The Effect of a Suspended Radiation Protection System on Occupational Radiation Doses During Infrarenal EVAR Procedures: A Randomised Controlled Study.

OBJECTIVE: To compare the protective effect of Zero Gravity (ZG) with conventional radiation protection during endovascular aneurysm repair (EVAR). Secondly, user experience was surveyed with a questionnaire on ergonomics. METHODS: This was a single centre, prospective, randomised, two arm trial where 71 consecutive elective infrarenal EVAR procedures were randomised into two groups: (1) operator using ZG and assistant using conventional protection (n = 36), and (2) operator and assistant using conventional radiation protection (n = 35). A movable floor unit ZG system consists of a lead shield (1.0 mm Pb equivalent) for the front of the body and 0.5 mm Pb equivalent acrylic shielding for the head and neck. The ZG also includes arm flaps of 0.5 mm Pb equivalent covering the arm up to the elbow. Deep dose equivalent values, Hp(10) were measured with direct ion storage dosimeters (DIS) placed on various anatomical regions of the operator (axilla, chest, abdomen, and lower leg). Personal dose equivalent values, Hp(3) to eye lenses were measured in the operating and assisting surgeon using thermoluminescence dosimeters. The study was registered at the US National Institute of Health #NCT04078165. RESULTS: Protection with the standard protection was superior in chest (0.0 vs. 0.1 µSv), abdomen (0.0 vs. 0.6 µSv), and lower leg (0.4 vs. 2.2 µSv) (p < .001). On the other hand, the ZG system yielded better shielding for the axilla (1.5 vs. 0.0 µSv) and eyes (6.3 vs. 1.1 µSv) of the operator. The use of ZG hampered the deployment of ancillary shields, which is particularly relevant for protection of the assisting surgeon. Users found ZG more cumbersome than conventional garments, it also impaired communication and reduced field of view. CONCLUSION: Both ZG and conventional radiation protection reduced radiation exposure. Conventional protection allows better manoeuvrability at the price of wider exposure of the upper arm and axilla. ZG indirectly impaired protection of the assistant.

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards.

OBJECTIVE: There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study. METHODS: The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80. RESULTS: All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items. CONCLUSION: This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.

Contemporary management of infective native aortic aneurysms.

PURPOSE OF REVIEW: Infective native aortic aneurysms (INAAs) are challenging and complex with both bacteraemia and an aneurysm prone to rupture. They are fatal unless recognized and treated promptly. The rarity of the disease makes it unfamiliar to most physicians, which might delay both diagnosis and treatment.The present review aims to outline the recently published diagnostic algorithm of INAAs, the main characteristics of the disease and present an overview of contemporary treatment strategies. RECENT FINDINGS: New terminology, definition, diagnostic algorithm and reporting standards have recently been proposed for INAAs. Current evidence concerning the treatment of INAAs is founded on retrospective register-based multicentre studies and small single-centre studies. Recent findings encourage the use of endovascular aortic repair (EVAR) for surgical treatment of INAAs. Although EVAR, as a surgical approach, does not drain the infection, the postoperative infection-related complication rates (IRCs) are similar to the ones reported after open surgical repair (OSR) with aortic prosthetic reconstruction and extensive debridement. IRCs carry over 50% risk of being fatal. Postoperative mortality after EVAR remains considerably lower supporting the use of method for aged and comorbid group of patients. Biological grafts have the benefit of being more resistant to reinfection. OSR with biological reconstruction is a promising surgical approach for patients fit for open surgery; however, data are scarce and long-term follow-up is lacking. SUMMARY: The treatment of INAAs should be guided by experienced multidisciplinary team and tailored individually based on patients' condition and centres' experience. An international consensus document is warranted to enable further research on this disease.

The value of 18F-FDG-PET-CT in the management of infective native aortic aneurysms.

OBJECTIVE: The objective of this systematic literature review was to explore the value of positron emission tomography combined with low-dose computed tomography (18F-FDG-PET-CT) in the diagnostics of infective native aortic aneurysm (INAA). METHODS: A systematic literature review was performed using the search terms mycotic- and infected aortic aneurysms in Medline and Sciencedirect databases, published between 1 January 2000 and 1 January 2020. Using the PRISMA statement, articles were scrutinized according to a predefined protocol including: timing of 18F-FDG-PET-CT examination, the maximum standardized uptake value (SUVmax), additional findings on examination, and findings on repeated scanning of 18F-FDG-PET-CT. RESULTS: Four studies were included in the analysis, comprising a total of 11 patients. Two studies were single case reports, and two were small case series, all were graded to be of low quality with high risk of bias. All patients were examined with a preoperative 18F-FDG-PET-CT, and 10 (91%) had increased 18F-FDG uptakes. The median SUVmax value was 6.53, range 4.46-9.23. The mean duration of antibiotic therapy prior to 18F-FDG-PET-CT was not known. Two patients were examined with repeated 18F-FDG-PET-CT examinations after treatment, where a decrease in SUVmax values could be demonstrated after successful treatment. CONCLUSION: The literature on 18F-FDF-PET/CT for diagnosing infective native aortic aneurysms is scarce. However, there might be a role for 18F-FDF-PET/CT in the management of the disease, in particular for patients with clinical suspicion of INAA without convincing findings on CT. SUVmax values ranging from 4.5 to 6.5 could be guiding and suggestive of metabolic activity in agreement of INAA. However, further conclusions on its usefulness, robustness and specific SUVmax values are premature, and a definitive cut-off value is probably not attainable.

