Three-Year Outcomes of the Abre Venous Self-Expanding Stent System in Patients with Symptomatic Iliofemoral Venous Outflow Obstruction.

PURPOSE: To report 36-month outcomes and subgroup analysis of the ABRE study evaluating the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction disease. METHODS: The ABRE study was a prospective, multicenter, nonrandomized study that enrolled and implanted Abre venous stents in 200 participants (mean age 51.5 years [SD ± 15.9], 66.5% women) with symptomatic iliofemoral venous outflow obstruction at 24 global sites. Outcomes assessed through 36 months included patency, major adverse events, stent migration, stent fracture, and quality-of-life changes. Adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. RESULTS: Primary, primary-assisted, and secondary patency through 36 months by Kaplan-Meier estimates were 81.6%, 84.8%, and 86.3%, respectively. The cumulative incidence of major adverse events through 36 months was 10.2%, mainly driven by 12 thrombosis events. Subgroup analyses demonstrated a primary patency of 76.5% in the acute deep vein thrombosis group, 70.4% in the postthrombotic syndrome group, and 97.1% in the nonthrombotic iliac vein lesion group through 36 months. The overall mean lesion length was 112.4 mm (SD ± 66.1). There were no stent fractures or migrations in this study. Quality of life and venous functional assessments demonstrated significant improvements from baseline to 36 months across all patient subsets. CONCLUSIONS: Results from the ABRE study demonstrated sustained patency with a good safety profile after implantation of a dedicated venous stent in patients with symptomatic iliofemoral venous outflow obstruction disease.

Design of a treatment satisfaction measure for patients undergoing varicose vein treatment: Venous Treatment Satisfaction Questionnaire (VenousTSQ).

BACKGROUND: Established condition-specific patient-reported outcome measures for varicose veins are limited to the measurement of health status and function. A treatment satisfaction measure is needed to understand patient satisfaction with different treatment options. The aim of this study was to design a Venous Treatment Satisfaction Questionnaire (VenousTSQ) that would be ready for large-scale data collection and psychometric evaluation. METHODS: Relevant items were selected from the -TSQ Item Library and new items were designed where necessary. A draft VenousTSQ was prepared using the existing AneurysmTSQ as a template. Fifteen interviews were conducted from 4 days to 16 months after the procedure. The interviews were designed to elicit important sources of satisfaction or dissatisfaction before completion of draft questionnaires. The VenousTSQ drafts were modified between sets of interviews until no further changes were required. RESULTS: The final VenousTSQ consists of two questionnaires: VenousTSQ early (VenousTSQe) and VenousTSQ status (VenousTSQs). Items that need be asked only once are in the VenousTSQe, whereas those that can usefully be asked more than once are in the VenousTSQs. Of the 16 unique items forming the VenousTSQ, 12 were from the -TSQ Item Library. Only 1 of these 12 required significant modification. CONCLUSIONS: The VenousTSQ represents a condition-specific psychological outcome measure for varicose veins, enabling patient satisfaction or dissatisfaction with such treatments to be measured. Large-scale data collection is under way to establish optimal scoring, quantitative validity, and reliability of the VenousTSQ.

Research Priorities in Pelvic Venous Disorders in Women: Recommendations from a Multidisciplinary Research Consensus Panel.

Pelvic venous disorders (PeVDs) in women can present with chronic pelvic pain, lower-extremity and vulvar varicosities, lower-extremity swelling and pain, and left-flank pain and hematuria. Multiple evidence gaps exist related to PeVDs with the consequence that nonvascular specialists rarely consider the diagnosis. Recognizing this, the Society of Interventional Radiology Foundation funded a Research Consensus Panel to prioritize a research agenda to address these gaps. This paper presents the proceedings and recommendations from that Panel.

Mutations in the Transmembrane Domain and Cytoplasmic Tail of Hendra Virus Fusion Protein Disrupt Virus-Like-Particle Assembly.

