Vascular Anastomoses and Dissection: A Six-Part Simulation Curriculum for Surgical Residents.

Introduction: As surgical technologies grow, so too do demands on surgical trainees to master increasing numbers of skill sets. With the rise of endovascular surgery, trainees have fewer opportunities to practice open vascular techniques in the operating room. Simulation can bridge this gap. However, existing published open vascular simulation curricula are basic or based on expensive models. Methods: We iteratively developed an open vascular skills curriculum for second-year surgery residents comprising six 2-hour sessions. We refined the curriculum based on feedback from learners and faculty. The curriculum required skilled facilitators, vascular instruments, and tissue models. We evaluated the latest iteration with a survey and by assessing participants' technical skills using the Objective Structured Assessment of Technical Skills (OSATS) form. Results: Over the past 10 years, 101 residents have participated in the curriculum. Nine of 13 residents who participated in the latest curricular iteration completed the survey. All respondents rated the sessions as excellent and strongly agreed that they had improved their abilities to perform anastomoses with tissue and prosthetic. Facilitators completed 18 OSATS forms for residents in the fifth and sixth sessions of the latest iteration. Residents scored well overall, with a median 26.5 (interquartile range: 24-29) out of a possible score of 35, with highest scores on knowledge of instruments. Discussion: This simulation-based curriculum facilitates open vascular surgical skill acquisition among surgery residents. The curriculum allows residents to acquire critical vascular skills that are challenging to learn in an increasingly demanding operative setting.

Assessment of Surgeon Performance of Advanced Open Surgical Skills Using a Microskills-Based Novel Curriculum.

Importance: The increase in minimally invasive surgical procedures has eroded exposure of general surgery residents to open operations. High-fidelity simulation, together with deliberate instruction, is needed for advanced open surgical skill (AOSS) development. Objective: To collect validity evidence for AOSS tools to support a shared model for instruction. Design, Setting, and Participants: This prospective cohort study included postresidency surgeons (PRSs) and second-year general surgery residents (R2s) at a single academic medical center who completed simulated tasks taught within the AOSS curriculum between June 1 and October 31, 2021. Exposures: The AOSS curriculum includes 6 fine-suture and needle handling tasks, including deep suture tying (with and without needles) and continuous suturing using the pitch-and-catch and push-push-pull techniques (both superficial and deep). Teaching and assessment are based on specific microskills using a 3-dimensional printed iliac fossa model. Main Outcomes and Measures: The PRS group was timed and scored (5-point Likert scale) on 10 repetitions of each task. Six months after receiving instruction on the AOSS tasks, the R2 group was similarly timed and scored. Results: The PRS group included 14 surgeons (11 male [79%]; 8 [57%] attending surgeons) who completed the simulation; the R2 group, 9 surgeons (5 female [55%]) who completed the simulation. Score and time variability were greater for the R2s compared with the PRSs for all tasks. The R2s scored lower and took longer on (1) deep pitch-and-catch suturing (69% of maximum points for a mean [SD] of 142.0 [31.7] seconds vs 77% for a mean [SD] of 95.9 [29.4] seconds) and deep push-push-pull suturing (63% of maximum points for a mean [SD] of 284.0 [72.9] seconds vs 85% for a mean [SD] of 141.4 [29.1] seconds) relative to the corresponding superficial tasks; (2) suture tying with a needle vs suture tying without a needle (74% of maximum points for a mean [SD] of 64.6 [19.8] seconds vs 90% for a mean [SD] of 54.4 [15.6] seconds); and (3) the deep push-push-pull vs pitch-and-catch techniques (63% of maximum points for a mean [SD] of 284.0 [72.9] seconds vs 69% of maximum points for a mean [SD] of 142.0 [31.7] seconds). For the PRS group, time was negatively associated with score for the 3 hardest tasks: superficial push-push-pull (ρ = 0.60; P = .02), deep pitch-and-catch (ρ = 0.73; P = .003), and deep push-push-pull (ρ = 0.81; P < .001). For the R2 group, time was negatively associated with score for the 2 easiest tasks: suture tying without a needle (ρ = 0.78; P = .01) and superficial pitch-and-catch (ρ = 0.79; P = .01). Conclusions and Relevance: The findings of this cohort study offer validity evidence for a novel AOSS curriculum; reveal differential difficulty of tasks that can be attributed to specific microskills; and suggest that position on the surgical learning curve may dictate the association between competency and speed. Together these findings suggest specific, actionable opportunities to guide instruction of AOSS, including which microskills to focus on, when individual rehearsal vs guided instruction is more appropriate, and when to focus on speed.

