Mohammad H. Eslami

Predictors of Abdominal Aortic Aneurysm Sac Enlargement After Endovascular Repair

Background— The majority of infrarenal abdominal aortic aneurysm (AAA) repairs in the United States are performed with endovascular methods. Baseline aortoiliac arterial anatomic characteristics are fundamental criteria for appropriate patient selection for endovascular aortic repair (EVAR) and key determinants of long-term success. We evaluated compliance with anatomic guidelines for EVAR and the relationship between baseline aortoiliac arterial anatomy and post-EVAR AAA sac enlargement. Methods and Results— Patients with pre-EVAR and at least 1 post-EVAR computed tomography scan were identified from the M2S, Inc. imaging database (1999 to 2008). Preoperative baseline aortoiliac anatomic characteristics were reviewed for each patient. Data relating to the specific AAA endovascular device implanted were not available. Therefore, morphological measurements were compared with the most liberal and the most conservative published anatomic guidelines as stated in each manufacturers instructions for use. The primary study outcome was post-EVAR AAA sac enlargement (>5-mm diameter increase). In 10 228 patients undergoing EVAR, 59% had a maximum AAA diameter below the 55-mm threshold at which intervention is recommended over surveillance. Only 42% of patients had anatomy that met the most conservative definition of device instructions for use; 69% met the most liberal definition of device instructions for use. The 5-year post-EVAR rate of AAA sac enlargement was 41%. Independent predictors of AAA sac enlargement included endoleak, age ≥80 years, aortic neck diameter ≥28 mm, aortic neck angle >60°, and common iliac artery diameter >20 mm. Conclusion— In this multicenter observational study, compliance with EVAR device guidelines was low and post-EVAR aneurysm sac enlargement was high, raising concern for long-term risk of aneurysm rupture.

Endovascular treatment of ruptured abdominal aortic aneurysms in the United States (2001-2006): A significant survival benefit over open repair is independently associated with increased institutional volume

OBJECTIVE Endovascular aortic repair (EVAR) has gained wide acceptance for the elective treatment of abdominal aortic aneurysms (AAA), leading to interest in similar treatment of ruptured abdominal aortic aneurysms (RAAA). The purpose of this study was to evaluate national outcomes after EVAR for RAAA and to assess the effect of institutional volume metrics. METHODS The Nationwide Inpatient Sample was used to identify patients treated with open or EVAR for RAAA, 2001-2006. Procedure volume was determined for each institution categorizing hospitals as low-, medium-, and high-volume. The primary outcome was in-hospital mortality. Secondary outcomes related to resource utilization. Multivariable logistic regression models were used to determine independent predictors of EVAR usage and mortality. RESULTS From 2001 to 2006, an estimated 27,750 hospital discharges for RAAA occurred; 11.5% were treated with EVAR. EVAR utilization increased over time (5.9% in 2001 to 18.9% in 2006, P < .0001) while overall RAAA rates remained constant. EVAR had a lower overall in-hospital mortality than open repair (31.7% vs 40.7%, P < .0001), an effect which amplified when stratified by institutional volume. On multivariable regression, open repair independently predicted mortality (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.29-1.89). EVAR usage for RAAA increased with age (>80 years) (OR 1.58; 95% CI 1.30-1.93), high elective EVAR volume (>40/y) vs medium (19-40/y) (OR 2.65; 95% CI 1.86-3.78) and low (<19/y) (OR 5.37; 95% CI 3.60-8.0). EVAR had a shorter length of stay (11.1 vs 13.8 days, P < .0001), higher discharges to home (65.1% vs 53.9%, P < .0001), and lower charges (

Carotid artery stenting has increased rates of postprocedure stroke, death, and resource utilization than does carotid endarterectomy in the United States, 2005

108,672 vs

Validation of the PIII CLI risk score for the prediction of amputation-free survival in patients undergoing infrainguinal autogenous vein bypass for critical limb ischemia.

114,784, P < .0001). CONCLUSIONS In the United States, for RAAA, EVAR had a lower postoperative mortality than open repair. Higher elective open repair as well as RAAA volume increased this mortality advantage for EVAR. These results support regionalization of RAAA repair to high volume centers whenever possible and a wider adoption of endovascular repair of RAAA nationwide.

