Study Detects Radiation-Induced DNA Damage in Operators Performing EVAR
November 8, 2017—A study that aimed to measure DNA damage/repair markers in operators performing endovascular aneurysm repair (EVAR) was published by Tamer El-Sayed, MD, et al online ahead of print in Circulation. The study's background is that radiation exposure during fluoroscopically guided interventions, such as EVAR, is a growing concern for operators.
In the study, expression of the DNA damage/repair marker, gamma-H2AX (γ-H2AX), and DNA damage response marker, phosphorylated ataxia telangiectasia mutated (pATM), were quantified in circulating lymphocytes in operators during the perioperative period of endovascular (infrarenal EVAR [IEVAR], branched EVAR [BEVAR], and fenestrated EVAR [FEVAR]) and open aortic repair using flow cytometry.
These markers were separately measured in the same operators but this time wearing leg lead shielding in addition to upper body protection and compared with those operating with unprotected legs. Susceptibility to radiation damage was determined by irradiating operators' blood in vitro.
As summarized in Circulation, levels of γ-H2AX and pATM were significantly increased in operators immediately after BEVAR/FEVAR (P < .0003 for both). Only pATM levels were increased after IEVAR (P < .04). Expression of both markers fell to baseline in operators after 24 hours (P < .003 for both). There was no change in γ-H2AX or pATM expression after open repair. Leg protection abrogated γ-H2AX and pATM response after BEVAR/FEVAR. The expression of γ-H2AX significantly varied when operators' blood was exposed to the same radiation dose in vitro (P < .0001), reported the investigators.
The study's conclusions stated that this is the first study to detect an acute DNA damage response in operators performing fluoroscopically guided aortic procedures; the study highlights the protective effect of leg shielding. Defining the relationship between this response and cancer risk may better inform safe levels of chronic low-dose radiation exposure, advised the investigators in Circulation.