Surgical treatment of aneurysms of the abdominal and thoracic aorta

The danger of an arteriosclerotic abdominal aortic aneurysm is clearly related to the size of the aneurysm. From available clinical data it seems logical to recommend elective surgical excision and graft replacement of abdominal aneurysms 6 cm or greater in diameter because of the considerable danger of rupture of untreated aneurysms of this size. Although small aortic aneurysms do rupture, most patients with small abdominal aneurysms may be safely followed with examination at regular intervals. Surgery is reserved for those who demonstrate evidence of aneurysm expansion. The operative mortality rate for elective surgical excision of abdominal aortic aneurysms is by no means negligible but has probably diminished recently to levels of approximately 5% in the hands of experienced surgeons. Achievement of an operative mortality rate in this range requires sensible case selection, expeditious operative management and skillful postoperative care with particular attention to problems of hypoxemia in the early postoperative period.Patients with ruptured abdominal aortic aneurysms require immediate aneurysm resection for survival. Of those patients with ruptured abdominal aneurysms who reach the hospital alive, approximately 60% should be salvaged at present by emergency surgery.The prognosis of the patient with a thoracic aortic aneurysm depends upon the etiology of the aneurysm. Syphilitic aneurysms of the thoracic aorta are now fortunately rare but appear to have a high incidence of rupture. The prognosis of patients with arteriosclerotic aneurysms, which characteristically involve the descending thoracic aorta, appears to be considerably better than that of patients with aneurysms of the abdominal aorta for unknown reasons. Since the removal of thoracic aneurysms ordinarily requires extracorporeal bypass and is associated with an operative mortality rate in the range of 20%, considerable judgment must be exercised in case selection for elective resection of such aneurysms.The surgery of dissecting aneurysms of the thoracic aorta has recently been modified by the widespread acceptance of antihypertensive drug therapy for acute dissection. Surgery may be reserved, hopefully on an elective basis, for those patients with significant aortic valvular insufficiency, significant aneurysmal dilatation of the dissected aorta, or symptomatic involvement of a major aortic branch in the dissection.     

Hemodynamic influence of peripheral vascular occlusive disease on abdominal aortic aneurysms.

AIM: Clinical evidence indicates that hemodynamic conditions such as peripheral vascular occlusive disease (PVOD) influence abdominal aortic aneurysm (AAA) disease. METHODS: We retrospectively analyzed 406 operated cases of AAA at our institute over the last 15 years, and compared 39 patients with PVOD to those without, to examine hemodynamic effects and risk factors. Aneurysm size at operation, rupture, shape, expansion rate and several preoperative risk factors were compared. RESULTS: Mean aortic diameter in the AAA with PVOD patients (56.8+/-17.8 mm) showed no significant difference to that in the AAA without PVOD group (60.4+/-14.8 mm). However, the subgroup of AAA with PVOD in whom the aneurysm was found prior to PVOD diagnosis (67.8+/-18.1 mm) (n=19) showed a larger mean AAA diameter compared to the AAA (not followed up until operative indication/prior to operation) without PVOD group (60.4+/-14.8 mm), (n=340), (p=0.04). Smoking was the only preoperative risk factor to show a difference between AAA patients with and without PVOD. The aneurysm expansion rate was determined retrospectively in 13 patients with PVOD who had been followed for at least 1 year by CT scan and 17 patients without PVOD. The rate in the PVOD group was 8.1 mm/year, which was significantly faster than that in PVOD-free patients (4.6 mm/year), (p=0.03). CONCLUSIONS: The findings of a large diameter and fast expansion rate in AAA patients with concomitant PVOD suggest that the hemodynamic effects of PVOD have a great influence on AAA development.     

