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 allcause mortality. However, results from running 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 on a general basis is cost-effective under current clinical practice.

Methods: A decision-analytic model, previously used to show the cost-effectiveness of an AAA-screening programme before decision to introduce screening in practice, was updated using results from implemented screening-programmes as well as data from contemporary published data and the Swedvasc registry.

Results: The base-case analysis showed that the cost per life-year gained and quality-adjusted life year (QALY) gained were 3252 € and 4231 €, respectively. The probability of screening being cost-effective was high.

Conclusion: Despite profound changes in disease pattern and AAA-management, the current results are similar to those reported almost 10 years ago, and thus screening 65-year-old men for AAA still appears to be cost-effective.

Objectives: Screening 65-year-old men for abdominal aortic aneurysm (AAA) reduces mortality from ruptured AAA (rAAA). Lower than expected prevalence of AAA is now found, why screening at a higher age and rescreening has been discussed. Our aim was to determine if screening at 70 years of age, instead of 65, increases clinical effectiveness.

Methods: 7951 and 5623 previously un-screened 65- and 70-year old men were invited to ultrasound screening.

Results: The attendance rate was 85.7% and 84.0%, p<0.01, for the 65- and 70-year old men respectively. The screening-detected prevalence did not differ, being 1.9% and 2.3%, p=0.15, respectively, probably due to the fact that 23.5% and 37.4% of all known AAA among 65- and 70-year-old men, were detected by other means prior to screening, p<0.01. However, the total known prevalence differed between the age-groups, being at least 2.1% and 3.0% respectively, p<0.001.

Conclusion: The screening-detected AAA-prevalence did not differ between 65- and 70-yearold men, due to the greater number of AAA known prior to screening among 70- compared to 65-year-old men. Screening men at 70 instead of 65 years of age would not result in detection of substantially more previously unknown AAA, thus not preventing rAAA and consequently not more saved life-years. Further, data also indicates that it is questionable if re-screening the 65-year-old male population after five years would generate any important clinical effect.

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. less thanbrgreater than less thanbrgreater thanMethods: 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. less thanbrgreater than less thanbrgreater thanResults: 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: chi(2) = 4.2 [degrees of freedom 1; P=0.041]; secondary patency: chi(2) = 4.3 [degrees of freedom 1; P=0.037]) but not for limb salvage (limb salvage: chi(2) = 0.2 [degrees of freedom 1; P=0.657]). less thanbrgreater than less thanbrgreater thanConclusions: External support to a PTFE graft used for bypass to below-knee arteries improves primary and secondary patency but not limb salvage.

Background

Screening 65-year-old men for abdominal aortic aneurysms (AAA) is a cost-effective method to reduce the mortality from ruptured AAA. However, contemporary results show a lower than expected prevalence of AAA, thus questioning the benefit of screening. Since the prevalence increases with age, a possible way to enhance the benefit of screening might be to screen older men. Our aim was to determine the contemporary screening-detected prevalence among 70-year-old men.

Methods

A total of 5,623 unscreened 70-year-old men were invited to ultrasound screening. Uni- and multivariable analyses were used to assess the risk factors for AAA.

Results

The attendance rate was 84.0%. The prevalence of previously unknown AAAs was 2.3%. When adding the 64 men with an already known AAA to the screening-detected ones, the total prevalence in the population was at least 3.0%, and the previously discovered AAAs constituted 37.4% of the total prevalence. “Ex smoker” and “Current smoker” were the most important risk factors.

Conclusions

When screening 70-year-old men for AAA, the prevalence was less than half that expected, despite a high attendance rate. Smoking was the strongest risk factor. Almost 40% of the men with AAAs were already known from other means than screening.

AIM:

Is there a difference in the population-based survival rate for patients with ruptured abdominal aortic aneurysms (rAAA), handled by a "one-stop" or a "two-stop" referral pattern?

METHODS:

Ten regions in Sweden were identified where clear-cut "one-stop" or "two-stop" referral-patterns prevailed. From the Swedvasc Registry we identified 849 patients operated on for rAAA, 1987 to 2004, living in any of these ten regions, and related the number of survivors to the whole population served by each hospital.

RESULTS:

The population-based survival rate was 14% lower for patients following a "two-stop" compared to a "one-stop" referral pattern (P=0.084). For the group 65-74 years-of-age the difference was significant (P=0.021), but no corresponding effect was seen regarding operative mortality rate or sex.

CONCLUSION:

Compared to a "one-stop" referral pattern for rAAA, a "two-stop" referral pattern results in a lower population-based survival rate for patients 65-74 years old, but the consequences would be small even if a "one-stop" referral pattern could be generally accomplished.

