Effectiveness and Safety of Large-Bore Aspiration Thrombectomy for Intermediate- or High-Risk Pulmonary Embolism.

PURPOSE: To evaluate effectiveness and safety of large-bore mechanical thrombectomy of intermediate- or high-risk pulmonary embolism (PE) and factors associated with effectiveness. MATERIALS AND METHODS: A retrospective review of 257 patients with intermediate- or high-risk PE who underwent mechanical thrombectomy using the Flowtriever system (Inari Medical, Irvine, California) between July 2019 and November 2021 was conducted. Data were analyzed using the linear regression and Kaplan-Meier methods with a Type 1 error set at 0.05. RESULTS: Patients' mean age was 62 years, and 51% were male. PE risk was classified as high, intermediate-high, and intermediate-low in 37 (14%), 201 (78%), and 18 (7%) of the patients, respectively. Procedural technical success was 100%. The mean pulmonary artery pressure (MPAP) decreased from a mean of 32 mmHg (SD ± 9) before to 24 mmHg (SD ± 9) after thrombectomy (mean decrease, 8 mmHg [SD ± 6]; P < .0001). Immediate complications occurred in 2% of the patients. Postprocedural 30-day and all-time PE-attributable mortality in a mean of 1.3-year follow-up was 2% and 6%, respectively. In multivariate analysis, the presence of lower extremity DVT at presentation (ß ± SE, -7.60 ± 3.22; P = .019) and a higher prethrombectomy MPAP (ß ± SE, -0.19 ± 0.04; P < .001) were associated with lower degrees of decrease in MPAP in the intermediate-high-risk PE group. Among 14 patients with postthrombectomy PE-attributable mortality, 13 had postthrombectomy MPAPs of >20 mmHg. CONCLUSIONS: Large-bore aspiration thrombectomy is a safe and effective treatment for reducing PAP in patients with intermediate- or high-risk PE. Postthrombectomy MPAPs of >20 mmHg might indicate postthrombectomy PE-attributable mortality in high-risk patients.

Uterine Fibroid Embolization or Myomectomy: How Much Marketing Is Enough? Comparative Analysis of Public Search Trends in Google and Medical Publications in PubMed.

To compare public popularity and volume of scientific publications regarding uterine fibroid embolization (UFE) and myomectomy. Google Trends and PubMed data were queried to assess temporal variations in online public search volumes and number of research publications for UFE and myomectomy. Time series analysis was used to identify meaningful temporal trends and forecast a future trend. Compared with UFE, myomectomy had significantly higher volumes of public online search and research publications, with an increasing trend over time (P < .0001). The forecasting models predicted a continuing increase in both public search volumes and number of research publications for myomectomy and static future trends in these metrics for UFE. This study signals significantly lower public popularity and research efforts for UFE compared with myomectomy for uterine fibroids. More effective marketing strategies and further research support will be needed to fill this gap.

Targeted Nanoparticles with High Heating Efficiency for the Treatment of Endometriosis with Systemically Delivered Magnetic Hyperthermia.

Endometriosis is a devastating disease in which endometrial-like tissue forms lesions outside the uterus. It causes infertility and severe pelvic pain in ≈176 million women worldwide, and there is currently no cure for this disease. Magnetic hyperthermia could potentially eliminate widespread endometriotic lesions but has not previously been considered for treatment because conventional magnetic nanoparticles have relatively low heating efficiency and can only provide ablation temperatures (>46 °C) following direct intralesional injection. This study is the first to describe nanoparticles that enable systemically delivered magnetic hyperthermia for endometriosis treatment. When subjected to an alternating magnetic field (AMF), these hexagonal iron-oxide nanoparticles exhibit extraordinary heating efficiency that is 6.4× greater than their spherical counterparts. Modifying nanoparticles with a peptide targeted to vascular endothelial growth factor receptor 2 (VEGFR-2) enhances their endometriosis specificity. Studies in mice bearing transplants of macaque endometriotic tissue reveal that, following intravenous injection at a low dose (3 mg per kg), these nanoparticles efficiently accumulate in endometriotic lesions, selectively elevate intralesional temperature above 50 °C upon exposure to external AMF, and completely eradicate them with a single treatment. These nanoparticles also demonstrate promising potential as magnetic resonance imaging (MRI) contrast agents for precise detection of endometriotic tissue before AMF application.