Eptifibatide bridging therapy for staged carotid artery stenting and cardiac surgery: Safety and feasibility.

BACKGROUND: Prophylactic carotid artery stenting (CAS) is an effective strategy to reduce perioperative stroke in patients with severe carotid stenosis who require cardiothoracic surgery (CTS). Staging both procedures (CAS-CTS) during a single hospitalization presents conflicting demands for antiplatelet therapy and the optimal pharmacologic strategy between procedures is not established. The purpose of this study is to present our initial experience with a "bridging" protocol for staged CAS-CTS. METHODS: A retrospective review of staged CAS-CTS procedures at a single referral center was performed. All patients had multivessel coronary and/or valvular disease and severe carotid stenosis (>70%). Patients not previously on aspirin were also started on aspirin prior to surgery, followed by eptifibatide during CAS (intraprocedural bolus followed by post-procedural infusion which was continued until the morning of surgery). Pre- and perioperative (30 days) neurologic morbidity and mortality was the primary endpoint. RESULTS: 11 CAS procedures were performed in 10 patients using the protocol. The median duration of eptifibatide bridge therapy was 36 h (range 24-288 h). There was one minor bleeding complication (1/11, 9.1%) and no major bleeding complications during the bridging and post-operative period. There was one post-operative, non-neurologic death and zero perioperative ischemic strokes. CONCLUSIONS: For patients undergoing staged CAS-CTS, Eptifibatide bridging therapy is a viable temporary antiplatelet strategy with a favorable safety profile. This strategy enables a flexible range of time-intervals between procedures.

Mild anemia as a single independent predictor of mortality in patients with COVID-19.

The coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led to an unprecedented international health crisis. COVID-19 clinical presentations cover a wide range from asymptomatic to severe illness and death. Given the limited therapeutic resources and unexpected clinical features of the disease, readily accessible predictive biomarkers are urgently needed to improve patient care and management. We asked the degree to which anemia may influence the outcome of patients with COVID-19. To this end, we identified 3777 patients who were positively diagnosed with COVID-19 between March 1 and April 1 2020 in New York City. We evaluated 2,562 patients with available red blood cell, hemoglobin, and related laboratory values. Multivariable cox proportional hazards regression showed that anemia was a significant independent predictor of mortality (hazard ratio (HR): 1.26, 95% Confidence Interval [CI]: 1.06-1.51), independent of age, sex, and comorbidities. There was a direct correlation between the degree of anemia and the risk of mortality when hemoglobin was treated as a continuous variable (HRadj 1.05; [CI]: 1.01-1.09). The hemoglobin level that was maximally predictive of mortality, was 11.5 g/dL in males and 11.8 g/dL in females. These findings identify a routinely measured biomarker that is predictive of disease outcomes and will aid in refining clinical care algorithms and optimize resource allocation. Mechanisms of impacts of anemia on COVID-19 outcome are likely to be multiple in nature and require further investigation.

Post-9/11 excess risk of thyroid cancer: Surveillance or exposure?

An excess risk of thyroid cancer has been reported in different World Trade Center (WTC)-dust exposed cohorts. Increased surveillance of these cohorts has been suggested as a potential explanation of this reported excess thyroid cancer risk leading to an increased diagnosis of earlier-stage thyroid cancers. However, the uncertainty to what extent surveillance or physician bias may be contributing to the reported incidence of thyroid cancer in WTC-dust exposed populations remains, highlighting the need to investigate a potential causal link between WTC dust exposure and thyroid cancer. Future studies are therefore indicated to investigate potential consequences of WTC dust exposure on the thyroid gland. Studies of the heavily exposed populations offer the possibility to better understand the mechanisms behind the exposure to a variety of environmental contaminants, and may provide useful insights into exposures harmful to the thyroid. These can be used in risk stratification when implementing screening in high-risk populations and may inform shared decision-making regarding the extent of thyroid cancer treatment.

Changes in E-Cigarette Perceptions Over Time: A National Youth Tobacco Survey Analysis.

