Advertisement

Editor's Choice – Trend-break in Abdominal Aortic Aneurysm Repair With Decreasing Surgical Workload

Open ArchivePublished:April 05, 2017DOI:https://doi.org/10.1016/j.ejvs.2017.02.031

      Background

      The epidemiology and management of abdominal aortic aneurysms (AAAs) has changed drastically in the past decades, with implementation of nationwide screening programs, introduction of endovascular repair (EVAR), and reduced prevalence of the disease. This report aims to assess recent trends in AAA repair epidemiology in Sweden in this context.

      Methods

      Primary AAA repairs registered in the nationwide Swedish Vascular Registry (Swedvasc) 1994–2014 were analyzed regarding patient characteristics, repair incidence, technique, and outcome. Four time periods were compared: 1994–1999, 2000–2004, 2005–2009, and 2010–2014.

      Result

      The incidence of intact AAA repair increased (18.4/100,000 1994–1999, 27.3/100,000 2010–2014, p < .001) predominantly among octogenarians (12.7/100,000 1994–1999, 36.0/100,000 2010–2014, p < .001). The utilization of EVAR increased (58% of all intact AAA repairs 2010–2014), especially among octogenarians (80% 2010–2014). During the last time period, however, the incidence of intact AAA repair stabilized, despite an increasing number of screening-detected AAAs operated on (19% in 2010–2014). Short- and long-term outcome after intact AAA repair continued to improve, most pronounced among octogenarians (30-day mortality 9% 1994–1999, 2% 2010–2014, p < .001). The incidence of ruptured AAA repair steadily decreased (9.2/100,000 1994–1999, 6.9/100,000 2010–2014, p < .001) and the use of EVAR for ruptures increased (30% in 2010–2014). The previously observed improvement of short- and long-term outcome after ruptured AAA repair (30-day mortality 38% 1994–1999, 28% 2010–2014, p < .001) stalled during the last time period. The overall 30-day mortality after ruptured AAA repair was 22% after EVAR versus 31% after open repair in 2010–2014. The corresponding mortality for octogenarians was 28% versus 42%.

      Conclusions

      For the first time, a halt in intact AAA repair workload could be identified. This trend-break occurred despite continued increase in treatment of octogenarians and screening-detected aneurysms. Additionally, the ruptured AAA repair incidence continued to decrease. These findings, together with the sustained improvement in survival after AAA repair, may have important impact on planning of vascular surgical services.

      Keywords

      The present study adds knowledge about recent trends in abdominal aortic aneurysm (AAA) epidemiology in the light of the introduction of endovascular management, screening, and decreasing AAA prevalence. It describes a marked decrease in ruptured AAA repair rate, a stabilization of intact AAA repair rate and ever improving survival rates.

      Introduction

      In the past two decades important changes in the epidemiology and treatment of abdominal aortic aneurysms (AAAs) have occurred. The introduction of endovascular aortic repair (EVAR)
      • Volodos N.L.
      • Karpovich I.P.
      • Troyan V.I.
      • Kalashnikova Yu V.
      • Shekhanin V.E.
      • Ternyuk N.E.
      • et al.
      Clinical experience of the use of self-fixing synthetic prostheses for remote endoprosthetics of the thoracic and the abdominal aorta and iliac arteries through the femoral artery and as intraoperative endoprosthesis for aorta reconstruction.
      • Parodi J.C.
      • Palmaz J.C.
      • Barone H.D.
      Transfemoral intraluminal graft implantation for abdominal aortic aneurysms.
      has made it possible to offer surgical treatment to patients who are not optimal candidates for open aortic repair (OR).
      • Moll F.L.
      • Powell J.T.
      • Fraedrich G.
      • Verzini F.
      • Haulon S.
      • Waltham M.
      • et al.
      Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery.
      • Biancari F.
      • Catania A.
      • D'Andrea V.
      Elective endovascular vs. open repair for abdominal aortic aneurysm in patients aged 80 years and older: Systematic review and meta-analysis.
      With improved perioperative care
      • Papia G.
      • Klein D.
      • Lindsay T.F.
      Intensive care of the patient following open abdominal aortic surgery.
      and centralization of AAA interventions,
      • Swedvasc
      Annual reports from the Swedish vascular register 2015.
      outcome has steadily improved.
      • Wanhainen A.
      • Bylund N.
      • Bjorck M.
      Outcome after abdominal aortic aneurysm repair in Sweden 1994–2005.
      • Mani K.
      • Bjorck M.
      • Wanhainen A.
      Changes in the management of infrarenal abdominal aortic aneurysm disease in Sweden.
      Screening for AAA has been proven effective from a clinical and health economic perspective,
      • Lindholt J.S.
      • Juul S.
      • Fasting H.
      • Henneberg E.W.
      Cost-effectiveness analysis of screening for abdominal aortic aneurysms based on five year results from a randomised hospital based mass screening trial.
      • Ashton H.A.
      • Buxton M.J.
      • Day N.E.
      • Kim L.G.
      • Marteau T.M.
      • Scott R.A.
      • et al.
      The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: A randomised controlled trial.
      and a screening program targeting 65-year-old men was introduced in Sweden in 2006,
      • Wanhainen A.
      • Bjorck M.
      The Swedish experience of screening for abdominal aortic aneurysm.
      reaching nationwide coverage in 2015.
      • Svensjo S.
      • Bjorck M.
      • Wanhainen A.
      Update on screening for abdominal aortic aneurysm: a topical review.
      Similar programs were launched in the UK and United States.
      • Stather P.W.
      • Dattani N.
      • Bown M.J.
      • Earnshaw J.J.
      • Lees T.A.
      International variations in AAA screening.
      Furthermore, the prevalence of the disease has fallen, partly because of changing smoking habits.
      • Svensjo S.
      • Bjorck M.
      • Gurtelschmid M.
      • Djavani Gidlund K.
      • Hellberg A.
      • Wanhainen A.
      Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease.
      These changes affect the epidemiology of AAA repair, which have implications on patient care and the optimal provision of vascular surgical services. The Swedish vascular registry (Swedvasc), with its high validity,
      • Venermo M.
      • Lees T.
      International vascunet validation of the Swedvasc registry.
      • Troeng T.
      • Malmstedt J.
      • Bjorck M.
      External validation of the Swedvasc registry: a first-time individual cross-matching with the unique personal identity number.
      in combination with the Swedish Population Registry, which provides 100% accurate mortality data, offers a great opportunity to monitor AAA repair epidemiology on a national level.
      The aim of this paper was to study the AAA repair epidemiology in Sweden 1994–2014, with focus on recent trends.