Impact of Postthrombotic Vein Wall Biomechanics on Luminal Flow during Venous Angioplasty and Stent Placement: Computational Modeling Results.

This study characterized the impact of vein wall biomechanics on inflow diameter and luminal flow during venous angioplasty and stent placement, using postthrombotic and healthy biomechanical properties from an ovine venous stenosis and thrombosis model. Finite element analysis demonstrated more pronounced inflow channel narrowing in the postthrombotic vein compared with the healthy control vein during angioplasty and stent placement (relative inflow diameter reduction of 42% versus 13%, P < .0001). Computational fluid dynamics modeling showed increased relative areas of low wall shear rate in the postthrombotic vein compared with the normal vein (0.46 vs 0.24 for shear rate < 50 s-1; 0.13 vs 0.07 for shear rate < 15 s-1; P < .05), with flow stagnation and recirculation. Since inflow narrowing and low wall shear rate are associated with in-stent restenosis and reintervention, these computational results based on experimentally obtained biomechanical values highlight the significance of postthrombotic venous properties in optimizing venous intervention outcomes.

Endovascular Venous Stenosis and Thrombosis Large Animal Model: Angiographic, Histological, and Biomechanical Characterizations.

PURPOSE: To characterize an ovine endovascular radiofrequency (RF) ablation-based venous stenosis and thrombosis model for studying venous biomechanics and response to intervention. MATERIALS AND METHODS: Unilateral short-segment (n = 2) or long-segment (n = 6) iliac vein stenoses were created in 8 adult sheep using an endovenous RF ablation technique. Angiographic assessment was performed at baseline, immediately after venous stenosis creation, and after 2-week (n = 6) or 3-month (n = 2) survival. Stenosed iliac veins and the contralateral healthy controls were harvested for histological and biomechanical assessment. RESULTS: At follow-up, the short-segment RF ablation group showed stable stenosis without occlusion. The long-segment group showed complete venous occlusion/thrombosis with the formation of collateral veins. Stenosed veins showed significant wall thickening (0.28 vs 0.16 mm, P = .0175) and confluent collagen deposition compared with the healthy controls. Subacute nonadherent thrombi were apparent at 2 weeks, which were replaced by fibrous luminal obliteration with channels of recanalization at 3 months. Stenosed veins demonstrated increased longitudinal stiffness (448.5 ± 5.4 vs 314.6 ± 1.5 kPa, P < .0001) and decreased circumferential stiffness (140.8 ± 2.6 vs 246.0 ± 1.6 kPa, P < .0001) compared with the healthy controls. CONCLUSION: Endovenous RF ablation is a reliable technique for creating venous stenosis and thrombosis in a large animal model with histological and biomechanical attributes similar to those seen in humans. This platform can facilitate understanding of venous biomechanics and testing of venous-specific devices and interventions.

Lower-Extremity Edema Is Common after Transjugular Intrahepatic Portosystemic Shunt Creation and Is Associated with Lower Survival: A Two-Institution Study.

