A systematic review and case presentation: Giant abdominal aortic aneurysm

OBJECTIVE

An abdominal aortic aneurysm is considered giant when its transverse diameter is greater than 10-13 cm in diameter. A giant abdominal aortic aneurysm is rare but with a significant risk of rupture if it is not diagnosed or left untreated.

METHOD

The authors have performed a systematic review of the evidence that has looked into the clinical presentations, and management methods employed and have presented a 14 cm giant abdominal aortic aneurysm patient.

RESULTS

The systematic review has been based on level-IV evidence due to the rarity of the condition. The final analysis included 61 relevant reported cases. The mean age was 72.4 years, the male to female ratio was 52: 8, and the average size of a giant abdominal aortic aneurysm was 14.7 cm. These were mostly infra renal (72.58%). Rupture of these aneurysms was found in 23 (37.1%) patients, and was treated by laparotomy in 51 (82.25%) cases. There were 11 (17.74%) mortalities.

CONCLUSION

The size of an abdominal aortic aneurysm is known to be the biggest factor in the rupture of an aneurysm. The reason abdominal aortic aneurysms can reach such size without rupturing is unclear but needs further exploring. Early diagnosis with effective screening programmes is essential to diagnose in a timely manner to avoid life-threatening consequences.

Survival of Ruptured Abdominal Aortic Aneurysms in the West of Ireland: Do Prognostic Indicators of Outcome Exist?

Ruptured abdominal aortic aneurysm (RAAA) is a demanding vascular surgical problem and the cause of significant morbidity and mortality. The aim of this study was to identify prognostic factors that influence outcome. Over 6 years, 42 ruptured abdominal aortic aneurysms were operated on with a mean diameter of 7.2 cm. RAAA was defined as free intraperitoneal rupture. Data were collected retrospectively from hospital medical records. The male:female ratio was 8:1 and the mean age was 74 years (range 55–89). Fifteen were in hypovolemic shock and 27 patients were clinically stable. The perioperative mortality rate for the 15 shocked patients was 60% (9 patients) and the 1-year cumulative survival rate was 33%. The perioperative mortality rate for the 27 clinically stable patients was 40% (11 patients) and the 1-year cumulative survival rate was 56%. Survival curves were constructed for these groups to compare male versus female, age =70 versus age <70, shocked versus stable, and preoperative hemoglobin (Hb) =10 vs >10. No patient with preoperative cardiac arrest survived more than 24 hours. With VassarStats, the confidence interval for age, gender, hemodynamic status, and preoperative Hb were calculated. The standard weighted mean analysis by ANOVA gave a p value of <0.001. The overall 30-day mortality rate was 47% (20 of 42) and the 1-year mortality rate was 52% (22 of 42). Male patients over 70 years with RAAA in hypovolemic shock with low Hb have a higher 30-day mortality rate and few survive more than 1 year. The study suggests that each of these 4 parameters separately was not a strong prognostic indicator. Collectively, however, they strongly influence the prognosis of patients with RAAA. These findings strengthen the case for selective treatment for RAAA.

Screening for aortic aneurysms in patients with coronary artery disease: should it be done?

Aneurysmal dilation of the aorta is a clinically silent disease that often presents first with a catastrophic event. As a result, several clinician societies and organizations have recommended screening to detect aneurysms before they rupture. Although screening may reduce mortality, the implementation of screening has been poor. Cardiologists are uniquely positioned to improve this gap as they handle patients with typical risk factors for aneurysmal diseases of the aorta and can endorse and implement screening in a high-risk population. The following article attempts to concisely give a navigational tool to the cardiovascular specialist for her/his role in the diagnosis and management of thoracic and abdominal aortic aneurysms, citing evidence as well as stating opinions on how to improve outcomes in this unique patient population.

Endovascular versus open repair of ruptured abdominal aortic aneurysms

Although major improvement has occurred to make elective repair of abdominal aortic aneurysms a safe procedure, the incidence of ruptured abdominal aortic aneurysms and mortality rates are still disappointing. Endovascular abdominal aortic aneurysm repair has produced quantum changes in aneurysm treatment. The successful application of the endovascular approach for the treatment of abdominal aortic aneurysms in the elective setting has prompted a strong interest regarding its possible use in dealing with the long-standing challenge of a ruptured abdominal aortic aneurysm. Since the first report, several centers have reported results and a wide spectrum of opinion regarding its application, with special consideration to logistical and practical barriers for appropriate utilization. The purpose of this article is to review all the available literature on the endovascular repair of ruptured abdominal aortic aneurysms and to analyze the most recent trends in their management, with special consideration given to comparing results of conventional and endovascular approaches.

On the prediction of monocyte deposition in abdominal aortic aneurysms using computational fluid dynamics

In abdominal aortic aneurysm disease, the aortic wall is exposed to intense biological activity involving inflammation and matrix metalloproteinase–mediated degradation of the extracellular matrix. These processes are orchestrated by monocytes and rather than affecting the aorta uniformly, damage and weaken focal areas of the wall leaving it vulnerable to rupture. This study attempts to model numerically the deposition of monocytes using large eddy simulation, discrete phase modelling and near-wall particle residence time. The model was first applied to idealised aneurysms and then to three patient-specific lumen geometries using three-component inlet velocities derived from phase-contrast magnetic resonance imaging. The use of a novel, variable wall shear stress-limiter based on previous experimental data significantly improved the results. Simulations identified a critical diameter (1.8 times the inlet diameter) beyond which significant monocyte deposition is expected to occur. Monocyte adhesion occurred proximally in smaller abdominal aortic aneurysms and distally as the sac expands. The near-wall particle residence time observed in each of the patient-specific models was markedly different. Discrete hotspots of monocyte residence time were detected, suggesting that the monocyte infiltration responsible for the breakdown of the abdominal aortic aneurysm wall occurs heterogeneously. Peak monocyte residence time was found to increase with aneurysm sac size. Further work addressing certain limitations is needed in a larger cohort to determine clinical significance.

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.

