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As endovascular aortic aneurysm repair (EVAR) matures into its third decade, measures such as long-term reintervention and readmission have become a focus of quality improvement efforts. Within a large United States integrated health care system, we describe time trends in the rates of long-term reinterventions utilization measures.Data from a United States multiregional EVAR registry was used to perform a descriptive study of 3891 adults who underwent conventional infrarenal EVAR for infrarenal abdominal aortic aneurysm between 2010 and 2019. Three-year follow-up was 96.7%. Outcomes included 1-, 3-, and 5-year graft revision (defined as a procedure involving placement of a new endograft component), secondary interventions (defined as a procedure necessary for maintenance of EVAR integrity [eg, coil embolization and balloon angioplasty/stenting]), conversion to open, interventions for type II endoleaks alone, and 90-day readmission. Crude cause-specific reintervention probabilities were calculated by operative year using the Aalen-Johansen estimator, with death as a competing risk and December 31, 2020 as the study end date.Excluding interventions for type II endoleak alone, 1-year secondary intervention incidence decreased from 5.9% for EVARs in 2010 to 2.0% in 2019 (P .001) and 3-year incidence decreased from 7.2% to 3.6% from 2010 to 2017 (P = .03). The 3-year incidences of graft revision (mean incidence, 3.4%) and conversion to open remained fairly stable (mean incidence, 0.6%) over time. The 3-year incidence of interventions for type II endoleak alone also decreased from 3.4% in 2010 to 0.7% in 2017 (P = .01). Ninety-day readmission rates decreased from 19.3% for index EVAR in 2010 to 9.2% in 2019 (P = .03).Comprehensive data from a multiregional health care system demonstrates decreasing long-term secondary intervention and readmission rates over time in patients undergoing EVAR. These trends are not explained by evolving management of type II endoleaks and suggest improving graft durability, patient selection, or surgical technique. Further study is needed to define implant and anatomic predictors of different types of long-term reintervention.

Background: Moderate carotid artery stenosis is a poorly defined risk factor for ischemic stroke. As such, practice recommendations are lacking. In this study, we describe the long-term risk of stroke in patients with moderate asymptomatic stenosis in an integrated health care system. Methods: All adult patients with asymptomatic moderate (50%–69%) internal carotid artery stenosis between 2008 and 2012 were identified, with follow-up through 2017. The primary outcome was acute ischemic stroke attributed to the ipsilateral carotid artery. Stroke rates were calculated using competing risk analysis. Secondary outcomes included disease progression, ipsilateral intervention, and long-term survival. Results: Overall, 11 614 arteries with moderate stenosis in 9803 patients were identified. Mean age was 74.2±9.9 years with 51.4% women. Mean follow-up was 5.1±2.9 years. There were 180 ipsilateral ischemic strokes (1.6%) identified (crude annual risk, 0.31% [95% CI, 0.21%–0.41%]), of which thirty-one (17.2%) underwent subsequent intervention. Controlling for death and intervention as competing risks, the cumulative incidence of stroke was 1.2% (95% CI, 1.0%–1.4%) at 5 years and 2.0% (95% CI, 1.7%–2.4%) at 10 years. Of identified strokes, 50 (27.8%) arteries had progressed to severe stenosis or occlusion. During follow-up, there were 17 029 carotid studies performed in 5951 patients, revealing stenosis progression in 1674 (14.4%) arteries, including 1614 (13.9%) progressing to severe stenosis and 60 (0.5%) to occlusion. The mean time to stenosis progression was 2.6±2.1 years. Carotid intervention occurred in 708 arteries (6.1%). Of these, 66.1% (468/708) had progressed to severe stenosis. The overall mortality rate was 44.5%, with 10.5% of patients lost to follow-up. Conclusions: In this community-based sample of patients with asymptomatic moderate internal carotid artery stenosis followed for an average of 5 years, the cumulative incidence of stroke is low out to 10 years. Future research is needed to optimize management strategies for this population.

