Safety and efficacy of percutaneous image-guided ablation for soft tissue sarcoma metastases to the liver

PURPOSE

To evaluate outcomes following percutaneous image-guided ablation of soft tissue sarcoma metastases to the liver.

MATERIALS AND METHODS

A single-institution retrospective analysis of patients with a diagnosis of metastatic soft tissue sarcoma who underwent percutaneous image-guided ablation of hepatic metastases between January 2011 and December 2021 was performed. Patients with less than 60 days of follow-up after ablation were excluded. The primary outcome was local tumor progression-free survival (LPFS). Secondary outcomes included overall survival, liver-specific progression-free survival. and chemotherapy-free survival.

RESULTS

Fifty-five patients who underwent percutaneous ablation for 84 metastatic liver lesions were included. The most common histopathological subtypes were leiomyosarcoma (23/55), followed by gastrointestinal stromal tumor (22/55). The median treated liver lesions was 2 (range, 1-8), whereas the median size of metastases were 1.8 cm (0.3-8.7 cm). Complete response at 2 months was achieved in 90.5% of the treated lesions. LPFS was 83% at 1 year and 80% at 2 years. Liver-specific progression-free survival was 66% at 1 year and 40% at 2 years. The overall survival at 1 and 2 years was 98% and 94%. The chemotherapy-free holiday from the start of ablation was 71.2% at 12 months. The complication rate was 3.6% (2/55); one of the complications was Common Terminology Criteria for Adverse Events grade 3 or higher. LPFS subgroup analysis for leiomyosarcoma versus gastrointestinal stromal tumor suggests histology-agnostic outcomes (2 years, 89% vs 82%, p = .35).

CONCLUSION

Percutaneous image-guided liver ablation of soft tissue sarcoma metastases is safe and efficacious.

Current Perspectives and Progress in Preoperative Portal Vein Embolization with Stem Cell Augmentation (PVESA)

Portal vein embolization with stem cell augmentation (PVESA) is an emerging approach for enhancing the growth of the liver segment that will remain after surgery (i.e., future liver remnant, FLR) in patients with liver cancer. Conventional portal vein embolization (PVE) aims to induce preoperative FLR growth, but it has a risk of failure in patients with underlying liver dysfunction and comorbid illnesses. PVESA combines PVE with stem cell therapy to potentially improve FLR size and function more effectively and efficiently. Various types of stem cells can help improve liver growth by secreting paracrine signals for hepatocyte growth or by transforming into hepatocytes. Mesenchymal stem cells (MSCs), unrestricted somatic stem cells, and small hepatocyte-like progenitor cells have been used to augment liver growth in preclinical animal models, while clinical studies have demonstrated the benefit of CD133 + bone marrow-derived MSCs and hematopoietic stem cells. These investigations have shown that PVESA is generally safe and enhances liver growth after PVE. However, optimizing the selection, collection, and application of stem cells remains crucial to maximize benefits and minimize risks. Additionally, advanced stem cell technologies, such as priming, genetic modification, and extracellular vesicle-based therapy, that could further enhance efficacy outcomes should be evaluated. Despite its potential, PVESA requires more investigations, particularly mechanistic studies that involve orthotopic animal models of liver cancer with concomitant liver injury as well as larger human trials.

Phase 1b study of intraperitoneal ipilimumab and nivolumab in patients with recurrent gynecologic malignancies with peritoneal carcinomatosis

BACKGROUND

Intravenous immune checkpoint blockade (ICB) has shown poor response rates in recurrent gynecologic malignancies. Intraperitoneal (i.p.) ICB may result in enhanced T cell activation and anti-tumor immunity.

METHODS

In this phase 1b study, registered at Clinical.

TRIALS

gov (NCT03508570), initial cohorts received i.p. nivolumab monotherapy, and subsequent cohorts received combination i.p. nivolumab every 2 weeks and i.p. ipilimumab every 6 weeks, guided by a Bayesian design. The primary objective was determination of the recommended phase 2 dose (RP2D) of the combination. Secondary outcomes included toxicity, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

FINDINGS

The trial enrolled 23 patients: 18 with ovarian cancer, 2 with uterine cancer, and 3 with cervical cancer. Study evaluable patients (n = 16) received a median of 2 prior lines of therapy (range: 1-8). Partial response was observed in 2 patients (12.5%; 1 ovarian, 1 uterine), and complete response was observed in 1 patient (6.3%) with cervical cancer, for an ORR of 18.8% (95% confidence interval: 4.0%-45.6%). The median duration of response was 14.8 months (range: 4.1-20.8), with one complete response ongoing. Median PFS and OS were 2.7 months and not reached, respectively. Grade 3 or higher immune-related adverse events occurred in 2 (8.7%) patients.

CONCLUSIONS

i.p. administration of dual ICB is safe and demonstrated durable responses in a subset of patients with advanced gynecologic malignancy. The RP2D is 3 mg/kg i.p. nivolumab every 2 weeks plus 1 mg/kg ipilimumab every 6 weeks.

FUNDING

This work was funded by Bristol Myers Squibb (CA209-9C7), an MD Anderson Cancer Center Support Grant (CA016672), the Ovarian Cancer Moon Shots Program, the Emerson Collective Fund, and a T32 training grant (CA101642).

Intraprocedural Versus Initial Follow-up Minimal Ablative Margin Assessment After Colorectal Liver Metastasis Thermal Ablation: Which One Better Predicts Local Outcomes?

OBJECTIVES

The aim of this study was to investigate the prognostic value of 3-dimensional minimal ablative margin (MAM) quantified by intraprocedural versus initial follow-up computed tomography (CT) in predicting local tumor progression (LTP) after colorectal liver metastasis (CLM) thermal ablation.

MATERIALS AND METHODS

This single-institution, patient-clustered, tumor-based retrospective study included patients undergoing microwave and radiofrequency ablation between 2016 and 2021. Patients without intraprocedural and initial follow-up contrast-enhanced CT, residual tumors, or with follow-up less than 1 year without LTP were excluded. Minimal ablative margin was quantified by a biomechanical deformable image registration method with segmentations of CLMs on intraprocedural preablation CT and ablation zones on intraprocedural postablation and initial follow-up CT. Prognostic value of MAM to predict LTP was tested using area under the curve and competing-risk regression model.

RESULTS

A total of 68 patients (mean age ± standard deviation, 57 ± 12 years; 43 men) with 133 CLMs were included. During a median follow-up of 30.3 months, LTP rate was 17% (22/133). The median volume of ablation zone was 27 mL and 16 mL segmented on intraprocedural and initial follow-up CT, respectively ( P < 0.001), with corresponding median MAM of 4.7 mm and 0 mm, respectively ( P < 0.001). The area under the curve was higher for MAM quantified on intraprocedural CT (0.89; 95% confidence interval [CI], 0.83-0.94) compared with initial follow-up CT (0.66; 95% CI, 0.54-0.76) in predicting 1-year LTP ( P < 0.001). An MAM of 0 mm on intraprocedural CT was an independent predictor of LTP with a subdistribution hazards ratio of 11.9 (95% CI, 4.9-28.9; P < 0.001), compared with 2.4 (95% CI, 0.9-6.0; P = 0.07) on initial follow-up CT.

CONCLUSIONS

Ablative margin quantified on intraprocedural CT significantly outperformed initial follow-up CT in predicting LTP and should be used for ablation endpoint assessment.

[Multicenter retrospect analysis of early clinical features and analysis of risk factors on prognosis of elderly patients with severe burns]

Objective: To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis. Methods: This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results: Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions: The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.

Liver volumetry and liver-regenerative interventions: history, rationale, and emerging tools

BACKGROUND

Postoperative hepatic insufficiency (PHI) is the most feared complication after hepatectomy. Volume of the future liver remnant (FLR) is one objectively measurable indicator to identify patients at risk of PHI. In this review, we summarized the development and rationale for the use of liver volumetry and liver-regenerative interventions and highlighted emerging tools that could yield new advancements in liver volumetry.

METHODS

A review of MEDLINE/PubMed, Embase, and Cochrane Library databases was conducted to identify literature related to liver volumetry. The references of relevant articles were reviewed to identify additional publications.

RESULTS

Liver volumetry based on radiologic imaging was developed in the 1980s to identify patients at risk of PHI and later used in the 1990s to evaluate grafts for living donor living transplantation. The field evolved in the 2000s by the introduction of standardized FLR based on the hepatic metabolic demands and in the 2010s by the introduction of the degree of hypertrophy and kinetic growth rate as measures of the FLR regenerative and functional capacity. Several liver-regenerative interventions, most notably portal vein embolization, are used to increase resectability and reduce the risk of PHI. In parallel with the increase in automation and machine assistance to physicians, many semi- and fully automated tools are being developed to facilitate liver volumetry.

CONCLUSION

Liver volumetry is the most reliable tool to detect patients at risk of PHI. Advances in imaging analysis technologies, newly developed functional measures, and liver-regenerative interventions have been improving our ability to perform safe hepatectomy.

Image-Guided Deployment and Monitoring of a Novel Tungsten Nanoparticle-Infused Radiopaque Absorbable Inferior Vena Cava Filter in a Swine Model

PURPOSE

To improve radiopacity of radiolucent absorbable poly-p-dioxanone (PPDO) inferior vena cava filters (IVCFs) and demostrate their effectiveness in clot-trapping ability.

MATERIALS AND METHODS

Tungsten nanoparticles (WNPs) were incorporated along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of WNPs. The physicochemical and in vitro and in vivo imaging properties of PPDO IVCFs with WNPs with single-polymer PHB (W-P) were compared with those of WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB).

RESULTS

In vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physicomechanical properties of the PPDO sutures. W-P- and W-PB-coated IVCFs were deployed successfully into the inferior vena cava of pig models with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at Week 3 for both filters.

CONCLUSIONS

The results highlight the utility of nanoparticles (NPs) and polymers for enhancing radiopacity of medical devices. Different methods of incorporating NPs and polymers can still be explored to improve the effectiveness, safety, and quality of absorbable IVCFs.

Unequivocal Identification of Spin-Triplet and Spin-Singlet Superconductors with Upper Critical Field and Flux Quantization

Spin-triplet superconductors play central roles in Majorana physics and quantum computing but are difficult to identify. We show the methods of kink-point upper critical field and flux quantization in superconducting rings can unequivocally identify spin-singlet, spin-triplet in centrosymmetric superconductors, and singlet-triplet admixture in noncentrosymmetric superconductors, as realized in γ-BiPd, β-Bi_{2}Pd, and α-BiPd, respectively. Our findings are essential for identifying triplet superconductors and exploring their quantum properties.

