Management of symptomatic abdominal aortic aneurysms following emergency computed tomography

Purpose

It is still difficult to determine the appropriate timing of surgery for a symptomatic abdominal aortic aneurysm (AAA). Since recent developments in computed tomography (CT) have made the procedure substantially less time-consuming, we used CT on patients with symptomatic AAA to determine the most appropriate management option.

Methods

CT was performed on 79 patients with symptomatic AAA. If rupture of the AAA was confirmed by CT, patients underwent emergency surgery. If there was no rupture, patients were observed in an intensive care unit, and surgery was scheduled according to the results of repeated CT (2.1 times on average) and physical examinations, as well as on their clinical signs and symptoms.

Results

By CT, we identified 42 ruptures, one contained rupture, one aortocaval fistula, five acute aortic dissections with AAAs, six inflammatory AAAs, six pseudoaneurysms and 18 non-ruptured AAAs. The mortality rate of the patients with ruptures was 33 %. For the 37 patients without rupture, as determined by CT, three emergency, nine urgent, and 20 elective operations were performed. Two patients who refused surgery experienced late rupture and died. Among the other 35 patients, the mortality rate was 6 %.

Conclusion

CT was an effective modality to classify patients with symptomatic AAA into those who needed emergency surgery and those who did not. We could observe patients with symptomatic non-ruptured AAAs before urgent/elective operations by repeated CT and monitor the clinical findings.     

Abdominal aortic aneurysm repair in octogenarians: myth or reality?

AIM: We studied the thirty-day mortality and morbidity rate to assess the value of conventional open repair vs endovascular aortic repair (EVAR) in an elderly population presenting with a ruptured, symptomatic or asymptomatic abdominal aortic aneurysm (AAA) undergoing emergency, urgent or elective repair. METHODS: During the period from January 2004 to May 2007, 329 consecutive patients were treated for AAA in our Department. Among these, 81 (24.6%) were aged >80 years (mean age 83.6, range 80-95 years). These older patients were divided into groups according to their clinical presentation: ruptured AAA group (rAAA) - 22 cases (4 emergency EVAR, 18 emergency open repair); symptomatic non-ruptured AAA group (sAAA) - 15 cases (11 urgent EVAR, 4 urgent open repair); asymptomatic AAA group (asAAA) - 44 cases (32 elective EVAR, 12 elective open repair). The main outcome measures were 30-day mortality and 30-day morbidity rate. RESULTS: The mortality rate following open surgery vs EVAR was 66.6% vs 50% (P=NS) in the rAAA group, 25% vs 0% (P=NS) in the sAAA group, and 9% vs 3.2% (P=NS) in the asAAA group. When comparing postoperative morbidities in the octogenarians, 3 of the patients that received EVAR (6.4%) and 15 of those that received open repair (48.4%) had a severe complication (P<0.01). CONCLUSION: The introduction of EVAR has considerably changed the balance of risks and benefits for AAA treatment. Our study confirms the high mortality rate for octogenarians with rAAA and haemodynamic instability, and supports the value of an active EVAR approach for octogenarians with AAA to prevent rupture. Moreover, the introduction of endovascular techniques as part of an overall treatment algorithm for ruptured AAAs appears to be potentially associated with improved outcomes in terms of mortality and morbidity as compared to open surgical repairs alone.     

Abdominal Aortic Aneurysm Wall Mechanics and their Relation to Risk of Rupture

PURPOSE: to see whether aneurysmal aortic wall mechanics can be used as a predictor of abdominal aortic aneurysm (AAA) rupture. METHOD: among 285 individuals, followed conservatively for AAA and monitored for aneurysm growth and wall mechanics on at least one occasion at our institution between January 1991 and January 1998, eleven subsequently ruptured. Wall mechanics were estimated as stiffness (beta). This was calculated from diameter and pulsatile diameter change, determined non-invasively by an ultrasonic echo-tracking system and blood pressure obtained by the auscultatory method. The results were compared with those of 121 individuals electively operated on for AAA. RESULTS: no difference in aortic stiffness was found between those that subsequently ruptured (beta=35, median) compared to those non-ruptured (beta=38, median) AAAs (p=0.855). There was no difference in diameter in ruptured (58.8 mm) compared with non-ruptured (54.1 mm) AAAs (p=0.129). All ruptured AAAs showed an expansion of diameter over time. CONCLUSION: this study shows no difference in aneurysmal aortic wall mechanics in those AAAs that subsequently ruptured compared with electively operated AAAs. The results indicate that it is not possible to use aneurysmal aortic wall stiffness as a predictor of rupture.     

