Risk of deterministic effects during endovascular aortic stent graft implantation

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 cm² (35-700 Gy cm²) 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.