Percutaneous nephrostomy catheter-related infections in patients with gynaecological cancers: a multidisciplinary algorithmic approach

BACKGROUND

Percutaneous nephrostomy catheters (PCNs) are commonly utilized in patients with gynaecological cancers due to intrinsic or extrinsic urinary obstruction. Unfortunately, these foreign medical devices may be associated with several infectious complications, including: pyelonephritis, renal abscess, and bacteraemia, which may lead to further delay of life-saving cancer therapy.

AIM

To evaluate the performance of our multidisciplinary algorithm for diagnosis and treatment of PCN-related infections (PCNIs) and identify risk factors for recurrent urinary device-related infections.

METHODS

Patients with gynaecological cancers having PCNIs were prospectively evaluated at our institution from July 2019 to September 2021. All patients were managed by our standardized algorithm and followed-up until reinfection or routine PCN exchange.

FINDINGS

Of 100 consecutive patients with PCNIs, 74 had adequate follow-up, and were analysed in three groups according to clinical outcome: reinfection with the same organism (26%), reinfection with a different organism (23%), and no reinfection (51%). Their median age was 54 years, and the most common cancers were cervical (65%), and ovarian (19%) with 53% being metastatic. The most frequently recovered micro-organisms were Pseudomonas (32%), Enterococcus (27%), and Escherichia (24%) species. The main risk factors for recurrent PCNI with the same organism were pelvic radiation therapy (P=0.032), pelvic fistulas (P=0.014), and a PCNI with the same pathogen within the previous year (P = 0.012).

CONCLUSIONS

Our algorithm has allowed for accurate diagnosis, staging, and treatment of and identification of several key risk factors for recurrent PCNIs. These results may lead to further preventive measures for these infections.

Bioresorbable Mesenchymal Stem Cell-Loaded Electrospun Polymeric Scaffold Inhibits Neointimal Hyperplasia Following Arteriovenous Fistula Formation in a Rat Model of Chronic Kidney Disease

Bioresorbable perivascular scaffolds loaded with antiproliferative agents have been shown to enhance arteriovenous fistula (AVF) maturation by inhibiting neointimal hyperplasia (NIH). These scaffolds, which can mimic the three-dimensional architecture of the vascular extracellular matrix, also have an untapped potential for the local delivery of cell therapies against NIH. Hence, an electrospun perivascular scaffold from polycaprolactone (PCL) to support mesenchymal stem cell (MSC) attachment and gradual elution at the AVF's outflow vein is fabricated. Chronic kidney disease (CKD) in Sprague-Dawley rats is induced by performing 5/6th nephrectomy, then AVFs for scaffold application are created. The following groups of CKD rats are compared: no perivascular scaffold (i.e., control), PCL alone, and PCL+MSC scaffold. PCL and PCL+MSC significantly improve ultrasonographic (i.e., luminal diameter, wall-to-lumen ratio, and flow rate) and histologic (i.e., neointima-to-lumen ratio, neointima-to-media ratio) parameters compared to control, with PCL+MSC demonstrating further improvement in these parameters compared to PCL alone. Moreover, only PCL+MSC significantly reduces 18 F-fluorodeoxyglucose uptake on positron emission tomography. These findings suggest that adding MSCs promotes greater luminal expansion and potentially reduces the inflammatory process underlying NIH. The results demonstrate the utility of mechanical support loaded with MSCs at the outflow vein immediately after AVF formation to support maturation by minimizing NIH.

Gold Nanoparticles for Monitoring of Mesenchymal Stem-Cell-Loaded Bioresorbable Polymeric Wraps for Arteriovenous Fistula Maturation

Mesenchymal stem cell (MSC)-seeded polymeric perivascular wraps have been shown to enhance arteriovenous fistula (AVF) maturation. However, the wraps' radiolucency makes their placement and integrity difficult to monitor. Through electrospinning, we infused gold nanoparticles (AuNPs) into polycaprolactone (PCL) wraps to improve their radiopacity and tested whether infusion affects the previously reported beneficial effects of the wraps on the AVF's outflow vein. Sprague Dawley rat MSCs were seeded on the surface of the wraps. We then compared the effects of five AVF treatments-no perivascular wrap (i.e., control), PCL wrap, PCL + MSC wrap, PCL-Au wrap, and PCL-Au + MSC wrap-on AVF maturation in a Sprague Dawley rat model of chronic kidney disease (n = 3 per group). Via micro-CT, AuNP-infused wraps demonstrated a significantly higher radiopacity compared to that of the wraps without AuNPs. Wraps with and without AuNPs equally reduced vascular stenoses, as seen via ultrasonography and histomorphometry. In the immunofluorescence analysis, representative MSC-seeded wraps demonstrated reduced neointimal staining for markers of infiltration with smooth muscle cells (α-SMA), inflammatory cells (CD45), and fibroblasts (vimentin) compared to that of the control and wraps without MSCs. In conclusion, AuNP infusion allows in vivo monitoring via micro-CT of MSC-seeded polymeric wraps over time, without compromising the benefits of the wrap for AVF maturation.

[Research advances on the role of complement system activation in post-burn immunity]

Immune activation is one of the major factors of secondary injury post burn, and is the main organismal response in the anti-infection process. As an important part of the innate immune response, the complement system is able to induce the activation of immune cells after burns, promote inflammation and mediate the breakdown of the immune barrier, and even engage in complex cross-linking with the coagulation cascade. This article reviews the role of complement system activation in post-burn immunity and its possibility of clinical translation from the perspectives of innate immunity, acquired immunity, and cross-linking of the complement system with the coagulation cascade.

MGF360-12L of ASFV-SY18 is an immune-evasion protein that inhibits host type I IFN, NF-κB, and JAK/STAT pathways

African swine fever virus (ASFV) causes feverous and hemorrhagic disease of domestic pigs and European wild boars with high mortality, yet no commercial vaccine is currently available. Several ASFV strains with natural deletion or gene-targeted knockout of multiple MGF360 and MGF505 genes are attenuated in vitro and in vivo, and can offer full protection against homologous challenge. However, the mechanisms underlying the protection are not fully understood. This study aims to investigate the effects of MGF360-12L of ASFV-SY18 on the cGAS-STING signaling pathway and explore the potential mechanisms. We identified that ASFV-SY18 MGF360-12L could inhibit cGAS-STING, TBK1, or IRF3-5D-stimulated IFN-β expression and ISRE activation. Specifically, MGF360-12L inhibits both the activation of PRD(III-I) in a dose-dependent manner, and suppresses the exogenous expression of TBK1 and IRF3-5D. MGF360-12L could block NF-κB activation induced by overexpression of cGAS-STING, TBK1, IKKβ. Downstream of the IFN-β signaling, MGF360-12L blocks the ISRE promoter activation by reducing total protein level of IRF9. Moreover, MGF360-12L protein can inhibit IFN-β-mediated antiviral effects. In conclusion, our findings suggest that MGF360-12L is a multifunctional immune-evasion protein that inhibits both the expression and effect of IFN-β, which could partially explain the attenuation of relevant gene-deleted ASFV strains, and shed light on the development of efficient ASFV live attenuated vaccines in the future.

Image-guided deployment and monitoring of a novel tungsten nanoparticleâ€"infused radiopaque absorbable inferior vena cava filter in pigs

The use of absorbable inferior vena cava filters (IVCFs) constructed with poly-p-dioxanone (PPDO) eliminates risks and complications associated with the use of retrievable metallic filters. Radiopacity of radiolucent PPDO IVCFs can be improved with the incorporation of nanoparticles (NPs) made of high-atomic number materials such as gold and bismuth. In this study, we focused on incorporating tungsten NPs (WNPs), along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of the WNPs. We compared the imaging properties of WNPs with single-polymer PHB (W-P) and WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). Our in vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physico-mechanical properties of the PPDO sutures. We observed a more sustained release of WNPs from W-PB-coated sutures than W-P-coated sutures. We successfully deployed W-P- and W-PB-coated IVCFs into the inferior vena cava of pig models, with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at week 3 for both filters. Results of this study highlight the utility of NPs and polymers for enhancing radiopacity of medical devices; however, different methods of incorporating NPs and polymers can still be explored to improve the efficacy, safety, and quality of absorbable IVCFs.

Rosuvastatin-Eluting Gold Nanoparticle-Loaded Perivascular Implantable Wrap for Enhanced Arteriovenous Fistula Maturation in a Murine Model

Background

Arteriovenous fistulas (AVFs) are a vital intervention for patients requiring hemodialysis, but they also contribute to overall mortality due to access malfunction. The most common cause of both AVF non-maturation and secondary failure is neointimal hyperplasia (NIH). Absorbable polycaprolactone (PCL) perivascular wraps can address these complications by incorporating drugs to attenuate NIH, such as rosuvastatin (ROSU), and metallic nanoparticles for visualization and device monitoring.

Objectives

This study aimed to assess the impacts of gold nanoparticle (AuNP) and ROSU-loaded perivascular wraps on vasculature NIH and AVF maturation and patency in a chronic kidney disease rat model.

Methods

Electrospun wraps containing combinations of PCL, AuNP, and ROSU were monitored for in vitro drug elution, nanoparticle release, tensile strength, and cell viability. Perivascular wraps were implanted in chronic kidney disease rats for in vivo ultrasound (US) and micro-computed tomography (mCT) imaging. AVF specimens were collected for histological analyses.

Results

No difference in cell line viability was observed in ROSU-containing grafts. In vitro release studies of ROSU and AuNPs correlated with decreasing radiopacity over time on in vivo mCT analysis. The mCT study also demonstrated increased radiopacity in AuNP-loaded wraps compared with PCL and control. The addition of ROSU demonstrated decreased US and histologic measurements of NIH.

Conclusions

The reduced NIH seen with ROSU-loading of perivascular wraps suggests a synergistic effect between mechanical support and anti-hyperplasia medication. Furthermore, the addition of AuNPs increased wrap radiopacity. Together, our results show that radiopaque, AuNP-, and ROSU-loaded PCL grafts induce AVF maturation and suppress NIH while facilitating optimal implanted device visualization.

Gold Nanoparticles for Monitoring of Mesenchymal Stem Cell-Loaded Bioresorbable Polymeric Wraps for Arteriovenous Fistulas

Background

To address high rates of arteriovenous fistula (AVF) failure, a mesenchymal stem cell (MSC)-seeded polymeric perivascular wrap has been developed to reduce neointimal hyperplasia (NIH) and enhance AVF maturation in a rat model. However, the wrap's radiolucency makes its placement and integrity difficult to monitor.