Elevated plasma MMP1 and MMP9 are associated with abdominal aortic aneurysm rupture.

BACKGROUND: The role of matrix metalloproteinases (MMPs) in abdominal aortic aneurysm (AAA) formation is well established. However the changes in plasma MMP levels with AAA rupture have not been reported. The aim of this study was to determine circulating levels of MMPs in non-ruptured and ruptured AAA immediately prior to open repair. METHODS: Concentrations of MMPs and their endogenous tissue inhibitors (TIMPs) were quantified using ELISA in pre-operative plasma samples from non-ruptured and ruptured AAA. RESULTS: MMP1 and MMP9 were elevated in the plasma of ruptured AAA versus non-ruptured AAA. A four-fold elevation in pre-operative plasma MMP9 was associated with non-survival at 30 days from rupture surgery compared with those surviving for greater than 30 days. CONCLUSION: In conclusion, these findings support the role of MMPs in AAA pathogenesis. Elevation of MMP9 was associated with ruptured aneurysm related 30-day mortality and may represent a survival indicator in this group.     

Emergency Non-ruptured Abdominal Aortic Aneurysm

OBJECTIVES: To investigate symptoms and early mortality (<30 days) following open surgery for emergency, symptomatic non-ruptured abdominal aortic aneurysm (AAA). DESIGN: Retrospective cohort study. PATIENTS AND METHODS: During the period 1983-1994, 129 patients had an emergency admission, followed by surgery, for symptomatic non-ruptured AAA. Sixty-one received surgery within 24 h of admission and 68 received surgery more than 24 h after admission (median 135 h, inter-quartile range: 51-239 h). During the same period 239 patients had elective surgery for non-ruptured AAA. Early mortality (<30 days), symptoms and co-morbidities were recorded. Data were retrieved from the patient records. RESULTS: Mortality (30 days) was 18% in the 61 patients having surgery within 24 h of emergency admission for non-ruptured AAA. Mortality following either delayed surgery (semi-elective) after emergency admission or elective surgery was 4.2% (p=0.0002). Four out of 11 patients who died within 30 days following an acute operation had previously been declared unfit for elective surgery. One additional emergency patient had been found unfit for open surgery, but survived a delayed operation. CONCLUSION: The high mortality rate of patients with non-ruptured, symptomatic AAA undergoing surgery within 24 h of admission appears to be influenced by several factors, including co-morbidities and the acute operation. We propose that the 30-day mortality for non-ruptured AAA should be reported in two categories: mortality rate for elective surgery and mortality for surgery performed within 24 h of emergency admission. The term 'emergency non-ruptured' is a suitable term for the latter group.     

Biomechanical Rupture Risk Assessment of Abdominal Aortic Aneurysms: Model Complexity versus Predictability of Finite Element Simulations

ObjectiveInvestigation of the predictability of finite element (FE) models regarding rupture risk assessment of abdominal aortic aneurysms (AAAs).Materials and materialsPeak wall stress (PWS) and peak wall rupture risk (PWRR) of ruptured (n = 20) and non-ruptured (n = 30) AAAs were predicted by four FE models of different complexities derived from computed tomography (CT) data. Two matching sub-groups of ruptured and non-ruptured aneurysms were used to investigate the usability of different FE models to discriminate amongst them.ResultsAll FE models exhibited a strong positive correlation between PWS and PWRR with the maximum diameter. FE models, which excluded the intra-luminal thrombus (ILT) failed to discriminate between ruptured and non-ruptured aneurysms. The predictability of all applied FE models was strengthened by including wall strength data, that is, computing the PWRR. The most sophisticated FE model applied in this study predicted PWS and PWRR 1.17 (p = 0.021) and 1.43 (p = 0.016) times higher in ruptured than diameter-matched non-ruptured aneurysms, respectively.ConclusionsPWRR reinforces PWS as a biomechanical rupture risk index. The ILT has a major impact on AAA biomechanics and rupture risk, and hence, needs to be considered in meaningful FE simulations. The applied FE models, however, could not explain rupture in all analysed aneurysms.     