Clinical and patho-anatomical factors affecting expansion of thoracic aortic aneurysms

OBJECTIVE—To examine the expansion of aneurysmal aortic segments ( 35 mm) and to assess the impact of clinical and patho-anatomical factors on aneurysm expansion.
DESIGN—87 consecutive patients (mean age 63.6 years, range 22-84 years) were studied using serial (six month intervals) computed tomographic or magnetic resonance imaging to monitor progression of thoracic aortic aneurysms. Aortic diameter was measured at seven predetermined segments and at the site of maximum aortic dilatation (MAX).
RESULTS—780 segment intervals were identified. The median overall aneurysm expansion rate was 1.43 mm/year. This increased exponentially with incremental aortic diameter (p < 0.01) and varied by anatomical segment (p < 0.05). The presence of intraluminal thrombus (p < 0.01) but not dissection or calcification was associated with accelerated growth. Univariate analysis identified thrombus (p < 0.001), previous stroke (p < 0.002), smoking (p < 0.01), and peripheral vascular disease (p < 0.05) as factors associated with accelerated growth in MAX. Dissection, wall calcification, and history of hypertension did not affect expansion. β Blocker treatment was not associated with protection. Multivariate analysis confirmed the positive effect of intraluminal thrombus and previous cerebral ischaemia, and the negative effect of previous aortic surgery on aneurysm growth. These findings translated into a mathematical equation describing exponential aneurysm expansion.
CONCLUSIONS—Aneurysmal thoracic aortic segments expand exponentially according to their initial size and their anatomical position within the aorta. The presence of intraluminal thrombus, atherosclerosis, and smoking history is associated with accelerated growth and may identify a high risk patient group for close surveillance.


Keywords: thoracic aortic aneurysm; expansion rate     

Ultrafast computed tomography in the diagnosis of aortic aneurysms and dissections

UFCT, by virtue of its 50 to 400 millisecond acquisition times, 0.75 to 1.5 mm resolution, and excellent vascular opacification, provides a rapid, minimally invasive method for assessing aortic aneurysms and dissections. During a 3.5-year period, 50 patients with suspected thoracic, thoracoabdominal, and abdominal aortic aneurysms or dissections were evaluated using the Imatron C-100 UFCT scanner. Eighteen patients had thoracic or thoracoabdominal aneurysms. 17 had thoracic or thoracoabdominal dissections, 7 had abdominal aneurysms, and in 8 no aneurysms or dissections were found. In 23 of the 35 patients with thoracic or thoracoabdominal aneurysms or dissections, the UFCT findings accurately reflected the findings at aortography, surgery, or autopsy. There was one false-positive examination. The remaining 11 patients with UFCT findings of aneurysm or dissection were followed clinically. In the 7 patients with abdominal aneurysms, 4 were confirmed by angiography or surgery, and 3 were followed clinically. Of the 8 patients with negative UFCT examinations, 2 had subsequent angiography that failed to show an aneurysm, and 6 were followed from 6 to 30 months without developing findings suggestive of aneurysm. UFCT appears to be a useful, minimally invasive technique for detecting and following aortic aneurysms and dissections.     

Change in aneurysm diameter after stent-graft repair of ruptured abdominal aortic aneurysms.

PURPOSE: To compare the changes in aneurysm size following endovascular aneurysm repair (EVAR) for ruptured versus elective abdominal aortic aneurysms (AAA). METHODS: Aneurysm sac diameter was measured from computed tomographic (CT) scans in 14 hemodynamically stable patients (14 men; mean age 74+/-7 years, range 60 to 83) prior to emergent stent-graft repair for ruptured AAA. The aneurysm diameter change was followed postprocedurally with serial CT and the outcomes compared to 74 AAA patients (58 men; mean age 74+/-7 years, range 56 to 87) having elective EVAR in the same time period. The mean rate of sac decrease (mm/month) was calculated for each group. RESULTS: There were 3 postoperative deaths in the ruptured AAA cohort, leaving 11 patients available for follow-up analysis (mean 16 months, range 2-49). Eight (73%) patients with ruptured AAA demonstrated significantly decreased (>5 mm) aneurysm diameters compared with 32 (43%) elective cases (p=0.07) followed a mean 20 months (range 3-51). The mean rate of sac diameter decrease was 1.50+/-1.03 mm/month in the rupture group versus 0.73+/-0.86 mm/month in the elective group (p=0.04). CONCLUSIONS: This study suggests that ruptured AAAs treated with stent-graft experience sac regression at a higher rate compared with electively treated AAA. The reasons for these findings remain unclear.     

