Effect of Two Years of Doxycycline Treatment on Infrarenal Aortic Neck Diameter.

Objective: Endovascular aneurysm repair (EVAR) is a widely used option for patients with suitable vascular anatomy who have a large infrarenal abdominal aortic aneurysm (AAA). Neck diameter is the primary anatomical determinant of EVAR eligibility and device durability. Doxycycline has been proposed to stabilise the proximal neck after EVAR. This study explored doxycycline mediated aortic neck stabilisation in patients with small AAA, monitored by computed tomography over two years. Methods: This was a multicentre prospective randomised clinical trial. Subjects from the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT, NCT01756833) were included in this secondary a priori analysis. Female baseline AAA maximum transverse diameter was between 3.5 and 4.5 cm, and male was between 3.5 and 5.0 cm. Subjects were included if they completed pre-enrolment and two year follow up computed tomography (CT) imaging. Proximal aortic neck diameter was measured at the lowest renal artery, and 5, 10, and 15 mm caudal to this point; mean neck diameter was calculated from these values. Unpaired, two tailed parametric t test analysis with post hoc Bonferroni correction was used to detect differences between neck diameters in subjects treated with placebo vs. doxycycline at baseline and two years. Results: One hundred and ninety-seven subjects (171 male, 26 female) were included in the analysis. All patients, regardless of treatment arm, demonstrated larger neck diameter caudally, a slight increase in diameter at all anatomical levels over time, and greater growth caudally. There was no statistically significant difference in infrarenal neck diameter between treatment arms at any anatomical level at any time point, nor mean change in neck diameter over two years. Conclusion: Doxycycline does not demonstrate infrarenal aortic neck growth stabilisation in small AAA followed for two years by thin cut CT imaging using a standardised acquisition protocol and cannot be recommended for mitigation of growth of the aortic neck in patients with untreated small abdominal aortic aneurysms.

The "two-cut monorail" technique, for the over-the-wire removal of the Impella CP device.

The Impella is a percutaneously placed intra-arterial flow pump positioned across the aortic valve for circulatory support. A limitation of the Impella is that it lacks a central wire channel, to maintain intra-arterial wire access when removing the device. Open surgical arterial cutdown is needed for the removal of the Impella CP placed emergently, without the use of preclose sutures. This case review describes an alternative removal method for the aforementioned occasions.

Dysregulation of FOXO1 (Forkhead Box O1 Protein) Drives Calcification in Arterial Calcification due to Deficiency of CD73 and Is Present in Peripheral Artery Disease.

OBJECTIVE: The recessive disease arterial calcification due to deficiency of CD73 (ACDC) presents with extensive nonatherosclerotic medial layer calcification in lower extremity arteries. Lack of CD73 induces a concomitant increase in TNAP (tissue nonspecific alkaline phosphatase; ALPL), a key enzyme in ectopic mineralization. Our aim was to investigate how loss of CD73 activity leads to increased ALPL expression and calcification in CD73-deficient patients and assess whether this mechanism may apply to peripheral artery disease calcification. Approach and Results: We previously developed a patient-specific disease model using ACDC primary dermal fibroblasts that recapitulates the calcification phenotype in vitro. We found that lack of CD73-mediated adenosine signaling reduced cAMP production and resulted in increased activation of AKT. The AKT/mTOR (mammalian target of rapamycin) axis blocks autophagy and inducing autophagy prevented calcification; however, we did not observe autophagy defects in ACDC cells. In silico analysis identified a putative FOXO1 (forkhead box O1 protein) binding site in the human ALPL promoter. Exogenous AMP induced FOXO1 nuclear localization in ACDC but not in control cells, and this was prevented with a cAMP analogue or activation of A2a/2b adenosine receptors. Inhibiting FOXO1 reduced ALPL expression and TNAP activity and prevented calcification. Mutating the FOXO1 binding site reduced ALPL promoter activation. Importantly, we provide evidence that non-ACDC calcified femoropopliteal arteries exhibit decreased CD73 and increased FOXO1 levels compared with control arteries. CONCLUSIONS: These data show that lack of CD73-mediated cAMP signaling promotes expression of the human ALPL gene via a FOXO1-dependent mechanism. Decreased CD73 and increased FOXO1 was also observed in more common peripheral artery disease calcification.

