How fast do very small abdominal aortic aneurysms grow?

Fifty patients with abdominal aortic aneurysms from 2.5 to 5.0 cm in anteroposterior diameter (median 3.1 cm, mean +/- S.E. 3.3 +/- 0.1 cm) were initially offered non-operative treatment. Two patients have subsequently undergone successful elective aneurysm resection because of increase in aneurysm size, and a third has died. The median annual growth rate of the aneurysm has been 0.22 cm and 77.8% increased in size between 6 monthly ultrasound examination. For aneurysms less than 4.0 cm the maximum 6 monthly increment in diameter was 0.7 cm. Even the smallest abdominal aortic aneurysms usually progressively increase in size and 6 monthly ultrasound remeasurement of aneurysm diameter is an essential component of non-operative management.     

Natural history of abdominal aortic aneurysm: A survey of 63 patients treated nonoperatively

During a 10-year period in which 735 patients presented with abdominal aortic aneurysms to our clinic, 63 were not offered operative treatment. The primary reason for choosing conservative treatment was concomitant diseases that increased the risk of operation. After 2 years of follow-up, half of the patients died, and the cumulative 5-year survival rate was 15%. Aneurysm rupture was the primary cause of death. The cumulative 5-year mortality hazard rate from rupture was 0.36, corresponding to an annual risk of rupture of 7%. The cumulative 5-year hazard rate of death from all other causes was 1.53, corresponding to an annual risk of 30%. Diameter of the aneurysm was found to be the only factor with a significant impact on the rate of rupture. The cumulative 5-year hazard rate of rupture among patients with aneurysms <6 cm and 6 cm was 0.2 and 0.6, respectively, corresponding to an annual risk of rupture of less than 5% and 10% to 15%, respectively. However, neither diameter nor other risk factors had significant influence on the time of rupture. In our opinion, once the diagnosis is confirmed the patient should be offered aneurysm resection if the general health status permits anesthesia.     

The selective management of small abdominal aortic aneurysms: the Kingston study.

The management of small abdominal aortic aneurysms less than 5.0 cm maximum diameter remains controversial particularly in patients who are medically fit. All patients referred with abdominal aortic aneurysms less than 5.0 cm maximum diameter were prospectively followed regardless of their fitness for operation. Two hundred sixty-eight patients had been entered into the study by December 31, 1988, and monitored until December 31, 1990, by at least two aneurysm sizings by ultrasonography, CT scanning, or both. The mean follow-up was 42 months. Operations were performed on 114 patients (if they were fit for operation) when the aneurysm reached 5.0 cm, expanded more than 0.5 cm in a 6-month period, or when the patient had significant occlusive disease requiring repair. In this group the mean annual increase in diameter was 0.9 cm. One hundred fifty-four patients were monitored without operation for a mean period of 42 months. One rupture occurred in this group. The average annual increase in diameter in the group not undergoing operation was 0.24 cm. This study supports a policy of observation for abdominal aortic aneurysms less than 5.0 cm in maximum diameter.     

Natural history of patients with abdominal aortic aneurysm

Factors determining the outcome for patients with abdominal aortic aneurysm (AAA) were analysed in a retrospective population-based study of 187 consecutively diagnosed AAAs at one hospital during a 9-year period. All aneurysms were diagnosed by ultrasound, and those cases that were not primarily operated upon, were followed by repeat ultrasound examinations. An expansion rate of more than 0.4 cm/year was seen in 27% of the aneurysms and a tendency towards a higher rate of expansion could be seen with larger lesions. The overall cumulative rupture rate was 12% at 5 years. For patients with small (less than 5 cm) aneurysms it was 2.5% at 7 years, and no aneurysm could definitively be shown to be smaller than 5 cm at the time of rupture. The rupture risk was significantly higher (28% at 3 years) for larger aneurysms (greater than or equal to 5 cm). The only reliable predictor for rupture was aneurysm size. The overall cumulative survival was 51% at 5 years. Patients with large aneurysms did not have a significantly shorter survival although a tendency for this to be the case was found. There was a significant difference between the proportion of deaths caused by aneurysm rupture in patients with small aneurysms when compared to those with large aneurysms, 5.5 and 53%, respectively. The expansion rate for AAA was highly individual and aneurysm diameter was the only recognisable predictor of rupture. The rupture rate for AAAs smaller than 5 cm was lower than previously reported.     