Hendra virus (HeV) is a zoonotic paramyxovirus that causes deadly illness in horses and humans. An intriguing feature of HeV is the utilization of endosomal protease for activation of the viral fusion protein (F). Here we investigated how endosomal F trafficking affects HeV assembly. We found that the HeV matrix (M) and F proteins each induced particle release when they were expressed alone but that their coexpression led to coordinated assembly of virus-like particles (VLPs) that were morphologically and physically distinct from M-only or F-only VLPs. Mutations to the F protein transmembrane domain or cytoplasmic tail that disrupted endocytic trafficking led to failure of F to function with M for VLP assembly. Wild-type F functioned normally for VLP assembly even when its cleavage was prevented with a cathepsin inhibitor, indicating that it is endocytic F trafficking that is important for VLP assembly, not proteolytic F cleavage. Under specific conditions of reduced M expression, we found that M could no longer induce significant VLP release but retained the ability to be incorporated as a passenger into F-driven VLPs, provided that the F protein was competent for endocytic trafficking. The F and M proteins were both found to traffic through Rab11-positive recycling endosomes (REs), suggesting a model in which F and M trafficking pathways converge at REs, enabling these proteins to preassemble before arriving at plasma membrane budding sites.IMPORTANCE Hendra virus and Nipah virus are zoonotic paramyxoviruses that cause lethal infections in humans. Unlike that for most paramyxoviruses, activation of the henipavirus fusion protein occurs in recycling endosomal compartments. In this study, we demonstrate that the unique endocytic trafficking pathway of Hendra virus F protein is required for proper viral assembly and particle release. These results advance our basic understanding of the henipavirus assembly process and provide a novel model for the interplay between glycoprotein trafficking and paramyxovirus assembly.

Cyanoacrylate closure of incompetent great, small and accessory saphenous veins without the use of post-procedure compression: Initial outcomes of a post-market evaluation of the VenaSeal System (the WAVES Study).

Purpose Cyanoacrylate closure of the great saphenous vein with the VenaSeal™ Closure System is a relatively new modality. Studies have been limited to moderate-sized great saphenous veins and some have mandated postoperative compression stockings. We report the results of a prospective study of cyanoacrylate closure for the treatment of great saphenous vein, small saphenous veins, and/or accessory saphenous veins up to 20 mm in diameter. Methods Fifty subjects with symptomatic great saphenous vein, small saphenous veins, and/or accessory saphenous veins incompetence were each treated at a single session. Compression stockings were not used post-procedure. Subjects returned to clinic at week 1 and again at one month. Post-procedure evaluations were performed at seven days and one month and included numerical pain rating score, revised venous clinical severity score, the Aberdeen Varicose Vein Questionnaire score, and time to return to work and normal activities. Duplex ultrasound was performed at each visit. Findings Procedural pain was mild (numerical pain rating scale 2.2 ± 1.8). All treated veins (48 great saphenous vein, 14 accessory saphenous veins, and 8 small saphenous veins) had complete closure by duplex ultrasound at seven days and one month. Mean time to return to work and normal activities was 0.2 ± 1.1 and 2.4 ± 4.1 days, respectively. The revised venous clinical severity score was improved to 1.8 ± 1.4 ( p < .001) and Aberdeen Varicose Vein Questionnaire score to 8.9 ± 6.6 ( p < .001) at one month. Phlebitis in the treatment area or side branches occurred in 10 subjects (20%) and completely resolved in all but one subject (2%) by one month; 98% of subjects were "completely" or "somewhat" satisfied, and 2% "unsatisfied" with the procedure at one month, despite the protocol disallowance of concomitant side branch treatment. Conclusions Cyanoacrylate closure is safe and effective for the treatment of one or more incompetent saphenous or accessory saphenous veins. Closure rates were high even in the absence of the use of compression stockings or side branch treatment. Time back to work or normal activities was short and improvements in venous severity scores and QOL were significant, comparing favorably with alternative treatment methods.

