IMPACT OF RISK FACTORS ON MORTALITY AFTER ELECTIVE OPEN REPAIR OF
ABDOMINAL AORTIC ANEURYSMS
Ana Luísa Pinto (analuisapinto28@hotmail.com), Catarina Machado (menina.catarina@gmail.com),
Filipa Gomes (filipa56popcorn@hotmail.com), Hugo Sousa (hmlsbiff@hotmail.com), José Henrique
Messias (jham14@hotmail.com), Joana Teixeira (joanamnt@hotmail.com), Luís Miguel Lázaro
(miguel_lazaro@portugalmail.com),
Miguel
Quinta
e
Costa
(rafaela_parreira@hotmail.com),
Maria
Filipa
Figueiredo
(m.filipa.figueiredo@hotmail.com),
(miguelmascarenhascdf@hotmail.com),
Sérgio
Cardoso
(s3rgio13@gmail.com),
Rafaela
Sílvia
Parreira
Farraposo
(silvia@estg.ipleiria.pt), Sofia Figueiredo (sofia_b_figueiredo@hotmail.com).
MD PhD Sérgio Sampaio, Class 5
ABSTRACT
BACKGROUND: There are several risk factors for the development of Abdominal Aortic Aneurysms
(AAA). Despite recent advances in medical care, Elective Open Repair (EOR) remains the “gold
standard” procedure for AAA repair and even in selected patients the overall mortality rate is roughly
5%. AIMS OF THE STUDY: This study aims to summarize risk factors, postoperative complications
and mortality rates of patients with AAA undergoing EOR, and analyze the influence of risk factors on
patients’ outcome, thus contributing to the improvement of outcome prediction after EOR.
METHODS: Two-hundred and three papers were identified regarding AAA, elective open
repair/surgery and mortality in the PubMed/Medline database. From those, 50 provided data related
to risk factors exposition, postoperative complications and clinical outcome. RESULTS: Males with
advanced age (median 71.0years old) and with a median aneurysm diameter of 5.9 cm were the
most frequent patients with AAA among all studies. The most common risk factors found were
Hypertension (median 60.0%), Smoking Habits (median 54.2%), History of Cardiac Diseases
(median 44.3%), and History of Pulmonary Diseases (median 23.0%). Median occurrence of
morbidity events was 31.0%, while mortality rate was 4.0%. Meta-analysis revealed that
Hypertension (OR=2.95; p<0.001), Chronic Renal Failure (OR=2.78; p<0.001), History of Cardiac
Disease (OR=1.93; p<0.001), Female Gender (OR=1.58; p<0.001), Aneurysm Diameter (OR=1.58;
p<0.011) and Age (OR=1.07; p<0.001) were associated with increased risk of death after EOR, while
History of Pulmonary Disease (OR=1.32; p=0.112) and Diabetes Mellitus (OR=1.28; p=0.309) did not
provide strong data. Moreover, Smoking habits revealed not to influence the patients’ outcome after
1
EOR. CONCLUSION: This study provides important data that contribute to selection of patients that
are at high risk of death after EOR, and therefore prediction of patient outcome may be improved.
KEY-WORDS: Abdominal Aortic Aneurysm (AAA); elective open repair (EOR); risk factors;
postoperative complications; mortality; morbidity; meta-analysis review.
INTRODUCTION
An Abdominal Aortic Aneurysm (AAA) is considered to be an abnormal widening of 1.5-folds the
normal diameter of the aorta below the renal arteries, and its development is related to several risk
factors which are associated with the weakening of the aortic wall, namely: smoking, diabetes,
elevated cholesterol, family history, hypertension and atherosclerosis (1-3).
Thus, AAA is a severe health condition that can lead to death if rupture occurs. Despite the different
options to prevent rupture, this condition is responsible for approximately 9,000 deaths per year (1).
In the United States, 40,000 patients are submitted to elective surgical repair of an AAA each year,
preoperative mortality occurring in 2-8% of properly selected patients (4-6).
