Large, Wide-Neck, Side-Wall Aneurysm Treatment in Canines Using NeuroCURE: A Novel Liquid Embolic.

BACKGROUND: Untreated intracranial aneurysms can rupture and result in high rates of morbidity and mortality. Although there are numerous approved endovascular aneurysm treatment devices, most require dual anti-platelet therapy, are minimally biocompatible, or are prone to recanalization. Neurovascular Controlled Uniform Rapid Embolic (NeuroCURE) is an innovative polymer gel material with long-term stability, biocompatibility, and hemocompatibility developed for the treatment of large, wide-neck aneurysms. METHODS: Sidewall aneurysms were surgically created in 10 canines and NeuroCURE was injected through a 0.025 microcatheter under a single balloon inflation period. Aneurysm treatment was angiographically assessed post-embolization and pre-term with Raymond-Roy occlusion classification and a qualitative flow grade scale. Aneurysm neck stability and biocompatibility was histologically assessed to grade platelet/fibrin thrombus, percent endothelialization, and neointimal formation. Aneurysm sac stability was assessed by NeuroCURE sac content, inflammation, and neo-angiogenesis scales. RESULTS: Explanted aneurysms exhibited a smooth surface at the aneurysm neck with nearly complete neointimal coverage at 3-months. By 6-months, neck endothelialization was 100% in all animals (average Raymond-Roy occlusion classification of 1.2), with no instances of aneurysm recanalization or parent vessel flow compromise. Biocompatibility assessments verified a lack of inflammatory response, neo-angiogenesis, and platelet/fibrin thrombus formation. CONCLUSION: The NeuroCURE material promotes progressive occlusion of wide-necked side wall aneurysms over time without the need for dual antiplatelet agents. NeuroCURE also promotes neointimal tissue infill without dependence on thrombus formation and thus resists aneurysm recanalization. NeuroCURE remains a compelling investigational device for the treatment of intracranial aneurysms.

A cost analysis of sorafenib for desmoid tumors.

INTRODUCTION: A recent randomized trial demonstrated that sorafenib improved progression free survival (PFS) in patients with desmoid tumors despite many patients experiencing stable disease or spontaneous regression without treatment. Utilizing these trial data, we performed a cost analysis of sorafenib efficacy through two years of treatment. METHODS: Current Medicare Part D rates for sorafenib were utilized (dose 400 mg/day, cost $309/day). Annual costs per progression and objective response were calculated. Radiologic progression and response were defined using RECIST criteria. Patients with disease progression were separately analyzed in two groups: both clinical and radiologic (CAR), and radiologic alone. RESULTS: 84 previously randomized patients were analyzed (placebo: 35, sorafenib: 49). At one year, sorafenib was associated with a 43% absolute risk reduction (ARR) of CAR progression and number-needed-to-treat (NNT) of 2.3 patients/year, costing $259,406. At two years, ARR was 48% and NNT of 2.1 patients/year, costing $473,697. When evaluating only patients with RECIST defined radiologic progression, sorafenib patients experienced ARR of 13.9% with NNT 7.2 and estimated costs of $812,052 at one year. Two-year ARR was 17.5% with NNT 5.7 and estimated costs $1,285,052. Sorafenib patients experienced improved RECIST partial response rates at 1 and 2 years of 14.7% and 14.3%, with NNT 6.8 and 6.9, and costs of $766,938 and $1,556,433; respectively. CONCLUSION: For the treatment of desmoid tumors, Sorafenib led to improved PFS, but at a significant cost per patient. Favorable RECIST outcomes were less likely and costlier. Patients should be informed of possible benefits of treatment versus potential financial burden.

Comprehensive quality initiative leads to immediate postoperative extubation following liver transplant.

