Population-based record linkage study of the incidence of abdominal aortic aneurysm in Western Australia in 1985-1994

Combined Aorto-Iliac and Anterior Lumbar Spine Reconstruction: A Case Series

BACKGROUND

Treatment options for aortic-iliac pathology may include endovascular repair and open surgical repair. Treatment options for degenerative disc disease (DDD) are varied but commonly include anterior reconstruction. When both the aortic-iliac and spinal pathologies are significant and surgical intervention is indicated for each pathology, the opportunity exists for concurrent treatment of both the aortic-iliac pathology and DDD in the same operation. The purpose of this case series was to document the safety and feasibility of a surgical strategy whereby a combined elective reconstructive procedure was performed for aortic and anterior lumbar spinal pathologies.

METHODS

The case histories of 5 patients who were treated for both spinal and vascular pathology are presented. Surgical outcome measures included operative time, blood loss, length of stay, and complications. Spine-specific outcome measures included Oswestry Disability Index, Roland Morris Disability Questionnaire, and visual analogue scores (back and leg).

RESULTS

The spinal reconstructions performed included 1 L4-5 total disc replacement (TDR), 1 L4-5, L5-S1 anterior lumbar interbody fusion (ALIF), 1 L5-S1 ALIF, and 2 hybrid procedures (L4-5 TDR with L5-S1 ALIF). Vascular reconstructions included 4 aorto-bi-iliac bypass grafts and 1 aortic tube graft. The average operative time was 365 minutes (ranging between 330 and 510 minutes), the average blood loss was 1699 mL (range between 1160 and 2960 mL), and the average length of hospital stay was 14 days (range from 8 to 22 days). There were no in-hospital complications, and all patients experienced significant improvement in both back and leg pain. One patient developed kinking of the iliac limbs of the vascular graft 1 year postoperatively, which was managed with endovascular stenting of the graft.

CONCLUSIONS

Aortic-iliac pathology and DDD are significant pathologies often treated in isolation. This study illustrates that, despite its complexity, highly trained individuals in a specialized setting can perform combined surgery to achieve a satisfactory outcome for the patient.

LEVEL OF EVIDENCE

Level IV evidence.

Patients with Ruptured Abdominal Aortic Aneurysm Have Become Higher Risk

BACKGROUND

Independent risk factors such as age, loss of consciousness, elevated serum creatinine, low hemoglobin, and electrocardiogram evidence of ischemia have previously been shown to predict mortality after ruptured abdominal aortic aneurysm (rAAA). With an aging Australian population, we sought to determine if patients presenting with rAAA now had more predictive risk factors for mortality and whether these factors remain predictive of mortality.

METHODS

The records of all patients presenting with rAAA between January 1985 to December 1993 (past era, group 1) and January 2007 to December 2011 (modern era, group 2) were retrieved. A database of independent risk factors, repair method, and mortality was constructed. Comparisons were made between the 2 groups, where a P value of < 0.05 was considered statistically significant.

RESULTS

Hundred and eighty-eight patients presented with rAAA in the past era, of which 154 were then prepared for repair. 60 patients presented in the modern group, in which 38 patients were then prepared for repair. Proportionally, more patients in the modern era group were rejected for surgery compared to the past era group, (22/60 vs. 34/188; P = 0.004) Rejection was based on both medical comorbidities as well as patient/family and surgeon preferences. The in-hospital mortality rate for patients undergoing repair remained unchanged between the groups at 39%. Age was the only predictive factor that differed between the modern and past era groups (median age: 81 vs. 72 respectively, P < 0.001). However, this equated to more risk factors per patient in the modern group compared to the past era (2 vs. 1, respectively, P < 0.001). When stratified by 0, 1, 2, and 3 + risk factors present, there was a trend toward lower mortality in the modern group per strata. Univariate and multivariate analysis of the risk factors in the modern group demonstrated that low blood hemoglobin was the only risk factor independently predictive of mortality in the modern group.

CONCLUSIONS

Patients in the modern era group are older and presenting with more predictive risk factors for mortality after rAAA. This has seen an increased rate of rejection for surgery. However, mortality rates following rAAA repair remain unchanged. These results suggest that the previously identified predictive risk factors need to be adjusted.

Medical Therapy Approach for Treating Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a common and deadly problem. The aortic diameter increases in association with a complex remodeling process that includes changes in the structure and content of key proteins, elastin and collagen. As these changes occur, the tissue mechanical properties also change. The natural history of AAA is progressive enlargement to a point of mechanical tissue failure, typically followed by death. Currently, the marker used to predict the risk of impending rupture is the largest transverse diameter. After reaching a diameter threshold of 5.5 cm, the aneurysm is surgically repaired. This criterion does not consider any patient-specific information or the known heterogeneity of the aneurysm that may, in some cases, lead to rupture before the aneurysm reaches the standard intervention threshold. Conversely, in many patients, continued observation beyond this threshold is safe. Although no medical treatment is yet approved, doxycycline has been shown to greatly reduce aortic aneurysm growth in animal models and has been shown to slow growth in several small clinical trials. Although larger prospective randomized trials are needed, one unknown is what effect doxycycline has on the structural integrity of the aortic wall. That is, does slowed aneurysm growth by doxycycline treatments, in fact, prevent rupture, or does the wall continue to weaken and the aneurysm instead ruptures at a smaller diameter? Research has begun to answer these questions before a large clinical trial begins.