Predictive value of conventional computed tomography in determining proximal extent of abdominal aortic aneurysms and possibility of infrarenal clamping

The present study aimed to evaluate the diagnostic reliability of computed tomography in determining the proximal extent of abdominal aortic aneurysms and the possibility of infrarenal clamping. Preoperative computed tomographic findings, together with the operative data for 95 patients, were retrospectively analyzed in light of the operative findings. Eighty-nine (93.68%) of the patients were men and 6 (6.32%) were women, with a mean age of 66.27 +/- 18.14 years. Diagnosis of infrarenal aneurysm by computed tomography was confirmed at the time of surgery in 91 (95.79%) of 95patients. The negative-predictive value of computed tomography in detecting supra-aneurysmal renal arteries was found to be 95.79%. The specificity was 98.91%. Infrarenal cross-clamping was performed in 59 (62.11%) of 95 patients, whose aortic segments between the renal artery orifices and the proximal borders of the aneurysms had a mean length of 26.4 +/- 7.11 mm by computed tomography Suprarenal clamping was required in 36 (37.89%) of the 95 patients, whose aortic segments had a mean length of 12.7 +/- 3.48 mm. We conclude that conventional computed tomography is reasonably accurate in determining the proximal extent of abdominal aortic aneurysms. Although there is a high rate of error in determining the possibility of infrarenal clamping when no specific measurements are taken, infrarenal clamping can be planned when measurement by computed tomography shows a length of > or = 26 mm between the renal arteries and the proximal extent of the aneurysm. In patients with shorter aortic segments, suprarenal aortic clamping should be considered.     

Unoperated thoracic aortic aneurysms: survival rates of the patients and determinants of prognosis.

The purpose of this study was to evaluate the long-term prognosis of unoperated thoracic aortic aneurysms, and to detect the risk factors which determine the prognosis of unoperated patients. The subjects were 52 unoperated patients with 58 thoracic aortic aneurysms (22 of the ascending aorta, 36 of the descending aorta or the aortic arch) and 38 with abdominal aortic aneurysms. The survival rates of the patients with ascending aortic aneurysms at 3 years and 5 years and those of the patients with descending aortic aneurysms at 5 years were significantly higher than those of the patients with abdominal aortic aneurysms. The risk factors for rupture of thoracic aortic aneurysms were the large size of aneurysms and non-management by the cardiologist and the risk factors for death unrelated to the aneurysms were patient age, male gender and non-management by the cardiologist.     

Modern trends in the management of aortic aneurysms. Review of 450 cases experienced

Treatment of various aortic aneurysms in 450 cases experienced during the past 25 years was analysed. One hundred and five patients were treated with survival rate of 80.2% in the thoracic aortic aneurysm group, 65 patients with survival rate of 76.9% in the dissected aneurysm of the aorta group, 175 patients with survival rate of 93.1% in the nonruptured abdominal aortic aneurysm group and 37 patients with survival rate of 75.7% in the ruptured abdominal aortic aneurysm group. From 1981 to the present time, considerable improvement of the operative results has been achieved with refinement of cardiovascular adjunctive techniques and operative procedures with careful management of the patients. Survival rates are now reached to 88.7% in the thoracic aortic aneurysm, 81.0% in the dissected aneurysm, 100% in the nonruptured abdominal aortic aneurysm and 81.2% in the ruptured abdominal aortic aneurysm. From the careful analyses of the results, prompt diagnosis, distinct treatment policy, strict operative indication and better surgical procedure are considered to have contributed to these excellent operative results.     

A comparative study of iliac and abdominal aortic aneurysms.