BACKGROUND: Immediate postoperative extubation (IPE) can reduce perioperative complications and length of stay (LOS), however it is performed variably after liver transplant across institutions and has historically excluded high-risk recipients from consideration. In late 2012, we planned and implemented a single academic institution structured quality improvement (QI) initiative to standardize perioperative care of liver transplant recipients without exceptions. We hypothesized that such an approach would lead to a sustained increase in IPE after primary (PAC) and delayed abdominal closure (DAC). METHODS: We retrospectively studied 591 patients from 2013 to 2018 who underwent liver transplant after initiative implementation. We evaluated trends in incidence of IPE versus delayed extubation (DE), and reintubation, LOS, and mortality. RESULTS: Overall, 476/591 (80.5%) recipients underwent PAC (278 IPE, 198 DE) and 115/591 (19.5%) experienced DAC (39 IPE, 76 DE). When comparing data from 2013 to data from 2018, the incidence of IPE increased from 9/67 (13.4%) to 78/90 (86.7%) after PAC and from 1/12 (8.3%) to 16/23 (69.6%) after DAC. For the same years, the incidence of IPE after PAC for recipients with MELD scores ≥30 increased from 0/19 (0%) to 12/17 (70.6%), for recipients who underwent simultaneous liver-kidney transplant increased from 1/8 (12.5%) to 4/5 (80.0%), and for recipients who received massive transfusion (>10 units of packed red blood cells) increased from 0/17 (0%) to 10/13 (76.9%). Reintubation for respiratory considerations <48 h after IPE occurred in 3/278 (1.1%) after PAC and 1/39 (2.6%) after DAC. IPE was associated with decreased intensive care unit (HR of discharge: 1.92; 95% CI: 1.58, 2.33; P < 0.001) and hospital LOS (HR of discharge: 1.45; 95% CI: 1.20, 1.76; P < 0.001) but demonstrated no association with mortality. CONCLUSION: A structured QI initiative led to sustained high rates of IPE and reduced LOS in all liver transplant recipients, including those classified as high risk.

Prophylactic Recombinant Factor VIIa for Preventing Massive Transfusion During Orthotopic Liver Transplantation.

OBJECTIVES: RecombinanthumanactivatedfactorVIIahas been usedprophylactically to mitigate requirements for transfusion in liver transplant. We explored its effectiveness andrisks amonglivertransplantrecipients at high risk for massive transfusion. MATERIALS AND METHODS: We performed a retrospective study of recipients who underwent liver transplant from 2012 to 2015. Patients considered at risk for massive transfusion received up to two 20 µg/kg doses of recombinant human activated factor VIIa, with rescue use permitted for other patients. We used propensity matching to determine the average treatment effectson patients who received recombinant human activated factor VIIa prophylactically to prevent massive transfusion. We determined thromboembolic events from medical record review. RESULTS: Of 234 liver transplant recipients, 38 received prophylactic and 2 received rescue recombinant human activated factor VIIa. We used a prediction model to readily identify those who would receive prophylactic recombinant human activated factorVIIa (C statistic = 0.885; 95% CI, 0.835-0.935). Propensity matching achieved balance, particularly for massive transfusion. Twenty-three of 38 patients (60.5%) who received recombinant human activated factorVIIa and 47 of 76 matched controls (61.8%) experienced massive transfusion. The coefficient for the average treatment effect of prophylactic administration was - 0.013 (95% CI, -0.260 to 0.233; P = .92). The cohorts exhibited no difference in number ofthromboembolic events (P > .99), although fatal events occurred in 1 patient who had prophylactic and 1 patient who had rescue recombinant human activated factor VIIa. CONCLUSIONS: Prophylactic recombinanthumanactivated factor VIIa use in patients at elevated risk of massive transfusion did not affect incidence of massive transfusion and was not associated with an increase in thromboembolic events overall. The lack of clinical benefit and the potential for fatal throm-boembolic events observed with recombinant human activated factor VIIa precluded its prophylactic use in liver transplant recipients.

What is the optimal anesthetic monitoring regarding immediate and short-term outcomes after liver transplantation?-A systematic review of the literature and expert panel recommendations.

