Editor's Choice - Minimizing Radiation Exposure During Endovascular Procedures: Basic Knowledge, Literature Review, and Reporting Standards.

CONTEXT: Endovascular procedures, requiring X-ray guidance, are commonly performed in vascular surgery. X-ray exposure is associated with biological risks for both patients and physicians. Medical X-ray use must follow "as low as reasonably achievable" (ALARA) principles, which aim at using the lowest radiation exposure to achieve a procedure safely. This is underlined by European and international recommendations that also suggest that adequate theoretical and practical training is mandatory during the initial education of physicians. However, the content of this education and professional practices vary widely from one country to another. OBJECTIVE: This review aims to summarize the basic knowledge required for vascular surgeons on X-ray physics and image production. METHODS: A panel of endovascular therapists (vascular surgeons and radiologists) and physicists dedicated to X-rays was gathered. International recommendations were summarized. A literature review was performed via MEDLINE to identify studies reporting dosages of common endovascular procedures. RESULTS: The different mechanisms inducing biological risks, and the associated potential effects on health, are described. Details on dose metrics are provided and a common nomenclature to measure, estimate, and report dose is proposed in order to perform accurate comparisons between publications and practices. Key points of the European and international legislation regarding medical X-ray use are summarized, and radiation protection basics for patients and staff, are detailed. Finally, a literature review is proposed for physicians to evaluate their practice. CONCLUSIONS: Today's trainees will be highly exposed to radiation throughout their practice. It is thus compulsory that they undergo dedicated radiation education during their initial training, and regular refresher sessions later. In daily practice, focus on dose reduction and monitoring of patient and staff exposure are mandatory.

Impact of hybrid rooms with image fusion on radiation exposure during endovascular aortic repair.

OBJECTIVE: To evaluate exposure to radiation during endovascular aneurysm repair (EVAR) performed with intraoperative guidance by preoperative computed tomographic angiogram fusion. METHODS: All consecutive patients who underwent standard bifurcated (BIF) or thoracic (THO), and complex fenestrated (FEN) or branched (BR) EVAR were prospectively enrolled. Indirect dose-area product (DAP), fluoroscopy time (FT), and contrast medium volume were recorded. These data were compared with a previously published prospective EVAR cohort of 301 patients and to other literature. Direct DAP and peak skin dose were measured with radiochromic films. Results are expressed as median (interquartile range). RESULTS: From December 2012 to July 2013, 102 patients underwent standard (56.8%) or complex (43.2%) EVAR. The indirect DAP (Gy.cm(2)) was as follows: BIF 12.2 (8.7-19.9); THO 26.0 (11.9-34.9); FEN 43.7 (24.7-57.5); and BR 47.4 (37.2-108.2). The FT (min) was as follows: BIF 10.6 (9.1-14.7); THO 8.9 (6.0-10.5); FEN 30.7 (20.2-40.5); and BR 39.5 (34.8-51.6). The contrast medium volume (mL) was as follows: BIF 59.0 (50.0-75.0); THO 80.0 (50.0-100.0); FEN 105.0 (70.0-136.0); and BR 120.0 (100.0-170.0). When compared with a previous cohort, there was a significant reduction in DAP during BIF, FEN, and BR procedures, and a significant reduction of iodinated contrast volume during FEN and BR procedures. There was also a significant reduction in DAP during BIF procedures when compared with the literature (p < .01). DAP measurement on radiochromic films was strongly correlated with indirect DAP values (r(2) = .93). CONCLUSION: The exposure of patients and operators to radiation is significantly reduced by routine use of image fusion during standard and complex EVAR.

Endograft repair of complicated acute type B aortic dissections.