Transesophageal Echocardiogram-Guided Stent Placement in Superior Vena Cava Syndrome Secondary to Granulomatous Lung Disease: A Case Series and Literature Review.

Obstruction of the superior vena cava (SVC) is an uncommon, but potentially life-threatening condition due to likely development of edema in the head and neck and potential respiratory compromise. Less than half of those affected by SVC syndrome survive more than a year. Obstruction can be from neoplasms or secondary to benign disease. Treatment for most cases of symptomatic SVC syndrome involves placement of a stent to relieve the stenosis. Serious complications such as stent migration, pulmonary embolism, and cardiac tamponade can occur in 5% to 10% of cases, and inadequate imaging of the SVC-atrial junction by fluoroscopy contributes to these problems. The overlapping contrast in the atrium makes it difficult to precisely place the distal end of the stent, potentially allowing for embolization of the stent to occur. We present a case series of 3 patients wherein transesophageal echocardiography was used for guidance of stent placement in the SVC and significantly aided in placement.

Outcomes of Aortic Surgery for Abdominal Aortic Graft Infections.

BACKGROUND: Literature on postoperative outcomes following aortic surgery for aortic graft infection (AGI) is limited by relatively small sample sizes, resulting in lack of national benchmarks for quality of care. We report in-hospital outcomes following abdominal aortic surgery for AGI and identify factors associated with postoperative complications using the Nationwide Inpatient Sample (NIS) database. METHODS: Patients who underwent aortic graft resection for AGI were identified from the 2002 to 2008 NIS database, a multicenter database capturing 20% of all US admissions. Multivariable logistic regression analyses were performed. RESULTS: Among 394 patients (men: 73.4%) who underwent abdominal aortic surgery for AGI, 53% of the admissions were emergent/urgent. A significant trend for decreasing number of abdominal aortic surgery for AGIs per year was observed (Pearson r correlation: -.96; P = .0006). Over the same time span, a significant correlation was also seen with decrease in open and increase in endovascular aortic aneurysm repairs in the NIS database. In-hospital rates of overall postoperative morbidity and mortality were 68.3% and 19.8%, respectively. In-hospital rates of postoperative respiratory failure, renal failure, and cardiac arrest were 35.5%, 14.2%, and 8.9%, respectively. Median length of stay was 26 days, with median hospital charges being US$184 162. On multivariable analysis, increase in age per year (odds ratio [OR] 1.07; 95% confidence interval [CI]: 1.03-1.12) was independently associated with postoperative morbidity, while higher hospital volume for this procedure was protective (OR: 0.71; 95% CI: 0.56-0.89). No preoperative factors were independently associated with postoperative mortality. CONCLUSION: Incidence of abdominal aortic surgery for AGI has progressively declined over the span of our study in association with decreased open and increased endovascular aortic aneurysm repairs. Aortic surgery for AGI is associated with very high morbidity and mortality rates along with prolonged lengths of stay and elevated hospital charges. The outcomes of operations for AGI are better in younger patients and higher volume hospitals.

