Elective aneurysm repair and the incidence of aortic rupture in an ageing population

During the period January 1984-July 1988, 191 abdominal aortic aneurysms were encountered at Gosford District Hospital, NSW, a hospital that services an ageing population. These aneurysms were either repaired or found as the cause of death at post-mortem. During the study, the rate of elective repair rose from 0.25/month during the first 2 years to 3.67/month in the latter 2.5 years. The mortality for repair of non-ruptured aneurysms was 0.9% compared with 55% for ruptured aneurysms. The 15-fold increase in elective repair resulted in the 58% reduction in the incidence of abdominal aortic rupture from 1.87/month to 0.79/month. The mortality rate from known aneurysms fell from 46% to 14% in the final 2 years. Elective aneurysm repair reduces the incidence of and death from abdominal aortic rupture in an ageing population.     

Clamp before you cut: Proximal control of ruptured abdominal aortic aneurysms using endovascular balloon occlusion--Case reports

While the mortality rate for elective abdominal aortic aneurysm (AAA) repair has declined over the last several decades, the rate for ruptured abdominal aortic aneurysm (RAAA) has unfortunately remained disturbingly high. Undiagnosed aneurysms may present with little warning until abdominal pain, syncope, and hypotension signify rupture. Fifty percent of patients with ruptured aneurysms die before reaching a medical facility, and their survival is highly dependent on hemodynamic stability at presentation. The degree of rupture containment and comorbid status of the patient determine hemodynamic stability. Endovascular stent grafting has significantly improved perioperative morbidity and mortality rates for elective AAA repair, and some of the same endovascular techniques can be used to obtain proximal control in patients presenting with RAAA. We describe 3 consecutive cases of RAAA where proximal control was obtained using a percutaneously placed, transfemoral aortic occlusion balloon before induction of anesthesia.     

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.     

One surgeon's ten-year experience with abdominal aortic aneurysm surgery in smaller community hospitals

The results of one surgeon's 10-year experience with surgical treatment of abdominal aortic aneurysms are reviewed. There were 64 elective operations, eight operations on expanding aneurysms, and 19 procedures done for frank rupture. The mortality rate was 4.2% for the nonruptured aneurysm group compared with 36.8% for those patients with rupture. It may be suggested from this study that surgical treatment of abdominal aortic aneurysms can be done safely in low volume in smaller community hospitals and that such surgery need not be regionalized to larger institutions.     

Aneurysm of the thoracic aorta. Review of 260 cases

In a 1980 review of the natural history and treatment of 176 thoracic aortic aneurysms, we noted the high incidence of rupture (47% overall) in 135 patients not treated surgically. Since that original study we have added another 84 patients to our series and have noted a complete change in management such that most patients are now treated surgically. We now have 260 patients in our series, 126 of whom were treated surgically. Sixty-seven were emergency operations and 59 were elective. Surgical mortality was 8% for elective resection and 33% for emergency operation. Over the past 5 years these figures have improved to 5% surgical mortality for elective resection and 16% surgical mortality for emergency resection. The 5 year survival rates for the entire series were 50% for patients treated with elective operation, 30% for combined emergency and elective operation groups, and 21% for nonsurgically treated patients. Abdominal aortic aneurysm was present in 74 patients (28%) and 23 of these patients had undergone a prior resection of an abdominal aortic aneurysm. This series documents the improved survival of patients with aneurysms of the thoracic aorta who are treated with prompt surgical intervention. It also further substantiates earlier findings of a high incidence of aneurysms of the abdominal aorta in this patient population.     

Ruptured abdominal aortic aneurysm: factors influencing operative mortality

Of fifty-eight consecutive patients surgically treated for aneurysm of the abdominal aorta, twenty were emergency cases following the rupture. Associated diseases were found in 85 per cent of patients; hypertension being the most common. Fifty per cent of patients were in shock on admission. The duration between rupture and operation was three hrs to two weeks with the average of 115.5 hrs. In six patients, the diagnosis of abdominal aortic aneurysm was known for over six months. The operative mortality rate in case of ruptured abdominal aortic aneurysm was 45 per cent. The most important determinants of survival were the incidence of shock on admission, the incidence of associated disease, the known duration of the aneurysm, and the time interval from rupture to admission. The intraoperative factors most influencing survival were the type of rupture, intraoperative hypotension, and total blood loss. Comparison of the mortality rate in elective surgery of abdominal aortic aneurysms (5.3 per cent) with that in ruptured aneurysms (45.0 per cent) suggests the necessity for early elective operations whenever abdominal aortic aneurysms are diagnosed.     

