National Diagnostic Reference Levels for Endovascular Aneurysm Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection (ICRP) has highlighted the large number of medical specialties using fluoroscopy outside imaging departments without programmes of radiation protection (RP) for patients and staff. Vascular surgery is one of these specialties and endovascular aneurysm repair (EVAR) is one of the most challenging procedures requiring RP guidance and optimisation actions. The recent European Directive on Basic Safety Standards requires the use and regular update of diagnostic reference levels (DRL) for interventional procedures. The objective of the study was to know the doses of patients undergoing EVAR with mobile Xray systems and with hybrid rooms (fixed Xray systems), to obtain national DRLs and suggest optimisation actions. METHODS: The Spanish Chapter of Endovascular Surgery launched a national survey that involved hospitals for 10 autonomous communities representing the 77% of the Spanish population (46.7 million inhabitants). Patient dose values from mobile Xray systems were available from nine hospitals (sample of 165 EVAR procedures) and data from hybrid rooms, from seven hospitals, with dosimetric data from 123 procedures. The initial national DRLs have been obtained, as the third quartile of the median values from the different centres involved in the survey. RESULTS: The proposed national DRLs are 278 Gy cm2 for hybrid rooms and 87 Gy cm2 for mobile Xray systems, and for cumulative air kerma (cumulative AK) at the patient entrance reference point, 1403 mGy for hybrid rooms, and 292 mGy for mobile systems. CONCLUSION: An audit of patient doses for EVAR procedures to identify optimised imaging protocol strategies is needed. It is also appropriate to evaluate the diagnostic information required for EVAR procedures. The increase by a factor of 3.2 (for kerma area product) and 4.8 (for cumulative AK) in the DRLs needs to be justified when the procedures are performed in the hybrid rooms rather than with mobile Xray systems.

Preoperative mapping of the aortoiliac territory with duplex ultrasound in patients with peripheral arterial occlusive disease.

OBJECTIVE: Duplex ultrasound (DUS) arterial mapping of the aortoiliac area is limited by obesity, abdominal gas, and the need to use a low-frequency probe (and therefore poorer resolution) in the examination. The aim of this study was to analyze the degree of agreement between DUS mapping of the aortoiliac area and angiography or contrast-enhanced computed tomography angiography (CTA). METHODS: This was a retrospective observational study. Between November 2006 and June 2015, there were 173 patients with a surgical indication for aortoiliac occlusive disease included, with preoperative aortoiliac DUS mapping and subsequent CTA or intraoperative angiography. Sensitivity, specificity, positive predictive value, and negative predictive value of DUS as an arterial mapping test were analyzed, as was the degree of agreement with angiography/CTA and agreement between the surgical indication based on DUS and the final surgical technique performed. RESULTS: Of 173 DUS mapping tests, 155 were evaluated (89.6%); the remaining 18 were not able to be evaluated because of the patient's obesity or bowel gas. Overall accuracy of DUS for predicting significant artery lesions was as follows: 92% sensitivity (95% confidence interval [CI], 88%-95%), 96% specificity (95% CI, 95%-97%), 89% positive predictive value (95% CI, 86%-93%), and 97% negative predictive value (95% CI, 96%-98%). Agreement with angiography/CTA had a κ index of 0.81 (95% CI, 0.77-0.84), which reflects a good degree of agreement. Surgical indications based on DUS mapping were correct in 89% of cases (138/155). CONCLUSIONS: DUS mapping of the aortoiliac territory could be used as a single preoperative imaging test in aortoiliac occlusive disease in patients whose DUS examination is able to be evaluated.