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.

Duplex ultrasound and clinical outcomes of medical management of pediatric lower extremity arterial thrombosis.

OBJECTIVES: Natural history and duplex ultrasound (DU) findings of pediatric lower extremity arterial thrombosis (PLEAT) are not well-defined. We describe acute and short-term DU findings of PLEAT to aid duplex interpretation and patient management. METHODS: From August 2018 to April 2021 children with suspected PLEAT were identified prospectively. All had DU studies and were divided into group 1 (with DU-confirmed PLEAT) and group 2 (without DU-confirmed PLEAT). Patient demographics and DU findings were compared. Those with PLEAT and follow-up DU studies were also evaluated for recanalization and post recanalization DU findings. RESULTS: We included 76 children (102 limbs) who had suspected PLEAT; 32 in group 1 and 44 group in 2. Fifty-seven percent had congenital heart disease, 26% a history prematurity (87%, 34% group 1; 11%, 14% group 2), with 14% of group 1 premature at PLEAT diagnosis and 68% aged less than 3 years-29 (94%) in group 1 and 23 (52%) in group 2. None had an arterial procedure to restore flow. Limb salvage was 100% with five group 1 mortalities unrelated to PLEAT. In group 1, 12 PLEATs were associated with an arterial line and 15 with cardiac catheterization. Occluded arteries included 7 external iliac, 20 common femoral, and 5 superficial femoral arteries (SFA). Peak systolic velocities (PSVs) distal to occluded segments in group 1 were lower than corresponding group 2 PSVs. SFA 18 ± 21 cm/s vs 84 ± 39 cm/s; popliteal artery (PA) 24 ± 18 cm/s vs 78 ± 38 cm/s; posterior tibial artery (PTA) 10 ± 8 cm/s versus 49 ± 27 cm/s (all P < .001). Twenty-one patients in group 1 had follow-up studies. Twelve (57%) were recanalized: 4 (19%) in less than 1 week and 10 (48%) by 6 months. Eighty-one percent of PLEATs were treated with anticoagulation (AC) and 57% recanalized. Fifty-nine percent of patients on AC recanalized, and 60% not on AC recanalized. Age, primary diagnosis, instrumentation type, and AC were not associated with failure to recanalize. After recanalization, PSVs in the CFA were not different than PSVs found in group 2 in the CFA (109 ± 50 cm/s vs 107 ± 57 cm/s; P = .88), but remained decreased in the SFA, PA, and PTA (SFA 68 ± 32 cm/s vs 83 ± 38 cm/s [P = .04]; PA 33 ± 13 cm/s vs 78 ± 37 [P = .0004]; and PTA 21 ± 8 cm/s vs 43 ± 20 cm/s [P = .0008]). CONCLUSIONS: PLEAT occurs in young children, results in low distal PSVs, and often does not recanalize, but does not lead to short-term limb loss or mortality or necessarily require AC for recanalization. Normalization of CFA PSVs indicates recanalization while PSVs in segments distal to the CFA do not seem to return to normal.

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.

Ultrasound therapy for treatment of lower extremity intermittent claudication.