Trends in mortality and hospital admission rates for abdominal aortic aneurysm in England and Wales, 1979-1999

BACKGROUND: The aim of this study was to investigate trends in population-based mortality, hospital admission and case fatality rates for abdominal aortic aneurysm (AAA) from 1979 to 1999. METHODS: This was an analysis of routine statistics from 79 495 death certificates in England and Wales and 3217 hospital inpatient admissions in the Oxford Region. RESULTS: Mortality rates for all AAAs increased between 1979 and 1999 from 13 to 25 per million in women and from 80 to 115 per million in men. Admission rates increased in the same time interval from three to 22 admissions per million per year in women, and from 52 to 149 per million per year in men. Case fatality rates for all non-ruptured AAAs that were operated on decreased from 25.8 to 9.0 per cent and for all ruptured AAAs from 69.9 to 54.4 per cent. CONCLUSION: Mortality rates and hospital admission rates for AAA rose in men and even more so in women between 1979 and 1999. Perioperative mortality for ruptured AAA declined a little during the study but nonetheless was still very high at the end. This reinforces the importance of detecting and treating AAA before rupture occurs.     

The cost-effectiveness of early surgery versus watchful waiting in the management of small abdominal aortic aneurysms

Purpose: The purpose of this study was to compare the relative cost-effectiveness of two clinical strategies for managing 4 to 5 cm diameter abdominal aortic aneurysms (AAAs): early surgery (repair 4 cm AAA when diagnosed) versus watchful waiting (monitor AAA with ultrasound size measurements every 6 months and repair if the diameter reaches 5 cm).Methods: We used a Markov decision tree to compute the expected survival in quality-adjusted life years (QALYs) for each strategy, based on literature-derived estimates for the probabilities of different outcomes in this model. We determined hospital costs for patients undergoing elective and emergency AAA repair at our center. With standard methods of cost accounting, we then calculated the additional cost per year of life saved by early surgery compared with watchful waiting (cost-effectiveness ratio, dollars/QALY).Results: Mean hospital costs for elective and emergency AAA repair were $24,020 and $43,208, respectively (1992 dollars). For our base-case analysis (60-year-old men with 4 cm diameter AAAs, with 5% elective operative mortality rate and 3.3% annual rupture rate), early surgery improved survival by 0.34 QALYs compared with watchful waiting, at an incremental cost of $17,404/QALY. Increased elective surgical mortality rate, decreased AAA rupture risk, and increased patient age all reduced the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery.Conclusions: The cost effectiveness of early surgery for 4 cm diameter AAAs in carefully selected patients compares favorably with that of other commonly accepted preventive interventions such as hypertension screening and treatment. With an upper limit of $40,000/QALY as an "acceptable" cost-effectiveness ratio, early surgery appears to be justified for patients 70 years old or younger, if the AAA rupture risk is 3%/year or more and the elective operative mortality rate is 5% or less. Although not a substitute for clinical judgment, this cost-effectiveness analysis delineates the essential tradeoffs and uncertainties in treating patients with small AAAs. (J VASC SURG 1994;19:980–91.)     