Purpose

In this study, we infused gold nanoparticles (AuNPs) into the polymeric perivascular wrap to improve its radiopacity and tested the effect of infusion on the previously reported beneficial effects of the polymeric wrap on the AVF outflow vein.

Materials and Methods

We fabricated a polymeric perivascular wrap made of polycaprolactone (PCL) infused with AuNPs via electrospinning. Sprague-Dawley rat mesenchymal stem cells (MSCs) were seeded on the surface of the wraps. We then compared the effect of five AVF treatments-no perivascular wrap (i.e., control), PCL wrap, PCL+MSC wrap, PCL-Au wrap, and PCL-Au+MSC wrap-on AVF maturation in a Sprague-Dawley rat model of chronic kidney disease (n=3 per group). Statistical significance was defined as p<.05, and one-way analysis of variance was performed using GraphPad Prism software.

Results

On micro-CT, AuNP-infused wraps demonstrated significantly higher radiopacity compared to wraps without AuNPs. On ultrasonography, wraps with and without AuNPs equally reduced the wall-to-lumen ratio of the outflow vein, a marker of vascular stenosis. On histomorphometric analysis, wraps with and without AuNPs equally reduced the neointima-to- lumen ratio of the outflow vein, a measure of NIH. On immunofluorescence analysis, representative MSC-seeded wraps demonstrated reduced neointimal staining for markers of smooth muscle cells (α-SMA), inflammatory cells (CD45), and fibroblasts (vimentin) infiltration when compared to control and wraps without MSCs.

Conclusion

Gold nanoparticle infusion allows the in vivo monitoring via micro-CT of a mesenchymal stem cell-seeded polymeric wrap over time without compromising the benefits of the wrap on arteriovenous fistula maturation.

Summary Statement

Gold nanoparticle infusion enables in vivo monitoring via micro-CT of the placement and integrity over time of mesenchymal stem cell-seeded polymeric wrap supporting arteriovenous fistula maturation.

Key Results

Gold nanoparticle (AuNP)-infused perivascular wraps demonstrated higher radiopacity on micro-CT compared with wraps without AuNPs after 8 weeks.AuNP-infused perivascular wraps equally improved the wall-to-lumen ratio of the outflow vein (a marker of vascular stenosis) when compared with wraps without AuNPs, as seen on US.AuNP-infused perivascular wraps equally reduced the neointima-to-lumen ratio of the outflow vein (a measure of neointimal hyperplasia) when compared with wraps without AuNPs, as seen on histomorphometry.

Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction Technique for 3D MR Imaging in the Inpatient and Emergency Department Settings

BACKGROUND AND PURPOSE

A scout accelerated motion estimation and reduction (SAMER) framework has been developed for efficient retrospective motion correction. The goal of this study was to perform an initial evaluation of SAMER in a series of clinical brain MR imaging examinations.

MATERIALS AND METHODS

Ninety-seven patients who underwent MR imaging in the inpatient and emergency department settings were included in the study. SAMER motion correction was retrospectively applied to an accelerated T1-weighted MPRAGE sequence that was included in brain MR imaging examinations performed with and without contrast. Two blinded neuroradiologists graded images with and without SAMER motion correction on a 5-tier motion severity scale (none = 1, minimal = 2, mild = 3, moderate = 4, severe = 5).

RESULTS

The median SAMER reconstruction time was 1 minute 47 seconds. SAMER motion correction significantly improved overall motion grades across all examinations (P < .005). Motion artifacts were reduced in 28% of cases, unchanged in 64% of cases, and increased in 8% of cases. SAMER improved motion grades in 100% of moderate motion cases and 75% of severe motion cases. Sixty-nine percent of nondiagnostic motion cases (grades 4 and 5) were considered diagnostic after SAMER motion correction. For cases with minimal or no motion, SAMER had negligible impact on the overall motion grade. For cases with mild, moderate, and severe motion, SAMER improved the motion grade by an average of 0.3 (SD, 0.5), 1.1 (SD, 0.3), and 1.1 (SD, 0.8) grades, respectively.

CONCLUSIONS

SAMER improved the diagnostic image quality of clinical brain MR imaging examinations with motion artifacts. The improvement was most pronounced for cases with moderate or severe motion.

A novel method for predicting hepatocellular carcinoma response to chemoembolization using an intraprocedural CT hepatic arteriography-based enhancement mapping: a proof-of-concept analysis

BACKGROUND

To evaluate the feasibility of a novel approach for predicting hepatocellular carcinoma (HCC) response to drug-eluting beads transarterial chemoembolization (DEB-TACE) using computed tomography hepatic arteriography enhancement mapping (CTHA-EM) method.

METHODS

This three-institution retrospective study included 29 patients with 46 HCCs treated with DEB-TACE between 2017 and 2020. Pre- and posttreatment CTHA-EM images were generated using a prototype deformable registration and subtraction software. Relative tumor enhancement (T_Post/pre-RE) defined as the ratio of tumor enhancement to normal liver tissue was calculated to categorize tumor response as residual (T_Post-RE > 1) versus non-residual (T_Post-RE ≤ 1) enhancement, which was blinded compared to the response assessment on first follow-up imaging using modified RECIST criteria. Additionally, for tumors with residual enhancement, CTHA-EM was evaluated to identify its potential feeding arteries.

RESULTS

CTHA-EM showed residual enhancement in 18/46 (39.1%) and non-residual enhancement in 28/46 (60.9%) HCCs, with significant differences on T_Post-RE (3.05 ± 2.4 versus 0.48 ± 0.23, respectively; p < 0.001). The first follow-up imaging showed non-complete response (partial response or stable disease) in 19/46 (41.3%) and complete response in 27/46 (58.7%) HCCs. CTHA-EM had a response prediction sensitivity of 94.7% (95% CI, 74.0-99.9) and specificity of 100% (95% CI, 87.2-100). Feeding arteries to the residual enhancement areas were demonstrated in all 18 HCCs (20 arteries where DEB-TACE was delivered, 2 newly developed collaterals following DEB-TACE).

CONCLUSION

CTHA-EM method was highly accurate in predicting initial HCC response to DEB-TACE and identifying feeding arteries to the areas of residual arterial enhancement.

[Plasmids carried by carbapenems-resistant Klebsiella pneumoniae in burn patients and its correlation with strain transmission]

Objective: To explore the carrier status of carbapenems-resistant Klebsiella pneumoniae (CRKP) plasmids in burn patients and analyze the correlation of these plasmids with the transmission of CRKP. Methods: A retrospective observational study was conducted. A total of 26 CRKP strains, which were isolated from the clinic-related samples of 22 burn patients (with 20 males and 2 females, aged (42±16) years) admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January to December 2017, were collected and individually numbered. The plasmids of the strains were extracted by alkali lysis. After determination of the plasmid concentration by a nucleic acid concentration detector, the agarose gel electrophoresis was used to visualize the bands, and rough plasmids typing was performed. The plasmid of the smallest numbered CRKP in each plasmid type was transformed into competent Escherichia coli (E. coli) strain Top10 (hereinafter referred to as TOP10 strain). The growth of each transformed strains and a Top10 strain cultivated in ampicillin containing Luria-Bertani (LB) agar medium overnight was observed, and the proportion of successful transformation was calculated. The plasmids from the smallest numbered plasmid carrying CRKP strain of successfully transformed Top10 strains (hereinafter referred to as the smallest successfully transformed strain) and correspondingly numbered CRKP were extracted, and then, the agarose gel electrophoresis was used to visualize the bands. Aforementioned successfully transformed strains and a TOP10 strain were used for the antimicrobial susceptibility testing with 17 antibiotics commonly used in clinic. The plasmid from the smallest successfully transformed strain was sequenced using the next-generation sequencing technology. Bioinformatics analyses such as protein-coding gene prediction and protein sequence alignment were performed successively. The sequence was subsequently named pKP03-NDM1 according to the carrying of drug resistance gene. According to the whole genome sequence of the plasmid carried by the smallest successfully transformed strain, the polymerase chain reaction, agarose gel electrophoresis, and gene sequencing were used to detect the New Delhi metallo-beta lactamase-1 (blaNDM-1) of plasmids in the remaining 25 strains of CRKP. The ST typing in multilocus sequence typing of 26 strains of CRKP was analyzed based on the literature. Results: Plasmids were successfully extracted from 26 CRKP, with mass concentrations ranging from 19.3 to 189.8 ng/μL. Each of the 26 CRKP carrying plasmids showed at least one band longer than 2 500 bp in the agarose gel electrophoresis, which were roughly divided into 6 patterns of A, B, C, D, E, and F. After overnight cultivation, no growth of strains was observed in LB agar medium containing ampicillin inoculated with the TOP10 strain or TOP10 strains transformed by the plasmid of CRKP patterning A, B, D, or E. In contrast, TOP10 strains transformed by the pattern C plasmid from NO.3 CRKP and the pattern F plasmid from NO.15 CRKP resulted in numerous colony growths, and those transformed strains were named as TOP10-pKP03 and TOP10-pKP15, respectively. The proportion of successful transformation was 1/3. The plasmid carried by TOP10-pKP03 showed a single band in the agarose gel electrophoresis, which was the same size as the largest band of the plasmid from NO.3 CRKP. The TOP10 strain was sensitive to the 17 antibiotics commonly used in clinic. TOP10-pKP03 and TOP10-pKP15 were resistant to penicillins, cephalosporins, and carbapenems but remained sensitive to monocyclic β-lactam, aminoglycosides, quinolones and tigecycline. The full length of the plasmid carried by TOP10-pKP03 was 41 190 bp. In addition to blaNDM-1, this plasmid carried bleMBL, T4SS, bleomycin resistance gene, conjugation transfer elements, and relaxase, etc. The plasmid showed 99% nucleotide identity similarity and the same length to the plasmid pJN24NDM1 extracted from an E. coli isolate JN24. Totally 16 (61.5%) CRKP were confirmed to carrying blaNDM-1 gene, among the ST typing of the 16 strains, 11 strains were ST11, while ST215, ST260, ST395, ST2230, and new ST had 1 strain each. Among the ST typing of 10 blaNDM-1-negative CRKP, 8 strains were ST11, while ST395 and ST2230 had 1 strain each. Conclusions: A blaNDM-1 gene carrying plasmid pKP03-NDM1 was extracted and sequenced from CRKP isolated from burn patients, with a high plasmid carrying rate. Meanwhile, this plasmid may mediate inter-CRKP and CRKP-E. coli horizontal transfer of blaNDM-1, leading to transmission of antimicrobial resistance.