INTRODUCTION: This multiyear, cross-sectional study explores the changes over time in how U.S. middle- and high-school students perceive the harm and addiction risk of E-cigarettes. METHODS: This study analyzed 83,779 participants in the National Youth Tobacco Survey from 2015 to 2019. Associations of survey year with perceived harm and addiction risk of E-cigarettes were assessed using multivariable multinomial logistic regression models, adjusted for sociodemographic characteristics. RESULTS: Smoking decreased over the 5 years (-1.85 percentage points, p=0.07); vaping increased (9.03 percentage points, p<0.01). Perceived harm of both combustible cigarettes and E-cigarettes increased with time. Male, older, and non-White students perceived less harm from smoking or vaping. Perceptions of the addictiveness of E-cigarettes increased over time: 26.31% of students considered E-cigarettes to be more addictive than combustible cigarettes in 2019, compared with 7.26% in 2016. Female and non-White students were more likely to think that E-cigarettes were at least as addictive as combustible cigarettes but also reported less knowledge about them. CONCLUSIONS: The perceptions of both harm and addictiveness of E-cigarettes have increased over time, independent of current use. Perceptions vary on the basis of age, sex, race/ethnicity, and current use. Efforts should be made to further educate adolescents about E-cigarettes and to regulate their sale and advertisement. Efforts to reduce the uptake of combustible cigarettes among adolescents have been successful and should be duplicated for E-cigarettes.

Using Rapid Research Implementation and Collaborations to Assess the Mental Health Impact of the COVID-19 Pandemic Among Community and Clinical Cohorts.

A research initiative was launched during the initial coronavirus disease (COVID-19) outbreak by 3 New York metropolitan area institutions. Collaborators recruited community members and patients from previous research studies to examine COVID-19 experiences and mental health symptoms through self-report surveys. The current report descriptively presents findings from the initial survey characterized by both community and clinical cohorts, and discusses challenges encountered with rapid implementation. The clinical cohort exhibited higher rates of symptoms of mental health difficulties (depression, anxiety, and posttraumatic stress disorder [PTSD]) as compared to the community cohort. COVID-19 positivity rates were similar among both groups and lower than the national average. While both groups reported low rates of job loss, community members reported higher rates of financial difficulty resulting from the pandemic. Findings indicate the need for further collaborative research on the mental health impact of COVID-19.

Clinical Course of Cancer Patients With COVID-19: A Retrospective Cohort Study.

Background: Complications in cancer patients with coronavirus disease 2019 (COVID-19) have not been examined. This analysis aimed to compare characteristics of COVID-19 patients with and without cancer and assess whether cancer is associated with COVID-19 morbidity or mortality. Methods: COVID-19-positive patients with an inpatient or emergency encounter at the Mount Sinai Health System between March 1, 2020, and May 27, 2020, were included and compared across cancer status on demographics and clinical characteristics. Multivariable logistic regressions were used to model the associations of cancer with sepsis, venous thromboembolism, acute kidney injury, intensive care unit admission, and all-cause mortality. Results: There were 5556 COVID-19-positive patients included, 421 (7.6%) with cancer (325 solid, 96 nonsolid). Those with cancer were statistically significantly older, more likely to be non-Hispanic Black and to be admitted to the hospital during their encounter, and had more comorbidities than noncancer COVID-19 patients. Cancer patients were statistically significantly more likely to develop sepsis (adjusted odds ratio [ORadj] = 1.31, 95% confidence interval [CI] = 1.06 to 1.61) and venous thromboembolism (ORadj = 1.77, 95% CI = 1.01 to 3.09); there was no statistically significant difference in acute kidney injury (ORadj = 1.10, 95% CI = 0.87 to 1.39), intensive care unit admissions (ORadj = 1.04, 95% CI = 0.80 to 1.34), or mortality (ORadj = 1.02, 95% CI = 0.81 to 1.29). Conclusions: COVID-19 patients with cancer may have a higher risk for adverse outcomes. Although there was no statistically significant difference in mortality, COVID-19 patients with cancer have statistically significantly higher risk of thromboembolism and sepsis. Further research is warranted into the potential effects of cancer treatments on inflammatory and immune responses to COVID-19 and on the efficacy of anticoagulant therapy in these patients.

Prevalence of Cytopenia in the General Population-A National Health and Nutrition Examination Survey Analysis.