OBJECTIVES: This study aims to assess patient outcomes and aortic remodelling following coverage of the proximal entry tear with an endograft in complicated acute type B aortic dissections (caTBADs). MATERIAL AND METHODS: All patients with caTBAD treated with a thoracic endograft in three high-volume vascular centres were retrospectively studied. Inclusion criteria were branch-vessel malperfusion, impending or overt aortic rupture, maximal aortic diameter ≥ 40 mm and persistent pain or uncontrolled hypertension despite maximum pharmacological treatment. Postoperative aortic remodelling was evaluated using computed tomography angiography (CTA) on a three-dimensional (3D) imaging workstation. RESULTS: A total of 52 patients (71% male, median age 65 years) were included in the study. Median inclusion criteria per patient were 2 (range 1-4). Branch-vessel malperfusion was diagnosed in 42% and impending aortic rupture in 33% of 52 patients. Median follow-up was 25 months (range 2-109 months). The 30-day mortality rate was 9.6% (5/52); patient survival according to the Kaplan-Meier method was 90.4% at 12 months and 87.6% at 24 months. Secondary interventions were performed in seven patients a median of 3 days after the initial procedure (range 2-865). Imaging follow-up at 12 months was performed in 36 patients (69%): 75% presented stable or shrinking (> 5 mm) maximal aortic diameters and 86% had a completely thrombosed false lumen (vs. 5% before initial procedure) at thoracic level. CONCLUSION: Endograft treatment of complicated caTBAD is associated with favourable early outcomes and possibly promotes aortic remodelling in the majority of patients.

The benefits of EVAR planning using a 3D workstation.

OBJECTIVES: To evaluate the influence of planning endovascular aneurysm repair (EVAR) with a three-dimensional (3D) workstation on early and midterm outcomes. METHODS: All patients undergoing infrarenal EVAR performed between 2006 and 2009 at our institution were included in the current study. Prior to 2008 (group 1), endograft sizing was performed by interrogation of computed tomography angiography axial images. After 2008 (group 2), endograft sizing was routinely performed using a 3D workstation (Aquarius, Terarecon), allowing for multiplanar reconstruction and centerline analysis. Pre-, peri-, postoperative, and follow-up data were prospectively entered in an electronic database. All postoperative complications and subsequent secondary interventions depicted during the 2-year period following EVAR were compared. Secondary intervention and mortality rates were defined at 2 years and compared. Freedom from secondary intervention and overall survival rates were calculated using the Kaplan-Meier method during follow-up and compared by log-rank test. RESULTS: A total of 295 patients (149 patients in group 1 and 146 patients in group 2) were included. All patients had completed a minimum of 2 years of follow-up. During this 2-year period following EVAR, the type 1 endoleak rate was 8.7% in group 1 and 1.4% in group 2 (p = .004) respectively. Secondary intervention rates related to type 1 endoleak was 5.4% in group 1 and 0 in group 2 (p < .001). No difference was observed regarding all-cause mortality, aneurysm-related death, and freedom from secondary intervention rates during follow-up. CONCLUSION: The routine use of 3D workstations for EVAR planning significantly reduces the rate of type 1 endoleaks and, therefore, the rate of related secondary interventions.

Aortic dissection and malperfusion syndrome: a when, what and how-to guide.

Malperfusion syndrome is a complication of aortic dissection caused by branch-vessel involvement and resulting in end-organ ischaemic dysfunction. Clinical diagnosis is mandatory, and imaging plays a critical role in confirmation and treatment planning. Radiologists must focus on detecting complications (findings of aortic dilation, rupture, organ ischaemia, etc.) and defining vascular compromise and associated malperfusion mechanisms. All these factors guide the multidisciplinary discussion concerning patient management and the suitability of endovascular treatment. Application of dedicated imaging protocols is mandatory in order to answer clinical and anatomical questions. Endovascular therapy has taken a predominant role in the therapeutic management of malperfusion syndrome with aortic fenestration, peripheral stenting and stent-grafting, all of which are procedures within the domain of expertise of current interventional radiologists. The purpose of this editorial is to present a when, what and how-to guide for all radiologists who encounter complicated aortic dissection.

Evaluation of radiation during EVAR performed on a mobile C-arm.

