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.

Effect of systemic insulin treatment on diabetic wound healing

This study investigates if different diabetic treatment regimens affect diabetic foot ulcer healing. From January 2013 to December 2014, 107 diabetic foot ulcers in 85 patients were followed until wound healing, amputation or development of a nonhealing ulcer at the last follow-up visit. Demographic data, diabetic treatment regimens, presence of peripheral vascular disease, wound characteristics, and outcome were collected. Nonhealing wound was defined as major or minor amputation or those who did not have complete healing until the last observation. Median age was 60.0 years (range: 31.1-90.1 years) and 58 cases (68.2%) were males. Twenty-four cases reached a complete healing (healing rate: 22.4%). The median follow-up period in subjects with classified as having chronic wounds was 6.0 months (range: 0.7-21.8 months). Insulin treatment was a part of diabetes management in 52 (61.2%) cases. Insulin therapy significantly increased the wound healing rate (30.3% [20/66 ulcers] vs. 9.8% [4/41 ulcers]) (p = 0.013). In multivariate random-effect logistic regression model, adjusting for age, gender, smoking status, type of diabetes, hypertension, chronic kidney disease, peripheral arterial disease, oral hypoglycemic use, wound infection, involved side, presence of Charcot's deformity, gangrene, osteomyelitis on x-ray, and serum hemoglobin A1C levels, insulin treatment was associated with a higher chance of complete healing (beta ± SE: 15.2 ± 6.1, p = 0.013). Systemic insulin treatment can improve wound healing in diabetic ulcers after adjusting for multiple confounding covariates.

Predictive value of neutrophil-to-lymphocyte ratio in diabetic wound healing

OBJECTIVE

The neutrophil-to-lymphocyte ratio (NLR) has been used as a surrogate marker of systemic inflammation. We sought to investigate the association between NLR and wound healing in diabetic wounds.

METHODS

The outcomes of 120 diabetic foot ulcers in 101 patients referred from August 2011 to December 2014 were examined retrospectively. Demographic, patient-specific, and wound-specific variables as well as NLR at baseline visit were assessed. Outcomes were classified as ulcer healing, minor amputation, major amputation, and chronic ulcer.

RESULTS

The subjects' mean age was 59.4 ± 13.0 years, and 67 (66%) were male. Final outcome was complete healing in 24 ulcers (20%), minor amputation in 58 (48%) and major amputation in 16 (13%), and 22 chronic ulcers (18%) at the last follow-up (median follow-up time, 6.8 months). In multivariate analysis, higher NLR (odds ratio, 13.61; P = .01) was associated with higher odds of nonhealing.

CONCLUSIONS

NLR can predict odds of complete healing in diabetic foot ulcers independent of wound infection and other factors.

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.

Characterization of Iodide-induced Sialadenitis: Meta-analysis of the Published Case Reports in the Medical Literature

PURPOSE

To evaluate the patient presentation of postcontrast sialadenitis and factors associated with its duration of symptoms through meta-analysis of case reports.

BACKGROUND

Acute iodide sialadenitis, or "iodide mumps," is a rare adverse reaction to iodinated contrast causing salivary gland swelling. The condition may be underdiagnosed, with researchers postulating that its true incidence may be close to 1-2%.

METHODS AND MATERIALS

This study was a meta-analysis performed using PRISMA Reporting Standards. A literature search with no language restriction was performed of the Medline database, primarily through PubMed, using keywords: "iodide mumps," "iodide sialadenitis," "sialadenitis," "salivary enlargement," "contrast reaction," "parotid swelling," and "submandibular swelling." Matching case reports and case series were reviewed, and data regarding the subjects' demographics, renal function, contrast administration, and symptoms were extracted. Uni- and multivariate linear regression analyses were applied to assess the predicting factors of a prolonged symptoms duration.

RESULTS

Sixty-five case reports and case series were identified, with 77 cases of iodide-induced sialadenitis. Two cases were unpublished and from the author's institution. Reported subjects' median age was 63 years, and 61% (47/77) were males. Median time to onset was 16 hours, and symptoms resolved in a median of 3 days after the initial onset. Twenty-seven subjects (35%, 27/77) were reported to have an impaired renal function at baseline. Administration of nonionic, low osmolarity contrast medium was reported most frequently (53%, 41/77). There was no difference in resolution of symptoms among subjects with impaired versus normal renal function. Symptoms were resolved in all cases over a median of 3 days with no statistically significant difference between those who received therapeutic intervention and those who did not (p = 0.430). Older age and longer time to onset were significantly associated with longer duration of symptoms in both uni- and multivariate linear regression models, and presence of tenderness demonstrated statistical significance associated with longer duration of symptoms in the univariate model.