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.     

Endovascular treatment of abdominal aortic aneurysms

BACKGROUND: Endovascular treatment of abdominal aortic aneurysms is a rapidly evolving technique that has gained broad acceptance in the treatment of patients with abdominal aortic aneurysms. METHODS: A review of the English literature was done to determine the short- and long-term outcomes of endovascular repair of abdominal aortic aneurysms. Reports of complications such as endoleak, graft migration, graft limb occlusion, aneurysm rupture, and aneurysm enlargement were evaluated. RESULTS: Short-term results of endovascular repair of abdominal aortic aneurysms are excellent. The necessity for open conversions is less than 5%. The cumulative risk of aneurysm rupture is approximately 1% per year. The coverall incidence of graft limb occlusion was 2.8% in the follow-up period. The cumulative risk for a secondary procedure was 12% at 1 year, 24% at 2 years, and 35% at 3 years. Moderate and severe neck angulation was associated with an increased incidence of adverse events in the follow-up period. Endografts have the potential to become infected and develop aortoduodenal fistula. The treatment of ruptured aneurysms with endovascular grafts has been successful and a technique that is increasingly used. CONCLUSION: Endovascular treatment of abdominal aortic aneurysm is an effective technique with excellent short-term results. The long-term results remain to be determined. Ongoing surveillance is necessary to avoid late complications of aneurysm rupture.     

Probability of rupture of an abdominal aortic aneurysm after an unrelated operative procedure: a prospective study

It has been assumed by some authors that patients with abdominal aortic aneurysms may be at increased risk of rupture after unrelated operations. From July 1986 to December 1989, 33 patients (29 men, 4 women) with a known abdominal aortic aneurysm underwent 45 operations. Twenty-eight patients had an infrarenal abdominal aortic aneurysm, and five patients had a thoracoabdominal aneurysm. The abdominal aortic aneurysm ranged in transverse diameter from 3.0 to 8.5 cm (average 5.6 cm). Twenty-seven patients underwent a single operation, and six patients had two or more (range of 1 to 6). Operations performed were abdominal (13); cardiothoracic (9); head/neck (2); other vascular (11); urologic (7); amputation (2); breast (1). General anesthesia was used in 29 procedures, spinal/epidural in 6, and regional/local in 10. One postoperative death occurred from cardiopulmonary failure. One patient died of a ruptured abdominal aortic aneurysm at 20 days after coronary artery bypass (1/33 patients [3%]; 1/45 operations [2%]). Fourteen patients had repair of their abdominal aortic aneurysm at a later date, an average of 18 weeks after operation. Four patients had abdominal aortic aneurysm considered too small to warrant resection (average 3.6 cm). Four patients were considered at excessive risk for elective repair. The five thoracoabdominal aneurysm were not repaired. Four patients are awaiting repair. During this same 40-month period, two other patients, not known to have an abdominal aortic aneurysm, died of a ruptured abdominal aortic aneurysm after another operative procedure, at 21 days and 77 days. All three ruptured abdominal aortic aneurysms were 5.0 cm or greater in transverse diameter.(ABSTRACT TRUNCATED AT 250 WORDS)     

The natural history of abdominal aortic aneurysms and their risk of rupture

The UK 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 only 1%. We investigated baseline risk factors associated with aneurysm rupture in the 1090 trial patients and an additional 1167 patients enrolled in the UK Small Aneurysm Study. In this cohort of 2257 patients there were 103 cases of aneurysm rupture. After 3 years the annual rate of rupture was 2.2% (95% CI 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), 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. The most surprising finding was that women had a 3-fold higher risk of aneurysm rupture than men. Effective control of blood pressure and cessation of smoking are two simple measures that are likely to diminish the risk of aneurysm rupture and improve the cardiovascular health of patients with abdominal aortic aneurysm.     

