Abdominal aortic aneurysm growth rates are not correlated to body surface area in screened men.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) in 65-year-old males reduces aneurysm related mortality. Infrarenal aortic diameter (IAD) has been shown to correlate to body surface area (BSA) which could influence diagnostic criteria for AAA. This study investigates whether AAA growth rates are also dependent on BSA, as that might have potential effects on surveillance of small AAAs. METHODS: We conducted a retrospective, single center cohort study of 301 men with screening detected AAA between 2010-2017 with surveillance to 2021. AAA growth rates were analyzed in relation to the subject's BSA, smoking habits, and diabetic disease using a linear mixed-effects model. All men were offered smoking cessation program, optimized medical treatment, and advice on physical activity. RESULTS: The screening program included 28,784 men. Of the 22,819 (79%) attending the examinations, 374 men (1.6%) were found to have an AAA out of which 301 men had undergone two or more examinations during surveillance and were included with a median follow-up of 1846 days (IQR: 1 399). Mean unadjusted AAA growth rate was 1.60 mm/year (95% CI: 1.41-1.80). Diabetes mellitus had a statistically significant negative impact, smoking had a statistically significant positive impact on AAA growth rates whereas no correlation between AAA growth rate and BSA could be found. CONCLUSIONS: Body surface area could not be found to have a statistically significant correlation to AAA growth rates. The impact of smoking and diabetes on AAA growth rates remains similar to previously reported.

Risk-adjusted mortality in severely injured adult trauma patients in Sweden.

BACKGROUND: Risk-adjusted mortality (RAM) analysis and comparisons of clinically relevant subsets of trauma patients allow hospitals to assess performance in different processes of care. The aim of the study was to develop a RAM model and compare RAM ratio (RAMR) in subsets of severely injured adult patients treated in university hospitals (UHs) and emergency hospitals (EHs) in Sweden. METHODS: This was a retrospective study of the Swedish trauma registry data (2013 to 2017) comparing RAMR in patients (aged 15 years or older and New Injury Severity Score (NISS) of more than 15) in the total population (TP) and in multisystem blunt (MB), truncal penetrating (PEN), and severe traumatic brain injury (STBI) subsets treated in UHs and EHs. The RAM model included the variables age, NISS, ASA Physical Status Classification System Score, and physiology on arrival. RESULTS: In total, 6690 patients were included in the study (4485 from UHs and 2205 from EHs). The logistic regression model showed a good fit. RAMR was 4.0, 3.8, 7.4, and 8.5 percentage points lower in UH versus EH for TP (P < 0.001), MB (P < 0.001), PEN (P = 0.096), and STBI (P = 0.005), respectively. The TP and MB subsets were subgrouped in with (+) and without (-) traumatic brain injury (TBI). RAMR was 7.5 and 7.0, respectively, percentage points lower in UHs than in EHs in TP + TBI and MB + TBI (both P < 0.001). In the TP-TBI (P = 0.027) and MB-TBI (P = 0.107) subsets the RAMR was 1.6 and 1.8 percentage points lower, respectively. CONCLUSION: The lower RAMR in UHs versus EH were due to differences in TBI-related mortality. No evidence supported that Swedish EHs provide inferior quality of care for trauma patients without TBI or for patients with penetrating injuries.

Treatment choice and survival after ruptured abdominal aortic aneurysm: A population-based study.

