A Lead Rectangle to Lower the Operator's Radiation Exposure

Overview

During fluoroscopic imaging, diagnostic information is carried in the primary beam. These high intensity X-rays are the chief hazard to the patient. Lower energy scattered radiation deviates in all directions from the patient. Despite typical precautions (i.e., hanging a lead shield between the patient and the operator), many operators will be exposed to high radiation dose (higher than the permitted 50 miliS per year), this long term radiation exposure may result in stochastic and deterministic effects. The purpose of this study was to test the hypothesis that a non disposable radiation protection drape (that will cover the lower part of the patient) could help minimize the radiation scattered from the patient to the operator. In a procedure done through the Radial approach, there is a large portion of the patients (from the umbilicus and down) that is a source of scatter radiation to the operator. This portion can be covered with a lead rectangle. A non disposable, lead drape of uniform thickness will be inserted into a sterile nylon bag and will be used during fluoroscopic and cineangiography coronary angioplasty procedures. The lead drapes will cover the femoral puncture site. The widths and length of the drape is 50-60cm and 100 cm respectively and was shown not to hinder the field of radiation needed for fluoroscopy and cineangiography. (The upper border of the lead is under the patient's umbilicus and was shown not to interfere with the radiation field needed for angiography or angioplasty). The Investigators anticipate that the study will show a significant reduction in radiation exposure and hence reduce the radiation hazard to the operator.

The Investigators tested the hypothesis on a Phantom that contain bones and tissue that simulate human tissue. The above phantom is used in the oncology department for testing radiation protocols delivered to patients. Those preliminary testing showed that a lead rectangle decreased significantly the radiation scattered towards the operators and personnel in the catheterization laboratory. In all chosen places whether 40 or 100 cm from the radiation beam - The Investigators detected a significant reduction in scattered radiation. The significant reduction in these experiments is attributed to the location the Investigators choose but also to the size of the lead drape 100 X60 cm which give a large area of protection. From simple geometric calculations it's understandable that the zone or volume of radiation protection become much larger further away from the lead rectangle.Patients who are admitted for an elective PCI procedure ( or stable ACS patients) will be ask to participate in the study and sign an informed consent. All the procedure will be as standard of care, after cleaning the right or left arm, and the groin a sterile towel will cover the groin, on top of the sterile towel the lead rectangle (that by itself will be inserted to a sterile nylon bag) will be put over to cover the area from the umbilicus and down. (In case that the radial approach will fail and femoral approach will be needed, it is easy to remove the lead rectangle while keeping sterile field in the groin area). Few dosimeters will be used to assess radiation exposure, two underneath the lead apron, one on top, and two dosimeters for the operator (two detecting the radiation exposure in the neck area). The Investigators will approach patients in whom a long procedure time and higher radiation exposure are anticipated (like patients with chronic total occlusion, heavily calcified or tortuous coronary arteries). In those, the fluoroscopy time on average, is longer than usual. A total of 50 patients will be recruited (based on the Investigators preliminary radiation testing on the phantom and the results of Politi et al). In 25 patients a lead rectangle will be used on top of the regular protection (personal lead suit, leaded glass shield), in 25 patients only regular protection for the operators.