      Materials and Methods

      All primary AAA interventions performed during the period 1994–2014 were identified in the Swedvasc registry. Re-do procedures, duplicate entries, patients without a Swedish personal identification number (PIN), and patients <50 years of age were excluded. Data were cross-checked for mortality against the Swedish Population Registry in August 2015.
      Preoperative comorbidities registered in Swedvasc were diabetes (treated by diet, per oral medication, or insulin), pulmonary disease (any diagnosed pulmonary disease), cerebrovascular disease (stroke or transient ischemic attack), renal impairment (serum creatinine ≥ 150 mmol/L or renal replacement therapy), and heart disease (history of myocardial infarction, angina pectoris, heart failure, coronary bypass surgery, heart valve surgery, or atrial fibrillation). After May 2008, atrial fibrillation was not considered a cardiac comorbidity in Swedvasc. A nationwide AAA screening program targeting 65-year-old men was gradually introduced in Sweden 2006–2015. From 2010 it is recorded in Swedvasc if an AAA undergoing repair is detected by screening. Data were extrapolated and assumed a linear increase in screening-detected AAAs operated on from 2006 to 2010.
      Intact AAA repair was defined as any AAA operated on without any signs of rupture regardless of elective or urgent repair. Data for intact AAA and ruptured AAA were analyzed separately. Based on a predefined protocol for data analysis, data were calculated overall and for three age subgroups (50–64 years, 65–79 years, and ≥ 80 years), and for four time periods (1994–1999, 2000–2004, 2005–2009, and 2010–2014). Age- and sex-specific population data for each subgroup and overall (Swedish population ≥ 50 years) were obtained from Statistics Sweden.
      • Statistics Sweden
      Population by age and gender 1860–2014 [Befolkning efter ålder och kön år 1860–2014].

      Statistical analysis

      Proportions were compared using the chi-square test. Changes in proportions over time were assessed using the chi square test for trend. Normally distributed data were compared using one-way ANOVA. Histograms were used to assess normality. Long-term survival was calculated using Kaplan–Meier analysis and the log rank test was used to compare groups. To compensate for multiple testing p < .010 was considered significant. Ninety-nine percent confidence intervals (CI) for proportions were calculated with the Wald approximation. Calculations were made using SPSS version 22.0 (IBM, Armonk, NY, USA) and GraphPad Prism 6 (Graphpad software, La Jolla, CA, USA).

      Ethics approval

      The study was approved by the Regional Ethics Board of Uppsala (2014/078) and by the Swedvasc review board. According to the rules of the Swedvasc registry, informed consent is required from each patient or relative prior to registration, except for fatal cases that are exempted from informed consent according to Swedish law.