Cryopreserved Venous Allografts in Supra-inguinal Reconstructions: A Single Centre Experience.

OBJECTIVE: This study introduces a novel technique for supra-inguinal arterial reconstructions with cryopreserved femoral vein and caval allografts with a low re-infection rate and an acceptable graft re-intervention rate on early mid term analysis. METHODS: Patients treated from February 2012 to March 2018 with cryopreserved venous allograft reconstructions owing to infection in the supra-inguinal area were reviewed retrospectively. The primary end points were re-infection and the treatment related mortality rate. Secondary end points were 30 and 90 day and overall mortality and graft re-intervention rate. RESULTS: Of the 23 patients treated with cryopreserved venous allografts for infection in aorto-iliac area, 21 (91%) patients underwent reconstruction with cryopreserved femoral veins and two (9%) with vena cava. Indications for treatment were aortic graft infections (n = 12 [52%]), mycotic aneurysms (n = 5 [22%]), femorofemoral prosthetic infections (n = 3 [13%]), anastomotic pseudo-aneurysms (n = 2 [9%]), and aortic thrombosis with intestinal spillage (n = 1 [4%]). In hospital and 90 day mortality were 9% (n = 2); overall treatment related mortality during the median follow up of 15 months was 13% (n = 3). During the follow up, two allografts were re-operated on owing to anastomotic dilatation and one because of re-infection, resulting in a re-intervention rate of 13% (n = 3). None of the grafts was lost and there were no amputations. At the end of follow up 17 patients (74%) were alive. Kaplan-Meier estimation for survival was 76% (95% confidence interval [CI] 57%-95%) at one year and 70% (95% CI 49%-91%) at two years. CONCLUSION: Cryopreserved venous allografts appear to be an infection resistant and reasonably safe reconstruction material in the aorto-iliac axis based upon the early mid term analysis from a single centre experience. Further research is needed to compare their performance with other biological reconstruction material.

Open Repair of Mycotic Abdominal Aortic Aneurysms With Biological Grafts: An International Multicenter Study.

BACKGROUND: The treatment of mycotic abdominal aortic aneurysm requires surgery and antimicrobial therapy. Since prosthetic reconstructions carry a considerable risk of reinfection, biological grafts are noteworthy alternatives. The current study evaluated the durability, infection resistance, and midterm outcome of biological grafts in treatment of mycotic abdominal aortic aneurysm. METHODS AND RESULTS: All patients treated with biological graft in 6 countries between 2006 and 2016 were included. Primary outcome measures were 30- and 90-day survival, treatment-related mortality, and reinfection rate. Secondary outcome measures were overall mortality and graft patency. Fifty-six patients (46 males) with median age of 69 years (range 35-85) were included. Sixteen patients were immunocompromised (29%), 24 (43%) had concomitant infection, and 12 (21%) presented with rupture. Bacterial culture was isolated from 43 (77%). In-situ aortic reconstruction was performed using autologous femoral veins in 30 patients (54%), xenopericardial tube-grafts in 12 (21%), cryopreserved arterial/venous allografts in 9 (16%), and fresh arterial allografts in 5 (9%) patients. During a median follow-up of 26 months (range 3 weeks-172 months) there were no reinfections and only 3 patients (5%) required assistance with graft patency. Thirty-day survival was 95% (n=53) and 90-day survival was 91% (n=51). Treatment-related mortality was 9% (n=5). Kaplan-Meier estimation of survival at 1 year was 83% (95% confidence interval, 73%-94%) and at 5 years was 71% (52%-89%). CONCLUSIONS: Mycotic abdominal aortic aneurysm repair with biological grafts is a durable option for patients fit for surgery presenting an excellent infection resistance and good overall survival.

Temporary Axillorenal Bypass in Complex Aorto-Renal Surgery.

BACKGROUND: Prolonged renal ischemia during vascular surgery carries high morbidity and mortality. We report an alternative technique for maintaining renal circulation during suprarenal aortic or renal artery clamping. METHODS: Between October 2007 and May 2012, 16 patients undergoing aorto-renal surgery (13 men, 3 women) were operated using temporary axillorenal bypass. Operations were performed for supra- and juxtarenal aortic aneurysms (11), occlusive aortic disease (2), renal artery stenoses (2), and abdominal myofibroblastic tumor (1). In elective cases, axillorenal bypass was planned, when prolonged renal ischemia was expected based on preoperative information. Preoperative risk factors (renal dysfunction, hypertension, coronary disease, diabetes, smoking) and intraoperative variables (operating time, blood loss, renal ischemia time) were assessed and compared with postoperative kidney function (serum creatinine, urine output, dialysis) and in-hospital or 30-day-mortality. Even though renal blood flow was restored between clampings, the total cumulative ischemia time was used in analysis. Acute renal failure postoperatively was based on RIFLE criteria. RESULTS: Preoperatively, 44% (7) of the patients had normal renal function (S-crea ≤ 100 mmol/L). Renal function was moderately present in 50% (8) (S-crea 100-200 mmol/L) and severely in 6% (1) (S-crea ≥ 200 mmol/L). Median operation time was 393 min (251-535 min) and median renal ischemia time was 24.5 min (range 8-50 min). Transient acute renal dysfunction occurred in 6 (38%) patients, and 4 of them had renal insufficiency preoperatively. Transient renal replacement therapy was needed in 1 (6%) patient only. In 1-month control, postoperative renal function had returned to its baseline level or improved and in-hospital or 30-day mortality was zero. CONCLUSIONS: Temporary axillorenal bypass is a considerable option to minimize renal ischemia time during high-risk vascular surgery.