OBJECTIVE: The objective of this study was to clarify whether the findings of the randomized studies of repair method (open aortic repair [OAR] vs endovascular aneurysm repair [EVAR]) concerning short-term and midterm survival for ruptured abdominal aortic aneurysms (RAAAs) could be confirmed in a contemporary, nationwide, and unselected population. METHODS: This cohort study is based on prospectively collected data from Swedvasc, a nationwide vascular registry, including all 29 hospitals performing surgery for RAAA in Sweden (3 district, 19 county, and 7 university hospitals) during 2013 to 2015. All 702 patients operated on for RAAA during this time were included. Open surgery and endovascular repair, analyzed on the basis of individual patient repair (OAR vs EVAR) and hospital repair practice (OAR-only vs OAR/EVAR), were compared for short-term and midterm adjusted survival (0-90 days and 3 months-3 years). RESULTS: Endovascular repair was used for 37% (260/702) of the aneurysms. The adjusted hazard ratio after OAR was 1.30 (0.95-1.77; P = .098; n = 702) for 0 to 90 days and 0.63 (0.43-0.93; P = .021; n = 491) for 3 months to 3 years of follow-up compared with EVAR. The adjusted hazard ratio for a practice of OAR-only was 0.73 (0.54-1.00; P = .047; n = 702) for 0 to 90 days and 0.68 (0.45-1.05; P = .080; n = 491) for 3 months to 3 years of follow-up compared with a practice of OAR/EVAR. No interaction between repair practice and short-term survival could be shown for either sex or age. CONCLUSIONS: An OAR/EVAR practice for RAAA is not superior to an OAR-only practice with respect to survival at short-term or midterm follow-up. The results are even compatible with an advantage of OAR-only practice vs OAR/EVAR practice for both follow-up periods. There is no extra benefit for either female or elderly patients with an OAR/EVAR practice.

A significant correlation between body surface area and infrarenal aortic diameter is detected in a large screening population with possibly clinical implications.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) in elderly men reduces aneurysm related mortality. AAA is commonly defined as an infrarenal aortic diameter (IAD) of ≥30 mm, which is based on the definition of an arterial aneurysm as a focal dilation of 150% or more compared to the expected diameter of about 20 mm. The IAD has been shown to correlate to body surface area (BSA). The aim of this study was to investigate the possibility to use an individualized AAA-criteria by using a BSA-based model to refine the screening for AAA. METHODS: We conducted an observational single center cohort study of 25 236 65-year old men invited to AAA screening in Malmö, Sweden 2010-2015. Out of the 19 738 (78.5%) attendees, 14 846 (58.8%) completed a health questionnaire including height, weight and smoking habits. Linear regression analysis was performed between BSA and IAD, taking smoking habits into account. This regression was used to calculate the predicted IAD for each individual according to their BSA. RESULTS: There was a significant correlation between BSA and aortic diameter, rho =0.26 (95% CI: 0.25, 0.28). AAA defined as an IAD≥30 mm was found in 226 men (1.5%) whereas AAA defined as ≥150% larger IAD than predicted according to the individual BSA was found in 299 men (1.9%), a relative difference in AAA detection rate of more than 30% (P<0.001). CONCLUSIONS: We have found a statistically significant correlation between BSA and IAD in a homogenous screening population that could have clinical implications. In men with low BSA, IAD <30 mm might still be ≥150% larger than predicted according to BSA, whereas in men with high BSA, IAD≥30 mm might not be ≥150% larger than predicted. Further follow-up of these subjects is planned to investigate if the first group have an "aneurysm-in-formation," challenging the diagnostic criteria for AAA.

[Endovascular or open surgery for elective abdominal aortic surgery? Evidence from the 5 randomized trials]. / Val av OAR eller EVAR vid buk­aorta­aneurysm är inte givet - Randomiserade studier har utvärderat öppen och endovaskulär kirurgi ­ ingen av metoderna är i allt överlägsen den andra.

Endovascular or open surgery for elective abdominal aortic surgery? Evidence from the 5 randomized trials OAR (open aortic repair) can be demanding for fragile patients, but has good long-term durability. EVAR (endovascular aortic repair) is more lenient, but is associated with life-long controls, more life-threatening reinterventions, a remaining threat of rupture and a possibly increased risk of death by cancer. All patients with an AAA (abdominal aortic aneurysm) must recieve a thorough evaluation of medical risk and expected survival before open/endovascular treatment and a discussion of the short- and long-term risks of the different treatment alternatives.

Revisiting the cost-effectiveness of screening 65-year-old men for abdominal aortic aneurysm based on data from an implemented screening programme.