BACKGROUND: While often thought of as a diagnostic tool, ultrasound (US) can also potentially be used as a therapeutic modality. US applies mechanical stress on endothelial cells and induces nitric oxide synthase, which regulates the secretion of nitric oxide, a potent vasodilator. In animal ischemic models, US has been shown to improve hindlimb, myocardial, and cerebral perfusion. We performed a pilot trial of US therapy in the lower extremities of human subjects with intermittent claudication. METHODS: 10 subjects (5 male, 5 female, mean age 69.7 ± 10.3) with intermittent claudication were recruited. Both legs were placed in a specially designed boot with a water interface between US transducers and the legs. Subjects underwent pulsed US therapy at 250 kHz frequency for 30 min for three treatments a week for six weeks. Pre and post treatment ankle:brachial index (ABI), 6-min walk (6 MW), Walking Impairment Questionnaire (WIQ), and Short Form 36 (SF36) were performed. Pre and post-treatment results were compared with paired t-test. RESULTS: Six minute walking distance at baseline was 352 ± 70 m, after one treatment session 353 ± 70 m (p = 0.99), and at completion 372 ± 71 m (p = 0.015). There was a trend toward improved ABI after 6 weeks of treatment (0.53 ± 0.17 vs 0.64 ± 0.12, p = 0.083). After six weeks, significant improvements were noted in overall WIQ score (2.00 ± 1.48 vs 2.63 ± 1.38, p = 0.0001), WIQ (distance) 2.07 ± 1.54 vs 2.73 ± 1.42 (p = 0.036), and WIQ (stair) 2.00 ± 1.67 vs 2.62 ± 1.24, p = 0.034, with a trend in WIQ (speed), 1.89 ± 1.26 vs 2.46 ± 1.43, p = 0.069. In the SF-36, significant improvements were noted in the domains of physical functioning (44.0 ± 41.6 vs 50.5 ± 41.1, p = 0.009) and role limitations - physical (35.0 ± 48.3 vs 60.0 ± 49.6, p = 0.006) after six weeks. CONCLUSIONS: Therapeutic US is a potential noninvasive treatment for intermittent claudication. Pilot study patients noted significant improvements in 6 MW and WIQ results after 6 weeks of treatment. A nonsignificant improvement in ABI was noted. Further research will be needed to clarify optimal treatment frequency and duration.

How patients interpret early signs of foot problems and reasons for delays in care: Findings from interviews with patients who have undergone toe amputations.

AIMS: To describe how patients respond to early signs of foot problems and the factors that result in delays in care. METHODS: Semi-structured interviews were conducted with a large sample of Veterans from across the United States with diabetes mellitus who had undergone a toe amputation. Data were analyzed using inductive content analysis. RESULTS: We interviewed 61 male patients. Mean age was 66 years, 41% were married, and 37% had a high school education or less. The patient-level factors related to delayed care included: 1) not knowing something was wrong, 2) misinterpreting symptoms, 3) "sudden" and "unexpected" illness progression, and 4) competing priorities getting in the way of care-seeking. The system-level factors included: 5) asking patients to watch it, 6) difficulty getting the right type of care when needed, and 7) distance to care and other transportation barriers. CONCLUSION: A confluence of patient factors (e.g., not examining their feet regularly or thoroughly and/or not acting quickly when they noticed something was wrong) and system factors (e.g., absence of a mechanism to support patient's appraisal of symptoms, lack of access to timely and convenient-located appointments) delayed care. Identifying patient- and system-level interventions that can shorten or eliminate care delays could help reduce rates of limb loss.

Immediate effects of hemodialysis on upper extremity and cognitive function.

BACKGROUND: Subjects undergoing hemodialysis often describe feeling "weak" and "fatigued" after dialysis. This has not previously been quantified. We sought to evaluate upper extremity and cognitive function before and after hemodialysis to see if differences existed and how long recovery takes. METHODS: Subjects undergoing hemodialysis in an inpatient hospital dialysis unit were recruited. Subjects underwent assessment of upper extremity strength (grip (GS) and pinch (PS)), dexterity (pegboard assembly (PA)), finger sensation (monofilaments), and cognitive function (mini-mental status exam (MMS)) immediately pre- and post-dialysis, 3 h post-dialysis, and the following morning. Both the dialysis (index) and non-dialysis extremities were evaluated. Results were also stratified for fistulas vs. central venous catheters. Patients were dialyzed at the same flow rate and duration. RESULTS: 21 subjects were evaluated, 13 (62%), male, mean age 56 ± 17 years, 15 (71%) diabetic, 15 (71%) fistulas, 6 (29%) central venous catheters. Overall, there were no significant changes in GS, PS, PA, immediately or 3 h after dialysis. MMS was non-significantly reduced 3 h after dialysis (22.8 ± 10.3 vs 27.0 ± 3.5, p = 0.06). PA was significantly improved the following morning (6.4 ± 4.8 assembled units vs 7.5 ± 5.1, p = 0.049). Patients dialyzing through catheters had reduced grip strength 3 h after dialysis compared to fistulas (-4.6 ± 2.7 N from baseline vs 1.4 ± 4.3 N from baseline, p = 0.018) that was resolved by the next day. CONCLUSIONS: Hemodialysis in hospitalized inpatients does not cause acute objective deficits in upper extremity or cognitive function, with a significant improvement in hand dexterity the day after dialysis.

