Implications of screening for abdominal aortic aneurysms on surgical workload

BACKGROUND: The Multicentre Aneurysm Screening Study (MASS) provided strong evidence for both the clinical benefit and the cost-effectiveness of a screening programme for abdominal aortic aneurysms (AAAs) in men. If a national screening programme for AAA were adopted in the UK, it would be expected to increase the elective and decrease the emergency surgical workload. METHODS: The MASS trial randomized 67,800 men aged 65-74 years to be invited to attend for ultrasonographic screening for AAA or to a control group that received no invitation. Predictions of elective and emergency surgical workload were made for a 20-year interval after the introduction of a screening programme for 65-year-old men, based on surgical rates observed in the MASS trial and national mortality statistics. RESULTS: For a district general hospital serving a population of 400,000, there was an estimated reduction from nine emergency operations per year before introduction of the screening programme to three emergency operations annually in men aged 65 years and over by the end of the 20-year interval, and an increase from 24 to 43 AAA operations overall. The corresponding estimated annual costs for all AAA surgery increased by 47 per cent, from pound 209,000 to pound 308,000. These results were not affected by changes in the underlying assumptions. CONCLUSION: The results support the expectation of very few emergency operations, and principally elective operations, being performed following the introduction of a screening programme. For a typical district general hospital, a screening programme would be expected to lead to two additional elective AAA operations per month, and to save 11 AAA-related deaths per year.     

A comparison of the mortality rate after elective repair of aortic aneurysms detected either by screening or incidentally.

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

Epidemiology and Outcome of Aortic Aneurysms in Hong Kong

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

Abdominal aortic aneurysm rupture rates: A 7-year follow-up of the entire abdominal aortic aneurysm population detected by screening

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

A cost analysis of surgery for ruptured abdominal aortic aneurysm.

OBJECTIVE: This study compares our costs of salvaging patients with ruptured abdominal aortic aneurysms (AAA) with the costs for unruptured AAAs. METHODS: Details of all AAAs presenting over 18 months were obtained. Costs of repair were carefully calculated for each case and were based upon ITU and ward stay and the use of theatre, radiology and pathology services. We compared the costs in unruptured AAAs with both uncomplicated ruptures and ruptures with one or more system failure. RESULTS: The mortality rate for ruptures undergoing repair was 18% and for elective repairs was 1.6%. The median cost for uncomplicated ruptures was 6427 Pounds (range 2012-13,756 Pounds). For 12 complicated ruptures, it was 20,075 Pounds (range 13,864-166,446 Pounds), and for 63 unruptured AAAs, was 4762 Pounds (range 2925-47,499 Pounds). CONCLUSION: Relatively low operative mortality rates for ruptured AAA repair can be achieved but this comes at substantial cost. On average, a ruptured AAA requiring system support costs four times as much as an elective repair.     

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

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

Abdominal aortic aneurysm: the role of clinical examination and opportunistic detection.

OBJECTIVES: to investigate the method of discovery of abdominal aortic aneurysms (AAA) in a district general hospital setting. Design: retrospective study. MATERIALS AND METHODS: we analysed 198 patients with an AAA who presented to our unit over a 3-year period. The method of initial diagnosis, size of the AAA and whether this was palpable, irrespective of the method of detection, were recorded. RESULTS: ninety-five (48%) were discovered clinically, 74 (37.4%) during a radiological investigation, and 29 (14.6%) at laparotomy. Of the 74 AAAs first detected radiologically, subsequent physical examination showed that 28 (37.8%) were in fact palpable and missed at presentation. The average size of those discovered clinically (6. 48+/-1.32 cm) was larger than those found radiologically (5.37+/-1. 44 cm, p<0.001) or at operation (5.43+/-1.48 cm, p=0.039). The average diameter of the palpable AAAs was also greater than that of the non-palpable AAAs (6.42+/-1.24 cm vs. 4.86+/-1.38 cm, p<0.001). CONCLUSIONS: opportunistic detection of a clinically unsuspected aneurysm during clinical examination or investigation for another reason is the most common way the diagnosis of an AAA is made. Almost half of the aneurysms were diagnosed clinically, but physical examination also missed more than a third of those detected radiologically. Despite technological advancement, clinical examination still plays a paramount role in the detection of AAAs. Larger AAAs are usually palpable and more likely to be detected on clinical examination.     

A myth exposed: fast growth in diameter does not justify precocious abdominal aortic aneurysm repair.

OBJECTIVES: fast growth of abdominal aortic aneurysm (AAA) diameter is claimed to be an indication for repair. We investigated the validity of this claim. METHODS: between January 1988 and October 2000, 277 patients have had duplex sonography at six-monthly intervals in our aneurysm surveillance programme. During this period fast AAA growth was not an indication for operation in our unit. RESULTS: we identified 63 patients whose aneurysms had grown 0.5 cm or more in 6 months. Thirty-one of the 63 patients had aneurysms measuring 5.5 cm or greater in anterior-posterior diameter after the fast growth and all have been operated on unless deemed not fit due to anaesthetic risk. The remaining 32 patients continued in surveillance for a total of 50 patient years and none had rupture of their aneurysm. The calculated 95% confidence interval for the risk of rupture was 0-6 per 100 patient years. Six patients, who would have been operated on if fast growth had been an indication, have been spared surgery of whom 3 died and 3 became unfit. Nine patients remained in surveillance at the end of the study. CONCLUSION: our data support the view that rapid increase in AAA diameter is not an indication for elective AAA repair.     