Endovascular treatment of abdominal aortic aneurysms

Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR.

Systematic review and meta-analysis of population-based mortality from ruptured abdominal aortic aneurysm

Background

A substantial proportion of patients with a ruptured abdominal aortic aneurysm (rAAA) die outside hospital. The objective of this study was to estimate the total mortality, including prehospital deaths, of patients with rAAA.

Methods

This was a systematic review and meta-analysis following the MOOSE guidelines. The Embase, MEDLINE and Cochrane Library databases were searched. All population-based studies reporting both prehospital and in-hospital mortality in patients with rAAA were included. Studies were assessed for methodological quality and heterogeneity, and pooled estimates of mortality from rAAA were calculated using a random-effects model.

Results

From a total of 3667 studies, 24 retrospective cohort studies, published between 1977 and 2012, met the inclusion criteria. The quality of included studies varied, in particular the method of determining prehospital deaths from rAAA. The estimated pooled total mortality rate was 81 (95 per cent confidence interval 78 to 83) per cent. A decline in mortality was observed over time (P = 0·002); the pooled estimate of total mortality in high-quality studies before 1990 was 86 (83 to 89) per cent, compared with 74 (72 to 77) per cent since 1990. Some 32 (27 to 37) per cent of patients with rAAA died before reaching hospital. The in-hospital non-intervention rate was 40 (33 to 47) per cent, which also declined over the years.

Conclusion

The pooled estimate of total mortality from rAAA is very high, although it has declined over the years. Most patients die outside hospital, and there is no surgical intervention in a considerable number of those who survive to reach hospital.

Explaining the decrease in mortality from abdominal aortic aneurysm rupture

BACKGROUND

A steady rise in mortality from abdominal aortic aneurysm (AAA) was reported in the 1980s and 1990 s, although this is now declining rapidly. Reasons for the recent decline in mortality from AAA rupture are investigated here.

METHODS

Routine statistics for mortality, hospital admissions and procedures in England and Wales were investigated. All data were age-standardized. Trends in smoking, hypertension and treatment for hypercholesterolaemia (statins), together with regression coefficients for mortality, were available from public sources for those aged at least 65 years. Deaths from ruptured AAA avoided in this age group were estimated by using the IMPACT equation: deaths avoided = (deaths in index year) × (risk factor decline) × β-coefficient.

RESULTS

From 1997, deaths from ruptured AAA have decreased sharply, almost twofold in men. Hospital admissions for elective AAA repair have increased modestly (from 40 to 45 per 100,000 population), attributable entirely to more procedures in those aged 75 years and over (P < 0.001). Admissions for ruptured AAA have declined from 18.6 to 13.5 per 100,000 population, across all ages, with the proportion offered and surviving emergency repair unchanged. From 1997, mortality from ruptured aneurysm in those aged at least 65 years has fallen from 65.9 to 44.6 per 100,000 population. An estimated 8-11 deaths per 100,000 population were avoided by a reduced prevalence of smoking and a similar number from an increase in the number of elective AAA repairs. Estimates for the effects of blood pressure and lipid control are uncertain.

CONCLUSION

The reduction in incidence of ruptured AAA since 1997 is attributable largely to changes in smoking prevalence and increases in elective AAA repair in those aged 75 years and over.

Outcome after open repair of ruptured abdominal aortic aneurysm in patients>80 years old: a systematic review and meta-analysis

BACKGROUND

The role of open repair in the management of ruptured abdominal aortic aneurysm (RAAA) in patients>80 years old is questioned by the perceived high operative risk of these patients. This issue has been investigated in the present meta-analysis of observational studies.

METHODS

Studies on open repair of RAAA in patients>80 years old were identified in July 2010. The immediate and intermediate results were expressed as pooled proportions with 95% confidence interval (95% CI). Linear regression and meta-regression were performed to evaluate the impact of variables on the immediate postoperative mortality.

RESULTS

Pooled analysis of 29 studies showed that the risk of immediate postoperative mortality in patients>80 years old was significantly higher than in younger patients (risk ratio 1.440, 95%CI 1.365-1.519, I2 36.8%, P=0.002; risk difference 19.4%, 95% CI 16.4-22.4%, I2 38.8%, P=0.019). Pooled analysis of 36 studies showed an immediate postoperative mortality rate of 59.2% (95% CI 55.7-62.5, I2 35.62). Immediate postoperative mortality in patients<80 years old positively correlated with that of patients>80 years old (rho: 0.686, P<0.0001). Intermediate survival data of 111 operative survivors were available from six studies, and their pooled survival rates at 1-, 2-, and 3-year were 82.4, 75.6, and 68.7%, respectively.

