An exercise stress test for contrast-enhanced duplex ultrasound assessment of lower limb muscle perfusion in patients with peripheral arterial disease.

OBJECTIVE: The aim of the present study was to develop a standardized contrast-enhanced duplex ultrasound (CE-DUS) protocol to assess lower-extremity muscle perfusion before and after exercise and determine relationships of perfusion with clinical and functional measures. METHODS: CE-DUS (EPIQ 5G, Philips) was used before and immediately after a 10-minute, standardized bout of treadmill walking to compare microvascular perfusion of the gastrocnemius muscle in older (55-82 years) patients with peripheral arterial disease (PAD) (n = 15, mean ankle-brachial index, 0.78 ± 0.04) and controls (n = 13). Microvascular blood volume (MBV) and microvascular flow velocity (MFV) were measured at rest and immediately following treadmill exercise, and the Modified Physical Performance Test (MPPT) was used to assess mobility function. RESULTS: In the resting state (pre-exercise), MBV in patients with PAD was not significantly different than normal controls (5.17 ± 0.71 vs 6.20 ± 0.83 arbitrary units (AU) respectively; P = .36); however, after exercise, MBV was ∼40% lower in patients with PAD compared with normal controls (5.85 ± 1.13 vs 9.53 ± 1.31 AU, respectively; P = .04). Conversely, MFV was ∼60% higher in patients with PAD compared with normal controls after exercise (0.180 ± 0.016 vs 0.113 ± 0.018 AU, respectively; P = .01). There was a significant between-group difference in the exercise-induced changes in both MBV and MFV (P ≤ .05). Both basal and exercise MBV directly correlated with MPPT score in the patients with PAD (r = 0.56-0.62; P < .05). CONCLUSIONS: This standardized protocol for exercise stress testing of the lower extremities quantifies calf muscle perfusion and elicits perfusion deficits in patients with PAD. This technique objectively quantifies microvascular perfusion deficits that are related to reduced mobility function and could be used to assess therapeutic efficacy in patients with PAD.

Computed tomography angiographic biomarkers help identify vulnerable carotid artery plaque.

OBJECTIVE: The current risk assessment for patients with carotid atherosclerosis relies primarily on measuring the degree of stenosis. More reliable risk stratification could improve patient selection for targeted treatment. We have developed and validated a model to predict for major adverse neurologic events (MANE; stroke, transient ischemic attack, amaurosis fugax) that incorporates a combination of plaque morphology, patient demographics, and patient clinical information. METHODS: We enrolled 221 patients with asymptomatic carotid stenosis of any severity who had undergone computed tomography angiography at baseline and ≥6 months later. The images were analyzed for carotid plaque morphology (plaque geometry and tissue composition). The data were partitioned into training and validation cohorts. Of the 221 patients, 190 had complete records available and were included in the present analysis. The training cohort was used to develop the best model for predicting MANE, incorporating the patient and plaque features. First, single-variable correlation and unsupervised clustering were performed. Next, several multivariable models were implemented for the response variable of MANE. The best model was selected by optimizing the area under the receiver operating characteristic curve (AUC) and Cohen's kappa statistic. The model was validated using the sequestered data to demonstrate generalizability. RESULTS: A total of 62 patients had experienced a MANE during follow-up. Unsupervised clustering of the patient and plaque features identified single-variable predictors of MANE. Multivariable predictive modeling showed that a combination of the plaque features at baseline (matrix, intraplaque hemorrhage [IPH], wall thickness, plaque burden) with the clinical features (age, body mass index, lipid levels) best predicted for MANE (AUC, 0.79), In contrast, the percent diameter stenosis performed the worst (AUC, 0.55). The strongest single variable for discriminating between patients with and without MANE was IPH, and the most predictive model was produced when IPH was considered with wall remodeling. The selected model also performed well for the validation dataset (AUC, 0.64) and maintained superiority compared with percent diameter stenosis (AUC, 0.49). CONCLUSIONS: A composite of plaque geometry, plaque tissue composition, patient demographics, and clinical information predicted for MANE better than did the traditionally used degree of stenosis alone for those with carotid atherosclerosis. Implementing this predictive model in the clinical setting could help identify patients at high risk of MANE.