The incidence of AAA increases with age, rarely developing before the age of 50, and is much more
common in men (1;6). When an aneurysm is detected, clinicians may have to decide which treatment
options must be used, based on patients’ life expectancy and aneurysms’ size: active surveillance,
immediate/emergency repair, elective open repair (EOR) and endovascular repair (EVAR) (6;7). As
an aneurysm grows progressively, rupture can occur at any moment, and even with an emergency
repair the mortality remains to be roughly 50%.
EOR has been the most used approach to repair AAA, and is undertaken only when the risk of
rupture is considered to be high (8). EOR may face several peri and postoperative complications,
such as: venous bleeding, resulting from iliac or left renal veins injury; gastrointestinal ischemia, more
likely to occur following ruptured AAA repair; cardiac complications, which constitute the most serious
threat to patients after AAA repair; pulmonary complications; and also renal failure. AAA repair is,
therefore a technically difficult procedure and despite late complications being infrequent, mortality
after EOR still ranges 3 – 10% (4;9).
Several studies have suggested that success rates of EOR depend on patient’s condition and
exposure to different risk factors (10-12). Therefore, as it is unclear what risk factors influence the
mortality after EOR, we performed a systematic review followed by meta-analysis to summarize risk
factors, postoperative complications and mortality rates, and to analyse the influence of risk factors
on patient’s outcome after EOR.
PARTICIPANTS AND METHODS
2
Study participants and Sampling Methods
A total of 203 papers were identified by searching the PUBMED/Medline database, on October 2007,
with the following query: (("abdominal aortic aneurysm"[Text Word] OR "aortic aneurysm,
abdominal"[MeSH Terms] OR aaa[Text Word]) AND elective[All Fields] AND open[All Fields]) AND
((("wound healing"[TIAB] NOT Medline[SB]) OR "wound healing"[MeSH Terms] OR repair[Text
Word]) OR ("surgery"[Subheading] OR "operative surgical procedures"[Text Word] OR "surgical
procedures, operative"[MeSH Terms] OR "surgery"[MeSH Terms] OR surgery[Text Word])) AND
mortality[Text Word].
Study design
Papers had to fulfil the following criteria to be included in this study: 1) patients must have been
diagnosed with abdominal aortic aneurysms (AAA); 2) patients must have been submitted to elective
open repair/surgery; 3) papers should provide data about risk factors and clinical outcome after
elective open repair of AAA. Studies were excluded if: 1) patients had thoraco-abdominal or
abdomino-iliac aneurysms; 2) patients had been submitted to emergency repair after ruptured AAA;
3) patients had been submitted to EVAR; 4) studies were Reviews, Systematic Reviews, Metaanalysis, Letters or Editorials; 5) published in other language than English, French, Spanish or
Portuguese and 6) there were no data related to the study design.
Eihty papers were selected and requested either online, by library acquisition or by e-mail request to
authors. Only 67 articles were possible to obtain and then submitted to a second triage in order to
select the articles that considered the variables of interest for the study. This second triage step
revealed that 46 papers, which represent 50 individual studies, had information about the variables of
interest for the statistical analysis (preoperative clinical variables, risk factors, postoperative
complications, and patients’ outcome). These 50 studies were considered for the estimation of the
frequency of all variables of interest in the study; nevertheless, 17 papers were used to summarize
patients’ risk factors impact on clinical outcome.
Variables description and data acquisition method
A review was performed in order to extract data from selected papers: 1) general characteristics,
such as: name of first author, year of publication, country of origin, type of study, sample size; 2)
clinical variables, such as: age, gender and aneurysm diameter; 3) risk factors exposition: diabetes
mellitus, history of cardiac disease (previous myocardial infarction or coronary disease),
hypertension, history of pulmonary disease (pulmonary embolism or Chronic Obstructive Pulmonary
Disease, COPD), chronic renal failure (according to creatinine levels), and smoking habits; 4)
postoperative complications, such as: general morbidity events, gastrointestinal ischemia, multiorgan
3
failure, renal failure, general cardiac complications, myocardial infarction, and respiratory
complications; and 5) clinical outcome of the patients. The clinical outcome of interest for this study
was defined as mortality measured 30 days after surgery. In cases with different outcomes per report,
each outcome was analyzed as an independent study.