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States

BACKGROUND: The hypothesis of this study was that differences exist among patients with private insurance compared with patients with Medicaid or no insurance, regarding access to the timely treatment of abdominal aortic aneurysms (AAAs) and the outcomes of AAA repair. METHODS: The study comprised 5363 patients aged less than 65 years (mean age, 59 years) with a diagnostic code for intact or ruptured AAA and a procedure code for AAA repair in the National Inpatient Sample for 1995 to 2000. Dependent variables included ruptured AAA, intact AAA, and in-hospital postoperative mortality rates. Independent variables included payer status, median income, race, gender, age, and comorbid disease. Risk-adjusted analyses were performed with the use of binary logistic regression. RESULTS: AAA rupture was most likely (P <.001) to affect patients with no insurance (36%) or Medicaid (18%), compared with patients with private insurance (13%). After an adjustment for case-mix had been made, data showed that patients without insurance had an increased risk of rupture compared with patients with private insurance (odds ratio, 2.3; 95% CI, 1.5-3.5; P <.001). Operative mortality rates after elective AAA repair were greater (P =.04) for patients with no insurance (2.6%) or Medicaid (2.7%), compared with patients with private insurance (1.2%). Similarly, operative mortality rates for AAA repair after rupture were greater (P =.001) in patients without insurance (45.3%) or Medicaid (31.3%), compared with patients with private insurance (26.2%). CONCLUSIONS: Uninsured patients more often seek treatment of ruptured AAAs compared with patients with private insurance. Operative mortality rates in uninsured patients are greater for elective and emergent AAA repair. These data support the tenet that payer status is associated with mortality rates after AAA repair.     

Epidemiology and Outcome of Aortic Aneurysms in Hong Kong

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.     

Ultraschallscreening auf abdominale Aortenaneurysmen (AAA)

Background

Abdominal aortic aneurysm (AAA) rupture is associated with a high mortality. The only preventive therapy is early diagnosis and elective surgery of rupture prone AAAs. Using B-mode sonography AAAs can be detected early with great reliability. Thus, a population-based ultrasound screening might lower the risk of abdominal aortic aneurysm ruptures.

Materials and methods

A literature analysis (until June 2014) was performed in the databases of MEDLINE, PubMed, and SCOPUS including all randomized controlled trials (RCT), systematic reviews, meta-analyses, health technology assessments (HTA reports) and medical guidelines on AAA screening. The following keywords were used: abdominal aortic aneurysm, ultrasound screening, evidence, guidelines. Clinically relevant endpoints were the following: AAA-associated mortality, overall mortality, number of elective AAA operations, number of ruptured AAAs and emergency surgery for different follow-up intervals.

Results

In four RCTs men between 65 and 83 years either had a single or no ultrasound examination of the abdominal aorta. Older women were only analyzed in one RCT. The meta-analysis of the RCT results shows that ultrasound screening caused a significant decrease of AAA-associated mortality, number of ruptured abdominal aneurysms, and number of emergency operations, whereas the number of elective surgeries significantly increased. Overall mortality was only moderately decreased by AAA screening.

Conclusion

Evidence was provided in population-based RCTs and meta-analyses for the efficiency of ultrasound based AAA screening for men older than 65 years. Presently the Federal Joint Committee (G-BA) and the Institute for Quality and Efficiency in Health Care (IQWIG) are evaluating a national ultrasound-based AAA screening program for Germany. However, additional clinical trials are necessary to assess risk groups especially men under 65 years, women with nicotine abuse and cardiovascular diseases which were underrepresented in previous studies.     

Rupture of abdominal aortic aneurysm: concurrent comparison of outcome of those occurring after endovascular repair versus those occurring without previous treatment in an 11-year single-center experience