2030. Risk Factors for Recurrent Percutaneous Nephrostomy Tube Infections in Patients with Gynecological Malignancies

Background

Percutaneous nephrostomy tube infections (PCNIs) are complex, affect quality of life, necessitate implant exchanges, and increase health care costs. Here, we analyzed risk factors for recurrent PCNIs in patients treated with our standardized institutional algorithm.

Methods

At our institution, we prospectively evaluated consecutive patients with gynecological malignancies who developed PCNIs between July 2019 to September 2021. All patients were treated using our institutional algorithm for PCNI, which consists of obtaining blood cultures plus urine analyses and cultures from each percutaneous nephrostomy tube (PCN); utilizing ultrasound or abdominal pelvic computed tomography scans to rule out obstructive hydronephrosis, pyelonephritis, or renal abscess; exchanging the PCN once patients are receiving concordant antimicrobial therapy; and having patients complete an adequate course of targeted antimicrobials. Thereafter, patients were followed up until reinfection, routine PCN exchange at 3 months, being lost to follow-up, or death.

Results

We treated 100 patients. Their median age was 54 years; 53% were White. The most common malignancies were cervical (61%), ovarian (23%), and endometrial (13%), with 60% being metastatic. To analyze the risk factors for developing a recurrent PCNI, patients were placed in 3 different groups: those reinfected with the same organism (19%), reinfected with a different organism (17%), and not reinfected (64%). Overall, there were no differences among the patient groups regarding demographics, comorbidities, clinical presentation, infection timing, PCN exchange (Table 1) or microorganisms encountered (Table 2). However, patients with prior radiation therapy or pelvic fistulas (urinary-vaginal-rectal or their permutations) had higher rates for developing a recurrent PCNIs with the same organism (P&lt; .002).

Conclusion

Patients with prior radiation therapy and underlying pelvic fistulas have an increased risk for reinfection with the same pathogen. Therefore, further studies should be performed to mitigate this increased risk of recurrent infections with more frequent PCN exchanges or, more invasive procedure such as ureteral embolization, sclerosis, or ligation to dissociate the upper and lower urinary tracts.

Disclosures

All Authors: No reported disclosures.

Localized Perivascular Therapeutic Approaches to Inhibit Venous Neointimal Hyperplasia in Arteriovenous Fistula Access for Hemodialysis Use

An arteriovenous fistula (AVF) is the preferred vascular access for chronic hemodialysis, but high failure rates restrict its use. Optimizing patients' perioperative status and the surgical technique, among other methods for preventing primary AVF failure, continue to fall short in lowering failure rates in clinical practice. One of the predominant causes of AVF failure is neointimal hyperplasia (NIH), a process that results from the synergistic effects of inflammation, hypoxia, and hemodynamic shear stress on vascular tissue. Although several systemic therapies have aimed at suppressing NIH, none has shown a clear benefit towards this goal. Localized therapeutic approaches may improve rates of AVF maturation by providing direct structural and functional support to the maturating fistula, as well as by delivering higher doses of pharmacologic agents while avoiding the adverse effects associated with systemic administration of therapeutic agents. Novel materials-such as polymeric scaffolds and nanoparticles-have enabled the development of different perivascular therapies, such as supportive mechanical devices, targeted drug delivery, and cell-based therapeutics. In this review, we summarize various perivascular therapeutic approaches, available data on their effectiveness, and the outlook for localized therapies targeting NIH in the setting of AVF for hemodialysis use. Highlights: Most systemic therapies do not improve AVF patency outcomes; therefore, localized therapeutic approaches may be beneficial. Locally delivered drugs and medical devices may improve AVF patency outcomes by providing biological and mechanical support. Cell-based therapies have shown promise in suppressing NIH by delivering a more extensive array of bioactive substances in response to the biochemical changes in the AVF microenvironment.

[Correlation of periodontitis and oculopathy]

With the development of researches on the relationship between periodontal health and general health, more and more evidences showed that periodontitis was closely related to oculopathy, while the mechanisms were not very clear at present. This article will focus on the influences of periodontitis on the occurrence and development of various oculopathy such as diabetic retinopathy and senile macular degeneration, and discuss the possible mechanisms of the influence by periodontitis. This will provide a theoretical basis for the new ideas on prevention and treatment of oculopathy.

[Clinical analysis of chronic eosinophilic pneumonia in 9 cases]

Objective: To investigate the clinical features, treatment and prognosis of chronic eosinophilic pneumonia. Methods: Nine patients with chronic eosinophilic pneumonia diagnosed in Shandong Provincial Qianfoshan Hospital from January 2014 to December 2020 were enrolled and followed up. The data of clinically proven chronic eosinophilic pneumonia were reviewed. Results: The 9 cases included one male and eight females, aged from 16 to 71 years (median 47 years). Among them, 5 cases were complicated with asthma, 1 case was complicated with allergic rhinitis, and 1 case had an allergic history of pollen. All the patients had cough, expectoration, chest tightness and wheezing, and a few had fatigue (3/9), fever (1/9) and chest pain (1/9). Single or multiple patchy high-density shadows (9/9), mediastinal lymphadenopathy (7/9), air bronchogram (2/9), and reticular shadow (1/9) were observed in chest CT. Peripheral eosinophils (EOS) and serum total IgE increased to varying degrees in the 9 patients. Meanwhile, the bronchoscopy of 5 cases showed elevated percentage of eosinophils in alveolar lavage fluid, and the lung biopsy of remaining 4 cases showed EOS infiltration in lung alveolar and interstitium. After receiving glucocorticoid therapy for 0.5 to 1 month, the clinical symptoms of all 9 patients had been improved and lung lesions on CT scans had been obviously absorbed. Four cases relapsed during follow-up. Conclusions: For patients especially women who have a history of allergy, elevated blood eosinophils and serum total IgE with pulmonary high-density shadow or consolidation, chronic eosinophilic pneumonia should be considered, and bronchoscopy or percutaneous lung biopsy is indicated for a definite diagnosis. Glucocorticoid therapy is effective, but the rate of recurrence is high.

Bismuth Nanoparticle and Polyhydroxybutyrate Coatings Enhance the Radiopacity of Absorbable Inferior Vena Cava Filters for Fluoroscopy-Guided Placement and Longitudinal Computed Tomography Monitoring in Pigs

Inferior vena cava filters (IVCFs) constructed with poly-p-dioxanone (PPDO) are promising alternatives to metallic filters and their associated risks and complications. Incorporating high-Z nanoparticles (NPs) improves PPDO IVCFs' radiopacity without adversely affecting their safety or performance. However, increased radiopacity from these studies are insufficient for filter visualization during fluoroscopy-guided PPDO IVCF deployment. This study focuses on the use of bismuth nanoparticles (BiNPs) as radiopacifiers to render sufficient signal intensity for the fluoroscopy-guided deployment and long-term CT monitoring of PPDO IVCFs. The use of polyhydroxybutyate (PHB) as an additional layer to increase the surface adsorption of NPs resulted in a 2-fold increase in BiNP coating (BiNP-PPDO IVCFs, 3.8%; BiNP-PPDO + PHB IVCFs, 6.2%), enabling complete filter visualization during fluoroscopy-guided IVCF deployment and, 1 week later, clot deployment. The biocompatibility, clot-trapping efficacy, and mechanical strength of the control PPDO (load-at-break, 6.23 ± 0.13 kg), BiNP-PPDO (6.10 ± 0.09 kg), and BiNP-PPDO + PHB (6.15 ± 0.13 kg) IVCFs did not differ significantly over a 12-week monitoring period in pigs. These results indicate that BiNP-PPDO + PHB can increase the radiodensity of a novel absorbable IVCF without compromising device strength. Visualizing the device under conventional radiographic imaging is key to allow safe and effective clinical translation of the device.

Deployment of an Interventional Radiology Telemedicine Program During the COVID-19 Pandemic: Initial Experience With 10,056 Visits

Objective

To evaluate the clinical, operational, and financial effects of using telemedicine services in an academic interventional radiology setting during the coronavirus disease 2019 pandemic and to identify potential barriers to equitable telemedicine access for patients.

Methods

Evaluation and management (E&M) data over a 104-week period from September 2019 to August 2021 were reviewed. Data related to the visits were recorded including visit type, billing provider, patient demographic information, Current Procedural Terminology code charged, and reimbursement received. The ZIP code pertaining to the patient’s primary residence was matched with median household income from the US Census Bureau.

Results

In all, 14,754 E&M encounters were performed over the study period, of which 10,056 were conducted using telemedicine. Twenty-two percent of visits were performed with interactive video; the remainder were performed using audio only. Female patients were more likely than male patients to use interactive video visits for telemedicine encounters (23.7% versus 20.4%, P < .001). Patients availing of video visits (mean age, 58.1 years, SD = 14.0) were also significantly younger than those patients who used audio-only (telephone) encounters (mean age, 62.5 years, SD = 13.3). Patients with private insurance and those living in neighborhoods with higher median household income were more likely to avail of interactive video visits (P < .001). Professional E&M monthly revenue was between 23.3% and 53.2% of peak prepandemic levels (mean 37.7%).

Conclusion

Telemedicine services allowed for rapid restoration of E&M encounter volumes over the study period. Further work is required to determine the potential implementation barriers to increasing the use of video visits.

Safety and efficacy of percutaneous transabdominal and transesophageal decompression gastric catheters for palliation of malignant bowel obstruction

PURPOSE

To evaluate the safety and primary technical success rate of gastric decompression via percutaneous transabdominal gastrostomy (PTAG) or percutaneous transesophageal gastric (PTEG) catheter placement for management of malignant bowel obstruction (MBO). A secondary purpose was to evaluate the safety and success rate for PTAG catheter placement in patients with both MBO and ascites.

METHODS

A single-institution retrospective review of 385 patients who underwent attempted decompression gastric catheter placement from March 2013 to August 2018 was performed. Medical records and imaging studies were reviewed. A subgroup of patients with concomitant MBO and ascites were identified. The primary outcome measures were procedural technical success and procedural complications.

RESULTS

394 decompression gastrostomy catheters were attempted from 2013 to 2018, n = 353 PTAG and n = 41 PTEG. The success rate was 95.5% (n = 337 of 353) for PTAG and 97.6% (n = 40 of 41) for PTEG. There were 63 total complications involving 47 (13.9%) patients following PTAG and 13 total complications involving 9 (22.5%) patients following PTEG, P = 0.16. For the subgroup of patients with MBO and ascites, the success rate was 94.8% (n = 182 of 192 patients), and there were 20 complications involving 17 (12.9%) of 132 patients.