Background Transjugular intrahepatic portosystemic shunt (TIPS) creation is an accepted treatment of portal hypertension. Lower-extremity edema (LEE) is an underreported complication of TIPS creation. Purpose To assess the epidemiologic findings of LEE after TIPS creation and their association with patient survival. Materials and Methods The medical records of patients who underwent TIPS creation between January 2003 and April 2019 at Oregon Health and Science University and patients who underwent TIPS creation between January 2006 and December 2016 at University of Minnesota were retrospectively reviewed. Clinical, laboratory, and technical parameters, development and outcome of edema, and survival data were collected. LEE was defined as new-onset or worsened edema up to 1 year after TIPS creation. Cardiac ventricular function was evaluated with transthoracic echocardiography. Risk factors for LEE were evaluated with logistic regression analysis, and critical P values were additionally assessed by using the false discovery rate. Survival curves were compared by using the log-rank test. Results Three hundred thirty-four patients were included (mean age, 55 years ± 11 [standard deviation]; 208 men). TIPS creation was primarily performed for ascites (159 of 334 patients, 48%), gastrointestinal bleeding (127 of 334 patients, 38%), or a combination of bleeding and ascites (38 of 334 patients, 11%). One hundred seventy of the 334 patients (51%) developed LEE (new onset, 120; worsened edema, 50). Three of 170 patients (2%) had abnormal left ventricular ejection fraction. Multivariable analysis showed TIPS creation for ascites (odds ratio, 1.7; 95% CI: 1.04, 2.7; P = .03) and hepatic hydrothorax (odds ratio, 2.2; 95% CI: 1.1, 4.2; P = .02) was likely associated with LEE; however, it did not reach significance at a critical P value of .009. Among 164 patients with data on the outcome of LEE, LEE eventually improved in 94 (57%). The median survival of patients with LEE was lower than that of patients without LEE (38 months vs 71 months, respectively; P = .02). Conclusion Lower-extremity edema developed in more than 50% of study patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) creation, regardless of left ventricular function. There was suggestion that TIPS creation for ascites might be an underlying risk factor. Lower-extremity edema portends worse survival. © RSNA, 2020 Online supplemental material is available for this article.

Analysis of Costs and Payments for Inferior Vena Cava Filter Retrieval in the Medicare Population.

Over the past decade, inferior vena cava (IVC) filter retrieval has been increasing, in part due to Food and Drug Administration recommendations and legal pressure. The costs and margin of IVC filter removal are poorly understood. Medicare claims data from 2016 for the 103 highest volume centers for IVC filter retrieval were examined. Pooled mean charges, costs, payments, and margin were calculated by institution. Mean ± SD charges, costs, and payments were $14,138.00 ± $8,400.48, $3,693.28 ± $2,294.27, and $1,949.82 ± $702.91, respectively. Average (range) margin was -$1,706.18 (-$7,509.93 to $362.77). The margin was negative in 99 of the 103 (96%) institutions evaluated. The most significant contributors to the total procedure cost were operating room, supplies, and recovery (44.5%, 23.5%, and 10.4%, respectively). While IVC filter retrieval is often medically indicated, it is typically associated with a financial loss under current reimbursement structure.

Embolic Characteristics of Imipenem-Cilastatin Particles in Vitro and in Vivo: Implications for Transarterial Embolization in Joint Arthropathies.

PURPOSE: To elucidate in vitro and in vivo characteristics and embolic properties of imipenem-cilastatin (IPM-CS) compared with hydrogel microspheres. MATERIALS AND METHODS: Particle size distribution was microscopically evaluated with 3 samples of 50 mg IPM-CS suspensions in each of 6 conditions by a mixture of contrast volume: 500 or 1000 µL and vortex mixing time: 5, 10, or 30 s. Time-dependent changes up to 3 h post-mixing were also evaluated. Fifteen male Sprague-Dawley rats (460.2 ± 5.0 g) underwent unilateral renal artery embolization using IPM-CS (n = 11) or hydrogel microspheres (n = 4). Follow-up angiography 48 h after embolization and histological evaluation, including acute tubular necrosis (ATN) and inflammation, were scored using a 5-point scale (from 0 = normal to 4 = severe). RESULTS: Over 91% of IPM-CS particles were <40 µm under all in vitro conditions. With the increased contrast volume, the average particle size also increased (mean ± standard deviation: 11.6 ± 13.9 vs 16.7 ± 18.2 µm for 500 and 1000 µL iodinated contrast, P < .001); however, the impact of the mixing/elapsed time were limited. At 48 h after embolization, all cases in the IPM-CS groups (11/11) showed major to complete recanalization versus no recanalization with hydrogel microspheres (0/4) (P < .001). The following are the median ATN and inflammation grades in the cortex (ventral/dorsal) and medulla (ventral/dorsal) in both groups: IPM-CS, ATN in cortex (2/4) and medulla (1/1), inflammation in cortex (0/0) and medulla (0/0); hydrogel microspheres, ATN in cortex (4/4) and medulla (3/2), inflammation in cortex (1/1) and medulla (1/1). CONCLUSIONS: IPM-CS suspension generated particles that were predominantly smaller than 40 µm and with unique short-term embolic effects, leaving predominantly peripheral ischemic changes.

