Cabin protects head, feet from radiation during device extractions

A cabin that shields operators during cardiac device extractions drastically cut radiation to their heads and feet without requiring heavy lead aprons, according to a study published in the December issue of the Canadian Journal of Cardiology.

Extracting transvenous lead systems in patients with implanted cardiac devices can be a complex and lengthy procedure that exposes operators to rays scattered off the patients’ body. Physicians can wear lead aprons, thyroid collars and leaded glasses to protect themselves from radiation but the aprons are heavy and cause fatigue and back problems, and the use of other gear is sometimes low.

Sylvain Ploux, MD, of the University Hospital of Bordeaux in France, and colleagues evaluated the use of a full-body radioprotective cabin, the Cathpax CRM, supplied for free by Lemer Pax for the study. The cabin can accommodate two people and gives physicians access to the patient through arm holes. For this study, the cabin was open during prefluoroscopic preparations, surgery and wound closure and the upper portion was closed during lead extraction.

They enrolled 37 consecutive patients who needed extraction of single-, dual- and triple-chamber pacemakers or implantable cardioverter-defibrillators. The control group (19 patients) received standard extraction techniques with operators protected by lead aprons, thyroid collars and leaded eyeglasses. The other 18 patients were treated by physicians using the radioprotective cabin.

All operators wore dosimeters on their back, left foot, thorax and neck. In the control group, they wore dosimeters on the back and thorax under their aprons.

Procedure times and fluoroscopy exposure times were similar between groups. All procedures were successful, with complete extraction rates of 78 percent and 84 percent in the cabin and control groups, respectively. Five patients needed femoral extraction to complete the procedure. There were no deaths from intra- or periprocedural complications and no major complications.

The mean dose of radiation to operators was similar for the thorax and back for both groups. But exposure to the head and feet was much lower for the cabin group, at 0.04 vs. 2.72 mSv/min for the head and 0.03 and 11.73 mSv/min for the feet.

“The exposure of the head and the feet were respectively 68 and 390 times less in the cabin group than in the control group,” Ploux et al wrote. “This greater exposure of the feet confirms that the secondary x-rays (scattering) from the patient’s body make a much larger contribution to exposure of the operator than the primary radiation originating from the x-ray tube.”

They pointed out that the cabin didn’t interfere with femoral extractions. Based on that success, they proposed the cabin also might be used to protect cardiologists during ablation, coronary angiography and revascularization procedures.  

Read “When Rad is Bad: Reducing Cath Lab Operator’s Exposure Risk” for more radiation-reduction approaches.