Abdominal aortic aneurysms. Risk factors and complications and their influence on indication for operation

From January 1982 to June 1986 475 patients underwent operation for abdominal aortic aneurysm (AAA) with reconstruction by tube graft or bifurcation graft. Patients were subdivided into 2 groups, those operated upon either electively or those operated upon urgently. The overall hospital mortality following elective intervention was 4.9%, following emergency intervention 36.5%. In patients operated upon electively preoperative risk factors such as history of myocardial infarction or coronary artery disease did not influence mortality. In patients operated upon urgently, however, the postoperative mortality was significantly higher (p less than 0.005) in those with a history of myocardial infarction or coronary artery disease. Postoperative morbidity in the emergency group (2.7 complications per patient) was significantly higher than in the elective group (0.94 complications per patient). These results show that early elective operation on asymptomatic aneurysms and younger patients with few risk factors can prevent rupture and reduce postoperative mortality to an acceptable level.     

Influence of presentation on outcome in abdominal aortic aneurysm repair.

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

The value of computed tomography in the management of symptomatic abdominal aortic aneurysms

The use of computed tomographic (CT) scanning in the diagnosis of ruptured abdominal aortic aneurysm is controversial because the delay created by the procedure, it has been argued, may increase overall mortality. However, if emergency surgery can be avoided in the medically compromised patient, surgical results may improve. To assess the value of CT scanning, we studied the 1983 to 1988 records of 65 hemodynamically stable patients with abdominal aortic aneurysms, who underwent diagnostic CT scanning for acute abdominal or back pain. Twenty-one patients had a history of severe cardiac, renal, or pulmonary disease. The average duration of the examination was 63 minutes; no episodes of hypotension occurred. Subsequently, 17 of 18 patients with ruptured aneurysms had emergency surgery, with 31% morbidity and 29% mortality. Of 44 patients found to have nonruptured aneurysms, 13 had other causes for their pain, nine were not considered surgical candidates, and 24 had elective aneurysmectomies, with 8% morbidity and 0% mortality. In three patients CT scanning excluded the diagnosis of aneurysm. Additional information provided by CT scanning enhanced the safety of the perioperative management of four patients with rupture and 14 without. In conclusion, the delay imposed by obtaining a preoperative CT scan in patients with possible ruptured aneurysm did not adversely affect patient outcome, and the information obtained from it aided significantly in both preoperative and intraoperative management.     

Ruptured abdominal aortic aneurysm: Factors influencing operative mortality

Of fifty-eight consecutive patients surgically treated for aneurysm of the abdominal aorta, twenty were emergency cases following the rupture. Associated diseases were found in 85 per cent of patients; hypertension being the most common. Fifty per cent of patients were in shock on admission. The duration between rupture and operation was three hrs to two weeks with the average of 115.5 hrs. In six patients, the diagnosis of abdominal aortic aneurysm was known for over six months. The operative mortality rate in case of ruptured abdominal aortic aneurysm was 45 per cent. The most important determinants of survival were the incidence of shock on admission, the incidence of associated disease, the known duration of the aneurysm, and the time interval from rupture to admission. The intraoperative factors most influencing survival were the type of rupture, intraoperative hypotension, and total blood loss. Comparison of the mortality rate in elective surgery of abdominal aortic aneurysms (5.3 per cent) with that in ruptured aneurysms (45.0 per cent) suggests the necessity for early elective operations whenever abdominal aortic aneurysms are diagnosed. Presented at the Fifteenth Annual Meeting of the Japanese Association for Cardiovascular Surgery, Kanazawa, Japan, May 17–18, 1985.     

The mortality of abdominal aortic aneurysm.

During a five year period 153 patients presented with abdominal aortic aneurysms and 135 received grafts. The mortality was 4.2% (3 of 71) for elective cases, 16.7% (2 of 12) for acute cases (the preoperative diagnosis of rupture found to be incorrect) and 55.8% (29 of 52) for patients with ruptured aneurysms. For patients with ruptured aneurysms there was a trend towards larger amounts of blood and colloid infusion in patients who died compared with those who survived, but there was no statistically significant difference either for the amount transfused, or for age, distance of referral, preoperative blood pressure, operating theatre time, or seniority of operating surgeon, between the two groups. It is possible that increased attention to cardiac and renal disease might reduce mortality following elective surgery. Measures to reduce the high mortality from ruptured aneurysm must be early detection and treatment of intact aneurysms, rapid diagnosis of rupture and expeditious surgery with minimal blood loss and the accurate exclusion of rupture in acute cases to achieve the same mortality as elective surgery.     