Vascular surgery training trends from 2001-2007: A substantial increase in total procedure volume is driven by escalating endovascular procedure volume and stable open procedure volume

OBJECTIVE Carotid endarterectomy (CEA) remains the procedure of choice for treatment of patients with severe carotid artery stenosis. The role of carotid artery stenting (CAS) in this patient group is still being defined. Prior single and multicenter studies have demonstrated economic savings associated with CEA compared with CAS. The purpose of this study was to compare surgical outcomes and resource utilization associated with these two procedures at the national level in 2005, the first year in which a specific ICD-9 procedure code for CAS was available. METHODS All patient discharges for carotid revascularization for the year 2005 were identified in the Nationwide Inpatient Sample based on ICD9-CM procedure codes for CEA (38.12) and CAS (00.63). The primary outcome measures of interest were in-hospital mortality and postoperative stroke; secondary outcome measures included total hospital charges and length of stay (LOS). All statistical analyses were performed using SAS version 9.1 (Cary, NC), and data are weighted according to the Nationwide Inpatient Sample (NIS) design to draw national estimates. Univariate analyses of categorical variables were performed using Rao-Scott chi(2), and continuous variables were analyzed by survey weighted analysis of variance (ANOVA). Multivariate logistic regression was performed to evaluate independent predictors of postoperative stroke and mortality. RESULTS During 2005, an estimated 135,701 patients underwent either CEA or CAS nationally. Overall, 91% of patients underwent CEA. The mean age overall was 71 years. Postoperative stroke rates were increased for CAS compared with CEA (1.8% vs 1.1%, P < .05), odds ratio (OR) 1.7; (95% confidence interval [CI] 1.2-2.3). Overall, mortality rates were higher for CAS compared with CEA (1.1% vs 0.57%, P < .05) this difference was substantially increased in regard to patients with symptomatic disease (4.6% vs 1.4%, P < .05). By logistic regression, CAS trended toward increased mortality, OR 1.5; (95% CI .96-2.5). Overall, the median total hospital charges for patients that underwent CAS were significantly greater than those that underwent CEA (

National trends in utilization and postprocedure outcomes for carotid artery revascularization 2005 to 2007

30,396 vs

Surgeon case volume, not institution case volume, is the primary determinant of in-hospital mortality after elective open abdominal aortic aneurysm repair

17,658 P < .05). CONCLUSIONS Based on a large representative sample during the year 2005, CEA was performed with significantly lower in-hospital mortality, postoperative stroke rates, and lower median total hospital charges than CAS in US hospitals. As the role for CAS becomes defined for the management of patients with carotid artery stenosis, clinical as well as economic outcomes must be continually evaluated.

Regionalization of abdominal aortic aneurysm repair: Evidence of a shift to high-volume centers in the endovascular era

OBJECTIVE The PREVENT III (PIII) critical limb ischemia (CLI) risk score is a simple, published tool derived from the PIII randomized clinical trial that can be used for estimating amputation-free survival (AFS) in CLI patients considered for infrainguinal bypass (IB). The current study sought to validate this risk stratification model using data from the prospectively collected Vascular Study Group of Northern New England (VSGNNE). METHOD We calculated the PIII CLI risk score for 1166 patients undergoing IB with autogenous vein by 59 surgeons at 11 hospitals between January 1, 2003, and December 31, 2007. Points (pts) were assigned to each patient for the presence of dialysis (4 pts), tissue loss (3 pts), age >or=75 (2 pts), and coronary artery disease (CAD) (1 pt). Baseline hematocrit was not included due to a large proportion of missing values. Total scores were used to stratify each patient into low-risk (<or=3 pts), med-risk (4-7 pts), and high-risk (>or=8 pts) categories. The Kaplan-Meier method was used to calculate AFS for the three risk groups. Log-rank test was used for intergroup comparisons. To assess validation, comparison to the PIII derivation and validation sets was performed. RESULT Stratification of the VSGNNE patients by risk category yielded three significantly different estimates for 1-year AFS (86.4%, 74.0%, and 56.1%, for low-, med-, and high-risk groups). Intergroup comparison demonstrated precise discrimination (P < .0001). For a given risk category (low, med, or high), the 1-year AFS estimates in the VSGNNE dataset were consistent with those observed in the previously published PIII derivation set (85.9%, 73.0%, and 44.6%, respectively), PIII validation set (87.7%, 63.7%, and 45.0%, respectively), and retrospective multicenter validation set (86.3%, 70.1%, and 47.8%, respectively). CONCLUSION The PIII CLI risk score has now been both internally and externally validated by testing it against the outcomes of 3286 CLI patients who underwent autogenous vein bypass at 94 institutions by a diverse array of physicians (three independent cohorts of patients). This tool provides a simple and reliable method to risk stratify CLI patients being considered for IB. At initial consultation, calculation of the PIII CLI risk score can reliably stratify patients according to their risk of death or major amputation at 1 year.

Peripheral arterial interventions: Trends in market share and outcomes by specialty, 1998-2005

BACKGROUND Endovascular procedure volume has increased rapidly, and endovascular procedures have become the initial treatment option for many vascular diseases. Consequently, training in endovascular procedures has become an essential component of vascular surgery training. We hypothesized that, due to this paradigm shift, open surgical case volume may have declined, thereby jeopardizing training and technical skill acquisition in open procedures. METHODS Vascular surgery trainees are required to log both open and endovascular procedures with the Accreditation Council for Graduate Medical Education (ACGME). We analyzed the ACGME database (2001-2007), which records all cases (by Current Procedural Terminology [CPT] code) performed by graduating vascular trainees. Case volume was evaluated according to the mean number of cases performed per graduating trainee. RESULTS The mean number of total major vascular procedures performed per trainee increased by 174% between 2001 and 2007 (from 298.3 to 519.2). Endovascular diagnostic and therapeutic procedures increased by 422% (from 63.7 to 269.1) and accounted for 93.0% of the increase in total procedures. The number of open aortic procedures (aneurysm, occlusive, mesenteric, renal) decreased by 17.1% (from 49.7 to 41.2), while the number of endovascular aortic aneurysm repair procedures increased by 298.8% (from 16.9 to 50.5). Specifically, open aortic aneurysm procedures decreased by 21.8%, aortobifemoral bypass increased by 3.2%, and open mesenteric or renal procedures decreased by 13%. Infrainguinal bypass procedures remained relatively constant (from 37.6 to 36.5, 2.9% decrease), and the number of carotid endarterectomy procedures performed did not change significantly (from 43.6 to 42.2, 3.2% decrease). CONCLUSION Vascular surgery trainees are performing a vastly increased total number of procedures. This increase in total procedure volume is almost entirely attributable to the recent increase in endovascular procedures. Aside from a small decline in open aortic procedures, the volume of open surgical procedures has largely remained stable. It is essential that vascular surgery training programs continue to focus on both endovascular and open surgical skills in order for vascular surgeons to remain the premier specialists to care for patients with vascular disease.

Inhibition of experimental neointimal hyperplasia by recombinant human thrombomodulin coated ePTFE stent grafts

OBJECTIVE This study compared, at a national level, trends in utilization, mortality, and stroke after carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA) from 2005 to 2007. METHODS The Nationwide Inpatient Sample (NIS) was queried for patient discharges with International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes for CAS and CEA. The primary outcomes were in-hospital mortality, stroke, hospital charges, and discharge disposition. Subgroup analyses were performed to evaluate these outcomes by neurologic presentation using χ(2) and multivariable logistic regression. RESULTS Of the 404,256 discharges for carotid revascularization, CAS utilization was 66% higher in 2006 than in 2005 (9.3% vs 14%, P = .0004). Crude mortality, stroke, and median charges remained higher for CAS than for CEA; discharge to home was more common after CEA. Results improved from 2005 to 2007. By logistic regression of the total cohort from 2005 to 2006, CAS was independently predictive of mortality (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.08-2.00; P < .0001). Independent predictors of stroke included CAS (OR, 1.43; 95% CI, 1.18-1.73; P < .0001) and symptomatic disease (OR, 2.4; 95% CI, 2.06-2.93;P < .0001). Among subgroups based on neurological presentation, regression showed that CAS significantly increased the odds of stroke in asymptomatic patients (OR, 1.6; 95% CI, 1.2-2.0; P = .0003). Among symptomatic patients, CAS increased the odds of in-hospital death (OR, 3.0; 95% CI, 1.7-5.1, P < .0001) and trended toward significance for stroke (OR, 1.7; 95% CI, 1.0-2.8; P = .0569). CONCLUSION Utilization of CAS has increased from the years 2005 to 2007 with some improvements in the outcome. Despite improvements in outcome, resource utilization remains significantly higher for CAS than CEA.