Statistical analysis
All collected data was inserted on a database using Statistical Package for Social Sciences (SPSS)
Version 16.0 for Windows (SPSS Inc). SPSS software was used to summarize the median
proportion, range of values and standard deviations of all clinical variables, risk factors exposition and
postoperative complications, as well as to summarize the mortality rates of all studies. The Epi Info™
Version 6 was used to perform a Χ2 analysis in order to determine the Odds Ratio (OR) and its 95%
confidence interval, when such information was not available in the paper. Meta-analysis of data was
performed with the open access program R Version 2.6.2 to elaborate the Forest Plot graphics in
order to combine the influence of risk factors on patients’ outcome.
RESULTS
Summary of clinical variables, risk factors and postoperative complications
The first approach to this study was performed by summarizing data about clinical variables, risk
factors and postoperative complications, as well as to summarize the mortality rate within all studies
(Table I).
The systematic review revealed an increased frequency of Male Gender (median 86.9%) among
studies. In addition, the median of mean age of diagnosis was 71.4 years, and the median mean
aneurysm diameter was 5.9 cm. Most common risk factors were hypertension (median 60.0%),
smoking (median 54.2%), history of cardiac disease (median 44.3%), history of pulmonary disease
(median 23.0%), and diabetes mellitus and chronic renal failure (both with median 9.5%).
Morbidity rates varied a lot among studies, and statistical analysis revealed a median occurrence of
31.0%, with the most frequent postoperative complications being: Respiratory Complications (median
7.5%), Cardiac Complications (median 5.7%), and Multi Organ Failure (median 3.6%). The median
mortality rate was 4.0%.
Meta-analysis
The meta-analysis data of risk factors impact on patients’ mortality after EOR are available in Figure
1 (8;13-28). Hypertension (HT), Chronic Renal failure (CRF), History of Cardiac Disease (HCD),
Female Gender and Age revealed to be associated with increased risk of death after EOR in a
statistically significant way, while History of Pulmonary Disease (HPD) and Diabetes Mellitus (DM)
4
provided mere trends, not statistically significant. Moreover, Smoking habits revealed no influence on
the risk of death after EOR.
Data show that Hypertension and Chronic Renal Failure represent an almost 3-folds increased risk of
death after EOR; Cardiac Disease History represent an increased risk of almost 2-folds; Female
Gender and an increment of 1cm in the Aneurysm Diameter revealed a 58% increased risk; and Age
has also proved to influence the risk of death after EOR, with an increment of 7% per year.
DISCUSSION
Limitations of the study
Although, the literature search was extremmely comprehensive (see study design section), which
should have minimized reporting biases, it still have some limitations. We found it hard to reach the
most sensitive query, mainly due to the absence of a unique term to define “elective open repair”.
Furthermore, we were forced to apply the query without any reference to any risk factor or
postoperative complication since there is a wide variety and many of them are expressed differently,
and therefore, the application of inclusion/exclusion criteria might have not been as accurate as we
aimed. We also observed that studies were extremely heterogeneous and the majority of them failed
to state some of the demographic and preoperative clinical variables, as well as risk factors
exposition, potentially of interest to perform a more accurate systematic review. Moreover, only a few
studies have stated the impact of each risk factor on mortality which was extremely important to the
meta-analysis study. Finally, we observed that the underlying prevalence of AAA may be the reason
for between-study heterogeneity (2).
Epidemiological Data
This study combined the information concerning the frequency of the different risk factors for AAA
development, revealing male gender, advanced age, hypertension, smoking and cardiac disease as
the major risk factors found among all studies – Table I. Moreover, the most frequent postoperative
complications found were respiratory and cardiac complications, and the mortality rate of patients
with AAA attending EOR was 4.0%.
