Outcomes in Enteral Access Based on Specialty and Approach: A Single-Center Three-Year Experience.

INTRODUCTION: Interventional radiologic, endoscopic, and surgical approaches are commonly utilized to establish durable enteral access in adult patients. The purpose of this study is to examine differences in nutritional outcomes in a large cohort of patients undergoing enteral access creation. METHODS: Adult patients who underwent enteral access procedures by interventional radiologists, gastroenterologists, and surgeons between 2018 and 2020 at a single institution were reviewed. Included access types were percutaneous endoscopic gastrostomy (PEG), open or laparoscopic gastrostomy, laparoscopic jejunostomy, and percutaneous gastrostomy (perc-G), percutaneous jejunostomy , or primary gastrojejunostomy. RESULTS: 912 patients undergoing enteral access cases met the criteria for inclusion. PEGs and perc-Gs were the most common procedures. PEGs had higher Charlson scores (4.5 [3.0-6.0] versus 2.0 [1.0-2.0], P = 0.007) and lower starting albumin (3.0 [2.6-3.4] versus 3.6 [3.5-3.8] g/dL, P < 0.0001). Time to goal feeds (4 [2-6] vs 4 [3-5] d, P = 0.970), delta prealbumin (3.6 [0-6.5] versus 6.2 [2.3-10] mg/L, P = 0.145), time to access removal (160 [60-220] versus 180 [90-300] d, P = 0.998), and enteral access-related complications (19% versus 16%, P = 0.21) between PEG and perc-G were similar and differences were not statistically significant. A greater percent change in prealbumin was noted for perc-G (10 [-3-20] versus 41.7% [11-65], P = 0.002). CONCLUSIONS: Despite having higher Charlson scores and worse preoperative nutrition, there is a similar incidence of enteral access-related complications, time to goal feeds, delta prealbumin, or time to access removal between PEG and perc-G patients. Our data suggest that access approach should be made on an individual basis, accounting for anatomy and technical feasibility.

Intranodal Glue Embolization for Postoperative Lymphatic Leaks in the Groin and Pelvis: Comparison with Sclerotherapy.

PURPOSE: To compare the effectiveness of and adverse events related to intranodal glue embolization (IGE) with those of intracavitary sclerotherapy for the treatment of postoperative groin and pelvic lymphatic leaks. MATERIALS AND METHODS: From November 2015 to July 2021, IGE for postoperative pelvic or groin lymphocele or lymphorrhea was performed in 33 patients. From January 2010 to July 2021, 28 patients with postoperative pelvic or groin lymphocele were treated with sclerosis alone. Clinical success was defined as resolution of drainage within 3 weeks of the last intervention performed without recurrence. Patients presenting >1 year after surgery or with <30 days of follow-up were excluded. Patients with lymphorrhea treated with IGE were not statistically compared with those in the sclerosis group because they were not eligible for sclerosis. RESULTS: Clinical success was similar between the groups (lymphocele IGE, 15/18, 83.3%, vs sclerosis, 15/23, 65.2% [P = .29]; lymphorrhea IGE, 8/9, 88.9%). The mean number of interventions performed to successfully treat a lymphocele was significantly higher in the sclerosis group (2.5 for sclerosis vs 1.3 for IGE; P = .003; lymphorrhea IGE, 1.0). The mean time to resolution was significantly longer for sclerosis than for IGE (27 vs 7 days; P = .002; 4 days for lymphorrhea IGE). There were no sclerosis-related adverse events and 2 IGE-related adverse events: (a) 1 case of mild lymphedema and (b) 1 case of nontarget embolization resulting in deep vein thrombosis. CONCLUSIONS: For treatment of postoperative pelvic and groin lymphoceles, IGE results in faster resolution with fewer interventions compared with sclerosis. IGE is also an effective treatment for postoperative groin lymphorrhea.

Outcomes following Exchange and Upsizing of Malfunctioning Small-Caliber Double-J Ureteral Stents.

