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1.
One hundred and six patients with abdominal aortic aneurysms (AAAs) of 2.5 to 3.9 cm in anteroposterior diameter were reexamined by ultrasound every 6 months for up to 3 years after diagnosis. Annual growth rates were 0.11 cm +/- 0.03 (mean +/- SE) for AAAs 2.5 to 2.9 cm and 0.29 cm +/- 0.08 for AAAs 3.5 to 3.9 cm (P = 0.002). In 73 patients (69%) the annual rate of increase in diameter was 0.2 cm or less and only 12 aneurysms (11%) grew at more than 0.5 cm per annum. We conclude that: (1) for AAAs less than 4.0 cm diameter remeasurement more often than every 6 months is unnecessary; (2) interval screening (rescreening) for AAAs more frequently than 5 yearly is unlikely to detect sufficient clinically significant aneurysms to be worthwhile.  相似文献   

2.
PURPOSE: This study compared the volume and morphology of intraluminal thrombus (ILT) in intact and ruptured abdominal aortic aneurysms (AAAs). METHODS: ILT volume in 67 intact AAAs and in 31 ruptured AAAs was assessed by using computed tomography (CT) angiography to measure the major and minor diameter of the outer wall and lumen of AAA as outlined by contrast at multiple sites. ILT thrombus morphology was recorded by AutoCAD 2000 software. Four equidistant images traced from the CT scan were recorded along the length of AAA. Thrombus volume was categorized as anterior-eccentric if the calculated area of thrombus was greater anteriorly, posterior-eccentric if greater posteriorly, eccentric-equal if the difference between the anterior and posterior thrombus was 相似文献   

3.
OBJECTIVE: The purpose of this study was to calculate abdominal aortic aneurysm (AAA) wall stresses in vivo for ruptured, symptomatic, and electively repaired AAAs with three-dimensional computer modeling techniques, computed tomographic scan data, and blood pressure and to compare wall stress with current clinical indices related to rupture risk. METHODS: CT scans were analyzed for 48 patients with AAAs: 18 AAAs that ruptured (n = 10) or were urgently repaired for symptoms (n = 8) and 30 AAAs large enough to merit elective repair within 12 weeks of the CT scan. Three-dimensional computer models of AAAs were reconstructed from CT scan data. The stress distribution on the AAA as a result of geometry and blood pressure was computationally determined with finite element analysis with a hyperelastic nonlinear model that depicted the mechanical behavior of the AAA wall. RESULTS: Peak wall stress (maximal stress on the AAA surface) was significantly different between groups (ruptured, 47.7 +/- 6 N/cm(2); emergent symptomatic, 47.5 +/- 4 N/cm(2); elective repair, 36.9 +/- 2 N/cm(2); P =.03), with no significant difference in blood pressure (P =.2) or AAA diameter (P =.1). Because of trends toward differences in diameter, comparison was made only with diameter-matched subjects. Even with identical mean diameters, ruptured/symptomatic AAAs had a significantly higher peak wall stress (46.8 +/- 4.5 N/cm(2) versus 38.1 +/- 1.3 N/cm(2); P =.05). Maximal wall stress predicted risk of rupture better than the LaPlace equation (20.7 +/- 5.7 N/cm(2) versus 18.8 +/- 2.9 N/cm(2); P =.2) or other proposed indices of rupture risk. The smallest ruptured AAA was 4.8 cm, but this aneurysm had a stress equivalent to the average electively repaired 6.3-cm AAA. CONCLUSION: Peak wall stresses calculated in vivo for AAAs near the time of rupture were significantly higher than peak stresses for electively repaired AAAs, even when matched for maximal diameter. Calculation of wall stress with computer modeling of three-dimensional AAA geometry appears to assess rupture risk more accurately than AAA diameter or other previously proposed clinical indices. Stress analysis is practical and feasible and may become an important clinical tool for evaluation of AAA rupture risk.  相似文献   

4.
OBJECTIVE: to compare predicted and actual mortality rates, using POSSUM scoring, after elective repair of abdominal aortic aneurysms (AAAs) detected from the Gloucestershire Aneurysm Screening Programme and those discovered incidentally. METHODS: a sample of 276 men undergoing elective AAA repair in Gloucestershire between 1991 and 1998 was studied. AAAs were either detected from the screening programme or were discovered incidentally and referred from other sources. Mortality data relating to these patients have been recorded prospectively. POSSUM scoring was performed retrospectively from patients> notes in both groups and related to outcome (30 day and in-hospital mortality). POSSUM and P-POSSUM methodology were used to compare observed and predicted mortality rates. RESULTS: in the 276 men who had elective AAA repair, the overall mortality rate was 7%. Mortality was lower in screen-detected AAAs (3/111, 3%) than AAAs discovered incidentally (16/175, 9%) (p=0.05). Preoperative physiology scores were significantly lower in men with a screen-detected AAA (median 19, range 13-29 versus 21, 12-41, p<0.001). POSSUM operative scores were similar between the groups. Actual versus predicted death ratios in the sample group were more accurate using POSSUM (ratio 0.93) than P-POSSUM (2.38) analysis. CONCLUSIONS: men with a screen-detected AAA had a lower mortality rate after elective repair than in those detected incidentally; lower preoperative physiology scores suggested they were fitter (as well as younger). In this study POSSUM analysis more accurately predicted outcome than P-POSSUM.  相似文献   