CONCLUSION

Postcontrast sialadenitis is a rare reaction to iodinated contrast media. Older age and a longer time to onset of symptoms are associated with longer duration of symptoms.

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.

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.

Correlation of serum alkaline phosphatase with clinicopathological characteristics of patients with oesophageal cancer

Oesophageal cancer is endemic in some regions of the Islamic Republic of Iran and efforts have made to find factors that play a role in its prognosis. We retrospectively examined the correlation of serum alkaline phosphatase (ALP) levels with several clinicopathological characteristics of 207 cases of oesophageal carcinoma. The mean ALP level in patients with lymph node involvement was significantly higher [141 (SD 77) U/L] than with node negative cancers [116 (SD 63) U/L]. Patients with ALP levels 165 U/L were 3.29 times more likely to have lymph node involvement than patients with ALP levels < or = 165 U/L. There was no statistically significant correlation between ALP level and sex, age, tumour histological type, site and size of tumour, depth of penetration, distant metastasis, degree of differentiation, presence of lymphatic invasion and presence of simultaneous multiple cancers. Elevated ALP in patients with oesophageal cancer may predict lymph node involvement.

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.

Risk factors for stent graft thrombosis after transjugular intrahepatic portosystemic shunt creation

Background

To identify risk factors of stent graft thrombosis after transjugular intrahepatic portosystemic shunt (TIPS) creation.

Methods

Patients who underwent TIPS creation between June 2003 and January 2016 and with follow-up assessing stent graft patency were included (n=174). Baseline comorbidities, liver function, procedural details and follow-up liver function tests were analyzed in association with hazards of thrombosis on follow-up. Competing risk cox regression models were used considering liver transplant after TIPS creation as the competing risk variable.

Results

One-, 2- and 5-year primary patency rates were 94.1%, 91.7% and 78.2%, respectively. Patient age [sub-hazard ratio (sHR): 1.13; P=0.001], body mass index (BMI) <30 (sHR: 33.08; P=0.008) and a higher post-TIPS portosystemic pressure gradient (sHR: 1.14; P=0.023) were significantly associated with TIPS thrombosis in multivariate analysis. A higher rate of TIPS thrombosis was observed in those for whom the procedure was clinically unsuccessful (P=0.014). A significant increase in incidence of thrombosis was noted with increasing tertiles of post-TIPS portosystemic gradients (P value for trend=0.017).

Conclusions

Older age, lower BMI and higher post-TIPS portosystemic gradients were associated with higher hazards of shunt thrombosis after TIPS creation using stent grafts. Higher rates of shunt thrombosis were seen in patients for whom TIPS creation was clinically unsuccessful. The association between TIPS thrombosis and higher post-TIPS portosystemic gradients may indicate impaired flow through the shunt, a finding which may be technical or anatomic in nature and should be assessed before procedure completion.

Endovascular Treatment of Tracheoinnominate Artery Fistula: Case Report and Literature Review With Pooled Cohort Analysis

To pool data from published cases of tracheoinnominate artery fistula (TIF) treated with surgical or endovascular techniques along with reporting a case of similar presentation. A total of 261 cases in 137 published case reports and case series were identified through a comprehensive systematic literature review. Data regarding patient characteristics, treatment, and follow-up were extracted. A local case of a 14-year-old boy with TIF due to longstanding tracheostomy treated with stent-graft placement was added to the data. Comparison of the complication rates between surgical vs endovascular interventions was done with the chi-square test. Factors associated with longer survival were assessed by the Cox regression analysis. Thirty-three (12.6%) of the reported cases were treated endovascularly, 137 (52.3%) were treated surgically, and 92 (35.1%) were reported with no definitive treatment. Mean age was 34 ± 22 years, and 61% were males. The mean time interval between tracheotomy placement and bleeding was 1 ± 2.5 years. A lower procedure-related complication (30% vs 50%, P = 0.045) and 30-day mortality (9% vs 23%, P = 0.008) rates had been reported with percutaneous approaches compared to surgery. No percutaneous procedure was reported prior to year 2000. In multivariate analysis stratified by publication year, a shorter tracheostomy-to-bleeding time (year) was significantly associated with higher hazards of death (hazard ratio: 1.22, P = 0.017). Type of intervention (percutaneous vs surgery) was not associated with postintervention survival (adjusted hazard ratio: 0.78, P = 0.558). Endovascular stent grafting can have a comparable postprocedural survival and lower complication rates vs open surgical repair in treatment of TIF.