BACKGROUND: Cytopenia, a reduced count of blood cells manifesting as anemia, neutropenia, and/or thrombocytopenia is frequently associated with other medical conditions. However, a cytopenia may not be accompanied by a known determinant and in some of these cases, may be a precursor to pre-malignancies or hematologic cancers. Little is known about the prevalence of these unexplained cytopenias and their distribution in the population. MATERIALS AND METHODS: The National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002 was used to identify those with a cytopenia in the general population. Those without an identifiable determinant in the NHANES were classified as having unexplained cytopenia. Weighted frequencies were examined to assess the prevalence of unexplained cytopenia in the population. Distribution of blood counts comparing those with unexplained cytopenia to the general population was examined. Multivariable logistic regression was conducted to assess the association between unexplained cytopenia and demographic factors. RESULTS: Of the 7,962 people in the sample, 236 (2.0%) had any cytopenia and 86 (0.9%) had an unexplained cytopenia. Approximately 43% of all cytopenias were not accompanied by a clinical determinant. Unexplained cytopenia was more common in men (1.1%) than in women (0.7%) and in Non-Hispanic Black participants (3.4%). Among those with an unexplained cytopenia, the majority (74.8%) manifested as neutropenia. Compared to those with no cytopenia, those with unexplained cytopenia were significantly less likely to be female, have body mass index ≥30 kg/m2, and work in the service industry, and were significantly more likely to be non-Hispanic Black. CONCLUSIONS: This is the first study to examine the prevalence of unexplained cytopenia in a nationally representative sample and may serve as a baseline for comparison with other populations. Future research to identify risk factors for development of malignant hematological disorders among those with unexplained cytopenia is warranted.

Disparities in Surgical Recommendation for Stage I Non-Small Cell Lung Cancer.

OBJECTIVES: Sociodemographic disparities in lung cancer prevalence, treatment options offered, and outcomes have been well documented. In stage I non-small cell lung cancer (NSCLC), the standard of care is surgical resection. This study explores disparities in surgical recommendations in stage I NSCLC, when surgery is considered curative. MATERIALS AND METHODS: Patients diagnosed with primary stage I NSCLC from 2007 to 2016 were identified from the Surveillance, Epidemiology, and End Results database (N=56,534). Associations between sociodemographic variables and surgical recommendation were assessed using multivariable logistic regression models. Survival impact was investigated using Cox-proportional hazards regression and propensity matching techniques. RESULTS: Of the 76.9% patients recommended surgery, 95% underwent surgery. Recommended surgery was inversely associated with increasing age (P<0.01), non-Hispanic Black race (adjusted odds ratio [ORadj] 0.64, 95% confidence interval [CI]: 0.59-0.70), Hispanic ethnicity (ORadj 0.75, 95% CI: 0.67-0.84), nonprivate/Medicare insurance (Medicaid: ORadj 0.55, 95% CI: 0.51-0.60; insured with unknown plan: ORadj 0.74, 95% CI: 0.69-0.79; uninsured: ORadj 0.45, 95% CI: 0.36-0.55), and single status (ORadj 0.66, 95% CI: 0.63-0.70). Patients who were not recommended surgery were at increased risk of death compared with those who were recommended. CONCLUSION: In a cohort of NSCLC patients, nonclinical factors identified a subgroup of patients who were less likely to be recommended surgery.

Serum cotinine levels and nicotine addiction potential of e-cigarettes: an NHANES analysis.

This study aims to compare serum cotinine levels in e-cigarette and combustible cigarette smokers, in an attempt to quantify the potential chronic nicotine addiction risk that e-cigarettes pose. We analyzed 428 participants in 2015-2016 NHANES: 379 (87.03%) smoked combustible cigarettes alone and 49 (12.97%) smoked e-cigarettes. Serum cotinine levels were measured by isotope-dilution high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method with a detection limit of 0.015 ng/ml. Electronic cigarette smokers were younger than combustible cigarette smokers (mean age 36.79 versus 42.69 years, P = 0.03), more likely to be male (64.93% versus 48.32%, P = 0.09) and significantly less likely to live with other smokers (50.17% versus 90.07%, P < 0.01). Serum cotinine levels increased linearly with self-reported days of smoking in both electronic cigarette and combustible cigarette smokers, after accounting for living with a smoker. The analysis of the subgroup who reported daily use show non-statistically significantly higher serum cotinine levels in electronic cigarette smokers versus combustible cigarette smokers (ß adj = 52.50, P = 0.10). This analysis of recent US data demonstrates that electronic cigarettes expose users to nicotine levels proportionate to, and potentially higher than combustible cigarettes, and thus pose a serious risk of chronic nicotine addiction. This could be particularly relevant in otherwise tobacco naive individuals; future risk of tobacco-related dependence, addiction and relapse, as well as of tobacco-related cancers in these subjects needs to be investigated.

Disparities in surgery for early-stage cancer: the impact of refusal.