5.
Purpose: The goal of the current study was to identify the risk of rupture in the entire abdominal aortic aneurysm (AAA) population detected through screening and to review strategies for surgical intervention in light of this information. Methods: Two hundred eighteen AAAs were detected through ultrasound screening of a family practice population of 5394 men and women aged 65 to 80 years. Subjects with an AAA of less than 6.0 cm in diameter were followed prospectively with the use of ultrasound, according to our protocol, for 7 years. Patients were offered surgery if symptomatic, if the aneurysm expanded more than 1.0 cm per year, or if aortic diameter reached 6.0 cm. Results: The maximum potential rupture rate (actual rupture rate plus elective surgery rate) for small AAAs (3.0 to 4.4 cm) was 2.1% per year, which is less than most reported operative mortality rates. The equivalent rate for aneurysms of 4.5 to 5.9 cm was 10.2% per year. The actual rupture rate for aneurysms up to 5.9 cm using our criteria for surgery was 0.8% per year Conclusion: In centers with an operative mortality rate of greater than 2%, (1) surgical intervention is not indicated for asymptomatic AAAs of less than 4.5 cm in diameter, and (2) elective surgery should be considered only for patients with aneurysms between 4.5 and 6 cm in diameter that are expanding by more than 1 cm per year or for patients in whom symptoms develop. In centers with elective mortality rates of greater than 10% for abdominal aortic aneurysm (AAA) repair, the benefit to the patient of any surgical intervention for an asymptomatic AAA of less than 6.0 cm in diameter is questionable. (J Vasc Surg 1998;28:124-8.)  相似文献   

6.
Zarins CK  Crabtree T  Bloch DA  Arko FR  Ouriel K  White RA 《Journal of vascular surgery》2006,44(5):920-29; discussion 929-31
OBJECTIVE: The appropriate size threshold for endovascular repair of small abdominal aortic aneurysms (AAA) is unclear. We studied the outcome of endovascular aneurysm repair (EVAR) as a function of preoperative aneurysm diameter to determine the relationship between aneurysm size and long-term outcome of endovascular repair. METHODS: We reviewed the results of 923 patients treated in a prospective, multicenter clinical trial of EVAR. Small aneurysms were defined according to two size thresholds of 5.5 cm and 5.0 cm. Two-way analysis was used to compare patients with small aneurysms (<5.5 cm, n = 441) to patients with large aneurysms (> or =5.5 cm, n = 482). An ordered three-way analysis was used to compare patients with small AAA (<5.0 cm, n = 145), medium AAA (5.0 to 5.9 cm, n = 461), and large AAA (> or =6.0 cm, n = 317). The primary outcome measures of rupture, AAA-related death, surgical conversion, secondary intervention, and survival were compared using Kaplan-Meier estimates at 5 years. RESULTS: Median aneurysm size was 5.5 cm. The two-way comparison showed that 5 years after EVAR, patients with small aneurysms (<5.5 cm) had a lower AAA-related death rate (1% vs 6%, P = .006), a higher survival rate (69% vs 57%, P = .0002), and a lower secondary intervention rate (25% vs 32%, P = .03) than patients with large aneurysms (> or =5.5 cm). Three-way analysis revealed that patients with small AAAs (<5.0 cm) were younger (P < .0001) and were more likely to have a family history of aneurysm (P < .05), prior coronary intervention (P = .003), and peripheral occlusive disease (P = .008) than patients with larger AAAs. Patients with smaller AAAs also had more favorable aortic neck anatomy (P < .004). Patients with large AAAs were older (P < .0001), had higher operative risk (P = .01), and were more likely to have chronic obstructive pulmonary disease (P = .005), obesity (P = .03), and congestive heart failure (P = .004). At 5 years, patients with small AAAs had better outcomes, with 100% freedom from rupture vs 97% for medium AAAs and 93% for large AAAs (P = .02), 99% freedom from AAA-related death vs 97% for medium AAAs and 92% for large AAAs (P = .02) and 98% freedom from conversion vs 92% for medium AAAs and 89% for large AAAs (P = .01). Survival was significantly improved in small (69%) and medium AAAs (68%) compared to large AAAs (51%, P < .0001). Multivariate Cox proportional hazards modeling revealed that aneurysm size was a significant independent predictor of rupture (P = .04; hazard ratio [HR], 2.195), AAA-related death (P = .03; HR, 2.007), surgical conversion (P = .007; HR, 1.827), and survival (P = .001; HR, 1.351). There were no significant differences in secondary intervention, endoleak, or migration rates between small, medium, and large AAAs. CONCLUSIONS: Preoperative aneurysm size is an important determinant of long-term outcome following endovascular repair. Patients with small AAAs (<5.0 cm) are more favorable candidates for EVAR and have the best long-term outcomes, with 99% freedom from AAA death at 5 years. Patients with large AAAs (> or =6.0 cm) have shorter life expectancy and have a higher risk of rupture, surgical conversion, and aneurysm-related death following EVAR compared to patients with smaller aneurysms. Nonetheless, 92% of patients with large AAAs are protected from AAA-related death at 5 years. Patients with AAAs of intermediate size (5 to 6 cm) represent most of the patients treated with EVAR and have a 97% freedom from AAA-related death at 5 years.  相似文献   

