Outcomes of Transarterial Embolization for Acute Nonvariceal Upper Gastrointestinal Bleeding: Correlation with Periprocedural Endoscopy.

PURPOSE: To evaluate gastric and intestinal mucosal changes on postembolic endoscopy and mortality after transarterial embolization (TAE) for upper gastrointestinal bleeding (UGIB). MATERIALS AND METHODS: An institutional review board-approved retrospective review of patients who underwent arteriography for refractory UGIB at a multicenter health system from December 2003 to August 2019 was performed. Two hundred sixty-nine patients underwent TAE for UGIB. Data on etiology of bleeding, embolization technique, pre-embolic and postembolic endoscopic results, blood product requirements, and mortality were collected from the medical record. Endoscopy results were compared at the site of the target lesion before and after TAE. Multivariable logistic regressions were performed to assess predictors of new adverse mucosal responses and mortality. RESULTS: The most common etiology of UGIB was peptic ulcer. Twenty-five percent (n = 68) of the patients had clinical evidence of rebleeding after TAE, and the 30-day mortality rate was 26% (n = 73). Eighty-eight (32%) patients underwent post-TAE endoscopy, with only 15% showing new adverse mucosal changes after embolization. Procedural characteristics, including vascular territory and embolic choice, were not significantly predictive of increased risk of development of adverse mucosal response after TAE or increased mortality risk. No patients in the study were found to have bowel lumen stenosis at the time of post-TAE endoscopy or at 6 year follow-up. CONCLUSIONS: TAE is a safe and effective intervention for patients with UGIB. Post-TAE endoscopy demonstrated that most patients had either stability or improvement in the target lesion after TAE, and only a minority of patients demonstrated adverse mucosal changes.

Transarterial Embolization Modulates the Immune Response within Target and Nontarget Hepatocellular Carcinomas in a Rat Model.

Background Transarterial embolization (TAE) is the most common treatment for hepatocellular carcinoma (HCC); however, there remain limited data describing the influence of TAE on the tumor immune microenvironment. Purpose To characterize TAE-induced modulation of the tumor immune microenvironment in a rat model of HCC and identify factors that modulate this response. Materials and Methods TAE was performed on autochthonous HCCs induced in rats with use of diethylnitrosamine. CD3, CD4, CD8, and FOXP3 lymphocytes, as well as programmed cell death protein ligand-1 (PD-L1) expression, were examined in three cohorts: tumors from rats that did not undergo embolization (control), embolized tumors (target), and nonembolized tumors from rats that had a different target tumor embolized (nontarget). Differences in immune cell recruitment associated with embolic agent type (tris-acryl gelatin microspheres [TAGM] vs hydrogel embolics) and vascular location were examined in rat and human tissues. A generalized estimating equation model and t, Mann-Whitney U, and χ2 tests were used to compare groups. Results Cirrhosis-induced alterations in CD8, CD4, and CD25/CD4 lymphocytes were partially normalized following TAE (CD8: 38.4%, CD4: 57.6%, and CD25/CD4: 21.1% in embolized liver vs 47.7% [P = .02], 47.0% [P = .01], and 34.9% [P = .03], respectively, in cirrhotic liver [36.1%, 59.6%, and 4.6% in normal liver]). Embolized tumors had a greater number of CD3, CD4, and CD8 tumor-infiltrating lymphocytes relative to controls (191.4 cells/mm2 vs 106.7 cells/mm2 [P = .03]; 127.8 cells/mm2 vs 53.8 cells/mm2 [P < .001]; and 131.4 cells/mm2 vs 78.3 cells/mm2 [P = .01]) as well as a higher PD-L1 expression score (4.1 au vs 1.9 au [P < .001]). A greater number of CD3, CD4, and CD8 lymphocytes were found near TAGM versus hydrogel embolics (4.1 vs 2.0 [P = .003]; 3.7 vs 2.0 [P = .01]; and 2.2 vs 1.1 [P = .03], respectively). The number of lymphocytes adjacent to embolics differed based on vascular location (17.9 extravascular CD68+ peri-TAGM cells vs 7.0 intravascular [P < .001]; 6.4 extravascular CD68+ peri-hydrogel embolic cells vs 3.4 intravascular [P < .001]). Conclusion Transarterial embolization-induced dynamic alterations of the tumor immune microenvironment are influenced by underlying liver disease, embolic agent type, and vascular location. © RSNA, 2022 Online supplemental material is available for this article. See also the editorials by Kennedy et al and by White in this issue.