Isolated iliac artery aneurysms in patients with or without previous abdominal aortic aneurysm repair.

BACKGROUND: Isolated iliac artery aneurysms (IAA) in patients with or without previous abdominal aortic aneurysm (AAA) repair are rare. We wanted to compare the presentation, distribution, treatment, outcome and patterns of subsequent aneurysm formation in these patients. METHODS: We retrospectively reviewed patients with isolated IAA over a 10-year period. Patients with primary isolated IAA (group 1) were compared with patients who presented with IAA after previous AAA repair (group 2). RESULTS: There were 23 patients in each group. Demographics and comorbidities were similar. No aneurysms were detected outside of the iliac system in group 1; 22% of patients in group 2 had other aneurysms. The mean time after AAA repair to IAA diagnosis was 8.8 +/- 3.2 years for operated on patients. The in-hospital mortality was 0% for elective cases and 50% for emergency cases for both groups. Three patients in group 2 (13%) developed new aneurysms during follow-up, whereas the only new aneurysm in group 1 was a contralateral IAA. CONCLUSIONS: Patients with new IAA after AAA repair have a greater tendency to develop further aneurysms in other sites, synchronously or metachronously. The time to detection of new IAA after AAA repair is at least 5 years in most cases. In both groups, a quarter to a third of patients present with rupture, with a resultant mortality of 30% to 50%, whereas those operated on electively have minimal morbidity and almost no mortality.     

Treatment delays for patients exiting an aortic aneurysm surveillance programme

Background: We have previously reported abdominal aortic aneurysm (AAA)‐related mortality in patients who have completed surveillance. This study investigates the journey time of patients who exited the AAA surveillance programme at Christchurch Hospital and underwent elective repair to determine the factors contributing to the interval between completing surveillance and undergoing surgical repair. Methods: A retrospective review of patient notes was carried out for 25 patients who underwent elective repair of their AAA after exiting the surveillance programme between November 2000 and September 2005. Results: The median time interval between exiting the programme and undergoing repair for patients fit for repair was 6 months. During this waiting period, there were two aneurysm‐related deaths. Analysis of the patient journeys showed that those with significant comorbidity, that is, patients who required additional investigation by other clinicians (n = 7), had a median time to repair of 35 weeks. This was substantially increased compared with a median time of 22.5 weeks to repair for the rest (n = 18). Conclusion: At our institution the median time for completion of surveillance to repair was 6 months. An AAA with a diameter of 55 mm has an expected risk of rupture of 5%, with mortality approaching 90%. In our series, mortality was 4.9% (two patients died while awaiting repair), consistent with expected figures. Factors contributing to this delay of 6 months to repair were identified. Modifications to this journey are suggested to improve the time interval and therefore hopefully reduce the aneurysm‐related mortality in this group.     

Ultraschallscreening auf abdominale Aortenaneurysmen (AAA)

Background

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

Materials and methods

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

Results

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

Conclusion

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

Conservative observational management with selective delayed repair for large abdominal aortic aneurysms in high risk patients

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

Audit of 200 consecutive aortic aneurysm repairs carried out by a single surgeon in a district hospital: results of surgery and factors affecting outcome.

It has been suggested that surgery for abdominal aortic aneurysm (AAA) be confined to designated centres. A prospective audit of 200 consecutive AAA repairs at a district general hospital was performed between 1981 and 1990. The 30-day mortality rates for elective, symptomatic and ruptured aneurysm repair were 1.4%, 3.5% and 30%, respectively. The major factor affecting outcome after the mode of presentation was the age of the patient, with 30-day mortality rates for emergency treatment increasing from 21% (age range 60-69 years) to 42% (age range 70-79 years). This mortality rate for ruptured aneurysms is an underestimate, with two-thirds of patients with rupture dying before reaching hospital and some patients dying in hospital undiagnosed. The major contribution to improved overall mortality would therefore be detection before rupture (usually by ultrasound) and improved diagnostic accuracy. Many patients with ruptured aneurysms had symptoms for only a short period before presentation (42% for less than 6 h) and required urgent surgery (26% reached theatre within 1 h). These two factors make long-distance transfer of these patients an unrealistic option. The concentration of this type of surgery in relatively few centres will distance the patient from their relatives and reduce the opportunity for the majority of junior doctors to acquire an understanding of the presentation, natural history and management of aortic aneurysms. This understanding when combined with a screening programme is likely to have a far greater impact on the overall mortality from AAA than restricting the centres for surgical treatment.     