Management of carotid bifurcation stenosis in stroke prevention has been the subject of extensive investigations, including multiple randomized controlled trials. The proper treatment of patients with carotid bifurcation disease is of major interest to vascular surgeons and other vascular specialists. In 2011, the Society for Vascular Surgery published guidelines for the treatment of carotid artery disease. At the time, several randomized trials, comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS), were reported. Since the 2011 guidelines, several studies and a few systematic reviews comparing CEA and CAS have been reported, and the role of medical management has been reemphasized. In the present publication, we have updated and expanded on the 2011 guidelines with specific emphasis on five areas: (1) is CEA recommended over maximal medical therapy for low-risk patients; (2) is CEA recommended over transfemoral CAS for low surgical risk patients with symptomatic carotid artery stenosis of50%; (3) the timing of carotid intervention for patients presenting with acute stroke; (4) screening for carotid artery stenosis in asymptomatic patients; and (5) the optimal sequence of intervention for patients with combined carotid and coronary artery disease. A separate implementation document will address other important clinical issues in extracranial cerebrovascular disease. Recommendations are made using the GRADE (grades of recommendation assessment, development, and evaluation) approach, as was used for other Society for Vascular Surgery guidelines. The committee recommends CEA as the first-line treatment for symptomatic low-risk surgical patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 70% to 99%. The perioperative risk of stroke and death in asymptomatic patients must be 3% to ensure benefit for the patient. In patients with recent stable stroke (modified Rankin scale score, 0-2), carotid revascularization is considered appropriate for symptomatic patients with50% stenosis and should be performed as soon as the patient is neurologically stable after 48 hours but definitely 14 days after symptom onset. In the general population, screening for clinically asymptomatic carotid artery stenosis in patients without cerebrovascular symptoms or significant risk factors for carotid artery disease is not recommended. In selected asymptomatic patients with an increased risk of carotid stenosis, we suggest screening for clinically asymptomatic carotid artery stenosis as long as the patients would potentially be fit for and willing to consider carotid intervention if significant stenosis is discovered. For patients with symptomatic carotid stenosis of 50% to 99%, who require both CEA and coronary artery bypass grafting, we suggest CEA before, or concomitant with, coronary artery bypass grafting to potentially reduce the risk of stroke and stroke/death. The sequencing of the intervention depends on the clinical presentation and institutional experience.

Objective Contemporary data on the natural history of large abdominal aortic aneurysms (AAAs) in patients undergoing delayed or no repair are lacking. In this study, we examine the impact of large AAA size on the incidence of rupture and mortality. Methods From a prospectively maintained aneurysm surveillance registry, patients with an unrepaired, large AAA (≥5.5 cm in men and ≥5.0 cm in women) at baseline (ie, index imaging) or who progressed to a large size from 2003 to 2017 were included, with follow-up through March 2020. Outcomes of interest obtained by manual chart review included rupture (confirmed by imaging/autopsy), probable rupture (timing/findings consistent with rupture without more likely cause of death), repair, reasons for either no or delayed (>1 year after diagnosis of large AAA) repair and total mortality. Cumulative incidence of rupture was calculated using a nonparametric cumulative incidence function, accounting for the competing events of death and aneurysm repair and was stratified by patient sex. Results Of the 3248 eligible patients (mean age, 83.6 ± 9.1 years; 71.2% male; 78.1% white; and 32.0% current smokers), 1423 (43.8%) had large AAAs at index imaging, and 1825 progressed to large AAAs during the follow-up period, with a mean time to qualifying size of 4.3 ± 3.4 years. In total, 2215 (68%) patients underwent repair, of which 332 were delayed >1 year; 1033 (32%) did not undergo repair. The most common reasons for delayed repair were discrepancy in AAA measurement between surgeon and radiologist (34%) and comorbidity (20%), whereas the most common reasons for no repair were patient preference (48%) and comorbidity (30%). Among patients with delayed repair (mean time to repair, 2.6 ± 1.8 years), nine (2.7%) developed symptomatic aneurysms, and an additional 11 (3.3%) ruptured. Of patients with no repair, 94 (9.1%) ruptured. The 3-year cumulative incidence of rupture was 3.4% for initial AAA size 5.0 to 5.4 cm (women only), 2.2% for 5.5 to 6.0 cm, 6.0% for 6.1 to 7.0 cm, and 18.4% for >7.0 cm. Women with AAA size 6.1 to 7.0 cm had a 3-year cumulative incidence of rupture of 12.8% (95% confidence interval, 7.5%-19.6%) compared with 4.5% (95% confidence interval, 3.0%-6.5%) in men (P = .002). Conclusions In this large cohort of AAA registry patients over 17 years, annual rupture rates for large AAAs were lower than previously reported, with possible increased risk in women. Further analyses are ongoing to identify those at increased risk for aneurysm rupture and may provide targeted surveillance regimens and improve patient counseling.

Background Endologix issued important safety updates for the AFX Endovascular AAA System in 2016 and 2018 owing to the risk of type III endoleaks. Outcomes with these devices are limited to small case series with short-term follow-up. We describe the midterm outcomes for a large cohort of patients who received an Endologix AFX or AFX2 device. Study design Data from an integrated healthcare system's implant registry, which prospectively monitors all patients after endovascular aortic repair, was used for this descriptive study. Patients undergoing endovascular aortic repair with three AFX System variations (Strata [AFX-S], Duraply [AFX-D], and AFX2 with Duraply [AFX2]) were identified (2011-2017). Crude cumulative event probabilities for endoleak (types I and III), major reintervention, conversion to open, rupture, and mortality (aneurysm related and all cause) were estimated. Results Among 605 patients, 375 received AFX-S, 197 received AFX-D, and 33 received AFX2. Median follow-up for the cohort was 3.9 (interquartile range, 2.5-5.1) years. The crude 2-year incidence of overall endoleak, any subsequent reintervention or conversion, and mortality was 8.8% (95% confidence interval [CI], 6.3-12.3), 12.0% (95% CI, 9.1-15.9), and 8.8% (95% CI, 6.3-12.2) for AFX-S. Respective estimates for AFX-D were 7.9% (95% CI, 4.8-13.0), 10.6% (95% CI, 6.9-16.1), and 9.7% (95% CI, 6.3-14.7); for AFX2, they were 14.1% (95% CI, 4.7-38.2), 16.2% (95% CI, 6.4-37.7), and 21.2% (95% CI, 10.7-39.4). Conclusions The midterm outcomes of a large U.S. patient cohort with an Endologix AFX or AFX2 System demonstrate a concerning rate of adverse postoperative events. Patients with these devices should receive close clinical surveillance to prevent device-related adverse events.