Outcome in patients requiring renal replacement therapy after open surgical repair for ruptured abdominal aortic aneurysm

OBJECTIVE

To determine the relationship between postoperative renal replacement therapy (RRT) and patient survival after open surgical repair (OR) of ruptured abdominal aortic aneurysm (rAAA).

METHODS

A retrospective review of consecutive patients who underwent OR for rAAA repair between January 2002 and July 2008 was performed. Early (<30 days) and late (>30 days) outcomes were assessed.

RESULTS

A total of 94 patients (69 men; median [range] age 73.8 [56-89] years) underwent OR of rAAA (infrarenal = 78, juxtarenal = 15, and suprarenal = 1). In-hospital mortality rate was 40% and mean (range) length of intensive care unit (ICU) stay was 9.3 (0-56) days. A total of 23 (24%) patients required postoperative RRT. In-hospital mortality rate was significantly higher (RRT: 87% (20 of 23) vs no RRT: 18 of 71 (25%), P < .0001) and ICU stay significantly longer (RRT: mean (range) days; 14.8 (1-44) vs no RRT: 7.5 (0-56), P = .04) in the RRT patients. On multivariate analysis, RRT (P = .0053) and/or inotropic support (P = .0033) were independent risk factors for death within 30 days of the index procedure.

CONCLUSIONS

Renal replacement therapy following OR of rAAA is an independent risk factor for mortality.

Prognostic scoring in ruptured abdominal aortic aneurysm: a prospective evaluation

BACKGROUND

Prospective validation of prognostic scoring systems for ruptured abdominal aortic aneurysm (AAA) is lacking. This study assesses the validity of three established risk scores and a new prognostic index.

METHOD

Patients admitted with ruptured AAA during a 26-month period (August 2002-December 2004) were recruited prospectively. The Glasgow Aneurysm Score (GAS), Hardman Index, Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) scores, and the Edinburgh Ruptured Aneurysm Score (ERAS) were recorded and related to outcome.

RESULTS

During the study period, 111 patients were admitted with ruptured AAA. Of these, 84 (76%) underwent attempted operative repair and were included in the study; 37 (44%) died after operation. The GAS, Hardman Index, and the ERAS were statistically related to mortality. However, analysis by receiver-operator characteristic curve revealed the ERAS to have an area under the curve (AUC) of 0.72 (95% confidence interval [CI], 0.61-0.83). The vascular (V)-POSSUM and ruptured AAA (RAAA)-POSSUM models had an AUC of 0.70 (95% CI, 0.59-0.82). The Hardman Index and GAS had an AUC of 0.69 (95% CI, 0.57-0.80) and 0.64 (95% CI, 0.52-0.76), respectively. Although the V-POSSUM equation predicted mortality effectively (P = .086), the RAAA-POSSUM derivative demonstrated a significant lack of fit (P = .009).

CONCLUSION

Prospective validation shows that the Hardman Index, GAS, and V-POSSUM and RAAA-POSSUM scores do not perform well as predictors for death after ruptured AAA. The ERAS accurately stratifies perioperative risk but requires further validation.

Predictors of outcome after abdominal aortic aneurysm rupture: Edinburgh Ruptured Aneurysm Score

BACKGROUND

Many surgeons adopt a selective policy of intervention for a ruptured abdominal aortic aneurysm (AAA). This study aimed to develop an objective method of identifying patients suitable for attempted repair.

METHODS

Consecutive patients selected for attempted repair of ruptured AAA over a 31-month period (January 2000 to July 2002) were entered into an observational study. Altogether, 53 preoperative physiological and biochemical variables were recorded and related to operative outcome.

RESULTS

A total of 105 patients underwent attempted repair of a ruptured AAA. There were 39 (37%) deaths in hospital or within 30 days of operation. On univariate analysis, hemoglobin <9 g/dl (p = 0.038), blood pressure <90 mmHg (p = 0.036), and Glasgow Coma Scale <15 (p = 0.016) were found to be risk factors that predicted death. Of 70 patients with no or one risk factor, 20 (29%) died. Of 30 patients with two factors, 15 (50%) died, and of the five patients with all three factors, four (80%) died. There was a significant association between mortality and cumulative risk factors (p = 0.003).

CONCLUSION

These three risk factors are easily assessed in the emergency setting and might form the basis of a scoring system to inform the outcome of ruptured AAA.

Abdominal Aortic Aneurysm Surgery in a District General Hospital: A 15-Years Experience

The incidence of patients presenting with both ruptured abdominal aortic aneurysm (RAAA) and elective abdominal aortic aneurysm (EAAA) increases with age. The aim of our study was to find out the incidence of RAAA, age and sex groups of patients at risk, and 30-day all-cause perioperative mortality associated with RAAA as well as EAAA repair in a busy district general hospital over a 15-year time period. All patients operated for AAA during 1989-2003, both elective and ruptured, were included in the study. Patients who died in the community from RAAA were also included. The data were collected from the hospital information system, theater logbooks, intensive therapy unit records, postmortem register, and patients' medical notes. We divided the data for RAAA into two groups of 7.5 years each to see if there was any improvement over time in 30-day postoperative mortality. There were 816 cases of AAA, which included 468 RAAAs (57%) and 348 EAAAs (43%). Out of 468 RAAAs, 243 patients had emergency repair, of whom 213 were males. There were 201 patients who had RAAA postmortem (43%). Median age (range) was 73 (54-94) years in males and 77 (52-99) years in females, with a male-to-female ratio of 7:1. The peak incidence of RAAA was over 60 years of age in males and 70 years in females. Incidence of RAAA was 7.3/100,000/year in males and 5/100,000/year in females. For RAAA, 30-day perioperative mortality was 43% (105/243) while overall mortality was 70% (330/468), which includes deaths in the community. There was no improvement in 30-day mortality over time after comparing data for the first 7.5 years (50/115, 43.5%) with those for the second set of 7.5 years (55/128, 43%). There were 348 patients who had EAAA repair over the same period, comprising 282 males, with a male:female ratio of 4.3:1. The 30-day mortality in the elective group was 7.75%. Incidence and mortality of RAAA remain high. A high proportion of patients with AAA remain undiagnosed and die in the community. More lives may be saved if a screening program is started for AAA.