CONCLUSION

Gastric decompression for patients with MBO via PTAG or PTEG catheter placement is associated with high success rates and low complications.

Evaluation of Ultrafast Wave-Controlled Aliasing in Parallel Imaging 3D-FLAIR in the Visualization and Volumetric Estimation of Cerebral White Matter Lesions

BACKGROUND AND PURPOSE

Our aim was to evaluate an ultrafast 3D-FLAIR sequence using Wave-controlled aliasing in parallel imaging encoding (Wave-FLAIR) compared with standard 3D-FLAIR in the visualization and volumetric estimation of cerebral white matter lesions in a clinical setting.

MATERIALS AND METHODS

Forty-two consecutive patients underwent 3T brain MR imaging, including standard 3D-FLAIR (acceleration factor = 2, scan time = 7 minutes 50 seconds) and resolution-matched ultrafast Wave-FLAIR sequences (acceleration factor  = 6, scan time = 2 minutes 45 seconds for the 20-channel coil; acceleration factor = 9, scan time  = 1 minute 50 seconds for the 32-channel coil) as part of clinical evaluation for demyelinating disease. Automated segmentation of cerebral white matter lesions was performed using the Lesion Segmentation Tool in SPM. Student t tests, intraclass correlation coefficients, relative lesion volume difference, and Dice similarity coefficients were used to compare volumetric measurements among sequences. Two blinded neuroradiologists evaluated the visualization of white matter lesions, artifacts, and overall diagnostic quality using a predefined 5-point scale.

RESULTS

Standard and Wave-FLAIR sequences showed excellent agreement of lesion volumes with an intraclass correlation coefficient of 0.99 and mean Dice similarity coefficient of 0.97 (SD, 0.05) (range, 0.84-0.99). Wave-FLAIR was noninferior to standard FLAIR for visualization of lesions and motion. The diagnostic quality for Wave-FLAIR was slightly greater than for standard FLAIR for infratentorial lesions (P < .001), and there were fewer pulsation artifacts on Wave-FLAIR compared with standard FLAIR (P < .001).

CONCLUSIONS

Ultrafast Wave-FLAIR provides superior visualization of infratentorial lesions while preserving overall diagnostic quality and yields white matter lesion volumes comparable with those estimated using standard FLAIR. The availability of ultrafast Wave-FLAIR may facilitate the greater use of 3D-FLAIR sequences in the evaluation of patients with suspected demyelinating disease.

Severity of Chest Imaging is Correlated with Risk of Acute Neuroimaging Findings among Patients with COVID-19

BACKGROUND AND PURPOSE

Severe respiratory distress in patients with COVID-19 has been associated with higher rate of neurologic manifestations. Our aim was to investigate whether the severity of chest imaging findings among patients with coronavirus disease 2019 (COVID-19) correlates with the risk of acute neuroimaging findings.

MATERIALS AND METHODS

This retrospective study included all patients with COVID-19 who received care at our hospital between March 3, 2020, and May 6, 2020, and underwent chest imaging within 10 days of neuroimaging. Chest radiographs were assessed using a previously validated automated neural network algorithm for COVID-19 (Pulmonary X-ray Severity score). Chest CTs were graded using a Chest CT Severity scoring system based on involvement of each lobe. Associations between chest imaging severity scores and acute neuroimaging findings were assessed using multivariable logistic regression.

RESULTS

Twenty-four of 93 patients (26%) included in the study had positive acute neuroimaging findings, including intracranial hemorrhage (n = 7), infarction (n = 7), leukoencephalopathy (n = 6), or a combination of findings (n = 4). The average length of hospitalization, prevalence of intensive care unit admission, and proportion of patients requiring intubation were significantly greater in patients with acute neuroimaging findings than in patients without them (P < .05 for all). Compared with patients without acute neuroimaging findings, patients with acute neuroimaging findings had significantly higher mean Pulmonary X-ray Severity scores (5.0 [SD, 2.9] versus 9.2 [SD, 3.4], P < .001) and mean Chest CT Severity scores (9.0 [SD, 5.1] versus 12.1 [SD, 5.0], P = .041). The pulmonary x-ray severity score was a significant predictor of acute neuroimaging findings in patients with COVID-19.

CONCLUSIONS

Patients with COVID-19 and acute neuroimaging findings had more severe findings on chest imaging on both radiographs and CT compared with patients with COVID-19 without acute neuroimaging findings. The severity of findings on chest radiography was a strong predictor of acute neuroimaging findings in patients with COVID-19.

Overall Body Composition and Sarcopenia Are Associated with Poor Liver Hypertrophy Following Portal Vein Embolization

PURPOSE

To explore whether body composition and/or sarcopenia are associated with liver hypertrophy following portal vein embolization (PVE) in patients with colorectal liver metastases (CLM).

METHODS

Patients with CLM who underwent right PVE prior to a planned right hepatectomy were identified from the institutional liver database from 2004 to 2014. Patients were excluded due to previous liver-directed therapy/hepatectomy, right PVE + segment IV embolization, or planned 2-stage hepatectomy. Advanced imaging software was used to measure body compartment volumes (cm²), which were standardized to height (m²) to create an index: skeletal muscle index (SMI), subcutaneous adipose index (SAI), and visceral adipose index (VAI). SMI, gender, and body mass index (BMI) were used to define sarcopenia. The main outcome of interest was hypertrophy of the future liver remnant (FLR) following PVE, which was reported as degree of hypertrophy (DH) and kinetic growth rate (KGR).

RESULTS

Patients were evenly divided into three KGR groups: lower third (KGR:0.7-2.0%), middle third (KGR:2.0-4.1%), and upper third (KGR:4.2-12.3%). Patients in the lower third KGR group had a lower VAI (31.0 vs 53.0 vs 54.5 cm²/m², p = 0.042) and were more commonly sarcopenic (60%) compared to the upper third (20%, p = 0.025). Eighteen patients (40%) met criteria for sarcopenia. Sarcopenic patients had a lower VAI (29.1 vs 57.4 cm²/m², p = 0.004), lesser degree of hypertrophy (8.3% vs 15.2%, p = 0.009), and lower KGR (2.0% vs 4.0%, p = 0.012).

CONCLUSION

Sarcopenia and associated body composition indices are strongly associated with clinically relevant impaired liver regeneration, which may result in increased liver-specific complications following hepatectomy for CLM.

Remediation of arsenic-contaminated paddy soil by intercropping aquatic vegetables and rice

Soil contamination by arsenic (As) is an important environmental issue globally. Intercropping of hyperaccumulators with main crop is typically applied for remediation of As-contaminated soil. Most hyperaccumulators are wild plants with small biomass and slow growth rates. Thus, remediation is slow. Here, we propose an effective intercropping system for remediation of As-contaminated paddy soil. Four treatments-intercropping with water spinach (Ipomoea aquatica Forsk) (T1), water celery (Oenanthe javanica (Blume) DC.) (T2), or Guangdong white arrowhead (Sagittaria sagittifolia L. var) (T3), with rice (Oryza sativa L.) monoculture (control, CK)-were used. Compared with the CK, grain yield per plant of rice under T1 and T2 increased by 58.13% and 10.48%, respectively, but decreased by 46.90% in T3. As concentration, bioaccumulation factor, and translocation factor in brown rice were significantly lower in the intercropping treatments than in CK. As removal by water spinach was 7.04 and 1.47 times that by water celery and arrowhead, respectively. The pH of paddy soil was significantly higher in all treatments than in CK, and iron plaque on rice roots under T1 and T2 decreased significantly but increased significantly under T3 compared with that of CK. Rice intercropped with water spinach had the best remediation effect. Novelty Statement: We believe that the following highlights of this manuscript will make it interesting to general readers of this journal.First, in recent years, many articles about intercropping system for the remediation of soil heavy metal pollution focus on dry land, and few studies have focused on paddy soil. The present study was on arsenic-contaminated paddy soil remediation.Second, water spinach, water celery, and arrowhead have great potential for phytoremediation. Studies have shown that these three aquatic vegetables play a role in the removal of certain pollutants, such as heavy metals. Moreover, when intercropped with rice, they can effectively increase rice yield and reduce rice diseases and insect pests. However, studies on remediation of arsenic-contaminated soil by intercropping aquatic vegetables and rice have not been reported. We propose here a rice-aquatic vegetables (water spinach, water celery and arrowhead) intercropping pattern for remediation of arsenic in soil.Third, according to the arsenic concentration and removal rate, we used a bioaccumulation factor, translocation factor, and arsenic removal per unit area of plants for the quantitative evaluation of the remediation effects of the intercropping systems. We found that the intercropping of rice and water spinach could be used to remediate arsenic-contaminated soil. Moreover, the extraction contents of arsenic using intercropping with water spinach was higher than that achieved in a previous study that applied intercropping with the arsenic hyperaccumulator Pteris vittata over the same growth time. This study provides a reference for realizing both remediation and increased production in arsenic-contaminated soil and for promoting sustainable development of agriculture.

Optimization of the differentiation and quantification of high-Z nanoparticles incorporated in medical devices for CT-guided interventions

PURPOSE

Material differentiation has been made possible using dual-energy computed tomography (DECT), in which the unique, energy-dependent attenuating characteristics of materials can provide new diagnostic information. One promising application is the clinical integration of biodegradable polymers as temporary implantable medical devices impregnated with high-atomic number (high-Z) materials. The purpose of this study was to explore the incorporation of high atomic number (high-Z) contrast materials in a bioresorbable inferior vena cava filter for advanced CT-based monitoring of its location and differentiating from surrounding materials.

MATERIALS AND METHODS

Imaging optimization and calibration studies were performed using a body phantom. The dual-energy CT (DECT) ratios for iron, zirconium, barium, gadolinium, ytterbium, tantalum, tungsten, gold, and bismuth were generated for peak kilovoltage combinations of 80/150Sn, 90/150Sn, and 100/150Sn kVp in dual-source CT via linear regression of the CT numbers at low and high energies. A secondary calibration of the material map to the nominal material concentration was generated to correct for use of materials other than iodine. CT number was calibrated to the material concentration based on single-energy CT (SECT) with additional filtration (150Sn kVp). These quantification methods were applied to monitoring of biodegradable inferior vena cava filters (IVCFs) made of braided poly(p-dioxanone) sutures infused with ultrasmall bismuth nanoparticles (BiNPs) implanted in an adult domestic pig.