True and anastomotic femoral artery aneurysms: is the risk of rupture and thrombosis related to the size of the aneurysms?

OBJECTIVE: the management of asymptomatic femoral aneurysms remains controversial. The purpose of this study was to investigate the relation between the diameter of true and anastomotic aneurysms and the risk of rupture. DESIGN: retrospective study. Material and methods: we reviewed the case records of 17 patients who underwent 17 arterial reconstructive procedures for true femoral aneurysms. In addition, the case records of 76 patients who underwent 90 arterial reconstructive procedures for femoral anastomotic aneurysms were identified and reviewed. RESULTS: the rupture rate for aneurysms less than 5 cm in diameter was 1.6% (one out of 64) compared with 16% (seven out of 43) for those larger than 5 cm. The thrombosis rate for aneurysms less than 5 cm in diameter was 17% compared with 5% for those larger than 5 cm. CONCLUSIONS: this study seems to show that the risk of rupture of femoral artery aneurysms is related to the diameter of the aneurysms. However, the rise in the risk of rupture with increasing size seems less dramatic than for abdominal aortic aneurysm (AAA).     

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.)     

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.     

Disparate outcome after endovascular treatment of small versus large abdominal aortic aneurysm

OBJECTIVES: The size of an abdominal aortic aneurysm is the most important parameter for determining whether repair is appropriate. This decision, however, must be considered in the context of long-term outcome of treatment, balancing risk for rupture with mortality from the initial procedure and all subsequent secondary procedures necessary when durability is not ideal. Information on the results of endovascular repair of small versus large aneurysms has not been available. METHODS: Preoperative imaging studies and postoperative outcome were assessed in 700 patients who underwent endovascular repair of abdominal aortic aneurysm over 6 years at a single institution. Patients were divided into two groups: 416 patients (59.4%) with aneurysms smaller than 5.5 cm in diameter and 284 patients (40.6%) with aneurysms 5.5 cm or larger in diameter. Outcome variables were assessed with the Kaplan-Meier method and the log-rank test. RESULTS: Patients with small and large aneurysms were comparable with regard to all baseline parameters assessed, with the single exception of a small increase in age (2.3 years) in patients with large aneurysms (P =.031). While there were no differences in rate of type II endoleaks, mid-term changes in sac diameter, or aneurysm rupture between the two groups, at 24 months patients with large aneurysms had more type I leaks (6.4% +/- 2.3% vs 1.4% +/- 0.6%; P =.011), device migration (13% +/- 4.0% vs 4.4% +/- 1.8%; P =.006), and conversion to open surgical repair (8.2% +/- 3.2% vs 1.4% +/- 1.1%; P =.031). Of greatest importance, at 24 months patient survival was diminished (71% +/- 4.6% vs 86% +/- 2.8%; P <.001) and risk for aneurysm-related death was increased (6.1% +/- 2.6% vs 1.5% +/- 1.0%; P =.011) in the group with large aneurysms. CONCLUSIONS: Outcome after endovascular repair of abdominal aortic aneurysm depends on size; results appear inferior in patients with larger aneurysms. These differences attain importance when choosing between observation and repair, balancing risk for rupture against size-dependent outcome.     

Are familial abdominal aortic aneurysms different?

A 9-year prospective study of 542 consecutive patients undergoing operation by one of the authors for abdominal aortic aneurysms was undertaken to define the incidence, clinical behavior, and anatomic characteristics of familial abdominal aortic aneurysms. Eighty-two (15.1%) patients having surgery for abdominal aortic aneurysms were found to have a first-degree relative with an aneurysm, as compared to nine (1.8%) of a control group of 500 patients of similar age and sex without aneurysmal disease (p less than 0.001). Detailed analysis was next performed of the pedigree charts of patients with a positive family history of aneurysm who underwent repair of abdominal aortic aneurysms by all authors over the 9-year study period. This review identified a total study population of 86 families with 209 first-degree relatives with abdominal aortic aneurysms. Clinical and anatomic features of this familial group were compared to those of 460 patients operated on for abdominal aortic aneurysms who had no family history of abdominal aortic aneurysms. Patients with familial abdominal aortic aneurysms were more likely to be women (35% vs 14%), and men with familial abdominal aortic aneurysms tended to be about 5 years younger than the women. There was no significant difference between the patients with nonfamilial and familial abdominal aortic aneurysms in anatomic extent of aneurysmal disease, multiplicity of aneurysms, associated occlusive disease, or blood type. There was a history of aneurysm rupture in 35 of 86 (40.7%) families with familial abdominal aortic aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endovascular repair or surveillance of patients with small AAA.