IMPORTANCE: Optimal management of patients with asymptomatic severe carotid stenosis is uncertain, due to advances in medical care and a lack of contemporary data comparing medical and surgical treatment. OBJECTIVE: To estimate stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not undergo surgical intervention. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study that included 3737 adult participants with asymptomatic severe (70%-99%) carotid stenosis diagnosed between 2008 and 2012 and no prior intervention or ipsilateral neurologic event in the prior 6 months. Participants received follow-up through 2019, and all were members of an integrated US regional health system serving 4.5 million members. EXPOSURES: Imaging diagnosis of asymptomatic carotid stenosis of 70% to 99%. MAIN OUTCOMES AND MEASURES: Occurrence of ipsilateral carotid-related acute ischemic stroke. Censoring occurred with death, disenrollment, or ipsilateral intervention. RESULTS: Among 94 822 patients with qualifying imaging studies, 4230 arteries in 3737 (mean age, 73.8 [SD 9.5 years]; 57.4% male) patients met selection criteria including 2539 arteries in 2314 patients who never received intervention. The mean follow-up in this cohort was 4.1 years (SD 3.6 years). Prior to any intervention, there were 133 ipsilateral strokes with a mean annual stroke rate of 0.9% (95% confidence interval [CI], 0.7%-1.2%). The Kaplan-Meier estimate of ipsilateral stroke by 5 years was 4.7% (95% CI, 3.9%-5.7%). CONCLUSIONS AND RELEVANCE: In a community-based cohort of patients with asymptomatic severe carotid stenosis who did not undergo surgical intervention, the estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% over 5 years. These findings may inform decision-making regarding surgical and medical treatment for patients with asymptomatic severe carotid artery stenosis.

Objective Investigation of asymptomatic carotid stenosis treatment is hindered by the lack of a contemporary population-based disease cohort. We describe the use of natural language processing (NLP) to identify stenosis in patients undergoing carotid imaging. Methods Adult patients with carotid imaging between 2008 and 2012 in a large integrated health care system were identified and followed through 2017. An NLP process was developed to characterize carotid stenosis according to the Society of Radiologists in Ultrasound (for ultrasounds) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) (for axial imaging) guidelines. The resulting algorithm assessed text descriptors to categorize normal/non-hemodynamically significant stenosis, moderate or severe stenosis as well as occlusion in both carotid ultrasound (US) and axial imaging (computed tomography and magnetic resonance angiography [CTA/MRA]). For US reports, internal carotid artery systolic and diastolic velocities and velocity ratios were assessed and matched for laterality to supplement accuracy. To validate the NLP algorithm, positive predictive value (PPV or precision) and sensitivity (recall) were calculated from simple random samples from the population of all imaging studies. Lastly, all non-normal studies were manually reviewed for confirmation for prevalence estimates and disease cohort assembly. Results A total of 95,896 qualifying index studies (76,276 US and 19,620 CTA/MRA) were identified among 94,822 patients including 1059 patients who underwent multiple studies on the same day. For studies of normal/non-hemodynamically significant stenosis arteries, the NLP algorithm showed excellent performance with a PPV of 99% for US and 96.5% for CTA/MRA. PPV/sensitivity to identify a non-normal artery with correct laterality in the CTA/MRA and US samples were 76.9% (95% confidence interval [CI], 74.1%-79.5%)/93.1% (95% CI, 91.1%-94.8%) and 74.7% (95% CI, 69.3%-79.5%)/94% (95% CI, 90.2%-96.7%), respectively. Regarding cohort assembly, 15,522 patients were identified with diseased carotid artery, including 2674 exhibiting equal bilateral disease. This resulted in a laterality-specific cohort with 12,828 moderate, 5283 severe, and 1895 occluded arteries and 326 diseased arteries with unknown stenosis. During follow-up, 30.1% of these patients underwent 61,107 additional studies. Conclusions Use of NLP to detect carotid stenosis or occlusion can result in accurate exclusion of normal/non-hemodynamically significant stenosis disease states with more moderate precision with lesion identification, which can substantially reduce the need for manual review. The resulting cohort allows for efficient research and holds promise for similar reporting in other vascular diseases.