BACKGROUND: The aim of the paper is to compare the epidemiology, risk factors and manifestations of iliac and abdominal aortic aneurysms. METHODS: Two studies were used: 1. 5,470 65-73-year-old men invited for screening for abdominal aortic aneurysms. 2. Review of all 350 patients operated on for central aneurysms in the county of Viborg, Denmark from 1989-1997. RESULTS: 4,176 attended for screening. One hundred and seventy (4.0%) had an abdominal aortic aneurysm. Twenty-one (0.56%) needed operation. The proportion of patients with common iliac aneurysms requiring surgery was 0.17%. The operative incidence of iliac aneurysm was 18.4 per million per year, and 92.4 per million per year were operated on for abdominal aortic aneurysm. The mean serum cholesterol level for isolated iliac aneurysm and combined aneurysms was significantly lower compared to isolated abdominal aortic aneurysm (p<0.05). Urological symptoms were present in 42% of cases with isolated iliac aneurysm, and 25% of combined aneurysms compared to 8% of isolated abdominal aortic aneurysms. Fifty-eight percent of the isolated iliac aneurysms were ruptured, as against 27% of the abdominal aortic aneurysms. The peri- and postoperative mortality was 57% in ruptured isolated iliac aneurysms, 47% in ruptured combined aneurysms, and 31% in ruptured isolated aortic aneurysms. CONCLUSIONS: Iliac aneurysms seem to be more underdiagnosed than abdominal aortic aneurysms, and are often diagnosed because of clinical manifestations, especially urological, or rupture. Iliac aneurysms seem more lethal than those of the abdominal aorta in cases of rupture.     

Cardiovascular disease and mortality in older adults with small abdominal aortic aneurysms detected by ultrasonography: the cardiovascular health study

BACKGROUND: Persons with abdominal aortic aneurysm are more likely to have a higher prevalence of risk factors for and clinical manifestations of cardiovascular disease. It is unknown whether these factors explain the high mortality rate associated with abdominal aortic aneurysm. OBJECTIVE: To describe the risk for mortality, cardiovascular mortality, and cardiovascular morbidity in persons screened for abdominal aortic aneurysm. DESIGN: Longitudinal cohort study. SETTING: Four communities in the United States. PARTICIPANTS: 4734 men and women older than 65 years of age recruited from Medicare eligibility lists. MEASUREMENTS: Abdominal ultrasonography was used to measure the aortic diameter and the ratio of infrarenal to suprarenal measurement of aortic diameter in 1992-1993. Abdominal aortic aneurysm was defined as aortic diameter of 3 cm or greater or infrarenal-to-suprarenal ratio of 1.2 or greater. Mortality, cardiovascular disease mortality, incident cardiovascular disease, and repair or rupture were assessed after 4.5 years. RESULTS: The prevalence of aneurysm was 8.8%, and 87.7% of aneurysms were 3.5 cm or less in diameter. Rates of total mortality (65.1 vs. 32.8 per 1000 person-years), cardiovascular mortality (34.3 vs. 13.8 per 1000 person-years), and incident cardiovascular disease (47.3 vs. 31.0 per 1000 person-years) were higher in participants with aneurysm than in those without aneurysm; after adjustment for age, risk factors, and presence of other cardiovascular disease, the respective relative risks were 1.32, 1.36, and 1.57. Rates of repair and rupture were low. CONCLUSIONS: Rates of total mortality, cardiovascular disease mortality, and incident cardiovascular disease were higher in participants with abdominal aortic aneurysm than in those without aneurysm, independent of age, sex, other clinical cardiovascular disease, and extent of atherosclerosis detected by noninvasive testing. Persons with smaller aneurysms detected by ultrasonography should be advised to modify risk factors for cardiovascular disease while under surveillance for increase in the size of the aneurysm.     

Multiple HIV-related aneurysms: open and endovascular treatment.