Preintervention Computed Tomography Improves the Performance of Endovascular Intervention in Patients with Abdominopelvic Trauma.

PURPOSE: To evaluate the role of computed tomography (CT) and CT angiography in guiding endovascular arteriography (EA) and embolization in hemodynamically (HD) stable and unstable patients with abdominal and/or pelvic (AP) trauma. MATERIALS AND METHODS: A retrospective review was performed of patients with AP trauma who underwent EA with or without embolization (from January 2012 to August 2020) at an urban, level I trauma center. Patients aged <18 years or those undergoing EA outside of the abdomen and/or pelvis were excluded. Demographics, imaging findings, procedure length, contrast agent administration, laboratory values, and outcomes were compared on the basis of preprocedural imaging technique and hemodynamic status. RESULTS: A total of 190 patients with AP trauma underwent EA with or without embolization; among them, 123 were HD stable and underwent CT/CT angiography, whereas 67 were initially HD unstable and underwent operative management prior to EA. Of these patients, 38 underwent CT/CT angiography after hemodynamic stability was achieved prior to postoperative EA. The incidence of therapeutic embolization for arterial injury on EA was significantly higher in patients with preprocedural CT/CT angiography (65.8% vs 44.8%, P = .04). The positive and negative predictive values of CT angiography for arterial injury at the time of EA were 92.3% and 100%, respectively. Prior imaging was associated with a reduced contrast agent requirement at the time of EA and reduced transfusion requirement (P = .05 and P = .02). No significant differences were observed in adverse outcomes for patients undergoing preprocedural imaging. CONCLUSIONS: CT or CT angiography prior to EA for HD stable and unstable patients with AP trauma may improve the likelihood of therapeutic embolization and enable improved procedure metrics without increasing adverse outcomes.

Multicenter assessment of augmented reality registration methods for image-guided interventions.

PURPOSE: To evaluate manual and automatic registration times and registration accuracies on HoloLens 2 for aligning a 3D CT phantom model onto a CT grid, a crucial step for intuitive 3D navigation during CT-guided interventions; to compare registration times between HoloLens 1 and 2. METHODS: Eighteen participants in various stages of clinical training across two academic centers performed registration of a 3D CT phantom model onto a CT grid using HoloLens 2. Registration times and accuracies were compared among different registration methods, clinical experience levels, and consecutive attempts. Registration times were also compared retrospectively to prior HoloLens 1 results. RESULTS: Mean aggregate manual registration times were 27.7 s, 24.3 s, and 72.8 s for one-handed gesture, two-handed gesture, and Xbox controller, respectively; mean automatic registration time was 5.3 s (ANOVA p < 0.0001). No significant difference in registration times was found among attendings, residents and fellows, and medical students (p > 0.05). Significant improvements in registration times were detected across consecutive attempts using hand gestures (p < 0.01). Compared to prior HoloLens 1 data, hand gesture registration was 81.7% faster with HoloLens 2 (p < 0.05). Registration accuracies were not significantly different across manual registration methods, measuring at 5.9 mm, 9.5 mm, and 8.6 mm with one-handed gesture, two-handed gesture, and Xbox controller, respectively (p > 0.05). CONCLUSIONS: Manual registration times decreased significantly on HoloLens 2, approaching those of automatic registration and outperforming Xbox controller registration. Fast, adaptive, and accurate registration of holographic models of cross-sectional imaging is paramount for the implementation of augmented reality-assisted 3D navigation during CT-guided interventions.

Neurology and the histiocytoses: a case of Rosai-Dorfman-Destombes disease.

The histiocytoses are a group of rare disorders characterised by the accumulation of neoplastic or non-neoplastic activated histiocytes in various tissues. Phenotypes vary widely from cutaneous lesions or lymphadenopathy that regress spontaneously to disseminated disease with poor prognosis. Neurological symptoms can be a presenting feature or appear during the course of disease. We present a challenging diagnostic and management case of Rosai-Dorfman-Destombes disease in a 48-year-old woman with a relapsing, partially steroid-responsive syndrome comprising patchy, non-length-dependent radiculoneuropathy with diffuse pachymeningitis and widespread systemic disease, and recent dramatic response to novel mitogen-activated kinase pathway inhibition. We discuss the clinical characteristics, diagnosis, recent breakthroughs in pathogenesis and emerging treatment options for Rosai-Dorfman disease and for the histiocytoses with neurological sequelae, including Langerhans cell histiocytosis and Erdheim-Chester disease.

