class 2 advisor: alberto freitas
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Class 2
Advisor: Alberto Freitas
Introdução à Medicina II
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
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
1 Upchurch (2006) Am Fam Physician, 73(7): 1198-2042 Lederle (1997) J Vasc Surg, 26(4): 595-601
3 Johnston (1991) J Vasc Surg, 13(3): 452-8
Normal aorta Aorta with large abdominal aneurysm
Convention: an infrarenal aorta of 3 cm in diameter or larger is considered aneurysmal3
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
1 Berman (2008) J Vasc Surg, 47(2): 287-2952 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
Two major types of surgical interventions:
› Open Repair (OR)1
› Endovascular Aneurysm Repair (EVAR) 2
OR EVAR- Invasive- Higher recovery time- Normally does not require subsequent surgeries
- Less invasive- Lower recovery time- Normally requires subsequent surgeries (either immediately or for later graft replacement)
Performed in patients with high risk of post-operative complications
1 Prinssen (2004) N Engl J Med, 351(16): 1607-182 Greenhalgh (2004) Lancet, 364(9437): 843-8
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
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
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
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)
1. Characterization of the population by: Gender Age
2. Yearly ratio ruptured/non-ruptured surgeries
3. Yearly ratio OR/EVAR
4. In-hospital mortality
Patient hospital episode administrative database using the DRG classification system
Diseases and Injuries Codes441.3 Ruptured aneurysm of the abdominal aorta441.5 Aortic aneurysm unspecified site ruptured441.4 Aneurysm of the abdominal aorta, without mention of rupture441.9 Aortic aneurysm of unspecified site without mention of rupture
Procedures Codes
39.51 Clipping of aneurysm39.52 Other repair of aneurysm39.25 Aorta iliac femoral bypass38.44 Resection of vessel with replacement, abdominal aorta39.71 Endovascular implantation of graft in abdominal aorta39.79 Other endovascular repair (of aneurysm) of other vessels
ICD-9-CM codes used for patient selection
Ruptured aneurysm
Non-ruptured aneurysm
Open repair (OR)
Endovascular repair (EVAR)
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
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
2474 repairs200 excluded (date of surgery unregistered)
n = 2274
Norte
Centro
Lisboa
Alentejo
Algarve
n = 656
n = 349
n = 1249
n = 19
n = 1
28,85%15,35%54,92%
0,84%0,04%
Norte (n=656) Centro (n=349) Lisboa (n=1249) Alentejo
(n=19)
Algarve
(n=1)*p**Characteristics OR
(n=574)EVAR
(n=82)OR
(n=335)EVAR
(n=14)OR
(n=1112)EVAR
(n=137)OR
(n=19)EVAR (n=0)
OR (n=1)
EVAR (n=0)
Age, mean (SD), y
71 ± 9 73 ± 7 71 ± 9 69 ± 9 71 ± 9 74 ± 8 73 ± 10 - 65 - 0.005
Male gender, % (No.)
93.0 (534/574
)
95.1 (78/82)
92.2 (309/335
)
100 (14/14)
92.4 (1028/111
2)
86.1 (118/137
)
89.5 (17/19)
-(-/-)
100.0 (1/1)
-(-/-) 0.120
* Lack of cases impaired statistical analysis.**Calculated using the Kruskal-Wallis test for age and the Chi square test for male gender.
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
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
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
Yearly distribution of total Abdominal aortic aneurysm repairs according to surgical intervention
Yearly percentage of endovascular aneurysm repair in total abdominal aortic aneurysm surgical interventions in Portuguese mainland state hospitals
Yearly distribution of total abdominal aortic aneurysm (AAA) surgical interventions according to aneurysm type
The ratio Non-ruptured/Ruptured AAA is approximately 3/1
Yearly percentage of non-ruptured aneurysm repairs in total abdominal aortic aneurysms surgical interventions in Portuguese mainland state hospitals
AAA /Surgery types
Norte (n=656) p*
Centro (n=349) p*
Lisboa (n=1249) p**
Alentejo(n=19)*
**
Algarve (n=1)***
Total(n=2274
)p**
Non-ruptured
OR6.2%
(27/438)0.102
7.0% (16/228)
0.564
7.9% (64/815)
0.836
18.8% (3/16)
-(-/-)
7.3%(110/149
7) 0.265
EVAR 1.3% (1/76)
9.1% (1/11)
7.3% (9/123)
-(-/-)
-(-/-)
5.2%(11/210)
RupturedOR
45.6% (62/136)
0.100
54.2% (58/107)
1.000
50.8% (151/297
) 0.645
66.7% (2/3)
100% (1/1)
50.4%(274/544
) 0.163
EVAR 83.3% (5/6)
66.7% (2/3)
57.1% (8/14)
-(-/-)
-(-/-)
65.2%(15/23)*Calculated using the Fisher’s exact test.