BACKGROUND: For early-stage cancer surgery is often curative, yet refusal of recommended surgical interventions may be contributing to disparities in patient treatment. This study aims to assess predictors of early-stage cancers surgery refusal, and the impact on survival. METHODS: Patients recommended surgery with primary stage I and II lung, prostate, breast, and colon cancers, diagnosed between 2007-2014, were identified in the Surveillance, Epidemiology and End Results database (n = 498,927). Surgery refusal was reported for 5,757 (1.2%) patients. Associations between sociodemographic variables and surgery refusal by cancer type were assessed in adjusted multivariable logistic regression models. The impact of refusal on survival was investigated using adjusted Cox-Proportional Hazard regression in a propensity score-matched cohort. RESULTS: Increasing age (p < 0.0001 for all four cancer types), non-Hispanic Black race/ethnicity (ORadjBREAST 2.00, 95% CI 1.68-2.39; ORadjCOLON 3.04, 95% CI 2.17-4.26; ORadjLUNG 2.19, 95% CI 1.77-2.71; ORadjPROSTATE 2.02, 95% CI 1.86-2.20; vs non-Hispanic White), insurance status (uninsured: ORadjBREAST 2.75, 95% CI 1.89-3.99; ORadjPROSTATE 2.10, 95% CI 1.72-2.56; vs insured), marital status (ORadjBREAST 2.16, 95% CI 1.85-2.51; ORadjCOLON 1.56, 95% CI 1.16-2.10; ORadjLUNG 2.11, 95% CI 1.80-2.47; ORadjPROSTATE 1.94, 95% CI 1.81-2.09), and stage (ORadjBREAST 1.94, 95% CI 1.70-2.22; ORadjCOLON 0.13, 95% CI 0.09-0.18; ORadjLUNG 0.71, 95% CI 0.52-0.96) were all associated with refusal; patients refusing surgery were at increased risk of death compared to patients who underwent surgery. CONCLUSIONS: More vulnerable patients are at higher risk of refusing recommended surgery, and this decision negatively impacts their survival.

Vascular inflammation in a growing iliac artery aneurysm.

We have used a multimodality imaging approach to assess the inflammatory component of a growing iliac artery aneurysm in a 53-year-old man who presented with related ureteral obstruction. Research suggests that episodic and heterogeneous inflammatory processes are important for the progression of aneurysms. The combined PET and MRI evaluation of inflammation that we present here is a novel approach to vascular imaging that is well suited for emerging hybrid PET/MRI systems.

Ferumoxytol-enhanced magnetic resonance angiography is a feasible method for the clinical evaluation of lower extremity arterial disease.

BACKGROUND: Renal toxicity from conventional, iodinated, intravenous contrast agents is a common complication in patients with peripheral artery disease (PAD). Similarly, the potential for serious side effects prevents the use of gadolinium-based agents in many patients with depressed renal function. Ferumoxytol-enhanced magnetic resonance angiography (Fe-MRA) is a novel technique that uses an intravenous, ultrasmall, superparamagnetic, iron oxide preparation, currently approved by the Food and Drug Administration for the treatment of iron deficiency anemia in adults with chronic kidney disease. Our objective was to determine the feasibility of Fe-MRA for clinical decision making in PAD patients. METHODS: This was a prospective pilot study assessing 10 patients with suspected arterial occlusive disease with contrast-enhanced MRA of the aorta and lower extremities. Of those, 5 had renal insufficiency and were imaged with Fe-MRA, whereas the remainder underwent gadolinium-enhanced MRA. Qualitative and quantitative evaluations of deidentified images at each arterial station were independently performed by 4 blinded vascular surgeons. RESULTS: All patients were men, with an average age of 68 ± 4 years. The 2 groups had similar incidences of diabetes, hypertension, hyperlipidemia, and coronary artery disease. Patients undergoing Fe-MRA had significantly decreased renal function (estimated glomerular filtration rate, 35.4 vs. 77.6; P = 0.02). There were no adverse events during contrast administration in either group. No difference was found in the overall quality of the ferumoxytol versus the gadolinium studies (7.1 ± 2.0 vs. 7.4 ± 2.4, P = 0.67). Similarly, reviewers felt comfortable basing clinical decisions on the images 89% of the time with both the ferumoxytol and gadolinium groups (P = 1.00). CONCLUSIONS: This is the first report of an important alternative to conventional computed tomography angiography and MRA in PAD patients, particularly in the setting of renal insufficiency. Fe-MRA provides a useful tool in patients with suspected lower extremity PAD without the potential risks of gadolinium.