Hyperpolarized Metabolic Imaging Detects Latent Hepatocellular Carcinoma Domains Surviving Locoregional Therapy.

BACKGROUND AND AIMS: Advances in cancer treatment have improved survival; however, local recurrence and metastatic disease-the principal causes of cancer mortality-have limited the ability to achieve durable remissions. Local recurrences arise from latent tumor cells that survive therapy and are often not detectable by conventional clinical imaging techniques. Local recurrence after transarterial embolization (TAE) of hepatocellular carcinoma (HCC) provides a compelling clinical correlate of this phenomenon. In response to TAE-induced ischemia, HCC cells adapt their growth program to effect a latent phenotype that precedes local recurrence. APPROACH AND RESULTS: In this study, we characterized and leveraged the metabolic reprogramming demonstrated by latent HCC cells in response to TAE-induced ischemia to enable their detection in vivo using dynamic nuclear polarization (DNP) magnetic resonance spectroscopic imaging (MRSI) of 13 carbon-labeled substrates. Under TAE-induced ischemia, latent HCC cells demonstrated reduced metabolism and developed a dependence on glycolytic flux to lactate. Despite the hypometabolic state of these cells, DNP-MRSI of 1-13 C-pyruvate and its downstream metabolites, 1-13 C-lactate and 1-13 C-alanine, predicted histological viability. CONCLUSIONS: These studies provide a paradigm for imaging latent, treatment-refractory cancer cells, suggesting that DNP-MRSI provides a technology for this application.

Augmented and Mixed Reality: Technologies for Enhancing the Future of IR.

Augmented and mixed reality are emerging interactive and display technologies. These technologies are able to merge virtual objects, in either 2 or 3 dimensions, with the real world. Image guidance is the cornerstone of interventional radiology. With augmented or mixed reality, medical imaging can be more readily accessible or displayed in actual 3-dimensional space during procedures to enhance guidance, at times when this information is most needed. In this review, the current state of these technologies is addressed followed by a fundamental overview of their inner workings and challenges with 3-dimensional visualization. Finally, current and potential future applications in interventional radiology are highlighted.

Three-Dimensional Augmented Reality Visualization Informs Locoregional Therapy in a Translational Model of Hepatocellular Carcinoma.

PURPOSE: To evaluate the utility of visualizing preprocedural MR images in 3-dimensional (3D) space using augmented reality (AR) before transarterial embolization of hepatocellular carcinoma (HCC) in a preclinical model. MATERIALS AND METHODS: A total of 28 rats with diethylnitrosamine-induced HCCs > 5 mm treated with embolization were included in a prospective study. In 12 rats, 3D AR visualization of preprocedural MR images was performed before embolization. Procedural metrics including catheterization time and radiation exposure were compared vs a prospective cohort of 16 rats in which embolization was performed without AR. An additional cohort of 15 retrospective cases was identified and combined with the prospective control cohort (n = 31) to improve statistical power. RESULTS: A 37% reduction in fluoroscopy time, from 11.7 min to 7.4 minutes, was observed with AR when compared prospectively, which did not reach statistical significance (P = .12); however, when compared with combined prospective and retrospective controls, the reduction in fluoroscopy time from 14.1 min to 7.4 minutes (48%) was significant (P = .01). A 27% reduction in total catheterization time, from 42.7 minutes to 31.0 minutes, was also observed with AR when compared prospectively, which did not reach statistical significance (P = .11). No significant differences were seen in dose-area product or air kerma prospectively. CONCLUSIONS: Three-dimensional AR visualization of preprocedural imaging may aid in the reduction of procedural metrics in a preclinical model of transarterial embolization. These data support the need for further studies to evaluate the potential of AR in endovascular oncologic interventions.

MR Imaging Enables Real-Time Monitoring of In Vitro Electrolytic Ablation of Hepatocellular Carcinoma.