7.
PURPOSE: The study was conducted to determine the outcome in the United States after endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) in patients at high-risk for open surgery by using independently audited, high-compliance, chart-verified data sets, and to compare those results with open surgery. METHODS: High-risk was defined to match a recent European trial (EVAR2) and included age of > or =60 years with aneurysm size of > or =5.5 cm, plus at least one cardiac, pulmonary, or renal comorbidity. Data from five multicenter investigational device exemption clinical trials leading to Food and Drug Administration (FDA) approval were analyzed. Of 2216 EVAR patients, 565 met the high-risk criteria. Of 342 surgical controls (OPEN), 61 met high-risk criteria. Primary outcome comparisons included AAA-related death, all-cause death, and aneurysm rupture. Secondary measures were endoleak, AAA sac enlargement, and migration. RESULTS: Average age of the high-risk EVAR subset was 76 +/- 7 years vs 74 +/- 6 years OPEN (P = 0.07), mean EVAR AAA size was 6.4 +/- 0.8 cm vs 6.6 +/- 1.0 cm OPEN (P = .33), and average EVAR follow-up was 2.7 years vs 2.5 years OPEN. The 30-day operative mortality was 2.9% in EVAR vs 5.1% in OPEN (P = .32). The AAA-related death rate after EVAR was 3.0% at 1 year and 4.2% at 4 years compared with 5.1% at both time points after OPEN (P = .58). Overall survival at 4 years after EVAR was 56% vs 66% in OPEN (P = .23). After treatment, EVAR successfully prevented rupture in 99.5% at 1 year and in 97.2% at 4 years. CONCLUSIONS: Endovascular repair of large infrarenal AAAs in anatomically suited high-surgical-risk patients using FDA-approved devices in the United States is safe and provides lasting protection from AAA-related mortality. EVAR mortality remained comparable with OPEN up to 4 years. The decision to treat AAAs in patients with advanced age and significant comorbidities must be individualized and carefully considered, but repair provides excellent protection from AAA-related death.  相似文献   

8.
Our objective was to analyze the growth pattern of 4-4.9 cm infrarenal abdominal aortic aneurysms (AAAs). We used an observational, longitudinal, prospective study design. We followed 4-4.9 cm AAAs with 6-monthly abdominal computed tomographic (CT) scans (January 1988-August 2004). AAA growth was defined as an increase in aortic diameter > or =2 mm in each surveillance period. We established the aortic expansion pattern in AAA with three or more CT scans as continuous, discontinuous. The latter includes at least one period of nongrowth (<2 mm/6 months). We studied the influence of cardiovascular risk factors (CVRFs), comorbidity, and AAA anatomical characteristics using the chi-squared test, t-test, life tables, and Kaplan-Meier for statistical analysis. We included 195 patients: 183 (93.8%) men, age 71 +/- 8.3 years (50-90). The follow-up period was 50 +/- 36.4 months (6.5-193.7). The growth pattern (n =131) was continuous in 15 (11.5%) and discontinuous in 116 (88.5%) AAA. The mean expansion rate was higher in AAAs with continuous expansion (7.92 +/- 3.74 vs. 2.74 +/- 2.94 mm/year, p < 0.0001). No CVRFs or comorbidity influenced the expansion pattern (p > 0.05). The eccentric thrombus was associated with a greater incidence of continuous growth (p = 0.05), with no influence of aortic calcification (p > 0.1). The expansion of 4-4.9 cm AAA is mostly irregular and unpredictable. We have not found any modifiable risk factors which influence their growth pattern. The eccentric distribution of the thrombus is associated with continuous expansion.  相似文献   