OBJECTIVE: To compare the outcome of patients with small abdominal aortic aneurysms (AAA) treated in a prospective trial of endovascular aneurysm repair (EVAR) to patients randomized to the surveillance arm of the UK Small Aneurysm Trial. METHOD: All patients with small AAA (< or = 5.5 cm diameter) treated with a stent graft (EVARsmall) in the multicenter AneuRx clinical trial from 1997 to 1999 were reviewed with follow up through 2003. A subgroup of patients (EVARmatch) who met the age (60-76 years) and aneurysm size (4.0-5.5 cm diameter) inclusion criteria of the UK Small Aneurysm Trial were compared to the published results of the surveillance patient cohort (UKsurveil) of the UK Small Aneurysm Trial (NEJM 346:1445, 2002). Endpoints of comparison were aneurysm rupture, fatal aneurysm rupture, operative mortality, aneurysm related death and overall mortality. The total patient years of follow-up for EVAR patients was 1369 years and for UK patients was 3048 years. Statistical comparisons of EVARmatch and UKsurveil patients were made for rates per 100 patient years of follow up (/100 years) to adjust for differences in follow-up time. RESULTS: The EVARsmall group of 478 patients comprised 40% of the total number of patients treated during the course of the AneuRx clinical trial. The EVARmatch group of 312 patients excluded 151 patients for age < 60 or > 76 years and 15 patients for AAA diameter < 4 cm. With the exception of age, there were no significant differences between EVARsmall and EVARmatch in pre-operative factors or post-operative outcomes. In comparison to the UKsurveil group of 527 patients, the EVARmatch group was slightly older (70 +/- 4 vs. 69 +/- 4 years, p = 0.009), had larger aneurysms (5.0 +/- 0.3 vs. 4.6 +/- 0.4 cm, p < 0.001), fewer women (7 vs. 18%, p < 0.001), and had a higher prevalence of diabetes and hypertension and a lower prevalence of smoking at baseline. Ruptures occurred in 1.6% of EVARmatch patients and 5.1% of UKsurveil patients; this difference was not significant when adjusted for the difference in length of follow up. Fatal aneurysm rupture rate, adjusted for follow up time, was four times higher in UKsurveil (0.8/100 patient years) than in EVARmatch (0.2/100 patient years, p < 0.001); this difference remained significant when adjusted for difference in gender mix. Elective operative mortality rate was significantly lower in EVARmatch (1.9%) than in UKsurveil (5.9%, p < 0.01). Aneurysm-related death rate was two times higher in UKsurveil (1.6/100 patient years) than in EVARmatch (0.8/100 patient years, p = 0.03). All-cause mortality rate was significantly higher in UKsurveil (8.3/100 patient years) than in EVARmatch (6.4/100 patient years, p = 0.02). CONCLUSIONS: It appears that endovascular repair of small abdominal aortic aneurysms (4.0-5.5 cm) significantly reduces the risk of fatal aneurysm rupture and aneurysm-related death and improves overall patient survival compared to an ultrasound surveillance strategy with selective open surgical repair.     

Ruptured aneurysm of the descending thoracic and thoracoabdominal aorta. Analysis according to size and treatment.

