Circulating fibrillin fragment concentrations in patients with and without aortic pathology.

Objective: Fragments of fibrillin-1 and fibrillin-2 will be detectable in the plasma of patients with aortic dissections and aneurysms. We sought to determine whether the plasma fibrillin fragment levels (PFFLs) differ between patients with thoracic aortic pathology and those presenting with nonaortic chest pain. Methods: PFFLs were measured in patients with thoracic aortic aneurysm (n = 27) or dissection (n = 28). For comparison, patients without aortic pathology who had presented to the emergency department with acute chest pain (n = 281) were categorized into three groups according to the cause of the chest pain: ischemic cardiac chest pain; nonischemic cardiac chest pain; and noncardiac chest pain. The PFFLs were measured using a sandwich enzyme-linked immunosorbent assay. Results: Fibrillin-1 fragments were detectable in all patients and were lowest in the ischemic cardiac chest pain group. Age, sex, and the presence of hypertension were associated with differences in fibrillin-1 fragment levels. Fibrillin-2 fragments were detected more often in the thoracic aneurysm and dissection groups than in the emergency department chest pain group (P < .0001). Patients with aortic dissection demonstrated a trend toward increased detectability (P = .051) and concentrations (P = .06) of fibrillin-2 fragments compared with patients with aortic aneurysms. Analysis of specific antibody pairs identified fibrillin-1 B15-HRP26 and fibrillin-2 B205-HRP143 as the most informative in distinguishing between the emergency department and aortic pathology groups. Conclusions: Patients with thoracic aortic dissections demonstrated elevated plasma fibrillin-2 fragment levels (B205-HRP143) compared with patients presenting with ischemic or nonischemic cardiac chest pain and increased fibrillin-1 levels (B15-HRP26) compared with patients with ischemic cardiac chest pain. Investigation of fibrillin-1 and fibrillin-2 fragment generation might lead to diagnostic, therapeutic, and prognostic advances for patients with thoracic aortic dissection.

A Novel Model of Tobacco Smoke-Mediated Aortic Injury.

OBJECTIVE: Tobacco smoke exposure is a major risk factor for aortic aneurysm development. However, the initial aortic response to tobacco smoke, preceding aneurysm formation, is not well understood. We sought to create a model to determine the effect of solubilized tobacco smoke (STS) on the thoracic and abdominal aorta of mice as well as on cultured human aortic smooth muscle cells (HASMCs). METHODS: Tobacco smoke was solubilized and delivered to mice via implanted osmotic minipumps. Twenty male C57BL/6 mice received STS or vehicle infusion. The descending thoracic, suprarenal abdominal, and infrarenal abdominal segments of the aorta were assessed for elastic lamellar damage, smooth muscle cell phenotype, and infiltration of inflammatory cells. Cultured HASMCs grown in media containing STS were compared to cells grown in standard media in order to verify our in vivo findings. RESULTS: Tobacco smoke solution caused significantly more breaks in the elastic lamellae of the thoracic and abdominal aorta compared to control solution (P< .0001) without inciting an inflammatory infiltrate. Elastin breaks occurred more frequently in the abdominal aorta than the thoracic aorta (P < .01). Exposure to STS-induced aortic microdissections and downregulation of α-smooth muscle actin (α-SMA) by vascular smooth muscle cells (VSMCs). Treatment of cultured HASMCs with STS confirmed the decrease in α-SMA expression. CONCLUSION: Delivery of STS via osmotic minipumps appears to be a promising model for investigating the early aortic response to tobacco smoke exposure. The initial effect of tobacco smoke exposure on the aorta is elastic lamellar damage and downregulation of (α-SMA) expression by VSMCs. Elastic lamellar damage occurs more frequently in the abdominal aorta than the thoracic aorta and does not seem to be mediated by the presence of macrophages or other inflammatory cells.

Predictors of Abdominal Aortic Aneurysm Risks.

Computational biomechanics via finite element analysis (FEA) has long promised a means of assessing patient-specific abdominal aortic aneurysm (AAA) rupture risk with greater efficacy than current clinically used size-based criteria. The pursuit stems from the notion that AAA rupture occurs when wall stress exceeds wall strength. Quantification of peak (maximum) wall stress (PWS) has been at the cornerstone of this research, with numerous studies having demonstrated that PWS better differentiates ruptured AAAs from non-ruptured AAAs. In contrast to wall stress models, which have become progressively more sophisticated, there has been relatively little progress in estimating patient-specific wall strength. This is because wall strength cannot be inferred non-invasively, and measurements from excised patient tissues show a large spectrum of wall strength values. In this review, we highlight studies that investigated the relationship between biomechanics and AAA rupture risk. We conclude that combining wall stress and wall strength approximations should provide better estimations of AAA rupture risk. However, before personalized biomechanical AAA risk assessment can become a reality, better methods for estimating patient-specific wall properties or surrogate markers of aortic wall degradation are needed. Artificial intelligence methods can be key in stratifying patients, leading to personalized AAA risk assessment.