9.
INTRODUCTION: Mortality from ruptured abdominal aortic aneurysm (AAA) remains high and has given impetus to screening. Targeted screening towards high-risk groups would increase efficacy. Relatives of previous AAA patients have been suggested as one such group. The aim of this study was therefore to determine the prevalence of AAA in relatives of previous patients in Northern Ireland. PATIENTS AND METHODS: All living AAA patients, who underwent surgery between August 2001 and December 2005 in our unit, or were attending for follow-up of small aneurysms were contacted and asked for details of siblings and their family history. Screening by ultrasound was offered to the siblings and children over 50 years, with a defining threshold diameter for an aneurysm of 3.0 cm. Overall prevalence of AAA in the relatives was calculated. Separate prevalence rates were calculated according to relationship and gender of the patient and relative. RESULTS: 513 previous patients were contacted. 132 gave details of living relatives, resulting in a total of 405 relatives suitable for screening. 105 declined a scan, leaving 300 in the study. Overall mean age of the group was 63.0+/-8.7 years and 68% were siblings of male patients. Overall ten AAAs were detected by screening, giving a prevalence of 3.3%. No aneurysms were found in the subgroup of children, while the highest prevalence (12.5%) was found in brothers of female patients. 20 additional AAAs were reported in these 132 families, resulting in 14 of the 132 families (10.6%) having two or more members with AAA. CONCLUSION: The prevalence of screening detected AAA in this study is lower than anticipated. The reason is unclear, but demonstrates the multifactorial nature of the aetiology and genetic complexities yet to be unravelled by future research.  相似文献   

10.
Yusuf K  Murat B  Unal A  Ulku K  Taylan K  Ozerdem O  Erdal Y  Tahsin Y 《Surgery》2007,141(1):83-89
BACKGROUND: Inflammatory abdominal aortic aneurysms (AAAs) are relatively rare clinical entities. The aim of this study is to ascertain the risk factors in patients with inflammatory AAAs and clarify which feature plays a role in determining the long-term outcome in these patients. METHODS: Between 1990 and 1997, 238 patients underwent surgery for an AAA at our institution, 17 (7.1%) of whom had the diagnosis of inflammatory type AAA. This group was matched in a case-control fashion to a group of 35 patients with similar characteristics of age, gender, and preoperative risk factors who were operated on for a noninflammatory AAA. All available clinical, pathologic, and postoperative variables were retrospectively reviewed, and the 2 groups were compared. In the inflammatory group, risk factor analysis was performed for poor outcome. RESULTS: All operations were performed through a standard transperitoneal median laparotomy. The 2 groups did not differ significantly in terms of clinical characteristics and preoperative risk factors Patients with inflammatory AAAs were significantly more symptomatic (100% vs 31%, P = .03) and had larger aneurysm size on admission (8.2 +/- 1.2 cm vs 6.1 +/- 0.4 cm, P = .04). In inflammatory AAAs, preoperative erythrocyte sedimentation rate was found to be significantly elevated (mean, 48 +/- 14 mm/h vs 8 +/- 3 mm/h, P = .01). Surgical morbidity and mortality rates did not differ between 2 groups. The intensive care unit and hospital stay periods were similar in both groups (2.2 days vs 1.8 days, P = .25, and 9.2 days vs 8.1 days, P = .35). Eight-year survival rates of inflammatory and noninflammatory groups were 60% and 74%, respectively (P = .01). Results from Cox proportional hazards model analysis showed that a high sedimentation rate after surgical intervention (P = .02), cardiovascular disease (P = .01), postoperative persisting fibrosis with ureteral entrapment (P = .01), and postoperative chronic renal failure (P = .02) were independent risk factors for death. Other surgical variables did not prove to be risk factors for long-term mortality. CONCLUSIONS: Although the preoperative characteristics may differ in patients with inflammatory type AAAs, they can be treated today with low morbidity and mortality rates. However, inflammatory process may continue postoperatively because of unknown reasons, and the study documented that persisting, postoperative inflammatory process with or without retroperitoneal fibrosis may place a patient at high risk for poor outcome. This is important information for the long-term management of these patients, and we believe that their follow-up protocols should be more comprehensive to further improve their long-term survival rates.  相似文献   

