Risk of deterministic effects during endovascular aortic stent graft implantation

Abstract

ABSTRACT. Since the 1990s, stent graft implantation for aortic pathology has become an alternative to extensive surgical procedures in some patients. Indeed, many patients with such pathology are now treated endovascularly. Only limited data concerning the risk of a deterministic effect during aortic stent graft implantation are available. Accordingly, 179 consecutive patients treated in our institute between October 2002 and July 2008 with endovascular aortic stent grafts were included in this study. Dosimetric data (kerma area product (KAP) and cumulative dose at the interventional reference point (CD irp )) from radiograph reports were analysed for 172 patients. On a group of 19 patients, GAFCHROMIC XR type dosimetric films were also used to verify the automatic measurements. Readings from the integrated KAP meter were found to be too high and were therefore corrected -KAP to dose area product (DAP) and CD irp to entrance skin dose (ESD). Median DAP was 153 Gy cm 2 (35-700 Gy cm 2 ) and median ESD was 0.44 Gy (0.12-2.73 Gy). Recorded dosimetric quantities were found to be good predictors of the skin dose and highlighted 4 patients (2.3%) who received skin doses that might cause possible deterministic effects. Endovascular stent graft implantation is less invasive than a surgical procedure and is widely used; mid-term results are encouraging. In a small number of patients, deterministic effects can occur even in departments with well-trained staff. Operators should inform the patients of possible skin injury after receiving high doses of ionising radiation and proper support must be available should that occur.

Endovascular Repair: Radiation Risks

“…Similar correlations were observed by Blaszak, et al (2009, and Kuhelj, et al (2010), but not by Pannucio (2011). found that the radiation burden is also influenced by the operative strategy chosen by the surgeon, that depends on the clinical presentation.…”

“…However, if concern is raised over skin dose, the radiochromic film can be removed from the bed during repair and examined by bare eye in normal light at the operation room for a rough dose assessment. Kuhelj, et al (2010) analyzing the dosimetric data on 179 patients treated using a suboptimal mobile C-arm unit found a 0.44 Gy median PSD (range 0.12 to 2.7 Gy). Investigators at Cabridge reported a 0.85 Gy median PSD on 96 repairs (Weerakkody, et al 2008;.…”

Radiation exposure during neurointerventional procedures in modern angiographic systems: A single center experience

“…Our estimated total mean peak skin dose was 0.489 Gy, while maximum and minimum values were: 1.78 Gy and 0.014 Gy. PSD allows us to determine the possibility for a patient to receive a radiation skin injury (10,23). Suggested threshold is 2 Gy (11,21,23).…”

“…Only 3 patients had PSD higher than 1.5 Gy and none of the skin injuries, like erythema were reported. Other studies showed that their estimated total mean PSD was 0.44 Gy, 1.01 Gy (21,23). Still, estimating PSD from KAP is problematic because during interventional procedures the X-ray tube is moved around the patient, thus irradiating different areas of skin.…”

“…The radiation dose parameter associated with the risk of stochastic effects is effective dose. KAP has been used to estimate both effective dose and peak skin dose in previous studies, although the conversion factors normally entail a degree of uncertainty or error (11,14,19,21,22,23). PSD was calculated from a published dose conversion formula for interventional procedures as follows: PSD (mGy) = 249 + 5.2 x KAP (Gy•cm 2 ) (21,24).…”