Randomized trial comparing cyanoacrylate embolization and radiofrequency ablation for incompetent great saphenous veins (VeClose).

BACKGROUND: Whereas thermal ablation of incompetent saphenous veins is highly effective, all heat-based ablation techniques require the use of perivenous subfascial tumescent anesthesia, involving multiple needle punctures along the course of the target vein. Preliminary evidence suggests that cyanoacrylate embolization (CAE) may be effective in the treatment of incompetent great saphenous veins (GSVs). We report herein early results of a randomized trial of CAE vs radiofrequency ablation (RFA) for the treatment of symptomatic incompetent GSVs. METHODS: Two hundred twenty-two subjects with symptomatic GSV incompetence were randomly assigned to receive either CAE (n = 108) with the VenaSeal Sapheon Closure System (Sapheon, Inc, Morrisville, NC) or RFA (n = 114) with the ClosureFast system (Covidien, Mansfield, Mass). After discharge, subjects returned to the clinic on day 3 and again at months 1 and 3. The study's primary end point was closure of the target vein at month 3 as assessed by duplex ultrasound and adjudicated by an independent vascular ultrasound core laboratory. Statistical testing focused on showing noninferiority with a 10% delta conditionally followed by superiority testing. No adjunctive procedures were allowed until after the month 3 visit, and missing month 3 data were imputed by various methods. Secondary end points included patient-reported pain during vein treatment and extent of ecchymosis at day 3. Additional assessments included general and disease-specific quality of life surveys and adverse event rates. RESULTS: All subjects received the assigned intervention. By use of the predictive method for imputing missing data, 3-month closure rates were 99% for CAE and 96% for RFA. All primary end point analyses, which used various methods to account for the missing data rate (14%), showed evidence to support the study's noninferiority hypothesis (all P < .01); some of these analyses supported a trend toward superiority (P = .07 in the predictive model). Pain experienced during the procedure was mild and similar between treatment groups (2.2 and 2.4 for CAE and RFA, respectively, on a 10-point scale; P = .11). At day 3, less ecchymosis in the treated region was present after CAE compared with RFA (P < .01). Other adverse events occurred at a similar rate between groups and were generally mild and well tolerated. CONCLUSIONS: CAE was proven to be noninferior to RFA for the treatment of incompetent GSVs at month 3 after the procedure. Both treatment methods showed good safety profiles. CAE does not require tumescent anesthesia and is associated with less postprocedure ecchymosis.

Trimeric transmembrane domain interactions in paramyxovirus fusion proteins: roles in protein folding, stability, and function.

Paramyxovirus fusion (F) proteins promote membrane fusion between the viral envelope and host cell membranes, a critical early step in viral infection. Although mutational analyses have indicated that transmembrane (TM) domain residues can affect folding or function of viral fusion proteins, direct analysis of TM-TM interactions has proved challenging. To directly assess TM interactions, the oligomeric state of purified chimeric proteins containing the Staphylococcal nuclease (SN) protein linked to the TM segments from three paramyxovirus F proteins was analyzed by sedimentation equilibrium analysis in detergent and buffer conditions that allowed density matching. A monomer-trimer equilibrium best fit was found for all three SN-TM constructs tested, and similar fits were obtained with peptides corresponding to just the TM region of two different paramyxovirus F proteins. These findings demonstrate for the first time that class I viral fusion protein TM domains can self-associate as trimeric complexes in the absence of the rest of the protein. Glycine residues have been implicated in TM helix interactions, so the effect of mutations at Hendra F Gly-508 was assessed in the context of the whole F protein. Mutations G508I or G508L resulted in decreased cell surface expression of the fusogenic form, consistent with decreased stability of the prefusion form of the protein. Sedimentation equilibrium analysis of TM domains containing these mutations gave higher relative association constants, suggesting altered TM-TM interactions. Overall, these results suggest that trimeric TM interactions are important driving forces for protein folding, stability and membrane fusion promotion.