Causes and outcomes of finger ischemia in hospitalized patients in the intensive care unit.

OBJECTIVE: Vascular surgeons may be consulted to evaluate hospitalized patients with finger ischemia. We sought to characterize causes and outcomes of finger ischemia in intensive care unit (ICU) patients. METHODS: All ICU patients who underwent evaluation for finger ischemia from 2008 to 2015 were reviewed. All were evaluated with finger photoplethysmography. The patients' demographics, comorbidities, ICU care (ventilator status, arterial lines, use of vasoactive medications), finger amputations, and survival were also recorded. ICU patients were compared with concurrently evaluated non-ICU inpatients with finger ischemia. RESULTS: There were 98 ICU patients (55 male, 43 female) identified. The mean age was 57.1 ± 16.8 years. Of these patients, 42 (43%) were in the surgical ICU and 56 (57%) in the medical ICU. Seventy (72%) had abnormal findings on finger photoplethysmography, 40 (69%) unilateral and 30 (31%) bilateral. Thirty-six (37%) had ischemia associated with an arterial line. Twelve (13%) had concomitant toe ischemia. Eighty (82%) were receiving vasoactive medications at the time of diagnosis, with the most frequent being phenylephrine (55%), norepinephrine (47%), ephedrine (31%), epinephrine (26%), and vasopressin (24%). Treatment was with anticoagulation in 88 (90%; therapeutic, 48%; prophylactic, 42%) and antiplatelet agents in 59 (60%; aspirin, 51%; clopidogrel, 15%). Other frequently associated conditions included mechanical ventilation at time of diagnosis (37%), diabetes (34%), peripheral arterial disease (32%), dialysis dependence (31%), cancer (24%), and sepsis (20%). Only five patients (5%) ultimately required finger amputation. The 30-day, 1-year, and 3-year survival was 84%, 69%, and 59%. By Cox proportional hazards modeling, cancer (hazard ratio, 2.4; 95% confidence interval, 1.1-5.6; P = .035) was an independent predictor of mortality. There were 50 concurrent non-ICU patients with finger ischemia. Non-ICU patients were more likely to have connective tissue disorders (26% vs 13%; P = .05) and hyperlipidemia (42% vs 24%; P = .03) and to undergo finger amputations (16% vs 5%; P = .03). CONCLUSIONS: Finger ischemia in the ICU is frequently associated with the presence of arterial lines and the use of vasopressor medications, of which phenylephrine and norepinephrine are most frequent. Anticoagulation or antiplatelet therapy is appropriate treatment. Whereas progression to amputation is rare, patients with finger ischemia in the ICU have a high rate of mortality, particularly in the presence of cancer. Non-ICU patients hospitalized with finger ischemia more frequently require finger amputations, probably because of more frequent connective tissue disorders.

Characterization of profunda femoris vein thrombosis.

OBJECTIVE: The incidence of and risk factors for profunda femoris vein (PFV) thrombosis are poorly characterized. We prospectively identified patients with PFV deep venous thrombosis (DVT) to characterize the demographics and anatomic distribution of proximal DVT in patients with PFV DVT. METHODS: A prospective study was conducted of patients at a tertiary care university hospital with DVT diagnosed by venous duplex ultrasound scanning between June 2014 and June 2015. DVT patients were categorized as having PFV involvement (yes or no), and the anatomic distribution of other sites of ipsilateral venous thrombi was further stratified to determine whether there was external iliac vein (EIV), common femoral vein (CFV), or femoropopliteal vein (FPV) DVT. Demographic characteristics of the patients were compared between groups, PFV DVT vs proximal DVT without PFV DVT. RESULTS: Of 4584 lower extremity venous duplex ultrasound studies performed, 398 (8.7%) scans were positive for proximal DVT from 260 patients; 23.1% of patients with DVT (60/260) had DVT involving the PFV. Of 112 patients who had CFV DVT, 55 (49.1%) also had ipsilateral involvement of the PFV. Of 60 patients with PFV DVT, 55 (91.7%) had involvement of the ipsilateral CFV. Patients in the PFV DVT group were more likely to have a history of a hypercoagulable disorder (26.7% vs 14.5%; P = .029) and a history of immobility (58.3% vs 42%; P = .026) compared with those with proximal DVT without PFV DVT. There were no differences in smoking, recent surgery, personal or family history of DVT, other medical comorbidities, inpatient status, or survival. There was no difference in laterality of DVT between the PFV DVT and proximal DVT without PFV DVT groups (35% vs 41.5% left, 35% vs 33.5% right, 30% vs 25% bilateral; P = .619). There was a higher proportion of PFV DVT with EIV involvement (21.7% vs 2.5%; P < .00001) and a higher proportion of PFV DVT with CFV + FPV involvement (65.0% vs 19%; P < .00001) compared with proximal DVT without PFV DVT. There was no difference in survival between the PFV DVT and proximal DVT without PFV DVT groups. CONCLUSIONS: Patients with PFV thrombosis tend to have more thrombus burden with more frequent concurrent DVT in the EIV and FPV. Patients with PFV DVT are also more likely to have a history of hypercoagulable disorder and immobility. Ultrasound protocols for assessment of DVT should include routine examination of the PFV as a potential marker of a more virulent prothrombotic state.