11.
OBJECTIVE: The purpose of this study was to analyze anatomic characteristics of patients with ruptured abdominal aortic aneurysms (AAAs), with conventional two-dimensional computed tomography (CT), including comparison with control subjects matched for age, gender, and size. METHODS: Records were reviewed to identify all CT scans obtained at Dartmouth-Hitchcock Medical Center or referring hospitals before emergency AAA repair performed because of rupture or acute severe pain (RUP group). CT scans obtained before elective AAA repair (ELEC group) were reviewed for age and gender match with patients in the RUP group. More than 40 variables were measured on each CT scan. Aneurysm diameter matching was achieved by consecutively deleting the largest RUP scan and the smallest ELEC scan to prevent bias. RESULTS: CT scans were analyzed for 259 patients with AAAs: 122 RUP and 137 ELEC. Patients were well matched for age, gender, and other demographic variables or risk factors. Maximum AAA diameter was significantly different in comparisons of all patients (RUP, 6.5 +/- 2 cm vs ELEC, 5.6 +/- 1 cm; P <.0001), and mean diameter of ruptured AAAs was 5 mm smaller in female patients (6.1 +/- 2 cm vs 6.6 +/- 2 cm; P =.007). Two hundred patients were matched for diameter, gender, and age (100 from each group; maximum AAA diameter, 6.0 +/- 1 cm vs 6.0 +/- 1 cm). Analysis of diameter-matched AAAs indicated that most variables were statistically similar in the two groups, including infrarenal neck length (17 +/- 1 mm vs 19 +/- 1 mm; P =.3), maximum thrombus thickness (25 +/- 1 mm vs 23 +/- 1 mm, P =.4), and indices of body habitus, such as [(maximum AAA diameter)/(normal suprarenal aorta diameter)] or [(maximum AAA diameter)/(L3 transverse diameter)]. Multivariate analysis controlling for gender indicated that the most significant variables for rupture were aortic tortuosity (odds ratio [OR] 3.3, indicating greater risk with no or mild tortuosity), diameter asymmetry (OR, 3.2 for a 1-cm difference in major-minor axis), and current smoking (OR, 2.7, with the greater risk in current smokers). CONCLUSIONS: When matched for age, gender, and diameter, ruptured AAAs tend to be less tortuous, yet have greater cross-sectional diameter asymmetry. On conventional two-dimensional CT axial sections, it appears that when diameter asymmetry is associated with low aortic tortuosity, the larger diameter on axial sections more accurately reflects rupture risk, and when diameter asymmetry is associated with moderate or severe aortic tortuosity, the smaller diameter on axial sections more accurately reflects rupture risk. Current smoking is significantly associated with rupture, even when controlling for gender and AAA anatomy.  相似文献   

12.
Purpose: The purpose of this study was to clarify the treatment of patients with small abdominal aortic aneurysms (AAAs) less than 5 cm in diameter and those believed to be unfit for operation with AAAs 5 cm diameter or greater.Methods: Four hundred ninety two patients with AAAs less than 5 cm when first seen were entered in a prospective measurement program by ultrasonography or computed tomography scan (exclusively after 1988) every 6 months. A decision regarding operative fitness was made when the AAA was 5 cm. Patients then underwent operation if fit or continued follow-up if their AAA was larger than 5 cm but they were unfit. A further group of 91 patients with aneurysms 5 cm or greater when first seen but unfit for repair were entered in the prospective measurement program.Results: In the group with AAAs less than 5 cm at entry, operation was performed in 201 patients as a result of increase in AAA size to 5 cm or greater (157), AAA expansion of more than 0.5 cm in 6 months (24), or for other reasons (20). Of those with AAAs smaller than 5 cm at entry, 291 have not undergone operation at a mean follow-up of 42 months. Expansion was significantly related to aneurysm size at entry and was highest in the 4.5 to 4.9 cm group at 0.7 cm/year. In the group of patients deemed unfit for operation with 5 cm AAAs [as a graduate of the less than 5 cm group at entry (85 patients) or first seen with AAA greater than 5 cm (91 patients)], 10 ruptures have occurred. Of these patients with ruptured AAAs, six had AAAs between 5.0 and 5.6 cm.Conclusions: Because of the risk of rupture demonstrated in our series in AAAs 5 cm or slightly greater and the progressive increase in expansion to a mean of 0.7 cm/year in those AAAs between 4.5 and 4.9 cm at entry, recommendation for elective operation in patients with AAAs between 4.5 and 5.0 cm should be strongly considered in a fit patient. (J VASC SURG1996;23:213-22.)  相似文献   