Effect of junctional reflux on the venous clinical severity score in patients with insufficiency of the great saphenous vein (JURY study).

OBJECTIVE: Effective treatment options are available for chronic venous insufficiency associated with superficial venous reflux. Although many patients with C2 and C3 disease based on the CEAP (Clinical-Etiological-Anatomical-Pathophysiological) classification have combined great saphenous vein (GSV) and saphenofemoral junction (SFJ) reflux, some may not have concomitant SFJ reflux. Several payors have determined that symptom severity in patients without SFJ reflux does not warrant treatment. In patients planned for venous ablation, we tested whether Venous Clinical Severity Scores (VCSS) are equivalent in those with GSV reflux alone compared with those with both GSV and SFJ reflux. METHODS: This cross-sectional study was conducted at 10 centers. Inclusion criteria were: candidate for endovenous ablation as determined by treating physician; 18 to 80 years of age; GSV reflux with or without SFJ reflux on ultrasound; and C2 or C3 disease. Exclusion criteria were prior deep vein thrombosis; prior vein ablation on the index limb; ilio-caval obstruction; and renal, hepatic, or heart failure requiring prior hospitalization. An a priori sample size was calculated. We used multiple linear regression (adjusted for patient characteristics) to compare differences in VCSS scores of the two groups at baseline, and to test whether scores were equivalent using a priori equivalence boundaries of +1 and -1. In secondary analyses, we tested differences in VCSS scores in patients with C2 and C3 disease separately. RESULTS: A total of 352 patients were enrolled; 64.2% (n = 226) had SFJ reflux, and 35.8% (n = 126) did not. The two groups did not differ by major clinical characteristics. The mean age of the cohort was 53.9 ± 14.3 years; women comprised 74.2%; White patients 85.8%; and body mass index was 27.8 ± 6.1 kg/m2. The VCSS scores in patients with and without SFJ reflux were found to be equivalent; SFJ reflux was not a significant predictor of VCSS score; and mean VCSS scores did not differ significantly (6.4 vs 6.6, respectively, P = .40). In secondary subset analyses, VCSS scores were equivalent between C2 patients with and without SFJ reflux, and VCSS scores of C3 patients with SFJ reflux were lower than those without SFJ reflux. CONCLUSIONS: Symptom severity is equivalent in patients with GSV reflux with or without SFJ reflux. The absence of SFJ reflux alone should not determine the treatment paradigm in patients with symptomatic chronic venous insufficiency. Patients with GSV reflux who meet clinical criteria for treatment should have equivalent treatment regardless of whether or not they have SFJ reflux.

Consensus Statement on the Management of Nonthrombotic Iliac Vein Lesions From the VIVA Foundation, the American Venous Forum, and the American Vein and Lymphatic Society.

A nonthrombotic iliac vein lesion is defined as the extrinsic compression of the iliac vein. Symptoms of lower extremity chronic venous insufficiency or pelvic venous disease can develop secondary to nonthrombotic iliac vein lesion. Anatomic compression has been observed in both symptomatic and asymptomatic patients. Causative factors that lead to symptomatic manifestations remain unclear. To provide guidance for providers treating patients with nonthrombotic iliac vein lesion, the VIVA Foundation convened a multidisciplinary group of leaders in venous disease management with representatives from the American Venous Forum and the American Vein and Lymphatic Society. Consensus statements regarding nonthrombotic iliac vein lesions were drafted by the participants to address patient selection, imaging for diagnosis, technical considerations for stent placement, postprocedure management, and future research/educational needs.

Shaping the future US bioeconomy through safety, security, sustainability, and social responsibility.

Biomanufacturing practitioners and researchers describe the norms that should govern the growing, global field, to include safety, security, sustainability, and social responsibility. These '4S Principles' should be broadly adopted so that the future of the field may provide the greatest benefits to society.

Guidelines for management of actual or suspected inadvertent intra-arterial injection of sclerosants.