PURPOSE: To report successful endovascular repair of thoracic aortic aneurysms in 2 patients with human immunodeficiency virus (HIV). CASE REPORTS: Thoracic and abdominal aortic aneurysms (AAA) were found in a 60-year-old woman 1 year after she was diagnosed with HIV. Because of pain and risk of rupture, the AAA was repaired with conventional open techniques in February 1997, while the thoracic aneurysm was excluded in a staged procedure using a homemade endograft delivered through a 10-mm conduit sewn to the aortic tube graft. Two months later, new aneurysms were found in the superficial femoral arteries bilaterally; both were excised and replaced with vein grafts. After 7 years, the patient is well and no longer takes antiretroviral medication. Surveillance imaging shows continued patency of the stent-graft without evidence of leak or migration. In a more contemporary case, a 46-year-old man was found to have 5 focal aneurysms in the aorta; the most proximal descending thoracic aneurysm increased 2 cm in 2 weeks. The two thoracic aneurysms were successfully excluded using 2 Excluder stent-grafts. At 7 months, he was doing well, and the aneurysm had shrunk 11 mm. CONCLUSIONS: Endovascular and open treatment of HIV-related aneurysms is possible, with excellent long-term results. Patients with long-life expectancy should be treated according to the same guidelines as patients without HIV.     

Multiple endovascular stent-graft implantations in a patient with aortic thoracic and abdominal aneurysms due Takayasu arteritis

We report an adult female patient with Takayasu arteritis (TA) receiving conventional medical treatment and anti-TNF therapy, which developed progressive thoracic and abdominal aortic aneurysms. She developed imminent rupture of the thoracic aneurysm and an endovascular stent-graft (EVSG) was emergency implanted and a year after this procedure the abdominal aneurysm increased in size requiring reoperation and placement of another EVSG. Both procedures had a very good outcome. This case shows the effectivity and security of multiple EVSG implantations in multiple aortic aneurisms in patients with TA.     

Surgical and medical treatments of true and dissecting aortic aneurysm in cases over 65 years old

Ninety-one patients with true and dissecting aortic aneurysm were reviewed. They ranged in age from 65 to 87 years (mean 71 years). Forty-eight patients were diagnosed with abdominal aortic aneurysm, 21 patients with thoracic aortic aneurysm and 22 patients with dissecting aortic aneurysm. They were divided into 2 categories, surgical group and non-surgical, and the prognoses of the 2 groups were compared. The average age of surgically treated cases was significantly younger than that of non-surgical cases. This study suggests that elective operation should be considered for abdominal aortic aneurysms because of the high risk of late rupture. In older patients with thoracic aortic aneurysm, the prognosis was better in surgically treated patients than in those not treated. However, the surgical mortality rate of elective operation was high. The surgical mortality rate of older patients with dissecting aortic aneurysm was not satisfactory, and medical treatment which decreases blood pressure should be considered first. All patients classified as Stanford type A should be operated on if possible.     

National Adherence to Medical Management of Aortic Aneurysms

ObjectivesThe purpose of this study was to describe levels of adherence to guideline-based medical management in patients with aortic aneurysms, using an analogous population with coronary artery disease as a comparator. Adherence among those with aortic aneurysms has never been studied.MethodsAdult patients with an aortic aneurysm or coronary artery disease diagnosed between 2004 and 2018 in the Optum Clinformatics deidentified Datamart were queried. Aneurysms were subclassified as thoracic, abdominal, or both. Receipt of an antihypertensive or antihyperlipidemic was determined through pharmacy claims. Adherence was determined as receipt of the indicated pharmacologic(s) after a diagnosis of aneurysm or coronary artery disease. Adherence was compared between those with aneurysms and coronary disease using univariable logistic regression.ResultsAfter exclusions, 194,144 patients with an aortic aneurysm and 3,946,782 with coronary artery disease were identified. Overall adherence was low (45.0%) and differed significantly by aneurysm subtype: highest in isolated thoracic (45.9%) and lowest in isolated abdominal aneurysms (42.6%). Adherence levels declined significantly after 1 year by about 15% in each aneurysm subtype. All subtypes of aneurysm had a significantly lower odds of adherence compared to those with coronary disease with odds ranging from 0.61 in those with isolated abdominal aneurysms to 0.80 with isolated thoracic aneurysms.ConclusionsAdherence among those with aortic aneurysms is very low, differs by subtype, and declines with time. Levels of adherence in those with aortic aneurysms is significantly lower compared to those with coronary artery disease. This should prove a reasonable target for implementation initiatives.     