**Calculated using the Chi square test.***Lack of cases impaired statistical analysis.
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 EVARTendency for EVAR to present better outcome in non-ruptured AAAsTendency for OR to present better outcome in ruptured AAAs
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
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
Open Repair vs. Endovascular Aneurysm Repair
Increase in total number of surgeries
OR as the preferred surgical intervention
Increase in the use of EVAR
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
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
Prior published in-hospital and 30-day mortalities following treatment of ruptured and non-ruptured abdominal aortic aneurysms
In-hospital mortality rates
Higher than those of other Western countries
Exception: Norte
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
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1. Introduction1. Background2. Justification3. Aims
2. Participants and Methods1. Study participants2. Study design3. Data collection methods4. Variable descriptions5. Statistical analysis
3. Results
4. Conclusion and Discussion
5. References
1998. Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants. Lancet, 352(9141): 1649-55.
Acosta S, Lindblad B, and Zdanowski Z, 2007. Predictors for outcome after open and endovascular repair of ruptured abdominal aortic aneurysms. Eur J Vasc Endovasc Surg, 33(3): 277-84.
Arko F R, Lee W A, Hill B B, Olcott C t, Dalman R L, Harris E J, Jr., Cipriano P, Fogarty T J, and Zarins C K, 2002. Aneurysm-related death: primary endpoint analysis for comparison of open and endovascular repair. J Vasc Surg, 36(2): 297-304.
Berman L, Dardik A, Bradley E H, Gusberg R J, and Fraenkel L, 2008. Informed consent for abdominal aortic aneurysm repair: assessing variations in surgeon opinion through a national survey. J Vasc Surg, 47(2): 287-295.
Egorova N, Giacovelli J, Greco G, Gelijns A, Kent C K, and McKinsey J F, 2008. National outcomes for the treatment of ruptured abdominal aortic aneurysm: comparison of open versus endovascular repairs. J Vasc Surg, 48(5): 1092-100, 1100 e1-2.
Garcia-Madrid C, Josa M, Riambau V, Mestres C A, Muntana J, and Mulet J, 2004. Endovascular versus open surgical repair of abdominal aortic aneurysm: a comparison of early and intermediate results in patients suitable for both techniques. Eur J Vasc Endovasc Surg, 28(4): 365-72.
Greco G, Egorova N, Anderson P L, Gelijns A, Moskowitz A, Nowygrod R, Arons R, McKinsey J, Morrissey N J, and Kent K C, 2006. Outcomes of endovascular treatment of ruptured abdominal aortic aneurysms. J Vasc Surg, 43(3): 453-459.
Greenhalgh R M, Brown L C, Kwong G P, Powell J T, and Thompson S G, 2004. Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial. Lancet, 364(9437): 843-8.
Holm S, 1979. A simple sequential rejective multiple test procedure. Scandinavian Journal of Statistics, 6: 65-70. Johnston K W, Rutherford R B, Tilson M D, Shah D M, Hollier L, and Stanley J C, 1991. Suggested standards for reporting on arterial aneurysms.
Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery. J Vasc Surg, 13(3): 452-8.
Katz D J, Stanley J C, and Zelenock G B, 1997. Gender differences in abdominal aortic aneurysm prevalence, treatment, and outcome. J Vasc
Surg, 25(3): 561-8. Lederle F A and Simel D L, 1999. The rational clinical examination. Does this patient have abdominal aortic aneurysm? JAMA, 281(1): 77-82.
Lederle F A, Freischlag J A, Kyriakides T C, Padberg F T, Jr., Matsumura J S, Kohler T R, Lin P H, Jean-Claude J M, Cikrit D F, Swanson K M, and Peduzzi P N, 2009. Outcomes following endovascular vs open repair of abdominal aortic aneurysm: a randomized trial. JAMA, 302(14): 1535-42.
Lederle F A, Johnson G R, Wilson S E, Gordon I L, Chute E P, Littooy F N, Krupski W C, Bandyk D, Barone G W, Graham L M, Hye R J, and Reinke D B, 1997. Relationship of age, gender, race, and body size to infrarenal aortic diameter. The Aneurysm Detection and Management (ADAM) Veterans Affairs Cooperative Study Investigators. J Vasc Surg, 26(4): 595-601.