BACKGROUND: Inadvertent intra-arterial injection of sclerosants is an uncommon adverse event of both ultrasound-guided and direct vision sclerotherapy. This complication can result in significant tissue or limb loss and significant long-term morbidity. OBJECTIVES: To provide recommendations for diagnosis and immediate management of an unintentional intra-arterial injection of sclerosing agents. METHODS: An international and multidisciplinary expert panel representing the endorsing societies and relevant specialities reviewed the published biomedical, scientific and legal literature and developed the consensus-based recommendations. RESULTS: Actual and suspected cases of an intra-arterial sclerosant injection should be immediately transferred to a facility with a vascular/interventional unit. Digital Subtraction Angiography (DSA) is the key investigation to confirm the diagnosis and help select the appropriate intra-arterial therapy for tissue ischaemia. Emergency endovascular intervention will be required to manage the risk of major limb ischaemia. This includes intra-arterial administration of vasodilators to reduce vasospasm, and anticoagulants and thrombolytic agents to mitigate thrombosis. Mechanical thrombectomy, other endovascular interventions and even open surgery may be required. Lumbar sympathetic block may be considered but has a high risk of bleeding. Systemic anti-inflammatory agents, anticoagulants, and platelet inhibitors and modifiers would complement the intra-arterial endovascular procedures. For risk of minor ischaemia, systemic oral anti-inflammatory agents, anticoagulants, vasodilators and antiplatelet treatments are recommended. CONCLUSION: Inadvertent intra-arterial injection is an adverse event of both ultrasound-guided and direct vision sclerotherapy. Medical practitioners performing sclerotherapy must ensure completion of a course of formal training (specialty or subspecialty training, or equivalent recognition) in the management of venous and lymphatic disorders (phlebology), and be personally proficient in the use of duplex ultrasound in vascular (both arterial and venous) applications, to diagnose and provide image guidance to venous procedure. Expertise in diagnosis and immediate management of an intra-arterial injection is essential for all practitioners performing sclerotherapy.

Novel FOXF1 mutations in sporadic and familial cases of alveolar capillary dysplasia with misaligned pulmonary veins imply a role for its DNA binding domain.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung defined by a constellation of characteristic histopathological features. Nonpulmonary anomalies involving organs of gastrointestinal, cardiovascular, and genitourinary systems have been identified in approximately 80% of patients with ACD/MPV. We have collected DNA and pathological samples from more than 90 infants with ACD/MPV and their family members. Since the publication of our initial report of four point mutations and 10 deletions, we have identified an additional 38 novel nonsynonymous mutations of FOXF1 (nine nonsense, seven frameshift, one inframe deletion, 20 missense, and one no stop). This report represents an up to date list of all known FOXF1 mutations to the best of our knowledge. Majority of the cases are sporadic. We report four familial cases of which three show maternal inheritance, consistent with paternal imprinting of the gene. Twenty five mutations (60%) are located within the putative DNA-binding domain, indicating its plausible role in FOXF1 function. Five mutations map to the second exon. We identified two additional genic and eight genomic deletions upstream to FOXF1. These results corroborate and extend our previous observations and further establish involvement of FOXF1 in ACD/MPV and lung organogenesis.

Fake-news-free evidence-based communication for proper vein-lymphatic disease management.

Published scientific evidence demonstrate the current spread of healthcare misinformation in the most popular social networks and unofficial communication channels. Up to 40% of the medical websites were identified reporting inappropriate information, moreover being shared more than 450,000 times in a 5-year-time frame. The phenomenon is particularly spread in infective diseases medicine, oncology and cardiovascular medicine. The present document is the result of a scientific and educational endeavor by a worldwide group of top experts who selected and analyzed the major issues and related evidence-based facts on vein and lymphatic management. A section of this work is entirely dedicated to the patients and therefore written in layman terms, with the aim of improving public vein-lymphatic awareness. The part dedicated to the medical professionals includes a revision of the current literature, summing up the statements that are fully evidence-based in venous and lymphatic disease management, and suggesting future lines of research to fulfill the still unmet needs. The document has been written following an intense digital interaction among dedicated working groups, leading to an institutional project presentation during the Universal Expo in Dubai, in the occasion of the v-WINter 2022 meeting.