BACKGROUND: Liver transplant centers vary in approach to intraoperative vascular accesses, monitoring of cardiac function and temperature management. Evidence is limited regarding impact of selected modalities on postoperative outcomes. OBJECTIVES: To review the literature and provide expert panel recommendations on optimal intraoperative arterial blood pressure (BP), central venous pressure (CVP), and vascular accesses, monitoring of cardiac function and intraoperative temperature management regarding immediate and short-term outcomes after orthotopic liver transplant (OLT). METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Recommendations made for: (1) Vascular accesses, arterial BP and CVP monitoring, (2) cardiac function monitoring, and (3) Intraoperative temperature management (CRD42021239908). RESULTS: Of 2619 articles screened 16 were included. Studies were small, retrospective, and observational. Vascular access studies demonstrated low rates of insertion complications. TEE studies demonstrated low rates of esophageal hemorrhage. One study found lower hospital-LOS and 30-day mortality in patients monitored with both PAC and TEE. Other monitoring studies were heterogenous in design and outcomes. Temperature studies showed increased blood transfusion and ventilation times in hypothermic groups. CONCLUSIONS: Recommendations were made for; routine arterial and CVP monitoring as a minimum standard of practice, consideration of discrepancy between peripheral and central arterial BP in patients with hemodynamic instability and high vasopressor requirements, and routine use of high flow cannulae while monitoring for extravasation and hematoma formation. Availability and expertise in PAC and/or TEE monitoring is strongly recommended particularly in hemodynamic instability, portopulmonary HT and/or cardiac dysfunction. TEE use is recommended as an acceptable risk in patients with treated esophageal varices and is an effective diagnostic tool for emergency cardiovascular collapse. Maintenance of intraoperative normothermia is strongly recommended.

Application of nondestructive mechanical characterization testing for creating in vitro vessel models with material properties similar to human neurovasculature.

Vessel models are a first step in developing endovascular medical devices. However, these models, often made from glass or silicone, do not accurately represent the mechanical properties of human vascular tissue, limiting their use to basic training and proof-of-concept testing. This study outlines methods to quantify human vascular tissue mechanical properties and synthetic biomaterials for creating representative vessel models. Human vascular tissue was assessed and compared to silicone and new UV-cured polymers (VC-A30) using the following eight mechanical tests: compressive, shear, tensile dynamic elastic modulus, Poisson's ratio, hardness, radial force, compliance, and lubricity. Half of these testing methods were nondestructive, allowing for multiple mechanical and histological characterizations of the same human tissue sample. Histological evaluation of the cellular and extracellular matrix of the human vessels verified that the dynamic moduli and Poison's ratio tests were nondestructive. Fluid absorption by VC-A30 showed statistically significant softening of mechanical properties, stabilizing after 4 days in phosphate-buffered saline (PBS). Human vasculature exhibited notably similar results to VC-A30 in five of eight mechanical tests (≤30% difference) versus two of eight for standard silicone (≤38% difference). Results show that VC-A30 provides a new option for 3D-printing translucent in vitro vascular models with anatomically relevant mechanical properties. These new vessel analogs may simulate patient-specific vessel disease states, improve surgical training models, accelerate new endovascular device developments, and ultimately reduce the need for animal models.

Anti-Severe Acute Respiratory Syndrome Coronavirus 2 Hyperimmune Immunoglobulin Demonstrates Potent Neutralization and Antibody-Dependent Cellular Cytotoxicity and Phagocytosis Through N and S Proteins.

BACKGROUND: Although coronavirus disease 2019 (COVID-19) vaccinations have provided a significant reduction in infections, effective COVID-19 treatments remain an urgent need. METHODS: Functional characterization of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hyperimmune immunoglobulin (hIG) from human convalescent plasma was performed by different virus neutralization methodologies (plaque reduction, virus-induced cytotoxicity, median tissue culture infectious dose [TCID50] reduction, and immunofluorimetry) at different laboratories using geographically different SARS-CoV-2 isolates (USA [1], Italy [1], and Spain [2]; 2 containing the D614G mutation). Neutralization capacity against the original Wuhan SARS-CoV-2 strain and variants (D614G mutant, B.1.1.7, P.1, and B.1.351) was evaluated using a pseudovirus expressing the corresponding spike (S) protein. Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) was also evaluated. RESULTS: All SARS-CoV-2 isolates were potently neutralized by hIG as shown by all 4 methodologies. Wild-type SARS-CoV-2 and variants were effectively neutralized using the pseudovirus. The hIG (IgG type) induced ADCC and ADCP against SARS-CoV-2 N and S proteins but not E protein. Very low concentrations (25-100 µg IgG/mL) were required. A potent effect was triggered by antibodies in hIG solutions against the SARS-CoV-2 S and N proteins. CONCLUSIONS: Beyond neutralization, IgG Fc-dependent pathways may play a role in combatting SARS-CoV-2 infections using COVID-19 hIG. This could be especially relevant for the treatment of more neutralization-resistant SARS-CoV-2 variants.

Definitions of intracranial aneurysm size and morphology: A call for standardization.