Tibial artery duplex ultrasound-derived peak systolic velocities may be an objective performance measure after above-knee endovascular therapy for arterial stenosis.

OBJECTIVE: The ankle-brachial index (ABI) is a well-established measure of distal perfusion in lower extremity ischemia; however, the ABI is of limited value in patients with noncompressible lower extremity arteries. We sought to demonstrate whether duplex ultrasound-determined tibial artery velocities can be used as an alternative to ABI as an objective performance measure after endovascular treatment of above-knee arterial stenosis. METHODS: Thirty-six patients undergoing above-knee endovascular intervention had preprocedure and postprocedure duplex ultrasound examination within 6 months of intervention. Preprocedure vs postprocedure changes in tibial artery mean peak systolic velocity (PSV; mean of proximal, mid, and distal velocities) were compared with changes in ABI and a reference (control) cohort of 68 patients without peripheral vascular disease. RESULTS: Thirty-six patients (41 limbs) had an above-knee endovascular intervention and had preprocedure and postprocedure duplex ultrasound examinations of the ipsilateral extremity including the tibial arteries. Before the procedure, mean tibial artery PSVs in the 36 patients undergoing intervention were outside (below) the 95% confidence intervals for the control patients. In comparing preprocedure and postprocedure PSVs, the mean anterior tibial (P < .01), mean peroneal (P < .01), and mean posterior tibial (P < .01) PSVs all increased and correlated with an increase in ABI (P < .01). After endovascular intervention, duplex ultrasound-derived mean PSVs fell within or near established reference ranges for patients without peripheral arterial disease. Mean tibial artery PSV increases were similar in patients with and without noncompressible vessels. CONCLUSIONS: Tibial artery PSVs increase, correlate with an increase in ABI, and fall within or near confidence intervals for normal controls after above-knee endovascular interventions. After endovascular intervention, tibial artery PSVs can supplement ABI as an objective performance measure in patients with and in particular without compressible tibial arteries.

Ambulation and functional outcome after major lower extremity amputation.

OBJECTIVE: Major lower extremity amputations (MLEAs) remain a significant source of disability. It is unknown whether postamputation functional outcomes and outcome predictability have changed with a population of increasingly aging and obese patients. Accordingly, we sought to evaluate contemporary trends. METHODS: A retrospective chart review was performed to identify patients undergoing MLEA using Current Procedural Terminology codes in a university hospital. Demographics, comorbidities, perioperative variables, and outcomes were obtained. Descriptive statistics, t-tests, and χ2 and multivariate logistic regression modeling were used where appropriate. Survival analyses were performed with the Kaplan-Meier method. RESULTS: From October 2005 to November 2016, 206 patients (147 male; mean age, 63 ± 13.5 years) underwent 256 MLEAs (90.9% below-knee amputations, 1.3% through-knee amputations, and 7.8% above-knee amputations [AKAs]) related to acute and critical limb ischemia, infection, or other causes. Mean follow-up was 178.7 ± 266.9 days. Conversion from below-knee amputation to AKA was 3.5%. Estimated 1-year survival was 83%, and it was 15% lower in nonambulatory patients (75% vs 90%; P = .04). Overall 1-year postamputation ambulatory rate was 46.1%. Nonambulatory patients had a higher body mass index (30.9 ± 8.0 vs 25.6 ± 5.4; P < .001), lower preoperative hematocrit (31.0% ± 7.4% vs 33.3% ± 8.1%; P < .05), higher modified frailty index (mFI; 8.4 ± 1.0 vs 5.4 ± 1.2; P < .0001), higher chronic alcohol use (9% vs 1%; P = .01), dependent preoperative functional status (29% vs 2.1%; P < .01), and lack of family support (66.3% vs 17.9%; P < .01); they were less likely to be married (83.2% vs 35.8%; P < .01) and more likely to have an AKA (20% vs 52.6%; P = .004). There were no patients with dementia, on dialysis, or with bilateral MLEAs who were ambulatory after amputation. Factors predictive of nonambulatory status after MLEA with multivariate logistic regression analysis included increased body mass index (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.81-0.98; P = .017) and an increased mFI (OR, 0.23; 95% CI, 0.16-0.34; P < .0001); a higher hemoglobin level was protective (OR, 1.3; 95% CI, 1.03-1.62; P = .019). CONCLUSIONS: Patients should be counseled that <50% of patients receiving MLEAs are ambulatory after amputation. Educating patients about the deleterious effects of obesity on ambulatory status after MLEA may motivate patients to improve their level of fitness to achieve successful ambulation. Patients with an elevated mFI, patients with dementia, and those on dialysis should be considered for AKAs.