BACKGROUND: The aim of this study was to evaluate radiation exposure during aortic endovascular aneurysm repair (EVAR) on a mobile C-arm using a low dose and pulse mode. METHODS: We performed a retrospective analysis of a prospectively maintained database on patients undergoing EVAR. Indirect dose measurements of dose area product (DAP, mGy m²) calculated by the C-arm (OEC 9900MD), fluoroscopic time (FT), type of procedure, contrast media volume and body mass index were analysed. To confirm the correlation between direct and indirect DAP measurements, direct dose was measured with radiochromic films on a sample of 15 patients. Film grey level response was calibrated according to a reference dose measurement performed with a calibrated dosimeter. DAP and peak skin dose (PSD, Gy) were measured on each film. Correlation between DAP from direct and indirect measures, and between DAP and PSD, were analysed. RESULTS: From January 2009 to April 2011, 335 patients underwent EVAR. Complete data were available on 301 procedures including 188 bifurcated, 54 fenestrated, 28 thoracic, 20 branched and 11 aorto-uni-iliac endografts implantation. The respective median FT and DAP was 9.36 min (1.8-67) and 3 mGy m(2) (0.4-28); 27.2 min (2-69) and 7.3 mGy m(2) (1.2-29); 7.75 min (1.2-19.1) and 2 mGy m(2) (0.3-11); 42.98 min (2.4-95.4) and 15.95 mGy m(2) (2.98-77.7); 6.2 min (0.5-36.3) and 2 mGy m(2) (0.3-11). Direct DAP measurement on radiochromic films was strongly correlated with DAP values provided by the C-arm (r = 0.98). PSD correlated weakly with DAP. DAP was significantly increased (p < 0.001) in patients with a body mass index >30. Contrast media volume was significantly increased in the branched endograft group. CONCLUSION: Indirect DAP values measured by the C-arm are accurate to evaluate radiation exposure. Compared to the literature, our values for standard procedures are significantly decreased by the usage of low dose and pulse mode. DAP for fenestrated and branched procedures was comparable to published DAP values with standard procedures using a regular fluoroscopic mode.

Technical note and results in the management of anatomical variants of renal vascularisation during endovascular aneurysm repair.

INTRODUCTION: The revascularisation of large (>3 mm) renal arteries emerging from the proximal sealing zone or off the aneurismal wall can be challenging during endovascular aortic aneurysm repair. In this article, we describe various endovascular techniques using custom-made endografts to treat these complex variant anatomies. CASES: Nine patients deemed unfit for open repair with unusual renal vascularisation associated with aortic aneurysms were treated by endovascular means. After three-dimensional (3D) reconstructions on a dedicated workstation, custom-made devices were designed and manufactured. The revascularisation of multiple renal arteries and aberrant origins of renal arteries, associated or not with pelvic kidney or horseshoe kidney, was managed using fenestrated and branched endografts. RESULTS: All target vessels were patent on computed tomography (CT) scan and contrast-enhanced ultrasound evaluation before discharge as well as on the 6-month follow-up. One patient presented a decrease of postoperative glomerular filtration rate over 30% but did not require dialysis. No sac enlargement was depicted, and no reintervention was performed during follow-up. Three type 2 endoleaks were diagnosed. CONCLUSION: Endovascular treatment with fenestrated and branched endografts should be considered in challenging renal artery anatomies in patients unfit for open repair.

Endovascular approaches to acute aortic type A dissection: a CT-based feasibility study.

BACKGROUND: Open graft replacement of the ascending aorta is the current treatment of choice for Stanford acute type A dissections. However, approximately 20% of patients are deemed unfit for open surgery. To determine if an endovascular option exists for this latter group of patients, we performed a computed tomography (CT)-based feasibility study. METHODS: A cohort of consecutive patients presenting to the cardiovascular care unit (CVCU) for an acute Stanford type A aortic dissection between 2006 and 2009 was retrospectively analysed. Inclusion criterion was a high-quality preoperative angio-CT scan that could be analysed on a three-dimensional (3D) workstation. Numerous anatomical parameters of the dissection were studied, including the location and the length of the primary proximal entry tear. Finally, we determined which of the patients would have been potential candidates for an endovascular repair (stentgraft implantation). RESULTS: A total of 102 patients were included in our study. The median distance of the primary entry tear to the closest coronary artery was 23 mm (range 0-128). The median true lumen and true + false lumen (total) diameters at the level of the entry tear was 38 mm (range 22-78) and 46 mm (range 28-93), respectively. The median length of the ascending aorta was 84 mm (range 40-130). An endovascular repair with a tubular stentgraft was deemed feasible in 37 patients. An additional eight patients were also candidates for a tubular endovascular repair but would have required a carotidecarotid cross over bypass. Finally, an arch-branched stentgraft could have been used in 13 patients to exclude an entry tear located in the arch. CONCLUSION: Open repair of acute type A dissection is and remains the 'gold standard' of care. Our study demonstrates that approximately half the patients undergoing an open repair could potentially benefit from an endovascular repair. This new treatment option has not been evaluated to date.