Quantitative assessment of carotid plaque morphology (geometry and tissue composition) using computed tomography angiography.

OBJECTIVE: Quantification of carotid plaque morphology (geometry and tissue composition) may help stratify risk for future stroke and assess plaque progression or regression in response to medical risk factor modification. We assessed the feasibility and reliability of morphologic measurements of carotid plaques using computed tomography angiography (CTA) and determined the minimum detectable change in plaque features by this approach. METHODS: CTA images of both carotid arteries in 50 patients were analyzed by two observers using a semiautomatic image analysis program, yielding 93 observations per user (seven arteries were excluded because of prior stenting). One observer repeated the analyses 4 weeks later. Measurements included total plaque volume; percentage stenosis (by diameter and area); and tissue composition for calcium, lipid-rich necrotic core (LRNC), and intraplaque hemorrhage (IPH). Reliability of measurements was assessed by intraclass and interclass correlation and Bland-Altman plots. Dice similarity coefficient (DSC) and modified Hausdorff distance (MHD) assessed reliability of geometric shape measurements. We additionally computed the minimum amount of change in these features detectable by our approach. RESULTS: The cohort was 51% male (mean age, 70.1 years), and 56% had a prior stroke. The mean (± standard deviation) plaque volume was 837.3 ± 431.3 mm3, stenosis diameter was 44.5% ± 25.6%, and stenosis area was 58.1% ± 29.0%. These measurements showed high reliability. Intraclass correlation coefficients for plaque volume, percentage stenosis by diameter, and percentage stenosis by area were 0.96, 0.87, and 0.83, respectively; interclass correlation coefficients were 0.88, 0.84, and 0.78. Intraclass correlations for tissue composition were 0.99, 0.96, and 0.86 (calcium, LRNC, and IPH, respectively), and interclass correlations were 0.99, 0.92, and 0.92. Shape measurements showed high intraobserver (DSC, 0.95 ± 0.04; MHD, 0.16 ± 0.10 mm) and interobserver (DSC, 0.94 ± 0.05; MHD, 0.19 ± 0.12 mm) luminal agreement. This approach can detect a change of at least 3.9% in total plaque volume, 1.2 mm3 in calcium, 4.3 mm3 in LRNC, and 8.6 mm3 in IPH with the same observer repeating measurements and 9.9% in plaque volume, 1.9 mm3 in calcium, 7.9 mm3 in LRNC, and 6.8 mm3 in IPH for two different observers. CONCLUSIONS: Carotid plaque geometry (total volume, diameter stenosis, and area stenosis) and tissue composition (calcium, LRNC, and IPH) are measured reliably from clinical CTA images using a semiautomatic image analysis program. The minimum change in plaque volume detectable is ∼4% if the same observer makes both measurements and ∼10% for different observers. Small changes in plaque composition can also be detected reliably. This approach can facilitate longitudinal studies for identifying high-risk plaque features and for quantifying plaque progression or regression after treatment.

Preoperative factors associated with patient satisfaction 2 years after elective shoulder surgery.

Background Purpose: Patient satisfaction has become an increasingly important component of quality measures for both hospital reimbursement and quality assessment. Additionally, patient satisfaction influences patient behavior and patient follow-up. The purpose of this study was to identify preoperative factors associated with patient satisfaction 2 years after shoulder surgery. Methods: Electronic surveys were used to collect patient information including demographic, surgical, and social history, as well as outcome data. Satisfaction was measured 2 years after surgery using the Surgical Satisfaction Questionnaire. Results: Multivariable linear regression identified preoperative Patient-Reported Outcomes Measurement Information System Pain Interference, annual income, and American Society of Anesthesiologists score as independent predictors of lower patient satisfaction, while total shoulder arthroplasty was an independent predictor of greater patient satisfaction. The model accounted for 15% of the variance in satisfaction scores (R2 = 0.15). Conclusion: Patient satisfaction 2 years after shoulder surgery is associated with preoperative patient-reported outcome scores. Lower patient satisfaction is independently predicted by greater preoperative PROMIS PI, income less than $70,000, and ASA score >1, while higher patient satisfaction is predicted by total shoulder arthroplasty.