Acute rupture was confirmed at operation in 117 patients treated for descending thoracic or thoracoabdominal aortic aneurysm. Descending thoracic (n = 80) aortic rupture occurred into lung or esophagus in 8, the pleural cavity in 49, and the mediastinum in 23. Upper abdominal aortic (n = 37) rupture occurred into peritoneal cavity in 3 and into retroperitoneal tissues in 34. Aneurysmal size (range, 5 to 17 cm; median, 8 cm) could be determined retrospectively in 86 patients; 59 (74%) descending thoracic and 27 (73%) abdominal aorta. Size (external diameter) in the former was 8 (14%), 5 to 6 cm; 21 (36%), 6 to 8 cm; 23 (39%), 8 to 10 cm; and 7 (12%) greater than 10 cm. Size at the abdominal site was similar. Thus size was not greater than 10 cm in 52 (88%) (range, 5 to 10 cm), which contradicts opinions that thoracic aneurysms rupture only when size exceeds 10 cm. Twenty-nine patients (25%) were hypotensive (systolic blood pressure less than 100 mmHg), of whom 16 (55%) had cardiac arrest before operation. Associated conditions included advanced age (greater than or equal to 75 years) in 26 (22%), coronary artery disease in 41 (35%), chronic obstructive pulmonary disease in 46 (39%), renal insufficiency in 25 (21%), and cardiovascular disease in 22 (18%). The overall early survival rate (30-day) was 89 of 117 patients (76%); 69% in patients with hypotension, 56% of patients with cardiac arrest, 88% in good-risk patients. Five-year (Kaplan-Meier) survival was 28%. Because elective operation is associated with 92% survival, this should be considered before rupture when aneurysm is 5 cm or larger in good-risk patients, in patients with symptomatic aneurysms, and in most patients with larger aneurysms.     

Prevalence of abdominal aortic aneurysm in patients with occlusive peripheral vascular disease

Over a 1-year period, 242 patients with peripheral vascular disease underwent abdominal ultrasonography to detect the presence of an abdominal aortic aneurysm. In 34 (14 per cent) an abdominal aortic aneurysm was found; half of these aneurysms were greater than 4 cm in diameter. In addition, 16 patients had ectatic aortas. Abdominal aortic aneurysms were more common in men than in women (17 versus 8 per cent). Patients with claudication were as likely to have an abdominal aortic aneurysm as those with rest pain or gangrene. The presence of aortoiliac occlusive disease increased the chance of an aneurysm being present (P less than 0.02). Patients with occlusive peripheral vascular disease are a high-risk group with regard to the development of an abdominal aortic aneurysm. Patients with proximal occlusive disease represent a subgroup at even higher risk.     

Late iliac artery aneurysms and occlusive disease after aortic tube grafts for abdominal aortic aneurysm repair. A 35-year experience.

Controversy continues over whether patients treated with straight Dacron aortic tube grafts for an abdominal aortic aneurysm remain at significant risk for subsequent development of iliac aneurysm or occlusive disease. To address this issue, the authors performed a population-based analysis of 432 patients who had an abdominal aortic aneurysm diagnosed between 1951 and 1984. Aneurysm repair was performed eventually in 206 patients (48%). To ascertain differences in late development of graft-related complications, iliac aneurysms, and arterial occlusions, the authors compared all tube-graft patients with similar numbers of bifurcated-graft patients matched for age and year of operation. In the tube-graft group, no subsequent clinically evident or autopsy-proven iliac aneurysms or iliac occlusive disease were noted. Over a mean follow-up of 6 years (range, 4 to 18 years), new aortic aneurysms occurred in the proximal aorta in both tube and bifurcated-graft patients (5.0% and 2.5%, respectively). In contrast the cumulative incidence of graft-related complications was higher with a bifurcated prosthesis (12.8%) compared with a straight graft (5.0%) (p = 0.15). These problems generally occurred 5 to 15 years postoperatively and emphasize the need for long-term graft surveillance. The authors conclude that straight tube-grafts for repair of abdominal aortic aneurysms provide excellent late patency with minimal risk of subsequent iliac aneurysm development.     