Single-centre prospective comparison between contrast-enhanced ultrasound and computed tomography angiography after EVAR.

AIM: To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to CT-angiography (CTA) for endoleak detection and aneurismal sac diameter measurement in the follow-up after endovascular abdominal aortic aneurysm repair (EVAR). METHODS: From January 2006 to December 2010, 395 patients underwent EVAR follow-up with both CTA and CEUS. The diameter of the aneurismal sac and the presence of endoleaks were evaluated in all the 395 paired examinations. RESULTS: Bland-Altman plots showed a good agreement in aneurismal sac diameter evaluation between the two imaging modalities. The mean diameter was 54.93 mm (standard deviation (SD) ±12.57) with CEUS and 56.01 mm (SD ± 13.23) with CTA. The mean difference in aneurismal sac diameter was -1.08 mm ± 3.3543 (95% confidence interval (CI), -0.75 to -1.41), in favour of CTA. The number of observed agreement in endoleak detection was 359/395 (90.89%). The two modalities detected the same type I and type III endoleaks. McNemar's χ(2) test confirmed that CTA and CEUS are equivalent in endoleak detection. CONCLUSIONS: CEUS demonstrated to be as accurate as CTA in endoleak detection and abdominal aortic aneurysm diameter measurements during EVAR follow-up, without carrying the risks of radiation exposure or nephrotoxicity. Even if it cannot be proposed as the sole imaging modality during follow-up, our analysis suggests that it should have a major role.

[MR imaging of coronary arteries: noncontrast free-breathing whole heart acquisition with ultrafast 3D balanced gradient-echo technique]. / Imagerie par résonance magnétique des artères coronaires: acquisition "coeur entier", en respiration libre, sans injection d'agent de contraste et utilisant la séquence 3D en écho de gradient balancé ultrarapide.

The 3D balanced gradient-echo technique is described along with th eimaging protocol for MR imaging of th ecoronary arteries. A 3D volume with spatial resolution of 0.6 x 0.6 x 0.75 mm composed of 140 slices covering the whole heart is acquired over 10 minutes. The main advantage of this whole heart technique is the possibility to image the coronary arteries along their entire course in a single acquisition. Selection of the navigator positions, timing of image acquisition and its duration through the R-R interval are the main factors requiring optimization.

Endovascular stenting for chronic femoro-iliac venous obstructive disease: Clinical efficacy and short-term outcomes.

PURPOSE: To report the clinical efficacy and mid-term outcomes of endovascular treatment in patients with chronic, symptomatic, post-thrombotic femoro-iliac venous obstruction. MATERIALS AND METHODS: Forty-two patients with post-thrombotic syndrome (PTS) presenting with femoro-iliac venous obstructive lesions treated in our institution by endovascular approach between March 2012 and October 2017 were retrospectively included. There were 27 women and 15 men with a mean age of 47.3±17 (SD) years (range: 22-86 years). Procedure included first venous recanalization, then pre-dilatation and self-expandable metallic stenting of the narrowed or occluded iliac and/or femoral veins. Severity of PTS and quality of life were assessed at baseline and 3 months after the intervention respectively, using Villalta score and Chronic Venous Insufficiency Questionnaire (CIVIQ-20) scale. Imaging follow-up evaluation of stent patency was based on the results of duplex Doppler ultrasound and computed tomography. RESULTS: Immediate technical success was achieved in 41/42 (97.6%) patients, without any major complications. Primary patency, primary assisted patency and secondary patency at the end of the median imaging follow-up of 18.1 months (IQR, 9.7-34.4) were achieved in 29/42 (66.7%) patients, 33/42 (78.6%) patients and 37/42 (88.1%) patients, respectively. Median Villalta and CIVIQ-20 scores decreased from 14 (IQR, 10-19) and 57 (IQR, 39-72) at baseline, respectively, to 5 (IQR, 2-9) and 30 (IQR, 24-50) 3 months after the procedure, respectively (P<0.0001), showing significant decrease in the severity of PTS and improvement in the quality of life. The multiple linear regression model showed that both baseline Villalta and CIVIQ-20 scores ([95% CI: -7.80-3.79; P<0.0001] and [95% CI: 0.07-0.20; P<0.0001], respectively), age (95% CI: 0.04-0.19; P=0.002) and stenting expanse (95% CI: 0.97-5.65; P=0.006) were independent variables related to Villalta gain. Baseline Villalta (95% CI: 0.89-2.23; P<0.0001) was the single independent variable related to CIVIQ-20 gain. CONCLUSION: This study confirms the high clinical efficacy and favorable mid-term outcomes of endovascular stenting in patients with chronic symptomatic femoro-iliac venous obstructive lesions.