Thermal Ablation Versus Stereotactic Body Radiotherapy After Transarterial Chemoembolization for Inoperable Hepatocellular Carcinoma: A Propensity Score-Weighted Analysis.

BACKGROUND. Transarterial chemoembolization (TACE) has synergistic properties when combined with ablative therapies for hepatocellular carcinoma (HCC). OBJECTIVE. The purpose of our study was to compare outcomes for inoperable HCC between TACE with percutaneous thermal ablation (TACE-TA) and TACE with stereotactic body radiotherapy (TACE-SBRT) using propensity score-weighted cohorts. METHODS. This retrospective study included 190 patients with a single inoperable HCC treated from 2007 to 2018 by either TACE-SBRT (n = 90) or TACE-TA (n = 100). The primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS) and hepatotoxicity (defined as Child-Pugh score elevation of ≥ 2 within 2-6 months after treatment). Fine-Gray competing risk models with propensity score weighting and transplant as the competing risk factor were used to model OS and PFS. RESULTS. The median follow-up time was 48.2 months. Both OS and PFS were significantly higher for TACE-TA (77% and 76%, respectively, at 2 years) than TACE-SBRT (49% and 50%, respectively, at 2 years) in the propensity score-weighted multivariate model (OS: subdistribution hazard ratio [sHR] = 2.70, p < .001; PFS: sHR = 1.71, p = .02). Treatment-related hepatotoxicity occurred in 9% of patients who underwent TACE-TA versus 27% of those who underwent TACE-SBRT (p = .01). For the subset of patients with Barcelona Clinic Liver Cancer A HCC and Child-Pugh A cirrhosis (TACE-SBRT, n = 36 patients; TACE-TA, n = 55 patients), OS (p = .11) and PFS (p = .19) were not significantly different between the two treatment modalities. CONCLUSION. Compared with TACE-SBRT, TACE-TA showed superior OS and PFS, possibly from its lesser hepatotoxicity. The two strategies did not differ in OS and PFS for patients with the earliest-stage HCC and preserved liver function. CLINICAL IMPACT. Across all patients, TACE-TA may be superior to TACE-SBRT for inoperable HCC.

Biodegradable Hypericin-Containing Nanoparticles for Necrosis Targeting and Fluorescence Imaging.

Necrosis targeting and imaging has significant implications for evaluating tumor growth, therapeutic response, and delivery of therapeutics to perinecrotic tumor zones. Hypericin is a hydrophobic molecule with high necrosis affinity and fluorescence imaging properties. To date, the safe and effective delivery of hypericin to areas of necrosis in vivo remains a challenge because of its incompatible biophysical properties. To address this issue, we have developed a biodegradable nanoparticle (Hyp-NP) for delivery of hypericin to tumors for necrosis targeting and fluorescence imaging. The nanoparticle was developed using methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) and hypericin by a modified solvent evaporation technique. The size of Hyp-NP was 19.0 ± 1.8 nm from cryo-TEM and 37.3 ± 0.7 nm from dynamic light-scattering analysis with a polydispersity index of 0.15 ± 0.01. The encapsulation efficiency of hypericin was 95.05% w/w by UV-vis absorption. After storage for 30 days, 91.4% hypericin was retained in Hyp-NP with nearly no change in hydrodynamic size, representing nanoparticle stability. In an ovarian cancer cell line, Hyp-NP demonstrated cellular internalization with intracellular cytoplasmic localization and preserved fluorescence and necrosis affinity. In a mouse subcutaneous tumor model, tumor accumulation was noted at 8 h postinjection, with near-complete clearance at 96 h postinjection. Hyp-NP was shown to be tightly localized within necrotic tumor zones. Histological analysis of harvested organs demonstrated no gross abnormalities, and in vitro, no hemolysis was observed. This proof-of-concept study demonstrates the potential clinical applications of Hyp-NP for necrosis targeting.