      Results

      A total of 15,268 intact AAA repairs and 5,907 ruptured AAA were identified. The repair incidence was 21.9 per 100,000 ≥ 50 years for intact AAA, and 8.5 per 100,000 for ruptured AAA. Baseline characteristic are shown in Table 1 and 30-day mortality in Table 2.
      Table 1Patient characteristics and incidence rate for intact AAA repair (iAAA) and ruptured AAA repair (rAAA).
      iAAA1994–19992000–20042005–20092010–2014Trendp
      Chi-square test for trend.
      Age
      Age is reported with mean value.
      (years)
      71.2 (70.9–71.5)71.9 (71.5–72.2)72.2 (71.9–72.5)72.5 (72.2–72.7)< .001
      ANOVA.
      Male (%)83.3 (81.7–85)82.4 (80.6–84.1)81.5 (79.9–83.1)84.6 (83.2–85.9).153
      Diabetes (%)6.6 (5.4–7.7)8.8 (7.4–10.1)11.1 (9.8–12.5)13.0 (11.7–14.2)< .001
      Current smoker (%)52.7 (50.3–55.1)46.1 (43.6–48.6)46.6 (44.4–48.8)30.0 (28.1–31.8)< .001
      Cerebrovascular disease (%)13.5 (11.9–15.1)14.9 (13.2–16.6)15.0 (13.5–16.6)12.8 (11.5–14.1).257
      Heart disease
      The definition of cardiac disease was changed in the Swedvasc registry in 2008. See Methods.
      (%)
      54.6 (52.4–56.9)54.3 (51.9–56.6)49.3 (47.2–51.5)39.4 (37.5–41.2)< .001
      Hypertension (%)50.9 (48.6–53.2)59.4 (57.0–61.7)72.0 (70.1–73.9)78.6 (77.0–80.1)< .001
      Pulmonary disease (%)17.3 (15.6–19.1)18.5 (16.7–20.4)22.4 (20.6–24.2)22.9 (21.3–24.5)< .001
      Renal disease (%)10.0 (8.6–11.4)10.1 (8.7–11.6)10.8 (9.5–12.1)5.3 (4.4–6.1)< .001
      ≥ 80 years (%)9.5 (8.2–10.8)14.4 (12.8–16.0)17.3 (15.7–18.9)18.3 (16.9–19.7)< .001
      EVAR (%)3.4 (2.6–4.2)20.1 (18.3–22.0)44.5 (42.4–46.5)57.5 (55.7–59.3)< .001
      Rate per 100.000 ≥ 50 years18.4 (17.6–19.2)19.1 (18.3–20)22.6 (21.7–23.5)27.3 (26.3–28.3)< .001
      Rate per 100.000 men ≥ 50 years33.2 (31.6–34.8)33.7 (32.0–35,4)39.0 (37.2–40.7)48.4 (46.4–50.3)< .001
      Rate per 100.000 women ≥ 50 years5.7 (5.1–6.3)6.3 (5.6–7.0)7.9 (7.2–8.7)8.1 (7.3–8.8)< .001
      rAAA
      Age
      Age is reported with mean value.
      (years)
      72.8 (72.3–73.3)73.8 (73.3–74.3)73.8 (73.3–74.4)75.3 (74.7–75.9).002
      ANOVA.
      Male (%)86.3 (84.1–88.4)85.4 (83.1–87.7)80.3 (77.6–83.0)79.6 (76.6–82.5)< .001
      Diabetes (%)6.8 (5.1–8.5)7.9 (6.0–9.8)9.9 (7.8–12.0)13.4 (10.8–16.0)< .001
      Current smoker (%)51.9 (47.8–56.1)44.2 (40.1–48.2)51.3 (46.8–55.9)45.1 (39.9–50.3).105
      Cerebrovascular disease (%)14.8 (12.4–17.3)15.8 (13.2–18.4)15.3 (12.7–17.9)14.8 (12.0–17.6).948
      Heart disease
      The definition of cardiac disease was changed in the Swedvasc registry in 2008. See Methods.
      (%)
      50.4 (47.1–53.8)54.1 (50.7–57.6)47.3 (43.8–50.9)38.9 (35.0–42.7)< .001
      Hypertension (%)48.2 (44.8–51.7)53.1 (49.5–56.6)65.6 (62.1–69.0)72.0 (68.4–75.6)< .001
      Pulmonary disease (%)17.4 (14.8–20.0)18.4 (15.7–21.2)22.6 (19.6–25.7)23.1 (19.7–26.4)< .001
      Renal disease (%)11.8 (9.5–14.0)12.2 (9.8–14.5)15.6 (13.0–18.3)18.0 (15.0–21.1)< .001
      ≥ 80 years (%)19.1 (16.7–21.6)26.8 (23.9–29.7)26.6 (23.6–29.6)33.3 (29.8–36.7)< .001
      EVAR (%)0.1 (0.0–0.2)4.1 (2.8–5.4)15.4 (12.9–17.8)29.8 (26.5–33.2)< .001
      Rate per 100.000 ≥ 50 years9.2 (8.7–9.8)9.4 (8.7–10.0)8.4 (7.9–9.0)6.9 (6.4–7.4)< .001
      Rate per 100.000 men ≥ 50 years17.3 (16.1–18.4)17.1 (15.9–18.3)14.3 (13.2–15.4)11.5 (10.6–12.4)< .001
      Rate per 100.000 women ≥ 50 years2.4 (2.0–2.8)2.6 (2.1–3.0)3.2 (2.7–3.6)2.7 (2.3–3.1).031
      Note. Values in parenthesis are 99% confidence intervals. EVAR = endovascular aortic repair.
      a Age is reported with mean value.
      b The definition of cardiac disease was changed in the Swedvasc registry in 2008. See Methods.
      c Chi-square test for trend.
      d ANOVA.
      Table 2Thirty day mortality (%) for intact and ruptured abdominal aortic aneurysm (AAA) repair by surgical techniques, age and gender.
      iAAA1994–19992000–20042005–20092010–2014Trendp
      Chi-square test for trend.
      All4.7 (3.7–5.6)3.1 (2.3–3.9)2.5 (1.9–3.2)1.7 (1.2–2.1)< .001
      EVAR2.6 (0.0–6.5)2.2 (0.7–3.7)1.9 (1.1–2.8)0.9 (0.4–1.3).001
      Open repair4.7 (3.8–5.7)3.3 (2.4–4.3)3.0 (2.0–3.9)2.7 (1.8–3.7)< .001
      50–64 years2.5 (0.8–4.2)1.6 (0.2–3.1)0.6 (0.0–1.4)1.2 (0.0–2.4).028
      65–79 years4.6 (3.5–5.7)3.2 (2.2–4.2)2.5 (1.7–3.3)1.7 (1.1–2.2)< .001
      ≥ 80 years9.0 (4.9–13.1)4.5 (1.9–7.0)4.5 (2.4–6.6)2.0 (0.8–3.2)< .001
      Female6.7 (4.0–9.4)4.0 (1.8–6.2)3.8 (1.9–5.6)2.5 (1.0–4.0)< < .001
      Male4.2 (3.3–5.2)2.9 (2.1–3.8)2.2 (1.6–2.9)1.5 (1.0–2.0)< .001
      rAAA
      All38.3 (35.2–41.3)32.9 (29.8–36)27.9 (24.9–31.0)28.2 (24.9–31.5)< .001
      EVAR
      Only one endovascular repair occurred in the first cohort. This was excluded from the trend analysis.
      15.9 (4.0–27.7)18.1 (11.4–24.8)22.2 (16.6–27.8).137
      Open repair38.2 (35.2–41.3)33.6 (30.4–36.8)29.7 (26.3–33.1)30.7 (26.7–34.8)< .001
      50–64 years21.2 (14.4–27.9)16.3 (9.7–22.8)12.7 (7.0–18.4)20.8 (11.6–29.9).333
      65–79 years38.3 (34.5–42.0)29.2 (25.3–33.1)25.4 (21.5–29.3)24.6 (20.4–28.8)< .001
      ≥ 80 years50.9 (43.8–58.1)49.6 (43.3–56.0)42.6 (36.1–49.1)36.7 (30.5–42.8)< .001
      Female43.6 (35.2–51.9)43.0 (34.5–51.6)35.2 (27.9–42.5)34.4 (26.7–42.1).011
      Male37.4 (34.2–40.7)31.2 (27.9–34.5)26.1 (22.8–29.5)26.6 (23.0–30.2)< .001
      Note. Values in parentheses are 99% confidence intervals. iAAA = intact abdominal aortic aneurysm; rAAA = ruptured abdominal aortic aneurysm.
      a Chi-square test for trend.
      b Only one endovascular repair occurred in the first cohort. This was excluded from the trend analysis.