Improvement of Mortality of Ruptured Abdominal Aortic Aneurysm Patients over 12 Years and Its Relationship with Tracheostomy

Cardiopulmonary complication after ruptured abdominal aortic aneurysm (rAAA) repair is an important cause of mortality. Early tracheostomy promotes patient recovery from respiratory morbidities. A policy of routine immediate tracheostomy was adopted in 1999 at our institution. This study investigates the trend of hospital mortality of rAAA patients over 12 years with particular reference to immediate tracheostomy. Consecutive rAAA patients operated during 1993-2004 were divided into two groups (first group, 1993-1998; second group, 1999-2002). Intra- and postoperative care was the same for all patients except that immediate tracheostomy was performed routinely in the second group and only selectively in the first. Hospital mortality of the two groups was examined. Patient characteristics, biochemical parameters, aneurysm feature, operative details, and clinical outcomes of the two groups (excluding 48 hr perioperative mortalities) were compared to identify prognostic factors of hospital mortality. Sixty-three patients were operated during the study period. The overall hospital mortality for the first and second groups was 62.5% (20/32) and 22.6% (7/31) (p=0.001), respectively. Excluding the 48 hr mortalities, 57.1% (12, n=21) of patients in the first group and 85.7% (24, n=28) of those in the second group survived to be discharged from hospital (p=0.048). The pre-, intra-, and postoperative parameters were comparable between the two groups. Immediate tracheostomy was performed for all patients in the second group and only 52.4% (11) in the first group. Male gender, high creatinine level on presentation, postoperation cardiac morbidity, renal failure, and bowel ischemia were found to be associated with a higher mortality. Immediate tracheostomy is a significant factor associated with improved survival. In conclusion, a significant improvement of rAAA patients' in-hospital mortality was achieved during the study period. Tracheostomy performed immediately following rAAA repair is associated with better hospital survival.

Serum lactate and base deficit as predictors of mortality after ruptured abdominal aortic aneurysm repair

OBJECTIVE

Whole body hypoperfusion and lower torso ischaemia-reperfusion contribute to post-operative organ dysfunction in patients undergoing repair of ruptured abdominal aortic aneurysm (AAA). Serum lactate and base deficit are markers of tissue ischaemia and are used to assess the adequacy of resuscitation. This study examines the prognostic value of immediate post-operative levels of serum lactate and base deficit in ruptured AAA.

METHODS

Thirty patients (24 men and 6 women of median age 74, range 51-85, years) who survived to at least 12h after ruptured AAA repair were studied retrospectively. The relationship between immediate post-operative lactate, base deficit and mortality was determined.

RESULTS

Fifteen patients (50%) died, all from organ failure. An elevated lactate (>2.1 mmol/l) and base deficit (<-2 mmol/l) were present in 20 (67%) and 27 (90%) patients, respectively. Lactate (p<0.001) and base deficit (p=0.003) were significantly higher in non-survivors compared with survivors. Lactate (p=0.021) and base deficit levels (p=0.028) were independently significant for predicting mortality and a significant interaction existed between lactate and base deficit levels for predicting mortality (p=0.027). The sensitivity and specificity of lactate > or =4.0 mmol/l was 13 of 15 (87%) and 12 of 15 (80%), respectively, and base deficit < or =-7 mmol/l was 12 of 15 (80%) and 12 of 15 (80%), respectively. The likelihood ratios for a positive result with the defined cut-off values for lactate and base deficit were 4.3 and 4.0, respectively. Lactate > or =4.0 mmol/l and base deficit <or =-7 mmol/l were associated with a 94.5% probability of death while lactate < or =4.0 mmol/l and base deficit > or =-7 mmol/l were associated with a 4% probability of death.

CONCLUSION

These data demonstrate that an immediate post-operative serum lactate > or =4.0 mmol/l and base deficit < or =-7 mmol/l are good predictors of outcome after ruptured AAA repair. The prognostic value of these simple and inexpensive tests require corroboration in a larger prospective study.

Outcome and survival of patients aged 65 years and younger after abdominal aortic aneurysm rupture

Advanced age (> 80 years) confers a survival disadvantage after operative repair of a ruptured abdominal aortic aneurysm (AAA). This study aimed to determine if young age (< or =65 years) confers a survival benefit. Consecutive patients undergoing attempted repair of a ruptured AAA between 1995 and 2001 were included in the study. Demographic, clinical, and operative factors were analyzed together with in-hospital mortality, duration of postoperative hospital stay, and long-term survival. Of 378 patients admitted with a ruptured AAA, 52 (14%) were < or = 65 years of age and 326 (86%) were > 65 years. There were 4 (8%) women in the younger cohort compared to 74 (23%) women in the older group (p = 0.015). Four (8%) patients in the younger group were thought to be unsuitable for surgical repair compared to 77 (24%) patients in the older cohort (p = 0.009). Of the 48 younger patients who underwent attempted operative repair, 22 (46%) died in hospital, compared to 108 (43%) of 249 patients > 65 years (p = 0.753). The median (range) postoperative hospital stay of survivors was 11 days (6-59 days) in the younger cohort and 15 days (6-121 days) in the older group (p = 0.005). Patients < or = 65 years of age undergoing operative repair of ruptured AAA have no survival advantage over older patients. These data support AAA screening for the "at risk" and age-defined population.

Existing Delays Following the Presentation of Ruptured Abdominal Aortic Aneurysm Allow Sufficient Time to Assess Patients for Endovascular Repair

OBJECTIVES

The greatest benefit of endovascular AAA repair (EVAR) may be in the management of rupture (RAAA). However, the detailed anatomical assessment required for EVAR has lead to concerns of surgical delay and death during cross-sectional imaging. In this study, we prospectively assessed patients with RAAA and correlated time of hospital arrival with time of surgery or death to ascertain whether these concerns are justified.