Objective Previous studies of the natural history of abdominal aortic aneurysms (AAAs) have been limited by small cohort sizes or heterogeneous analyses of pooled data. By quickly and efficiently extracting imaging data from the health records, natural language processing (NLP) has the potential to substantially improve how we study and care for patients with AAAs. The aim of the present study was to test the ability of an NLP tool to accurately identify the presence or absence of AAAs and detect the maximal abdominal aortic diameter in a large dataset of imaging study reports. Methods Relevant imaging study reports (n = 230,660) from 2003 to 2017 were obtained for 32,778 patients followed up in a prospective aneurysm surveillance registry within a large, diverse, integrated healthcare system. A commercially available NLP algorithm was used to assess the presence of AAAs, confirm the absence of AAAs, and extract the maximal diameter of the abdominal aorta, if stated. A blinded expert manual review of 18,000 randomly selected imaging reports was used as the reference standard. The positive predictive value (PPV or precision), sensitivity (recall), and the kappa statistics were calculated. Results Of the randomly selected 18,000 studies that underwent expert manual review, 48.7% were positive for AAAs. In confirming the presence of an AAA, the interrater reliability of the NLP compared with the expert review showed a kappa value of 0.84 (95% confidence interval [CI], 0.83-0.85), with a PPV of 95% and sensitivity of 88.5%. The NLP algorithm showed similar results for confirming the absence of an AAA, with a kappa of 0.79 (95% CI, 0.799-0.80), PPV of 77.7%, and sensitivity of 91.9%. The kappa, PPV, and sensitivity of the NLP for correctly identifying the maximal aortic diameter was 0.88 (95% CI, 0.87-0.89), 88.8%, and 88.2% respectively. Conclusions The use of NLP software can accurately analyze large volumes of radiology report data to detect AAA disease and assemble a contemporary aortic diameter-based cohort of patients for longitudinal analysis to guide surveillance, medical management, and operative decision making. It can also potentially be used to identify from the electronic medical records pre- and postoperative AAA patients “lost to follow-up,” leverage human resources engaged in the ongoing surveillance of patients with AAAs, and facilitate the construction and implementation of AAA screening programs.

Abdominal aortic aneurysm (AAA) may lead to rupture and death if left untreated. While endovascular or surgical repair is generally recommended for AAA greater than 5–5.5 cm, the vast majority of aneurysms detected by screening modalities are smaller than this threshold. Once discovered, there would be a significant potential benefit in suppressing the growth of these small aneurysms in order to obviate the need for repair and mitigate rupture risk. Patients with diabetes, in particular those taking the oral hypoglycaemic medication metformin, have been shown to have lower incidence, growth rate, and rupture risk of AAA. Metformin therefore represents a widely available, non-toxic, potential inhibitor of AAA growth, but thus far no prospective clinical studies have evaluated this. Here, we present the background, rationale, and design for a randomised, double-blind, placebo-controlled clinical trial of metformin for growth suppression in patients with small AAA.

Informed debate regarding the optimal use of carotid endarterectomy (CEA) for stroke risk reduction requires contemporary assessment of both long-term risk and periprocedural risk. In this study, we report long-term stroke and death risk after CEA in a large integrated health care system.All patients with documented severe (70%-99%) stenosis from 2008 to 2012 who underwent CEA were identified and stratified by asymptomatic or symptomatic indication. Those with prior ipsilateral interventions were excluded. Patients were followed up through 2017 for the primary outcomes of any stroke/death within 30 days of intervention and long-term ipsilateral ischemic stroke; secondary outcomes were any stroke and overall survival.Overall, 1949 patients (63.2% male; mean age, 71.3 ± 8.9 years) underwent 2078 primary CEAs, 1196 (58%) for asymptomatic stenosis and 882 (42%) for symptomatic stenosis. Mean follow-up was 5.5 ± 2.7 years. Median time to surgery was 72.0 (interquartile range, 38.5-198.0) days for asymptomatic patients and 21.0 (interquartile range, 5.0-55.0) days for symptomatic patients (P .001). Most of the patients' demographics and characteristics were similar in both groups. Controlled blood pressure rates were similar at the time of CEA. Baseline statin use was seen in 60.5% of the asymptomatic group compared with 39.9% in the symptomatic group (P .001), and statin adherence by 80% medication possession ratio was 19.3% asymptomatic vs 12.4% symptomatic (P .001). The crude overall 30-day any stroke/death rates were 0.9% and 1.5% for the asymptomatic group and the symptomatic group, respectively. The 5-year risk of ipsilateral stroke and a combined end point of any stroke/death by Kaplan-Meier survival analysis were 2.5% and 28.7% for the asymptomatic group and 4.0% and 31.4% for the symptomatic group, respectively. Unadjusted cumulative all-cause survival was 74.2% for the asymptomatic group and 71.8% for the symptomatic group at 5 years.In a contemporary review of CEA, outcomes for either operative indication show low adverse events perioperatively and low long-term stroke risk up to 5 years. These results are well within consensus guidelines and published trial outcomes and should help inform the discussion around optimal CEA use for severe carotid stenosis.