PURPOSE: To evaluate the capability of T2-weighted magnetic resonance (MR) imaging to monitor electrolytic ablation-induced cell death in real time. MATERIALS AND METHODS: Agarose phantoms arranged as an electrolytic cell were exposed to varying quantities of electric charge under constant current to create a pH series. The pH phantoms were subjected to T2-weighted imaging with region of interest quantitation of the acquired signal intensity. Subsequently, hepatocellular carcinoma (HCC) cells encapsulated in an agarose gel matrix were subjected to 10 V of electrolytic ablation for variable lengths of time with and without concurrent T2-weighted MR imaging. Cellular death was confirmed by a fluorescent reporter. Finally, to confirm that real-time MR images corresponded to ablation zones, 10 V electrolytic ablations were performed followed by the addition of pH-neutralizing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer. RESULTS: Analysis of MR imaging from agarose gel pH phantoms demonstrated a relationship between signal intensity and pH at the anodes and cathodes. The steep negative phase of the anode model (pH < 3.55) and global minimum of the cathode model (pH ≈ 11.62) closely approximated established cytotoxic pH levels. T2-weighted MR imaging demonstrated a strong correlation of ablation zones with regions of HCC cell death (r = 0.986; R2 = 0.916; P < .0001). The addition of HEPES buffer to the hydrogel resulted in complete obliteration of MR imaging-observed ablation zones, confirming that change in pH directly caused the observed signal intensity attenuation of the ablation zone. CONCLUSIONS: T2-weighted MR imaging enabled the real-time detection of electrolytic ablation zones, demonstrating a strong correlation with histologic cell death.

Immunotherapy and the Interventional Oncologist: Challenges and Opportunities-A Society of Interventional Oncology White Paper.

Interventional oncology is a subspecialty field of interventional radiology that addresses the diagnosis and treatment of cancer and cancer-related problems by using targeted minimally invasive procedures performed with image guidance. Immuno-oncology is an innovative area of cancer research and practice that seeks to help the patient's own immune system fight cancer. Both interventional oncology and immuno-oncology can potentially play a pivotal role in cancer management plans when used alongside medical, surgical, and radiation oncology in the care of cancer patients.

Angiographic Atlas of the Visceral Vascular Anatomy in Translational Rat Models.

PURPOSE: To characterize angiographic and cross-sectional imaging anatomy of the rat visceral vasculature in 2 translational models. MATERIALS AND METHODS: Animal studies were conducted in accordance with institutional guidelines and approval of the Institutional Animal Care and Use Committees. Retrospective review of digital subtraction arteriography was performed in 65 Wistar and 50 Sprague-Dawley male rats through a left common carotid artery or right common femoral artery approach. MR imaging of the abdomen was performed on the rats to correlate imaging modalities. RESULTS: Aortography was performed in 3 locations, including cranial to the celiac artery, cranial to the renal arteries, and cranial to the caudal (inferior) mesenteric artery, enabling characterization of the visceral branch arteries in all 65 Wistar rats. Selective arteriography of first-, second-, and third-order branch vessels of the aorta was performed allowing characterization of normal and variant anatomy. Dedicated selective arteriography was performed of the celiac artery in 65 Wistar and 10 Sprague-Dawley rats, of the common hepatic artery in 65 Wistar and 50 Sprague-Dawley rats, and of the cranial mesenteric artery in 43 Wistar rats. MR imaging enabled correlation with the lobar and portal venous anatomy. CONCLUSIONS: Analysis of arteriography and MR imaging in these rat models will provide translational researchers with anatomic details needed to develop new endovascular protocols for small animal research in interventional radiology.

Association of Complete Radiologic and Pathologic Response following Locoregional Therapy before Liver Transplantation with Long-Term Outcomes of Hepatocellular Carcinoma: A Retrospective Study.

PURPOSE: To evaluate long-term outcomes of patients with hepatocellular carcinoma (HCC) who show a complete response (CR) vs non-CR on pretransplantation imaging studies or pathologic evaluation of liver explants after locoregional therapy (LRT) before liver transplantation. MATERIALS AND METHODS: Patients listed for liver transplantation for HCC (March 1998 to December 2010) undergoing LRT with available multiphase MR/CT imaging before transplantation were included. Pathologic response was evaluated based on liver explant pathology. A total of 108 patients (17 women; 16%) met the inclusion criteria. RESULTS: Radiologic CR was achieved in 65 patients (60%) vs non-CR in 43 (40%), and pathologic CR was achieved in 36 patients (33%) vs non-CR in 72 (67%). Mean 5-year overall survival (OS) from the time of listing and recurrence-free survival (RFS) after liver transplantation were significantly better for patients with pathologic CR vs non-CR on explant pathology (OS, 83.3% vs 65.2% [28% difference; P = .046]; RFS, 80.6% vs 62.5% [29% difference; P = .045]). Mean 5-y OS and RFS were not significantly different between patients with radiologic CR or non-CR on pretransplantation imaging (OS, 75.4% vs 65.1% [P = .12]; RFS, 74% vs 62.8% [P = .17]). CONCLUSIONS: Achievement of a pathologic CR vs non-CR in response to LRT before liver transplantation for HCC is associated with improved OS from time of listing and improved RFS after liver transplantation. However, current imaging paradigms fall short of accurate delineation of response to LRT, resulting in poor correlation of outcomes between pathologic and radiologic CR.