13.
OBJECTIVE: Small abdominal aortic aneurysms (AAAs; 4-5.4 cm) are more likely to be suitable for endovascular aneurysm repair (EVAR) than large aortic aneurysms (>5.5 cm). The purpose of this study was to determine whether small AAA growth is associated with the development of morphologic characteristics that decrease eligibility for EVAR. METHODS: We studied 54 patients who underwent 2 or more computed tomography scans with 3-dimensional reconstruction during surveillance of small AAAs. Morphologic aortic aneurysm features and changes were measured according to Society for Vascular Surgery reporting standards. Suitability for EVAR was determined by neck anatomy (diameter, length, and angulations), iliac artery morphology, and total aortic aneurysm angulation and tortuosity. RESULTS: The median age of the study cohort was 73 years (interquartile range [IQR], 65-77 years). The median follow-up period was 24 months (IQR, 15-36 months). The median small AAA diameter increased from 44.5 mm (IQR, 41-48 mm) to 48.9 mm (IQR, 45.7-52.0 mm). The median aortic neck diameter increased from 23.0 to 24.0 mm (P = .002), whereas median neck length decreased from 26.5 to 20.0 mm (P = .001). Aortic aneurysm median tortuosity index increased from 1.09 to 1.11 (P = .05). No significant changes in iliac artery morphology occurred. Overall, the anatomic suitability for endovascular repair did not significantly change during the study period (74% vs 69%; McNemar test; P = .25). CONCLUSIONS: Changes in aortic morphology are frequently associated with small AAA growth at mid-term follow-up, but such changes are minor and do not affect overall anatomic suitability for EVAR. These data reveal that continued surveillance of small AAAs does not threaten the window of opportunity for EVAR.  相似文献   

14.
OBJECTIVE: small abdominal aortic aneurysms (AAAs) do rupture and only half of AAAs above 5 cm would have ruptured unoperated. Furthermore, conservative treatment of AAAs may cause psychological side effects and impaired quality of life. To optimise the indication and time for operation for AAAs, we analysed whether serum elastin peptides (EP), procollagen-IIIN-terminal propeptide (PIIINP), and the initial AAA size could predict operation for AAAs in initially conservatively treated AAA. MATERIAL AND METHODS: in 1994, 4404 65-73 year old males were invited to hospital-based screening for AAAs by ultrasonography. Seventy-six percent attended. One hundred and forty-one (4.2%) had AAAs (def: +30 mm). Nineteen were offered operation (AAA +50 mm), and 112 were followed with annual control scans for 1-5 years (mean 2.5 years). Of these, 99 had their EP (ng/ml) and PIIINP (ng/ml) determined using ELISA and RIA techniques. Two observers and one scanner were used. RESULTS: the mean expansion rate was 2.7 mm/year. The initial AAA size (r =0.46; 0.26-0.61), EP ( r =0.31; 0.11-0.49), and NPIIIP ( r =0.24; 0.02-0.44) was independently significant associated to expansion rate in a multiple linear regression analysis including the three mentioned variables. The multivariate formula could by ROC curve analysis predict cases reaching 5 cm in diameter within 5 years with a sensitivity and specificity of 91% and 87%, respectively, increasing to 91% and 94%, respectively, by accepting a 2 mm variation in those measurements. Twenty-three were lost to follow up, 21 of these due to death or severe illness. Of these, seven would have been predicted to reach an AAA size recommendable for surgery. If all 23 were included in the analysis, the sensitivity and specificity would have been 87% and 85%, respectively. CONCLUSION: a predictive model using EP, PIIINP, and initial AAA size seems capable of predicting nine out of 10 AAAs that will be operated on within 5 years. However, a larger sample size is needed for clinical recommendations.  相似文献   

15.
Abstract The objective of this study was to determine epidemiology and mortality statistics for abdominal aortic aneurysms (AAAs) in Hong Kong. Data from three sources were obtained and analyzed: (1) Hong Kong Hospital Authority discharge statistics for 1999 and 2000; (2) a survey on aortic aneurysms in public hospitals conducted by the Working Group of Vascular Surgery; and (3) the Department of Surgery, University of Hong Kong Medical Center aortic aneurysm database. The disease pattern, distribution, and operative mortality were determined. The annual incidence of AAA in Hong Kong is 13.7 per 100,000 population and 105 per 100,000 for those aged 65 and above. About 10% of the AAAs that presented were ruptured. The mean age of the AAA patients was 74 years, with 84% of them over age 65. The operative repair rate for AAAs was low, being only 8% for intact aneurysms and 54% for ruptured ones. Overall, 45% of all aneurysm repairs were performed for a ruptured AAA. There is diverse practice between major vascular centers and smaller regional hospitals. The territory-wide operative mortality rates for intact and ruptured aneurysms were 10% (range 4–24%) and 70% (range 38––100%), respectively. There was no gender bias in the rupture and operative rates. The overall mortality was 17% for intact AAAs and 78% for ruptured AAAs. The average length of hospital stay was 19 days for elective AAA surgery and 13 days for ruptured AAAs. The number of operations in high-volume centers is increasing with a concomitant decrease in operative mortality. There are no definitive data to indicate that the incidence of AAAs is rising, but a trend toward an increasing number of operations in referral centers is noted. The low repair rates for intact AAAs and the high proportion of repairs for ruptured aneurysms suggest that AAAs are undertreated in Hong Kong.  相似文献   