Source of oncofetal ED-B-containing fibronectin: implications of production by both tumor and endothelial cells.

ED-B fibronectin (FN) is a FN isoform derived from alternative splicing of the primary transcript of a single gene. Its expression on tumor stroma and neoformed tumor vasculature and its absence, with few exceptions, in normal adult tissues imply a prognostic and diagnostic value for ED-B FN. We investigated the location and source of ED-B FN because this will be of importance both in understanding its role in tumor development and in designing strategies to target this molecule. We have confirmed that ED-B FN is expressed in the majority of breast and colorectal carcinoma tissue samples, with strong immunohistochemical staining around the tumor cells and in the tumor stroma. No staining of tumor neovasculature was seen. ED-B FN is produced by a range of tumor and endothelial (both primary and transformed) cell lines, as detected by reverse transcription-PCR, but is not expressed at the plasma membrane. Strong expression of human ED-B FN is seen in tumor xenografts. These data indicate that neoplastic cells can act as the source of ED-B FN in tumors. The lack of cell surface expression on tumor cell lines has clear implications for the design of therapeutic strategies which target this molecule.

Acute cerebellar ataxia in pediatric legionellosis.

Acute-phase and convalescent-phase sera of 66 children, aged 3 months to 12 years, with neurologic disorders of unknown etiology were tested against Legionella pneumophila polyvalent and monovalent antigens (groups 1 to 4). Three significant antibody titer increases were obtained, all in children with acute cerebellar ataxia. This neurologic syndrome was characterized by sudden onset of muscle hypotonia and inability to sit or walk, with no other specific neurologic or systemic symptoms. Persisting pharyngitis always preceded ataxia. Fever of short duration was still present. Gastrointestinal disturbance occurred in two of the three children. Abnormal laboratory findings were, not always simultaneously, high ESR and leukocytosis with lymphocytosis. CSF levels and electromyographic findings were normal in two of the children. Two children received oral betamethasone. Recovery was complete within seven to ten days without antibiotic treatment. These studies indicate the possible etiologic role of L pneumophila in acute cerebellar ataxia.

Hepatitis in pre-school children: prevalent role of cytomegalovirus.

Virological and serological investigations were performed on 8 children with clinical and/or laboratory signs of hepatitis. Cytomegalovirus (CMV) appeared as the most frequently involved etiologic agent, since it was associated with 5 severe or chronically-evolving cases. Out of the other 3 patients with non-CMV associated hepatitis, all completely recovering, two had clinically typical Epstein-Barr virus infections, while the remaining patient had an asymptomatic HBV infection.

Hepatitis in children with thalassemia major.

Since thalassemia major patients are transfusion dependent, they are at a particularly high risk of contracting post-transfusion hepatitis. In this study, 36 transfusion-dependent children were followed up for evidence of viral hepatitis. Of 23 with increased ALT levels, 17 were anti-CMV and 12 were anti-HCV positive, 9 were positive for both CMV and HCV. Of 13 children with normal transaminase levels, 5 were CMV positive and 3 were HCV positive. These results show that CMV may be a very common cause of non-A, non-B hepatitis in transfusion dependent thalassemic children.

Determination of vaccine-induced and naturally acquired class-specific mumps antibodies by two indirect enzyme-linked immunosorbent assays.