BACKGROUND: Intracranial aneurysms (IAs) are classified based on size (maximal dome diameter) as well as additional parameters such as neck diameter and dome-to-neck ratio (DNR). The neurosurgical literature includes a wide variety of definitions for both IA size and neck classifications. Standardizing the definitions of IA size and wide-neck classifications would help eliminate inconsistencies and potential misunderstandings of aneurysm morphology and rupture risk. METHODS: We queried the MEDLINE (EBSCO) database using the terms "unruptured IA" and ("small" or "medium" or "large") and filtered based on publication date, language, and scholarly journals. The resulting articles and their references were further screened for eligibility. This identified 286 records, of which 104 were excluded, leaving 182 articles for analysis. The review found several different IA size classifications and neck classifications. RESULTS: A review of the existing literature describing size and neck classifications revealed 13 size classifications for small aneurysms, four classifications for medium aneurysms, 15 classifications for large aneurysms, and one classification for giant aneurysms. There were also seven different wide-neck classifications found. CONCLUSION: It is imperative that a standardization in classification be implemented to help interventionalists make the most informed decisions regarding emerging treatment options as new endovascular technologies and devices are emerging with indications based around these classifications. Based on the database findings, this article recommends standardized quantitative measurement ranges for IA size and neck classifications.

Application of a rabbit-elastase aneurysm model for preliminary histology assessment of the PPODA-QT liquid embolic.

BACKGROUND: PPODA-QT is a novel liquid embolic under development for the treatment of cerebral aneurysms. We sought to test the rabbit-elastase aneurysm model to evaluate the tissue response following PPODA-QT embolization. METHODS: Experimental elastase-induced aneurysms were created in fourteen New Zealand White Rabbits. Eight animals were used for aneurysm model and endovascular embolization technique development. Six PPODA-QT-treated animals were enrolled in the study. Control and aneurysm tissues were harvested at acute (n = 2), 1-month (n = 2), and 3-month (n = 2) timepoints and the tissues were prepared for histology assessment. RESULTS: All fourteen rabbit-elastase aneurysms resulted in small and medium aneurysm heights (<10 mm dome height) with highly variable neck morphologies, small midline dome diameters, and beyond-wide dome-to-neck (d: n) ratios. Histological evaluation of four aneurysms, treated with PPODA-QT, demonstrated reorganization of aneurysm wall elastin into a smooth muscle layer, and observed as early as the 1-month survival timepoint. At the aneurysm neck, a homogenous neointimal layer (200-300 µm) formed at the PPODA-QT interface, sealing off the parent vessel from the aneurysm dome. No adverse immune response was evident at 1- and 3-month survival timepoints. CONCLUSION: PPODA-QT successfully embolized the treated aneurysms. Following PPODA-QT embolization, neointimal tissue growth and remodeling were noted with minimal immunological response. The experimental aneurysms created in rabbits were uniformly small with inconsistent neck morphology. Further testing of PPODA-QT will be conducted in larger aneurysm models for device delivery optimization and aneurysm healing assessment before human clinical investigation.

The disclosure slide-Informative or obligatory, 5 years of SSO Cancer Symposium oral presentations.

BACKGROUND: Financial disclosure (FD) highlights potential conflicts of interest but is often overlooked at academic conferences. METHODS: Retrospective review of 2015-2019 Society of Surgical Oncology Cancer Symposium oral presentation slide and/or verbal FD frequency, duration, and content. RESULTS: Of 963 presentations, 331 (34%) omitted disclosure slide/verbalization. 575 (60%) included a slide, 551 (57%) gave verbal disclosure and 133 (14%) stated relevance. 164 presentations (17%) cited 1 + FD. 2019 had greater median FDs/talk than 2015-2018 (3.50 vs. 2.00; p = .010). Compared to 2015-2018, 2019 yielded shorter median slide display of all disclosures (2.00 s vs. 2.47 s; p = .006), median 1 + FD display (3.37 s vs. 4.81 s; p = .04) and median 1 + FD verbalization (2.81 s vs. 3.66 s; p = .54). 2019 all disclosure verbalization increased (1.97 s vs. 1.14 s; p < .001). Multivariable modeling showed longer display with 2015-2018 (+1.3 s, 95% confidence interval [CI] -0.06 to 2.5 s, p = .04), <4 authors (+3.2 s, 95% CI: 2.1-4.3 s; p < .001) and longer verbalization with 2019 (+0.8 s, 95% CI: 0.2-1.4 s; p = .01), relevance (+1.0 s, 95% CI: 0.4-1.6 s; p = .002), ≤ 4 authors (+0.8 s, 95% CI: 0.3-1.3 s, p < .001) and noncommercial FD (+3.8 s, 95% CI: 2.0-5.0 s; p < .001). The five most cited commercial entities were in 39% of talks. CONCLUSION: Presenters' FDs were brief or omitted. Despite FD increase, disclosure time decreased. Improved FD attention will highlight potential COIs.