PURPOSE: To determine the effectiveness of exchange and upsizing of malfunctioning small-caliber double-J (JJ) ureteral stents. MATERIALS AND METHODS: Thirty-one patients with malfunctioning cystoscopically placed small-caliber (6 or 7 F) JJ stents underwent transurethral (n = 28) or transrenal (n = 3) exchange and upsizing to a large-caliber (10 F) JJ stent from 2013 to 2022. Ureteral obstruction was malignant in 20 patients (65%) and benign in 11 (35%). Fifteen patients (48%) presented with persistent hydroureteronephrosis and 16 patients (52%) with worsening hydronephrosis. Acute kidney injury (AKI) was present in 19 patients (61%) at the time of stent malfunction. Therapeutic success was defined as resolution of hydronephrosis and AKI, if present. RESULTS: JJ stent exchange and upsizing was technically successful in 31 patients (100%) with no immediate adverse events. Therapeutic success was achieved in 27 patients (87%). During follow-up (median, 97 days; IQR, 32-205 days), 2 patients who initially achieved therapeutic success had stent malfunction, requiring conversion to percutaneous nephrostomy drainage (2/27, 7%). CONCLUSIONS: Exchange and upsizing to large-caliber JJ stents can relieve urinary obstruction and resolve AKI in patients with malfunctioning small-caliber JJ stents. Large-caliber JJ stents should be considered as a salvage option for patients who wish to continue internal drainage and avoid percutaneous nephrostomy.

Mitigation of Sarcopenia after Peritoneovenous Shunt Placement in Patients with Refractory Ascites.

PURPOSE: To evaluate the effect of peritoneonvenous shunt placement on metrics of sarcopenia in patients with refractory ascites. MATERIALS AND METHODS: An institutional review board-approved single-institution retrospective analysis of all patients who underwent peritoneovenous shunt (Denver Shunt; BD, Franklin Lakes, New Jersey) placement (N = 29) and a comparator cohort of patients with cirrhosis who underwent serial paracentesis (N = 42) from 2009 to 2019 with baseline and follow-up cross-sectional imaging of at least 3 months was performed. Axial muscle area measurements (psoas, paraspinal, and total abdominal wall) were performed using free-hand region-of-interest technique. Patient records were reviewed for demographic characteristics, referring indication, laboratory studies, and performance status. Statistical analyses were performed with Student t test, Welch unequal variances, Fisher exact test, and Wilcoxon signed rank test. RESULTS: The most common indications for peritoneovenous shunt placement were metastatic disease or cirrhosis. In the shunt cohort, there were no significant differences in the aggregate psoas muscle area (13.4 vs 14.0 cm2; P = .223) or paraspinal muscle area (43.0 vs 42.2 cm2; P = .471). In the paracentesis cohort, there were significant decreases in aggregate psoas (18.1 vs 15.7 cm2; P < .0001) and erector spinae (43.4 vs 39.9 cm2; P < .0001) muscle area. In addition, there was a significant decrease in serum albumin level (3.2 vs 3.0 g/dL; P = .015) and Eastern Cooperative Oncology Group performance status score (1.0 vs 1.3; P < .0001) in the paracentesis group, compared with no significant changes in the shunt cohort. CONCLUSIONS: In patients with refractory ascites who are not candidates for transjugular intrahepatic portosystemic shunt placement, peritoneovenous shunt mitigates loss of truncal muscle and, in some instances, promotes muscle growth.

Iatrogenic Renal Artery Injury in 90 Cases: Arteriographic Findings and Outcomes after Embolization for Bleeding.

PURPOSE: To evaluate differences in arteriographic findings and outcomes after embolization among patients with a suspected iatrogenic renal arterial injury (IRAI). MATERIALS AND METHODS: Patients at the authors' institution who underwent renal arteriography for suspected IRAIs after partial nephrectomy, biopsy, or percutaneous access over a 20-year period were included. Records, imaging, and outcomes were reviewed. Data analysis was performed using the Fisher exact or Kruskal-Wallis test. RESULTS: Ninety arteriograms were performed on 83 patients after partial nephrectomy (n = 32), biopsy (n = 27), or percutaneous access (n = 24), including for nephrostomy/ureterostomy and stone removal. The median number of days between the index procedure and arteriogram was highest (15 days) after partial nephrectomy and lowest (5 days) after biopsy (P = .0001). Embolization was performed during 76% of arteriograms. If prearteriographic imaging showed positive results for IRAIs, embolization was performed in 67% versus 33% if imaging showed negative results (P = .005). The transfusion rate was higher after biopsy than after partial nephrectomy or percutaneous access (P = .002). Acute kidney injury after arteriogram occurred in 7% of patients; however, all returned to baseline by 1 week. CONCLUSIONS: Despite the different mechanism of IRAIs in partial nephrectomy, biopsy, and percutaneous access, arteriographic findings and outcomes were overall similar among groups. Prearteriographic imaging can help identify IRAIs but cannot supersede the clinical judgment regarding indication for embolization. IRAIs can present acutely or after a long interim, although patients who underwent biopsy presented earlier and more frequently required a blood transfusion. IRAIs can be treated with embolization without permanent deleterious effects on renal function.