BACKGROUND: Health economic analyses based on randomized trials have shown that screening for abdominal aortic aneurysm (AAA) cost-effectively decreases AAA-related, as well as all- cause mortality. However, follow-up from implemented screening programmes now reveal substantially changed conditions in terms of prevalence, attendance rate, costs and mortality after intervention. Our aim was to evaluate whether screening for AAA among 65-year-old men is cost-effective based on contemporary data on prevalence and attendance rates from an ongoing AAA screening programme. METHODS: A decision-analytic model, previously used to analyse the cost-effectiveness of an AAA screening programme prior to implementation in clinical practice, was updated using data collected from an implemented screening programme as well as data from contemporary published data and the Swedish register for vascular surgery (Swedvasc). RESULTS: The base-case analysis showed that the cost per life-year gained and quality-adjusted life year (QALY) gained were €4832 and €6325, respectively. Based on conventional threshold values of cost-effectiveness, the probability of screening being cost-effective was high. CONCLUSION: Despite the reduction of AAA-prevalence and changes in AAA-management over time, screening 65-year-old men for AAA still appears to yield health outcomes at a cost below conventional thresholds of cost-effectiveness.

External support of a polytetrafluoroethylene graft improves patency for bypass to below-knee arteries.

BACKGROUND: Patency and limb salvage after synthetic bypass to the arteries below the knee are inferior to that which can be achieved with autologous vein. The use of external support of synthetic polytetrafluoroethylene (PTFE) grafts to the below-knee position has been suggested to improve patency and limb salvage, a problem analyzed in this randomized clinical trial. We examined whether external graft support improves patency and/or limb salvage in patients undergoing reconstruction with synthetic PTFE grafts to the below-knee arteries. METHODS: Three hundred thirty-four patients with critical limb ischemia undergoing PTFE bypass to below-knee arteries were randomly assigned to have an ordinary PTFE graft or one with external support. Follow-up was scheduled until amputation, death, or at most 5 years, whichever event occurred first. RESULTS: Patients in both the femoropopliteal and femorodistal groups were randomized to have an externally supported PTFE graft (101/195 patients in the femoropopliteal group and 72/139 patients in the femorodistal group). Follow-up information was available for 329 of 334 randomized patients (99%). At 1 year postprocedure, primary patency for below-knee bypass was 0.55 (95% confidence interval [CI], 0.47-0.64) with and 0.42 (95% CI, 0.34-0.50) without externally supported PTFE grafts, and secondary patency was 0.58 (95% CI, 0.51-0.67) and 0.47 (95% CI, 0.39-0.56), respectively. The corresponding figures for limb salvage were 0.75 (95% CI, 0.68-0.82) and 0.69 (95% CI, 0.62-0.77), respectively. The log rank test revealed statistically significant differences between patients with or without externally supported grafts for patency (primary patency: χ2=4.2 [degrees of freedom=1; P=0.041]; secondary patency: χ2=4.3 [degrees of freedom=1; P=0.037]) but not for limb salvage (limb salvage: χ2=0.2 [degrees of freedom=1; P=0.657]). CONCLUSIONS: External support to a PTFE graft used for bypass to below-knee arteries improves primary and secondary patency but not limb salvage.

Informing the efficient use of health care and health care research resources - the case of screening for abdominal aortic aneurysm in Sweden.

BACKGROUND: An analytical framework using Bayesian decision theory and value-of-information analysis has recently been advocated for the economic evaluation of health technologies. The purpose of this study was to apply this framework to screening for abdominal aortic aneurysm (AAA) in Sweden and to compare the conclusions from this study with the conclusions presented in an assessment performed by the Swedish Council of Technology Assessment (SBU). METHODS: A probabilistic decision-analytical model was developed to establish the cost-effectiveness of a screening programme for AAA relative to current clinical practice and to calculate the value-of-information. RESULTS: The cost per quality-adjusted life-year for screening was 9700 euro. The expected value of perfect information for the assessment of overall cost-effectiveness was low, suggesting little benefit in conducting further research. Expected value of perfect partial information indicated that rupture probabilities were associated with the highest uncertainty. By contrast, the SBU report concluded there was limited evidence of cost-effectiveness and proposed further research. CONCLUSION: The investigated screening programme for AAA is likely to be cost-effective and conducting another clinical trial is unlikely to add much valuable information to this decision problem. These recommendations contrast with the vaguer recommendations from SBU that more evidence is required of costs-effectiveness.