Morphometric roadmaps to improve accurate device delivery for fluoroscopy-free resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: Uncontrolled hemorrhage from vessel injuries within the torso remains a significant source of prehospital trauma mortality. Resuscitative endovascular balloon occlusion of the aorta can effectively control noncompressible hemorrhage, but this minimally invasive technique relies heavily on imaging not available in the field. Our goal was to develop morphometric roadmaps to enhance the safety and accuracy of fluoroscopy-free endovascular navigation of hemorrhage control devices. METHODS: Three-dimensional reconstructions of computed tomographic angiography scans from 122 trauma patients (mean [SD] age, 47 [24] years; range 5-93 years; 64 males; 58 females) were used to measure centerline distances from femoral artery access sites to the major aortic branch artery origins. Morphometric roadmap equations were created using multiple linear regression analysis to predict distances to the origins of the major arteries in the chest, abdomen, and pelvis using torso length, demographics, and risk factors as independent variables. A 40-mm-long occlusion balloon was then virtually deployed targeting Zones 1 and 3 of the aorta using these equations. Balloon placement accuracy was determined by comparing predicted versus actual measured distances to the target zone locations within the aortas from the database. RESULTS: Torso length and age were the strongest predictors of centerline distances from femoral artery access sites to the major artery origins. Male sex contributed to longer distances, while diabetes and smoking were associated with shorter distances. Hypertension, dyslipidemia, and coronary artery disease had no effect. With the use of morphometric roadmaps, virtual occlusion balloon placement accuracy was 100% for Zone 3 of the aorta, compared with 87% accuracy when using torso length alone. CONCLUSION: Morphometric roadmaps demonstrate a potential for improving the safety and accuracy of fluoroscopy-free aortic occlusion balloon delivery. Continued development of minimally invasive hemorrhage control techniques holds promise to improve prehospital mortality for patients with noncompressible exsanguinating torso injuries. LEVEL OF EVIDENCE: Therapeutic study, level IV; diagnostic study, level III.

Effects of age on the physiological and mechanical characteristics of human femoropopliteal arteries.

Surgical and interventional therapies for peripheral artery disease (PAD) are notorious for high rates of failure. Interactions between the artery and repair materials play an important role, but comprehensive data describing the physiological and mechanical characteristics of human femoropopliteal arteries are not available. Fresh femoropopliteal arteries were obtained from 70 human subjects (13-79 years old), and in situ vs. excised arterial lengths were measured. Circumferential and longitudinal opening angles were determined for proximal superficial femoral, proximal popliteal and distal popliteal arteries. Mechanical properties were assessed by multi-ratio planar biaxial extension, and experimental data were used to calculate physiological stresses and stretches, in situ axial force and anisotropy. Verhoeff-Van Gieson-stained axial and transverse arterial sections were used for histological analysis. Most specimens demonstrated nonlinear deformations and were more compliant longitudinally than circumferentially. In situ axial pre-stretch decreased 0.088 per decade of life. In situ axial force and axial stress also decreased with age, but circumferential physiological stress remained constant. Physiological circumferential stretch decreased 55-75% after 45 years of age. Histology demonstrated a thickened external elastic lamina with longitudinally oriented elastin that was denser in smaller, younger arteries. Axial elastin likely regulates axial pre-stretch to help accommodate the complex deformations required of the artery wall during locomotion. Degradation and fragmentation of elastin as a consequence of age, cyclic mechanical stress and atherosclerotic arterial disease may contribute to decreased in situ axial pre-stretch, predisposing to more severe kinking of the artery during limb flexion and loss of energy-efficient arterial function.

Age and disease-related geometric and structural remodeling of the carotid artery.

BACKGROUND: Carotid artery geometry has been suggested as a risk factor for atherosclerotic carotid artery disease (ACD). Although normal aging and development of disease can both lead to geometric changes in the artery, whether geometric changes in a given artery actually predispose to disease or are just a consequence of remodeling during aging is unclear. We investigated carotid artery geometric changes with aging to identify geometric features associated with the presence of ACD. METHODS: Carotid artery geometry was quantified by measuring carotid artery diameter, tortuosity, and bifurcation angle using three-dimensional reconstructions of thin-section computed tomography angiography scans in 15 healthy individuals (average age, 43 ± 18 years; range, 15-64 years). The same geometric features were measured in 17 patients (68 ± 10 years old) with unilateral ACD. Geometric features associated with presence of ACD were determined by using the nondiseased contralateral carotid artery as an intrinsic control. Elastin-stained carotid arteries were analyzed to assess age-related structural changes in 12 deceased individuals. RESULTS: Increases were noted in bulb diameter (0.64 mm), bifurcation angle (10°), and tortuosity of the common carotid (CCA; 0.03) and internal carotid arteries (ICA; 0.04) for every decade of life. Density and continuity of circumferential and longitudinal elastin in the CCA and ICA decreased with age. Compared with normal carotid arteries, those with ACD demonstrated larger bulb diameters (P = .001) but smaller bifurcation angles (P = .001). CCA tortuosity (P = .038) increased in ACD arteries compared with normal carotid arteries, but ICA tortuosity was decreased (P = .026). CONCLUSIONS: With increasing age, bulb diameter, tortuosity, and bifurcation angle increases in carotid arteries. These geometric changes may be related to degradation and fragmentation of intramural elastin. Arteries with atherosclerotic occlusive disease demonstrate decreased ICA tortuosity and smaller bifurcation angles compared with nondiseased carotid arteries.