The characteristics of screened patients with abdominal aortic aneurysm.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) has not yet been established in Japan. We therefore report the characteristics of a screened population and discuss the implications of screening using ultrasound in Japan. METHODS: The subjects in our screening group were composed of 4428 participants who were 60 years of age or older. Aneurysm was detected in 16 cases, 15 males and 1 female, the detection rate being 0.4% in total and 0.9% in the males. We compare the characteristics of screened patients (n = 16) with non-screened patients operated on for abdominal aortic aneurysm (n = 166). RESULTS: There were no significant differences in the mean age or in the female ratio between the screened and non-screened groups (71 vs 70 y/o, 6% vs 13%, respectively). Solitary iliac aneurysms were significantly (p < 0.05) more frequent in the screened than in the non-screened group (19% vs 3%). The size of aneurysm in the screened group was significantly (p < 0.05) smaller compared with the non-screened group. Sixty-three per cent of the screened group and only 8% of the non-screened group had an aneurysm less than 40 mm in size. Aneurysm was palpable in only 31% of those of the screened group. There were no significant differences between the groups in the frequency of arteriosclerotic risk factors such as hypertension, ischaemic heart disease, diabetes mellitus, peripheral vascular disease and smoking habits. Surgical treatment was selected in 7 out of 16 screened patients. The remaining 9 patients with small-sized abdominal aortic aneurysms have been carefully followed up. CONCLUSIONS: Screening for abdominal aortic aneurysm using ultrasound is advisable especially for male participants and for the detection of iliac aneurysms. This screening procedure is useful for early detection because the screened aneurysm is generally small-sized and impalpable.     

Abdominal aortic aneurysm: A comprehensive review

An arterial aneurysm is defined as a focal dilation of a blood vessel with respect to the original artery. The risk of abdominal aortic aneurysms (AAAs) increases dramatically in the presence of the following factors: age older than 60 years, smoking, hypertension and Caucasian ethnicity. The likelihood that an aneurysm will rupture is influenced by the aneurysm size, expansion rate, continued smoking and persistent hypertension. The majority of AAAs are asymptomatic and are detected as an incidental finding on ultrasonography, abdominal computed tomography or magnetic resonance imaging performed for other purposes. It can also present with abdominal pain or complications such as thrombosis, embolization and rupture. Approximately 30% of asymptomatic AAAs are discovered as a pulsatile abdominal mass on routine physical examination. Abdominal ultrasonography is considered the screening modality of choice for detecting AAAs because of its high sensitivity and specificity, as well as its safety and relatively lower cost. The decision to screen for AAAs is challenging. The United States Preventive Services Task Force recommended that men between the age of 65 to 75 years who have ever smoked should be screened at least once for AAAs by abdominal ultrasonography. Management options for patients with an asymptomatic AAA include reduction of risk factors such as smoking, hypertension and dyslipidemia; medical therapy with beta-blockers; watchful waiting; endovascular stenting; and surgical repair depending on the size and expansion rate of the aneurysm and underlying comorbidities.     

Predictors of aneurysmal formation after surgical correction of aortic coarctation

OBJECTIVES: We sought to identify the predictors of aneurysmal formation after surgical correction of aortic coarctation. BACKGROUND: In 9% of patients, aneurysms develop late after corrective surgery of coarctation of the aorta, with a 36% mortality rate if left untreated. However, the predictors of postsurgical aneurysmal formation are unknown. METHODS: Of 25 aortic aneurysms requiring corrective surgery 152 +/- 78 months after the initial coarctation repair, 8 were located in the ascending aorta (type A) and 17 at the site of previous repair (local type). Seventy-four patients without progression of the aortic diameter within 189 +/- 71 months after coarctation repair were used for categorical data analysis in an attempt to identify the predictors of postsurgical aneurysmal formation. RESULTS: Advanced age at coarctation repair (p = 0.004) and patch graft technique (p < 0.0005) independently predicted local aneurysmal formation. Type A aneurysm was univariately associated with the presence of a bicuspid aortic valve (p = 0.02), advanced age at coarctation repair (p = 0.044) and a high preoperative peak systolic pressure gradient of 74 +/- 21 mm Hg (p = 0.041). Conversely, multivariate analysis confirmed only the presence of a bicuspid aortic valve (p = 0.015) as an independent predictor of type A aneurysm. Receiver operating characteristic curve analysis revealed that 72% of patients with a postsurgical aneurysm had an operation at age 13.5 years or more, whereas 69% with no postsurgical aneurysm had an operation at a younger age. CONCLUSIONS: Use of the patch graft technique and late correction of coarctation can predict aneurysmal formation at the site of coarctation repair, although patients with a bicuspid aortic valve may be at risk for an aneurysm developing in the ascending aorta, particularly after late repair of aortic coarctation with high preoperative pressure gradients.     