      Intact AAA repair

      The incidence of intact AAA repair increased by 48.5% (99% CI 41.1–55.8) from the first to the last study period. The increase in intact AAA repair incidence was significant in all age groups (p < .001; see Fig. 2 and Table 1). The increase was most prominent among octogenarians where repair incidence inclined 184% (99% CI 144.8–223.5) from 12.7 out of 100,000 ≥ 80 years in 1994–1999 to 36.0 out of 100,000 ≥ 80 years in 2010–2014. However, during the last time period the repair incidence stabilized (incidence 2010–2014 chi square for trend p = .062). During the same period, an increasing number of screening-detected AAAs were operated on, constituting 18.6% (99% CI 17.2–20.1) of all intact AAA repairs during the last period (Fig. 1). The proportion of repairs performed with EVAR increased continuously (Fig. 2, Appendix I) from 3.4% (99% CI 2.6–4.2) 1994–1999 to 57.5% (99% CI 55.7–59.3) in 2010–2014. For patients ≥ 80 years EVAR was used in 79,7% (99% CI 76.3–83.2) of intact AAA repair in 2010–2014.
      Figure 1
      Figure 1Incidence of repair of (A) intact and (B) ruptured abdominal aortic aneurysms (AAA) over time per 100,000 Swedish residents ≥ 50 years of age. EVAR, endovascular repair.
      Figure 2
      Figure 2(A) Incidence of open and endovascular repair (EVAR) of intact abdominal aortic aneurysms (AAA) in different age groups over time, per 100,000 Swedish residents ≥ 50 years of age. (B) Incidence of open repair and EVAR in ruptured AAAs in different age groups over time.
      Despite progressively older patients, short- and long-term outcome improved over time, most prominent among octogenarians (Table 1, Table 2, Table 3). Although 30-day mortality in octogenarians was two to three times higher than in younger patients during the first three time periods, there was no remaining difference between age groups in the last time period (Table 2) (p = .246). The prevalence of current smokers decreased and the comorbidity spectrum changed significantly; with fewer patients having a history of heart disease, and more patients were being treated for hypertension and having a history of diabetes, and pulmonary disease (Table 1, Table 2).
      Table 3Mid- and long-term survival after repair of intact abdominal aortic aneurysm and ruptured abdominal aortic aneurysm.
      iAAA1994–19992000–20042005–20092010–2014Trend
      90 day survival94.0 (93.0–95.0)95.5 (94.5–96.5)96.0 (95.2–96.8)97.1 (96.6–97.6)
      1 year survival90.2 (88.9–91.5)92.2 (90.9–93.5)92.2 (91.2–93.2)94.1 (93.3–94.9)
      5 year survival67.3 (65.2–69.4)72.4 (70.3–74.5)73.2 (71.4–75.0)75.3 (72.7–77.9)
      rAAA
      90 day survival57.4 (54.3–60.5)63.6 (60.5–66.7)67.8 (64.7–70.9)67.2 (63.9–70.5)
      1 year survival54.0 (50.9–57.1)60.0 (56.7–63.3)64.0 (60.7–67.3)62.4 (58.8–66.0)
      5 year survival39.3 (36.2–42.4)44.1 (40.8–47.4)50.0 (46.7–53.3)47.0 (42.1–51.9)
      Note. p < 0.001 for both iAAA and rAAA, log rank test. iAAA = intact abdominal aortic aneurysm; rAAA = ruptured abdominal aortic aneurysm.

      Ruptured AAA repair

      During the second half of the study period the ruptured AAA repair incidence decreased significantly overall, among men and among patients < 80 years (p < .001), but was stable among women. For octogenarians there was a significant increase in repair incidence (p = 0.007). The utilization of EVAR slowly increased over time, most prominent in the ≥ 80 years group (p < .001) (Figure 1, Figure 2, Table 1, and Appendix I).
      Despite higher age (Table 1), short- and long-term outcome improved during the three first time periods and stabilized during the last time period (Table 3); however, the proportion of octogenarians undergoing ruptured AAA repair increased from 26.6% to 33.3% between the two last periods (Table 1, Table 2, Table 3 and Fig. 3). The prevalence of current smokers and the comorbidity spectrum changed in a similar way as for intact AAA repair (Table 1).
      Figure 3
      Figure 3Kaplan–Meier analysis of crude survival after repair of (A) intact abdominal aortic aneurysm (AAA) and (B) ruptured AAA.

