Fig. 10.1
Difference between two puncture kit. Bare needle (Cordis, co U.S), Plastic cannular (Terumo, Japan)
Fig. 10.2
(a) Characteristics of Single wall puncture: Only front wall being punctured, needle needs to be directed more coaxial to the vessel course (point to point), thus the successful rate at first attempt is less. There is Less pulsatile blood flow coming out after artery is punctured; The wire has diameters of 0.021 cm, non-coating with less support; The stiff tip is more easily to penetrate though the vessel wall to the surrounding tissue. Need make a skin incision with scalpel routinely before sheath insertion. (b) Characteristics of double wall puncture: Both front wall and counter wall being punctured (point to line), thus the successful rate at first attempt is higher. There is more prominent pulsatile blood flow coming out the hub after artery being punctured; Less chance of getting success while a hematoma formed after an unsuccessful attempt; The wire has diameters of 0.025 cm and coated, thus has chances of dissection by inadvertent advance; does not need make a skin incision with scalpel routinely for sheath insertion
Two puncture kits (Bare needle and plastic cannula) are most commonly used for TRA. Both puncture technique can obtain high rate of success at experienced hand, although majority of beginners prefer to use Terumo puncture kit due to its shorter learning curve. However, to some extent, one technique has advantage over the other, thus understanding both two puncture techniques are necessary.
Bare needle | Plastic cannula | |
|---|---|---|
Components | 21G needle 25 cm 0.021″wire 11 cm sheath (Cordis U.S) | 20G needle 45 cm 0.025” wire 16 cm sheath (Terumo Japan) |
Method | Single wall puncture Point to point | Counter wall puncture Point to line |
Successful rate at 1st entry | Lower | Higher` |
Need for skin incision | Yes | No |
Penetrating the vessel wall | More frequent | Less frequent |
Suitable for small/fine vessels | +++ | + |
Useful for multiple punctures | +++ | + |
Vessel spasm | More frequent | Less frequent |
See also Chap. 4
Question 2: What should be done in case of first puncture failure?
Attempt at a successful puncture at first hit. However, if the first puncture fails, do not completely remove the needle, keep the needle in situ. Next, feel the radial pulse followed by reassessing the direction for re-inserting the needle. In case the current position of the needle is too far from the radial pulse, remove the needle completely and choose a more suitable position for re-inserting the needle. Sometimes, upon increased pressure of the left fingers on the radial artery while checking for pulse, the blood flow could be tampered and leads to the puncture failure. Then relieve the pressure slowly to re-instate the blood flow and repeat the puncture at the suitable site. In case of puncture failure by the plastic cannula (Terumo kit), switch to the bare needle to increase the likelihood of successful puncture, this is especially useful in case of small sized vessel and multiple punctures (Figs. 10.3 and 10.4).
Fig. 10.3
Redirect the needle if the first attempt failed by defining the appropriate relationship between the position of needle and radial pulse
Fig. 10.4
Avoid excess pressure as radial artery can be easily occluded by finger pressure
Question 3: How to ensure higher success rate of first puncture?
(1) Check radial pulse carefully; Perform a radial/ulnar ultrasound if the radial pulse is weak. (2) Positon the forearm flat to fully extend the wrist. (3) Analgesics or Lidocaine should be given to ensure patient’s comfort and decrease the chance of vessel spasm. (4) Chose a proper site for puncture, Normally 1 cm above the radial styloid process. However, if the artery is tortuous or has puncture previously; puncture site should be slightly proximal to the tortuous segment to increase the success rate (Fig. 10.5). (5) The Angle of puncture is 30—45°. However, the angle should be adjusted according to the anatomical differences per patient. The angle should be smaller for thinner patients when the pulse is superficial and fine to increase the likelihood of successful puncture. The angle should be larger for obese patents when the pulse is deep (Fig. 10.6).
Fig. 10.5
Increase the successful rate for tortuous radial artery : choose more proximal puncture site, avoid access at radial styloid process, feel the relationship between the need and radial pulse properly, slowly advance
Fig. 10.6
Angle need to be adjusted according to variety of situation. The angle should be smaller for thinner patients when the pulse is superficial and fine. The angle should be larger for obese patents when the pulse is deeper
Question 4: Is the use of anti-spasm required routinely?
Anti-spasm therapy includes lidocaine, nitroglycerin and verapamil, however, in a higher volume center with highly experienced interventionists and highly likelihood of first chance puncture, the cocktail administration may be neglected since administration of lidocaine can lead to patient discomfort.
Question 5: What should be done if the wire meets resistance after a successful puncture?
Even in the presence of blood flow after a successful puncture, sometime the wire can encounter resistance. This could be due to the wire entering smaller branches or the vessel being tortuous and could also be due to vessel spasm. The wire may enter the medial layer causing dissection or penetrate the vessel wall, in this situation, do not further advance the sheath. Perform a fluoroscopy of the arm and adjust the wire. If the sheath is already inserted and blood flow is not present, withdraw the sheath slightly until the blood flow returns. If the blood flow does not return, remove the sheath and apply pressure to the puncture site.
Question 6: How to effectively treat forearm hematoma?
The most effective way in treating forearm hematoma is not by surrounding the forearm with pressure bandages, elevation of the elbow or use of ice for decreasing the swelling but focus on identifying the bleeding site and performing manual compression on bleeding site for 30 min to 1 h until the tension is released, followed by covering with pressure bandages. Normally the accurate site of bleeding is where the patient feels the most pain (Figs. 10.7 and 10.8).
Fig. 10.7
The most effective thing to treat forearm hematoma: identifying the bleeding site within 10 min, manual compression until the tension is released,, then covering it with pressure bandage