Changing antiepilepsy drug-prescribing trends in women with epilepsy in the UK and Ireland and the impact on major congenital malformations.

OBJECTIVES: After 20 years of data collection, pregnancy registers have informed prescribing practice. Various populations show trends for a reduction in valproate prescribing, which is associated with an increased risk of anatomical teratogenesis and neurodevelopmental effects in those exposed in utero. Our aim was to determine if any shifts in prescribing trends have occurred in the UK and Ireland Epilepsy and Pregnancy Register cohort and to assess if there had been any change in the overall major congenital malformation (MCM) rate over time. METHODS: The UK and Ireland Epilepsy and Pregnancy Register, a prospective, observational, registration and follow-up study established in 1996, was used to determine the changes in antiepileptic drugs (AEDs) utilised during pregnancy and the MCM rate between 1996 and 2016. Linear regression analysis was used to assess changes in AED utilisation, and Poisson regression was used for the analysis of trends in the MCM rates. RESULTS: Outcome data for 9247 pregnancies showed a stable percentage of monotherapy to polytherapy prescribing habits over time. After Bonferroni correction, statistically significant (p<0.003) changes were found in monotherapy prescribing with increases in lamotrigine and levetiracetam and decreases in valproate and carbamazepine use. Between 1996 and 2016, the total MCM rate showed a 2.1% reduction per year (incidence risk ratio 0.979 (95% CIs 0.956 to 1.002) but Poisson regression analysis showed that this was not statistically significant p=0.08). CONCLUSION: Significant changes are seen in the prescribing habits in this cohort over 20 years, but a statistically significant change in the MCM rate was not detected. This work should be replicated on a larger scale to determine if significant changes are occurring in the MCM rate, which would allow a robust economic estimate of the benefits of improvements in prescribing practice and the personal effect of such changes.

Near-Infrared Fluorescence Imaging of Matrix Metalloproteinase 2 Activity as a Biomarker of Vascular Remodeling in Hemodialysis Access.

PURPOSE: To establish the capability of near-infrared fluorescence (NIRF) imaging for the detection of matrix metalloproteinase 2 (MMP-2) activity as a biomarker of vascular remodeling (VR) in arteriovenous fistulae (AVFs) in vivo. MATERIALS AND METHODS: AVFs were created in the right groins of Wistar rats (n = 10), and sham procedures were performed in the contralateral groins. Fistulography via a left common carotid artery approach confirmed stenosis (> 50%) in a subset of animals (n = 5) 4 weeks after AVF creation. After administration of MMP-2-activated NIRF probe, near-infrared imaging was performed in vivo and ex vivo of both the AVF and the sham-treated vessels to measure radiant efficiency of MMP-2-activated NIRF signal over background. Histologic analyses of AVF and sham-treated vessels were performed to measure VR defined as inward growth of the vessel caused by intimal thickening. RESULTS: AVFs demonstrated a significantly higher percentage increase in radiant efficiency over background compared with sham vessels (45.5 ± 56% vs 16.1 ± 17.8%; P = .008). VR in AVFs was associated with increased thickness of neointima staining positively for MMP-2 (161.8 ± 45.5 µm vs 73.2 ± 36.7 µm; P = .01). A significant correlation was observed between MMP-2 activity as measured by relative increase in radiant efficiency for AVFs and thickness of neointima staining positively for MMP-2 (P = .039). CONCLUSIONS: NIRF imaging can detect increased MMP activity in remodeled AVFs compared with contralateral sham vessels. MMP-2-activated NIRF signal correlates with the severity of intimal thickening. These findings suggest NIRF imaging of MMP-2 may be used as a biomarker of the vascular remodeling underlying stenosis.