      Discussion

      The benefit of the highly validated Swedish Vascular Registry is that it gives the possibility to study AAA repair epidemiology in a nationwide real-world situation where patient selection, operation method, and outcome are the result of everyday clinical decisions based on the available resources, surgeons’ experience, and judgment and geographical factors. In this study of AAA repair epidemiology over a 20-year period some important new trends were found: (1) the longstanding increase in incidence of intact AAA repair has now come to an end, although the incidence of ruptured AAA repair continues to decrease, and (2) short- and long-term outcome continued to improve after intact AAA repair, but it has stabilized after ruptured AAA repair. In summary, the total AAA surgical workload has begun to decrease, and it is the decline in resource-intensive ruptured AAA repair that is the main factor in this process. This marked shift in the epidemiology of AAA repair is important for healthcare planning and allocation of resources.
      The marked increase in intact AAA repair incidence up till 2010 followed by stabilization, or even a decrease in incidence (if AAAs detected by screening are excluded), is likely explained by a combination of factors. The effect of the increased use of EVAR and treatment of increasing number of octogenarians, and more recently the introduction of screening, is counterbalanced by the effect of a reduced prevalence of the disease. A point has now been reached where the reduced prevalence of the disease evens out the other factors for the first time.
      Similarly, the reduced prevalence of the disease combined with the longstanding increase in prophylactic AAA repair likely explains the marked reduction in ruptured AAA repair incidence.
      • Svensjo S.
      • Bjorck M.
      • Gurtelschmid M.
      • Djavani Gidlund K.
      • Hellberg A.
      • Wanhainen A.
      Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease.
      • Anjum A.
      • Powell J.T.
      Is the incidence of abdominal aortic aneurysm declining in the 21st century? Mortality and hospital admissions for England & Wales and Scotland.
      This trend has previously been observed both in Sweden and in other countries.
      • Wanhainen A.
      • Bylund N.
      • Bjorck M.
      Outcome after abdominal aortic aneurysm repair in Sweden 1994–2005.
      • Mani K.
      • Bjorck M.
      • Wanhainen A.
      Changes in the management of infrarenal abdominal aortic aneurysm disease in Sweden.
      • Wendt K.
      • Kristiansen R.
      • Krohg-Sorensen K.
      • Gregersen F.A.
      • Fosse E.
      Trends in abdominal aortic and iliac aneurysm repairs in Norway from 2001 to 2013.
      • Mohan P.P.
      • Rozenfeld M.
      • Kane R.A.
      • Calandra J.D.
      • Hamblin M.H.
      Nationwide trends in abdominal aortic aneurysm repair and use of endovascular repair in the emergency setting.
      • Mureebe L.
      • Egorova N.
      • Giacovelli J.K.
      • Gelijns A.
      • Kent K.C.
      • McKinsey J.F.
      National trends in the repair of ruptured abdominal aortic aneurysms.
      The lack of reduction of ruptured AAA repair in the octogenarian population could be related to a continuously increasing use of EVAR in ruptures, which allows repair in patients previously deemed unfit for open ruptured AAA repair. Interestingly, no reduction in ruptured AAA repair rate was seen in women, a population not included in the Swedish screening program. Owing to a low prevalence, population screening of women is currently not recommended,
      • Svensjo S.
      • Bjorck M.
      • Wanhainen A.
      Current prevalence of abdominal aortic aneurysm in 70-year-old women.
      although a more selective high-risk screening strategy, targeting for example smoking women, is an ongoing discussion.
      • Svensjo S.
      • Bjorck M.
      • Wanhainen A.
      Update on screening for abdominal aortic aneurysm: a topical review.
      Associated with the rapid increase in the use of EVAR two other observations can be made. Firstly, the 30-day mortality has decreased by 64%, from 4.7% in 1994–1999 to 1.7% in 2010–2014. This compares favorably in an international perspective, where intact AAA repair mortality was reported at 2.0–5.0% in an international registry-based analysis.
      • Mani K.
      • Venermo M.
      • Beiles B.
      • Menyhei G.
      • Altreuther M.
      • Loftus I.
      • et al.
      Regional differences in case mix and peri-operative outcome after elective abdominal aortic aneurysm repair in the Vascunet database.
      The improved short-term outcome is sustained for at least 5 years as indicated by the improving long-term survival. Secondly, there is no longer a significantly higher 30-day mortality after intact AAA repair among octogenarians than in younger patients. Although good results of open repair in octogenarians have been reported,
      • Dainese L.
      • Barili F.
      • Spirito R.
      • Topkara V.K.
      • Pompilio G.
      • Trezzi M.
      • et al.
      Abdominal aortic aneurysm repair in octogenarians: Outcomes and predictors.
      this is likely related to the preferential use of EVAR for treatment of octogenarians. These findings contrast to the EVAR 2 trial
      • Greenhalgh R.M.
      • Brown L.C.
      • Powell J.T.
      • Thompson S.G.
      • Epstein D.
      United Kingdom EVAR Trial Investigators
      Endovascular repair of aortic aneurysm in patients physically ineligible for open repair.
      that randomized patients considered unfit for open repair to either EVAR or conservative treatment and failed to show any survival benefit in the EVAR group, possibly because of the unexpectedly high 30-day mortality rate (7.3%) after EVAR. In the present study the 30-day mortality rate was only 2.0% for octogenarians (of which 79.7% treated with EVAR). On the other hand, a meta-analysis of six observational studies showed significant survival benefits in octogenarians treated with EVAR compared with open repair.
      • Biancari F.
      • Catania A.
      • D'Andrea V.
      Elective endovascular vs. open repair for abdominal aortic aneurysm in patients aged 80 years and older: Systematic review and meta-analysis.
      Against this background one can make the case that the clinical decisions to use EVAR to treat older and sicker patients have been sound.
      For ruptured AAA repair perioperative mortality improved up to the 2005–2009 cohort (a 28% reduction in 30-day mortality from 1994–1999 to 2005–2009) and then stabilized. This result is similar to other international reports.
      • Bastos Goncalves F.
      • Ultee K.H.
      • Hoeks S.E.
      • Stolker R.J.
      • Verhagen H.J.
      Life expectancy and causes of death after repair of intact and ruptured abdominal aortic aneurysms.
      Also long-term survival improved in the first three periods and stabilized thereafter, indicating that the change in short-term survival is sustained over time. These improvements were seen in parallel with an ever-increasing proportion of repairs being performed in octogenarians and a much-increased uptake of EVAR. This is of particular interest as four randomized controlled trials (RCTs)