RESULTS

Qualitative material differentiation was optimal for high-Z (>73) contrast agents in DECT. However, quantification became nonlinear and inaccurate as the K-edge of the material increased. Using the high-energy (150Sn kVp) data component as a SECT scan, the linearity of quantification curves was maintained with lower limits of detection than with DECT. Among the materials tested, bismuth had optimal differentiation from iodine in DECT while maintaining increased contrast in high-energy SECT for quantification (11.5% error). Coating the IVCF with BiNPs resulted in markedly greater radiopacity (maximum CT number, 2028 HU) than that of an uncoated IVCF (maximum CT number, 127 HU). Using DECT imaging and processing, the BiNP-IVCF could be clearly differentiated from iodine contrast injected into the inferior vena cava of the pig.

CONCLUSIONS

These findings may improve widespread integration of medical devices incorporated with high-Z materials into the clinic, where technical success, possible complications, and device integrity can be assessed intraoperatively and postoperatively via DECT imaging.

Intratumoral Injection of Clostridium novyi-NT Spores in Patients with Treatment-refractory Advanced Solid Tumors

PURPOSE

Intratumorally injected Clostridium novyi-NT (nontoxic; lacking the alpha toxin), an attenuated strain of C. novyi, replicates within hypoxic tumor regions resulting in tumor-confined cell lysis and inflammatory response in animals, which warrants clinical investigation.

PATIENTS AND METHODS

This first-in-human study (NCT01924689) enrolled patients with injectable, treatment-refractory solid tumors to receive a single intratumoral injection of C. novyi-NT across 6 dose cohorts (1 × 10⁴ to 3 × 10⁶ spores, 3+3 dose-escalation design) to determine dose-limiting toxicities (DLT), and the maximum tolerated dose.

RESULTS

Among 24 patients, a single intratumoral injection of C. novyi-NT led to bacterial spores germination and the resultant lysis of injected tumor masses in 10 patients (42%) across all doses. The cohort 5 dose (1 × 10⁶ spores) was defined as the maximum tolerated dose; DLTs were grade 4 sepsis (n = 2) and grade 4 gas gangrene (n = 1), all occurring in three patients with injected tumors >8 cm. Other treatment-related grade ≥3 toxicities included pathologic fracture (n = 1), limb abscess (n = 1), soft-tissue infection (n = 1), respiratory insufficiency (n = 1), and rash (n = 1), which occurred across four patients. Of 22 evaluable patients, nine (41%) had a decrease in size of the injected tumor and 19 (86%) had stable disease as the best overall response in injected and noninjected lesions combined. C. novyi-NT injection elicited a transient systemic cytokine response and enhanced systemic tumor-specific T-cell responses.

CONCLUSIONS

Single intratumoral injection of C. novyi-NT is feasible. Toxicities can be significant but manageable. Signals of antitumor activity and the host immune response support additional studies of C. novyi-NT in humans.

Durability of partial splenic artery embolization on platelet counts for cancer patients with hypersplenism-related thrombocytopenia

PURPOSE

Partial splenic artery embolization (PSAE) has shown promise in increasing platelet counts in cancer patients with hypersplenism-related thrombocytopenia. The purpose of this study was to identify response predictors and to longitudinally evaluate PSAE efficacy and durability in a large cohort of cancer patients with hypersplenism-related thrombocytopenia.

METHODS

A single-institution, IRB-approved, HIPAA-compliant retrospective review of all PSAEs for thrombocytopenia between 2012 and 2015 was performed. Patients were classified as complete responders (CR, no platelet value < 100 × 10⁹/L following PSAE), partial responders (PR, initial increase in platelets but subsequent decrease in platelets < 100 × 10⁹/L), and non-responders (NR, platelets never > 100 × 10⁹/L following PSAE).

RESULTS

Of the 98 patients included in the study, 58 had CR (59%), 28 had PR (29%), and 12 patients had NR (12%). The percent splenic tissue embolized was significantly greater in the CR group compared to the PR group (P = 0.001). The percent volume of splenic tissue embolized was linearly correlated with the magnitude of platelet increase without a minimum threshold. At least one line of chemotherapy was successfully restarted in 97% of patients, and 41% of patients did not experience recurrence of thrombocytopenia for the duration of their survival. The major complication rate was 8%, with readmission following initial hospitalization for persistent "post-embolization syndrome" symptoms the most common.

CONCLUSIONS

In cancer patients with hypersplenism-related thrombocytopenia, PSAE is a safe intervention that effects a durable elevation in platelet counts across a range of malignancies and following the re-initiation of chemotherapy.

Transjugular Intrahepatic Portosystemic Shunts Reduce Variceal Bleeding and Improve Survival in Patients with Cirrhosis: A Population-Based Analysis

PURPOSE

To investigate from a population health perspective the effects of transjugular intrahepatic portosystemic shunt (TIPS) creation on recurrent variceal bleeding and survival in patients with cirrhosis.

MATERIALS AND METHODS

Patients with cirrhosis who presented to outpatient and acute-care hospitals in California (2005-2011) and Florida (2005-2014) with variceal bleeding comprised the study cohort. Patients entered the study cohort at their first presentation for variceal bleeding; all subsequent hospital encounters were then evaluated to determine subsequent interventions, complications, and mortality data.

RESULTS

A total of 655,577 patients with cirrhosis were identified, of whom 42,708 (6.5%) had at least 1 episode of variceal bleeding and comprised the study cohort. The median follow-up time was 2.61 years. A TIPS was created in 4,201 (9.8%) of these patients. There were significantly greater incidences of coagulopathy (83.9% vs 72.8%; P < .001), diabetes (45.5% vs 38.8%; P < .001), and hepatorenal syndrome (15.3% vs 12.5%; P < .001) in TIPS recipients vs those without a TIPS. Following propensity-score matching, TIPS recipients were found to have improved overall survival (82% vs 77% at 12 mo; P < .001) and a lower rate of recurrent variceal bleeding (88% vs 83% recurrent bleeding-free survival at 12 months,; P < .001) than patients without a TIPS. Patients with a TIPS had a significant increase in encounters for hepatic encephalopathy vs those without (1.01 vs 0.49 per year; P < .001).

CONCLUSIONS

TIPS improves recurrent variceal bleeding rates and survival in patients with cirrhosis complicated by variceal bleeding. However, TIPS creation is also associated with a significant increase in hepatic encephalopathy.

Evaluation of Ultrafast Wave-CAIPI MPRAGE for Visual Grading and Automated Measurement of Brain Tissue Volume

BACKGROUND AND PURPOSE

Volumetric brain MR imaging typically has long acquisition times. We sought to evaluate an ultrafast MPRAGE sequence based on Wave-CAIPI (Wave-MPRAGE) compared with standard MPRAGE for evaluation of regional brain tissue volumes.

MATERIALS AND METHODS

We performed scan-rescan experiments in 10 healthy volunteers to evaluate the intraindividual variability of the brain volumes measured using the standard and Wave-MPRAGE sequences. We then evaluated 43 consecutive patients undergoing brain MR imaging. Patients underwent 3T brain MR imaging, including a standard MPRAGE sequence (acceleration factor [R] = 2, acquisition time [TA] = 5.2 minutes) and an ultrafast Wave-MPRAGE sequence (R = 9, TA = 1.15 minutes for the 32-channel coil; R = 6, TA = 1.75 minutes for the 20-channel coil). Automated segmentation of regional brain volume was performed. Two radiologists evaluated regional brain atrophy using semiquantitative visual rating scales.

RESULTS

The mean absolute symmetrized percent change in the healthy volunteers participating in the scan-rescan experiments was not statistically different in any brain region for both the standard and Wave-MPRAGE sequences. In the patients undergoing evaluation for neurodegenerative disease, the Dice coefficient of similarity between volumetric measurements obtained from standard and Wave-MPRAGE ranged from 0.86 to 0.95. Similarly, for all regions, the absolute symmetrized percent change for brain volume and cortical thickness showed <6% difference between the 2 sequences. In the semiquantitative visual comparison, the differences between the 2 radiologists' scores were not clinically or statistically significant.

CONCLUSIONS

Brain volumes estimated using ultrafast Wave-MPRAGE show low intraindividual variability and are comparable with those estimated using standard MPRAGE in patients undergoing clinical evaluation for suspected neurodegenerative disease.

In vivo performance of gold nanoparticle-loaded absorbable inferior vena cava filters in a swine model

Absorbable inferior vena cava filters (IVCFs) offer a promising alternative to metallic retrievable filters in providing protection against pulmonary embolism (PE) for patients contraindicated for anticoagulant therapy. However, because absorbable filters are not radiopaque, monitoring of the filter using conventional X-ray imaging modalities (e.g. plain film radiographs, computed tomography [CT] and fluoroscopy) during deployment and follow-up is not possible and represents a potential obstacle to widespread clinical integration of the device. Here, we demonstrate that gold nanoparticles (AuNPs) infused into biodegradable filters made up of poly-p-dioxanone (PPDO) may improve device radiopacity without untoward effects on device efficacy and safety, as assessed in swine models for 12 weeks. The absorbable AuNP-infused filters demonstrated significantly improved visualization using CT without affecting tensile strength, in vitro degradation, in vivo resorption, or thrombus-capturing efficacy, as compared to similar non-AuNPs infused resorbable IVCFs. This study presents a significant advancement to the development of imaging enhancers for absorbable IVCFs.

