Bruce G. Lowman

Evaluating Outcomes of Endoleak Discrepancies Between Computed Tomography Scan and Ultrasound Imaging After Endovascular Abdominal Aneurysm Repair

BACKGROUND Endovascular repair for abdominal aortic aneurysm (EVAR) requires regular surveillance to ensure long-term durability. To understand the clinical consequence of discrepancies in endoleak detection between computed tomographic angiography (CTA) and duplex ultrasound (DUS) imaging, this study evaluated patients who underwent EVAR. The aim of the present study was to determine whether these discrepancies affected the long-term outcome after EVAR, and whether DUS predicted the need for re-intervention on the basis of other markers despite missing endoleaks. METHODS A review of the prospectively maintained database was completed to capture all EVAR procedures performed between October 1999 and June 2009. Patients were routinely evaluated with computed tomography (CT) and DUS imaging within 30 days after the procedure and intermittently at 6-12 month intervals after treatment. DUS imaging was evaluated with attention toward maximum aneurysm diameter, presence of an endoleak, and compared with findings on simultaneous contrast CT imaging. RESULTS The database and patient records identified 1,062 EVARs in 992 patients who underwent 3,120 imaging encounters through the surveillance protocol. Of these 3,120 encounters, 610 had both CT scan and ultrasound at the same visit. Contrast material was not used in 49 CT scans, leaving 561 encounters for comparing contrast CT imaging with DUS results. CT and DUS detection of endoleaks correlated in 442 encounters (78.8%). Discrepancies occurred in 119 encounters (21.2%) as follows: CT scan only endoleak in 17.8% (N = 100; type I = 6, type II = 91, and type III = 3) and DUS only endoleak in 3.4% (N = 19; type II = 19) encounters. Of these 119 encounters, 99 (17.6%) did not require secondary interventions. Eventually, 15 patients required intervention after 20 discrepancy encounters (3.6%): 11 patients continued with the surveillance protocol through CT or DUS imaging, whereas four were observed by CT imaging only. Considering these 11 patients, DUS eventually detected an endoleak on subsequent visits in five patients, DUS identified an increase in aneurysm diameter in four patients, and DUS never identified the type II endoleaks in two patients. When the endoleak raised concern or the aneurysm enlarged, we undertook 19 secondary interventions in these 15 patients: vessel embolization (N = 8), iliac extenders (N = 5), graft relining (N = 3), graft explants (N = 2), and proximal cuff (N = 1). Although three ruptures occurred in our entire treatment experience, no ruptures occurred in patients who maintained the prescribed surveillance protocol. CONCLUSION Surveillance after EVAR is necessary because secondary interventions are sometimes required. Although DUS has lower sensitivity in detecting endoleaks, comparison with CT findings can identify the appropriate patients for DUS surveillance only. Even considering the discrepancies between CT imaging and DUS, repeated DUS surveillance might identify an unstable aneurysm that requires further intervention. Although DUS has not been established as an exclusive surveillance tool, it can be used to effectively monitor patients after EVAR with reduced need for CT imaging.

Dual antiplatelet therapy (clopidogrel and aspirin) is associated with increased all-cause mortality after carotid revascularization for asymptomatic carotid disease

OBJECTIVE Despite the established guidelines, there is not a clear consensus about how to manage antiplatelet therapy after carotid surgery. It is a common practice in vascular surgery to use the combination of aspirin and clopidogrel in the treatment of such patients. In this work, we analyzed the impact on long-term survival of antiplatelet therapy in patients treated for carotid stenosis at a single institution over a 10-year period. METHODS Outcomes of 471 patients who underwent carotid intervention (1999-2008) were analyzed. Discharge prescription summaries were retrieved, and patients were divided into two groups according to their antiplatelet regimen: aspirin-only group and aspirin plus clopidogrel group. Only patients with a minimum of 30 days of confirmed antiplatelet therapy were included. All-cause mortality during follow-up represented the primary outcome, whereas stroke and bleeding at 30 days and during follow-up represented secondary end points. When local records were sparse, the Social Security Death Index was queried to confirm mortality. The International Classification of Diseases, 9th Revision (ICD-9 codes), was reviewed for treatment related to a bleeding condition. RESULTS When divided by indication, there was an increased mortality rate in patients with asymptomatic carotid disease receiving dual antiplatelet therapy as compared with aspirin alone (47% vs 40%; P = .05). Patients with symptomatic carotid disease had a nonsignificant decrease in all-cause mortality if they received dual antiplatelet therapy (38% vs 39%; P = .53). In a subgroup analysis, there was a significant increase in the rate of all-cause mortality among patients older than 75 years receiving dual antiplatelet therapy for asymptomatic carotid disease (82% vs 56%; P = .001), whereas there was a nonsignificant decrease in mortality in patients older than 75 years receiving dual antiplatelet therapy for symptomatic carotid disease (47% vs 63%; P = .50). There was no difference in secondary outcomes (stroke and bleeding) regardless of the indication or the antiplatelet therapy. CONCLUSIONS In this retrospective, single-institution study, the use of dual antiplatelet therapy (aspirin plus clopidogrel) in patients intervened for asymptomatic carotid disease was related to increased all-cause mortality, whereas it did not significantly influence the outcome in patients with symptomatic carotid disease.

Effect of lipid-modifying drug therapy on survival after abdominal aortic aneurysm repair.

BACKGROUND Lipid-modifying drug therapy (LMDT) is recommended in all patients having coronary or noncoronary atherosclerotic disease. However, the effect of LMDT after abdominal aortic aneurysm (AAA) repair, especially in the absence of other atherosclerotic manifestations, is unclear. We examined the distribution of prevalence of LMDT among patients undergoing AAA repair and its effect on survival in the presence and absence of other atherosclerotic diseases. METHODS We identified patients treated at University of Alabama at Birmingham between 1985 and 2010 who had a prior AAA repair. Information was collected from health system medical charts, medical communication, and national death indices. We assessed the predictors of prevalence of LMDT by univariate analysis using t-test for continuous and χ(2) test for categorical variables, and then performed multivariate logistic regression. The survival was determined using Kaplan-Meier plots, and adjusted hazard ratios were calculated using Cox proportion regression. RESULTS A total of 2063 patients underwent AAA repair procedure. Of these, 9% were African-American, and 20% were female. Thirty-five percent received LMDT, and 32% died during the follow-up period of up to 240 months. Significant predictors for being on LMDT included white race (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2), presence of other atherosclerotic disease or diabetes (OR, 2.4; 95% CI, 1.9-3.0), hypertension (OR, 4.0; 95% CI, 3.1-5.2), smoking (OR, 1.6; 95% CI, 1.2-2.1), and endovascular AAA repair (OR, 1.9; 95% CI, 1.5-2.3). LMDT was associated with improved survival (hazard ratio, 0.6; 95% CI, 0.5-0.8) after controlling for traditional risk factors, diabetes, and other atherosclerotic diseases. CONCLUSIONS LMDT after AAA is associated with an increased survival compared with patients who were not using drug therapy for dyslipidemia. Aggressive management of dyslipidemia should be considered in all patients undergoing AAA repair irrespective of other atherosclerotic disease status and risk factor profile.