OBJECTIVE: The purpose of this single-center study was to compare findings at presentation and surgical outcome in patients in whom abdominal aortic aneurysms (AAAs) ruptured after endovascular repair and patients in whom AAAs ruptured before any treatment, over a defined period. METHODS: From May 1992 to September 2003, 1043 patients underwent elective repair of intact infrarenal AAAs. Endovascular repair was performed in 609 patients, and open repair in 434 patients. Eighteen of 609 patients (3%) who underwent endovascular AAA repair required treatment because of rupture of the aneurysm after a mean of 29 months (group 1). During the same 11-year period, another 91 patients without previous treatment required urgent repair of a ruptured AAA (group 2). Rupture was diagnosed at contrast material-enhanced computed tomography or by presence of extramural extravasation of blood at open repair. Except for a higher incidence of women in group 2, patients in both groups were similar with regard to demographics and clinical characteristics but differed in findings at presentation. Eight patients in group 1 had a known endoleak before AAA rupture, whereas contrast-enhanced computed tomography, performed in 15 patients at presentation, demonstrated an endoleak in all. Hypotension (systolic blood pressure <100 mm Hg) was noted at presentation in 4 of 18 patients (22%) in group 1 and 76 of 91 patients (84%) in group 2. All patients underwent open repair via a transperitoneal approach, except for 4 patients in group 1 and 3 patients in group 2 who underwent endovascular repair of ruptured AAAs. RESULTS: The proportion of patients with hypotension at presentation in group 1 (4 of 18) was significantly less than in group 2 (76 of 91; P < .01). The difference in perioperative (30 day) mortality rate in group 1 (3 of 18; 16.6%) compared with group 2 (49 of 91; 53.8%) was also significant (P < .01). The outcome in group 1 was therefore superior to that in group 2. CONCLUSIONS: This study confirms that endovascular AAA repair complicated by endoleak does not prevent rupture. The data suggest, however, that rupture, when it occurs in these circumstances, may not be accompanied by such major hemodynamic changes and high mortality as rupture of an untreated AAA. Further long-term follow-up and analysis in a larger group of patients are required to confirm the apparent intermediate level of protection afforded by failed endovascular repair, which does not prevent rupture but enhances survival after operation to treat rupture, possibly by ameliorating the hemodynamic changes associated with the rupture process.     

In vivo analysis of mechanical wall stress and abdominal aortic aneurysm rupture risk

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.     

Long-term survival and late complications after repair of ruptured abdominal aortic aneurysms

Purpose:Long-term survival and late vascular complications in patients who survived repair of ruptured abdominal aortic aneurysms (RAAA) is not well known. The current study compared late outcome after repair of RAAA with those observed in patients who survived elective repair of abdominal aortic aneurysms (AAA). Methods:The records of 116 patients, 102 men and 14 women (mean age: 72.5 (8.3 years), who survived repair of RAAA (group I) between 1980 to 1989 were reviewed. Late vascular complications and survival were compared with an equal number of survivors of elective AAA repair matched for sex, age, surgeon, and date of operation (group II). Survival was also compared with the age and sex-matched white population of west-north central United States. Results:Late vascular complications occurred in 17% (20/116) of patients in group I and in 8% (9/116) in group II. Paraanastomotic aneurysms occurred more frequently in group I than in group II (17 vs. 8,p = 0.004). At follow-up, 32 patients (28%) were alive in group I (median survival: 9.4 years) and 53 patients (46%) were alive in group II (median survival: 8.7 years). Cumulative survival rates after successful RAAA repair at 1, 5, and 10 years were 86%, 64%, and 33%, respectively. These were significantly lower than survival rates at the same intervals after elective repair (97%, 74%, and 43%, respectively, p = 0.02) or survival of the general population (95%, 75%, and 52%, respectively,p < 0.001). Coronary artery disease was the most frequent cause of late death in both groups. Vascular and graft-related complications caused death in 3% (3/116) in group I and 1% (1/116) in group II. Cox proportional hazards modeling identified age p = 0.0001), cerebrovascular disease p = 0.009), and number of days on mechanical ventilation p = 0.01) to be independent prognostic determinants of late survival in group I. Conclusions:Late vascular complications after repair of RAAA were higher and late survival rates lower than after elective repair. These data support elective repair of AAA. As two-thirds of the patients discharged after repair of RAAA are alive at 5 years, aggressive management of RAAA remains justified. (J Vasc Surg 1998;27:813-20.)     

POSSUM models in open abdominal aortic aneurysm surgery.