A 5-Year Update on the IR Residency Match: 2022 National Survey Results of Program Directors and Matched Applicants Compared with 2017.

PURPOSE: To characterize the experiences of matched applicants (MAs) and program directors (PDs) in the 2022 interventional radiology (IR) residency Match and compare with 2017 data. METHODS: Surveys were distributed to IR PDs and MAs from the 2022 Match. Findings were compared with those of 2017 using the 2-sample t test and Fisher exact test. RESULTS: In total, 68 MAs (40%) and 47 PDs (52%) responded. Collected demographic traits were similar, including ongoing male predominance (77% of MAs, 83% of PDs). Moreover, 86% of MAs and 87% of PDs were "satisfied" with Match outcomes. Compared with those in 2017, MAs applied to more IR programs (P < .001). MAs reported more research (P = .003) and abstracts/publications (P < .001) and ranked these as more important than PDs did (P < .001 for both). Approximately 82% of PDs gave special attention to candidates who completed a visiting rotation at their institution; 60% of MAs and 95% of PDs believed virtual interviews resulted in overinterviewing (P < .001); both agreed they provided convenience and accessibility. Furthermore, 63% of MAs believed a Step 1 pass/fail system will be less equitable for applicants. Additional data on demographics, medical school experiences, applications, interviews, intern year, and rank process were reported. CONCLUSIONS: Satisfaction with Match results remained high from 2017 to 2022, although efforts are needed to improve applicants' ability to navigate the application process, address overapplying, and evaluate concerns regarding the Step 1 pass/fail system. These survey findings will help inform applicants and PDs for future match cycles.

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.

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.

Radiologically Placed Peritoneovenous Shunt is an Acceptable Treatment Alternative for Refractory Ascites Due to End-Stage Liver Disease.

PURPOSE: To compare patients treated with large-volume paracentesis (LVP), transjugular intrahepatic portosystemic shunt (TIPS), and peritoneovenous shunt (PVS) for ascites. MATERIALS AND METHODS: A retrospective study of 192 patients treated with LVP (94), TIPS (75), or PVS (23) was performed. Records were reviewed for patient characteristics and outcomes. The patients' age differed (LVP, 59.5 years; TIPS, 58.8 years; and PVS, 65.6 years; P = .003). Nonalcoholic steatohepatitis was the most common etiology in the PVS cohort (11/23, 47%), and hepatitis C in the TIPS (27/75, 36%), and LVP cohorts (43/94, 46%) (P = .032). The model for end-stage liver disease score was significantly different (LVP, 14; TIPS, 13; and PVS, 8; P = .035). Hepatocellular carcinoma was higher in the PVS cohort (6/23 patients, 25%) than in the TIPS (4/75, 5%), and LVP (12/94, 12%) cohorts (P = .03). RESULTS: Emergency department visits and hospital readmissions were the highest in the LVP cohort (40%, ≥2 readmissions, P < .001). Patients required fewer LVPs after TIPS (1.5 to 0.14, P < .001) or PVS (2.1 to 0.5, P = .019). In an unadjusted Cox model, patients in the TIPS cohort were found to have a 58% reduction in the risk of death compared with patients in the LVP cohort (P = .003). Transplant-free survival (PVS, 44 days; TIPS, 155 days; and LVP, 213 days) differed (log rank = 0.001). CONCLUSIONS: The survival in the PVS and TIPS cohorts was similar, with less healthcare utilization than the LVP cohort. PVS is a satisfactory alternative to LVP.