CONCLUSIONS

Immediate and intermediate survival rates of patients>80 years old after open repair of RAAA are acceptable. These findings suggest a more confident approach toward emergency repair of RAAA in the very elderly.

Open repair of ruptured abdominal aortic aneurysm in patients aged 80 years and older

Background

Open repair of ruptured abdominal aortic aneurysm (RAAA) in patients aged 80 years and older may be questioned owing to the patients' high operative risk and short life expectancy.

Methods

Data on patients aged at least 80 years, admitted for RAAA at four Finnish university hospitals, were collected and analysed retrospectively.

Results

Three hundred and ten consecutive patients aged 80 years and older with RAAA reached hospital alive; 200 (64·5 per cent) underwent open repair. The number of open repairs increased during the last 5 years (49·0 per cent of the whole series), with no significant increase in the number of patients treated conservatively. The overall in-hospital mortality rate was 72·9 per cent. The operative mortality rate was 59·0 per cent and decreased from 66 to 52 per cent during the last 5 years (P = 0·050). On multivariable analysis, shock was the only independent predictor of immediate postoperative death (odds ratio 4·97, 95 per cent confidence interval 2·09 to 7·94; P &lt; 0·001). Classification and regression tree analysis showed that preoperative haemoglobin level and presence of shock were predictive of immediate postoperative death; 19 (95 per cent) of 20 patients with shock and a haemoglobin level below 68 g/l died immediately after surgery. Among the 82 survivors of surgery, survival rates at 1, 3 and 5 years were 90, 68 and 45 per cent respectively. These values were not significantly different from those of the age-, sex- and year-matched general population (P = 0·885).

Conclusion

Survival after open repair of RAAA among patients aged 80 years and older is sufficient to justify the procedure, particularly in patients in a stable haemodynamic condition.

Trends in incidence and mortality from abdominal aortic aneurysm in New Zealand

BACKGROUND

This study examined trends in abdominal aortic aneurysm (AAA) incidence and mortality in New Zealand (NZ) and compared these with mortality rates from England and Wales.

METHODS

Cause-specific death data were obtained from the NZ Ministry of Health, UK Office for National Statistics and National Archives (for England and Wales). The NZ National Minimum Data Set provided hospital discharge data from July 1994 to June 2009.

RESULTS

In 2005-2007 the age-standardized AAA mortality rate for men was 33·3 per cent less in NZ than in England and Wales (5·21 versus 7·81 per 100 000), whereas for women it was 9·8 per cent less (2·12 versus 2·35 per 100 000). Standardized mortality rates in NZ fell by 53·0 per cent for men and 34·1 per cent for women from 1991 to 2007. Between 1991-1992 and 2005-2007 the probability of a 65-year-old dying from an AAA fell by 28·2 per cent (from 1·872 to 1·344 per cent) in men, and by 6·3 per cent (from 0·837 to 0·784 per cent) in women. New AAA admission and hospital death rates in NZ peaked in 1999 for men, and in 2001 for women, and have since declined sharply. Hospital mortality ratios have also fallen, except for women with a ruptured aneurysm.

CONCLUSION

The burden of AAA disease has been falling since at least 1991 in NZ, and since 1995 in England and Wales. Although survival appears to be improving, most of the reduction is due to lower disease incidence.

Outcome from abdominal aortic aneurysms in Scotland, 1991-2006

BACKGROUND

This study assessed the impact of sex, presentation and treatment on outcome from abdominal aortic aneurysm (AAA) in Scotland.

METHODS

All patients admitted from January 1991 to December 2006 with a primary diagnosis of AAA were identified. Patients were stratified by age, sex, admission diagnosis (ruptured versus intact) and procedure performed (endovascular versus open repair). Multivariable logistic regression analysis was used to determine predictors of mortality.

RESULTS

Some 9779 men and 2927 women were admitted with a principal diagnosis of AAA. Women were significantly older than men (median (range) age 75 (35-97) versus 71 (17-96) years; P < 0.001). A higher proportion of women presented with a ruptured AAA (29.5 versus 27.5 per cent; P = 0.043). Age (odds ratio (OR) 2.52 (95 per cent confidence interval 2.36 to 2.74); P < 0.001), female sex (OR 1.63 (1.48 to 1.78); P < 0.001) and admission diagnosis (OR 10.49 (9.53 to 11.54); P < 0.001) were independent predictors of early death, whereas endovascular repair predicted survival (OR 0.67 (0.58 to 0.76); P < 0.001).

CONCLUSION

Women presenting with an AAA were older and more likely to be admitted with a ruptured aneurysm. Female sex was an independent risk factor for death from AAA.

Elective surgery for aortic abdominal aneurysm: comparison of English outcomes with those elsewhere

INTRODUCTION

The aim of this study was to quantify mortality after elective repair of abdominal aortic aneurysm (AAA) in England, and to compare English case fatality rates (CFRs) with those reported in the literature.