Aim. Randomized studies evaluating the effect of a vein collar at the distal anastomosis of PTFE-grafts show conflicting results. The study of the Joint Vascular Research Group (JVRG) of UK found improved primary patency while the Scandinavian Miller Collar Study (SCAMICOS) found neither any effect on patency nor on limb salvage after bypass to below-knee arteries. However, the Scandinavian patients were a decade older and predominately female compared to the British patients. Can this explain the conflicting result? less thanbrgreater than less thanbrgreater thanMethods: Primary patency with respect to sex, age and the use of vein collar were re-analysed in 345 patients from SCAMICOS with Kaplan-Meier life-table technique, log-rank test and Cox proportional hazards regression to evaluate any interaction between sex or age and the effect of a vein collar on the primary patency rate. less thanbrgreater than less thanbrgreater thanResults. Females had better patency than males (log-rank test, chi(2)=9.4, df=1, P=0.002) but age had no influence on patency (log-rank test, chi(2)=3.3, df=3, P=0.35). However, 47% of the males compared to 23% of the females were smokers (P=0.00002). No interaction effect between sex and vein collar (P-value=0.224) or age and vein collar (P-value=0527) was established. less thanbrgreater than less thanbrgreater thanConclusion. The difference between the two randomised vein collar studies are unlikely to depend on the disparity in sex and age of the study populations.

AIM:

The aim of this paper was to study the effect on patency rate of different types of vein collar (Miller's original or St Mary's boot), different length/height shapes of vein collar, and different vein collar volumes at the distal anastomosis of PTFE-bypass grafts to below-knee arteries in patients with critical limb ischemia.

METHODS:

One hundred eighty patients operated on with PTFE-bypass to below-knee arteries with a vein collar at the distal anastomosis were analyzed. They were recruited from a prospective randomized trial evaluating the effect of adding a vein collar to the distal anastomosis. Primary patency rate of the reconstructions were assessed against three factors: the type, shape, and volume of the vein collar. Univariate analysis was performed with the help of plotted Kaplan-Meier lifetable curves and log-rank tests and multivariate analysis with Cox proportional hazards regression.

RESULTS:

Type of vein collar had no influence on primary patency (logrank-test, χ(2)=0.8, df=1, P=0.377, N.=180). A length/height ratio of the vein collar between 1.18 and 1.63 were advantageous for primary patency but the effect was not statistically significant (logrank-test, chisq=5.5, df=2, P=0.063, N.=177). A large volume of the vein collar enhanced primary patency (logrank-test, chisq=6, df=2, P=0.050, N.=173). In the multivariate analysis, however, a larger volume and a length/height ratio between 1.18 and 1.63 as well as > 1.63 reduce the risk of graft failure with 48% (P=0.00006), 58% (P=0.007), 58% (P=0.004), respectively, while vein collar type had no effect on primary patency.

CONCLUSION:

This prospective observational study indicates that if a vein collar is used at the distal anastomosis of a PTFE-bypass to below-knee arteries it should be long compared to height and large in volume to improve primary patency rate, while the type of vein collar does not appear to matter.

Aim. Randomized studies evaluating the effect of a vein collar at the distal anastomosis of PTFE-grafts show conflicting results. The study of the Joint Vascular Research Group (JVRG) of UK found improved primary patency while the Scandinavian Miller Collar Study (SCAMICOS) found neither any effect on patency nor on limb salvage after bypass to below-knee arteries. It has been discussed whether the questioned positive effect of a vein collar is due to technical advantages when the anastomosis is made rather than on a positive influence on the long-term effect by less pseudointima formation. less thanbrgreater than less thanbrgreater thanMethods. Primary patency regarding the use of vein collar were re-analyzed in 345 patients from SCAMICOS with Kaplan-Meier life-table technique and Cox proportional hazards regression in a counting process notation to evaluate any interaction between time-period and the effect of a vein collar on the primary patency rate. less thanbrgreater than less thanbrgreater thanResults. No overall effect on primary patency of a vein collar at the distal anastomosis was found irrespective of the site anastomosis. However, during the first 30 days of follow-up the primary patency among the femoro-crural bypasses was 0.87 (0.79-0.95) and 0.72 (0.63-0.83) with and without vein collar respectively. The interaction between vein collar and time-period was not statistically significant (P=0.070) and neither was the Score test for the whole interaction analysis (P=0.091) for the patients with anastomosis to the crural arteries. No such initial differences were found for the patients with anastomosis to the popliteal artery below-knee. less thanbrgreater than less thanbrgreater thanConclusion. A clinically relevant but not statistically significant better primary patency during the first 30 days was found for patients with PTFE-bypass to the crural arteries with a vein collar at the distal anastomosis. There were no long-term advantages of the vein collar irrespective of the location of the anastomosis.

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