METHODS

All patients presenting with RAAA between October 2000 and December 2002 were included. The hospital arrival time, onset of surgery or time of death, were recorded, as were demographic and physiological parameters.

RESULTS

One hundred consecutive patients were studied, median age 75 years (range 54-94). Seventy-nine patients underwent attempted conventional surgical repair and 21 were palliated. The median delay from arrival to operation was 159 min (range 16-1450 min). Mortality in the surgical group was not affected by the length of delay (p = 1.0) or by CT scanning (p = 0.34). The median time from arrival to death in the non-surgical group was 435 min (15 min-6 days).

CONCLUSIONS

Most patients who present with ruptured AAA experience a significant delay prior to surgery. This study suggests it is safe to assess the majority of RAAA patients for EVAR.

Endovascular repair of a ruptured abdominal aortic aneurysm under local anaesthesia

Abdominal aortic aneurysm (AAA) is a common degenerative condition affecting the elderly population. Rupture carries a high overall mortality. Elective endovascular stent graft repair is well described. We describe a patient with ruptured AAA and co-morbid conditions making him unfit for surgery and general or epidural anaesthesia, who was successfully treated by endovascular stent graft under local anaesthesia.

Coagulopathy and Hyperfibrinolysis in Ruptured Abdominal Aortic Aneurysm Repair

Perioperative hemorrhage is one of the principal causes of death in patients with ruptured abdominal aortic aneurysm (AAA). This study examines perioperative coagulation and fibrinolysis in patients undergoing ruptured AAA repair complicated by coagulopathy. Eight patients (8 men of median age 74, range 69-87, years) who developed clinical and laboratory evidence of coagulopathy during attempted repair of ruptured infrarenal AAA were prospectively studied. Platelet count, fibrinogen, clotting times, prothrombin fragment (PF) 1+2, and tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) activities were measured preoperatively, immediately before, and 5 min and 24 hr after aortic declamping. Six patients died, three intraoperatively, one within 24 hr, and two in the late postoperative period. All patients had thrombocytopenia and prolonged clotting times intraoperatively with evidence of increased thrombin generation (as demonstrated by elevated PF 1+2). Five patients had increased systemic fibrinolysis (as demonstrated by elevated t-PA activity) preoperatively and/or before aortic declamping and all of these patients died. Three patients had perioperative inhibition of systemic fibrinolysis (as demonstrated by elevated PAI activity) and two survived. These data demonstrate that coagulopathy in ruptured AAA repair may be associated with a hyperfibrinolytic state. Further research is required to determine if (a) a causal relationship exists between hyperfibrinolysis and coagulopathy and (b) whether antifibrinolytic agents can improve outcome if targeted at this group of patients.

Long-term survival and temporal trends in patient and surgeon factors after elective and ruptured abdominal aortic aneurysm surgery

OBJECTIVE

Records for all patients in Ontario who underwent elective repair of abdominal aortic aneurysms (AAAs) or repair of ruptured AAAs between 1993 and 1999 were studied to determine whether the profile of surgeons or patients changed and to determine whether postoperative mortality changed over time. The secondary objective was to describe long-term survival after AAA surgery.

METHODS

A population-based retrospective cohort was assembled from administrative data. Surgeon billing records were used to identify operations performed between 1993 and 1999. Chi(2) and linear regression analyses were used to determine whether variables changed over time. Kaplan-Meier survival curves were used to estimate long-term survival.

RESULTS

For patients undergoing elective AAA repair, average annual surgeon volume (P <.0001) and proportion of patients operated on by vascular surgeons (P =.02) increased over the study period; similar trends were noted for patients undergoing repair of ruptured AAAs. Surgeon volume was clearly correlated with mortality after both elective AAA repair and repair of ruptured AAAs; however, the benefit of this effect was modest beyond a surgeon volume of 6 to 10 ruptured AAA repairs per year or 20 to 30 elective AAA repairs per year. No change in crude 30-day mortality (4.5% for elective AAA repair and 40.4% for repair of ruptured AAAs) was noted during the study.

CONCLUSION

Despite the finding that surgery to repair ruptured AAAs and elective repair of AAAs is being increasingly performed by high-volume vascular surgeons, there was no change in early mortality between 1993 and 1999. This may have been because average surgeon volume was already relatively high at the beginning of the study period, which translated into only modest benefit to further increases in surgeon volume.

Ruptured inflammatory abdominal aortic aneurysm: insights in clinical management and outcome

BACKGROUND

Ruptured inflammatory abdominal aortic aneurysm (AAA) is relatively rare, and little has been written on the outcome of operative treatment.

METHODS

Patients undergoing attempted repair of ruptured inflammatory AAA between 1995 and 2001 were included in a retrospective case-cohort study. Demographic, clinical, and operative factors were analyzed, together with in-hospital morbidity, in-hospital mortality, and duration of postoperative hospital stay.

RESULTS

Of 297 patients who underwent attempted operative repair of ruptured AAA, 24 (8%) had an inflammatory aneurysm. Twenty-two patients were men, and two were women; median age was 69 years (range, 51-85 years). Operative findings revealed a contained hematoma in 16 patients (70%), free rupture in 3 patients (13%), aortocaval fistula in 4 patients (17%), and aortoenteric fistula in 1 patient (4%). Of 273 noninflammatory ruptured AAAs, only 2 AAA (1%) were associated with primary aortic fistula. Ten patients (42%) with inflammatory AAA died in hospital, compared with 117 of 273 patients (43%) without inflammation. Median postoperative stay was 10 days (range, 0-35 days). Of the 14 patients with inflammatory lesions who survived, 11 had postoperative complications; 4 patients had acute renal failure, three of whom required temporary renal replacement therapy.

CONCLUSIONS

Ruptured inflammatory AAA is associated with a higher incidence of aortic fistula than is ruptured noninflammatory AAA. Repair of ruptured inflammatory AAA is not associated with increased operative mortality compared with repair of ruptured noninflammatory AAA.