PATIENTS AND METHODS

English Hospital Episode Statistics (HES) for the financial years 1998/9 to 2001/2, linked to death data, were analysed. A systematic literature search was undertaken to identify studies reporting CFRs after elective AAA surgery. The CFR in England was compared with these studies by using confidence intervals on the CFRs and funnel plot techniques.

RESULTS

In the English study, elective repair of AAA was performed on 11,338 patients of whom 771 died within 30 days after surgery (6.8%). The literature search found 66 studies: 34 reported mortality rates that were within the 99% confidence limits of the English rates, 31 below, and one study above.

DISCUSSION

The CFR after elective surgical repair in England within 30 days of operation (6.8%) was higher than expected from the literature. Differences between England and other countries in quality of care is one possible explanation for the findings, but other explanations are possible and are discussed.

Current trends in the management of small abdominal aortic aneurysms

Over the past decade, there have been revolutionary changes in the diagnosis and treatment of abdominal aortic aneurysms. Minimally invasive endovascular technologies have decreased length of stay and, more importantly, improved at least the early outcomes compared with conventional open surgical therapy. Several large, randomized, prospective trials have re-evaluated the optimal size to treat abdominal aortic aneurysms. The guidelines and conclusions from these studies, the UK Small Aneurysm Trial and The Veterans Affairs Administration aneurysm Detection And Management Trial recommend intervening on aortic aneurysms when they reach 5.5 cm in transverse diameter. However, these studies do not bear direct relevance to contemporary management of aneurysms with endovascular techniques. Clinical trials are currently underway to assess the optimal size for treating abdominal aortic aneurysms with endovascular stent grafts.

The effect of locational disadvantage on hospital utilisation and outcomes in Western Australia

This study analyses the effect of location of residence on hospital utilisation and outcomes using geocoded hospital morbidity and mortality data for the Western Australian population from 1994 to 1999. Compared to highly accessible areas, the overall hospital admission rate ratio was 2.27 (95% CI 2.19-2.36) for those in moderately accessible areas and 2.35 (95% CI 2.23-2.47) for those in remote areas. The corresponding ratios for total length of stay were 1.19 (95% CI 1.17-1.20) and 1.25 (95% CI 1.23-1.27) and the hazard ratios for risk of readmission at 30 days were 1.06 (95% CI 1.04-1.07) and 1.17 (95% CI 1.15-1.19). This study represents an important advance in describing the effects of remoteness on health service utilisation and outcomes.

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.

Cost-effectiveness of different screening strategies for abdominal aortic aneurysm

OBJECTIVE

The primary objective of this study was to develop a simulation model to assess the cost-effectiveness of different screening strategies for abdominal aortic aneurysms (AAAs) in men.

METHODS

A systematic review of the literature was conducted for different screening strategies in terms of age (60, 65, or 70 years) and risk profiles (all men or specific high-risk groups) of the screened population, and rescreening after 5 or 10 years. These data were analyzed in a Markov simulation cohort model.

RESULTS

The cost per life year gained for different screening strategies ranged from US 8,309 dollars to US 14,084 dollars and was estimated at US 10,474 dollars when 65-year-old men were screened once. Screening 60-year-old men was equally cost-effective, with the advantage of more life years gained. We demonstrated a trade-off between high prevalence of AAA and lower life expectancy, eliminating the expected benefits of screening high-risk groups such as smokers (US 10,695 dollars) or cardiovascular patients (US 10,392 dollars). Assuming general population utility resulted in a cost per quality-adjusted life year (QALY) gained of US 13,900 dollars, whereas a hypothetical 5% reduction in utility among men with a screening-detected AAA raised the cost per QALY gained to US 75,100 dollars.

CONCLUSION

This Markov model, which was based on a systematic review of the literature, supplied information on the estimated cost-effectiveness of different screening strategies. Screening men for AAA may be cost-effective in the long-term. Different screening strategies and quality-of-life effects related to screening for AAA need to be evaluated in future clinical studies.

Indications for operative management of abdominal aortic aneurysms

The increasing incidence of abdominal aortic aneurysms, along with the more frequent use of screening techniques, has resulted in greater numbers of patients with small abdominal aortic aneurysms. The questions of frequency of surveillance and timing of intervention are the two most controversial issues faced by surgeons dealing with this condition. Most management decisions are based on the size of the aneurysm but other factors must also be considered. This review makes recommendations on the management of small abdominal aortic aneurysms according to the current available evidence.

Impact of compulsory community treatment on admission rates: survival analysis using linked mental health and offender databases

BACKGROUND

There is controversy as to whether compulsory community treatment for psychiatric patients reduces hospital admission rates.

AIMS

To examine whether community treatment orders (CTOs) reduce admission rates, using a two-stage design of matching and multivariate analyses to take into account socio-demographic factors, clinical factors, case complexity and previous psychiatric and forensic history.