Great saphenous vein diameter does not correlate with worsening quality of life scores in patients with great saphenous vein incompetence.

OBJECTIVE: Previous studies have correlated increasing great saphenous vein (GSV) diameter with increasing CEAP clinical classification. Some insurance carriers are currently using specific GSV diameters to determine coverage for treatment of axial venous insufficiency. The aim of this study was to investigate the correlation of patient quality of life (QOL) measures with GSV diameters in varicose vein patients with GSV reflux. METHODS: Data were collected from the records of 91 patients prospectively enrolled in two varicose vein trials. The patients had symptomatic varicose veins with saphenofemoral junction and proximal GSV reflux. Maximum GSV diameter was measured on duplex ultrasound imaging, with the patient standing, within 5 cm of the saphenofemoral junction. Chronic Venous Insufficiency Questionnaire 2 (CIVIQ-2; Servier, Neuilly-sur-Seine, France), Venous Insufficiency Epidemiological and Economic Study (VEINES) Symptom (Sym) and QOL assessments, and the Venous Clinical Severity Score (VCSS) assessment were completed before treatment of GSV insufficiency. Demographic information, patient weight, height, and body mass index were collected. Correlations between pairs of data were done using Pearson product-moment and Spearman correlation coefficients. RESULTS: The 91 study patients (19 men, 72 women) were a mean age of 45 years (range, 18-65 years). The mean GSV diameter was 6.7 mm (range, 2.2-14.1 mm). The mean VCSS score was 7.8 (range, 3-12). There was a weak correlation between increasing GSV diameter and VCSS (r=0.23; P=.03) and no correlation between GSV diameter and the CIVIQ-2 score (r=0.01), VEINES-QOL (r=-0.07), and VEINES-Sym (r=-0.1). CONCLUSIONS: GSV diameter is a poor surrogate marker for assessing the effect of varicose veins on a patient's QOL; thus, using GSV diameter as a sole criterion for determining medical necessity for the treatment of GSV reflux is inappropriate. Further correlations between QOL measures and duplex-derived objective findings are warranted.

Human tool-making capacities reflect increased information-processing capacities: continuity resides in the eyes of the beholder.

Chimpanzee/human technological differences are vast, reflect multiple interacting behavioral processes, and may result from the increased information-processing and hierarchical mental constructional capacities of the human brain. Therefore, advanced social, technical, and communicative capacities probably evolved together in concert with increasing brain size. Interpretations of these evolutionary and species differences as continuities or discontinuities reflect differing scientific perspectives.

Pivotal Study Evaluating the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction.

BACKGROUND: Iliofemoral venous obstruction is recognized with increasing frequency as the underlying cause of lower extremity symptoms including edema, pain, skin changes, and, in advanced cases, ulceration. This study sought to evaluate the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction. METHODS: The ABRE Study (A Multi-Center, Non-Randomized Study to Evaluate the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction) is a single-arm, multicenter, prospective study that included 200 subjects from 24 global sites. The primary end points were 12-month primary patency and major adverse events within 30 days. Secondary end points included lesion and procedure success, primary-assisted and secondary patency, major adverse events, stent migration, stent fracture, and quality of life changes. End point-related adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. RESULTS: Venous obstruction cause was classified as acute deep vein thrombosis (16.5%, 33/200), post-thrombotic syndrome (47.5%, 95/200), or nonthrombotic iliac vein lesion (36.0%, 72/200). The common iliac and external iliac veins were stented in 96.0% (192/200), 80.5% (161/200) of subjects, respectively. Stent implant into the common femoral vein was required in 44.0% (88/200). Primary patency at 12 months was 88.0% (162/184). Four (2.0%) major adverse events occurred within 30 days. Twelve-month primary-assisted and secondary patency were 91.8% (169/184) and 92.9% (171/184), respectively. No stent fractures or migrations were reported. Mean target limb Villalta score decreased from 11.2±5.6 at baseline to 4.1±4.8 at 12 months, and the mean target limb revised Venous Clinical Severity Score decreased from 8.8±4.7 at baseline to 4.3±3.6 at 12 months. Clinically meaningful improvements in quality of life and venous functional assessment scores from baseline were demonstrated through 12 months in all measures. CONCLUSIONS: Symptomatic iliofemoral venous obstruction can be successfully treated with an Abre venous stent. Study outcomes demonstrated a high patency rate with a good safety profile. Patients demonstrated a significant reduction in clinical symptoms and improvement in quality of life that was maintained through 12-month follow-up. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03038438.