A study of the mortality from ruptured abdominal aortic aneurysms in a district community

In a 6-year period (1982-1987), 197 cases of ruptured abdominal aortic aneurysm were identified in the area covered by the Swindon Health District. Of these, 135 (69%) reached hospital alive, 88 (45%) were operated on, and only 28 (14%) survived. This represents an overall mortality of 86%. In comparison, the mortality from elective aneurysm repair for the same period was only 3.3%. These findings suggest that early detection of aortic aneurysms, leading to elective rather than emergency repair, would be of much greater benefit than the small increase in overall survival one would expect from improving treatment in cases of rupture.     

A retrospective study of ruptured abdominal aortic aneurysms--association with respiratory function and leukocytic granular elastase

Fifty-two cases of abdominal aortic aneurysms including common iliac aneurysms operated on during July, 1981 and December, 1989 have been studied. They were divided into the following three of elective operation (n = 34), impending rupture (n = 5), and ruptured (n = 13) groups. Cases with abdominal operations without aneurysms were randomly selected as the control group (n = 12). Overall operative mortality was 9.6%, consisted of 30.8% of the ruptured, 20.0% of the impending rupture and 0% of the elective operation groups. Respiratory functions including FEV1.0%, V75, V50, V25 and V25/Ht were significantly lowered in the ruptured group. PaO2 of the ruptured group was also significantly lowered in comparison with both the control and the elective operation groups. Leukocytic granular elastase, playing a role of destruction of the elastin component in the pulmonary alveoli and the aortic media, was increased in the patients with ruptured aortic aneurysms, though the difference was not significant. The data suggested the possibility of aneurysm rupture in case with elevated leukocytic granular elastase. Surgery for abdominal aortic aneurysm, even in cases with decreased pulmonary function, should be considered aggressively to elimination of ominous result of aneurysm rupture.     

Abdominal aortic aneurysm repair in the over eighties

Between January 1980 and September 1988, 34 octogenarians underwent aortic aneurysm repair. There were 26 men and eight women with a median age of 83 years (range 80-88 years). Twenty underwent 'emergency' repair after presenting with pain and/or collapse: 11 with a retroperitoneal rupture, three with an intraperitoneal rupture and six with an expanding aneurysm. The mortality rate for this group was 35 per cent. During the same period 14 patients had an elective repair and there were no deaths within 30 days. The mean hospital stay for the elective group was 14.2 days compared with 17.0 days for survivors in the emergency group. There was no significant difference in terms of risk factors between those who developed postoperative complications and those who did not. These mortality rates compare favourably with our overall mortality results for elective (4.6 per cent) and emergency (31 per cent) surgery. Those patients over 80 years of age with infrarenal abdominal aortic aneurysms should not be refused surgery on the basis of age alone; each patient should be judged individually.     

Abdominal aortic aneurysm in high-risk patients. Outcome of selective management based on size and expansion rate.

Low mortality rates for elective surgical treatment of abdominal aortic aneurysms justify an aggressive approach in most patients. However, in high-risk patients with small aneurysms and no symptoms, the decision to operate remains a delicate balance of risk and benefit. Our observations include 99 high-risk patients with asymptomatic abdominal aortic aneurysms initially measuring 3 to 6 cm in the largest transverse diameter, who have been followed 1 to 9 years (average 2.4 years) with serial echographic measurements. Elective operations were performed for aneurysmal enlargement greater than 6 cm or symptom development. An additional 11 patients with aneurysms initially greater than 6 cm, whose initial evaluation did not result in elective surgery, were also followed. Serial data documented a mean expansion rate of 0.4 cm/year for aneurysms smaller than 6 cm. Forty-one of these 99 high-risk patients with small aneurysms eventually underwent an elective resection with two deaths (4.9%). Thirty-four patients (34%) died from causes unrelated to their unoperated aneurysms, and 21 patients (21%) are alive without symptoms. Three of the 99 patients suffered aneurysm rupture and emergency operation with two deaths. Thus, of the 99 high-risk patients with small aneurysms, four have died of elective aneurysm surgery or rupture (4%). A protocol of re-echo (or computerized tomography) examination at 3-month intervals appears to define which of these high-risk patients require elective aneurysm surgery, and has limited rupture to less than 5%. Improved criteria may emerge from recent advances in high-resolution computerized tomography.     

The improving long-term outlook for patients over 70 years of age with abdominal aortic aneurysms.