      • Desgranges P.
      • Kobeiter H.
      • Katsahian S.
      • Bouffi M.
      • Gouny P.
      • Favre J.P.
      • et al.
      Editor's Choice - ECAR (Endovasculaire ou Chirurgie dans les Anevrysmes aorto-iliaques Rompus): A French randomized controlled trial of endovascular versus open surgical repair of ruptured aorto-iliac aneurysms.
      • Hinchliffe R.J.
      • Bruijstens L.
      • MacSweeney S.T.
      • Braithwaite B.D.
      A randomised trial of endovascular and open surgery for ruptured abdominal aortic aneurysm - results of a pilot study and lessons learned for future studies.
      • IMPROVE Trial Investigators
      Endovascular strategy or open repair for ruptured abdominal aortic aneurysm: one-year outcomes from the IMPROVE randomized trial.
      • Reimerink J.J.
      • Hoornweg L.L.
      • Vahl A.C.
      • Wisselink W.
      • van den Broek T.A.
      • Legemate D.A.
      • et al.
      Endovascular repair versus open repair of ruptured abdominal aortic aneurysms: A multicenter randomized controlled trial.
      and one individual-patient meta-analysis
      • Sweeting M.J.
      • Balm R.
      • Desgranges P.
      • Ulug P.
      • Powell J.T.
      • Ruptured Aneurysm T.
      Individual-patient meta-analysis of three randomized trials comparing endovascular versus open repair for ruptured abdominal aortic aneurysm.
      failed to show any benefit of EVAR in patients suffering from ruptured AAA. However, the data suggests that in an unselected patient population the approach to preferentially perform EVAR in the elderly has been successful also for ruptured AAA. On the other hand, the stabilization of outcome suggests that with the treatment options at hand today it is no longer possible to operate on increasingly older patients suffering from ruptured AAA and continue to improve survival rate. But considering the bleak prognosis of an untreated ruptured AAA, and a 63% chance of perioperative survival in an elderly patient, an active treatment approach seems fair in patients who agree to surgical attempt. This approach is supported by a study from Switzerland, where it was concluded elderly patients who survived surgery for a ruptured AAA had a near normal long-term prognosis.
      • Opfermann P.
      • von Allmen R.
      • Diehm N.
      • Widmer M.K.
      • Schmidli J.
      • Dick F.
      Repair of ruptured abdominal aortic aneurysm in octogenarians.
      The improving survival rates after intact AAA repair has led to a discussion on lowering the threshold diameter for AAA repair. In a recent publication, Karthikesalingam et al.
      • Karthikesalingam A.
      • Vidal-Diez A.
      • Holt P.J.
      • Loftus I.M.
      • Schermerhorn M.L.
      • Soden P.A.
      • et al.
      Thresholds for abdominal aortic aneurysm repair in England and the United States.
      observed a significantly lower AAA-related mortality in the United States compared with the UK, which was linked to a lower size threshold for AAA repair, and higher rate of EVAR, in the United States. No benefit of a threshold for repair < 5.5 cm (mean 4.6 cm) was, however, found in two recent RCTs investigating early EVAR versus surveillance, despite an operative mortality rate of only 0.6% observed. This was due to a very low rupture rate in the surveillance group.
      • Cao P.
      • De Rango P.
      • Verzini F.
      • Parlani G.
      • Romano L.
      • Cieri E.
      • et al.
      Comparison of surveillance versus aortic endografting for small aneurysm repair (CAESAR): results from a randomised trial.
      • Ouriel K.
      • Clair D.G.
      • Kent K.C.
      • Zarins C.K.
      Positive impact of endovascular options for treating aneurysms early I. Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms.
      In the present report the observed 30-day mortality after intact AAA repair was overall 1.7% and 0.9% after EVAR, suggesting that the benefit of repair of small aneurysms at low risk of rupture is likely to be outweighed by the risk of repair. In an international comparison, the rate of intact small AAA repair in Sweden was on the same level as other countries with population-based reimbursement system (e.g., other Scandinavian countries), and lower than in countries with a fee-for-service healthcare system (e.g., Australia and United States).
      • Beck A.W.
      • Sedrakyan A.
      • Mao J.
      • Venermo M.
      • Faizer R.
      • Debus S.
      • et al.
      Variations in abdominal aortic aneurysm care: A report from the International consortium of vascular registries.
      During the study period there has been a centralization of AAA surgery in Sweden,
      • Swedvasc
      Annual reports from the Swedish vascular register 2015.
      where a few very small centers have stopped performing AAA repair. At the same time the number of centers able to preform EVAR has increased. These two trends are likely to contribute to the lower mortality rates after both intact and ruptured AAA repair in Sweden. Interestingly, a recent study testing the hypothesis that centers with a primary EVAR strategy for ruptured AAA would have better results failed to show any such differences.
      • Gunnarsson K.
      • Wanhainen A.
      • Djavani Gidlund K.
      • Bjorck M.
      • Mani K.
      Endovascular versus open repair as primary strategy for ruptured abdominal aortic aneurysm: A national population-based study.
      From a health policy perspective, the findings of the current report indicate that the introduction of a national AAA screening program among men is not likely to result in a significant increase in AAA repair workload over time. It is important, however, to acknowledge that this report only included primary AAA repairs, while re-intervention and secondary interventions were excluded. The increasing uses of EVAR results in a significant need for resources for postoperative surveillance and re-intervention,
      • Giles K.A.
      • Landon B.E.
      • Cotterill P.
      • O'Malley A.J.
      • Pomposelli F.B.
      • Schermerhorn M.L.
      Thirty-day mortality and late survival with reinterventions and readmissions after open and endovascular aortic aneurysm repair in Medicare beneficiaries.
      which will have an impact on the overall AAA-related operative workload. Additionally, the increasingly important role of EVAR in treatment of intact- and ruptured AAA patients with excellent results suggest a need for harmonization of vascular services, where vascular centers preferably should have 24/7 coverage for both open and endovascular repair of AAA. Currently, significant variations are present in EVAR availability and usage both between centers within one country, and between nations.
      • Gunnarsson K.
      • Wanhainen A.
      • Djavani Gidlund K.
      • Bjorck M.
      • Mani K.
      Endovascular versus open repair as primary strategy for ruptured abdominal aortic aneurysm: A national population-based study.
      • Mani K.
      • Lees T.
      • Beiles B.
      • Jensen L.P.
      • Venermo M.
      • Simo G.
      • et al.
      Treatment of abdominal aortic aneurysm in nine countries 2005–2009: A vascunet report.