METHOD

Survival analysis of CTO cases and controls from three linked Western Australian databases of health service use, involuntary treatment and forensic history. We used two control groups: one matched on demographic characteristics, diagnosis, past psychiatric history and treatment setting, and consecutive controls matched on date of discharge from in-patient care.

RESULTS

We matched 265 CTO cases with 265 matched controls and 224 consecutive controls (total n=754). The CTO group had a significantly higher readmission rate: 72% v. 65% and 59% for the matched and consecutive controls (log-rank chi(2)=4.7, P=0.03). CTO placement, aboriginal ethnicity, younger age, personality disorder and previous health service use were associated with increased admission rates.

CONCLUSIONS

Community treatment orders alone do not reduce admissions.

Persistent increase in the incidence of abdominal aortic aneurysm in Scotland, 1981–2000

Background

In the 1970s and 1980s, mortality and morbidity rates for abdominal aortic aneurysm (AAA) increased throughout the developed world. As AAAs are associated with similar risk factors to other cardiovascular diseases that have recently decreased in incidence, the incidence of AAA should show a similar declining trend.

Methods

Routinely collected data were obtained on all primary diagnoses of aortic aneurysm resulting in death or hospital discharge in Scotland between 1981 and 2000. Trends in the data were analysed according to sex and age, aneurysm site and type of hospital admission.

Results

Between 1981 and 2000, 42·3 per cent of the 10 822 deaths from aortic aneurysm in Scotland were attributed to the abdominal aorta. Age-adjusted mortality rates for AAA increased 2·6-fold from 2·62 deaths per 100 000 in 1981 to 6·82 per 100 000 in 2000. Hospital admissions for AAA also rose threefold, with increases in both elective admissions (from 3·05 to 7·80 per 100 000) and emergency admissions (from 7·44 to 11·23 per 100 000).

Conclusion

The incidence of AAA has increased over the past 20 years in Scotland. This is unlikely to be due simply to changes in detection and diagnosis, data inaccuracies, coding or ageing of the population. The incidence of both elective and emergency admission for AAA increased, suggesting that a genuine and persistent rise in the incidence of AAA has probably occurred.

Initial experience of abdominal aortic aneurysm repairs in Borneo

BACKGROUND

Abdominal aortic aneurysms (AAA) repairs are routine operations with low mortality in the developed world. There are few studies on the operative management of AAA in the Asian population.This study reports the initial results from a unit with no previous experience in this surgery by a single surgeon on completion of training.

METHODS

All patients with AAA repair from a prospective database between 1996 and 1999 in the south-east Asian state of Sarawak in Borneo Island were analyzed. Three groups were identified on presentation according to clinical urgency of surgery. Elective surgery was offered to all good risk patients with AAA of >or= 5 cm. All symptomatic patients were offered surgery unless contraindicated medically.

RESULTS

AAA repairs were performed in 69 patients: 32 (46%)had elective repairs of asymptomatic AAA; 20 (29%) had urgent surgery for symptomatic non-ruptured AAA; and 17 (25%)had surgery for ruptured AAA. The mortality rate for elective surgery was 6%; the two deaths occurred early in the series with the subsequent 25 repairs recorded no further mortality. The mortality rates for the urgent, symptomatic non-ruptured AAA repair and ruptured AAA repair were 20% and 35%, respectively. Cardiac and respiratory complications were the main morbidities.Sixty-three patients seen during this period had no surgery; three presented and died of ruptured AAA, 34 had AAA of <or= 5 c min diameter, and 26 with AAA of >or= 5 cm diameter had either no consent for surgery or serious medical contraindications.

CONCLUSION

This study showed that AAA can be repaired safely by highly motivated and adequately trained surgeons in a hospital with little previous experience.

Outcome of endovascular abdominal aortic aneurysm repair in patients with conditions considered unfit for an open procedure: a report on the EUROSTAR experience

OBJECTIVE

Endovascular abdominal aortic aneurysm repair (EAR) can be performed in patients whose conditions were previously considered unfit for conventional treatment of the aneurysm. However, because the life span in this category of patients often is limited because of serious comorbidity, the efficacy of EAR in prolonging life expectancy remains uncertain. This study involves the evaluation of preoperative risk classification and an assessment of the outcome of interventions.

METHODS

The data of 3075 patients, who underwent operation in 101 European institutions that collaborated in the EUROSTAR Registry, were assessed. Only the patients who had been prospectively enrolled in the registry were used for this analysis. Patient characteristics, operative risk factors, procedural details, and types of devices were correlated with preoperative estimates of operative risk, early and late mortality, complications, and primary and secondary outcome success rates. In addition, the intermediate-term survival rates in patients with unfit conditions with EAR (observed series) and with conservative approaches of the aneurysms (rupture rates as derived from the literature) were compared in a mathematical model.