The post-operative mortality of ruptured abdominal aortic aneurysm repair

INTRODUCTION

Late peri-operative death after ruptured abdominal aortic aneurysm (RAAA) repair is usually due to multiple-organ failure. The aim of this study was to identify any factors that are associated with mortality in this group of patients.

METHODS

A retrospective case-note review of a single decade's operative experience of RAAA repair in a single centre. Only those patients with confirmed rupture at laparotomy were included. Sixty-three pre- intra- and post-operative variables were recorded where possible for each patient who survived surgery and the initial 24-hours post-operatively. Multi-variate analysis was performed using stepwise logistic regression. The P-POSSUM, RAAA-POSSUM, RAAA-POSSUM (physiology only), V-POSSUM, and V-POSSUM (physiology only) models were all compared to determine how each performed in these patients.

RESULTS

Two hundred and twenty-three cases of confirmed RAAA were identified, of whom 139 survived the operation and initial 24-hours post-operatively. In-hospital mortality in this group of patients was 32.4%. Variables significantly associated with mortality after multi-variate analysis, were low intra-operative systolic blood pressure, the presence of a consultant anaesthetist at the initial operation and the development of cardiac, renal or gastro-intestinal complications. All POSSUM models except the V-POSSUM and P-POSSUM (physiology only) models demonstrated no significant lack of fit in this dataset.

DISCUSSION

Factors associated with delayed peri-operative death after RAAA are not the same as those previously found to be associated with overall peri-operative mortality after RAAA repair.

Ethnicity and peripheral arterial disease

INTRODUCTION

the prevalence of peripheral arterial disease (PAD) is relatively well defined for the Caucasian population. Given the susceptibility of Asians and Afro-Caribbeans to coronary heart disease and stroke respectively, and the high prevalence of cardiovascular risk factors in both groups, one would expect a high prevalence of peripheral arterial disease.

METHODS

a search of MEDLINE (1966-2002) was undertaken for studies on the incidence and prevalence of PAD, abdominal aortic aneurysms (AAA) and cerebrovascular disease in different ethnic groups.

RESULTS

there are very few population-based prevalence studies assessing PAD, AAA or cerebrovascular disease in non-Caucasians. A review of hospital-based series demonstrates different patterns of PAD between ethnic groups. Blacks and Asians have a tendency towards more distal occlusive disease and AAA appear to be predominantly a disease of Caucasians. It is not clear whether these studies provide a true representation of the prevalence of arterial disease in various ethnic groups or are the result of an unmet health care need.

CONCLUSIONS

further studies are required to establish the prevalence, natural history and response to treatment of PAD, AAA and cerebrovascular disease in non-Caucasians. Only when this has been achieved, can clinically and cost-effective health care be delivered to affected individuals from different ethnic groups.

The endovascular management of ruptured abdominal aortic aneurysms

Endovascular aneurysm repair (EVAR) is a controversial technique, which remains the subject of a number of prospective randomised trials. Although questions remain regarding its long-term durability objective evidence exists which demonstrates its reduced physiological impact compared with conventional open repair. If this technique could be used in patients with ruptured abdominal aortic aneurysm (AAA) it may reduce the high peri-operative mortality. A review of the literature identified a limited experience with EVAR of ruptured AAA. Only a small number of case series with selected patients exist. The majority of patients were haemodynamically stable. However, the selective use of aortic occlusion balloons allowed successful endovascular management in a small number of unstable cases. All investigators had access to an "off the shelf" endovascular stent-graft (EVG). Per-operative mortality ranged from 9 to 45% and may reflect increasing experience and patient selection. A number of patients who underwent successful EVAR were turned down for open repair. A number of important lessons have been learned from these studies but questions remain regarding patient suitability and staffing issues. If these difficulties can be surmounted then the technique may offer an alternative to open repair.

The relationship between aortic wall distensibility and rupture of infrarenal abdominal aortic aneurysm

OBJECTIVE

A more accurate means of prediction of abdominal aortic aneurysm (AAA) rupture would improve the clinical and cost effectiveness of prophylactic repair. The purpose of this study was to determine whether AAA wall distensibility can be used to predict time to rupture independently of other recognized risk factors.

METHODS

A prospective, six-center study of 210 patients with AAA in whom blood pressure (BP), maximum AAA diameter (Dmax), and AAA distensibility (pressure strain elastic modulus [Ep] and stiffness [beta]) were measured at 6 months with an ultrasound scan-based echo-tracking technique. A stepwise, time-dependent, Cox proportional hazards model was used to determine the effect on time to rupture of age, gender, BP, Dmax, BP, Ep, beta, and change in Dmax, Ep, and beta adjusted for time between follow-up visits.

RESULTS

Median (interquartile range) AAA diameter was 48 mm (41 to 54 mm), median age was 72 years (68 to 77 years), and median follow-up period was 19 months (9 to 30 months). In the Cox model, female gender (hazards ratio [HR], 2.78; 95% CI, 1.23 to 6.28; P =.014), larger Dmax (HR, 1.36 for 10% increase in Dmax; 95% CI, 1.12 to 1.66; P =.002), higher diastolic BP (HR, 1.13 for 10% increase in BP; 95% CI, 1.13 to 1.92; P =.004), and a decrease in Ep (increase in distensibility) over time (HR, 1.38 for 10% decrease in Ep over 6 months; 95% CI, 1.08 to 1.78; P =.010) significantly reduced the time to rupture (had a shorter time to rupture).

CONCLUSION

Women have a shorter time to AAA rupture. The measurement of AAA distensibility, diastolic BP, and diameter may provide a more accurate assessment of rupture risk than diameter alone.