Nonatherosclerotic vascular causes of acute abdominal pain.

BACKGROUND: To examine the epidemiology, treatments, and outcomes of acute symptomatic non-atherosclerotic mesenteric vascular disease. METHODS: Subjects were reviewed over a six year period. Categories included embolism (EM), dissection (DI), and aneurysm (AN). Presentation, demographics, treatment and outcomes were compared. RESULTS: 46 patients were identified (EM:20, AN:15, DI:11). Age at presentation differed (EM: 66.3, AN 62.4, DI 54.6, p < .05). EM more likely affected the superior mesenteric artery (EM80%, AN20%, DI45%, p = .002), DI hepatic artery (EM20%, AN13%, DI55%, p < .05), and AN mesenteric branches (EM5%, AN47%, DI0%; p = .001). EM more likely had history of arrhythmia (EM40%, AN7%, DI0%, p,0.05) and diarrhea (EM30%, AN7%, DI0%, p < .05). Treatment was most often surgical in EM (EM85%, AN33%, DI9%, p < .001), endovascular in AN (EM5%, AN40%, DI 9%, p < .02), and conservative in DI (EM15%, AN 33%, DI82%, p < .05). In hospital mortality was infrequent (EM10%, AN7%, DI0%, p = ns). Mean hospital length of stay differed by mechanism (EM13.6days, AN9.2, DI2.3, p = .005). Median follow up was 61 months. Survival at 1, 3 and 5 years for emboli was 75%, 70% and 59%, for aneurysms 93%, 86%, and 77%, and for dissections 100% at all time points (p = .043 log rank). CONCLUSIONS: Patients with EM, AN, and DI differ in age, anatomic distribution and method of treatment. The etiology significantly affects long term survival.

Intraluminal thrombus is associated with early rupture of abdominal aortic aneurysm.

BACKGROUND: The implications of intraluminal thrombus (ILT) in abdominal aortic aneurysm (AAA) are currently unclear. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing wall stress, whereas other studies have associated ILT with aortic wall weakening. It is further unclear why some aneurysms rupture at much smaller diameters than others. In this study, we sought to explore the association between ILT and risk of AAA rupture, particularly in small aneurysms. METHODS: Patients were retrospectively identified and categorized by maximum aneurysm diameter and rupture status: small (<60 mm) or large (≥60 mm) and ruptured (rAAA) or nonruptured (non-rAAA). Three-dimensional AAA anatomy was digitally reconstructed from computed tomography angiograms for each patient. Finite element analysis was then performed to calculate peak wall stress (PWS) and mean wall stress (MWS) using the patient's systolic blood pressure. AAA geometric properties, including normalized ILT thickness (mean ILT thickness/maximum diameter) and % volume (100 × ILT volume/total AAA volume), were also quantified. RESULTS: Patients with small rAAAs had PWS of 123 ± 51 kPa, which was significantly lower than that of patients with large rAAAs (242 ± 130 kPa; P = .04), small non-rAAAs (204 ± 60 kPa; P < .01), and large non-rAAAs (270 ± 106 kPa; P < .01). Patients with small rAAAs also had lower MWS (44 ± 14 kPa vs 82 ± 20 kPa; P < .02) compared with patients with large non-rAAAs. ILT % volume and normalized ILT thickness were greater in small rAAAs (68% ± 11%; 0.16 ± 0.04 mm) compared with small non-rAAAs (53% ± 16% [P = .02]; 0.11 ± 0.04 mm [P < .01]) and large non-rAAAs (57% ± 12% [P = .02]; 0.12 ± 0.03 mm [P < .01]). Increased ILT % volume was associated with both decreased MWS and decreased PWS. CONCLUSIONS: This study found that although increased ILT is associated with lower MWS and PWS, it is also associated with aneurysm rupture at smaller diameters and lower stress. Therefore, the protective biomechanical advantage that ILT provides by lowering wall stress seems to be outweighed by weakening of the AAA wall, particularly in patients with small rAAAs. This study suggests that high ILT burden may be a surrogate marker of decreased aortic wall strength and a characteristic of high-risk small aneurysms.