[Effect and underling mechanism of 6% hydroxyethyl starch 130/0.4 on serum albumen in trauma orthopedic patients during operation]

Objective: To investigate the effect of 6% hydroxyethyl starch 130/0.4(HES) on protein in severe trauma orthopedic patients after acute hemodilution. Methods: Fourty-eight severe trauma patients who met the inclusion criteria were selected from June 2018 to December 2018 in Yantaishan Hospital, and were randomly divided into two groups (n=24): group A and group B. Group A was ringer's sodium lactate control group, and group B was HES treatment group. After the tracheal intubation, the patients of group A were infused with 10% blood volume of sodium lactate ringer at 0.5 ml·kg(-1)·min(-1), and the patients in group B were infused with 10% blood volume of HES at 0.5 ml·kg(-1)·min(-1). Total protein (TP), human serum albumin (HSA), numbers of circulating endothelium cells (CEC), C-reactive protein (CRP), and serum levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-10 and IL-6 were measured immediately after acute hemodilution (T(0)), 24 hours (T(1)) and 48 hours (T(2)) after acute hemodilution. After infusion into human body, HES bond to HSA, and fluorescence spectroscopy was used to analyze the binding relationship between HES and HSA in order to further study the effects of HES on HSA. Results: The HSA, TP, CEC, TNF-α, IL-6, IL-10, CRP at T(0) of group A were (38±5) g/L, (66±5) g/L, (5.5±0.4)/0.9 μl, (24±5) μg/L, (8.9±0.8) μg/L, (44±6) μg/L, (13.6±1.4) mg/L; While at T(1) were (33±5) g/L, (60±6) g/L, (10.2±0.7)/0.9 μl, (87±9) μg/L, (38.8±2.3) μg/L, (57±7) μg/L, (23.4±2.4) mg/L. The HSA, TP, CEC, TNF-α, IL-6, IL-10, CRP at T(0) of group B were(38±4)g/L, (66±5) g/L, (5.4±0.6)/0.9 μl, (24±6) μg/L, (9.1±0.9) μg/L, (45±6) μg/L, (13.4±1.8) mg/L; While at T(1) were (35±5)g/L, (62±5)g/L, (7.4±0.6)/0.9 μl, (70±8) μg/L, (29.5±3.1) μg/L, (72±6) μg/L, (19.7±2.2) mg/L. HSA and TP decreased at T(1) in group A as compared with T(0) (P<0.05), contrarily CEC increased significantly at T(1), TNF-ɑ, IL-6, IL-10 and CRP augmented at T(1) and T(2) in two groups (P<0.05). In comparison with the patients of group A, CEC decreased significantly at T(1) (P<0.05). TNF-ɑ, IL-6, CRP reduced significantly at T(1) and T(2) (P<0.05), but IL-10 increased at T(1) and T(2) in group B (P<0.05). The secondary structure of HSA changed after HES was added in the HES solution. The fluorescence intensity of HSA decreased with the increase of HES concentration,which suggested that HES induced HSA fluorescence quenching. HES could bind to Trp-214 residue in HSA at a molecular ration of 1∶1. Conclusions: 6% HES reduces the occurrence of low protein level in severe trauma patients after operation. HES could bind to Trp-214 amino acid residue in HSA and form the complex at a molecular ratio of 1∶1. The formation of HES-HSA complex increases the volume of HES, avoids the vascular leakage, protects the vascular endothelial cells, and induces anti-inflammatory immunity in the patients with capillary syndrome.

Association of Inferior Vena Cava Filter Placement With Rates of Pulmonary Embolism in Patients With Cancer and Acute Lower Extremity Deep Venous Thrombosis

IMPORTANCE

Venous thromboembolism is the second overall leading cause of death for patients with cancer, and there is an approximately 2-fold increase in fatal pulmonary embolism (PE) in patients with cancer. Inferior vena cava (IVC) filters are designed to prevent PE, but defining the appropriate use of IVC filters in patients with cancer remains a substantial unmet clinical need.

OBJECTIVE

To evaluate the association of IVC filters with the development of PE in patients with cancer and deep venous thrombosis (DVT).

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted using administrative data on 88 585 patients from the state inpatient databases for California (2005-2011) and Florida (2005-2014). Based on diagnostic and procedure codes, patients with cancer and acute lower extremity DVT were identified. All subsequent hospital visits for these patients were evaluated for the placement of an IVC filter, the development of new PE, the development of new DVT, and in-hospital mortality. Data analysis was performed from September 1 to December 1, 2019.

EXPOSURES

Placement of an IVC filter.

MAIN OUTCOMES AND MEASURES

The association of IVC filter placement with rates of new PE and DVT was estimated using a propensity score matching algorithm and competing risk analysis.

RESULTS

The study cohort comprised 88 585 patients (45 074 male; median age, 71.0 years [range, 1.0-104.0 years]) with malignant neoplasms who presented to a health care institution with a diagnosis of acute lower extremity DVT. Of these patients, 33 740 (38.1%) underwent IVC filter placement; patients with risk factors such as upper gastrointestinal bleeding (odds ratio, 1.32; 95% CI, 1.29-1.37), intracranial hemorrhage (odds ratio, 1.21; 95% CI, 1.19-1.24), and coagulopathy (odds ratio, 1.09; 95% CI, 1.08-1.10) were more likely to receive an IVC filter. A total of 4492 patients (5.1%) developed a new PE after their initial DVT diagnosis. There was a significant improvement in PE-free survival for these patients compared with those who did not receive IVC filters across the full, unbalanced study cohort as well as after propensity score matching and competing risk analysis (hazard ratio, 0.69; 95% CI, 0.64-0.75; P < .001). Furthermore, IVC filter placement reduced the development of PE in patients with very high-risk malignant neoplasms (eg, pancreaticobiliary cancer), high-risk malignant neoplasms (eg, lung cancer), and low-risk malignant neoplasms (eg, prostate cancer). After accounting for anticoagulation use and imbalanced risk factors, IVC filter placement did not increase the risk of new DVT development.

CONCLUSIONS AND RELEVANCE

This study suggests that, for patients with cancer and DVT and bleeding risk factors, IVC filter placement is associated with an increased rate of PE-free survival.

Hepatic vein embolization after portal vein embolization to induce additional liver hypertrophy in patients with metastatic colorectal carcinoma

OBJECTIVES

To assess the effect of salvage hepatic vein embolization (HVE) on the volume of the future liver remnant (FLR) for patients with metastatic colorectal cancer (mCRC) and inadequate hypertrophy following initial portal vein embolization (PVE).

METHODS

From April 2011 to October 2018, 9 patients with mCRC underwent HVE following PVE. The right or middle hepatic vein was embolized with coils and/or vascular plugs. Liver volumes were calculated at baseline, following PVE, and following HVE, in order to assess the hypertrophic effect of PVE and HVE on the FLR.

RESULTS

Nine patients underwent HVE (n = 3, right HVE; n = 6, middle HVE) because of inadequate FLR hypertrophy following PVE. The standardized FLR increased from 0.16 (median, range 0.08-0.24) at baseline to 0.22 (median, range 0.13-0.29) following PVE (p = 0.0005) to 0.26 (median, range 0.19-0.37) following HVE (p = 0.0050). HVE was performed 40 days (median, range 19-128 days) following PVE, and assessment of FLR hypertrophy was performed 41 days (median, range 19-92 days) following HVE. Four of nine patients underwent hepatectomy; 5 patients failed to undergo hepatectomy (n = 3, inadequate hypertrophy; n = 1, disease progression; n = 1, portal hypertension). One patient required repeat HVE due to a patent accessory vein.

CONCLUSIONS

Salvage HVE is an effective technique to induce additional FLR hypertrophy in patients with mCRC and inadequate FLR after initial PVE.

KEY POINTS

• Hepatic vein embolization is effective to induce additional liver hypertrophy in surgical patients with metastatic colorectal carcinoma and inadequate hypertrophy after portal vein embolization. • Increases in future liver remnant volume are feasible in patients who receive hepatotoxic neoadjuvant systemic therapy for metastatic colorectal carcinoma. • Sequential portal vein embolization and hepatic vein embolization can be a viable technique to induce liver hypertrophy in patients with small baseline future liver remnant volumes (< 20%).

Energy Cascade Rate Measured in a Collisionless Space Plasma with MMS Data and Compressible Hall Magnetohydrodynamic Turbulence Theory

The first complete estimation of the compressible energy cascade rate |ϵ_{C}| at magnetohydrodynamic (MHD) and subion scales is obtained in Earth's magnetosheath using Magnetospheric MultiScale spacecraft data and an exact law derived recently for compressible Hall MHD turbulence. A multispacecraft technique is used to compute the velocity and magnetic gradients, and then all the correlation functions involved in the exact relation. It is shown that when the density fluctuations are relatively small, |ϵ_{C}| identifies well with its incompressible analog |ϵ_{I}| at MHD scales but becomes much larger than |ϵ_{I}| at subion scales. For larger density fluctuations, |ϵ_{C}| is larger than |ϵ_{I}| at every scale with a value significantly higher than for smaller density fluctuations. Our study reveals also that for both small and large density fluctuations, the nonflux terms remain always negligible with respect to the flux terms and that the major contribution to |ϵ_{C}| at subion scales comes from the compressible Hall flux.

Absence of Evidence of Electrical Switching of the Antiferromagnetic Néel Vector

Much theoretical and experimental attention has been focused on the electrical switching of the antiferromagnetic (AFM) Néel vector via spin-orbit torque. Measurements employing multiterminal patterned structures of Pt/AFM show recurring signals of the supposedly planar Hall effect and magnetoresistance, implying AFM switching. We show in this Letter that similar signals have been observed in structures with and without the AFM layer, and of an even larger magnitude using different metals and substrates. These may not be the conclusive evidence of spin-orbit torque switching of AFM, but the thermal artifacts of patterned metal structure on substrate. Large current densities in the metallic devices, beyond the Ohmic regime, can generate unintended anisotropic thermal gradients and voltages. AFM switching requires unequivocal detection of the AFM Néel vector before and after SOT switching.

Validation of Highly Accelerated Wave-CAIPI SWI Compared with Conventional SWI and T2*-Weighted Gradient Recalled-Echo for Routine Clinical Brain MRI at 3T

BACKGROUND AND PURPOSE

SWI is valuable for characterization of intracranial hemorrhage and mineralization but has long acquisition times. We compared a highly accelerated wave-controlled aliasing in parallel imaging (CAIPI) SWI sequence with 2 commonly used alternatives, standard SWI and T2*-weighted gradient recalled-echo (T2*W GRE), for routine clinical brain imaging at 3T.

MATERIALS AND METHODS

A total of 246 consecutive adult patients were prospectively evaluated using a conventional SWI or T2*W GRE sequence and an optimized wave-CAIPI SWI sequence, which was 3-5 times faster than the standard sequence. Two blinded radiologists scored each sequence for the presence of hemorrhage, the number of microhemorrhages, and severity of motion artifacts. Wave-CAIPI SWI was then evaluated in head-to-head comparison with the conventional sequences for visualization of pathology, artifacts, and overall diagnostic quality. Forced-choice comparisons were used for all scores. Wave-CAIPI SWI was tested for superiority relative to T2*W GRE and for noninferiority relative to standard SWI using a 15% noninferiority margin.