A CUSUM analysis of ruptured abdominal aortic aneurysm repair

Studies have investigated the role of hospital and surgeon case volume in outcome after ruptured abdominal aortic aneurysm repair (rAAA). Few have analyzed the learning curve of an individual surgeon. The purpose of this study was to analyze this learning curve in reducing morbidity and mortality after rAAA repair. Thirty-two consecutive patients who underwent rAAA repair during the initial 2.5 years of a vascular surgeon's career were reviewed retrospectively. They were divided temporally into two groups of 16 patients (groups 1 and 2). Outcome measures included mortality, postoperative myocardial infarction, stroke, and renal and respiratory failure. Perioperative variables previously associated with increased mortality were analyzed. The cumulative sum (CUSUM) method was used to analyze the learning curve with respect to published acceptable event rates and predetermined 80% alert and 95% alarm boundary lines. Groups 1 and 2 did not differ statistically in age, preoperative blood pressure, hemoglobin or creatinine. There was no difference in transfusion requirements (6.8 +/- 1.2 units vs. 6.4 +/- 1.0 units; p = 0.78), urine output (340 +/- 65 mL vs. 389 +/- 94 mL; p = 0.72) or clamp position. There was no difference in the incidence of postoperative myocardial infarction, stroke, or respiratory or renal failure. Thirty-day mortality in group 2 was 12% as compared to 50% in Group 1 (p = 0.03). On CUSUM analysis, the cumulative failure rate in group 2 progressed lower than the 80% reassurance line, indicating improved results with time. Mortality after rAAA repair decreased over time during an early period of an individual surgeon's career. The CUSUM method is a valuable tool in analyzing an individual surgeon's experience and shows promise in quality control in vascular surgery.

Endovascular versus conventional open repair of acute abdominal aortic aneurysm: feasibility and preliminary results

PURPOSE

To evaluate the feasibility of endovascular treatment of acute abdominal aortic aneurysm (AAA) with commercially prepared bifurcated systems.

METHODS

From January through July 2001, 22 patients (17 men; mean age 73.6 years, range 59-89) were referred with an acute (symptomatic/ruptured) AAA. Six patients were treated with emergent open surgery because of hemodynamic instability, but the other 16 patients underwent computed tomographic angiography with multidirectional reconstruction. Six (27%) aneurysms were suitable for endovascular repair (EVR) and were successfully treated. Procedural variables, morbidity, and mortality were compared between the EVR group and 6 patients of equivalent hemodynamic status from among the conventionally treated patients.

RESULTS

There was no mortality in either group. The median aneurysm diameter in the EVR group was 63 mm (range 48-84) versus 80 mm (45-82) in the matched surgically treated AAAs (p=0.628). Procedural duration was 193 minutes (150-265) for the EVR group compared to 203 minutes (130-270) for the matched group (p=0.630). Median blood loss was significantly less (p=0.010) in the EVR group (125 versus 3400 mL). Median length of stay (LOS) in intensive care was 8 hours (0-21) versus 62 hours (48-112) for the surgical group (p=0.004). Hospital LOS was significantly reduced (p=0.024) for the EVR patients (7.5 [2-16] versus 15.5 [10-34] days).

CONCLUSIONS

Endovascular treatment of acute aneurysm is feasible, and preliminary results are promising.

Endovascular grafts and other image-guided catheter-based adjuncts to improve the treatment of ruptured aortoiliac aneurysms

OBJECTIVE

To report a new management approach for the treatment of ruptured aortoiliac aneurysms.

METHODS

This approach includes hypotensive hemostasis, minimizing fluid resuscitation, and allowing the systolic blood pressure to fall to 50 mmHg. Under local anesthesia, a transbrachial guidewire was placed under fluoroscopic control in the supraceliac aorta. A 40-mm balloon catheter was inserted over this guidewire and inflated only if the blood pressure was less than 50 mmHg, before or after the induction of anesthesia. Fluoroscopic angiography was used to determine the suitability for endovascular graft repair. When possible, a prepared, "one-size-fits-most" endovascular aortounifemoral stented PTFE graft was used, combined with occlusion of the contralateral common iliac artery and femorofemoral bypass. If the patient's anatomy was unsuitable for endovascular graft repair, standard open repair was performed using proximal balloon control as needed.

RESULTS

Twenty-five patients with ruptured aortoiliac aneurysms (18 aortic, 7 iliac) were managed using this approach. Balloon inflation for proximal control was required in nine of the 25 patients. Twenty patients were treated with endovascular grafts. Five patients required open repair. The ruptured aneurysm was excluded in all 25 patients; 23 survived. Two deaths occurred in patients who received endovascular grafts with serious comorbidities. The surviving patients who received endovascular grafts had a median hospital stay of 6 days, and the preoperative symptoms resolved in all patients.

CONCLUSIONS

Hypotensive hemostasis is usually an effective means to provide time for balloon placement and often for endovascular graft insertion. With appropriate preparation and planning, many if not most patients with ruptured aneurysms can be treated by endovascular grafts. Proximal balloon control is not required often but may, when needed, be an invaluable adjunct to both endovascular graft and open repairs. The use of endovascular grafts and this approach using other image-guided catheter-based adjuncts appear to improve treatment outcomes for patients with ruptured aortoiliac aneurysms.

pHi monitoring of the sigmoid colon after aortoiliac surgery. A five-year prospective study

OBJECTIVES

to determine whether sigmoid-pHi diagnose colon ischaemia after aortoiliac surgery?

DESIGN

single-centre, non-randomised, prospective study.

PATIENTS AND METHODS

of 83 patients operated on between 1994 and 1998, 41 with risk factors for the development of colon ischaemia were monitored peri- and/or postoperatively with sigmoid-pHi. Peri-operative mortality was 26% (8/31) after operation for a ruptured abdominal aortic aneurysm (AAA), nil after operation for non-ruptured AAA. Thirty-five postoperative colonoscopies were performed. All non-survivors were examined post-mortem.

RESULTS

of six patients developing colon ischaemia after emergency operations (five for ruptured AAA) all had pHi-values <7.1 for 16-80 h. In two patients with transmural gangrene, and who had pHi-values below 6.6, pHi-monitoring permitted early diagnosis, colectomy and recovery. Three patients with mucosal gangrene were treated conservatively and recovered. Nine patients without ischaemic lesions had pHi-values <7.1, during 1-5 h, without adverse outcome. Bilateral ligation of the internal iliac arteries increased the risk of colon ischaemia (p<0.0001).

