VASCULAR SURGERY Acute Care Vascular Surgery: Defining the Need for a Paradigm of Urgent and Emergent Vascular Surgery Donald G Harris, MD, Anthony V Herrera, Samantha R Cox, Michael E Huffner, Charles B Drucker, MD, Shahab Toursavadkohi, Jose J Diaz, Jr, MD, FACS, FCCM, Robert S Crawford, MD, FACS University of Maryland School of Medicine, Baltimore, MD INTRODUCTION: The paradigm of acute care surgery has revolu- tionized nonelective general surgery. Similarly, nonelective vascular surgery may benefit from specific management and resource capa- bilities. To establish the burden of acute vascular care, we analyzed the characteristics and outcomes of patients hospitalized for vascular surgical procedures in Maryland. METHODS: A retrospective analysis of a statewide inpatient data- base was performed to identify patients undergoing noncardiac vascular procedures in Maryland from 2009 to 2013. Patients were stratified by admission acuity as elective, urgent, or emergent, with the latter 2 groups defined as acute. The primary outcome was inpatient mortality, and secondary outcomes were critical care and hospital resource requirements. Groups were compared by univar- iate analyses, with multivariable analysis of mortality based on acu- ity level and other potential risk factors for death. RESULTS: Of 3,157,499 adult hospital admissions, 154,004 (5%) were for a vascular procedure; most were acute (54% emergent, 13% urgent), while 33% were elective (Table). Acute patients were more likely to be nongeriatric and nonwhite, and have renal or heart failure. Increasing acuity level was associated with higher rates of respiratory or renal failure, greater cost, longer hospitaliza- tion, and increased mortality. Admission for emergency vascular surgery was independently associated with mortality (odds ratio 3.0, 2.7 e 3.2). Table. Variable Elective (n¼50,488) Urgent, (n¼20,426) Emergent, (n¼83,090) p Value Demographic Age > 65 y, % 56 48 47 <.01 Nonwhite race, % 30 39 40 <.01 Comorbidity Chronic kidney disease, % 18 25 30 <.01 Heart failure, % 11 17 18 <.01 Secondary outcome Mechanical ventilation, % 4 6 10 <.01 Dialysis, % 6 10 12 <.01 Hospital charges, median $ 14,117 17,016 20,455 <.01 Hospital length of stay, d 2 3 5 <.01 Primary outcome Mortality 1 3 5 <.01 CONCLUSIONS: The majority of inpatient vascular care in Mary- land is for emergency vascular surgery, which is an independent risk factor for mortality. Acute vascular surgical care entails greater crit- ical care and hospital resource use, and, similar to emergency gen- eral surgery, may benefit from dedicated training and practice models. Blockade of Canonical Notch Signaling in Macrophages Alters the Inflammatory Response and Compounds Delayed Wound Healing in a Murine Model of Diabetes Andrew Kimball, MD, Amrita Joshi, PhD, Shreyas Ramani, Matthew Schaller, PhD, Jooho Chung, Peter Henke, MD, FACS, Steven Kunkel, PhD, Katherine Gallagher, MD, FACS University of Michigan, Ann Arbor, MI INTRODUCTION: Macrophages are critical immune cells for establishing a proper inflammatory response in wound healing. Although the role of Notch signaling in macrophages and inflam- mation has been loosely studied, the influence of Notch on macro- phage function has not been characterized in the setting of wound healing or diabetes. We sought to assess the effect of Notch signaling on inflammatory gene expression in a diet induced obese (DIO) model of diabetic wound healing. METHODS: We created a Lyz2-Cre mouse strain with a floxed Dominant Negative Mastermind-Like (DNMAML) gene in order to block downstream Notch signaling in myeloid cells. DNMAML f/f Cre+ and Cre- mice were placed on a normal diet or a standard high fat diet to induce the DIO model. Hind wounds were created, and wound healing was monitored using NIH ImageJ software. Macrophage inflammatory gene expression was assessed by quanti- tative reverse transcription polymerase chain reaction. RESULTS: DIO DNMAML f/f Cre+ mice demonstrated signifi- cantly delayed wound healing as compared with all other controls. Decreased inflammatory gene expression is seen in DNMAML f/f Cre+ bone marrow-derived macrophages (BMDM) when stimu- lated with LPS; however, this expression is not suppressed in DIO DNMAML f/f Cre+ mice. Further, when DIO BMDM are treated with a chemical Notch inhibitor, inflammatory gene expres- sion is not suppressed. CONCLUSIONS: Diabetic macrophages demonstrate preserved inflammatory gene expression in the setting of Notch inhibition when compared with normal diet controls. Altered Notch Signaling may contribute to impaired wound healing in diabetes. Further studies are needed to evaluate how DIO alters Notch signaling. eNOS Mediates Arteriovenous Fistula Maturation Jeans M Santana, Takuya Hashimoto, MD, PhD, Trenton R Foster, MD, Haidi Hu, MD, Hualong Bai, MD, Jesse J Hanisch, MD, PhD, Alan Dardik, MD, PhD, FACS Yale University, New Haven, CT INTRODUCTION: Arteriovenous fistulae (AVF) are the gold stan- dard for dialysis access, but low maturation rates limit their optimal use. We have previously shown that eNOS is a mediator of Eph- B4-regulated vein graft adaptation to the arterial environment. We hypothesized that eNOS is a mediator of AVF maturation. METHODS: The infrarenal aorto-caval AVF model was created in wild type (WT) C57BL/6 and eNOS knockout (KO) mice, with sham-operated mice as controls. Fistula maturation was monitored S163 http://dx.doi.org/10.1016/j.jamcollsurg.2016.06.017 ISSN 1072-7515/16