Paired sera from 46 vaccinees and 22 patients with clinically typical or atypical parotitis were tested for class-specific mumps antibodies by two different indirect enzyme-linked immunosorbent assay (ELISA) procedures. Both ELISAs appeared suitable, specific and more sensitive than neutralization (NT) and complement-fixation (CF). However, the macro-ELISA (M-ELISA) method, using beads as antigen-coated solid phase, showed a higher sensitivity than micro-ELISA (m-ELISA), performed on microplates. Diagnostic rises in mumps IgG antibodies and mumps IgA antibodies were detected more frequently by M-ELISA, mostly in post-vaccination sera. In addition, higher mean OD values of mumps IgG, IgA and IgM antibodies were generally found by M-ELISA. Nevertheless, m-ELISA appeared more convenient for evaluating class-specific mumps antibodies in large-scale studies, since the procedure is simpler, more rapid and less expensive than that of M-ELISA. Conversely, M-ELISA may be considered the test of choice for detecting low class-specific antibody levels. However, the determination of class-specific mumps antibodies appeared as an essential tool for evaluating vaccine-induced or naturally acquired mumps immunity.

Sexually active adolescents and young adults: a high-risk group for Chlamydia trachomatis infection.

BACKGROUND: The importance of travel as a risk factor for Chlamydia trachomatis infection was evaluated among a series of young people consecutively tested. METHODS: We studied 130 sexually active young subjects, aged 14-25 years, all living in the Rome, Italy, urban area. Ninety-eight females and 32 males attended hospital-based clinics or were the partners of an infected female. About half of these subjects had traveled abroad either for pleasure or for work, mostly to Europe, but also to North America or to Asia, where they admitted to having had casual sex. We used two "gold standard" methods to diagnose infection with C. trachomatis: culture on McCoy cells grown in shell vial, and direct immunofluorescence with monoclonal antibodies. Subjects were considered infected when at least one test was positive. RESULTS: Thirty-nine of 130 (30%) subjects were asymptomatic, and 27/130 (20.8%) subjects were infected with Chlamydia trachomatis, of whom 6/25 (24%) asymptomatic females and 3/14 (21.4%) asymptomatic males were infected. Among teen-aged (ages 14-19) youngsters with more than one sex partner, international travel was an additional significant risk factor for C. trachomatis infection (p<.02; OR 20; 95% CI 1.47-40%). Urethritis/cystitis and vaginal pathology/discharge were the prevalent manifestations of illness among the females, while urethritis was the only clinical condition found in the males. CONCLUSION: In a series of young subjects, travel abroad, sex with more than one partner, and teen age, combined together, were significant risk factors for the acquisition of Chlamydia trachomatis genitourinary infection.

Chlamydia trachomatis infection monitoring with cytomorphology, direct immunofluorescence and "in vitro" growth method.

The increased occurrence of genital infections from Chlamydia trachomatis (Ct) suggested the need for a simple, rapid, sensitive method for detection of Ct. The purpose of the present study was to select symptomatic or asymptomatic women through two fast screenings: Pap-test and direct immunofluorescence (IF) test with monoclonal antibody. From 1,816 cervical cytology samples, 32 (1.76%) were selected for intracytoplasmic inclusions pathognomonic of Ct infection. Only 19 women underwent a check-up. The direct IF gave positive results in ten cases out of 19 (52.63%), and culture in eleven (57.89%). A correlation was made between the direct IF test and culture and also between cytologic and colposcipc findings. We thus conclude that direct IF, for its specificity, sensitivity, easy execution and low cost, could be currently utilized when clinical signs or Pap smears are suggestive of Ct infections.

Clostridium difficile isolation in leukemic children on maintenance cancer chemotherapy. A preliminary study.

Between December 1982 and November 1983, stool specimens from 15 children with acute lymphoblastic leukemia, who were on maintenance cancer chemotherapy, were examined weekly for the presence of Clostridium difficile and its toxin. Four out of 15 patients were positive for C. difficile: three patients had stool specimens that did not contain toxin, but cultures yielded growth of toxigenic C. difficile on only one occasion. The fourth patient, who had a recent history of hospitalization, particularly aggressive cancer chemotherapy, neutropenia, and antibiotic therapy, excreted both C. difficile and its toxin for at least 1 month. All children were asymptomatic at the time of positive cultures. This preliminary study reveals a low rate of C. difficile colonization in leukemic children on maintenance cancer chemotherapy.