CONCLUSIONS

pHi-monitoring was diagnostic for colon ischaemia. Mucosal and transmural gangrene were distinguished. The importance of the internal iliac circulation was demonstrated. The low mortality rate, and the fact that no patient died from bowel ischaemia, suggests that sigmoid pHi-monitoring may improve survival after ruptured AAA.

An endoluminal method of hemorrhage control and repair of ruptured abdominal aortic aneurysms

PURPOSE

To report our initial experience with endovascular grafting to treat ruptured abdominal aortic aneurysms (AAAs).

METHODS

Three consecutive patients with severe comorbid illnesses and symptoms of aneurysm rupture and hemodynamic instability were treated with aortomonoiliac grafts. The Z-stent-based devices were implanted with the assistance of an occlusion balloon placed in the distal descending thoracic aorta.

RESULTS

All patients survived the procedure with successfully excluded AAAs. Two patients had relatively short hospital stays (4 and 14 days), while the third required prolonged treatment for pre-existing conditions. All patients required blood transfusions; 2 developed significant coagulopathies. Definitive management was delayed significantly by imaging protocols and graft construction.

CONCLUSIONS

Endovascular repair of ruptured aortic aneurysms is feasible. Proximal aortic control is readily attainable with the use of an aortic occlusion balloon placed through the left axillary artery. The absence of a laparotomy, extensive retroperitoneal dissection, and aortic cross-clamping likely contributes to patient survival; however, the delay in operative therapy to obtain adequate imaging and construct an endograft could be a hindrance to the ultimate success of this approach. The concepts of alternative aortic imaging techniques and endograft design, construction, and storage must be addressed.

Ruptured abdominal aortic aneurysm: a novel method of outcome prediction using neural network technology

BACKGROUND

reported survival following emergency surgery for ruptured abdominal aortic aneurysm (RAAA) varies widely between institutions. This is largely attributable to differences in case mix. The aim of this study was to identify and evaluate a set of prognostic variables that would accurately predict outcome for individual patients from perioperative indices.

METHODS

perioperative factors associated with subsequent mortality at our institution were identified by retrospective review of 102 consecutive operations for RAAA over a 7-year period (January 1990 to January 1997). Logistic regression analysis was used to select the most significant variables associated with subsequent mortality. These were used to construct, train, and validate a neural network designed to predict survival from surgery in individual cases on a prospective basis.

RESULTS

the 30-day mortality rate was 53%. Multivariate analysis identified four highly significant independent predictors of mortality; preoperative hypotension, intraperitoneal rupture, preoperative coagulopathy, and preoperative cardiac arrest. Using these inputs, the neural network correctly predicted outcome in 82.5% of individual cases.

CONCLUSION

a neural network based on just four perioperative variables can accurately predict outcome of RAAA. Prognostic variables should be reported in studies as a measure of the effect of case mix on survival data. Neural networks have potential to aid decision-making relating to outcome for individual cases.

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.

Coagulation and fibrinolysis in patients undergoing operation for ruptured and nonruptured infrarenal abdominal aortic aneurysms

PURPOSE

Hemorrhage and thrombosis predisposing to myocardial infarction, multiple organ failure, and thromboembolism account for the majority of the morbidity and mortality associated with repair of ruptured and nonruptured abdominal aortic aneurysms (AAAs). The aim of this study was to examine coagulation and fibrinolysis in patients operated on for ruptured and nonruptured infrarenal AAAs.

METHODS

Ten patients operated on for ruptured and 9 patients operated on for nonruptured AAAs were studied. Tissue plasminogen activator (t-PA) antigen, thrombin-antithrombin (TAT), and D-dimer were measured before induction of anesthesia. Plasminogen activator inhibitor (PAI) activity, t-PA activity, and prothrombin fragment (PF) 1+2 were measured before induction of anesthesia, immediately before aortic clamp release, and 5 minutes and 24 hours after aortic clamp release.

RESULTS

Preoperatively, ruptured AAA was associated with significantly elevated t-PA antigen (median 15.7 ng/mL, range 9. 0 to 22.1 ng/mL versus nonrupture: median 6.6 ng/mL, range 4.7 to 16. 4 ng/mL; P <.01, Mann-Whitney test), increased PAI activity (median 36.5 arbitrary units/mL, range 20.6 to 38.8 arbitrary units/mL versus nonrupture: median 8.2 arbitrary units/mL, range 3.2 to 21.7 arbitrary units/mL; P <.001), reduced t-PA activity (median 0.12 IU/mL, range 0.06 to 0.4 IU/mL versus nonrupture: median 0.49 IU/mL, range 0.14 to 3.2 IU/mL; P <.01), elevated TAT (median 135.5 microg/L, range 61.2 to 209.4 microg/L versus nonrupture: median 21. 6 microg/L, range 6.6 to 180.4 microg/L; P <.02) and elevated PF 1+2 (median 9.0 nmol/L, range 5.4 to 11.6 nmol/L versus nonrupture: median 2.2 nmol/L, range 0.7 to 7.1 nmol/L, P <.001). There was no significant difference in preoperative D-dimer levels (median 3460 ng/mL, range 1236 to 7860 ng/mL versus nonrupture: median 1642 ng/mL, range 728 to 5334 ng/mL; P =.07). The differences in PAI activity, t-PA activity, and PF 1+2 persisted throughout the course of surgery, but there was no significant difference between the groups at 24 hours.

CONCLUSION

These novel data demonstrate that ruptured AAA repair is associated with inhibition of systemic fibrinolysis and intense thrombin generation. Similar changes are seen in nonruptured AAA but are of a lesser magnitude. This procoagulant state may contribute to the microvascular and macrovascular thrombosis that leads to myocardial infarction, multiple organ failure, and thromboembolism.