Medical management of small abdominal aortic aneurysms

Abdominal aortic aneurysm is a common condition that may be lethal when it is unrecognized. Current guidelines suggest repair as the aneurysm diameter reaches 5.0 to 5.5 cm. Most aortic aneurysms are detected incidentally when imaging is done for other purposes or through screening programs. Ninety percent of these aneurysms are below the threshold for intervention at the time of detection. A number of studies have sought to determine factors that lead to progression of aneurysmal disease that might be amenable to intervention during this period of observation. We review these studies and make recommendations for the medical management of small abdominal aortic aneurysms. On the basis of our current knowledge of the causes of aneurysm, a number of approaches have been proposed to prevent progression of aneurysmal disease. These include hemodynamic management, inhibition of inflammation, and protease inhibition. The American College of Cardiology/American Heart Association clinical practice guidelines rules of evidence have helped to define strength of evidence to support these approaches. Level A evidence (from large randomized trials) is available to indicate that observation of small aneurysms in men is safe up to a size of 5.5 cm and that propranolol does not inhibit aneurysm expansion. Level B evidence (from small randomized trials) suggests that roxithromycin or doxycycline will decrease the rate of aneurysm expansion. A number of studies agree that tobacco use is associated with an increased rate of aneurysm expansion. Level B and C evidence is available to suggest that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) may inhibit aneurysm expansion. There are animal data but no human data demonstrating that angiotensin-converting enzyme inhibitors or losartan, an angiotensin receptor blocker, will decrease the rate of AAA expansion. A pharmacological agent without important side effects that inhibited aneurysm expansion could change current approaches to aneurysm treatment. Additional studies are needed to clarify the potential role of doxycycline, roxithromycin, and statin therapy in the progression of aneurysmal disease.     

Disseminated intravascular coagulation in aortic aneurysms: assessment of consumption site using labeled-platelet scintigraphy.

BACKGROUND: It is known that disseminated intravascular coagulation (DIC) may occur along with aortic aneurysms. To assess the localization of the active consumption site we performed 111In-oxine labeled platelet scintigraphy in patients with chronic aortic aneurysms. METHODS: Images were obtained using 111In-oxine labeled autologous platelets in 45 patients. Planar images were taken twice (at 4 and 48 hrs) after injection. A visual inspection of the radioactivity uptake and special analysis in regions of interest were performed. RESULTS: Thirty-five patients (78%) showed a focal accumulation of radioactivity in the aortic aneurysm. Six of 13 patients (46%) with dissecting aortic aneurysm, and 4 of 32 patients (12.5%) with true aneurysms were evaluated as negative uptake by scintigram (p < 0.05). The aneurysm/heart ratio was 0.85 +/- 0.16 (mean +/- SD) (4 hrs) and 1.09 +/- 0.15 (48 hrs) after injection; the aneurysm/liver ratio was 0.56 +/- 0.16 (4 hrs) and 0.38 +/- 0.09 (48 hrs); the aneurysm/spleen ratio was 0.39 +/- 0.07 (4 hrs) and 0.39 +/- 0.08 (48 hrs). CONCLUSIONS: When the probability of DIC is clinically high in patients with aortic aneurysms, 111In-oxine labeled platelet scintigraphy provides useful preoperative information regarding the location of the functionally active consumption focus.