Effect of systemic insulin treatment on diabetic wound healing.

This study investigates if different diabetic treatment regimens affect diabetic foot ulcer healing. From January 2013 to December 2014, 107 diabetic foot ulcers in 85 patients were followed until wound healing, amputation or development of a nonhealing ulcer at the last follow-up visit. Demographic data, diabetic treatment regimens, presence of peripheral vascular disease, wound characteristics, and outcome were collected. Nonhealing wound was defined as major or minor amputation or those who did not have complete healing until the last observation. Median age was 60.0 years (range: 31.1-90.1 years) and 58 cases (68.2%) were males. Twenty-four cases reached a complete healing (healing rate: 22.4%). The median follow-up period in subjects with classified as having chronic wounds was 6.0 months (range: 0.7-21.8 months). Insulin treatment was a part of diabetes management in 52 (61.2%) cases. Insulin therapy significantly increased the wound healing rate (30.3% [20/66 ulcers] vs. 9.8% [4/41 ulcers]) (p = 0.013). In multivariate random-effect logistic regression model, adjusting for age, gender, smoking status, type of diabetes, hypertension, chronic kidney disease, peripheral arterial disease, oral hypoglycemic use, wound infection, involved side, presence of Charcot's deformity, gangrene, osteomyelitis on x-ray, and serum hemoglobin A1C levels, insulin treatment was associated with a higher chance of complete healing (beta ± SE: 15.2 ± 6.1, p = 0.013). Systemic insulin treatment can improve wound healing in diabetic ulcers after adjusting for multiple confounding covariates.

Predictive value of neutrophil-to-lymphocyte ratio in diabetic wound healing.

OBJECTIVE: The neutrophil-to-lymphocyte ratio (NLR) has been used as a surrogate marker of systemic inflammation. We sought to investigate the association between NLR and wound healing in diabetic wounds. METHODS: The outcomes of 120 diabetic foot ulcers in 101 patients referred from August 2011 to December 2014 were examined retrospectively. Demographic, patient-specific, and wound-specific variables as well as NLR at baseline visit were assessed. Outcomes were classified as ulcer healing, minor amputation, major amputation, and chronic ulcer. RESULTS: The subjects' mean age was 59.4 ± 13.0 years, and 67 (66%) were male. Final outcome was complete healing in 24 ulcers (20%), minor amputation in 58 (48%) and major amputation in 16 (13%), and 22 chronic ulcers (18%) at the last follow-up (median follow-up time, 6.8 months). In multivariate analysis, higher NLR (odds ratio, 13.61; P = .01) was associated with higher odds of nonhealing. CONCLUSIONS: NLR can predict odds of complete healing in diabetic foot ulcers independent of wound infection and other factors.

Patterns of Care in Hospitalized Vascular Surgery Patients at End of Life.

Importance: There is limited literature reporting circumstances surrounding end-of-life care in vascular surgery patients. Objective: To identify factors driving end-of-life decisions in vascular surgery patients. Design, Setting, and Participants: In this cohort study, medical records were reviewed for all vascular surgery patients at a tertiary care university hospital who died during their hospitalization from 2005 to 2014. Main Outcomes and Measures: Patient, family, and hospitalization variables potentially important to influencing end-of-life decisions. Results: Of 111 patients included (67 [60%] male; median age, 75 [range, 24-94] years), 81 (73%) were emergent vs 30 (27%) elective admissions. Only 15 (14%) had an advance directive. Of the 81 (73%) patients placed on comfort care, 31 (38%) had care withheld or withdrawn despite available medical options, 15 (19%) had an advance directive, and 28 (25%) had a palliative care consultation. The median time from palliative care consultation to death was 10 hours (interquartile range, 3.36-66 hours). Comparing the 31 patients placed on comfort care despite available medical options with an admission diagnosis-matched cohort, we found that more than 5 days admitted to the intensive care unit (odds ratio [OR], 4.11; 95% CI, 1.59-10.68; P < .001), more than 5 days requiring ventilator support (OR, 9.45; 95% CI, 3.41-26.18; P < .001), new renal failure necessitating dialysis (OR, 14.48; 95% CI, 3.69-56.86; P < .001), and new respiratory failure necessitating tracheostomy (OR, 23.92; 95% CI, 2.80-204; P < .001) correlated with transition to comfort care. Conclusions and Relevance: Palliative care consultations may be underused at the end of life. A large percentage of patients were transitioned to comfort measures despite available treatment, yet few presented with advance directives. In high-risk patients, discussions regarding extended stays in the intensive care unit, prolonged ventilator management, and possible dialysis and tracheostomy should be communicated with patients and families at time of hospitalization and advance directives solicited.