During the past decade, selective criteria for elective surgery for abdominal aortic aneurysms have been refined based on natural history and aneurysm expansion information. Using these criteria, contemporary preoperative preparation and newer intraoperative technical adjuncts, 123 consecutive patients underwent elective resection with 1 death (mortality rate: 0.8%). These include all patients operated on with both elective and urgent aneurysms at this institution since 1978, with the exception of those with frank rupture. Most importantly, however, the 5-year life-table survival of all of these patients (average age: 71.3 years, range 46-96 yr) was 72%, including both hospital and late mortality rates. More than half of the patients were over 70 years old (78 cases), with no hospital deaths and a 5-year life-table survival probability of 67%. For those under 70 years of age at the time of operation, the 5-year life-table probability of survival was 79%. We believe that these accomplishments were a direct result of an aggressive policy of screening for and selectively treating coronary disease and carotid stenosis preoperatively and the utilization of such intraoperative adjuncts as routine Swan-Ganz monitoring, autologous blood transfusion, the cell saver, and the frequent use of the tube grafting (50%). Thus, with proper selection, the outlook for the patient over 70 years old with an elective abdominal aortic aneurysm resection now approaches that of the normal population (67% vs. 69%).     

Technical aspects in the management of abdominal aortic aneurysms

During the past decade, resection of abdominal aortic aneurysms has become common. The technical aspects of the operation are now relatively standardized and simplified. With concomitant improvements in anesthesia and intensive care, the operative mortality for elective resection of these aneurysms has declined progressively; several centres report an operative mortality of less than 5%. The author considers the following principles important in managing patients with abdominal aortic aneurysms: (a) simplicity and limited dissection are critical features of the operative technique; (b) tubular grafts should be used whenever possible; (c) selected patients should be transferred to the intensive care unit preoperatively for "fine-tuning" of the cardiovascular system; (d) patients should be monitored intraoperatively and postoperatively; (e) the surgeon should be aware of special problems such as horseshoe kidney, venous anomalies, adherent duodenum and the presence of major arteries arising from the aneurysm; (f) ruptured aneurysms should be diagnosed promptly and the patient operated upon without delay. Using these principles, the author's group achieved an operative mortality of only 1.8% in 168 patients with abdominal aortic aneurysms resected electively. However, the operative mortality for their patients with ruptured aortic aneurysms was 50%, a rate that has not changed appreciably over the years.     

INFRARENAL AORTIC ANEURYSM SURGERY IN A RURAL SURGICAL SERVICE: RISK FACTORS FOR MORTALITY

Background : An audit of both the emergency and elective abdominal aortic surgery that was performed in a rural surgical service, was carried out. Methods : Retrospective data analysis was performed on 41 patients who were treated for abdominal aortic aneurysms (AAA) during an 8-year period from 1989 to 1996. Postoperative outcomes were analysed with respect to patient age, mode of presentation (elective or emergency), transfusion requirements and pre-existing cardiac and respiratory disease. Univariate analysis was performed using Fisher's exact test, and the odds ratio for adverse outcome was calculated. Results : A postoperative mortality rate of 5.8% in elective repairs and 68% in cases of rupture was noted. Pre-existing respiratory disease, transfusion requirements of more than six units and presentation with retroperitoneal leak or rupture correlated with postoperative mortality, while age and pre-existing cardiac disease were shown not to be predictive of adverse outcome following surgery. Conclusions : An overall improvement in operative outcomes in the institution (Wimmera Base Hospital) that was audited would be affected by earlier referral for elective repair in selected patients. Like others, the authors believe that age on its own is not a contraindication to elective AAA repair.     

An evaluation of new methods of expressing aortic aneurysm size: relationship to rupture.

The diameter of aortic aneurysms were standardized to measures of patient size and normal aortic size in an effort to define indexes that might be more predictive of aneurysm rupture than raw aneurysm diameter alone. Normal aortic diameters were measured in 100 patients undergoing abdominal CT scans for other reasons, and an average infrarenal aortic diameter of 2.10 +/- 0.05 cm was observed. Normal aortic diameter was dependent on both age and sex, ranging from 1.71 +/- 0.06 cm in women below age 40 years to 2.85 +/- 0.04 cm in men above age 70 years. Overall, 11 (5.1%) of the ruptures occurred in aneurysms less than 5 cm in diameter, and four (1.9%) occurred in aneurysms less than 4.0 cm in diameter. When the CT scans of 100 patients undergoing elective aneurysm resection were compared with those of 36 patients with ruptured aneurysms, no threshold diameter value accurately discriminated between the two groups. However, standardization of the aneurysm diameter to the transverse diameter of the third lumbar vertebral body as an index of patient body size produced an accurate predictor of rupture when a threshold ratio of 1.0 was used. No aneurysm ruptured below this ratio, but 29% of elective aneurysms were smaller than the vertebral body diameter. Receiver operating characteristic curve analysis confirmed the superiority of the aneurysm to vertebral body diameter ratio as a discriminator of ruptured aneurysms. It appears that aneurysm diameter alone is not sufficiently predictive of rupture to be used as the sole indication for elective resection.     

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.)