A self-completed questionnaire study of attitudes and perceptions of paramedic and prehospital practitioners towards acute seizure care in Northern Ireland.

INTRODUCTION: Paramedics are increasingly expected to take on wider roles in the management of epilepsy in the community by making nonconveyance decisions after patients have had seizures. Studies have identified barriers to the successful implementation of this clinical role. We sought to determine levels of confidence, training, perceived barriers, and self-identified learning needs and methods to address these needs regarding seizure management. METHODS AND MATERIALS: A questionnaire was developed by consensus and administered to 63 paramedic and prehospital clinicians at various mandatory training days occurring at the central headquarters of the regional ambulance service in Northern Ireland. Participants had no foreknowledge of the questionnaire, which was self-completed and returned immediately. RESULTS: A 75% return rate was obtained after 63 questionnaires were distributed. Paramedics had a mean of 11.5years of experiences, and 49% had treated 1-10 seizures in the last year. The Joint Royal Colleges Ambulance Liaison Committee guideline on seizure management is the most commonly utilized clinical guideline (100%). All could recall formal training on seizures in their qualification course. They identified a need to develop their knowledge in certain aspects of drug management and seizure subtype identification, including nonepileptic attack disorder (NEAD). Seventy percent of paramedics had a limited understanding of NEAD. Overall, paramedics rated their confidence as higher in drug treatment and the process of managing a seizure but rated their confidence lower in recognizing different seizure types as well as making nonconveyance decisions. The two factors which were cited as instilling high confidence included clinical experience and good use of provided protocols. Other barriers identified included lack of access to intramuscular midazolam, poor information availability in the prehospital setting, and a lack of a feedback mechanism to ensure follow-up. The methods by which learning needs would be addressed included tutorials, e-Learning, and simulation, with 30% preferring a combination of these methods. CONCLUSIONS: We identified that the paramedic workforce feels a reasonable to high level of confidence in the management of acute seizures. However, there are areas where they experience less confidence including making nonconveyance decisions and the identification of nontonic-clonic seizure subtypes.

Ischemia Induces Quiescence and Autophagy Dependence in Hepatocellular Carcinoma.

Purpose To characterize hepatocellular carcinoma (HCC) cells surviving ischemia with respect to cell cycle kinetics, chemosensitivity, and molecular dependencies that may be exploited to potentiate treatment with transarterial embolization (TAE). Materials and Methods Animal studies were performed according to institutionally approved protocols. The growth kinetics of HCC cells were studied in standard and ischemic conditions. Viability and cell cycle kinetics were measured by using flow cytometry. Cytotoxicity profiling was performed by using a colorimetric cell proliferation assay. Analyses of the Cancer Genome Atlas HCC RNA-sequencing data were performed by using Ingenuity Pathway Analysis software. Activation of molecular mediators of autophagy was measured with Western blot analysis and fluorescence microscopy. In vivo TAE was performed in a rat model of HCC with (n = 5) and without (n = 5) the autophagy inhibitor Lys05. Statistical analyses were performed by using GraphPad software. Results HCC cells survived ischemia with an up to 43% increase in the fraction of quiescent cells as compared with cells grown in standard conditions (P < .004). Neither doxorubicin nor mitomycin C potentiated the cytotoxic effects of ischemia. Gene-set analysis revealed an increase in mRNA expression of the mediators of autophagy (eg, CDKN2A, PPP2R2C, and TRAF2) in HCC as compared with normal liver. Cells surviving ischemia were autophagy dependent. Combination therapy coupling autophagy inhibition and TAE in a rat model of HCC resulted in a 21% increase in tumor necrosis compared with TAE alone (P = .044). Conclusion Ischemia induces quiescence in surviving HCC cells, resulting in a dependence on autophagy, providing a potential therapeutic target for combination therapy with TAE. © RSNA, 2017 Online supplemental material is available for this article.

Increasing Medical Student Exposure to IR through Integration of IR into the Gross Anatomy Course.