Determination of the expansion rate and incidence of rupture of abdominal aortic aneurysms

Expansion rate and incidence of rupture of abdominal aortic aneurysms in relation to their size is a source of debate. We studied 114 patients (out of a cohort of 752 consecutive patients admitted with abdominal aortic aneurysms) who were denied any immediate operation because of patient's refusal, high surgical risk, or small transverse diameter as assessed by CT scanning and ultrasonography. All patients not operated on underwent from two to six repeated examinations during an average follow-up period of 26.8 months (range, 3 to 132). Forty-seven patients (41.2%) were subsequently operated on electively because of marked increase of transverse diameter of the aneurysm (n = 44) or for other reasons (n = 3), with a death rate of 0%. Eighteen other patients underwent emergency operation for leaking or ruptured aneurysms, and there were five deaths. The incidence of rupture was clearly related to the final diameter value, rising from 0% in aneurysms less than 40 mm to 22% in large size aneurysms (greater than or equal to 50 mm). Among the 49 patients not operated on, one died of rupture before operation and five of causes unrelated to the disease. Using individual serial measurements, we determined the linear expansion rate of the aneurysm, which proved to be related to initial diameter values: 5.3 mm/year for diameters less than 40 mm (n = 49), 6.9 mm/year in the 40 to 49 mm group (n = 41), and 7.4 mm/year for diameters of 50 mm or more (n = 24).(ABSTRACT TRUNCATED AT 250 WORDS)     

Late results of small untreated abdominal aortic aneurysms

We report our experience with 73 patients who were initially selected for nonoperative management of an abdominal aortic aneurysm less than 5 cm in diameter. Size of the aneurysm was determined by ultrasound (34); arteriography (16); computerized tomography (17); plain x-ray (4); and magnetic resonance imaging (2). End points of the study were subsequent elective resection, rupture, death from cause other than rupture, or an intact aneurysm followed for a minimum of three years. Overall, 28 (38%) aneurysms were subsequently resected on an elective basis; four (5%) ruptured; 15 (21%) were intact at the time of the patient's death; and 26 (36%) remained intact during follow-up of 3 to 6.5 years. Indications for elective resection were aneurysm enlargement (21); symptoms suggesting impending rupture (3); and improvement in medical condition (4). In the 43 aneurysms initially less than 4 cm diameter, 16 (37%) had elective resection and one (2%) ruptured, and in the 30 that were 4–4.9 cm, 12 (40%) were resected and three (10%) ruptured. The four aneurysms that ruptured had enlarged to greater than 5 cm prior to rupture. We conclude that aneurysms less than 4 cm can be safely followed. Aneurysms 4–4.9 cm should be considered for operation, depending upon the size of the aneurysm, patient's life expectancy, and risk factors for surgery. Any aneurysm that enlarges should be resected, especially if the aneurysm becomes larger than 5 cm in diameter.Presented at the Annual Meeting of the Southern California Vascular Surgical Society, September 21–23, 1990.     

Smoking, Lung Function and the Prognosis of Abdominal Aortic Aneurysm

Background the UK Small Aneurysm Trial was established to test the benefit of prophylactic elective surgery for small abdominal aortic aneurysms (4.0–5.5 cm in diameter) and identify prognostic risk factors, including smoking. Patients, methods and outcomes one thousand and ninety patients (902 men and 188 women, mean age 69.3 years) were randomised to either early elective surgery or ultrasonography surveillance until the aneurysm diameter exceeded 5.5 cm, mean follow-up was 4.6 years. Baseline assessments included lung function tests and cotinine (a smoking marker). The principal outcome measures were all-cause mortality and aneurysm rupture. Results during the course of the trial, aneurysm rupture was diagnosed in 25 patients and 309 patients died. Whereas self-reported smoking status was not significantly associated with survival, patients without any trace of plasma cotinine had a significantly improved long-term (6-year) survival,p =0.02. Current smokers had a lower FEV₁than past- and never-smokers. FEV₁was the most powerful predictor of long-term (6-year) survival, the crude death rates per 100 person-years were 9.1, 6.9 and 4.6 for those with FEV₁<1.9 l, 1.9–2.5 l and >2.5 l respectively, p=0.001. Moreover, the rupture rate was 1.9% per year for patients positive for plasma cotinine compared with 0.5% in those without trace of plasma cotinine,p =0.004. Conclusions self-reported smoking status underestimates the effect of continued smoking on the prognosis of patients with small abdominal aortic aneurysm. Patients with high plasma cotinine concentrations (smokers) have an increased risk of aneurysm rupture and poorer long-term survival.