16.
OBJECTIVES: to investigate the activity of matrix metalloproteinase (MMP)-2 and -9 in asymptomatic abdominal aortic aneurysms (aAAAs) and ruptured abdominal aortic aneurysms (rAAAs). DESIGN: cross-sectional study. MATERIALS AND METHODS: MMP-2 and MMP-9 activity was estimated in biopsies from the anterior wall of 60 AAAs using gelatin zymography. There were 20 medium-sized (diameter 5<7 cm) aAAAs, 20 large (>57 cm) aAAAs and 20 rAAAs. MMP activity was quantified using a laser densitometer and expressed as arbitrary units (au). RESULTS: mean (SEM) MMP-9 activity was significantly lower in large aAAAs (1190 au +/-247) than in rAAAs (2647 au +/-498, p<0.05). There was no difference in MMP-2 activity. CONCLUSION: High MMP-9 activity in the AAA wall is associated with rupture.  相似文献   

17.
OBJECTIVE: The purpose of this study was to evaluate and compare the biomechanical properties of abdominal aortic aneurysm (AAA) wall tissue from patients who experienced AAA rupture with that of those who received elective repair. METHODS: Rectangular, circumferentially oriented AAA wall specimens (approximately 2.5 cm x 7 mm) were obtained fresh from the operating room from patients undergoing surgical repair. The width and thickness were measured for each specimen by using a laser micrometer before testing to failure with a uniaxial tensile testing system. The force and deformation applied to each specimen were measured continuously during testing, and the data were converted to stress and stretch ratio. The tensile strength was taken as the peak stress obtained before specimen failure, and the distensibility was taken as the stretch ratio at failure. The maximum tangential modulus and average modulus were also computed according to the peak and average slope of the stress-stretch ratio curve. RESULTS: Twenty-six specimens were obtained from 16 patients (aged 73 +/- 3 years [mean +/- SEM]) undergoing elective repair of their AAA (diameter, 7.0 +/- 0.5 cm). Thirteen specimens were resected from nine patients (aged 73 +/- 3 years; P = not significant in comparison to the electively repaired AAAs) during repair of their ruptured AAA (diameter, 7.8 +/- 0.6 cm; P = not significant). A significant difference was noted in wall thickness between ruptured and elective AAAs: 3.6 +/- 0.3 mm vs 2.5 +/- 0.1 mm, respectively (P < .001). The tensile strength of the ruptured tissue was found to be lower than that for the electively repaired tissue (54 +/- 6 N/cm2 vs 82 +/- 9.0 N/cm2; P = .04). Considering all specimens, no significant correlation was noted between tensile strength and diameter (R = -0.10; P = .55). Tensile strength, however, had a significant negative correlation with wall thickness (R = -0.42; P < .05) and a significant positive correlation with the tissue maximum tangential modulus (R = 0.76; P < .05). CONCLUSIONS: Our data suggest that AAA rupture is associated with aortic wall weakening, but not with wall stiffening. A widely accepted indicator for risk of aneurysm rupture is the maximum transverse diameter. Our results suggest that AAA wall strength, in large aneurysms, is not related to the maximum transverse diameter. Rather, wall thickness or stiffness may be a better predictor of rupture for large AAAs.  相似文献   

18.
OBJECTIVE: Recent reports have raised concern about the percentage of enlarging abdominal aortic aneurysms (AAAs) after endovascular repair with the Gore Excluder device. As part of the investigation into this issue, a morphologic analysis was performed on enlarging aneurysms in the Excluder Pivotal clinical trial. METHODS: Computed tomographic scans were evaluated on all patients identified with enlarging aneurysms (5-mm increase by Core laboratory or site) and at least 4 years of follow-up in the Excluder Pivotal clinical trial. Three-dimensional reconstruction, a set of 24 standard morphologic measurements, and analysis of potential enlargement mechanisms were performed. RESULTS: Of 112 trial patients with 4 years of follow-up, 38 AAAs (34%) were identified as enlarging. Data were obtained from 196 computed tomographic scans (the mean interval was 47 months from first to last scan). Of the 158 scans with a prior scan for comparison, 41% demonstrated growth relative to the initial scan by diameter criteria, but 79% demonstrated growth relative to the initial scan by 3-dimensional volume criteria (P < .0001 vs diameter; chi2 analysis). This difference was most evident at early time points: at 1 year, diameter criteria indicated that 8% of these AAAs were enlarging, but 56% were already enlarging by volume criteria. On average, enlargement was detected by volume 18 months before it was detected by diameter (P < .0001), and at a smaller diameter (55 +/- 1 mm vs 60 +/- 1 mm; P < .0001). Only 19% of scans (39% of patients) had apparent endoleaks. Scans with apparent endoleaks demonstrated a greater interval rate of growth as compared with those without apparent endoleak (3.6 +/- 0.8 mm vs 1.9 +/- 0.3 mm [P < .02] by diameter; 23 +/- 4 cm3 vs 11 +/- 1 cm3 [P < .001] by volume). Although the etiology of enlargement may be endotension or device permeability in up to 74% of patients, other potential causes of aneurysm enlargement included neck apposition length less than 15 mm (15 patients; 39%), large aortic diameter relative to device (18%), large iliac diameter (5%), and iliac apposition length less than 15 mm (20%). Multiple potential etiologies of enlargement were present in 53% of AAAs. CONCLUSIONS: The etiology of aneurysm enlargement in the Excluder Pivotal trial is likely multifactorial, including endoleak, inadequate attachment site length, and endotension or device permeability. Even by conservative criteria, a substantial percentage of aneurysm growth with the original device is likely due to material permeability. Three-dimensional volume criteria detected aneurysm enlargement more frequently, at a smaller diameter, and on average 18 months sooner than standard diameter criteria, thus suggesting a role in further investigation of this issue.  相似文献   