Many studies reffer that men are more frequently and earlier affected by AAA development than
women, with a male:female ratio of 9:1 (29). Our results have shown that AAA was significantly more
frequent in male gender (median 86.9%) and in patients with advanced age (median of means of
71.4 years old), a similar distribution to those shown in literature which refer that AAA are more
common in men with age ranging 65-75 y.o. (1, 26, 29, 30).
Despite urgent treatments that aortic aneurysms require, the guidelines refer that for those smaller
than 4.5 cm, only ultrasonographic surveillance every 6 months is recommended. When aneureysms
5
reach a size between 4.5 and 5 cm, the follow-up time showld be narrowed to every 3 months,
nevertheless, in young patiens <65 y.o. with an AAA of 4 to 5 cm, elective surgery instead of
conservative surveillance should considered. AAAs’ with a diameter of 5.5 cm or over, are indicated
for EOR or EVAR (29). In this study, the data related to the average aneurysm size revealed that
patients had a mean aneurysm diameter of 5.9 cm, which taking in consideration the advanced age
of patients in agreement with the guidelines for AAA treatment.
The results show that male gender, hypertension, current cigarrette smoking and history of cardiac
disease were the major risk factors found among all papers – Table I. The majority of review studies
refer age, smoking, and gender as the most significant AAA risk factors, although, hypertension and
history of cardiac disease should be also considered important (2;12;30).
Literature suggests a wide variety of postoperative complications, and most of them are correlated
with the healthy condition of the patient prior to the surgery, or also to the experience of the surgical
team. It is commonly accepted that at least between 5-25% of patients suffer one postoperative
complication prior to 30 days after surgery (5;12). Our study showed that the median occurrence of
Morbidity events was of 31.0%, although, this variable varied a lot among all studies. Therefore, we
may assume that these differences might be correlated with the health condition of patients. Our data
reveal that the most frequent postoperative complications found were Respiratory, Cardiac
complications, and Multi Organ Failure – Table I. The main conclusion to take form these data, and
according to some studies, is that patients might need to stay at an Intensive Care Unit (ICU) for a
few time in order to reestablish the optimal conditions for the patient to go home and complete the
recover without any more complication (10).
Another curious finding was that mortality rates also varied a lot among studies, ranging between 017% and with a mean mortality rate of 4.0% – Table I. Mortality rates prior to 30 days after surgery for
patients undergoing EOR ranges between 1-5%, although in some surgical teams this can be 0%.
Thus, our data reveals a similar trend to those found in the majority of the published studies (1, 3, 79, 30). Nevertheless, and despite the different condition of patients, in-hospital care conditions are
extremely important to prevent higher mortality rates (10).
Influence of risk factor on patient’s outcome after EOR
Despite the peri and postoperative complications, EOR remains the gold-standard procedure for AAA
repair worldwide, since it is considered as definitive, requiring only imagiologic surveillance (31). Up
to our knowledge this is the first meta-analysis that combines the information related to the impact of
risk factors on mortality after AAA EOR. Although there were only 17 studies providing the necessary
data for the meta-analysis, it was possible to achieve interesting results considering the role of risk
factors on patients’ outcome after EOR (Figure 1). The results show that hypertension, chronic renal
6
failure, history of cardiac disease, female gender and age are correlated to increasd risk of death
after EOR, and that history of pulmonary disease and diabetes mellitus require more studies to reach
better conclusions. Current smoking habits revealed not to influence the risk of death after EOR.
Cigarette smoking has been consistently associated with increased risk of AAA development,
moreover, several studies suggested that the risk is different according to smoking condition (ever,
current, or continued smoker) (3). Therefore, we were surprised that statistical analysis revealed no
impact of smoking on mortality (OR=1.00; p=0.987). Curiously, some authors refer that patients may
benefit of smoking cessation after being diagnosed with AAA (3).
The analysis of the impact of epidemiological data on patients’ outcome revealed that Female gender
increases the risk of death after EOR in 58% when compared to Male gender, which represent a
significant risk factor for AAA. However, it is well known that when females develop AAA, usually it
has more severe consequences and death can occur shortly after surgery. A similar effect was shown
when we observed that an increment of 1cm of the Aneurysm Diameter represents a 58% increase
risk of death after EOR. We have also observed that despite not statistically significant, Age
influences the risk of death after EOR, with an increment of 7% per year. Several authors defend that
mortality rate of patients with AAA may also increease with age, which might be biased by the
diminuition of patients’ healthy condition (32).