      Limitations

      Patients who are declined surgical repair are not registered in Swedvasc registry and this study is unable to report the rate of AAAs treated conservatively. The registry contains no information regarding why EVAR was chosen over open repair or vice versa. It is likely that the basis for the choice of operation method (i.e., the aneurysm anatomy, severe comorbidity) affects outcome, which is why this analysis was not aimed at assessing differences in outcome based on surgical technique. The change of definition of heart disease (see methods) in Swedvasc and the inability to register if an AAA was discovered in screening until 2010, even though the screening program started in 2006, constitutes other potential sources of error.

      Conclusions

      In this nationwide analysis of AAA repair epidemiology in Sweden, a halt in the increase in incidence of intact AAA repair could be identified for the first time. This trend-break occurred despite increasing rate of EVAR, a continued increase in the surgical treatment of octogenarians, and an increasing number of screening-detected aneurysms being operated. The incidence of ruptured AAA repair has steadily declined since 2000, likely because of a combination of increased prophylactic intact AAA repair activity and decreased AAA prevalence. The perioperative and long-term survival after intact AAA repair continued to improve, especially in the elderly population. Thanks to the increasing use of EVAR in octogenarians, the perioperative survival after intact AAA repair was equally good in elderly patients when compared with younger patients. These findings have implications in the planning of provision of vascular surgical services in the future, where further centralization may be required due to reduction in AAA repair activity, specially considering open surgery.