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.

Percutaneous renal artery revascularization after prolonged ischemia secondary to blunt trauma: pooled cohort analysis

PURPOSE

We aimed to identify factors related to technical and clinical success of percutaneous revascularization for blunt renal arterial trauma.

METHODS

All cases of percutaneous revascularization for blunt renal arterial trauma were searched in the available literature. We included a case of iatrogenic renal artery occlusion at our institution treated by percutaneous stenting 20 hours after injury. A pooled cohort analysis of percutaneous revascularization for blunt renal artery injury was then performed to analyze factors related to technical and clinical success. Clinical failure was defined as development of new hypertension, serum creatinine rise, or significant asymmetry in split renal function.

RESULTS

A total of 53 cases have been reported, and 54 cases were analyzed including our case. Median follow-up was 6 months. Technical success was 88.9% and clinical success was 75%. Of 12 treatment failures (25%), 66.7% occurred during the first postprocedure month. Time from injury to revascularization was not a predictor of clinical success (OR=1.00, P = 0.681). Renal artery occlusion was significantly associated with clinical failure (OR=7.50, P = 0.017) and postintervention antiplatelet therapy was significantly associated with treatment success (OR=0.16, P = 0.043). At 37-month follow-up, the stented renal artery in our case remained patent and the patient was normotensive with preserved glomerular filtration rate.

CONCLUSION

Percutaneous revascularization for blunt renal arterial injury resulted in relatively high technical and clinical success. Time-to-revascularization was independent of successful outcomes. Clinical success was significantly associated with a patent renal artery at the time of intervention and with postprocedure antiplatelet therapy.

Treatment of pulmonary arteriovenous malformations: clinical experience using different embolization strategies

PURPOSE

To evaluate embolization efficacy of pulmonary arteriovenous malformations (PAVM) using Amplatzer vascular plugs (AVP) and coils.

MATERIALS AND METHODS

Eighty-eight embolized simple PAVMs in 38 patients were retrospectively analyzed by follow-up CT. Mean age was 50.2 ± 15.6 years and 22 (57.9%) patients were females. Mean follow-up interval was 38.2 ± 28.4 months (median 29.9 months). Embolization devices included AVP I, AVP II, AVP 4, and coils. Technical success was defined as no visualization of an early draining vein at angiography after embolization. Treatment success was defined as complete disappearance or decrease in size of the venous aneurysm ≥ 70% at follow-up CT.

RESULTS

Technical success rate was 100% and treatment success rate evaluated by CT for the various embolization strategies was 100% for AVP I (n = 6), 100% for AVP I + coils (n = 5), 83.3% for AVP II (n = 6), 40.0% for AVP II + coils (n = 5), 87.5% for AVP 4 (n = 8), 50.0% for AVP 4 + coils (n = 8), and 78.0% for coils alone (n = 50). No statistically significant difference in embolization efficacy was seen between different devices (P = 0.083). Although not statistically significant, combination use of coils with AVPs demonstrated lower rates of clinical embolization success (P = 0.053).

CONCLUSION

Embolization of PAVMs demonstrated high technical and treatment success rates with available embolic devices. No significant statistical differences were demonstrated between AVPs. However, the need for both coils and AVPs may suggest a more complicated underlying lesion at risk for recurrence.

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.

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.

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.