19.
AIM: Abdominal aortic aneurysms (AAAs) larger than 5.5 cm should generally undergo elective repair. However, some of these patients have serious comorbid conditions, which greatly increase operative risk. This study evaluated the outcomes of nonoperative, observational management and selective delayed AAA repair in high-risk patients with large infrarenal and pararenal AAAs. METHODS: Among 226 patients with AAAs >5.5 cm, we selected 72 with AAAs 5.6-12.0 cm (mean 7.0 cm) for periods of nonoperative management because of their prohibitive surgical risks. Comorbid factors included a low ejection fraction of 15-34% (mean 22%) in 18 patients; FEV1 <50% (mean 38%) in 25; prior laparotomy in 10; and morbid obesity in 22. Follow-up was complete in the 72 patients for the 6-76 months (mean 23 months) that they were treated nonoperatively. Fifty-three patients ultimately underwent repair because of AAA enlargement or onset of symptoms after 6-72 months (mean 19 months) of observational treatment. RESULTS: Of the 72 selected patients, 54 (75%) are living and 18 (25%) are dead. Seven patients undergoing only nonoperative treatment presently survive after 28-76 months (mean 48 months). Of the 18 deaths, AAA rupture occurred in only 3 patients (4%) who had been observed for 12, 31, and 72 months before rupture. Nine other deaths (13%) occurred after 6-72 months from comorbidities unrelated to the patient's AAA. Six of the 53 patients undergoing delayed AAA repair died within 30 days of operation (11% mortality). The mortality for the 154 good risk AAA patients, who underwent prompt open or endovascular repair, was 2.2%. CONCLUSION: These data indicate that some patients with large AAAs and serious comorbidities are acceptably managed for long periods (6-76 months) by nonoperative means. Substantial delays of 12 to 76 months resulted in an AAA rupture rate of only 4%, while 13% of these patients (9 of 72) died of their comorbidities unrelated to AAA rupture or surgery and mortality in this group of patients, when operated on, was 11% (6 of 53). These findings support the selective use of nonoperative observational management in some patients with large AAAs and serious comorbidities.  相似文献   

20.
OBJECTIVES: In the absence of formal screening abdominal aortic aneurysms (AAA) are detected in an opportunistic manner. Many remain asymptomatic and undetected until they rupture. Incidentally discovered small AAAs are entered into a surveillance programme until they reach a suitable size for repair. The aim of this study was to examine trends in the management of AAA and whether the method of presentation had an effect on subsequent mortality. DESIGN: Observational study in UK district general hospital. MATERIALS/METHODS: This study reports a single surgeon case series identified using a prospectively maintained database. Data on mode of presentation, management and mortality were retrieved from case notes, PIMS hospital database and the Office of National Statistics. RESULTS: Two hundred and five patients were referred with AAAs between 1992 and 2004, 78% presenting in elective circumstances. The surveillance programme fed 33% of the operated cases. Two aneurysms ruptured whilst under surveillance. Overall elective operative mortality was 11.8% and has progressively decreased over time. Thirty-day operated mortality was significantly lower in patients having a period of surveillance than those having immediate elective repair (2.3 vs. 16.3%, p=0.018). A slight reduction in emergency AAA repairs was noted over the study period (r2=0.6) although registered aneurysm deaths continue to increase (r2=0.83). CONCLUSIONS: Elective mortality following AAA surgery decreased over the study period. Outcome was better in those patients who had surgery for aneurysms that had been under surveillance. Despite opportunistic screening the population adjusted mortality rate of aortic aneurysms showed a progressive increase. A reduction in deaths from aneurysms is unlikely without a formal screening programme.  相似文献   

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