RESULTS

Compared with T2*W GRE, wave-CAIPI SWI detected hemorrhages in more cases (P < .001) and detected more microhemorrhages (P < .001). Wave-CAIPI SWI was superior to T2*W GRE for visualization of pathology, artifacts, and overall diagnostic quality (all P < .001). Compared with standard SWI, wave-CAIPI SWI showed no difference in the presence or number of hemorrhages identified. Wave-CAIPI SWI was noninferior to standard SWI for the visualization of pathology (P < .001), artifacts (P < .01), and overall diagnostic quality (P < .01). Motion was less severe with wave-CAIPI SWI than with standard SWI (P < .01).

CONCLUSIONS

Wave-CAIPI SWI provided superior visualization of pathology and overall diagnostic quality compared with T2*W GRE and was noninferior to standard SWI with reduced scan times and reduced motion artifacts.

Imaging G-Ratio in Multiple Sclerosis Using High-Gradient Diffusion MRI and Macromolecular Tissue Volume

BACKGROUND AND PURPOSE

Remyelination represents an area of great therapeutic interest in multiple sclerosis but currently lacks a robust imaging marker. The purpose of this study was to use high-gradient diffusion MRI and macromolecular tissue volume imaging to obtain estimates of axonal volume fraction, myelin volume fraction, and the imaging g-ratio in patients with MS and healthy controls and to explore their relationship to neurologic disability in MS.

MATERIALS AND METHODS

Thirty individuals with MS (23 relapsing-remitting MS, 7 progressive MS) and 19 age-matched healthy controls were scanned on a 3T MRI scanner equipped with 300 mT/m maximum gradient strength using a comprehensive multishell diffusion MRI protocol. Macromolecular tissue volume imaging was performed to quantify the myelin volume fraction. Diffusion data were fitted to a 3-compartment model of white matter using a spheric mean approach to yield estimates of axonal volume fraction. The imaging g-ratio was calculated from the ratio of myelin volume fraction and axonal volume fraction. Imaging metrics were compared between groups using 2-sided t tests with a Bonferroni correction.

RESULTS

The mean g-ratio was significantly elevated in lesions compared with normal-appearing WM (0.74 vs 0.67, P < .001). Axonal volume fraction (0.17 vs 0.23, P < .001) and myelin volume fraction (0.17 vs 0.25, P < .001) were significantly lower in lesions than normal-appearing WM. Myelin volume fraction was lower in normal-appearing WM compared with that in healthy controls (0.25 vs 0.27, P = .009). Disability, as measured by the Expanded Disability Status Scale, was significantly associated with myelin volume fraction (β = -40.5, P = .001) and axonal volume fraction (β = -41.0, P = .016) in normal-appearing WM.

CONCLUSIONS

The imaging g-ratio may serve as a biomarker for the relative degree of axonal and myelin loss in MS.

Localised grey matter atrophy in multiple sclerosis is network-based: a coordinate-based meta-analysis

AIM

To test the network degeneration hypothesis in multiple sclerosis (MS) with a two-stage coordinate-based meta-analysis by: (1) characterising regional selectivity of grey matter (GM) atrophy and (2) testing for functional connectivity involving these regions.

MATERIALS AND METHODS

Meta-analytic sources included 33 journal articles (1,666 MS patients and 1,269 healthy controls) with coordinate-based results from voxel-based morphometry analysis demonstrating GM atrophy. Mass univariate and multivariate coordinate-based meta-analyses were performed to identify a convergent pattern of GM atrophy and determine inter-regional co-activation (as a surrogate of functional connectivity), with anatomical likelihood estimation and functional meta-analytic connectivity modelling, respectively.

RESULTS

Localised GM atrophy was demonstrated in the thalamus, putamen, caudate, sensorimotor cortex, insula, superior temporal gyrus, and cingulate gyrus. This convergent pattern of atrophy displayed significant inter-regional functional co-activations.

CONCLUSION

In MS, GM atrophy was regionally selective, and these regions were functionally connected. The meta-analytic model-based results of this study are intended to guide future development of quantitative neuroimaging markers for diagnosis, evaluating disease progression, and monitoring treatment response.

Phase Ib clinical investigation of intraperitoneal ipilimumab and nivolumab in patients with peritoneal carcinomatosis due to gynecologic malignancy

TPS5606

Background: The peritoneal cavity is a frequent site of metastasis and recurrence for gynecologic malignancy, including approximately 80% of epithelial ovarian cancer (EOC) that presents with peritoneal involvement. These observations have led to the use of intraperitoneal (IP) route of administration for traditional cytotoxic chemotherapy. IP immunotherapy is a recognized but under explored area of clinical investigation with many potential advantages. Indeed, IP administered antibodies in both animals and human subjects are associated with absent or much lower peripheral blood concentrations. In addition to higher local and lower systemic exposure, other theoretical advantages include preferential binding to intraperitoneal and intratumoral immune cells, and absorption through the draining lymphatics of the peritoneal cavity. These pelvic and peri-aortic lymph nodes represent the most relevant lymphoid organs and as such may be the ideal site for T cell activation and trafficking back to the peritoneal tumor. Methods: The trial (NCT03508570) is a single-institution phase Ib trial to determine the recommended phase II dosing (RP2D) of IP administration of nivolumab in combination with ipilimumab. For the purpose of dose finding, the assessment period for dose limiting toxicity (DLT) is 12 weeks. The trial starts with a safety lead-in to confirm the safety of IP nivolumab before combining it with ipilimumab. A maximum sample size of 12 will be used to find the RP2D for nivolumab, up to 24 patients for the combination, and a planned expansion will be carried out such that at least 12 EOC patients are treated at RP2D of the intraperitoneal combination strategy. The secondary objectives are to describe the pharmacokinetics and toxicities, and to estimate the clinical benefit rate for the expansion cohort. Translational objectives include description of immunologic and biologic changes in serial blood and IP fluid collections as well as pre and on-treatment biopsies. Eligibility criteria include recurrent or progressive biopsy-confirmed platinum resistant EOC or other gynecologic cancer with measurable peritoneal disease, and no exposure to prior treatment with checkpoint inhibition. Enrollment began in January of 2019 with 3 subjects enrolled to date. Accrual update will be provided at the annual meeting. Clinical trial information: NCT03508570.

Pulmonary Hemorrhage Following Percutaneous Computed Tomography-Guided Lung Biopsy: Retrospective Review of Risk Factors, Including Aspirin Usage

BACKGROUND

To evaluate the significance of aspirin, as well as, other potential confounding risk factors, on the incidence and volume of pulmonary hemorrhage in patients undergoing percutaneous computed tomography-guided lung biopsy.

METHODS

This retrospective study was approved by the institutional review board. Between September 2013 and December 2014, 252 patients taking aspirin underwent transthoracic computed tomography-guided lung biopsy. Patient, technical, and lesion-related risk factors were evaluated. Univariate analysis was performed with a Student's t test, chi-square test, or Fisher's exact test, as appropriate followed by multivariate logistic regression.

RESULTS

Of 252 patients, 49 (19.4%) continued or stopped aspirin ≤4 days prior to biopsy and 203 (80.6%) patients stopped aspirin ≥5 days prior to biopsy. Pulmonary hemorrhage occurred in 174 cases (69.0%). The median volume of hemorrhage was 3.74 cm³ (range, 0-163.5 cm³). Multivariate analysis revealed that lesion size (P < 0.0001) and lesion depth (P < 0.0001) were independent risk factors for the incidence of pulmonary hemorrhage, while lesion size (P = 0.0035), transgression of intraparenchymal vessels (P < 0.0001), and lesion depth (P = 0.0047) were independent risk factors for severity of hemorrhage. Aspirin stopped ≤4 days from a percutaneous lung biopsy was not associated with pulmonary hemorrhage.

CONCLUSION

Aspirin taken concurrently or stopped within 4 days of transthoracic lung biopsy is not an independent risk factor for pulmonary hemorrhage. The incidence of hemorrhage following lung biopsy is associated with lesion size and depth, while the severity of hemorrhage is associated with lesion size, depth, as well as traversal of intraparenchymal vessels.

Development of a predictive model for 6 month survival in patients with venous thromboembolism and solid malignancy requiring IVC filter placement

PURPOSE

Our purpose was to develop a predictive model for short-term survival (i.e. <6 months) following inferior vena cava filter placement in patients with venous thromboembolism (VTE) and solid malignancy.

METHODS

Clinical and laboratory parameters were retrospectively reviewed for patients with solid malignancy who received a filter between January 2009 and December 2011 at a tertiary care cancer center. Multivariate Cox proportional hazards modeling was used to assess variables associated with 6 month survival following filter placement in patients with VTE and solid malignancy. Significant variables were used to generate a predictive model.

RESULTS

397 patients with solid malignancy received a filter during the study period. Three variables were associated with 6 month survival: (1) serum albumin [hazard ratio (HR) 0.496, P < 0.0001], (2) recent or planned surgery (<30 days) (HR 0.409, P < 0.0001), (3) TNM staging (stage 1 or 2 vs. stage 4, HR 0.177, P = 0.0001; stage 3 vs. stage 4, HR 0.367, P = 0.0002). These variables were used to develop a predictive model to estimate 6 month survival with an area under the receiver operating characteristic curve of 0.815, sensitivity of 0.782, and specificity of 0.715.

CONCLUSIONS

Six month survival in patients with VTE and solid malignancy requiring filter placement can be predicted from three patient variables. Our predictive model could be used to help physicians decide whether a permanent or retrievable filter may be more appropriate as well as to assess the risks and benefits for filter retrieval within the context of survival longevity in patients with cancer.

Compressible Magnetohydrodynamic Turbulence in the Earth's Magnetosheath: Estimation of the Energy Cascade Rate Using in situ Spacecraft Data

The first estimation of the energy cascade rate |ε_{C}| of magnetosheath turbulence is obtained using the Cluster and THEMIS spacecraft data and an exact law of compressible isothermal magnetohydrodynamics turbulence. The mean value of |ε_{C}| is found to be close to 10^{-13}  J m^{-3} s^{-1}, at least 2 orders of magnitude larger than its value in the solar wind (∼10^{-16}  J m^{-3} s^{-1} in the fast wind). Two types of turbulence are evidenced and shown to be dominated either by incompressible Alfvénic or compressible magnetosoniclike fluctuations. Density fluctuations are shown to amplify the cascade rate and its spatial anisotropy in comparison with incompressible Alfvénic turbulence. Furthermore, for compressible magnetosonic fluctuations, large cascade rates are found to lie mostly near the linear kinetic instability of the mirror mode. New empirical power-laws relating |ε_{C}| to the turbulent Mach number and to the internal energy are evidenced. These new findings have potential applications in distant astrophysical plasmas that are not accessible to in situ measurements.