Meta-Analysis on the Effect of Pasireotide for Prevention of Postoperative Pancreatic Fistula.

BACKGROUND: A randomized controlled trial of routine administration of pasireotide demonstrated decreased incidence of clinically significant postoperative pancreatic fistula (POPF). Recent studies have not replicated these results. A meta-analysis was performed to evaluate its efficacy in this setting. METHODS: Prospective trials utilizing pasireotide prophylactically after pancreatectomy were reviewed. The primary outcome was clinically significant POPF. Secondary outcomes included length of stay (LOS), readmission rates, and mortality. Study heterogeneity was assessed. RESULTS: Five studies totaling 1571 patients were identified. There was no difference in age, sex, or cancer rates. Pasireotide patients had smaller pancreatic ducts (P < .001) and softer glands (P = .04). For all pancreatectomies, there was no difference in POPF rates (odds ratio [OR] 0.84; 95% CI 0.60-1.16, P = .29). Patients undergoing distal pancreatectomy (OR 0.70; 95% CI 0.30-1.63, P = .41) had similar rates of POPF versus pancreaticoduodenectomy (PD) patients who experienced a lower incidence of POPF (OR 0.60; 95% CI 0.42-0.86, P = .006).Mortality rates and LOS were similar. Readmission rates were decreased with pasireotide (OR 0.61; 95% CI 0.44-0.85). CONCLUSIONS: Routine administration of pasireotide did not decrease POPF rates for all pancreatectomies, but was associated with lower rates for PD, and decreased readmission rates. Further prospective, randomized studies are warranted.

Validation of predictive models identifying patients at risk for massive transfusion during liver transplantation and their potential impact on blood bank resource utilization.

BACKGROUND: Intraoperative massive transfusion (MT) is common during liver transplantation (LT). A predictive model of MT has the potential to improve use of blood bank resources. STUDY DESIGN AND METHODS: Development and validation cohorts were identified among deceased-donor LT recipients from 2010 to 2016. A multivariable model of MT generated from the development cohort was validated with the validation cohort and refined using both cohorts. The combined cohort also validated the previously reported McCluskey risk index (McRI). A simple modified risk index (ModRI) was then created from the combined cohort. Finally, a method to translate model predictions to a population-specific blood allocation strategy was described and demonstrated for the study population. RESULTS: Of the 403 patients, 60 (29.6%) in the development and 51 (25.5%) in the validation cohort met the definition for MT. The ModRI, derived from variables incorporated into multivariable model, ranged from 0 to 5, where 1 point each was assigned for hemoglobin level of less than 10 g/dL, platelet count of less than 100 × 109 /dL, thromboelastography R interval of more than 6 minutes, simultaneous liver and kidney transplant and retransplantation, and a ModRI of more than 2 defined recipients at risk for MT. The multivariable model, McRI, and ModRI demonstrated good discrimination (c statistic [95% CI], 0.77 [0.70-0.84]; 0.69 [0.62-0.76]; and 0.72 [0.65-0.79], respectively, after correction for optimism). For blood allocation of 6 or 15 units of red blood cells (RBCs) based on risk of MT, the ModRI would prevent unnecessary crossmatching of 300 units of RBCs/100 transplants. CONCLUSIONS: Risk indices of MT in LT can be effective for risk stratification and reducing unnecessary blood bank resource utilization.

Meta-analysis on the Effect of Pasireotide for Prevention of Postoperative Pancreatic Fistula.