Demographic and echocardiographic predictors of anatomic site and outcomes of surgical interventions for cardiogenic limb emboli.

We sought to determine if symptomatic cardiogenic limb emboli have a random distribution or if there are demographic or echocardiographic factors that predict site of embolization, limb salvage and mortality. Upper (UE) and lower extremity (LE) emboli were evaluated over a 16-year period (1996-2012). Demographic (age, gender, smoking, medical comorbidities) and echocardiographic data were analyzed to determine predictors of embolic site. All symptomatic patients underwent surgical revascularization. Limb salvage and mortality were compared with Kaplan-Meier analysis. A total of 161 patients with symptomatic cardiogenic emboli were identified: 56 UE and 105 LE. The female-to-male ratio for UE emboli (70%:30%) was significantly higher than for LE emboli (47%:53%, p=0.008). No other demographic factors were statistically different. Upper extremity patients were more likely to have atrial fibrillation (50% vs 29.8%, p=0.028), while LE patients had a higher percentage of aortic or mitral valvular disease or intracardiac thrombus (71.4% vs 52.5%, p=0.038). The 30-day limb salvage was higher for UE compared to LE (100% vs 88%, p=0.008). There was a trend toward higher 30-day mortality in the LE group (14% vs 5%, p=0.11). Survival at 1, 3, and 5 years were similar (UE: 62.2%, 44.2%, 35.3%; LE: 69.1%, 47.5%, 30.3%; p=ns). Upper extremity emboli are more frequent in women and patients with atrial fibrillation. Lower extremity emboli are more frequent in the presence of valvular disease or intracardiac thrombus, and are associated with increased 30-day limb loss and mortality. These findings suggest gender- and cardiac-specific differences in patterns of blood flow leading to preferential sites of peripheral embolization.

Aortic outflow occlusion predicts rupture of abdominal aortic aneurysm.

BACKGROUND: Current threshold recommendations for elective abdominal aortic aneurysm (AAA) repair are based solely on maximal AAA diameter. Peak wall stress (PWS) has been demonstrated to be a better predictor than AAA diameter of AAA rupture risk. However, PWS calculations are time-intensive, not widely available, and therefore not yet clinically practical. In addition, PWS analysis does not account for variations in wall strength between patients. We therefore sought to identify surrogate clinical markers of increased PWS and decreased aortic wall strength to better predict AAA rupture risk. METHODS: Patients treated at our institution from 2001 to 2014 for ruptured AAA (rAAA) were retrospectively identified and grouped into patients with small rAAA (maximum diameter <6 cm) or large rAAA (>6 cm). Patients with large (>6 cm) non-rAAA were also identified sequentially from 2009 for comparison. Demographics, vascular risk factors, maximal aortic diameter, and aortic outflow occlusion (AOO) were recorded. AOO was defined as complete occlusion of the common, internal, or external iliac artery. Computational fluid dynamics and finite element analysis simulations were performed to calculate wall stress distributions and to extract PWS. RESULTS: We identified 61 patients with rAAA, of which 15 ruptured with AAA diameter <60 mm (small rAAA group). Patients with small rAAAs were more likely to have peripheral arterial disease (PAD) and chronic obstructive pulmonary disease (COPD) than were patients in the large non-rAAA group. Patients with small rAAAs were also more likely to have AOO compared with non-rAAAs >60 mm (27% vs 8%; P = .047). Among all patients with rAAAs, those with AOO ruptured at smaller mean AAA diameters than in patients without AOO (62.1 ± 11.8 mm vs 72.5 ± 16.4 mm; P = .024). PWS calculations of a representative small rAAA and a large non-rAAA showed a substantial increase in PWS with AOO. CONCLUSIONS: We demonstrate that AOO, PAD, and COPD in AAA are associated with rAAAs at smaller diameters. AOO appears to increase PWS, whereas COPD and PAD may be surrogate markers of decreased aortic wall strength. We therefore recommend consideration of early, elective AAA repair in patients with AOO, PAD, or COPD to minimize risk of early rupture.