Exposure Route Influences Disease Severity in the COVID-19 Cynomolgus Macaque Model.

The emergence of SARS-CoV-2 and the subsequent pandemic has highlighted the need for animal models that faithfully replicate the salient features of COVID-19 disease in humans. These models are necessary for the rapid selection, testing, and evaluation of potential medical countermeasures. Here, we performed a direct comparison of two distinct routes of SARS-CoV-2 exposure-combined intratracheal/intranasal and small particle aerosol-in two nonhuman primate species, rhesus and cynomolgus macaques. While all four experimental groups displayed very few outward clinical signs, evidence of mild to moderate respiratory disease was present on radiographs and at necropsy. Cynomolgus macaques exposed via the aerosol route also developed the most consistent fever responses and had the most severe respiratory disease and pathology. This study demonstrates that while all four models produced suitable representations of mild COVID-like illness, aerosol exposure of cynomolgus macaques to SARS-CoV-2 produced the most severe disease, which may provide additional clinical endpoints for evaluating therapeutics and vaccines.

Clinical significance of cerebrovascular gas emboli during polidocanol endovenous ultra-low nitrogen microfoam ablation and correlation with magnetic resonance imaging in patients with right-to-left shunt.

BACKGROUND: Foam generated by manual agitation of liquid sclerosant with air or gas is routinely utilized to treat refluxing veins. Although generally well tolerated, serious neurological events have been reported. The composition and properties of the foam, including bubble size and gaseous components, may contribute to the potential for microcirculatory obstruction and cerebral ischemia. We tested an ultra-low nitrogen polidocanol endovenous microfoam with controlled bubble size and density and hypothesized that patients at risk due to the presence of middle cerebral artery (MCA) bubble emboli during microfoam injection would not demonstrate evidence of clinical or subclinical cerebral infarction. METHODS: Patients with great saphenous vein incompetence were treated with ultra-low nitrogen (≤ 0.8%) polidocanol endovenous microfoam injected under ultrasound guidance. Patients with right-to-left shunt were included to evaluate the safety of cerebral arterial bubbles. All patients with MCA emboli detected by transcranial Doppler during endovenous microfoam ablation received intensive surveillance for microinfarction, including brain magnetic resonance imaging and measurement of cardiac troponin-I. RESULTS: MCA bubble emboli were detected in 60 of 82 treated patients; 22 patients had no detectable emboli. Among patients with MCA bubbles detected, 49 (82%) had ≤ 15 bubbles. No patients developed magnetic resonance imaging abnormalities, neurological signs, or elevated cardiac troponin. CONCLUSIONS: Patients treated with foamed liquid sclerosants are commonly exposed to cerebrovascular gas bubbles. In this series of 60 high-risk patients with MCA bubble emboli during or after treatment with ultra-low nitrogen polidocanol endovenous microfoam, there was no evidence of cerebral or cardiac microinfarction. The results of this study cannot be generalized to foams compounded using bedside methodologies, since the composition of these foams is substantially different.