Three-dimensional bending, torsion and axial compression of the femoropopliteal artery during limb flexion.

High failure rates of femoropopliteal artery reconstruction are commonly attributed to complex 3D arterial deformations that occur with limb movement. The purpose of this study was to develop a method for accurate assessment of these deformations. Custom-made stainless-steel markers were deployed into 5 in situ cadaveric femoropopliteal arteries using fluoroscopy. Thin-section CT images were acquired with each limb in the straight and acutely bent states. Image segmentation and 3D reconstruction allowed comparison of the relative locations of each intra-arterial marker position for determination of the artery's bending, torsion and axial compression. After imaging, each artery was excised for histological analysis using Verhoeff-Van Gieson staining. Femoropopliteal arteries deformed non-uniformly with highly localized deformations in the proximal superficial femoral artery, and between the adductor hiatus and distal popliteal artery. The largest bending (11±3-6±1 mm radius of curvature), twisting (28±9-77±27°/cm) and axial compression (19±10-30±8%) were registered at the adductor hiatus and the below knee popliteal artery. These deformations were 3.7, 19 and 2.5 fold more severe than values currently reported in the literature. Histology demonstrated a distinct sub-adventitial layer of longitudinally oriented elastin fibers with intimal thickening in the segments with the largest deformations. This endovascular intra-arterial marker technique can quantify the non-uniform 3D deformations of the femoropopliteal artery during knee flexion without disturbing surrounding structures. We demonstrate that 3D arterial bending, torsion and compression in the flexed lower limb are highly localized and are substantially more severe than previously reported.

Biaxial mechanical properties of the human thoracic and abdominal aorta, common carotid, subclavian, renal and common iliac arteries.

The biomechanics of large- and medium-sized arteries influence the pathophysiology of arterial disease and the response to therapeutic interventions. However, a comprehensive comparative analysis of human arterial biaxial mechanical properties has not yet been reported. Planar biaxial extension was used to establish the passive mechanical properties of human thoracic (TA, [Formula: see text]) and abdominal (AA, [Formula: see text]) aorta, common carotid (CCA, [Formula: see text]), subclavian (SA, [Formula: see text]), renal (RA, [Formula: see text]) and common iliac (CIA, [Formula: see text]) arteries from 11 deceased subjects ([Formula: see text] years old). Histological evaluation determined the structure of each specimen. Experimental data were used to determine constitutive parameters for a structurally motivated nonlinear anisotropic constitutive model. All arteries demonstrated appreciable anisotropy and large nonlinear deformations. Most CCA, SA, TA, AA and CIA specimens were stiffer longitudinally, while most RAs were stiffer circumferentially. A switch in anisotropy was occasionally demonstrated for all arteries. The CCA was the most compliant, least anisotropic and least frequently diseased of all arteries, while the CIA and AA were the stiffest and the most diseased. The severity of atherosclerosis correlated with age, but was not affected by laterality. Elastin fibers in the aorta, SA and CCA were uniformly and mostly circumferentially distributed throughout the media, while in the RA and CIA, elastin was primarily axially aligned and concentrated in the external elastic lamina. Constitutive modeling provided good fits to the experimental data for most arteries. Biomechanical and architectural features of major arteries differ depending on location and functional environment. A better understanding of localized arterial mechanical properties may support the development of site-specific treatment modalities for arterial disease.

Passive biaxial mechanical properties and in vivo axial pre-stretch of the diseased human femoropopliteal and tibial arteries.