Improving follow-up of incomplete lower extremity venous duplex ultrasound examinations performed for deep and superficial vein thromboses.

OBJECTIVE: A lower extremity venous duplex ultrasound (LEVDUS) examination is the standard diagnostic test to evaluate patients for lower extremity deep vein thrombosis (DVT). However, some studies will be incomplete for a variety of reasons, including patient-related factors such as pain, edema, a large leg circumference, or the presence of overlying bandages or orthopedic devices. We previously reported that the frequency of obtaining a follow-up examination after an incomplete and negative (I/N) LEVDUS examination was low but that the rates of DVT found on the follow-up studies of initially I/N LEVDUS studies were similar to the rates of DVT found with initially complete LEVDUS examinations. Therefore, we recommended process improvements to increase follow-up LEVDUS studies after an I/N LEVDUS examination. In the present study, we have described the results of appending a recommendation to obtain a follow-up LEVDUS study to preliminary and final reports of I/N LEVDUS. METHODS: Starting in January 2019 through December 2019, a recommendation to obtain a repeat LEVDUS examination after an I/N study was appended to the preliminary and final reports of all I/N LEVDUS examination of patients who did not, otherwise, have an indication for anticoagulation (group 2). The patients were identified on an ongoing basis through the study period and entered into an Excel database (Microsoft Corp, Redmond, Wash). Group 2 was compared with a previously reported historic control cohort of patients identified from January 2017 to December 2017 (group 1). We compared groups 1 and 2 with respect to the frequency of the repeat studies performed within 4 weeks after an I/N LEVDUS examination and the DVT rates found from the follow-up LEVDUS examinations after an I/N LEVDUS study. RESULTS: Of the patients in groups 1 and 2, 187 and 229 had had I/N LEVDUS examinations, with 28% and 40.2% of group 1 and 2 studies having follow-up LEVDUS examinations (P < .01). Previously unidentified lower extremity thrombi were discovered in 21% of the group 2 follow-up examinations. Also, the rate of new thrombi detected was not different between groups 2 and 1 (historic controls; DVT, 14.3% vs 18.5% [P = .25]; SVT, 6.3% vs 3.3% [P = .15]). A definitive finding of either positive or negative for DVT and SVT with a complete examination in 50% of the group 2 patients with follow-up examinations. CONCLUSIONS: A recommendation to obtain a follow-up examination appended to the preliminary and final I/N LEVDUS reports was associated with an increased rate of follow-up examinations, which revealed many previously undetected DVTs and SVTs or had allowed for definitive exclusion of DVT.

Peak systolic velocity and color aliasing are important in the development of duplex ultrasound criteria for external carotid artery stenosis.