      Acknowledgments

      The Swedvasc Steering Committee generously permitted us to analyze the database. Joakim Nordanstig (Chairman), Erik Wellander, Joachim Starck, Birgitta Sigvant, Katarina Björses, Lena Blomgren, Magnus Jonsson, Ann Wigelius. Senior advisory board: David Bergqvist, Lars Norgren, Thomas Troëng.

      Conflict of Interest

      None.

      Funding

      None.

      Appendix A. Supplementary data

      The following is the supplementary data related to this article:

      References

        • Volodos N.L.
        • Karpovich I.P.
        • Troyan V.I.
        • Kalashnikova Yu V.
        • Shekhanin V.E.
        • Ternyuk N.E.
        • et al.
        Clinical experience of the use of self-fixing synthetic prostheses for remote endoprosthetics of the thoracic and the abdominal aorta and iliac arteries through the femoral artery and as intraoperative endoprosthesis for aorta reconstruction.
        Vasa Suppl. 1991; 33: 93-95
        • Parodi J.C.
        • Palmaz J.C.
        • Barone H.D.
        Transfemoral intraluminal graft implantation for abdominal aortic aneurysms.
        Ann Vasc Surg. 1991; 5: 491-499
        • Moll F.L.
        • Powell J.T.
        • Fraedrich G.
        • Verzini F.
        • Haulon S.
        • Waltham M.
        • et al.
        Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery.
        Eur J Vasc Endovasc Surg. 2011; 41: S1-S58
        • Biancari F.
        • Catania A.
        • D'Andrea V.
        Elective endovascular vs. open repair for abdominal aortic aneurysm in patients aged 80 years and older: Systematic review and meta-analysis.
        Eur J Vasc Endovasc Surg. 2011; 42: 571-576
        • Papia G.
        • Klein D.
        • Lindsay T.F.
        Intensive care of the patient following open abdominal aortic surgery.
        Curr Opin Crit Care. 2006; 12: 340-345
        • Swedvasc
        Annual reports from the Swedish vascular register 2015.
        2015-12-21 (Retrieved March 14, 2017, from http://www.ucr.uu.se/swedvasc/)
        • Wanhainen A.
        • Bylund N.
        • Bjorck M.
        Outcome after abdominal aortic aneurysm repair in Sweden 1994–2005.
        Br J Surg. 2008; 95: 564-570
        • Mani K.
        • Bjorck M.
        • Wanhainen A.
        Changes in the management of infrarenal abdominal aortic aneurysm disease in Sweden.
        Br J Surg. 2013; 100: 638-644
        • Lindholt J.S.
        • Juul S.
        • Fasting H.
        • Henneberg E.W.
        Cost-effectiveness analysis of screening for abdominal aortic aneurysms based on five year results from a randomised hospital based mass screening trial.
        Eur J Vasc Endovasc Surg. 2006; 32: 9-15
        • Ashton H.A.
        • Buxton M.J.
        • Day N.E.
        • Kim L.G.
        • Marteau T.M.
        • Scott R.A.
        • et al.
        The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: A randomised controlled trial.
        Lancet. 2002; 360: 1531-1539
        • Wanhainen A.
        • Bjorck M.
        The Swedish experience of screening for abdominal aortic aneurysm.
        J Vasc Surg. 2011; 53: 1164-1165
        • Svensjo S.
        • Bjorck M.
        • Wanhainen A.
        Update on screening for abdominal aortic aneurysm: a topical review.
        Eur J Vasc Endovasc Surg. 2014; 48: 659-667
        • Stather P.W.
        • Dattani N.
        • Bown M.J.
        • Earnshaw J.J.
        • Lees T.A.
        International variations in AAA screening.
        Eur J Vasc Endovasc Surg. 2013; 45: 231-234
        • Svensjo S.
        • Bjorck M.
        • Gurtelschmid M.
        • Djavani Gidlund K.
        • Hellberg A.
        • Wanhainen A.
        Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease.
        Circulation. 2011; 124: 1118-1123
        • Venermo M.
        • Lees T.
        International vascunet validation of the Swedvasc registry.
        Eur J Vasc Endovasc Surg. 2015; 50: 802-808
        • Troeng T.
        • Malmstedt J.
        • Bjorck M.
        External validation of the Swedvasc registry: a first-time individual cross-matching with the unique personal identity number.
        Eur J Vasc Endovasc Surg. 2008; 36: 705-712
        • Statistics Sweden
        Population by age and gender 1860–2014 [Befolkning efter ålder och kön år 1860–2014].
        Statistics Sweden, Stockholm2015
        • Anjum A.
        • Powell J.T.
        Is the incidence of abdominal aortic aneurysm declining in the 21st century? Mortality and hospital admissions for England & Wales and Scotland.
        Eur J Vasc Endovasc Surg. 2012; 43: 161-166
        • Wendt K.
        • Kristiansen R.
        • Krohg-Sorensen K.
        • Gregersen F.A.
        • Fosse E.
        Trends in abdominal aortic and iliac aneurysm repairs in Norway from 2001 to 2013.
        Eur J Vasc Endovasc Surg. 2015;
        • Mohan P.P.
        • Rozenfeld M.
        • Kane R.A.
        • Calandra J.D.
        • Hamblin M.H.
        Nationwide trends in abdominal aortic aneurysm repair and use of endovascular repair in the emergency setting.
        J Vasc Interv Radiol. 2012; 23: 338-344
        • Mureebe L.
        • Egorova N.
        • Giacovelli J.K.
        • Gelijns A.
        • Kent K.C.
        • McKinsey J.F.
        National trends in the repair of ruptured abdominal aortic aneurysms.
        J Vasc Surg. 2008; 48: 1101-1107
        • Svensjo S.
        • Bjorck M.
        • Wanhainen A.
        Current prevalence of abdominal aortic aneurysm in 70-year-old women.
        Br J Surg. 2013; 100: 367-372
        • Mani K.
        • Venermo M.
        • Beiles B.
        • Menyhei G.
        • Altreuther M.
        • Loftus I.
        • et al.
        Regional differences in case mix and peri-operative outcome after elective abdominal aortic aneurysm repair in the Vascunet database.
        Eur J Vasc Endovasc Surg. 2015; 49: 646-652
        • Dainese L.
        • Barili F.
        • Spirito R.
        • Topkara V.K.
        • Pompilio G.
        • Trezzi M.
        • et al.
        Abdominal aortic aneurysm repair in octogenarians: Outcomes and predictors.
        Eur J Vasc Endovasc Surg. 2006; 31: 464-469
        • Greenhalgh R.M.
        • Brown L.C.
        • Powell J.T.
        • Thompson S.G.
        • Epstein D.
        • United Kingdom EVAR Trial Investigators
        Endovascular repair of aortic aneurysm in patients physically ineligible for open repair.
        N Engl J Med. 2010; 362: 1872-1880
        • Bastos Goncalves F.
        • Ultee K.H.
        • Hoeks S.E.
        • Stolker R.J.
        • Verhagen H.J.
        Life expectancy and causes of death after repair of intact and ruptured abdominal aortic aneurysms.
        J Vasc Surg. 2016; 63: 610-616
        • Desgranges P.
        • Kobeiter H.
        • Katsahian S.
        • Bouffi M.
        • Gouny P.
        • Favre J.P.
        • et al.
        Editor's Choice - ECAR (Endovasculaire ou Chirurgie dans les Anevrysmes aorto-iliaques Rompus): A French randomized controlled trial of endovascular versus open surgical repair of ruptured aorto-iliac aneurysms.
        Eur J Vasc Endovasc Surg. 2015; 50: 303-310
        • Hinchliffe R.J.
        • Bruijstens L.
        • MacSweeney S.T.
        • Braithwaite B.D.
        A randomised trial of endovascular and open surgery for ruptured abdominal aortic aneurysm - results of a pilot study and lessons learned for future studies.
        Eur J Vasc Endovasc Surg. 2006; 32 (discussion 14–5): 506-513
        • IMPROVE Trial Investigators
        Endovascular strategy or open repair for ruptured abdominal aortic aneurysm: one-year outcomes from the IMPROVE randomized trial.
        Eur Heart J. 2015; 36: 2061-2069
        • Reimerink J.J.
        • Hoornweg L.L.
        • Vahl A.C.
        • Wisselink W.
        • van den Broek T.A.
        • Legemate D.A.
        • et al.
        Endovascular repair versus open repair of ruptured abdominal aortic aneurysms: A multicenter randomized controlled trial.
        Ann Surg. 2013; 258: 248-256
        • Sweeting M.J.
        • Balm R.
        • Desgranges P.
        • Ulug P.
        • Powell J.T.
        • Ruptured Aneurysm T.
        Individual-patient meta-analysis of three randomized trials comparing endovascular versus open repair for ruptured abdominal aortic aneurysm.
        Br J Surg. 2015; 102: 1229-1239
        • Opfermann P.
        • von Allmen R.
        • Diehm N.
        • Widmer M.K.
        • Schmidli J.
        • Dick F.
        Repair of ruptured abdominal aortic aneurysm in octogenarians.
        Eur J Vasc Endovasc Surg. 2011; 42: 475-483
        • Karthikesalingam A.
        • Vidal-Diez A.
        • Holt P.J.
        • Loftus I.M.
        • Schermerhorn M.L.
        • Soden P.A.
        • et al.
        Thresholds for abdominal aortic aneurysm repair in England and the United States.
        N Engl J Med. 2016; 375: 2051-2059
        • Cao P.
        • De Rango P.
        • Verzini F.
        • Parlani G.
        • Romano L.
        • Cieri E.
        • et al.
        Comparison of surveillance versus aortic endografting for small aneurysm repair (CAESAR): results from a randomised trial.
        Eur J Vasc Endovasc Surg. 2011; 41: 13-25
        • Ouriel K.
        • Clair D.G.
        • Kent K.C.
        • Zarins C.K.
        Positive impact of endovascular options for treating aneurysms early I. Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms.
        J Vasc Surg. 2010; 51: 1081-1087
        • Beck A.W.
        • Sedrakyan A.
        • Mao J.
        • Venermo M.
        • Faizer R.
        • Debus S.
        • et al.
        Variations in abdominal aortic aneurysm care: A report from the International consortium of vascular registries.
        Circulation. 2016; 134: 1948-1958
        • Gunnarsson K.
        • Wanhainen A.
        • Djavani Gidlund K.
        • Bjorck M.
        • Mani K.
        Endovascular versus open repair as primary strategy for ruptured abdominal aortic aneurysm: A national population-based study.
        Eur J Vasc Endovasc Surg. 2016; 51: 22-28
        • Giles K.A.
        • Landon B.E.
        • Cotterill P.
        • O'Malley A.J.
        • Pomposelli F.B.
        • Schermerhorn M.L.
        Thirty-day mortality and late survival with reinterventions and readmissions after open and endovascular aortic aneurysm repair in Medicare beneficiaries.
        J Vasc Surg. 2011; 53 (6–12.3.e1)
        • Mani K.
        • Lees T.
        • Beiles B.
        • Jensen L.P.
        • Venermo M.
        • Simo G.
        • et al.
        Treatment of abdominal aortic aneurysm in nine countries 2005–2009: A vascunet report.
        Eur J Vasc Endovasc Surg. 2011; 42: 598-607

      Comments

      Commenting Guidelines

      To submit a comment for a journal article, please use the space above and note the following:

      • We will review submitted comments as soon as possible, striving for within two business days.
      • This forum is intended for constructive dialogue. Comments that are commercial or promotional in nature, pertain to specific medical cases, are not relevant to the article for which they have been submitted, or are otherwise inappropriate will not be posted.
      • We require that commenters identify themselves with names and affiliations.
      • Comments must be in compliance with our Terms & Conditions.
      • Comments are not peer-reviewed.