Surgical and interventional therapies for atherosclerotic lesions of the infrainguinal arteries are notorious for high rates of failure. Frequently, this leads to expensive reinterventions, return of disabling symptoms or limb loss. Interaction between the artery and repair material likely plays an important role in reconstruction failure, but data describing the mechanical properties and functional characteristics of human femoropopliteal and tibial arteries are currently not available. Diseased superficial femoral (SFA, n = 10), popliteal (PA, n = 8) and tibial arteries (TA, n = 3) from 10 patients with critical limb ischemia were tested to determine passive mechanical properties using planar biaxial extension. All specimens exhibited large nonlinear deformations and anisotropy. Under equibiaxial loading, all arteries were stiffer in the circumferential direction than in the longitudinal direction. Anisotropy and longitudinal compliance decreased distally, but circumferential compliance increased, possibly to maintain a homeostatic multiaxial stress state. Constitutive parameters for a four-fiber family invariant-based model were determined for all tissues to calculate in vivo axial pre-stretch that allows the artery to function in the most energy efficient manner while also preventing buckling during extremity flexion. Calculated axial pre-stretch was found to decrease with age, disease severity and more distal arterial location. Histological analysis of the femoropopliteal artery demonstrated a distinct sub-adventitial layer of longitudinal elastin fibers that appeared thicker in healthier arteries. The femoropopliteal artery characteristics and properties determined in this study may assist in devising better diagnostic and treatment modalities for patients with peripheral arterial disease.

A mathematical evaluation of hemodynamic parameters after carotid eversion and conventional patch angioplasty.

Carotid endarterectomy has a long history in stroke prevention, yet controversy remains concerning optimal techniques. Two methods frequently used are endarterectomy with patch angioplasty (CEAP) and eversion endarterectomy (CEE). The objective of this study was to compare hemodynamics-related stress and strain distributions between arteries repaired using CEAP and CEE. Mathematical models were based on in vivo three-dimensional arterial geometry, pulsatile velocity profiles, and intraluminal pressure inputs obtained from 16 patients with carotid artery disease. These data were combined with experimentally derived nonlinear, anisotropic carotid artery mechanical properties to create fluid-structure interaction models of CEAP and CEE. These models were then used to calculate hemodynamic parameters thought to promote recurrent disease and restenosis. Combining calculations of stress and strain into a composite risk index, called the integral abnormality factor, allowed for an overall comparison between CEAP and CEE. CEE demonstrated lower mechanical stresses in the arterial wall, whereas CEAP straightened the artery and caused high stress and strain concentrations at the suture-artery interface. CEAP produced a larger continuous region of oscillatory, low-shear, vortical flow in the carotid bulb. There was a more than two-fold difference in the integral abnormality factor, favoring CEE. In conclusion, in a realistically simulated carotid artery, fluid-structure interaction modeling demonstrated CEE to produce less mechanical wall stress and improved flow patterns compared with CEAP. Clinical validation with larger numbers of individual patients will ultimately be required to support modeling approaches to help predict arterial disease progression and comparative effectiveness of reconstruction methods and devices.

Development of a risk index for prediction of mortality after open aortic aneurysm repair.