OBJECTIVE: The external carotid artery (ECA) serves as a major collateral pathway for ophthalmic and cerebral artery blood supply. It is routinely examined as part of carotid duplex ultrasound, but criteria for determining ECA stenosis are poorly characterized and typically extrapolated from internal carotid artery data. This is despite the fact that the ECA is smaller in diameter, with a higher resistance and lower volume flow pattern. We hypothesized that using the cutoff of a peak systolic velocity (PSV) ≥125 cm/s, extrapolated from internal carotid artery data, will overestimate the prevalence of ≥50% ECA stenosis and aimed to determine a more appropriate criterion. METHODS: From December 2016 to July 2017, consecutive carotid duplex ultrasound studies performed in our university hospital Intersocietal Accreditation Commission-accredited vascular laboratory were prospectively identified and categorized with respect to prevalence and distribution of ECA PSVs and color aliasing, an indication of turbulent flow or flow acceleration. Presence of color aliasing was determined by two individual reviewers and agreement assessed by Cohen κ coefficient. ECA stenosis was calculated by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method in patients with computed tomography angiography (CTA) performed within 3 months of carotid duplex ultrasound without an intervening intervention. Receiver operating characteristic analysis was performed to identify best criteria for determining ≥50% ECA stenosis. RESULTS: There were 1324 ECAs from 662 patients analyzed; 174 patients had a total of 252 ECAs with PSV ≥125 cm/s (19% of the total sample). Of those ECAs with PSVs ≥125 cm/s, 30.5% were between 125 and 149 cm/s, 22.2% were between 150 and 174 cm/s, 13.1% were between 175 and 199 cm/s, and 34.1% were ≥200 cm/s. There were 341 ECAs that were analyzed for the presence of color aliasing. In 86 ECAs with PSV ≥200 cm/s, 58.1% had color aliasing, whereas in 255 ECAs with PSV <200 cm/s, only 19.2% had color aliasing (P = .0001). There were 325 CTA studies reviewed and assessed for the presence of a ≥50% ECA stenosis as determined by CTA. Overall, the combination of an ECA PSV ≥200 cm/s with the presence of color aliasing provided the highest combination of sensitivity (90%), specificity (96%), positive predictive value (83%), and negative predictive value (98%) and the greatest area under the curve of 0.971 for determining the presence of a ≥50% ECA stenosis based on CTA. CONCLUSIONS: A PSV ≥125 cm/s alone probably overestimates the prevalence of ≥50% ECA stenosis. A PSV ≥200 cm/s combined with color aliasing is highly predictive of >50% ECA stenosis based on correlation with CTA.

Experienced operators achieve superior patency and wound complication rates with endoscopic great saphenous vein harvest compared with open harvest in lower extremity bypasses.

OBJECTIVE: Prior studies have suggested improved wound complication rates but decreased primary patency in lower extremity bypasses performed with endoscopic vein harvest (EVH) vs open vein harvest (OVH). We hypothesize that the inferior patency reflects the initial learning curve for EVH and that improved patency can be achieved with experience. METHODS: This was a single-institution review of 113 patients with critical limb ischemia who underwent infrainguinal bypass with a continuous segment of great saphenous vein harvested endoscopically (n = 49) or through a single open incision (n = 64) from 2012 to 2017. EVH was performed by surgeons with >5 years' experience with this technique. Operative outcomes, patency, complications, and readmission rates were compared between the harvest methods. EVH data were also compared with our prior reported series of our initial experience with this technique to determine the effects of experience on outcomes. RESULTS: There were no significant differences in patient demographics, medications, operative indications, or inflow/outflow vessels between the two groups. Mean operative time was 322 minutes and median hospital length of stay was 6 days for OVH, and was 340 minutes and 5 days for EVH, which was not significant. Harvest-related wound complications were more frequent with OVH (28% vs 2%, P < .001). Primary patency at 1 and 3 years was 65% and 58% for OVH, and 79% and 71% for EVH, respectively (P = .18), assisted primary patency was 77% and 74% for OVH and 94% and 89% for EVH, respectively (P = .05), and secondary patency was 82% and 79% for OVH and 95% and 95% for EVH, respectively (P = .03). The 30-day readmission rates were similar between OVH (20%) and EVH (12%, P = .26), but 90-day readmissions were more frequent in the OVH group (34% vs 14%, P = .018). Compared with our earlier series of EVH, the current cohort had significantly improved 3-year primary (71% vs 42%, P = .012), primary assisted patency (89 vs 66%, P = .034), and secondary patency (95% vs 66%, P = .003). CONCLUSIONS: With experience, lower extremity bypass using EVH can result in improved patency compared with OVH and initial EVH use, while also resulting in fewer wound complications and readmissions, with comparable operative times and hospital length of stay. This technique should be more widely adopted by vascular surgeons as a primary method of vein harvest.