Prevalence of Musculoskeletal Symptoms in Interventional Radiologists.

PURPOSE: To investigate the prevalence of musculoskeletal symptoms, defined as aches, pains, discomfort, or numbness, by using a validated assessment tool among interventional radiologists. MATERIALS AND METHODS: A Web-based survey using the Nordic Musculoskeletal Questionnaire was disseminated to interventional radiologist members by email in November 2015. Musculoskeletal symptoms were evaluated in 9 body areas. Information regarding participant demographics, practice details, use of radio-protective equipment, and exercise routines was also gathered. Univariate and multivariate analyses were performed to determine risk factors associated with more severe symptoms. RESULTS: Of 4,096 SIR members at the time of the survey, 640 completed the questionnaire in its entirety (16% response rate). Respondents consisted of 69 females (11%) and 571 males (89%), with a mean age of 47.5 ± 10.2 years old, a mean body mass index of 25.5 ± 3.9 kg/m2, and a mean practice length of 17.1 ± 9.8 years. Prevalence of musculoskeletal symptoms was 88% in the 12 months preceding the survey. For those reporting musculoskeletal issues, 58% attributed the symptoms to work-related activities. Lower back (61%), neck (56%), and shoulder complaints (46%) were the most common. Symptoms prevented 21.2% of respondents from being able to work over the same time period. Multivariate analysis identified female gender, above-normal body mass index, and a practice length of 10 years or more as factors associated with a higher risk of moderate-to-severe symptoms. CONCLUSIONS: Musculoskeletal symptoms are prevalent among interventional radiologists, the majority of which are attributed to work-related causes.

Transjugular Intrahepatic Portosystemic Shunt Creation Using a Radiofrequency Wire: Acute Feasibility Study in Swine.

The feasibility of a radiofrequency (RF) wire to replace the needle trocar for the creation of a transjugular intrahepatic portosystemic shunt (TIPS) was assessed in 3 swine by using fluoroscopy and intravascular ultrasonography (IVUS). RF wire passes were successful from hepatic to portal vein and from inferior vena cava to portal vein. Technical success was achieved using both IVUS guidance and carbon dioxide portography. The wire tracked a straight course under RF energy application without subjective deflection and, when centrally advanced, served as the working wire for completing the TIPS in 2 attempts with stent graft deployment. No procedural adverse events from the use of RF wire were observed.

Venous Biomechanics of Angioplasty and Stent Placement: Implications of the Poisson Effect.

PURPOSE: To characterize the Poisson effect in response to angioplasty and stent placement in veins and identify potential implications for guiding future venous-specific device design. MATERIALS AND METHODS: In vivo angioplasty and stent placement were performed in 3 adult swine by using an established venous stenosis model. Iron particle endothelium labeling was performed for real-time fluoroscopic tracking of the vessel wall during intervention. A finite-element computational model of a vessel was created with ADINA software (version 9.5) with arterial and venous biomechanical properties obtained from the literature to compare the response to radial expansion. RESULTS: In vivo angioplasty and stent placement in a venous stenosis animal model with iron particle endothelium labeling demonstrated longitudinal foreshortening that correlated with distance from the center of the balloon (R2 = 0.87) as well as adjacent segment narrowing that correlated with the increase in diameter of the treated stenotic segment (R2 = 0.89). Finite-element computational analysis demonstrated increased Poisson effect in veins relative to arteries (linear regression coefficient slope comparison, arterial slope 0.033, R2 = 0.9789; venous slope 0.204, R2 = 0.9975; P < .0001) as a result of greater longitudinal Young modulus in veins compared with arteries. CONCLUSIONS: Clinically observed adjacent segment narrowing during venous angioplasty and stent placement is a result of the Poisson effect, with redistribution of radially applied force to the longitudinal direction. The Poisson effect is increased in veins relative to arteries as a result of unique venous biomechanical properties, which may be relevant to consider in the design of future venous interventional devices.

Effectiveness of Thermal Ablation for Aldosterone-Producing Adrenal Adenoma: A Systematic Review and Meta-Analysis of Clinical and Biochemical Parameters.