RESULTS

Of the overall study group, 2525 patients were at "normal" risk for a surgical procedure (group A), 399 patients had conditions that were considered unfit for open surgery (group B), and 151 patients had conditions that were unfit for general anesthesia (group C). Both unfit categories had significantly more comorbid factors and larger aneurysms than did the patients in good medical condition. Differences were observed in comorbidities between the two high-risk categories, groups B and C. Factors that influenced the abdominal approach (previous laparotomies, hostile abdomen, and obesity) and local anatomic factors (eg, retroperitoneal fibrosis, inflammatory aneurysm, dissections, and enterostomy) were present in 19% of the patients with conditions that were unfit for open surgery and in only 1% of the category unfit for anesthesia. In contrast, severe pulmonary disease was present in 33% of the patients with conditions that were unfit for anesthesia as opposed to 11% of the patients with conditions that were unfit for open surgery. The early and late mortality rates were significantly higher in the unfit categories (groups B and C). Life table results showed a 3-year survival rate of 83% in patients at normal operative risk and of 68% in patients with unfit conditions (P =.0001). An independent correlation with late death was shown for the clinical classification into high-risk groups B and C, pulmonary disease, team experience of less than 60 procedures, and the diameter of the aneurysm. In groups B and C, aneurysms smaller than 6.0 cm were associated with a 2-year survival rate of 80% and larger aneurysms with a rate of 68% (P =.02). This difference was caused by an increased non-aneurysm-related mortality rate in the group with aneurysms of more than 6 cm. The mathematical model showed an advantage of EAR with regard to the reduction of the death rate in patients with unfit conditions as compared with no intervention after 1 year. The advantage of EAR was observed in patients with AAAs between 5 and 6 cm and with larger aneurysms.

CONCLUSION

Early and late mortality rates were increased in patients with the preoperative clinical diagnosis "unfit for open surgery and general anesthesia" as compared with patients at "normal" operative risk. EAR appeared of potential benefit in patients with unfit conditions, regardless of the aneurysm diameter. The life expectancy of patients at high risk who are considered for EAR should be longer than 1 year before any realistic gain in life span can be anticipated.

Initial results of ultrasound screening for aneurysm of the abdominal aorta in Western Australia: relevance for endoluminal treatment of aneurysm disease

BACKGROUND

Increased life expectancy in men during the last thirty years is largely due to the decrease in mortality from cardiovascular disease in the age group 29--69 yr. This change has resulted in a change in the disease profile of the population with conditions such as aneurysm of the abdominal aorta (AAA) becoming more prevalent. The advent of endoluminal treatment for AAA has encouraged prophylactic intervention and fueled the argument to screen for the disease. The feasibility of inserting an endoluminal graft is dependent on the morphology and growth characteristics of the aneurysm. This study used data from a randomized controlled trial of ultrasound screening for AAA in men aged 65--83 yr in Western Australia for the purpose of determining the norms of the living anatomy in the pressurized infrarenal aorta.

AIMS

To examine (1) the diameters of the infra-renal aorta in aneurysmal and non-aneurysmal cases, (2) the implications for treatment modalities, with particular reference to endoluminal grafting, which is most dependent on normal and aneurysmal morphology, and (3) any evidence to support the notion that northern Europeans are predisposed to aneurysmal disease.

METHODS

Using ultrasound, a randomized control trial was established in Western Australia to assess the value of a screening program in males aged 65--83 yr. The infra-renal aorta was defined as aneurysmal if the maximum diameter was 30 mm or more. Aortic diameter was modelled both as a continuous (in mm) and as a binary outcome variable, for those men who had an infra-renal diameter of 30 mm or more. ANOVA and linear regression were used for modelling aortic diameter as a continuum, while chi-square analysis and logistic regression were used in comparing men with and without the diagnosis of AAA.

FINDINGS

By December 1998, of 19,583 men had been invited to undergo ultrasound screening for AAA, 12,203 accepted the invitation (corrected response fraction 70.8%). The prevalence of AAA increased with age from 4.8% at 65 yr to 10.8% at 80 yr (chi(2)=77.9, df=3, P<0.001). The median (IQR) diameter for the non-aneurysmal group was 21.4 mm (3.3 mm) and there was an increase (chi(2)=76.0, df=1, P<0.001) in the diameter of the infra-renal aorta with age. Since 27 mm is the 95th centile for the non-aneurysmal infra-renal aorta, a diameter of 30 mm or more is justified as defining an aneurysm. The risk of AAA was higher in men of Australian (OR=1.0) and northern European origin (OR=1.0, 95%CL: 0.9, 1.2) compared with those of Mediterranean origin (OR=0.5, 95%CL: 0.4, 0.7).

CONCLUSION

Although screening has not yet been shown to reduce mortality from AAA, these population-based data assist the understanding of aneurysmal disease and the further development and use of endoluminal grafts for this condition.

Long-term relative survival following surgery for abdominal aortic aneurysm: a review

BACKGROUND

The literature reporting the long-term survival following surgery for abdominal aortic aneurysm (AAA) tends to be confusing. As a result, many clinicians looking after patients with AAA may be uncertain about the five-year survival of a given patient. This is in marked contrast to the situation for patients with malignant disease. With the current interest in population screening and endoluminal stenting for AAA, an understanding of long-term survival is increasingly important.

