bring about hemostasis.
- Even if there is any bleeding it can be seen immediately unlike in the femoral route where it goes unnoticed for a while.
- There is no major nerve near to the radial artery unlike te feoral nerve nearby the femoral artery,so the possibility of cutting a nerve is minimal.
- Complications are minimal.
- Patient can leave the operation table soon after the procedure.
- The patient does not have to spend long hours lying on the back,does not have to undergo the painful process of compression of artery to stop bleeding.
- Some patients even need not spend the night at the hospital if they are well enough.
- The cost of the process is much lower than the traditional method because of the reduced time at the hospital as well as the reduction of complications.
As with all medical procedures this also has its risks and therefore it must be explained to the patient beforehand.There are the restrictions of doing the process where tortuous vessels block the passage to the coronaries.