Objective There is considerable controversy about the significance and appropriate treatment of type II endoleaks (T2Ls) after endovascular aneurysm repair (EVAR). We report our long-term experience with T2L management in a large multicenter registry. Methods Between 2000 and 2010, 1736 patients underwent EVAR, and we recorded the incidence of T2L. Primary outcomes were mortality and aneurysm-related mortality (ARM). Secondary outcomes were change in aneurysm sac size, major adverse events, and reintervention. Results During the follow-up (median of 32.2 months; interquartile range, 14.2-52.8 months), T2L was identified in 474 patients (27.3%). There were no late abdominal aortic aneurysm ruptures attributable to a T2L. Overall mortality ( P = .47) and ARM ( P = .26) did not differ between patients with and without T2L. Sac growth (median, 5 mm; interquartile range, 2-10 mm) was seen in 213 (44.9%) of the patients with T2L. Of these patients with a T2L and sac growth, 36 (16.9%) had an additional type of endoleak. Of all patients with T2L, 111 (23.4%) received reinterventions, including 39 patients who underwent multiple procedures; 74% of the reinterventions were performed in patients with sac growth. Reinterventions included lumbar embolization in 66 patients (59.5%), placement of additional stents in 48 (43.2%), open surgical revision in 14 (12.6%), and direct sac injection in 22 (19.8%). The reintervention was successful in 35 patients (31.5%). After patients with other types of endoleak were excluded, no difference in overall all-cause mortality ( P = .57) or ARM ( P = .09) was observed between patients with T2L-associated sac growth who underwent reintervention and those in whom T2L was left untreated. Conclusions In our multicenter EVAR registry, overall all-cause mortality and ARM were unaffected by the presence of a T2L. Moreover, patients who were simply observed for T2L-associated sac growth had aneurysm-related outcomes similar to those in patients who underwent reintervention. Our future work will investigate the most cost-effective ways to select patients for intervention besides sac growth alone.

Objective Registries have been proven useful to assess clinical outcomes, but data entry and personnel expenses are challenging. We developed a registry to track patients undergoing endovascular aortic aneurysm repair (EVAR) in an integrated health care system, leveraging an electronic medical record (EMR) to evaluate clinical practices, device performance, surgical complications, and medium-term outcomes. This study describes the registry design, data collection, outcomes validation, and ongoing surveillance, highlighting the unique integration with the EMR. Methods EVARs in six geographic regions of Kaiser Permanente were entered in the registry. Cases were imported using a screening algorithm of inpatient codes applied to the EMR. Standard note templates containing data fields were used for surgeons to enter preoperative, postoperative, and operative data as part of normal workflows in the operating room and clinics. Clinical content experts reviewed cases and entered any missing data of operative details. Patient comorbidities, aneurysm characteristics, implant details, and surgical outcomes were captured. Patients entered in the registry are followed up for life, and all relevant events are captured. Results Between January 2010 and June 2013, 2112 procedures were entered in the registry. Surgeon compliance with data entry ranges from 60% to 90% by region but has steadily increased over time. Mean aneurysm size was 5.9 cm (standard deviation, 1.3). Most patients were male (84%), were hypertensive (69%), or had a smoking history (79%). The overall reintervention rate was 10.8%: conversion to open repair (0.9%), EVAR revision (2.6%), other surgical intervention (7.3%). Of the reinterventions, 27% were for endoleaks (I, 34.3%; II, 56.9%; III, 8.8%; IV and V, 0.0%), 10.5% were due to graft malfunction, 3.4% were due to infection, and 2.3% were due to rupture. Conclusions Leveraging an EMR provides a robust platform for monitoring short-term and midterm outcomes after abdominal aortic aneurysm repair. Use of standardized templates in the EMR allows data entry as part of normal workflow, improving compliance, accuracy, and data capture using limited but expert personnel. Assessment of patient demographics, device performance, practice variation, and postoperative outcomes benefits clinical decision-making by providing complete and adjudicated event reporting. The findings from this large, community-based EVAR registry augment other studies limited to perioperative and short-term outcomes or small patient cohorts.

Objective Prior reports have suggested unfavorable outcomes after endovascular aortic aneurysm repair (EVAR) performed outside of the recommended instructions for use (IFU) guidelines. We report our long-term EVAR experience in a large multicenter registry with regard to adherence to IFU guidelines. Methods Between 2000 and 2010, 489 of 1736 patients who underwent EVAR had preoperative anatomic measurements obtained from the M2S, Inc, imaging database (West Lebanon, NH). We examined outcomes in these patients with regard to whether they had met the device-specific IFU criteria. Primary outcomes were all-cause mortality and aneurysm-related mortality. Secondary outcomes were endoleak status, adverse events, reintervention, and aneurysm sac size change. Results The median follow-up for the 489 patients was 3.1 years (interquartile range, 1.6-5.0 years); 58.1% (n = 284) had EVAR performed within IFU guidelines (IFU-adherent group), and 41.9% (n = 205) had EVAR performed outside of IFU guidelines (IFU-nonadherent group). Preoperative anatomic data showed that 62.4% of the IFU-nonadherent group had short neck length, 10.2% had greater angulation than recommended, 7.3% did not meet neck diameter criteria, and 20% had multiple anatomic issues. A small portion (n = 49; 10%) of the 489 patients were lost to follow-up because of leaving membership enrollment (n = 28), moving outside the region (n = 10), or discontinuing image surveillance (n = 11). There was no significant difference in any of the primary or secondary outcomes between the IFU-adherent and IFU-nonadherent groups. Aneurysm sac size change at any time point during follow-up also did not differ significantly between the two groups. A Cox proportional hazard model showed that IFU nonadherence was not predictive of all-cause mortality (hazard ratio, 1.0; P = .91). Similarly, IFU nonadherence was not identified as a risk factor for aneurysm-related mortality or adverse events in stepwise Cox proportional hazards models. Conclusions In our cohort of EVAR patients with detailed preoperative anatomic information and long-term follow-up, overall mortality and aneurysm-related mortality were unaffected by IFU adherence. In addition, rates of endoleak and reintervention after initial EVAR were similar, suggesting that lack of IFU-based anatomic suitability was not a driver of outcomes.