Results have also shown that when considering the impact of PDH and DM on patients’ outcome,
although, the analysis point to an increase of 32% and 28%, respectively, in the risk of death after
EOR, the data were not statistically significant. Interestingly, it has been suggested that DM is not
consistently considered a risk factor for AAA (3) , therefore it stills required more studies to clarify its
role wither on AAA development or its impact on patients’ outcome.
According to our data, HT and CRF were responsible for an almost 3-fold increased risk for death
after EOR (OR=2.95, p<0.001; OR=2.78, p<0.001, respectively). These risk factors are well
correlated with patients’ health condition and are extremely important for the recovery after any
surgical (12), thus, it was not a surprise to observe that they might increase the risk of death. CRF
has been assumed as a significant risk factor, but the way authors considered it to be present or
absent are not actually uniform. Despite the majority of authors used the creatinine levels to assume
the CRF, the “cut-off” value was not the equal, and while some used 1.5mg/dL others have chosen
2.0mg/dL. This data might be extremely useful in the future, but authors need to provide more
uniform values in order to establish a clear role.
Finally, as expected, Cardiac Disease History (CDH) has proven to be an increased risk factor for
death after EOR (OR=1.93 with p<0.001). Death after any invasive surgical procedure in patients who
had previous CDH is more frequent, since it is common that people who suffered cardiac events may
have repetitions shortly in time and mainly after surgeries.
7
Conclusions
EOR, though challenged by Endovascular Repair during the last decades, has managed to hold its
ground thanks to good results, proven to be obtainable in many centers.
This study provides important findings that may contribute to the development of a decision tree to
help clinicians to predict, by simple analysis of risk factor exposition, patient’s outcome before
submitting then to EOR and therefore select patients that can expect a good outcome after EOR.
REFERENCE LIST
(1) Gillum RF. Epidemiology of aortic aneurysm in the United States. J Clin Epidemiol 1995;
48(11):1289-1298.
(2) Cornuz J, Sidoti PC, Tevaearai H, Egger M. Risk factors for asymptomatic abdominal aortic
aneurysm: systematic review and meta-analysis of population-based screening studies. Eur J
Public Health 2004; 14(4):343-349.
(3) Golledge J, Muller J, Daugherty A, Norman P. Abdominal aortic aneurysm: pathogenesis and
implications for management. Arterioscler Thromb Vasc Biol 2006; 26(12):2605-2613.
(4) Krupski WC, Rutherford RB. Update on open repair of abdominal aortic aneurysms: the
challenges for endovascular repair. J Am Coll Surg 2004; 199(6):946-960.
(5) Wilt TJ, Lederle FA, Macdonald R, Jonk YC, Rector TS, Kane RL. Comparison of
endovascular and open surgical repairs for abdominal aortic aneurysm. Evid Rep Technol
Assess (Full Rep ) 2006;(144):1-113.
(6) Lucas FL, Stukel TA, Morris AM, Siewers AE, Birkmeyer JD. Race and surgical mortality in the
United States. Ann Surg 2006; 243(2):281-286.
(7) Calligaro KD, Dougherty MJ, Hollier LH. Diagnosis and treatment of aortic and peripheral
arterial aneurysms. Philadelphia: Saunders; 1999.
(8) Lederle FA, Wilson SE, Johnson GR, Reinke DB, Littooy FN, Acher CW et al. Immediate
repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002;
346(19):1437-1444.
(9) Hadjianastassiou VG, Franco L, Jerez JM, Evangelou IE, Goldhill DR, Tekkis PP et al.
Informed prognosis [corrected] after abdominal aortic aneurysm repair using predictive
modeling techniques [corrected]. J Vasc Surg 2006; 43(3):467-473.