Predictors of perioperative morbidity and mortality in open abdominal aortic aneurysm repair.

INTRODUCTION: The major advantage of endovascular abdominal aortic aneurysm repair (EVAR) over open repair (OAR) is improved perioperative morbidity and mortality. Long term results of the two modalities are comparable. We sought to quantify factors predicting perioperative morbidity and mortality in patients undergoing OAR. METHODS: Consecutive non-ruptured OAR were analyzed for patient demographic factors, perioperative variables including blood pressure, temperature, and glucose control, intraoperative factors, and complications including wound, pulmonary, renal and cardiac, and 30-day mortality. Uni- and multivariate analysis was performed to determine predictors of morbidity and mortality. RESULTS: 240 elective open AAA repairs over 10 consecutive years were performed. 46% required suprarenal clamping. At least one complication occurred in 47% and 30-day mortality was 5.4%. By multivariate analysis, independent predictors of morbidity (any complication) were suprarenal clamping (OR 1.8, 95% CI 1.1-3.2, p = 0.029), operative time (OR 1.005, 95% CI 1.002-1.008, p = 0.002), and low postoperative temperature (OR 1.6, 95% CI 1.1-2.3, p = 0.025). Multivariate predictors of 30 day mortality included advanced age (OR 1.2, 95% CI 1.1-1.3, p = 0.002) and operative time (OR 1.007, 95% CI 1.001-1.013, p = 0.024). Glucose control did not predict morbidity or mortality. CONCLUSIONS: Control of postoperative temperature is a potentially modifiable factor that may reduce morbidity in patients undergoing open AAA repair, thereby minimizing the early advantage of EVAR.

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.

Interhospital vascular surgery transfers to a tertiary care hospital.

OBJECTIVE: Interhospital transfers (IHTs) to tertiary care centers are linked to lower operative mortality in vascular surgery patients. However, IHT incurs great health care costs, and some transfers may be unnecessary or futile. In this study, we characterize the patterns of IHT at a tertiary care center to examine appropriateness of transfer for vascular surgery care. METHODS: A retrospective review was performed of all IHT requests made to our institution from July 2014 to October 2015. Interhospital physician communication and reasons for not accepting transfers were reviewed. Diagnosis, intervention, referring hospital size, and mortality were examined. Follow-up for all patients was reviewed. RESULTS: We reviewed 235 IHT requests for vascular surgical care involving 210 patients during 15 months; 33% of requested transfers did not occur, most commonly after communication with the physician resulting in reassurance (35%), clinic referral (30%), or further local workup obviating need for transfer (11%); 67% of requests were accepted. Accepted transfers generally carried life- or limb-threatening diagnoses (70%). Next most common transfer reasons were infection or nonhealing wounds (7%) and nonurgent postoperative complications (7%). Of accepted transfers, 72% resulted in operative or endovascular intervention; 20% were performed <8 hours of arrival, 12% <24 hours of arrival, and 68% during hospital admission (average of 3 days); 28% of accepted patients received no intervention. Small hospitals (<100 beds) were more likely than large hospitals (>300 beds) to transfer patients not requiring intervention (47% vs 18%; P = .005) and for infection or nonhealing wounds (30% vs 10%; P = .013). Based on referring hospital size, there was no difference in IHTs requiring emergent, urgent, or nonurgent operations. There was also no difference in transport time, time from consultation to arrival, or death of patients according to hospital size. Overall patient mortality was 12%. CONCLUSIONS: Expectedly, most vascular surgery IHTs are for life- or limb-threatening diagnoses, and most of these patients receive an operation. Transfer efficiency and surgical case urgency are similar across hospital sizes. Nonoperative IHTs are sent more often by small hospitals and may represent a resource disparity that would benefit from regionalizing nonurgent vascular care.

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.