PURPOSE: To compare medical student knowledge of and interest in interventional radiology (IR) before and after the integration of an IR lecture series within the gross anatomy course. MATERIALS AND METHODS: Four elective IR lectures were scheduled to coincide with the relevant anatomy dissection curriculum. Anonymous surveys were distributed to 146 students before and after the lectures regarding students' knowledge of and interest in IR, responsibilities of an IR physician, and IR training pathways. Those who did not attend served as controls. RESULTS: Response rates were 67% (n = 98) in the prelecture group, 55% (n = 22) in the group who attended the lecture, and 28% (n = 30) in the control group. A total of 73% of the prelecture group reported little knowledge of IR compared with other specialties. This decreased to 27% in those who attended the lecture (P < .001). A total of 32% of those who attended believed they had more knowledge of IR than any other specialty, compared with 7% of controls (P value not significant) and 2% of the prelecture group (P < .001). Those in attendance could name a significantly greater number of IR procedures (mean, 1.82) than the prelecture group (mean, 0.57; P < .001). A total of 64% of those who attended would consider a career in IR, compared with 24% in the prelecture group and 33% in the control group (P < .05). A total of 68% of those who attended had knowledge of the IR residency, compared with 5% in the prelecture group and 33% in the control group (P < .05). CONCLUSIONS: Integration of IR education into the gross anatomy course proved to be a highly effective way of teaching preclinical students about IR and generating interest in the field.

Relative Initial Weight Is Associated with Improved Survival without Altering Tumor Latency in a Translational Rat Model of Diethylnitrosamine-Induced Hepatocellular Carcinoma and Transarterial Embolization.

PURPOSE: To test the hypotheses that (i) heavier rats demonstrate improved survival with diminished fibrosis in a diethylnitrosamine (DEN)-induced model of hepatocellular carcinoma (HCC) and (ii) transarterial embolization via femoral artery access decreases procedure times versus carotid access. MATERIALS AND METHODS: One hundred thirty-eight male Wistar rats ingested 0.01% DEN in water ad libitum for 12 weeks. T2-weighted magnetic resonance imaging was used for tumor surveillance. Rats underwent selective embolization of ≥ 5 mm tumors via carotid or femoral artery catheterization under fluoroscopic guidance. Rats were retrospectively categorized into 3 groups by initial weight (< 300, 300-400, > 400 g) for analyses of survival, tumor latency, and fibrosis. Access site was compared relative to procedural success, mortality, and time. RESULTS: No significant differences in tumor latency were related to weight group (P = .310). Rats weighing < 300 g had shorter survival than both heavier groups (mean, 88 vs 108 d; P < .0001), and more severe fibrosis (< 300 g median, 4.0; 300-400 g median, 1.5; > 400 g median, 1.0; P = .015). No significant difference was found in periprocedural mortality based on access site; however, procedure times were shorter via femoral approach (mean, 71 ± 23 vs 127 ± 24 min; P < .0001). CONCLUSIONS: Greater initial body weight resulted in improved survival without prolonged tumor latency for rats with DEN-induced HCCs and was associated with less severe fibrosis. A femoral approach for embolization resulted in decreased procedure time. These modifications provide a translational animal model of HCC and transarterial embolization that may be suited for short-term survival studies.

Outcomes of Percutaneous Cholecystostomy in the Presence of Ascites.

PURPOSE: To evaluate whether the presence of ascites increases complications following placement of percutaneous cholecystostomy tubes (PCTs). MATERIALS AND METHODS: Retrospective review of all transhepatic PCTs placed between January 2005 and June 2014 was performed: 255 patients were included (median age of 65 y; range, 20-95 y). Of these patients, 97 had ascites and 158 had no ascites or only pelvic fluid. In all, 115 patients had calculous cholecystitis (45%), 127 had acalculous cholecystitis (50%), and 13 had common bile duct obstruction (5%). The primary outcome of interest was all complications, including bile peritonitis, pericatheter leakage requiring PCT change, pericholecystic abscess formation, drain dislodgment, or death from biliary sepsis within 14 days of initial PCT insertion. RESULTS: The overall complication rate was 11% among patients with ascites (n = 11), compared with 10% in those without (n = 16; P = .834). No difference was found between the two groups in any one complication. The overall outcome of PCT drainage differed between groups, with significantly shorter survival times in patients with ascites. Patients with ascites underwent cholecystectomy less often than patients without ascites (21% vs 39%; P = .002). Likewise, patients with ascites were more likely than those without ascites to die with the PCT in place (49% vs 25%; P = .001). CONCLUSIONS: Frequencies of complications following PCT insertion were similar in patients with and without ascites. Additionally, the overall complication rate was low and not significantly different between the two groups. These observations support the use of PCT placement in patients with ascites.