(10) El SK, Halawa M, Kotze C, Francis I, Doyle T, Yusuf W. Complications of open abdominal
aortic surgery: the endovascular solution. Interact Cardiovasc Thorac Surg 2008; 7(1):121124.
(11) Chaikof EL, Fillinger MF, Matsumura JS, Rutherford RB, White GH, Blankensteijn JD et al.
Identifying and grading factors that modify the outcome of endovascular aortic aneurysm
repair. J Vasc Surg 2002; 35(5):1061-1066.
8
(12) Hirsch AT, Haskal ZJ, Hertzer NR, Bakal CW, Creager MA, Halperin JL et al. ACC/AHA
Guidelines for the Management of Patients with Peripheral Arterial Disease (lower extremity,
renal, mesenteric, and abdominal aortic): a collaborative report from the American
Associations for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular
Angiography and Interventions, Society for Vascular Medicine and Biology, Society of
Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (writing
committee to develop guidelines for the management of patients with peripheral arterial
disease)--summary of recommendations. J Vasc Interv Radiol 2006; 17(9):1383-1397.
(13) Bonardelli S, Parrinello G, De LM, Nodari F, Maffeis R, Cervi E et al. Risk factors for
immediate results and long-term survival following elective open surgery for AAA. Statistical
analysis of 1111 consecutively-treated patients. Ann Ital Chir 2007; 78(4):265-276.
(14) Conrad MF, Crawford RS, Pedraza JD, Brewster DC, Lamuraglia GM, Corey M et al. Longterm durability of open abdominal aortic aneurysm repair. J Vasc Surg 2007; 46(4):669-675.
(15) Hirzalla O, Emous M, Ubbink DT, Legemate D. External validation of the Glasgow Aneurysm
Score to predict outcome in elective open abdominal aortic aneurysm repair. J Vasc Surg
2006; 44(4):712-716.
(16) Rigberg DA, Zingmond DS, McGory ML, Maggard MA, Agustin M, Lawrence PF et al. Age
stratified, perioperative, and one-year mortality after abdominal aortic aneurysm repair: a
statewide experience. J Vasc Surg 2006; 43(2):224-229.
(17) Hertzer NR, Mascha EJ. A personal experience with factors influencing survival after elective
open repair of infrarenal aortic aneurysms. J Vasc Surg 2005; 42(5):898-905.
(18) Leon LR, Jr., Labropoulos N, Laredo J, Rodriguez HE, Kalman PG. To what extent has
endovascular aneurysm repair influenced abdominal aortic aneurysm management in the state
of Illinois? J Vasc Surg 2005; 41(4):568-574.
(19) Hua HT, Cambria RP, Chuang SK, Stoner MC, Kwolek CJ, Rowell KS et al. Early outcomes of
endovascular versus open abdominal aortic aneurysm repair in the National Surgical Quality
Improvement Program-Private Sector (NSQIP-PS). J Vasc Surg 2005; 41(3):382-389.
(20) Nesi F, Leo E, Biancari F, Bartolucci R, Rainio P, Satta J et al. Preoperative risk stratification
in patients undergoing elective infrarenal aortic aneurysm surgery: evaluation of five risk
scoring methods. Eur J Vasc Endovasc Surg 2004; 28(1):52-58.
(21) Zeebregts CJ, Geelkerken RH, van der PJ, Huisman AB, de SP, van Det RJ. Outcome of
abdominal aortic aneurysm repair in the era of endovascular treatment. Br J Surg 2004;
91(5):563-568.
(22) Liapis CD, Kakisis JD, Dimitroulis DA, Daskalopoulos M, Nikolaou A, Kostakis AG. Carotid
ultrasound findings as a predictor of long-term survival after abdominal aortic aneurysm repair:
a 14-year prospective study. J Vasc Surg 2003; 38(6):1220-1225.
(23) Biancari F, Heikkinen M, Lepantalo M, Salenius JP. Glasgow Aneurysm Score in patients
undergoing elective open repair of abdominal aortic aneurysm: a Finnvasc study. Eur J Vasc
Endovasc Surg 2003; 26(6):612-617.