METHODS

Thirty two publications in the English language over the last 20 years, containing data pertaining to five-year survival following routine elective surgery for AAA in unselected patients, were identified using Medline searches.

RESULTS AND CONCLUSIONS

A range of important methodological differences were noted. The mean five-year crude survival was about 70% while the expected survival of a matched population was close to 80%. Survival was further reduced by about 10% in cases with significant coronary heart disease. Age alone is not a predictor of long-term relative survival with octogenarians who survive beyond 30 days surviving longer than an age-matched population.

Mortality from aortic aneurysms in Australia, 1968 to 1997

OBJECTIVES

Describe trends in mortality for aortic aneurysms in Australia for the period 1968 to 1997.

DESIGN

Descriptive study of time trends in mortality.

MAIN OUTCOME MEASURE

Age-sex-standardised mortality rates with statistical analysis of trends using negative-binomial regression.

RESULTS

While overall mortality rates for aortic aneurysms remained relatively constant for the period 1968 to 1992 in Australia, there has been a small but significant reduction in the rate from then until the end of the series in 1997. When different types of aneurysms are considered, there have been increases in the rates associated with abdominal aortic aneurysms and thoracic aortic aneurysms, while those for dissecting aortic aneurysms have declined. Most significantly, mortality rates for unspecified aortic aneurysms have declined.

CONCLUSION

Aortic aneurysm mortality has declined in Australia in recent years. The reasons for this are unclear. While there have been increases associated with abdominal aortic aneurysm mortality, this is likely to be a result of more precise coding of death rather than any real increase in mortality.

Life-style factors and risk for abdominal aortic aneurysm in a cohort of Finnish male smokers

Prospective studies evaluating risk factors for abdominal aortic aneurysm are few. We studied the association of life-style factors with risk for abdominal aortic aneurysm among 29,133 male smokers 50-69 years of age, participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. During a mean follow-up of 5.8 years, 181 were diagnosed with ruptured abdominal aortic aneurysm or nonruptured abdominal aortic aneurysm plus aneurysmectomy. Risk for abdominal aortic aneurysm was positively associated with age [relative risk (RR) = 4.56, 95% confidence interval (CI) = 2.42-8.61 for > 65 vs < or = 55 years], smoking years (RR = 2.25, 95% CI = 1.33-3.81 for > 40 vs < or = 32 years), systolic blood pressure (RR = 1.92, 95% CI = 1.13-3.25 for > 160 vs < or = 130 mmHg), diastolic blood pressure (RR = 1.80, 95% CI = 1.05-3.08 for > 100 vs < or = 85 mmHg), and serum total cholesterol (RR = 1.85, 95% CI = 1.09-3.12 for > 6.5 vs < or = 5.0 mmol/liter). High-density lipoprotein cholesterol showed a strong inverse association with risk for aortic aneurysm (RR = 0.16, 95% CI = 0.08-0.32 for > 1.5 vs < or = 0.9 mmol/liter). High energy intake was associated with lower risk for aortic aneurysm (RR = 0.59, 95% CI = 0.38-0.94 for the highest quartile vs the lowest), whereas no associations with nutrients were evident. We conclude that classical risk factors for atherosclerotic diseases seem to be important in pathogenesis of large abdominal aortic aneurysms.

Screening for abdominal aortic aneurysm: lessons from a population-based study

OBJECTIVES

To test the acceptability of screening and to identify modifiable risk factors for abdominal aortic aneurysm (AAA) in men.

DESIGN

A trial of ultrasound screening for AAA in a population-based random sample of men aged 65-83 years, and a cross-sectional case-control comparison of men in the same sample.

PARTICIPANTS

12,203 men who had an ultrasound examination of their abdominal aorta, and completed a questionnaire covering demographic, behavioural and medical factors.

MAIN OUTCOME MEASURES

Prevalence of AAA, and independent associations of AAA with demographic, medical and lifestyle factors.

RESULTS

Invitations to screening produced a corrected response of 70.5%. The prevalence of AAAs (> 30 mm) rose from 4.8% in men aged 65-69 years to 10.8% in those aged 80-83 years. The overall prevalence of large (> 50 mm) aneurysms was 0.69%. In a multivariate logistic model Mediterranean-born men had a 40% lower risk of AAA (> 30 mm) compared with men born in Australia (odds ratio [OR], 0.6; 95% CI, 0.4-0.8), while ex-smokers had a significantly increased risk of AAA (OR, 2.3; 95% CI, 1.9-2.8), and current smokers had even higher risks. AAA was significantly associated with established coronary and peripheral arterial disease and a waist:hip ratio greater than 0.9; men who regularly undertook vigorous exercise had a lower risk (OR, 0.8; 95% CI, 0.7-1.0).