BACKGROUND: A randomized controlled trial (RCT) of routine administration of pasireotide demonstrated decreased incidence of clinically significant postoperative pancreatic fistula (POPF). Recent studies have not replicated these results. A meta-analysis was performed to evaluate its efficacy in this setting. METHODS: Prospective trials utilizing pasireotide prophylactically after pancreatectomy were reviewed. The primary outcome was clinically significant POPF. Secondary outcomes included length of stay (LOS), readmission rates, and mortality. Study heterogeneity was assessed. RESULTS: Five studies totaling 1571 patients were identified. There was no difference in age, sex, or cancer rates. Pasireotide patients had smaller pancreatic ducts (P ≤.001) and softer glands (P = .04). For all pancreatectomies, there was no difference in POPF rates (OR 0.84; 95% CI 0.60-1.16, P = .29). Patients undergoing distal pancreatectomy (OR 0.70; 95% CI 0.30-1.63, P = .41) had similar rates of POPF versus pancreaticoduodenectomy (PD) patients that experienced a lower incidence of POPF (OR 0.60; 95% CI 0.42-0.86, P = .006). Mortality rates and LOS were similar. Readmission rates were decreased with pasireotide (OR 0.61; 95% CI 0.44-0.85). CONCLUSIONS: Routine administration of pasireotide did not decrease POPF rates for all pancreatectomies, but was associated with lower rates for PD and decreased readmission rates. Further prospective, randomized studies are warranted.

Error analysis of multi-needle Langmuir probe measurement technique.

Multi-needle Langmuir probe is a fairly new instrument technique that has been flown on several recent sounding rockets and is slated to fly on a subset of QB50 CubeSat constellation. This paper takes a fundamental look into the data analysis procedures used for this instrument to derive absolute electron density. Our calculations suggest that while the technique remains promising, the current data analysis procedures could easily result in errors of 50% or more. We present a simple data analysis adjustment that can reduce errors by at least a factor of five in typical operation.

The MT-CO1 V83I Polymorphism is a Risk Factor for Primary Open-Angle Glaucoma in African American Men.

Purpose: We investigate the function of the V83I polymorphism (m.6150G>A, rs879053914) in the mitochondrial cytochrome c oxidase subunit 1 (MT-CO1) gene and its role in African American (AA) primary open-angle glaucoma (POAG). Methods: This study used Sanger sequencing (1339 cases, 850 controls), phenotypic characterization of Primary Open-Angle African American Glaucoma Genetics study (POAAGG) cases, a masked chart review of CO1 missense cases (V83I plus M117T, n = 29) versus wild type cases (n = 29), a yeast 2-hybrid (Y2H) cDNA library screen, and quantification of protein-protein interactions by Y2H and ELISA. Results: The association of V83I with POAG in AA was highly significant for men (odds ratio [OR] 6.5; 95% confidence interval [CI] 2.0-21.3, P = 0.0001), but not for women (OR 1.1; 95% CI, 0.62-2.00, P = 0.78). POAG cases having CO1 double missense mutation (V83I + M117T, L1c2 haplogroup) had a higher cup-to-disc ratio (0.77 vs. 0.71, P = 0.04) and significantly worse visual function (average pattern standard deviation, 6.5 vs. 4.3, P = 0.009; average mean deviation -10.4 vs. -4.5, P = 0.006) when compared to matched wild type cases (L1b haplogroup). Interaction of the V83I region of CO1 with amyloid beta peptide (Aß) was confirmed by ELISA assay, and this interaction was abrogated by V83I. A Y2H screen of an adult human brain cDNA library with the V83 region of CO1 as bait retrieved the UBQLN1 gene. Conclusions: The V83I polymorphism was associated strongly with POAG in AA men and disrupts Aß-binding to CO1. This region also interacts with a neuroprotective protein, UBQLN1.

Quantifying the mechanical and histological properties of thrombus analog made from human blood for the creation of synthetic thrombus for thrombectomy device testing.

BACKGROUND: Untreated ischemic stroke can lead to severe morbidity and death, and as such, there are numerous endovascular blood-clot removal (thrombectomy) devices approved for human use. Human thrombi types are highly variable and are typically classified in qualitative terms - 'soft/red,' 'hard/white,' or 'aged/calcified.' Quantifying human thrombus properties can accelerate the development of thrombus analogs for the study of thrombectomy outcomes, which are often inconsistent among treated patients. METHODS: 'Soft'human thrombi were created from blood samples ex vivo (ie, human blood clotted in sample vials) and tested for mechanical properties using a hybrid rheometer material testing system. Synthetic thrombus materials were also mechanically tested and compared with the 'soft' human blood clots. RESULTS: Mechanical testing quantified the shear modulus and dynamic (elastic) modulus of volunteer human thrombus samples. This data was used to formulate a synthetic blood clot made from a composite polymer hydrogel of polyacrylamide and alginate (PAAM-Alg). The PAAM-Alg interpenetrating network of covalently and ionically cross-linked polymers had tunable elastic and shear moduli properties and shape memory characteristics. CONCLUSIONS: Due to its adjustable properties, PAAM-Alg can be modified to mimic various thrombi classifications. Future studies will include obtaining and quantitatively classifying patient thrombectomy samples and altering the PAAM-Alg to mimic the results for use with in vitro thrombectomy studies.