PURPOSE: To assess the effectiveness of thermal ablation for aldosterone-producing adrenal adenoma. MATERIALS AND METHODS: A systematic search of the PubMed and CINAHL databases was performed to identify studies of thermal ablation for adrenal adenomas. Random effects meta-analysis models were used to compare pre- and post-treatment values of the following outcomes: systolic blood pressure (SBP), diastolic blood pressure (DBP), use of antihypertensive medications, and biochemical parameters (plasma aldosterone levels, aldosterone-to-renin ratio, and potassium levels). The rate of hypertension (HTN) resolution and improvement were also evaluated. RESULTS: A total of 89 patients from 7 studies were included in the analysis. The mean postablation follow-up duration was 45.8 months. Pooled data analysis revealed a statistically significant decrease in SBP (-29.06 mm Hg; 95% confidence interval [CI], -33.93 to -24.19), DBP (-16.03 mm Hg; 95% CI, -18.33 to -13.73), and the number of antihypertensive medications used (-1.43; 95% CI, -1.97 to -0.89) after ablation. Biochemical parameters had returned to normal ranges after ablation in all studies. The cumulative rate of resolution or improvement in HTN status was 75.3%. On metaregression analysis, there was no statistically significant association between postablation blood pressure changes or serum aldosterone levels and study follow-up duration. CONCLUSIONS: Thermal ablation for aldosterone-producing adrenal adenoma can be effective in controlling blood pressure, reducing the need for antihypertensive medications, and normalizing hormone secretion. Further higher-quality evidence is needed to confirm these results.

Muscle Gain after Transjugular Intrahepatic Portosystemic Shunt Creation: Time Course and Prognostic Implications for Survival in Cirrhosis.

PURPOSE: To examine the association of transjugular intrahepatic portosystemic shunt (TIPS) creation with muscle gains and patient mortality, and to identify the timeframe of these changes. MATERIALS AND METHODS: Patients with cirrhosis undergoing TIPS creation with available abdominal computed tomography before and after TIPS from 2004-2015 were included (n = 76). The primary indications for TIPS included refractory ascites (52.6%) or variceal bleeding (47.4%). Axial truncal muscle area and attenuation were measured at the L4 level using free-hand region of interest technique, and pre- and post-TIPS values were compared. The association of TIPS-related muscle changes with mortality was evaluated using Cox multiple regression. Logistic regression analysis was performed to evaluate associations of baseline muscle area and clinical variables with post-TIPS changes. RESULTS: TIPS creation was associated with significant increases in psoas, paraspinal, and total muscle areas (P < .001, 0.004, and 0.002), and psoas muscle attenuation (P = .022) at a median of 13.5 months after TIPS. Maximal muscle gains occurred within 6 months after TIPS creation (P < .001). Muscle gain at 1-year after TIPS was independently associated with lower mortality (psoas hazard ratio [HR] 0.14, P = .016; paraspinal HR 0.15, P = .016; abdominal HR 0.05, P = .005; core HR 0.06, P = .001; and total HR 0.05, P = .003). Baseline demographic or clinical variables were not associated with muscle gain after TIPS. CONCLUSIONS: TIPS creation was strongly associated with truncal muscle gains and attenuation in patients with cirrhosis. Maximal muscle gain occurred within 6 months after TIPS creation. TIPS-related increased muscle mass was independently associated with lower patient mortality.

Palmar Warming for Radial Artery Vasodilation to Facilitate Transradial Access: A Randomized Controlled Trial.