CONCLUSION

Ultrasound screening for AAA is acceptable to men in the likely target population. AAA shares some but not all of the risk factors for occlusive vascular disease, but the scope for primary prevention of AAA in later life is limited.

Influence of gender on outcome from ruptured abdominal aortic aneurysm

BACKGROUND

The aim of the present study was to compare outcomes following ruptured abdominal aortic aneurysm (AAA) in men and women.

METHODS

Overall mortality from ruptured AAA was compared in men and women using the Western Australia Health Services Research Database. The linked chains of de-identified hospital morbidity and death records were selected using the ICD-9-CM (International Classification of Diseases - Clinical Modification) diagnostic and procedure codes pertaining to AAA. Cases were divided into three groups for analysis: patients who died without admission to hospital, those admitted to hospital with a ruptured AAA but who did not undergo operation, and patients who underwent operation for ruptured AAA.

RESULTS

Ruptured AAA occurred in 648 men and 225 women over the age of 55 years during the decade 1985-1994. Only 50 per cent of women, compared with 59 per cent of men, were admitted to hospital. Of those admitted to hospital only 37 per cent of women underwent operation, compared with 63 per cent of men. The overall mortality rate from ruptured AAA was 90 per cent in women and 76 per cent in men (chi2 = 50.34, 1 d.f., P < 0.0001). Although women were, on average, 6 years older than men, this unfavourable pattern occurred across all age groups.

CONCLUSION

Women with a ruptured AAA are more likely to die than men. More research is required to identify the causes of this sex difference.

Community and hospital outcome from ruptured abdominal aortic aneurysm within the catchment area of a regional vascular surgical service

OBJECTIVE

The objective of this study was to examine patterns of referral, management, and outcome of patients with ruptured abdominal aortic aneurysm (RAAA) within the catchment area of this regional vascular unit (RVU).

METHODS

Referral, management, and outcome data regarding 972 consecutive patients admitted to the hospital or certified deceased in the community because of RAAA between January 1, 1989, and December 31, 1995, were retrieved from prospectively gathered computerized national and local databases.

RESULTS

Of 381 (39.2%) patients admitted to this unit, 316 (82.9%) underwent surgery, and of those, 188 (59.5%) survived. There was no significant difference in overall mortality between patients who were admitted directly to this unit (152 of 310, 49%) and those who were transferred from elsewhere (41 of 71, 58%). Surgical patients traveled significantly farther to the RVU than nonsurgical patients (P <.001), but there was no significant difference in traveling distance between surgical patients who survived and those who did not. Of 372 (38%) patients who were admitted to other units and not transferred, 24 (6.4%) underwent surgery and 14 (3.8%) survived. Of 972 patients, the overall community mortality from RAAA was 770 (79%).

CONCLUSION

Transferring patients from outlying units did not appear to prejudice operative outcome in this RVU. However, less than half of all RAAA patients were transferred, and only a small minority of those not transferred underwent surgery. Although the overall community mortality from RAAA was similar to that reported in earlier studies from other regions and countries where centralization has not occurred, centralization of vascular surgical services may be associated with an inappropriately low operation and survival rate for those patients who are not transferred to the regional center. The effect of centralization on the community outcome of emergent vascular surgical conditions requires further investigation.

Long term relative survival after surgery for abdominal aortic aneurysm in western Australia: population based study

OBJECTIVE

To determine the long term relative survival of all patients who had surgery for abdominal aortic aneurysm in Western Australia during 1985-94.

DESIGN

Population based study.

SETTING

Western Australia.

SUBJECTS

All patients who had had surgery for abdominal aortic aneurysm in Western Australia during 1985-94.

MAIN OUTCOME MEASURES

Morbidity and mortality data of patients admitted and surgically treated for abdominal aortic aneurysm in Western Australia during 1985-94. Elective, ruptured, and acute non-ruptured cases were analysed separately. Independent analyses for sex and patients aged 80 years or more were also undertaken. Postoperative (>30 days) relative survival was assessed against age and sex matched controls.

RESULTS

Overall, 1475 (1257 men, 218 women) cases were identified. The crude five year survival after elective surgery, including deaths within 30 days of surgery, was 79% for both men and women. When compared with a matched population the five year relative survival after elective surgery was 94.9% (95% confidence interval 89.9% to 99.9%) for men but only 88.0% (76.3% to 99.7%) for women. The five year relative survival of those aged 80 years and over was good: 116.6% (89.1% to 144.0%) compared with 92.4% (87.7% to 97.0%) for those under 80 years of age (men and women combined). Cardiovascular disease caused 57.8% of the 341 deaths after 30 days.

CONCLUSION

In a condition such as abdominal aortic aneurysm, which occurs in elderly patients, relative survival is more clinically meaningful than crude survival. The five year relative survival in cases of elective and ruptured abdominal aortic aneurysm was better in men than in women. This is probably because of greater comorbidity in women with abdominal aortic aneurysm and this deserves more attention in the future. The long term survival outcome in octogenarians supports surgery in selected cases.