The role of axillofemoral bypass in current vascular surgery practice.

BACKGROUND: In the era of increasing endovascular approaches for aortoiliac disease, we sought to determine the role of axillofemoral bypass in contemporary practice. METHODS: All axillofemoral bypasses performed at our institution from 2006 to 2013 were reviewed for indication, patency, and survival and compared with our prior published series before the widespread use of endovascular techniques (1996 to 2001). RESULTS: During the study period, 90 bypasses (29 axillofemoral and 61 axillobifemoral) bypasses were performed. The number of procedures performed decreased from an average of 24 to 12 procedures per year in historical and contemporary groups, respectively. Indications have changed significantly with more urgent or emergent procedures. Overall patency at 1 and 2 years was 74.6% and 67.8%, respectively. Median survival was 40.3 months, with overall survival 67.0% and 54.2% at 1 and 2 years, respectively. CONCLUSIONS: Axillofemoral bypass is an increasingly uncommon procedure and more likely performed for limb salvage in urgent or emergent settings.

The Natural History of Indeterminate Blunt Cerebrovascular Injury.

IMPORTANCE: The Denver criteria grade blunt cerebrovascular injuries (BCVIs) but fail to capture many patients with indeterminate findings on initial imaging. OBJECTIVE: To evaluate outcomes and clinical significance of indeterminate BCVIs (iBCVIs). DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of all patients treated for BCVIs at our institution from January 1, 2007, through July 31, 2014, was completed. Patients were divided into 2 groups: those with true BCVIs as defined by the Denver criteria and those with iBCVIs, which was any initial imaging suggestive of a cerebrovascular arterial injury not classifiable by the Denver criteria. MAIN OUTCOMES AND MEASURES: Primary outcomes were rate of resolution of iBCVIs, freedom from cerebrovascular accident (CVA) or transient ischemic attack (TIA), and 30-day mortality. RESULTS: We identified 100 patients with 138 BCVIs: 79 with true BCVIs and 59 with iBCVIs. With serial imaging, 23 iBCVIs (39.0%) resolved and 21 (35.6%) remained indeterminate, whereas 15 (25.4%) progressed to true BCVI. The rate of CVA or TIA in the iBCVI group was 5.1% compared with 15.2% in the true BCVI group (P = .06). Of the 15 total CVAs or TIAs, 11 (73.3%) resulted from carotid injury and 4 (26.7%) from vertebral artery occlusion (P = .03). By Kaplan-Meier analysis, there was no difference in freedom from CVA or TIA for the 2 groups (P = .07). Median clinical follow-up was 91 days. Overall and 30-day mortality for the entire series were 17.4% and 15.2%, respectively. There was no difference in long-term or 30-day mortality between true BCVI and iBCVI groups. CONCLUSIONS AND RELEVANCE: Detection of iBCVI has become a common clinical conundrum with improved and routine imaging. Indeterminate BCVI is not completely benign, with 25.4% demonstrating anatomical progression to true BCVI and 5.1% developing cerebrovascular symptoms. We therefore recommend serial imaging and antiplatelet therapy for iBCVI.

Incidence and outcomes of intraoperative vascular surgery consultations.

OBJECTIVE: Vascular surgeons may aid in primarily nonvascular procedures. Such activity has not been quantified, and hospital administrators may be unaware of the importance of vascular surgeons to support other hospital-based surgical programs. This study reviewed intraoperative consultations by vascular surgeons to support other surgical services. METHODS: Intraoperative vascular consultations were reviewed from January 2006 to January 2014 for consulting service, indication, and whether consultation occurred with advanced notice. Patient demographics, operative times, estimated blood loss, length of stay, and relative value units (RVUs) assigned for each consultation were also assessed. Consultations for trauma and iatrogenic injuries occurring outside the operating theater were excluded. RESULTS: Vascular surgeons performed 225 intraoperative consultations in support of procedures by nonvascular surgeons. Requesting services were surgical oncology (46%), orthopedics (17%), urology (11%), otolaryngology (7%), and others (19%). Reasons for consultation overlapped and included vascular reconstruction (53%), control of hemorrhage (39%), and assistance with difficult dissections (43%). Seventy-four percent were for intra-abdominal procedures, and venous (53%) and arterial (50%) problems were encountered equally with some overlap. Most patients were male (59%), overweight (56%; body mass index ≥25 kg/m(2)), had previous surgery (72%) and were undergoing elective procedures (89%). Mean total procedural anesthesia time was 9.4 hours, mean procedural operating time was 7.9 hours, and mean total and vascular-related estimated blood loss was 1702 mL and 327 mL, respectively. Mean length of stay was 14.7 days, mean intensive care unit stay was 2.9 days, and 30-day mortality was 6.2%. Mean nonvascular RVUs per operation were 46.0, and mean vascular RVUs per operation were 30.9. CONCLUSIONS: Unexpected intraoperative need for vascular surgical expertise occurs often enough that vascular surgeons should be regarded as an essential operating room resource to the general operating room, nonvascular surgeons, and their patients. Intraoperative vascular surgical consultation in support of other surgeons requires a high level of open technical operative skills and is time and labor intensive.