Risk factors for aneurysm rupture in patients kept under ultrasound surveillance. UK Small Aneurysm Trial Participants

OBJECTIVE

To investigate risk factors associated with aneurysm rupture using patients randomized into the U.K. Small Aneurysm Trial (n = 1090) or monitored for aneurysm growth in the associated study (n = 1167).

SUMMARY BACKGROUND DATA

The U.K. Small Aneurysm Trial has shown that ultrasound surveillance is a safe management option for patients with small abdominal aortic aneurysms (4.0 to 5.5 cm in diameter), with an annual rupture rate of 1%.

METHODS

In the cohort of 2257 patients (79% male), aged 59 to 77 years, 103 instances of abdominal aortic aneurysm rupture were identified during the 7-year period of follow-up (1991-1998). Almost all patients (98%) had initial aneurysm diameters in the range of 3 to 6 cm, and the majority of ruptures (76%) occurred in patients with aneurysms > or =5 cm in diameter. Kaplan-Meier survival and Cox regression analysis were used to identify baseline risk factors associated with aneurysm rupture.

RESULTS

After 3 years, the annual rate of aneurysm rupture was 2.2% (95% confidence interval 1.7 to 2.8). The risk of rupture was independently and significantly associated with female sex (p < 0.001), larger initial aneurysm diameter (p < 0.001), lower FEV1 (p = 0.004), current smoking (p = 0.01), and higher mean blood pressure (p = 0.01). Age, body mass index, serum cholesterol concentration, and ankle/brachial pressure index were not associated with an increased risk of aneurysm rupture.

CONCLUSIONS

Within this cohort of patients, women had a threefold higher risk of aneurysm rupture than men. Effective control of blood pressure and cessation of smoking are likely to diminish the risk of rupture.

The relationship between abdominal aortic aneurysm wall compliance, maximum diameter and growth rate

AIM

Aortic compliance as measured by the pressure-strain elastic modulus (Ep) and stiffness (beta), may allow a more precise estimate of rupture risk. The aim of this study was to determine the relationships between compliance, maximal aneurysm diameter and growth rate.

METHODS

Sixty abdominal aortic aneurysm patients of median age 73 years, were studied. Growth rate was derived from repeat ultrasound scans obtained over a median period of 21 months (range 6-48). At the end of follow-up, patients underwent measurement of maximum aortic diameter, Ep and beta using the Diamove echo-tracking system.

RESULTS

Growth rate correlated positively (r = 0.6, P < 0.01) with maximum diameter on entry to the study There was a positive correlation between mean arterial pressure and Ep (r = 0.3, P = 0.03), but not between mean arterial pressure and beta (r = 0.8, P = 0.61). A positive correlation was found between final maximum diameter and Ep (r = 0.22, P = 0.04) but not beta (r = 0.16, P = 0.11). There was no significant relationship between growth rate and Ep or beta.

CONCLUSION

Large aneurysms tended to be less compliant. Within a population of abdominal aortic aneurysm of similar maximum diameter there was a 10-fold variation in Ep and beta. Compliance and growth rate were not related. If aortic compliance is related to risk of rupture then this predictive information is likely to be largely independent of that currently obtained from size and growth rate.

Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants

BACKGROUND

Early elective surgery may prevent rupture of abdominal aortic aneurysms, but mortality is 5-6%. The risk of rupture seems to be low for aneurysms smaller than 5 cm. We investigated whether prophylactic open surgery decreased long-term mortality risks for small aneurysms.

METHODS

We randomly assigned 1090 patients aged 60-76 years, with symptomless abdominal aortic aneurysms 4.0-5.5 cm in diameter to undergo early elective open surgery (n=563) or ultrasonographic surveillance (n=527). Patients were followed up for a mean of 4.6 years. If the diameter of aneurysms in the surveillance group exceeded 5.5 cm, surgical repair was recommended. The primary endpoint was death. Mortality analyses were done by intention to treat.

FINDINGS

The two groups had similar cardiovascular risk factors at baseline. 93% of patients adhered to the assigned treatment. 309 patients died during follow-up. The overall hazard ratio for all-cause mortality in the early-surgery group compared with the surveillance group was 0.94 (95% CI 0.75-1.17, p=0.56). The 30-day operative mortality in the early-surgery group was 5.8%, which led to a survival disadvantage for these patients early in the trial. Mortality did not differ significantly between groups at 2 years, 4 years, or 6 years. Age, sex, or initial aneurysm size did not modify the overall hazard ratio.

INTERPRETATION

Ultrasonographic surveillance for small abdominal aortic aneurysms is safe, and early surgery does not provide a long-term survival advantage. Our results do not support a policy of open surgical repair for abdominal aortic aneurysms of 4.0-5.5 cm in diameter.

The value of computed tomography in the assessment of suspected ruptured abdominal aortic aneurysm

OBJECTIVE

The objective of this study was to determine the diagnostic value of computed tomography (CT) in patients with suspected ruptured abdominal aortic aneurysm.

STUDY DESIGN

The study was an interrogation of a prospectively gathered computerized database.

SETTING

The study was performed at a regional vascular surgery unit.

SUBJECTS

Six hundred fifty-two consecutive patients were admitted to this unit with suspected ruptured abdominal aortic aneurysm between January 1, 1989, and December 31, 1996. Seventy-four patients (11.3%) in whom the diagnosis was in doubt on clinical grounds alone underwent urgent CT. A total of 47 men and 27 women with a median age of 73 years (range, 52 to 86 years) were evaluated.

MAIN OUTCOME MEASURES

CT and operative findings were compared.

RESULTS

CT correctly diagnosed rupture in 22 of 28 patients who underwent operation and correctly excluded rupture in 30 of 39 patients who underwent operation. The sensitivity and specificity of CT when compared with operative findings were therefore 79% and 77%, respectively.

CONCLUSIONS

These data indicate that CT has little additional diagnostic value. If in the opinion of an experienced vascular surgeon rupture cannot be excluded on clinical grounds alone, and the patient has no medical contraindications to abdominal aortic aneurysm repair, then the patient should be taken directly to the operating department.