Background Endovascular aneurysm repair (EVAR) has become the standard of care for abdominal aortic aneurysm (AAA), but questions remain regarding the benefit in high-risk and elderly patients. The purpose of this study was to examine the effect of age, preoperative AAA diameter, and their interaction on survival and reintervention rates after EVAR. Methods Our integrated health system's AAA endograft registry was used to identify patients who underwent elective EVAR between 2010 and 2014. Of interest was the effect of patient age at the time of surgery (≤80 vs. >80 years old), preoperative AAA diameter (≤5.5 cm vs. >5.5 cm), and their interaction. Primary endpoints were all-cause mortality and reintervention. Between-within mixed-effects Cox models with propensity score weights were fit. Results Of 1,967 patients undergoing EVAR, unadjusted rates for survival at 4 years after EVAR was 76.1%, and reintervention-free rate was 86.0%. For mortality, there was insufficient evidence for an interaction between age and AAA size (P = 0.309). Patient age >80 years was associated with 2.53-fold higher mortality risk (hazard ratios [HR] = 2.53; 95% confidence intervals [CI], 1.73–3.70; P 5.5 cm was associated with 1.75-fold higher mortality risk (HR = 1.75; 95% CI, 1.26–2.45; P = 0.001). For reintervention risk, there were no significant interactions or main effects for age or AAA diameter. Conclusions Age and AAA diameter are independent predictors of reduced survival after EVAR, but the effect is not amplified when both are present. Age >80 years or AAA size >5.5 cm did not increase the risk of reintervention. No specific AAA size, patient age, or combination thereof was identified that would contraindicate AAA repair.

Background Common femoral artery (CFA) endarterectomy with iliac stenting or stent grafting can be an alternative to traditional open surgery in patients with aortoiliac occlusive disease. We report the long-term outcomes of this approach. Methods Patients undergoing CFA endarterectomy with simultaneous iliac stenting/stent grafting between 1997 and 2006 were retrospectively reviewed. Technical success, clinical and hemodynamic outcomes, and 5-year patency using life-table methodology were determined. Factors associated with reintervention and mortality were determined by logistic regression analysis. Results A total of 171 patients (mean age, 67 ± 10 years; 38% female; 35% diabetic) underwent 193 CFA endarterectomies and iliac stent/stent grafting. Indications were rest pain (32%), tissue loss (22%), and claudication (46%). External iliac artery (EIA) lesions were present in 39%, and combined common iliac artery (CIA) and EIA lesions were seen in 61% of patients. Complete CIA/EIA occlusions were present in 41% of patients. Stent grafts were used in 41% of patients. Technical success occurred in 98% of patients. Clinical improvement was seen in 92% of patients. Mean ankle-brachial index increased from 0.38 ± 0.32 to 0.72 ± 0.24. Median length of stay was 2 days (range, 1-51 days). Thirty-day mortality was 2.3% and 5-year survival was 60%. Five-year primary, primary-assisted, and secondary patencies were 60%, 97%, and 98% respectively. Endovascular reintervention was required in 14% of patients; inflow surgical procedures were required in 10%. By logistic regression analysis, use of stent grafts compared with bare stents was associated with significantly higher primary patency (87% ± 5% vs 53% ± 7%; P Conclusion Combined CFA endarterectomy with iliac intervention yield acceptable long-term results. The use of stent grafts compared with bare stents is associated with improved primary patency.