Combination therapy with TACE + ablation versus TACE + SBRT for hepatocellular carcinoma (HCC): Comparative analysis with propensity score-weighted cohorts

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Background: To assess the relative efficacy and toxicity associated with TACE+Ablation (Ablation) or TACE+SBRT (SBRT) in a large cohort of patients with unresectable HCC. Methods: Patients with HCC undergoing Ablation or SBRT from 2006-2016 with available follow up were included. Treatment groups were different at baseline regarding tumor stage (BCLC A, B and C: 96%, 4%, 0% (Ablation) vs. 73%, 14% and 13% (SBRT), P < 0.001) and severity of liver disease (CTP A, B, and C: 55%, 45% and 0% (Ablation) vs. 50%, 41%, and 9% (SBRT), P = 0.007). Propensity scores were calculated with age, sex, BCLC stage, CTP class, etiology of liver disease, tumor number, and diameter to balance the cohorts. Average treatment effects on survival with multivariable propensity score-weighted competing risk Cox regression models were evaluated, with BCLC stage, number of treated tumors and liver transplant as additionally controlled variables. Primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), local tumor control and hepatotoxicity. Treatment-related hepatotoxicity was defined as a two point change in CTP within six months after treatment. Results: 192 subjects were included (101 Ablation, 91 SBRT; median age=60 years, 75% men). Liver disease included HCV (78%), alcohol (35%) and NASH (8%). Liver transplant-adjusted 1- and 2-year OS rates were significantly greater for Ablation vs SBRT (88% vs. 75% and 77% vs. 50%, P<0.001). 1-and 2-year PFS rates were significantly greater for Ablation vs. SBRT (84% vs. 65% and 75% vs. 51%, P < 0.001). 1- and 2- year local tumor control rates were similar with both strategies (99% vs. 91% and 94% vs. 87%, P=0.298). Propensity score-weighted multivariable analysis showed significantly higher OS (sHR: 2.31, P = 0.006) and PFS rates (sHR:1.75, P = 0.008) with Ablation compared to SBRT. Ablation was also associated with lower post-treatment hepatotoxicity compared with SBRT (5% vs. 12%, P = 0.001). Conclusions: TACE+Ablation demonstrated higher OS/PFS and lower post-treatment hepatotoxicity compared with TACE+SBRT. Local disease control up to two years was equivocal, potentially suggesting equipoise for bridge to transplant.

A novel multimodal nanoplatform for targeting tumor necrosis

Peri-necrotic tumor regions have been found to be a source of cancer stem cells (CSC), important in tumor recurrence. Necrotic and peri-necrotic tumor zones have poor vascular supply, limiting effective exposure to systemically administered therapeutics. Therefore, there is a critical need to develop agents that can effectively target these relatively protected tumor areas. We have developed a multi-property nanoplatform with necrosis avidity, fluorescence imaging and X-ray tracking capabilities to evaluate its feasibility for therapeutic drug delivery. The developed nanoparticle consists of three elements: poly(ethylene glycol)-block-poly(ε-caprolactone) as the biodegradable carrier; hypericin as a natural compound with fluorescence and necrosis avidity; and gold nanoparticles for X-ray tracking. This reproducible nanoparticle has a hydrodynamic size of 103.9 ± 1.7 nm with a uniform spherical morphology (polydispersity index = 0.12). The nanoparticle shows safety with systemic administration and a stable 30 day profile. Intravenous nanoparticle injection into a subcutaneous tumor-bearing mouse and intra-arterial nanoparticle injection into rabbits bearing VX2 orthotopic liver tumors resulted in fluorescence and X-ray attenuation within the tumors. In addition, ex vivo and histological analysis confirmed the accumulation of hypericin and gold in areas of necrosis and peri-necrosis. This nanoplatform, therefore, has the potential to enhance putative therapeutic drug delivery to necrotic and peri-necrotic areas, and may also have an application for monitoring early response to anti-tumor therapies.

Au-Hyp-NP developed by encapsulation of gold and hypericin into PEG-PCL nanoplatform for fluorescence and X-ray tracking with tumor necrosis targeting.

Endovascular Venous Stenosis and Thrombosis Large Animal Model: angiographic, histological, and biomechanical characterization

PURPOSE

Characterize an ovine endovascular radiofrequency 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 eight adult sheep using an endovenous radiofrequency (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 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 formation of collateral veins. Stenosed veins showed significant wall thickening (0.28 mm vs 0.16 mm; p = 0.0175) and confluent collagen deposition compared to healthy controls. Subacute non-adherent 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 kPa vs. 314.6 ± 1.5 kPa, p < 0.0001) and decreased circumferential stiffness (140.8 ± 2.6 kPa vs. 246.0 ± 1.6 kPa, p < 0.0001) compared to healthy controls.

CONCLUSION

Endovenous radiofrequency 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.