Nasal methicillin-resistant Staphylococcus aureus colonization is associated with increased wound occurrence after major lower extremity amputation.

OBJECTIVE: Wound occurrence (WO) after major lower extremity amputation (MLEA) can be due to wound infection or sterile dehiscence. We sought to determine the association of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and other patient factors with overall WO, WO due to wound infection, and WO due to sterile dehiscence. METHODS: The medical records of all patients undergoing MLEA from August 1, 2011, to November 1, 2013, were reviewed. Demographic data, hemoglobin A1c level, albumin concentration, dialysis dependence, peripheral vascular disease (PVD), nasal MRSA colonization, and diabetes mellitus (DM) were examined as variables. The overall WO rate was determined, and the cause of WO was categorized as either a sterile dehiscence or a wound infection. RESULTS: Eighty-three patients underwent 96 MLEAs during a 27-month period. The rates of overall WO, WO due to infection, and WO due to sterile dehiscence were 39%, 19%, and 19%, respectively (1% developed a traumatic wound). On univariate analysis, PVD, MRSA colonization, DM, and dialysis dependence were all associated with higher rates of overall WO (P < .05). On multivariate analysis, MRSA colonization was associated with higher rates of overall WO (P = .03) and WO due to wound infection (11% vs 45%; P < .01). DM and PVD were associated with higher rates of overall WO and WO due to sterile dehiscence on both univariate and multivariate analysis (P < .05). CONCLUSIONS: Nasal MRSA colonization is associated with higher rates of overall WO and WO due to wound infection. DM and PVD are associated with higher rates of overall WO and WO due to sterile dehiscence but are not associated with WO due to wound infection. Further studies addressing the effect of nasal MRSA eradication on postoperative wound outcomes after MLEA are warranted.

Objective measurement of lower extremity function and quality of life after surgical revascularization for critical lower extremity ischemia.

BACKGROUND: Outcomes of revascularization for critical limb ischemia (CLI) have historically been patency, limb salvage, and survival. Functional status and quality of life have not been well described. This study used functional and quality of life assessments to measure patient-centered outcomes after revascularization for CLI. METHODS: The study observed 18 patients (age, 65 ± 11 years) prospectively before and after lower extremity bypass for CLI. Patients completed the Short Physical Performance Battery, which measures walking speed, leg strength, and balance, as well as performed a 6-minute walk, and calorie expenditure was measured by an accelerometer. Isometric muscle strength was assessed with the Muscle Function Evaluation chair (Metitur, Helsinki, Finland). Quality of life instruments included the 36-Item Short Form Health Survey and the Vascular Quality of Life questionnaire. Patients' preoperative status was compared with 4-month postoperative status. RESULTS: Muscle Function Evaluation chair measurements of ipsilateral leg strength demonstrated a significant increase in knee flexion from 64 ± 62 N to 135 ± 133 N (P = .038) and nearly significant increase in knee extension from 120 ± 110 N to 186 ± 85 N (P = .062) and ankle plantar flexion from 178 ± 126 N to 267 ± 252 N (P = .078). In the contralateral leg, knee flexion increased from 71 ± 96 N to 149 ± 162 N (P = .028) and knee extension from 162 ± 112 N to 239 ± 158 N (P = .036). Absolute improvements were noted in 6-minute walk distance, daily calorie expenditure, and individual domains and overall Short Physical Performance Battery scores, and upper extremity strength decreased, although none were significant. The Vascular Quality of Life questionnaire captured significant improvement in all individual domains and overall score (P < .015). Significant improvement was noted only for bodily pain (P = .011) on the 36-Item Short Form Health Survey. CONCLUSIONS: Despite lack of statistical improvement in most functional test results, revascularization for CLI results in improved patient-perceived leg function. Significant improvements in isometric muscle strength may explain the measured improvement in quality of life after revascularization for CLI.