Objective/Summary Background Data: Serial transverse enteroplasty (STEP) is a new intestinal lengthening procedure that has been shown to clinically increase bowel length. This study examined the impact of the STEP procedure upon intestinal function in a model of short bowel syndrome. Methods: Young pigs (n 10) had a reversed segment of bowel interposed to induce bowel dilatation. Five pigs underwent a 90% bowel resection with a STEP procedure on the remaining dilated bowel while 5 served as controls and had a 90% bowel resection without a STEP procedure. Determinations of nutritional status, absorptive capacity, and bacterial overgrowth were conducted 6 weeks after resection. Statistical comparisons were made by 2-sample t test (significance at P 0.05). Results: The STEP procedure lengthened the bowel from 105.2 7.7 cm to 152.2 8.3 cm (P 0.01). The STEP animals showed improved weight retention compared with controls (mean, 0.5% 1.8% body weight versus 17.6% 1.5%, P 0.001). Intestinal carbohydrate absorption, as measured by D-Xylose absorption and fat absorptive capacity as measured by serum vitamin D and triglyceride levels, were increased in the STEP group versus controls. Serum citrulline, a marker of intestinal mucosal mass, was significantly elevated in the STEP pigs compared with controls. None of the STEP animals but 4 of 5 control animals were noted to have gram-negative bacterial overgrowth in the proximal bowel. Conclusions: STEP improves weight retention, nutritional status, intestinal absorptive capacity, and serum citrulline levels in a porcine short bowel model. A salutary effect upon bacterial overgrowth was also noted. These data support the use of this operation in short bowel syndrome.

Vascular endothelial growth factor (VEGF) is upregulated in pulmonary alveolarization. However, developmental expression of pulmonary VEGF and its possible role in the pathogenesis of CDH are not well described.Timed-pregnant VEGF-LacZ mice, possessing a beta-galactosidase reporter introduced into the 3' region of the VEGF gene, were used to examine fetal lung gene expression in a model of nitrofen-induced CDH.VEGF gene expression increased from embryonic day 13 until its peak at embryonic day 16 and then decreased until term in all groups. This pattern was most apparent in the periphery with smaller differences noted in central lung locations. Expression of VEGF/beta-gal in the lungs of nitrofen-treated mice was less than controls at all time-points (P.0001) The type-II pneumocyte population did not significantly differ between the groups. Study concentrations of nitrofen showed no effect on vascular endothelial proliferation in vitro.Nitrofen downregulates the production of VEGF during gestation and attenuates the peak seen at the onset of the canalicular stage, despite preservation of type-II pneumocytes. This effect was most pronounced in peripheral lung tissue. The authors speculate that altered VEGF expression may have a pivotal role in the pathogenesis of nitrofen-induced CDH.

ObjectiveTo assess outcomes after endovascular abdominal aortic aneurysm repair (EVAR) in an integrated health care system.MethodsBetween 2000 and 2010, 1736 patients underwent EVAR at 17 centers. Demographic data, comorbidities, and outcomes of interest were collected. EVAR in patients presenting with ruptured or symptomatic aneurysms was categorized as urgent; otherwise, it was considered elective. Primary outcomes were mortality and aneurysm-related mortality (ARM). Secondary outcomes were change in aneurysm sac size, endoleak status, major adverse events, and reintervention.ResultsOverall, the median age was 76 years (interquartile range, 70-81 years), 86% were male, and 82% were Caucasian. Most cases (93.8%) were elective, but urgent use of EVAR increased from 4% in the first 5 years to 7.3% in the last 5 years of the study period. Mean aneurysm size was 5.8 cm. Patients were followed for an average of 3 years (range, 1-11 years); 8% were lost to follow-up. Intraoperatively, 4.5% of patients required adjunctive maneuvers for endoleak, fixation, or flow-limiting issues. The 30-day mortality rate was 1.2%, and the perioperative morbidity rate was 6.6%. Intraoperative type I and II endoleaks were uncommon (2.3% and 9.3%, respectively). Life-table analysis at 5 years demonstrated excellent overall survival (66%) and freedom from ARM (97%). Postoperative endoleak was seen in 30% of patients and was associated with an increase in sac size over time. Finally, the total reintervention rate was 15%, including 91 instances (5%) of revisional EVAR. The overall major adverse event rate was 7.9% and decreased significantly from 12.3% in the first 5 years to 5.6% in the second 5 years of the study period (P < .001). Overall ARM was worse in patients with postoperative endoleak (4.1% vs 1.8%; P < .01) or in those who underwent reintervention (7.6% vs 1.6%; P < .001).ConclusionsResults from a contemporary EVAR registry in an integrated health care system demonstrate favorable perioperative outcomes and excellent clinical efficacy. However, postoperative endoleak and the need for reintervention continue to be challenging problems for patients after EVAR.

Background/Purpose Previous work has shown that intrapulmonary delivery of oncotic agents enhance overall lung growth after late gestational fetal tracheal occlusion (TO). This study was a post hoc analysis aimed at determining whether actual alveolar and capillary hyperplasias are maximized in this setting. Methods Twenty-one near term fetal lambs were evenly divided into 4 groups: group I comprised sham-operated controls; group II had TO alone; and groups III and IV underwent TO and intratracheal infusion of equal amounts of either saline or 25% albumin, respectively. Approximately 2 weeks thereafter, their lungs were examined by detailed alveolar and capillary morphometry before birth. Statistical analysis included analysis of variance and the Bonferroni correction for multiple comparisons ( P Results Total alveolar and capillary numbers, as well as total alveolar surface area, were significantly higher in group IV and lower in group I compared with all other groups, with no differences between groups II and III. Alveolar capillary load was normal in all groups. Conclusions Intrapulmonary delivery of concentrated albumin safely enhances short-term alveolar and capillary hyperplasia in a late gestational model of fetal TO. This therapeutic concept may allow for TO to be effective and predictable when performed late in gestation.

