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Even fairly straightforward endovascular lower-extremity interventions can result in high radiation exposure that rivals doses associated with coronary interventions, according to research published online July 24, 2013, ahead of print in the Journal of Vascular Surgery. According to the study, pelvic procedures impart the highest dose.

Radiation exposure during 346 therapeutic lower-extremity interventions was retrospectively estimated by Ido Weinberg, MD, of Massachusetts General Hospital (Boston, MA), and colleagues. All procedures were performed at Hadassah Hebrew University Medical Center (Jerusalem, Israel) between September 2006 and December 2011. Radiation parameters assessed were dose area product and fluoroscopy time. In addition, data were collected on patient demographics, procedure indication, procedural access, and anatomic location of occlusive disease, classified as pelvis, thigh, below the knee, or multilevel (thigh and below the knee but not pelvis).

Pelvic Procedures Worst Offenders

Overall, median dose area product was substantial. In particular, values for pelvic procedures were higher than those for thigh or below-the-knee interventions despite shorter fluoroscopy times (both P < 0.0001; table 1).

Table 1. Dose Area Product and Fluoroscopy Time, by Intervention

Procedure access site also affected radiation dose, with contralateral up-and-over access resulting in a higher dose area product than antegrade access (112.2 Gy/cm² vs. 42.6 Gy/cm²; P < 0.0001). However, in multivariable analysis, anatomic location of the procedure showed the strongest association with radiation dose (P < 0.0001).

Location, Location, Location

In a telephone interview, Dr. Weinberg told TCTMD that “when you compare the radiation dose in a standard low extremity procedure that can take an hour, hour-and-a-half, the average amount of radiation that these procedures involve is right on the higher end of any cardiac procedure that you can imagine. In fact, the average dose is on the verge of the limit that is allowed for skin injuries.”

Another surprise, he said, was that the shorter and technically simpler procedures involving the iliac arteries actually imparted the most radiation. “It’s the anatomy that counts and not always the complexity or the time the procedure takes,” Dr. Weinberg observed. “Iliac procedures are very simple to do—they could take 10 minutes—but those are the procedures that involve the most radiation.”

But Stephen Balter, PhD, of Columbia University Medical Center (New York, NY), told TCTMD in a telephone interview that the findings are not surprising since they have been previously reported in the literature. “The basic story,” he said, “is that the contralateral retrograde requires more radiation than the antegrade. This always happens because these are harder procedures. The extra dose simply represents that the operator has to do more work.”

Caution Called For

“ALARA [As Low As Reasonably Achievable radiation dose] is very relevant for these procedures,” Dr. Weinberg said. “Not paying attention to that could result in great radiation exposures, especially for physicians who perform or patients who undergo these procedures often.”

Of course, the amount of radiation exposure should not be the deciding factor for whether or not a patient receives an intervention, Dr. Balter said. Nonetheless, he added,” the same way that we won’t expose a patient to an unnecessary CT scan or we will inform a patient prior to a study that it will involve radiation, I think the same kind of package should be involved with these procedures as well.”

Dr. Balter said he is less concerned about the radiation exposure associated with PAD simply because such patients tend to be older and are therefore unlikely to develop the late cancers associated with such exposure. Moreover, “given the present level of technology, I don’t see how [physicians] can do this work with much less radiation,” he added.

Directions for Future Research

This single-center study should be repeated in a multicenter analysis, Dr. Weinberg said. He also advocated research to estimate lifetime radiation doses received by PAD patients, since they typically undergo a number of exams and procedures involving radiation exposure. Another area that deserves exploration, he said, is the radiation exposure of interventionalists who regularly perform lower-extremity procedures.

Source:

Segal E, Weinberg I, Leichter I, et al. Patient radiation exposure during percutaneous endovascular revascularization of the lower extremity. J Vasc Surg. 2013;Epub ahead of print.

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