Preoperative characteristics predictive of PROMIS Pain Interference two years after shoulder surgery.

INTRODUCTION: The objective of this study was to identify preoperative characteristics associated with worse Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference (PI) two years after shoulder surgery. METHODS: This was a retrospective analysis of prospectively collected data on 293 patients who underwent elective shoulder surgery. Survey questionnaires were collected within one week of surgery and then two years postoperatively. Bivariate analysis was used to identify associations and multivariable analysis was used to control for confounding variables. RESULTS: Worse two-year PROMIS PI was significantly correlated with older age, higher BMI, greater comorbidities, more prior surgeries, and multiple socio-demographic factors. Less improvement in PROMIS PI was significantly correlated with greater comorbidities, more previous surgeries, unemployment, prior orthopaedic surgery on the operative joint, and a higher American Society of Anesthesiologists (ASA) score. Better scores on all preoperative patient-reported outcome measures correlated with better two-year PROMIS PI. Multivariable analysis demonstrated that worse two-year PROMIS PI was independently predicted by the following preoperative factors: Workers' Compensation claim, opioid use, worse whole body Numeric Pain Score, and worse PROMIS PI. Less improvement in two-year PROMIS PI was predicted by the same preoperative factors. CONCLUSION: Worse PROMIS PI after shoulder surgery was associated with older age, greater comorbidities, mental health impairment, and lower socioeconomic status. Preoperative predictors of worse pain interference two years after shoulder surgery included Workers' Compensation, opioid use, worse whole body pain, and worse PROMIS PI. LEVEL OF EVIDENCE: III.

Infrapopliteal Arterial Pseudoaneurysm Development Secondary to Blunt Trauma: Case Series and Literature Review.

OBJECTIVES: Infrapopliteal arterial pseudoaneurysms (IAP) following blunt trauma with associated orthopedic injuries are uncommon, often present in a delayed fashion, and encompass a diagnostic and therapeutic dilemma. Herein, we present a series of IAPs that were diagnosed following blunt trauma and their management. METHODS: Case series consisting of 3 patients and a review of the international literature. RESULTS: Our case series included 3 patients presenting with IAPs following blunt trauma with associated orthopedic injuries. They were all identified in a delayed manner (>3 weeks) after the orthopedic injuries were treated. All patients presented with pain and a pulsatile mass while one concurrently had neurologic deficits. The pseudoaneurysms were diagnosed by duplex ultrasound and confirmed by angiography to be originating from the tibioperoneal trunk, anterior tibial, and posterior tibial arteries respectively. Two patients were treated with surgical excision. Of these, one required an arterial bypass procedure while the other underwent direct ligation only. The third patient was treated by endovascular coiling. A literature review from 1950 to the present found 51 reported cases of IAP resulting from blunt trauma. Ninety percent of trauma-related infrapopliteal injuries occurred in men with a mean delay in diagnosis of 5.6 months (median 1.8 months) after injury. Since 1950, management has shifted from primarily ligation to incorporating minimally invasive endovascular techniques when appropriate. CONCLUSIONS: Infrapopliteal artery pseudoaneurysms are rare following blunt skeletal trauma. A delay in diagnosis often occurs and can result in major morbidity and extensive surgical intervention. We recommend a high index of suspicion and a thorough vascular examination in patients with lower extremity skeletal trauma to help identify and treat these injuries early and effectively.

Lost in translation? Microchimersim detection in experimental and clinical transplantation.

The importance of further elucidating the properties surrounding microchimerism in various experi- mental models and clinical transplantation are limited by current techniques and the sensitivity of available platforms. Development of reliable methods and use routine use of microchimerism detection in clinical practice could guide clinical decision making regarding rejection, stable function, and tolerance.