Class 2 Advisor: Alberto Freitas

1. Introdução à Medicina II Abdominal Aortic Aneurysm in Portuguese Mainland State Hospitals: Regional Variations of Treatment Choice and In-Hospital Mortality Ana Catarina Rodrigues, Carolina Rodrigues, Catarina Cruz, Diogo Costa, Isabel Vazquez, Joana Garcia, Joana Rei, João Paulo Carvalho, José João Monteiro, José Pedro Vale, Lúcia Vieira, Manuel Neiva de Sousa, Marisa Martins and Ricardo Coutinho Class 2 Advisor: Alberto Freitas

2. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

3. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

4. Background • Convention: an infrarenal aorta of 3 cm in diameter or larger is considered aneurysmal3 Aorta with large abdominal aneurysm Normal aorta 1 Upchurch (2006) Am Fam Physician, 73(7): 1198-204 2 Lederle (1997) J Vasc Surg, 26(4): 595-601 • Abdominal Aortic Aneurysm (AAA) • Permanent focal dilatation of the abdominal artery below the kidneys (infrarenal) to at least1,5 times its normal diameter1 • Normal values (above 50 years-old)2 • Men: 1,99 cm • Women: 1,66 cm 3 Johnston (1991) J Vasc Surg, 13(3): 452-8

5. Background 1Berman (2008) J Vasc Surg, 47(2): 287-295 2 Egorova (2008) J Vasc Surg, 48(5): 1092-100 3 Katz (1997) J Vasc Surg, 25(3): 561-8 4 Lederle (1999) JAMA, 281(1): 77-82 • Abdominal aortic aneurysm affects 1% of individuals over the age of 55 and increases in incidence by 2% to 4% per decade thereafter1 • Main risk factors: • Gender: • Men are 3 times more likely to develop this type of aneurysm than women2 • Men are 10 times more likely to have an aneurysm of this type of 4 cm or larger3 • Age • Incidence rapidly increases after age 55 in men / 70 in women4

6. Background Performed in patients with high risk of post-operative complications 1 Prinssen (2004) N Engl J Med, 351(16): 1607-18 • Two major types of surgical interventions: • Open Repair (OR)1 • Endovascular Aneurysm Repair (EVAR) 2 2 Greenhalgh (2004) Lancet, 364(9437): 843-8

7. Justification • Abdominal aortic aneurysm is one of the 10 major causes of death in men over 65 years of age in western countries.1 • It is important to learn how surgical interventions used and fatality vary in different regions • knowing which regions have better outcome for either EVAR or OR will allow us to conclude where the patient has best chances of survival • Comparing Portugal’s mortality rates with those of other countries will allow us to conclude whether it is better or worse to be submitted to this type of surgical intervention in Portugal • Portugal may serve as an example of either what to do or what not to do in regard to the surgical intervention chosen for treating an abdominal aortic aneurysm 1 Katz (1997) J Vasc Surg, 25(3): 561-8

8. Aims • To analyse the baseline characteristics for patients undergoing endovascular or open abdominal aortic aneurysm repair in Portuguese mainland state hospitals during the studied period • To compare the choice of surgical approach (EVAR or OR) among the different regions; • To determine the most frequent type of abdominal aortic aneurysm (ruptured or non-ruptured) submitted to surgical intervention in Portuguese mainland state hospitals of each region; • To calculate and compare the in-hospital mortality associated: • with ruptured / non-ruptured aneurysms • with the different surgical approaches (OR and EVAR) • with the different regions

9. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

10. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

11. Study participants • All Portuguese mainland state hospitals inpatients episodes • Diagnosed with ruptured/non-ruptured abdominal aortic aneurysm • Submitted to either OR or EVAR for these conditions • Database: • records from all Portuguese mainland state hospitals • period 2000-2009* * incomplete data (from Jan-Sep)

12. Study design • Characterization of the population by: • Gender • Age • Yearly ratio ruptured/non-ruptured surgeries • Yearly ratio OR/EVAR • In-hospital mortality

13. Data collection methods • Patient hospital episode administrative database using the DRG classification system ICD-9-CM codes used for patient selection Ruptured aneurysm Non-ruptured aneurysm Open repair (OR) Endovascular repair (EVAR)