Lederle F A, Wilson S E, Johnson G R, Reinke D B, Littooy F N, Acher C W, Ballard D J, Messina L M, Gordon I L, Chute E P, Krupski W C, Busuttil S J, Barone G W, Sparks S, Graham L M, Rapp J H, Makaroun M S, Moneta G L, Cambria R A, Makhoul R G, Eton D, Ansel H J, Freischlag J A, and Bandyk D, 2002. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med, 346(19): 1437-44.
Leon L R, Jr., Labropoulos N, Laredo J, Rodriguez H E, and Kalman P G, 2005. To what extent has endovascular aneurysm repair influenced abdominal aortic aneurysm management in the state of Illinois? J Vasc Surg, 41(4): 568-74.
McPhee J T, Hill J S, and Eslami M H, 2007. The impact of gender on presentation, therapy, and mortality of abdominal aortic aneurysm in the United States, 2001-2004. J Vasc Surg, 45(5): 891-9.
Monge M and Eskandari M K, 2008. Strategies for ruptured abdominal aortic aneurysms. J Vasc Interv Radiol, 19(6 Suppl): S44-50. Prinssen M, Verhoeven E L, Buth J, Cuypers P W, van Sambeek M R, Balm R, Buskens E, Grobbee D E, and Blankensteijn J D, 2004. A
randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med, 351(16): 1607-18. Rayt H S, Sutton A J, London N J, Sayers R D, and Bown M J, 2008. A systematic review and meta-analysis of endovascular repair (EVAR) for
ruptured abdominal aortic aneurysm. Eur J Vasc Endovasc Surg, 36(5): 536-44. Sadat U, Boyle J R, Walsh S R, Tang T, Varty K, and Hayes P D, 2008. Endovascular vs open repair of acute abdominal aortic aneurysms--a
systematic review and meta-analysis. J Vasc Surg, 48(1): 227-36. Schermerhorn M L, O'Malley A J, Jhaveri A, Cotterill P, Pomposelli F, and Landon B E, 2008. Endovascular vs. open repair of abdominal aortic
aneurysms in the Medicare population. N Engl J Med, 358(5): 464-74.
Sharif M A, Lee B, Makar R R, Loan W, and Soong C V, 2007. Role of the Hardman index in predicting mortality for open and endovascular repair of ruptured abdominal aortic aneurysm. J Endovasc Ther, 14(4): 528-35.
Starnes B W, Quiroga E, Hutter C, Tran N T, Hatsukami T, Meissner M, Tang G, and Kohler T, 2010. Management of ruptured abdominal aortic aneurysm in the endovascular era. J Vasc Surg, 51(1): 9-17; discussion 17-8.
Sullivan C A, Rohrer M J, and Cutler B S, 1990. Clinical management of the symptomatic but unruptured abdominal aortic aneurysm. J Vasc Surg, 11(6): 799-803.
Upchurch G R, Jr. and Schaub T A, 2006. Abdominal aortic aneurysm. Am Fam Physician, 73(7): 1198-204. Visser J J, Williams M, Kievit J, and Bosch J L, 2009. Prediction of 30-day mortality after endovascular repair or open
surgery in patients with ruptured abdominal aortic aneurysms. J Vasc Surg, 49(5): 1093-9. Vogel T R, Dombrovskiy V Y, Haser P B, and Graham A M, 2009. Has the implementation of EVAR for ruptured AAA
improved outcomes? Vasc Endovascular Surg, 43(3): 252-7. Wakefield T W, Whitehouse W M, Jr., Wu S C, Zelenock G B, Cronenwett J L, Erlandson E E, Kraft R O, Lindenauer S
M, and Stanley J C, 1982. Abdominal aortic aneurysm rupture: statistical analysis of factors affecting outcome of surgical treatment. Surgery, 91(5): 586-96.
Wanhainen A, Bylund N, and Bjorck M, 2008. Outcome after abdominal aortic aneurysm repair in Sweden 1994-2005. Br J Surg, 95(5): 564-70.
Wahlgren C M and Malmstedt J, 2008. Outcomes of endovascular abdominal aortic aneurysm repair compared with open surgical repair in high-risk patients: results from the Swedish Vascular Registry. J Vasc Surg, 48(6): 1382-8; discussion 1388-9.
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