Radiation Exposure in Endovascular Surgery According to Complexity: Protocol for a Prospective Observational Study.

In the past decades, we have witnessed tremendous developments in endovascular surgery. Nowadays, highly complex procedures are performed by minimally invasive means. A key point is equipment improvement. Modern C-arms provide advanced imaging capabilities, facilitating endovascular navigation with an adequate open surgical environment. Nevertheless, radiation exposure remains an issue of concern. This study aims to analyze radiation used during endovascular procedures according to complexity, comparing a mobile X-ray system with a hybrid room (fixed X-ray system). This is an observational and prospective study based on a cohort of non-randomized patients treated by endovascular procedures in a Vascular Surgery department using two imaging systems. The study is planned for a 3-year duration with a recruitment period of 30 months (beginning 20 July 2021) and a 1-month follow-up period for each patient. This is the first prospective study designed to describe the radiation dose according to the complexity of the procedure. Another strength of this study is that radiologic variables are obtained directly from the C-arm and no additional measurements are required for feasibility benefit. The results from this study will help us determine the level of radiation in different endovascular procedures, in view of their complexity.

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.

Endovascular Treatment of Descending Thoracic Aortic Pathology: Results of the Regis-TEVAR Study.

BACKGROUND: Endovascular techniques have become an essential tool for treatment of thoracic aortic pathology. The objective of this study was to analyze indications and results of thoracic endovascular aortic repair (TEVAR) in vascular surgery units, through a retrospective and multicentric national registry called Regis-TEVAR. METHODS: From 2012 to 2016, a total of 287 patients from 11 vascular surgery units, treated urgently and electively, were recruited consecutively. The primary variables analyzed are mortality, survival, and reintervention rate. The following indications for TEVAR were also analyzed: aortic dissections, thoracic aneurysms, traumatisms, and intramural hematomas or penetrating ulcers, as well as results and postoperative complications in accordance with each indication. RESULTS: Of the 287 TEVAR performed (239 men, mean age 64.1 ± 14.1 years), 155 were because of aortic aneurysm (54%), 90 because of type B aortic dissection (31.4%), 36 because of traumatic aortic rupture (12.5%), and 6 because of penetrating ulcers or intramural hematomas (2.1%). Overall mortality at 30 days was 11.5% (18.5% in urgent and 5.3% in elective), being higher in dissections (13.3%). The median actuarial survival was 73% at 4 years. The stroke rate was 3.1%, and the rate of spinal cord ischemia was 4.9%. Aortic reoperations were necessary in 23 patients (8.1%). CONCLUSIONS: This registry provides complete and reliable information on real clinical practice of TEVAR in Spain, with results similar to international series of open surgery. In accordance with these data, TEVAR can be performed with acceptable morbidity and mortality and with low rates of postoperative complications.

Contrast-Induced Nephropathy: A Fact or Fiction in Lower Limb Revascularization?

INTRODUCTION: Contrast-induced nephropathy (CIN) is defined as an increase >25% of serum creatinine from baseline, occurring in 24-48 hours after exposure to contrast, while alternative explanations for renal impairment have been excluded. The volume administered directly relates to risk, increasing by 12% per 100 mL of contrast. According to the series, its incidence varies between 3.3% and 8% in patients without renal damage and 12-50% in patients with chronic kidney disease (CKD) and/or diabetes mellitus (DM). The purpose of this study is to determine the incidence of CIN in endovascular revascularization of lower limbs in our center, where we apply the ALARA concept (As Low As Reasonably Achievable) to the use of contrast. MATERIAL AND METHODS: 163 patients who underwent endovascular revascularization procedures in lower limbs were included in this prospective observational study between February 2013 and April 2015. They were classified according to clinical stage and presence of DM and/or CKD. Data included serum creatinine values preoperative and postoperative, type and volume of contrast used. Patients on hemodialysis and those without sufficient analytical data were excluded. Chi-squared test and Student t-test were used for data analysis. P < 0.05 was considered statistically significant. RESULTS: 109 patients were enrolled, with 67% of DM and 31.5% of CKD. CIN incidence was 3.7% in patients without DM neither CKD, in DM was 6.8% and 12.5% in CKD. Mean creatinine presurgery was 97.96 and postsurgery 97.07, finding no significant differences between them (P = 0.753). Medium-contrast volume was 37.43 mL ± 22.3. The worsening variable (creatinine postsurgery minus creatinine presurgery) was evaluated according to clinical stage, DM, or CKD, being not significant in either group. CONCLUSIONS: In our experience, the dose administered of contrast was not related to the existence of postprocedure CIN, due to the policy of optimizing the use of contrast.