14. Variables description • Gender (raw data) • Age (raw data) • Type of Aneurysm (recoded variable) • ruptured vs. non-ruptured • Type of surgical intervention (recoded variable) • OR vs. EVAR • Mortality (raw data) • Location of mainland state hospital (recoded variable) • Division in 5 regions (Norte, Centro, Lisboa, Alentejo and Algarve) according to the NUTS II classification

15. Statistical analysis

16. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

17. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

18. Results 2474 repairs 200 excluded (date of surgery unregistered) n = 2274 28,85% Norte n = 656 15,35% Centro n = 349 54,92% Lisboa n = 1249 0,84% Alentejo n = 19 0,04% Algarve n = 1

19. Results Baseline characteristics for patients undergoing endovascular or open abdominal aortic aneurysm repair in Portuguese mainland state hospitals during the studied period There are significant differences between the age of patients * Lack of cases impaired statistical analysis. **Calculated using the Kruskal-Wallis test for age and the Chi square test for male gender. Patients submitted to EVAR in Lisboa are older than those submitted to OR in Norte, Centro and Lisboa (determined using Mann-Whitney U paired test and Holm-Bonferroni adjustment) There are no significant differences between the gender of patients

20. Yearly distribution of total Abdominal aortic aneurysm repairs according to surgical intervention

21. Yearly distribution of total Abdominal aortic aneurysm repairs according to surgical intervention OR was the preferred method from 2000-2009 EVAR is increasing since 2005

22. Results Yearly percentage of endovascular aneurysm repair in total abdominal aortic aneurysm surgical interventions in Portuguese mainland state hospitals

23. Yearly distribution of total abdominal aortic aneurysm (AAA) surgical interventions according to aneurysm type The ratio Non-ruptured/Ruptured AAA is approximately 3/1

24. Results Yearly percentage of non-ruptured aneurysm repairs in total abdominal aortic aneurysms surgical interventions in Portuguese mainland state hospitals

25. Results Regional distribution of in-hospital mortality according to type of abdominal aortic aneurysm and repair procedure No significant differences on mortality were found between OR and EVAR *Calculated using the Fisher’s exact test. **Calculated using the Chi square test. ***Lack of cases impaired statistical analysis. Tendency for EVAR to present better outcome in non-ruptured AAAs Tendency for OR to present better outcome in ruptured AAAs

26. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

27. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

28. Conclusions Gender/Age • Men were the most affected gender undergoing surgery (9 to 1) • AAAs 3 times more frequent in men • AAAs larger in men • Patients undergoing EVAR in Lisboa are significantly older than those undergoing OR in Norte, Centro and Lisboa • triage process where high-risk, older patients are selected for EVAR

29. Conclusions Open Repair vs. Endovascular Aneurysm Repair • Increase in total number of surgeries • OR as the preferred surgical intervention • Increase in the use of EVAR

30. Conclusions Open Repair vs. Endovascular Aneurysm Repair • EVAR may present better outcome in non-ruptured aneurysms (not confirmed by statistical analysis) • EVAR in ruptured aneurysm seemingly increases in-hospital mortality • only performed as last resort, on patients where survival odds are already low

31. Conclusions Ruptured aneurysm vs. non-ruptured aneurysm • Most surgical interventions performed on non ruptured aneurysm • most patients with ruptured aneurysm don’t reach hospital alive • Elective surgery presents low in-hospital mortality • Treating an aneurysm prior to its rupture is the main factor for achieving lower mortality rates

32. Prior published in-hospital and 30-day mortalities following treatment of ruptured and non-ruptured abdominal aortic aneurysms

33. Conclusions In-hospital mortality rates • Higher than those of other Western countries • Exception: Norte

34. Conclusions Limitations • Low number of patients undergoing EVAR could explain high p values obtained, impairing statistical confirmation of the EVAR better outcome, especially in Norte • The cause of death of patients with ruptured abdominal aortic aneurysm is often attributed to other pathologies – numbers may be underestimated • Surgeons’ personal testimonies refer the use of EVAR since the beginning of the decade – directly contradicts the data • Flawed insertion of the ICD-9-CM codes on database • Lack of specific training for using the software • Complex procedures to registry data

35. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

36. Table of Contents • Introduction • Background • Justification • Aims • Participants and Methods • Study participants • Study design • Data collection methods • Variable descriptions • Statistical analysis • Results • Conclusion and Discussion • References

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