OBJECTIVE: Open infrarenal abdominal aortic aneurysm (oAAA) repair is associated with significant morbidity and mortality. Although there has been a shift toward endovascular repair, many patients continue to undergo an open repair due to anatomic considerations. Tools currently existing for estimation of periprocedural risk in patients undergoing open aortic surgery have certain limitations. The objective of this study was to develop a risk index to estimate the risk of 30-day perioperative mortality after elective oAAA repair. METHODS: Patients who underwent elective oAAA repair (n = 2845) were identified from the American College of Surgeons' 2007 to 2009 National Surgical Quality Improvement Program (NSQIP), a prospective database maintained at >250 centers. Univariable and multivariable analyses were performed to evaluate risk factors associated with 30-day mortality after oAAA repair and a risk index was developed. RESULTS: The 30-day mortality after oAAA repair was 3.3%. Multivariable analysis identified six preoperative predictors of mortality, and a risk index was created by assigning weighted points to each predictor using the ß-coefficients from the regression analysis. The predictors included dyspnea (at rest: 8 points; on moderate exertion: 2 points; none: 0 points), history of peripheral arterial disease requiring revascularization or amputation (3 points), age >65 years (3 points), preoperative creatinine >1.5 mg/dL (2 points), female gender (2 points), and platelets <150,000/mm(3) or >350,000/mm(3) (2 points). Patients were classified as low (<7%), intermediate (7%-15%), and high (>15%) risk for 30-day mortality based on a total point score of <8, 8 to 11, and >11, respectively. There were 2508 patients (88.2%) patients in the low-risk category, 278 (9.8%) in the intermediate-risk category, and 59 (2.1%) in the high-risk category. CONCLUSIONS: This risk index has excellent predictive ability for mortality after oAAA repair and awaits validation in subsequent studies. It is anticipated to aid patients and surgeons in informed patient consent, preoperative risk assessment, and optimization.

Effects of carotid artery stenting on arterial geometry.

BACKGROUND: The role of carotid artery stenting (CAS) for the treatment of carotid artery disease continues to evolve, despite higher stroke and restenosis risks for CAS compared with conventional open endarterectomy. Understanding the effects of CAS on arterial geometry, which strongly influence hemodynamics and wall mechanics, can assist in better stratifying the inherent risk of CAS to individual patients. STUDY DESIGN: Fifteen consecutive patients undergoing CAS had pre- and post-stenting CT angiograms. These images were used to reconstruct the 3-dimensional geometries of the bilateral carotid arteries from their origin to the skull base. Quantitative assessment of the carotid bifurcation angle, cross-sectional area, tortuosity and artery length, were compared pre- and post-stenting. Plaque volume and calcification were also measured. Mathematical models were devised to determine the mechanisms of CAS-induced geometric changes, and their mechanical and hemodynamic significances. RESULTS: Major and moderate changes in arterial tortuosity and elongation were seen in 5 (33%) patients. Characteristics most associated with the development of CAS-induced geometric changes were stenoses located in the internal carotid artery distal to the carotid bulb, circumferential distribution of plaque, and plaque calcification. Modeling did not demonstrate substantial alterations in wall shear stress due to geometric changes, but did show considerable increases in arterial wall axial stress. CONCLUSIONS: Carotid artery stenting can produce geometric changes to the artery that promote favorable conditions for complications and recurrent disease. Patients with circumferential, highly calcified plaques that are located relatively distal in the internal carotid artery are most likely to have post-stenting geometric changes.

Preoperative anemia is an independent predictor of postoperative mortality and adverse cardiac events in elderly patients undergoing elective vascular operations.

OBJECTIVE: The objective of this study was to assess the impact of preoperative anemia (hematocrit <39%) on postoperative 30-day mortality and adverse cardiac events in patients 65 years or older undergoing elective vascular procedures. BACKGROUND: Preoperative anemia is associated with adverse outcomes after cardiac surgery, but its association with postoperative outcomes after open and endovascular procedures is not well established. Elderly patients have a decreased tolerance to anemia and are at high risk for complications after vascular procedures. METHODS: Patients (N = 31,857) were identified from the American College of Surgeons' 2007-2009 National Surgical Quality Improvement Program-a prospective, multicenter (>250) database maintained across the United States. The primary and secondary outcomes of interest were 30-day mortality and a composite end point of death or cardiac event (cardiac arrest or myocardial infarction), respectively. RESULTS: Forty-seven percent of the study population was anemic. Anemic patients had a postoperative mortality and cardiac event rate of 2.4% and 2.3% in contrast to the 1.2% and 1.2%, respectively, in patients with hematocrit within the normal range (P < 0.0001). On multivariate analysis, we found a 4.2% (95% confidence interval, 1.9-6.5) increase in the adjusted risk of 30-day postoperative mortality for every percentage point of hematocrit decrease from the normal range. CONCLUSIONS: The presence and degree of preoperative anemia are independently associated with 30-day death and adverse cardiac events in patients 65 years or older undergoing elective open and endovascular procedures. Identification and treatment of anemia should be important components of preoperative care for patients undergoing vascular operations.