OBJECTIVES: This study evaluated the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM), Portsmouth (P) POSSUM and Vascular (V) POSSUM. The primary aim was to assess the validity of these scoring systems in a population of patients undergoing elective and emergency open AAA repair. The secondary intention was in the event that these equations did not fit all patients with an aneurysm; a new model would be developed and tested using logistic regression from the local data (Cambridge POSSUM). METHODS: POSSUM data items were collected prospectively in a group of 452 patients undergoing elective and emergency open AAA repair over an eight-year period. The operative mortality rates were compared with those predicted by POSSUM, P-POSSUM, V-POSSUM and Cambridge POSSUM. RESULTS: All models except V-POSSUM (physiology only) showed significant lack of fit when predicting mortality after open AAA surgery. It was found that the locally generated single unified model (Cambridge POSSUM) could successfully describe both elective and ruptured AAA mortality with good discrimination (chi(2)=9.24, 7 d.f., p=0.236, c-index=0.880). CONCLUSIONS: POSSUM, V-POSSUM and P-POSSUM may not be robust tools for comparing mortality between populations undergoing elective and emergency open AAA repair as once thought. The development and successful validation of Cambridge POSSUM provides a unified model to describe both elective and emergency AAAs together and should be validated in other geographical settings.     

Surgical Treatment of Inflammatory Abdominal Aortic Aneurysms: A Long-Term Follow-up of 19 Patients

The prevalence of inflammatory abdominal aortic aneurysms (IAAA) in autopsy material ranges between 2.5 and 10% of all aneurysms. Clinical findings, the distinction between inflammatory and degenerative aneurysms, and epidemiological data are uncertain, and only a few long-term follow-up studies of patients after surgical treatment of IAAAs exist. In this study, 19 patients underwent either emergency or elective surgery for IAAA during the 10-year period between 1983 and 1993 at Helsinki University Central Hospital. Demographics, symptoms, and operative and follow-up data were collected retrospectively with emphasis on the long-term outcome of IAAA. Causes of late death were available from hospital records and the central statistical office of Finland. For survival analysis we compared ruptured versus nonruptured and emergency versus elective cases of IAAAs. Mean follow-up for the 18 surviving patients (1 hospital death) was 7.4 years. One patient (5%) died of a long-term complication of the aneurysmal disease. There was no statistically significant difference in survival rates for emergency versus elective surgery cases or ruptured versus nonruptured aneurysms. The most common cause of late death was myocardial infarction. The hospital stay mortality (5%) and morbidity (31%), and the survival rate of 26% at 5 years for ruptured and 65% and 43% for nonruptured IAAAs at 5 years and 10 years, respectively, are comparable to normal AAA survival rates. These findings show that surgery is recommended, especially as ruptures also occur in this subgroup of aneurysms.     

Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery

BACKGROUND: This study investigated the volume-outcome relationship for abdominal aortic aneurysm (AAA) surgery and quantified critical volume thresholds. METHODS: PubMed, EMBASE and the Cochrane library were searched for articles on the operation volume-outcome relationship in elective and ruptured AAA surgery. UK Hospital Episode Statistics data were also considered. Elective and ruptured AAA repairs were dealt with separately. The data were meta-analysed, and the odds ratios (95 per cent confidence interval) for mortality at higher- and lower-volume hospitals were compared. Volume thresholds were identified from each paper. RESULTS: The analysis included 421,299 elective and 45,796 ruptured AAA operations. Significant relationships between mortality and annual volume were noted for both groups. Overall, the weighted odds ratio was 0.66 (0.65 to 0.67) for elective repair at a threshold of 43 AAAs per annum and 0.78 (0.73 to 0.82) for ruptured aneurysm repair at a threshold of 15 AAAs per annum, both in favour of high-volume institutions. CONCLUSION: Higher annual operation volumes are associated with significantly lower mortality in both elective and ruptured AAA repair. This suggests that AAA surgery should be performed only at higher-volume centres.     

Operative treatment of abdominal aortic aneurysms in octogenarians. When is it too much too late?