Background/purpose This study examined whether an injectable hydrogel could buttress the balloon used in fetal tracheal occlusion, thus preventing its displacement. Methods Fetal lambs (n = 11) underwent tracheal occlusion through local delivery of a detachable silicone balloon and were divided in 2 groups: group I had no further manipulations, and group II received an intratracheal injection of a rapidly polymerizing hydrogel, cranially to the balloon. Near term, balloon placement was examined, the lung volume—to—body weight ratio (LV:BW) was determined, and tracheal histology was performed. Statistical analysis was by the Fisher's Exact test, with significance set at P Results Complete tracheal occlusion was achieved in all fetuses intraoperatively. The rate of balloon dislodgement was significantly higher in group I (4 of 7, or 57.1%) than in group II (0 of 4). In group II, balloons were recovered in situ with a column of residual hydrogel reinforcing their cephalad position. Animals in which balloon occlusion was maintained had significantly higher LV:BW, with no evidence of tracheal damage. Conclusions Intratracheal delivery of a rapidly polymerizing hydrogel cephalad to detachable silicone balloons results in improved fetal tracheal occlusion, with no harmful effects to the trachea. This adjuvant principle may enhance minimally invasive balloon tracheal occlusion for treatment of severe fetal pulmonary hypoplasia.

Background/purpose This study was aimed at comparing albumin and dextran as intrapulmonary hyperoncotic enhancers of fetal lung growth after tracheal occlusion. Methods Fetal lambs (n = 27) were divided proportionally into 5 groups: group I consisted of sham-operated controls; group II underwent tracheal occlusion (TO); groups III, IV, and V underwent TO and intratracheal infusion of 60 mL of either saline, 6% dextran-70, or 25% albumin, respectively. Multiple fetal lung analyses were performed near term. Statistical analysis was by 1-way analysis of variance (ANOVA) and post-hoc analyses by the Bonferroni correction for multiple comparisons ( P Results The lung volume-to-body weight ratio was significantly higher in groups IV and V than in all other groups with no differences between groups II and III, nor between groups IV and V. Airspace fraction was not significantly different among the groups, nor was there any evidence of alveolar cellular damage. Type-II pneumocyte density was higher in group I than in groups II, IV, and V, with no differences among the latter 3 groups. Lung liquid biochemical profile was normal in all groups. Conclusions Albumin is as effective as dextran as an intrapulmonary hyperoncotic booster of lung growth acceleration after fetal tracheal occlusion, with no lasting effects on its fetal lung liquid levels. As a naturally occurring oncotic agent, albumin may be a safer option in the clinical application of this therapeutic concept.

Purpose: Preliminary studies have shown aminocaproic acid (AMICAR), an inhibitor of fibrinolysis, reduced the incidence of intracranial hemorrhage and significant surgical site bleeding in patients on extracorporeal membrane oxygenation (ECMO). The purpose of this analysis is to determine if these benefits remain when AMICAR is used in a large population. Methods: ECMO patients from a single pediatric institution, with routine use of AMICAR for "high-risk" patients, were evaluated retrospectively from 1991 to 2001. Data including diagnosis, duration of support, significant complications, and survival were recorded. These variables were compared with those of the Extracorporeal Life Support Organization (ELSO), an international ECMO registry, using a χ 2 test. P less than .05 was deemed significant. Results: ECMO was used 431 times during the 10-year study period. A total of 298 patients received AMICAR, most frequently for surgical procedures. The survival rate was not statistically different in the study group when compared with the ELSO Registry ( P = .06). The rate of neonatal intracranial hemorrhage was not significantly different between the 2 groups ( P = .133); however, the rate of surgical site bleeding was significantly reduced in the study population ( P = .005). Decrease in surgical site bleeding was particularly evident in cardiac patients ( P Conclusions: In this large experience, use of AMICAR for high-risk patients on ECMO did not appear to alter the rate of neonatal intracranial hemorrhage, but did significantly reduce the incidence of surgical site bleeding. AMICAR remains a valuable tool for the prevention of hemorrhage in patients undergoing operation prior to or while on ECMO.

Adherence to EVAR Device Instructions for Use (IFU) Guidelines Has No Impact on Long-Term Outcomes Joy P. Walker, MD, Lue-Yen Tucker, Philip Goodney, Hong Hua, Steven Okuhn, Ann Rhoades, Bradley Hill, Robert W. Chang. Vascular and Endovascular Surgery, University of California San Francisco, San Francisco, Calif; Kaiser Permanente Division of Research, Oakland, Calif; Dartmouth-Hitchcock Medical Center, Lebanon, NH; The Permanente Medical Group, San Francisco, Calif; Kaiser Permanente, Oakland, Calif; The Permanente Medical Group, Santa Clara, Calif; The Permanente Medical Group, South San Francisco, Calif