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

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

Nonoperative management with selective delayed surgery for large abdominal aortic aneurysms in patients at high risk

OBJECTIVE: An accepted fact is that abdominal aortic aneurysms (AAAs) larger than 5.5 cm should undergo elective repair. However, subsets of these patients have serious comorbid conditions, which greatly increase operative risk. This study evaluated the outcomes of periods of protracted nonoperative observational management with selective delayed surgery in patients at high risk with large infrarenal and pararenal AAAs. METHODS: Among 226 patients with AAAs more than 5.5 cm, we selected 72 with AAAs from 5.6 to 12.0 cm (mean, 7.0 cm) for periods of nonoperative management because of their prohibitive surgical risks. Comorbid factors included a low ejection fraction of 15% to 34% (mean, 22%) in 18 patients, 1 second forced expiratory volume less than 50% (mean, 38%) in 25, prior laparotomy in 10, and morbid obesity in 22. Follow-up examination was complete in the 72 patients for the 6 to 76 months (mean, 23 months) that they underwent nonoperative treatment. Fifty-three patients ultimately underwent operation because of AAA enlargement or onset of symptoms after 6 to 72 months (mean, 19 months) of nonoperative treatment. RESULTS: Of the 72 selected patients, 54 (75%) are living and 18 (25%) are dead. Seven patients who underwent only nonoperative treatment presently survive after 28 to 76 months (mean, 48 months). Of the 18 deaths, AAA rupture occurred in only three patients (4%) who were observed for 12, 31, and 72 months before rupture. Nine other deaths (13%) occurred after 6 to 72 months from comorbidities unrelated to the AAA. Six of the 53 patients who underwent delayed operation died within 30 days of operation (11% mortality rate). The mortality rate for the 154 good-risk patients with an AAA who underwent prompt open or endovascular repair was 2.2%. CONCLUSION: These data indicate that some patients with large AAAs and serious comorbidities are acceptably managed for long periods (6 to 76 months) with nonoperative means. Substantial delays of 12 to 76 months resulted in an AAA rupture rate of only 4%, and 13% of these patients (nine of 72) died of comorbidities unrelated to AAA rupture or surgery. Mortality rate in this group of patients, when operated, was 11% (six of 53). These findings support the selective use of nonoperative management in some patients with large AAAs and serious comorbidities.     

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

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

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

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

The Long-term Benefits of a Single Scan for Abdominal Aortic Aneurysm (AAA) at Age 65

AIM: To investigate the efficacy of a single ultrasonic scan at age 65 to identify patients at risk from ruptured abdominal aortic aneurysm (AAA). METHOD: A total of 6058 men aged 64-81 were recruited to a randomised trial, and 3000 were invited to attend a single screening test. An additional population of 1011 men was offered screening as they reached age 65. If a normal aorta was identified in this sub-group, further scans were offered at two-yearly intervals. Follow up and treatment of those identified as having an aortic dilatation of 3 cm or greater was undertaken. All subject groups were monitored for deaths occurring over the study period, and date and cause of death were recorded. RESULTS: A total of 2212 men attended screening in the randomised trial; the overall compliance was 74%, and prevalence of AAA was 7.7%. Compliance decreased, and prevalence increased, with age. Mortality from ruptured AAA was reduced by 68% at 5 years (screened group compared to the age-matched control population), and by 42% in the study arm (screened and refusers) compared with controls. The benefit persisted at ten years (53% and 21% respectively). Of the uncontrolled sample of 1011 men offered a scan at age 65, 681 attended and 649 of these were found to have a normal aortic diameter; re-screening demonstrated new aneurysm development in 4% over ten years. The aortic diameters of the new AAAs were under 4 cm and would therefore have a low risk of rupture.1 Mortality from rupture in all those with an initially normal aortic diameter was low, at 1 case per 1000 scans over ten years. CONCLUSION: Screening once for AAA at age 65 can identify the majority of AAA that are of clinical significance and can identify a large population at low risk from rupture who do not require surveillance. This policy has been effective when combined with selective treatment in reducing the risk of rupture for ten years in those who attend the screening programme.     

Late survival after elective repair of aortic aneurysms detected by screening.

BACKGROUND: The aim of this study was to examine whether there was any survival advantage in men following elective repair of an abdominal aortic aneurysm (AAA) detected by ultrasound screening compared to those with an AAA detected incidentally. METHODS: A total of 424 men underwent elective AAA repair between 1990 and 1998; 181 were detected in an aneurysm screening programme and 243 were diagnosed incidentally. Follow-up survival data were collected until 2003 (minimum 5 years) and survival curves were compared using regression analysis. RESULTS: The postoperative 30-day mortality rate was significantly lower in men whose aneurysms were detected by screening (4.4%), compared with those detected incidentally (9.0%). Similarly, 5-year survival (78% vs. 65%) and 10-year survival rates (63% vs. 40%) were better after repair of a screen-detected AAA (p<0.0003 at all time intervals, by log rank testing). Multivariate analysis showed that this was largely due to the older age of men who had repair of an incidental AAA (71.2 vs. 67.1 years). CONCLUSION: Men who had elective repair of an AAA detected by screening had a better late survival rate than men whose aneurysm was discovered incidentally because they were younger at the time of surgery.