Catheterization introduces a small tube into a blood vessel. The tube is then guided to the internal organ needing intervention. Often, the arteries of the heart are repaired (coronary arteries). Access is usually by arteries located close to the skin in the wrist (radial or ulnar arteries) or the groin (femoral artery).
The wrist (radial) artery is becoming the preferred access point for PCI (Percutaneous Coronary Intervention) by interventional cardiologists. A larger, shorter, hollow tube (sheath) is inserted first to serve as an "introducer" for wires and catheters.
Fluoroscopy (X-ray video) guides the procedure. Interventional Cardiologists and their assistants are exposed to more scatter radiation than any other medical profession.
The staff wear heavy, lead-containing garments, caps, and eyeglasses for protection. Also, leaded shields are located above and below the catheterization table. Full protection for the head and arms is rare, though, since freedom of movement is necessary for the procedure. The most neglected scatter radiation zone, then, is between the patient's trunk (torso) and the staff's arms and heads.
Scatter Radiation Effects and Protection -- Introduction
How the Cardio-TRAP fits into Cath Lab procedures:
Left Radial Base ------
Base Board ------
------ Right Radial Base
------ Left Arm Board
• Base board (BB) - The BB is the foundation for attachment of all components. The BB remains with the table and is never to be moved between rooms. It attaches to the top of any cath table with two 2" wide Velcro strips and can be removed for occasional cleaning. Never use a Base Board that isn't secured to the table with Velcro. The BB does not interfere with image quality.
***Always remove all Cardio-TRAP components from the BB before loading the patient***
• Sterile field/draping - The removable, non-sterile components of the Cardio-TRAP are installed after the patient is placed on the table. Sterile sheets are then draped over the patient and the Cardio-TRAP. The Cardio-TRAP can be safely wiped down with any sterilizing chemical used in the industry.
• Shielding - The Cardio-TRAP shield (the only radiation absorber) covers much of the scatter radiation source (the patient). The shield attaches to the base board between the patient's trunk and right arm and contains a sheet of lead 1mm thick. The shield's location is adjustable to allow for patient size and physician comfort during radial or femoral access. Both the Standard or Femoral shield have been used by many physicians as an arm rest during femoral access. The shields are 32 inches long and the Radial Shields are 10 1/2 inches
tall, measured from the top of the BB. In addition to providing superior radiation protection,
the shields also prevent femoral site contamination caused by patient groping. A patient may become disoriented and confused during the procedure. When this happens during a femoral access case the patient may try to reach for the femoral access site. The shield blocks the patient's hand and stops the patient from contaminating the sterile field.
a. Standard (radial) - This shield will work with any cath
table. The lower right area is cut out to accomodate any style of
mattress. [All of our radiation surveys and dosimeter
comparisons were completed using the Standard Radial Shield.]
b. Femoral Shield - The Standard Femoral Shield is a
Standard Radial Shield cut out to put the physician's hands closer
to the femoral site, but povides about 20% less shielding than
the Standard Radial Shield. The Full Femoral Shield (shown)
has more than 20% more shielding than the standard femoral
c. Full Shield - The Full Shield is available in either
Radial or Femoral style. Many mattress pads do not interfere
with the shield, so the lower right area can add to the maximum
protection from scatter radiation. The Full Shield provides about
20% more protection than the Standard Shields.
• Right Radial Base (RRB) - The RRB provides an extended, elevated work surface that is ideal for right radial access. It is 45 inches long and 14 inches wide. The extra space provides support for the staff and the instruments used in the procedure. Scrub Technicians and Interventional Cardiologists highly value the extra space that the RRB provides.
The RRB also holds the physician and scrub technician at a safer distance away from the scatter radiation source (the patient). Consistent use of either Radial Shield (Standard or Full) with the RRB will result in an average dosimeter number reduction of at least 40-50%. The RRB contains no lead and does not interfere with the x-ray image.
The RRB work surface is elevated 2 inches above the level of the BB. This feature allows:
a. More comfort for the patient.
b. An extended work surface that doesn't interfere with table controls.
c. Reduced exposure. Depending on staff experience, radial procedures may cause more scatter radiation exposure than femoral procedures. Because most radial cases are performed on a "board" that is slipped between the cath table and mattress, the scatter radiation source (the patient) is closer to the physician's head than in femoral cases. By elevating the right radial access site 2 inches, the scatter radiation source is 2 inches further away from the physician's head and eyes.
• Left radial base (LRB) - Patients who have had bypass surgery
usually have their radial heart catheterizations performed via the
left wrist. Very few cardiologists choose to perform a left radial
access procedure on the left side of the table, since they practice
mostly on the right side of the table. Also, changing a procedure
from right side table operation to left side table operation requires
turning around the room set up. All table controls, screens, and
wheeled lab equipment must be moved. This can take two people
15 minutes. During an urgent situation, turning the room around
Prior to the development of the Left Radial Base, it was common
practice to stuff pillows or towels under the patient's left arm to
support the arm, allowing access from the right side of the table.
The LRB actually was developed after a stack of towels collapsed
during a procedure. The patient's arm fell to the side of the table,
pulling a wire out as it slid across the patient's chest.
• Left arm board (LAB) - The Left arm board has two uses. First,
for gaining left radial access on the left side of the table before the left arm is crossed over the patient's torso to work from the right. Second, the LAB can be laid on the head end of the Right Radial Base, under the patient's arm, for those cardiologists that prefer to start or perform the procedure with the patient's right arm at some angle away from the torso.
Attaching/Detaching removable components of the Cardio-TRAP:
(choose full screen)
Installing the Base Board: