Jeffrey Jim

Treatment and outcomes of aortic endograft infection

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.

Outcome-based anatomic criteria for defining the hostile aortic neck

OBJECTIVE There is abundant evidence linking hostile proximal aortic neck anatomy to poor outcome after endovascular aortic aneurysm repair (EVAR), yet the definition of hostile anatomy varies from study to study. This current analysis was undertaken to identify anatomic criteria that are most predictive of success or failure at the aortic neck after EVAR. METHODS The study group comprised 221 patients in the Aneurysm Treatment using the Heli-FX Aortic Securement System Global Registry (ANCHOR) clinical trial, a population enriched with patients with challenging aortic neck anatomy and failure of sealing. Imaging protocols were not protocol specified but were performed according to the institutions standard of care. Core laboratory analysis assessed the three-dimensional centerline-reformatted computed tomography scans. Failure at the aortic neck was defined by type Ia endoleak occurring at the time of the initial endograft implantation or during follow-up. Receiver operating characteristic curve analysis was used to assess the value of each anatomic measure in the classification of aortic neck success and failure and to identify optimal thresholds of discrimination. Binary logistic regression was performed after excluding highly intercorrelated variables, creating a final model with significant predictors of outcome after EVAR. RESULTS Among the 221 patients, 121 (54.8%) remained free of type Ia endoleak and 100 (45.2%) did not. Type Ia endoleaks presented immediately after endograft deployment in 58 (58.0%) or during follow-up in 42 (42.0%). Receiver operating characteristic curve analysis identified 12 variables where the classification of patients with type Ia endoleak was significantly more accurate than chance alone. Increased aortic neck diameter at the lowest renal artery (P = .013) and at 5 mm (P = .008), 10 mm (P = .008), and 15 mm (P = .010) distally; aneurysm sac diameter (P = .001), common iliac artery diameters (right, P = .012; left, P = .032), and a conical (P = .049) neck configuration were predictive of endoleak. By contrast, increased aortic neck length (P = .050), a funnel-shaped aortic neck (P = .036), and neck mural thrombus content, as measured by average thickness (P = .044) or degrees of circumferential coverage (P = .029), were protective against endoleak. Binary logistic regression identified three variables independently predictive of type Ia endoleak. Neck diameter at the lowest renal artery (P = .002, cutpoint 26 mm) and neck length (P = .017, cutpoint 17 mm) were associated with endoleak, whereas some mural neck thrombus content was protective (P = .001, cutpoint 11° of circumferential coverage). CONCLUSIONS A limited number of independent anatomic variables are predictive of type Ia endoleak after EVAR, including aortic neck diameter and aortic neck length, whereas mural thrombus in the neck is protective. This study suggests that anatomic measures with identifiable threshold cutpoints should be considered when defining the hostile aortic neck and assessing the risk of complications after EVAR.

Population-based analysis of inpatient vascular procedures and predicting future workload and implications for training

OBJECTIVE The purpose of this study was to analyze the trend in inpatient vascular procedures in the United States over the past decade and predict the future demand for vascular surgeons. METHODS The Healthcare Cost and Utilization Project Nationwide Inpatient Sample was queried to determine the weighted national estimates of inpatient vascular procedures performed on adult patients (age ≥ 18) between 1997 and 2008. Using population estimates from the United States Census Bureau, the per capita rates of inpatient procedures were calculated for age-specific groups (18-64 years, 65-84 years, and ≥ 85 years). The change in per capita rates over the past decade along with population forecasts were used to predict future workload. RESULTS There was a net increase of 22% from 971,046 inpatient vascular procedures for all adults in 1997 to 1,188,332 in 2008. During the same time period, the adult population increased by 16% from 198 to 230 million. The age-stratified per capita rates of all vascular procedures were +21% for age 18 to 64; -4% for age 65 to 84; and +18% for age ≥ 85. This resulted in a net increase of 5% (490 to 515 procedures per 100,000 capita) in the per capita rate for all adults. Based on the assumption that trends in age-specific rates remain constant, there is a predicted inpatient workload increase (compared to 2008) of 18% by 2015, 34% by 2020, and 72% by 2030. The vascular workload is predicted to more than double by the year 2040. CONCLUSIONS Despite a conservative approach of using a population-based analysis of only inpatient procedures, there is a dramatic increase in the predicted vascular workload for the future. The vascular surgery training process will need to adapt to ensure an adequate number of fellowship-trained vascular surgeons is available to provide quality vascular care in the future.

Society for Vascular Surgery Vascular Registry evaluation of stent cell design on carotid artery stenting outcomes.

OBJECTIVE The Society for Vascular Surgery (SVS) Vascular Registry (VR) collects data on outcomes of carotid endarterectomy and carotid artery stenting (CAS). The purpose of this study was to evaluate the impact of open vs closed cell stent design on the in-hospital and 30-day outcome of CAS. METHODS The VR collects provider-reported data on patients using a Web-based database. Data were analyzed both in-hospital and at 30 days postprocedure. The primary outcome is combined death/stroke/myocardial infarction (MI). RESULTS As of October 14, 2009, there were 4337 CAS with discharge data and 2397 with 30-day data. Open cell stents (OPEN) were used in 3451 patients (79.6%), and closed cell stents (CLOSED) were used in 866 patients (20.4%). Baseline demographics showed no differences in age, gender, race, and ethnicity. However, the OPEN group had more patients with atherosclerosis (74.5% vs 67.4%; P = .0003) as the etiology of carotid artery disease. The OPEN group also had a higher prevalence of preprocedural stroke (25.8% vs 21.4%; P = .0079), chronic obstructive pulmonary disease (COPD; 21.0% vs 17.6%; P = .0277), cardiac arrhythmia (14.7% vs 11.4%; P = .0108), valvular heart disease (7.4% vs 3.7%; P < .0001), peripheral vascular disease (PVD; 40.0% vs 35.3%; P = .0109), and smoking history (59.0% vs 54.1%; P = .0085). There are no statistically significant differences in the in-hospital or 30-day outcomes between the OPEN and CLOSED patients. Further subgroup analyses demonstrated symptomatic patients had a higher event rate than the asymptomatic cohort in both the OPEN and CLOSED groups. Among symptomatic patients, the OPEN patients had a lower (0.43% vs 1.41%; P = .0349) rate of in-hospital mortality with no difference in stroke or transient ischemic attack (TIA). There were no differences in 30-day event rates. In asymptomatic patients, there were also no statistically significant differences between the OPEN and CLOSED groups. After risk adjustment, there remained no statistically significant differences between groups of the primary endpoint (death/stroke/MI) during in-hospital or 30 days. CONCLUSION In-hospital and 30-day outcomes after CAS were not significantly influenced by stent cell design. Symptomatic patients had higher adverse event rates compared to the asymptomatic cohort. As there is no current evidence of differential outcome between the use of open and closed cell stents, physicians should continue to use approved stent platforms based on criteria other than stent cell design.

Long-term outcome of endovascular popliteal artery aneurysm repair.

BACKGROUND Popliteal artery aneurysms have traditionally been repaired with an open surgical approach. However, endovascular popliteal artery repair (EVPAR) has been used in selected patients because of its less invasive nature. In this report, we present our long-term outcomes for EVPAR. METHODS Retrospective review of all patients who underwent EVPAR at a single academic institution between September 2002 and March 2006. These patients were evaluated for patency, need for secondary intervention, amputation-free survival, and overall survival. RESULTS A total of 15 limbs in 13 patients were treated with EVPAR during the study period. All EVPAR were performed using the Viabahn(®) endoprostheses, with an average of 1.67 stents per limb. The mean age of the patients was 74.6 years (range, 66-84). Technical success was achieved in 100% and all limbs had initial postoperative ankle-arm indices of ≥ 1.0. Mean duration of follow-up was 54 months (range, 42-70). Two patients died of unrelated causes at 3 and 38 months with intact limbs, and one patient was lost to follow-up. Two limbs developed type I or III endoleaks, and were successfully treated with additional endovascular stent placement, resulting in a primary patency rate of 84.6% and secondary patency rate of 100%. There were no instances of limb loss during the follow-up period, yielding both amputation-free survival and overall survival rates of 85.7%. CONCLUSIONS Long-term follow-up of this cohort of EVPAR patients suggests that in selected patients, this is a durable technique, capable of achieving excellent patency rates and limb preservation. Further large-scale clinical trials are warranted to help define optimal candidates for this technique.

Society for Vascular Surgery (SVS) Vascular Registry evaluation of comparative effectiveness of carotid revascularization procedures stratified by Medicare age

OBJECTIVE Recent randomized controlled trials have shown that age significantly affects the outcome of carotid revascularization procedures. This study used data from the Society for Vascular Surgery Vascular Registry (VR) to report the influence of age on the comparative effectiveness of carotid endarterectomy (CEA) and carotid artery stenting (CAS). METHODS VR collects provider-reported data on patients using a Web-based database. Patients were stratified by age and symptoms. The primary end point was the composite outcome of death, stroke, or myocardial infarction (MI) at 30 days. RESULTS As of December 7, 2010, there were 1347 CEA and 861 CAS patients aged < 65 years and 4169 CEA and 2536 CAS patients aged ≥ 65 years. CAS patients in both age groups were more likely to have a disease etiology of radiation or restenosis, be symptomatic, and have more cardiac comorbidities. In patients aged <65 years, the primary end point (5.23% CAS vs 3.56% CEA; P = .065) did not reach statistical significance. Subgroup analyses showed that CAS had a higher combined death/stroke/MI rate (4.44% vs 2.10%; P < .031) in asymptomatic patients but there was no difference in the symptomatic (6.00% vs 5.47%; P = .79) group. In patients aged ≥ 65 years, CEA had lower rates of death (0.91% vs 1.97%; P < .01), stroke (2.52% vs 4.89%; P < .01), and composite death/stroke/MI (4.27% vs 7.14%; P < .01). CEA in patients aged ≥ 65 years was associated with lower rates of the primary end point in symptomatic (5.27% vs 9.52%; P < .01) and asymptomatic (3.31% vs 5.27%; P < .01) subgroups. After risk adjustment, CAS patients aged ≥ 65 years were more likely to reach the primary end point. CONCLUSIONS Compared with CEA, CAS resulted in inferior 30-day outcomes in symptomatic and asymptomatic patients aged ≥ 65 years. These findings do not support the widespread use of CAS in patients aged ≥ 65 years.

The impact of Centers for Medicare and Medicaid Services high-risk criteria on outcome after carotid endarterectomy and carotid artery stenting in the SVS Vascular Registry

OBJECTIVE The Centers for Medicare and Medicaid Services (CMS) require high-risk (HR) criteria for carotid artery stenting (CAS) reimbursement. The impact of these criteria on outcomes after carotid endarterectomy (CEA) and CAS remains uncertain. Additionally, if these HR criteria are associated with more adverse events after CAS, then existing comparative effectiveness analysis of CEA vs CAS may be biased. We sought to elucidate this using data from the SVS Vascular Registry. METHODS We analyzed 10,107 patients undergoing CEA (6370) and CAS (3737), stratified by CMS HR criteria. The primary endpoint was composite death, stroke, and myocardial infarction (MI) (major adverse cardiovascular event [MACE]) at 30 days. We compared baseline characteristics and outcomes using univariate and multivariable analyses. RESULTS CAS patients were more likely to have preoperative stroke (26% vs 21%) or transient ischemic attack (23% vs 19%) than CEA. Although age ≥ 80 years was similar, CAS patients were more likely to have all other HR criteria. For CEA, HR patients had higher MACEs than normal risk in both symptomatic (7.3% vs 4.6%; P < .01) and asymptomatic patients (5% vs 2.2%; P < .0001). For CAS, HR status was not associated with a significant increase in MACE for symptomatic (9.1% vs 6.2%; P = .24) or asymptomatic patients (5.4% vs 4.2%; P = .61). All CAS patients had MACE rates similar to HR CEA. After multivariable risk adjustment, CAS had higher rates than CEA for MACE (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.0-1.5), death (OR, 1.5; 95% CI, 1.0-2.2), and stroke (OR, 1.3; 95% CI,1.0-1.7), whereas there was no difference in MI (OR, 0.8; 95% CI, 0.6-1.3). Among CEA patients, age ≥ 80 (OR, 1.4; 95% CI, 1.02-1.8), congestive heart failure (OR, 1.7; 95% CI, 1.03-2.8), EF <30% (OR, 3.5; 95% CI, 1.6-7.7), angina (OR, 3.9; 95% CI, 1.6-9.9), contralateral occlusion (OR, 3.2; 95% CI, 2.1-4.7), and high anatomic lesion (OR, 2.7; 95% CI, 1.33-5.6) predicted MACE. Among CAS patients, recent MI (OR, 3.2; 95% CI, 1.5-7.0) was predictive, and radiation (OR, 0.6; 95% CI, 0.4-0.8) and restenosis (OR, 0.5; 95% CI, 0.3-0.96) were protective for MACE. CONCLUSIONS Although CMS HR criteria can successfully discriminate a group of patients at HR for adverse events after CEA, certain CMS HR criteria are more important than others. However, CEA appears safer for the majority of patients with carotid disease. Among patients undergoing CAS, non-HR status may be limited to restenosis and radiation.

Gender-specific 30-day outcomes after carotid endarterectomy and carotid artery stenting in the Society for Vascular Surgery Vascular Registry

OBJECTIVE Although the optimal treatment of carotid stenosis remains unclear, available data suggest that women have higher risk of adverse events after carotid revascularization. We used data from the Society for Vascular Surgery Vascular Registry to determine the effect of gender on outcomes after carotid endarterectomy (CEA) and carotid artery stenting (CAS). METHODS There were 9865 patients (40.6% women) who underwent CEA (n = 6492) and CAS (n = 3373). The primary end point was a composite of death, stroke, and myocardial infarction at 30 days. RESULTS There was no difference in age and ethnicity between genders, but men were more likely to be symptomatic (41.6% vs 38.6%; P < .003). There was a higher prevalence of hypertension and chronic obstructive pulmonary disease in women, whereas men had a higher prevalence of coronary artery disease, history of myocardial infarction, and smoking history. For disease etiology in CAS, restenosis was more common in women (28.7% vs 19.7%; P < .0001), and radiation was higher in men (6.2% vs 2.6%; P < .0001). Comparing by gender, there were no statistically significant differences in the primary end point for CEA (women, 4.07%; men, 4.06%) or CAS (women, 6.69%; men, 6.80%). There remains no difference after stratification by symptomatology and multivariate risk adjustment. CONCLUSIONS In this large, real-world analysis, women and men demonstrated similar results after CEA or CAS. These data suggest that, contrary to previous reports, women do not have a higher risk of adverse events after carotid revascularization.

A 5-Year Comparison of EVAR for Large and Small Aortic Necks

Purpose: To compare the long-term outcomes of endovascular aneurysm repair (EVAR) using the Talent endograft for abdominal aortic aneurysms (AAAs) with large and small aortic necks. Methods: Data on 156 patients (142 men; mean age 74.1 years, range 41–89) with adequate preoperative imaging were obtained from the prospective, nonrandomized, multicenter Talent eLPS trial, which enrolled patients from February 2002 to April 2003. Subgroup analyses were performed for AAAs with a large aortic neck diameter (≥28 mm; n=53, group 1) and those with smaller necks (<28 mm; n = 103, group 2). Safety and effectiveness endpoints were evaluated at 30 days, 1 year, and 5 years post procedure. Results: Patients in both groups had similar gender and risk factor profiles. However, group 1 was significantly older (mean age 76.5 versus 72.9 years; p<0.01). Aside from neck diameter, the 2 groups had similar mean neck length and angulation. Group 1 also had a larger maximum aneurysm diameter (mean 58.2 versus 53.4 mm; p<0.01). At 1 year, the 2 groups had similar effectiveness endpoint results. There was a significantly lower freedom from major adverse events (MAEs) for group 1 at 30 days (79.2% versus 95.1%; p<0.01). While this trend continued to 1 year, the difference lost statistical significance (72.0% versus 85.1%; p=0.08). Freedom from all-cause mortality at 30 days (94.4% versus 100%; p<0.04) and aneurysm-related death at 1 year (93.3 versus 100%; p<0.04) also was significantly lower for group 1. At 5 years, there were no significant differences in the rates of endoleaks or aneurysm changes. The 5-year rates for freedom from aneurysm-related mortality for groups 1 and 2 were 91.2% and 98.7% (p=NS), respectively. There were 5 instances of migration in this study, all occurring in group 1 patients. Conclusion: AAAs with aortic necks ≥28 mm can be treated with endovascular devices with acceptable results at 5 years. However, these patients have a higher rate of MAEs within the first year and higher migration rates at 5 years. In addition, they have a lower freedom from all-cause mortality at 30 days and aneurysm-related death at 1 year. Careful patient selection, accurate device deployment, and continued follow-up are necessary to optimize long-term results in this patient population.

Implantable Carotid Sinus Stimulator for the Treatment of Resistant Hypertension: Local Effects on Carotid Artery Morphology

BACKGROUND The Rheos System is a chronically implanted carotid sinus baroreflex activating system with a pulse generator and bilateral perivascular carotid sinus leads (CSLs) that is being evaluated in prospective clinical trials for the treatment of drug-resistant hypertension. We evaluated carotid artery structural integrity after implantation of the CSLs. METHODS To assess the effect of chronic CSL attachment, 29 CSLs were implanted on the common carotid arteries of eight sheep. The studies were terminated at 3 and 6 months postimplantation to assess anatomic and histologic changes. Additionally, 10 patients with resistant hypertension were enrolled in the Rheos Multicenter Feasibility Trial. Duplex ultrasound (DUS) was performed before device implantation and at 1 and 4 months postimplantation in this patient cohort. An independent core laboratory assessed all DUSs. RESULTS Ovine carotid angiography revealed no significant stenoses, while anatomic and histologic evaluations demonstrated electrode encapsulation in a thin layer of connective tissue with no evidence of stenosis, erosion, or inflammation. DUS evaluation revealed no significant increase in peak systolic velocities of the common and internal carotid arteries 1 and 4 months after initial implantation, indicating a lack of injury, remodeling, or stenosis. CONCLUSION The current data suggest that the CSLs used with the Rheos System are not associated with the development of carotid stenosis or injury. These short-term data support the concept of CSL placement and merit long-term investigation in a larger multicenter prospective trial.