(24) Biancari F, Leo E, Ylonen K, Vaarala MH, Rainio P, Juvonen T. Value of the Glasgow
Aneurysm Score in predicting the immediate and long-term outcome after elective open repair
of infrarenal abdominal aortic aneurysm. Br J Surg 2003; 90(7):838-844.
9
(25) Rayan SS, Hamdan AD, Campbell DR, Akbari CM, Hook SC, Skillman J et al. Is diabetes a
risk factor for patients undergoing open abdominal aortic aneurysm repair? Vasc Endovascular
Surg 2002; 36(1):33-40.
(26) Kruger A, Foster W, Love A, Woodruff P, Blackford J. Abdominal aortic aneurysm repair in the
veteran population. ANZ J Surg 2002; 72(9):628-631.
(27) Hertzer NR, Mascha EJ, Karafa MT, O'Hara PJ, Krajewski LP, Beven EG. Open infrarenal
abdominal aortic aneurysm repair: the Cleveland Clinic experience from 1989 to 1998. J Vasc
Surg 2002; 35(6):1145-1154.
(28) Brady AR, Fowkes FG, Greenhalgh RM, Powell JT, Ruckley CV, Thompson SG. Risk factors
for postoperative death following elective surgical repair of abdominal aortic aneurysm: results
from the UK Small Aneurysm Trial. On behalf of the UK Small Aneurysm Trial participants. Br
J Surg 2000; 87(6):742-749.
(29) Zankl AR, Schumacher H, Krumsdorf U, Katus HA, Jahn L, Tiefenbacher CP. Pathology,
natural history and treatment of abdominal aortic aneurysms. Clin Res Cardiol 2007;
96(3):140-151.
(30) Lederle FA, Johnson GR, Wilson SE, Chute EP, Hye RJ, Makaroun MS et al. The aneurysm
detection and management study screening program: validation cohort and final results.
Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators. Arch
Intern Med 2000; 160(10):1425-1430.
(31) Upchurch GR, Jr., Schaub TA. Abdominal aortic aneurysm. Am Fam Physician 2006;
73(7):1198-1204.
(32) Wilmink AB, Quick CR. Epidemiology and potential for prevention of abdominal aortic
aneurysm. Br J Surg 1998; 85(2):155-162.
10
Table I - Risk factors, postoperative complications, morbidity and mortality rates
Number of
Studies
Minimum
Percentil 25
Median
Percentil 75
Maximum
Mean Age (y.o.)
45
65,8
69,5
71,0
72,2
83,0
Mean Aneurysm Diameter (cm)
29
4,7
5,6
5,9
6,3
6,5
Males in Patients Group (%)
46
67,0
78,0
86,9
90,3
99,2
Patients with HT (%)
36
30,0
46,1
60,0
72,5
88,6
Patients with Smoking (%)
30
4,0
32,8
54,2
75,8
97,1
Patients with CDH (%)
38
2,4
27,2
44,3
50,4
76,0
Patients with PDH (%)
33
6,7
14,0
23,0
37,0
58,8
Patients with CRF (%)
30
1,5
6,0
9,5
17,2
26,0
Patients with DM (%)
37
2,9
7,0
9,5
12,0
36,0
Total Morbidity events (%)
17
0,3
14,8
31,9
47,6
68,1
RespC events (%)
23
0,5
5,0
7,5
13,9
40,0
CardiacC events (%)
25
1,0
2,6
5,7
9,8
25,7
MOFailure events (%)
8
0,8
1,2
3,6
6,8
8,0
MI events (%)
17
0,6
1,2
2,2
6,4
10,9
GIsch events (%)
14
0,2
0,9
1,7
3,8
28,6
RFailure events (%)
18
0,2
1,0
1,5
6,2
17,1
<30 day Mortality (%)
50
0,0
2,7
4,4
5,5
17,1
11
Figure 1 – Forest plots.
Mean Age
Hypertension
Mean Aneurysm Diameter
Diabetes Mellitus
Female Gender
History of Pulmonary Disease
History of Cardiac Disease
Chronic RenalFailure
Smoking
12