The prognostic value of the furosemide stress test in predicting delayed graft function following deceased donor kidney transplantation.

OBJECTIVES AND METHODS: The Furosemide Stress Test (FST) is a novel dynamic assessment of tubular function that has been shown in preliminary studies to predict patients who will progress to advanced stage acute kidney injury, including those who receive renal replacement therapy (RRT). The aim of this study is to investigate if the urinary response to a single intraoperative dose of intravenous furosemide predicts delayed graft function (DGF) in patients undergoing deceased donor kidney transplant. RESULTS: On an adjusted multiple logistic regression, a single 100 mg dose of intraoperative furosemide after the anastomosis of the renal vessels (FST) predicted the need for RRT at 2 and 6 h post kidney transplantation (KT). Recipient urinary output was measured at 2 and 6 h post furosemide administration. In receiver-operating characteristic (ROC) analysis, the FST predicted DGF with an area-under-the curve of 0.85 at an optimal urinary output cut-off of <600 mls at 6 h with a sensitivity of and a specificity of 83% and 74%, respectively. CONCLUSIONS: The FST is a predictor of DGF post kidney transplant and has the potential to identify patients requiring RRT early after KT.

Predictive Modeling of Massive Transfusion Requirements During Liver Transplantation and Its Potential to Reduce Utilization of Blood Bank Resources.

BACKGROUND: Patients undergoing liver transplantation frequently but inconsistently require massive blood transfusion. The ability to predict massive transfusion (MT) could reduce the impact on blood bank resources through customization of the blood order schedule. Current predictive models of MT for blood product utilization during liver transplantation are not generally applicable to individual institutions owing to variability in patient population, intraoperative management, and definitions of MT. Moreover, existing models may be limited by not incorporating cirrhosis stage or thromboelastography (TEG) parameters. METHODS: This retrospective cohort study included all patients who underwent deceased-donor liver transplantation at the Johns Hopkins Hospital between 2010 and 2014. We defined MT as intraoperative transfusion of > 10 units of packed red blood cells (pRBCs) and developed a multivariable predictive model of MT that incorporated cirrhosis stage and TEG parameters. The accuracy of the model was assessed with the goodness-of-fit test, receiver operating characteristic analysis, and bootstrap resampling. The distribution of correct patient classification was then determined as we varied the model threshold for classifying MT. Finally, the potential impact of these predictions on blood bank resources was examined. RESULTS: Two hundred three patients were included in the study. Sixty (29.6%) patients met the definition for MT and received a median (interquartile range) of 19.0 (14.0-27.0) pRBC units intraoperatively compared with 4.0 units (1.0-6.0) for those who did not satisfy the criterion for MT. The multivariable model for predicting MT included Model for End-stage Liver Disease score, whether simultaneous liver and kidney transplant was performed, cirrhosis stage, hemoglobin concentration, platelet concentration, and TEG R interval and angle. This model demonstrated good calibration (Hosmer-Lemeshow goodness-of-fit test P = .45) and good discrimination (c statistic: 0.835; 95% confidence interval, 0.781-0.888). A probability cutoff threshold of 0.25 was found to misclassify only 4 of 100 patients as unlikely to experience MT, with the majority such misclassifications within 4 units of the working definition for MT. For this threshold, a preoperative blood ordering schedule that allocated 6 units of pRBCs for those unlikely to experience MT and 15 for those who were likely to experience MT would prevent unnecessary crossmatching of 338 units/100 transplants. CONCLUSIONS: When clinical and laboratory parameters are included, a model predicting intraoperative MT in patients undergoing liver transplantation is sufficiently accurate that its predictions could guide the blood order schedule for individual patients based on institutional data, thereby reducing the impact on blood bank resources. Ongoing evaluation of model accuracy and transfusion practices is required to ensure continuing performance of the predictive model.