PURPOSE: To investigate the efficacy of palmar warming to induce radial artery vasodilation. MATERIALS AND METHODS: After informed consent was obtained, healthy volunteers (n = 45) were randomized 2:1 in palmar warming and control groups, respectively, for this prospective, randomized, single-blind clinical trial (NCT03620383). The palmar warming group was given a warm, commercially available, air-activated heat pack (Kobayashi Consumer Products LLC, Dalton, Georgia) to hold in the left hand for palmar warming. The control group was given a deactivated version of the same heat pack. Left radial artery cross-sectional area (CSA) measurements were obtained at baseline and in 5-minute intervals up to 20 minutes in both groups. Differences in the trends of changes in the radial artery CSA between palmar warming and control groups were examined with the age- and sex-adjusted repeated measure analysis of variance. Propensity score-matched treatment effect analysis was conducted to quantify the effect of heat on radial artery CSA. RESULTS: The palmar warming group and the control group were significantly different in terms of subject sex (males/females: 7/23 and 10/5, respectively; P = .005) and baseline CSA (2.5±0.2 mm2 vs 3.2±0.3 mm2, respectively; P = .014). Radial artery CSA showed an increasing trend over time in the palmar warming group compared to a stable trend over time in the control group (P < .0001). Propensity score-matched comparison showed a 43.9% increase (95% confidence interval: 34.1%-53.8%) in CSA in the palmar warming group compared to the control group (P < .0001). CONCLUSIONS: The palmar warming technique is effective at dilating the radial artery and may be a beneficial technique to facilitate transradial access.

Transarterial Delivery of a Biodegradable Single-Agent Theranostic Nanoprobe for Liver Tumor Imaging and Combinatorial Phototherapy.

PURPOSE: To assess selective accumulation of biodegradable nanoparticles within hepatic tumors after transarterial delivery for in vivo localization and combinatorial phototherapy. MATERIALS AND METHODS: A VX2 hepatic tumor model was used in New Zealand white rabbits. Transarterial delivery of silicon naphthalocyanine biodegradable nanoparticles was performed using a microcatheter via the proper hepatic artery. Tumors were exposed via laparotomy, and nanoparticles were observed by near-infrared (NIR) fluorescence imaging. For phototherapy, a handheld NIR laser (785 nm) at 0.6 W/cm2 was used to expose tumor or background liver, and tissue temperatures were assessed with a fiberoptic temperature probe. Intratumoral reactive oxygen species formation was assessed using a fluorophore (2',7'-dichlorodihydrofluorescein diacetate). RESULTS: Nanoparticles selectively accumulated within viable tumor by NIR fluorescence. Necrotic portions of tumor did not accumulate nanoparticles, consistent with a vascular distribution. NIR-dependent heat generation was observed with nanoparticle-containing tumors, but not in background liver. No heat was generated in the absence of NIR laser light. Reactive oxygen species were formed in nanoparticle-containing tumors exposed to NIR laser light, but not in background liver treated with NIR laser or in tumors in the absence of NIR light. CONCLUSIONS: Biodegradable nanoparticle delivery to liver tumors from a transarterial approach enabled selective in vivo tumor imaging and combinatorial phototherapy.

Early Venous Stent Failure Predicted by Platelet Count and Neutrophil/Lymphocyte Ratio.

BACKGROUND: Inflammation and platelet activation have been shown to be involved in acute thromobogenicity following venous occlusive conditions. The aim of this study was to identify the association of baseline platelet count and neutrophil/lymphocyte ratio (NLR) with venous stent failure. Methods and Results: Patients who underwent technically successful iliocaval venous stent placement with available baseline complete blood count and follow-up stent patency data were selected (n=50). Stent failure was defined as >50% stenosis or occlusion at follow-up angiography, contrast-enhanced CT, MRI or duplex US. Median patient age was 49.5 years (range, 13-76 years), and 62% were female. Median follow-up time was 10.2 months (range, 0.1-76.4 months). Stent failure occurred in 13 patients (26%) after a median of 1.2 months (range, 1 day-76.4 months). On multivariable-adjusted Cox modeling, baseline platelets (HR, 2.28; P=0.004) and WBC count (HR, 2.03; P=0.013) were significantly associated with stent failure on follow-up; neutrophils (HR, 16.10; P=0.050); and NLR (HR, 12.19; P=0.050) had borderline significance. Compared with patients without stent failure, those with early, but not late, stent failure had higher baseline platelets (P=0.031) and neutrophils (P=0.025), and NLR (P=0.026). CONCLUSIONS: Baseline platelet count and NLR are associated with early but not late failure of iliocaval venous stents. This suggests different pathophysiologic mechanisms and a role for both platelet activation and inflammatory mechanisms in early rather than late stent thrombosis. Future research is needed to better explain this novel finding.