OBJECTIVE: This study evaluated the value of operation for treatment of all octogenarians with ruptured abdominal aortic aneurysms (AAA). SUMMARY BACKGROUND DATA: Elective AAA resection in octogenarians is safe, with published operative mortality rates of approximately 5%. Published operative mortality rates of ruptured AAA in this age group, however, vary from 27 to 92%. METHODS: To evaluate this question, we extracted the clinical course of the 34 octogenarians submitted to AAA resection by the authors from our total experience of 548 resections performed during the past 7 1/2 years. In this subgroup of octogenarians, 18 underwent elective AAA replacement, 5 were submitted to urgent resection of active but intact AAAs, and 11 had operations for ruptured AAAs. There were 23 males and 11 females in the group. The ages ranged from 80 to 91 years. RESULTS: Operative mortality in the patients managed electively was 5.6%. Two of the five patients (40%) submitted to operation for active yet unruptured aneurysms died in the preoperative period. Finally, 10 of the 11 patients (91%) with ruptured AAAs were operative mortalities. All of these operative mortalities in the ruptured AAA subgroup had severe hypotension preoperatively (mean systolic blood pressure: 23 mm Hg). The charges associated with the management of the ruptured AAA group averaged $84,486 (range $12,537-$199,233). CONCLUSIONS: Although elective replacement of AAA in properly selected octogenarians appears valuable to prolong worthwhile life expectancy, this experience leads us to consider observation only in the treatment of octogenarians with ruptured AAA who present with severe hemodynamic instability.     

Epidemiological study of the relationship between volume and outcome after abdominal aortic aneurysm surgery in the UK from 2000 to 2005

BACKGROUND: The aim was to assess the relationship between hospital volume and outcome after abdominal aortic aneurysm (AAA) surgery in the UK. METHODS: Hospital Episode Statistics (2000-2005) were classified as elective, urgent or ruptured AAA repair. Analysis was by modelling of mortality rate, complication rate and length of hospital stay with regard to the annual operative volume, after risk adjustment. RESULTS: There were 112,545 diagnoses, or repairs, of AAAs, of which 26,822 were infrarenal aneurysms. The mean mortality rate was 7.4, 23.6 and 41.8 per cent for elective, urgent and ruptured AAA repair respectively. Elective AAA repair undertaken at high-volume hospitals showed volume-related improvements in mortality (P < 0.001). Patients were discharged from hospital earlier (P < 0.001). The critical volume threshold was 32 elective AAA repairs per year. For urgent repair, patients at high-volume hospitals had a reduced mortality rate (P = 0.017) with an increased length of stay (P = 0.041). There was no relationship between volume and outcome for ruptured AAA repairs. CONCLUSION: Increased annual volumes were associated with significant reductions in mortality for elective and urgent AAA repair, but not for repair of ruptured AAAs.     

Aortic necks of ruptured abdominal aneurysms dilate more than asymptomatic aneurysms after endovascular repair

BACKGROUND: Endovascular repair of abdominal aortic aneurysm (AAA) is increasingly used. We evaluated if a difference exists in the rate of change of the aortic neck diameter between non-ruptured and ruptured AAAs after endovascular aneurysm repair (EVAR). METHODS: Details of patients undergoing elective (group I) and emergency (group II) EVAR using Talent stents between October 1999 and September 2005 were reviewed. Top neck diameters were prospectively recorded on the hospital database from computed tomography scans preoperatively and at 1, 3, 12, and 24 months postoperatively. The aortic neck diameter rate of change was calculated for each group. RESULTS: Endovascular repair was performed on 110 elective and 41 emergency patients, of which 100 (80 male) elective and 29 (26 male) emergency patients were included in this analysis. Mean age was similar in each group. Stents were oversized by 20.9% +/- 13.6% in group I and by 24.7% +/- 16.3% in group II (P = .37). The preoperative mean proximal aortic neck was larger in group II (25.0 +/- 3.3 mm vs 23.5 +/- 2.8 mm; P = .029). The growth rate of the top neck diameter was significantly greater at 12 months (1.48 +/- 2.4 mm/year vs 3.89 +/- 6.24 mm/year; P = .04) and 24 months (.99 +/- 1.1 mm/year vs 2.61 +/- 3.3 mm/year; P = .04) in group II than in group I. A decreasing sac size was found in 68.2% of patients whose neck dilated. The complication rate was similar in each group. CONCLUSION: Aneurysm necks in patients with ruptured aneurysms are larger and dilate at a greater rate than those with nonruptured aneurysms. The accelerated rate of expansion in some patients must be borne in mind during follow-up and in secondary endovascular interventions and conversion to open surgery.