Vitamin D deficiency is associated with mortality and adverse vascular access outcomes in patients with end-stage renal disease.

BACKGROUND: Plasma 25 hydroxycholecalciferol (vitamin D) deficiency has been associated with adverse cardiovascular outcomes in epidemiologic studies. Chronic kidney disease is associated with loss of 1α-hydroxylase and consequently vitamin D deficiency. We hypothesized that vitamin D deficiency was associated with increased mortality and increased vascular access failure in patients undergoing permanent vascular access for end-stage renal disease. METHODS: This retrospective cohort study analyzed 128 patients undergoing permanent vascular access surgery between 2003 and 2012 for whom concurrent plasma vitamin D levels were also available. Levels were considered deficient at <20 ng/mL. Multivariable analysis was used to determine the association between vitamin D and mortality and vascular access outcomes. RESULTS: The mean age was 66.7 years, 96.8% were male, 32.0% were African American, and 60.9% had diabetes mellitus. In the entire cohort, 55.5% were vitamin D-deficient, despite similar rates of repletion among the vitamin D-deficient and nondeficient groups. During a median follow-up of 2.73 years, there were 40 deaths (31%). Vitamin D-deficient patients tended to be younger (P = .01) and to have higher total cholesterol (P = .001) and lower albumin (P = .017) and calcium (P = .007) levels. Despite their younger age, mortality was significantly higher (P = .026) and vascular access failure was increased (P = .008) in the vitamin D-deficient group. Multivariate logistic regression analysis found vitamin D deficiency (odds ratio [OR], 3.64; 95% confidence interval [CI], 1.12-11.79; P = .031), hemodialysis through a central catheter (OR, 3.08; 95% CI, 1.04-9.12; P = .042), coronary artery disease (OR, 3.08; 95% CI, 1.06-8.94; P = .039), increased age (OR, 1.09; 95% CI, 1.03-1.15; P = .001), and albumin (OR, 0.27; 95% CI, 0.09-0.83; P = .023) remained independent predictors of mortality. Vitamin D deficiency (hazard ratio [HR], 2.34; 95% CI, 1.17-4.71; P = .02), a synthetic graft (HR, 3.50; 95% CI, 1.38-8.89; P = .009), and hyperlipidemia (HR, 0.42; 95% CI, 0.22-0.81; P = .01) were independent predictors of vascular access failure in a Cox proportional hazard model. CONCLUSIONS: Vitamin D deficiency is highly prevalent in patients undergoing vascular access procedures. Patients who are deficient in vitamin D have worse survival and worse vascular access outcomes. Further study is warranted to assess whether aggressive vitamin D repletion will improve outcomes in this population.

Inducible ApoE gene repair in hypomorphic ApoE mice deficient in the low-density lipoprotein receptor promotes atheroma stabilization with a human-like lipoprotein profile.

OBJECTIVE: To study atherosclerosis regression in mice after plasma lipid reduction to moderately elevated apolipoprotein B (apoB)-lipoprotein levels. APPROACH AND RESULTS: Chow-fed hypomorphic Apoe mice deficient in low-density lipoprotein receptor expression (Apoe(h/h)Ldlr(-/-)Mx1-cre mice) develop hyperlipidemia and atherosclerosis. These mice were studied before and after inducible cre-mediated Apoe gene repair. By 1 week, induced mice displayed a 2-fold reduction in plasma cholesterol and triglyceride levels and a decrease in the non-high-density lipoprotein:high-density lipoprotein-cholesterol ratio from 87%:13% to 60%:40%. This halted atherosclerotic lesion growth and promoted macrophage loss and accumulation of thick collagen fibers for up to 8 weeks. Concomitantly, blood Ly-6C(high) monocytes were decreased by 2-fold but lesional macrophage apoptosis was unchanged. The expression of several genes involved in extracellular matrix remodeling and cell migration was changed in lesional macrophages 1 week after Apoe gene repair. However, mRNA levels of numerous genes involved in cholesterol efflux and inflammation were not significantly changed at this time point. CONCLUSIONS: Restoring apoE expression in Apoe(h/h)Ldlr(-/-)Mx1-cre mice resulted in lesion stabilization in the context of a human-like ratio of non-high-density lipoprotein:high-density lipoprotein-cholesterol. Our data suggest that macrophage loss derived in part from reduced blood Ly-6C(high) monocytes levels and genetic reprogramming of lesional macrophages.