In-hospital and postdischarge venous thromboembolism after vascular surgery.

OBJECTIVE: Recent single-center reports demonstrate a high (up to 10%) incidence of postoperative venous thromboembolism (VTE) after major vascular surgery. Moreover, vascular patients rarely receive prolonged prophylaxis despite evidence that it reduces thromboembolic events after discharge. This study used a national, prospective, multicenter database to define the incidence of overall and postdischarge VTE after major vascular operations and assess risk factors associated with VTE development. METHODS: Patients with VTE who underwent elective vascular procedures (n = 45,548) were identified from the 2007-2009 National Surgical Quality Improvement Program (NSQIP) database. The vascular procedures included carotid endarterectomy (CEA; n = 20,785), open thoracoabdominal aortic aneurysm (TAAA) repair (n = 361), thoracic endovascular aortic repair (TEVAR; n = 732), open abdominal aortic (OAA) surgery (n = 6195), endovascular aneurysm repair (EVAR; n = 7361), and infrainguinal bypass graft (BPG; n = 10,114). Univariable and multivariable analyses were performed to ascertain risk factors associated with VTE. RESULTS: VTE was diagnosed in 187 patients (1.3 %) who underwent aortic surgery, with TAAA repair having the highest rate of VTE (4.2%), followed by TEVAR (2.2%), OAA surgery (1.7%), and EVAR (0.7%). In this subgroup, pulmonary embolisms (PE) were diagnosed in 52 (0.4%) and deep venous thrombosis (DVT) in 144 (1%). VTE rates were 1.0% and 0.2% for patients who underwent a BPG or CEA, respectively. Forty-one percent of all VTEs were diagnosed after discharge. The median (interquartile range) number of days from surgery to PE and DVT were 10 (5-15) and 10 (4-18), respectively. On multivariable analyses, type of surgical procedure, totally dependent functional status, disseminated cancer, postoperative organ space infection, postoperative cerebrovascular accident, failure to wean from ventilator ≤48 hours, and return to the operating room were significantly associated with development of VTE. In those experiencing a DVT or PE, overall mortality increased from 1.5% to 6.2% and from 1.5% to 5.7% respectively (P < .05 for both). CONCLUSIONS: Postoperative VTE is associated with the type of vascular procedure and is highest after operations in the chest and abdomen/pelvis. About 40% of VTE events in elective vascular surgery patients were diagnosed after discharge, and the presence of VTE was associated with a quadrupled mortality rate. Future studies should evaluate the benefit of DVT screening and postdischarge VTE prophylaxis in high-risk patients.

Hemodynamically motivated choice of patch angioplasty for the performance of carotid endarterectomy.

Patch angioplasty is the most common technique used for the performance of carotid endarterectomy. A large number of materials are available, but little is known to aid the surgeon in choosing a patch while caring for a patient with carotid disease. The objective of this study was to investigate biomechanics of the carotid artery (CA) repaired with patch angioplasty, study the influence of patch width and location of closure on hemodynamics, and to select the optimal patch material from those commonly used. For this purpose, a mathematical model was built that accounts for fluid-structure interaction, three-dimensional arterial geometry, non-linear anisotropic mechanical properties, non-Newtonian flow and in vivo boundary conditions. This model was used to study disease-related mechanical factors in the arterial wall and blood flow for different types of patch angioplasty. Analysis indicated that patch closures performed with autologous vein and bovine pericardium were hemodynamically superior to carotid endarterectomy with synthetic patch angioplasty (polytetrafluoroethylene, Dacron) in terms of restenosis potential. Width of the patch and location of arteriotomy were found to be of paramount importance, with narrow patches being superior to wide patches, and anterior arteriotomy being superior to the lateral arteriotomy. These data can aid vascular surgeons in their selection of patch angioplasty technique and material for the care of patients undergoing open CA repair.