Infection Rates Following Hepatic Embolotherapy in Patients with Prior Biliary Interventions: Comparison of Single-Drug Moxifloxacin and Multidrug Antibiotic Prophylaxis.

PURPOSE: To investigate the incidence of infection in patients with prior biliary interventions undergoing hepatic embolotherapy following extended antibiotic prophylaxis using moxifloxacin monotherapy or a multidrug regimen. MATERIAL AND METHODS: Under an Institutional Review Board-approved protocol, retrospective review of a quality assurance database identified all liver-directed therapies (LDTs) at a tertiary care center between 2010 and 2019 with biliary intervention prior to LDT Records were reviewed for infectious complications within 3 months of chemo- or radioembolization. Patients were categorized based on extended antibiotic prophylaxis regimen: oral moxifloxacin monotherapy or multidrug regimen of levofloxacin and metroniodazole plus preprocedural neomycin and erythromycin. Procedures without at least 2 months of clinical follow-up, hepatic ablation, and procedures without extended antibiotic prophylaxis were excluded Regression analysis was used to analyze multivariate data to detect a difference in infection rate. RESULTS: Twenty-four chemoembolization and 58 radioembolization procedures were performed on 55 patients with prior biliary interventions. Forty-four used monotherapy and 38 used multidrug regimen. The incidence of infection was 16.7% (4/24) after chemoembolization and 13.8% (8/58) after radioembolization The incidence of infection in patients did not differ between antibiotic prophylaxis regimens (18.2% [8/44] with moxifloxacin monotherapy and 10.5% [4/38] multidrug regimen, P = .3) or between types of biliary interventions (24.1% [7/29] with bilioenteric anastomosis and 23.8% [5/21] biliary stenting, P = .3). CONCLUSIONS: The types of extended antibiotic prophylaxis (moxifloxacin monotherapy vs multitherapy), prior biliary intervention, and embolotherapy were not found to be associated with differences in the incidence of infectious complications in this population.

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.

Diagnosis and Treatment of Nonmaturing Fistulae for Hemodialysis Access via Transradial Approach: A Case-Control Study.

PURPOSE: To compare outcomes of transradial access for endovascular treatment of nonmaturing hemodialysis fistulae compared to brachial arteriography followed by unidirectional or bidirectional fistula access for intervention. MATERIALS AND METHODS: In this institutional review board-approved, retrospective, case-control study, 56 consecutive patients with nonmaturing arteriovenous fistulae underwent percutaneous intervention between 2015 and 2018. The transradial group (n = 28) underwent radial artery access for diagnostic fistulography and intervention. The control group (n = 28) underwent retrograde brachial artery access for fistulography followed by unidirectional/bidirectional fistula access for intervention. Both groups had similar demographics, fistula characteristics, and stenosis locations. RESULTS: Fewer punctures were required in the transradial group compared to controls (1.2 vs 2.4, P < .0001), and procedure time was shorter (64.9 vs 91.3 minutes, P = .0016). Anatomic, technical, and clinical success rates trended higher in the transradial group compared to controls (93% vs 86%, 96% vs 89%, and 82% vs 64%, respectively). Nonmaturation resulting in fistula abandonment was lower in the transradial group (3.7% vs 25%, P = .025). Primary unassisted patency at 3, 6, and 12 months was 77.1% ± 8.2%, 73.1% ± 8.7%, and 53.3% ± 10.6% in the transradial group, respectively, and 63.0% ± 9.3%, 55.6% ± 9.6%, and 48.1% ± 9.6% in the control group, respectively (P = .76). Primary assisted patency at 12 months was 92.3% ± 5.3% in the transradial group compared to 61.8% ± 9.6% at 12 months in the control group (P = .021). No major complications occurred. Minor complications were lower in the transradial group than in the control group (14% vs 39%, P = .068). CONCLUSIONS: Treatment of nonmaturing fistulae via a transradial approach was safe, improved midterm patency, and was associated with lower rates of fistula abandonment.

Comparison of Clinical Performance of VectorFlow and Palindrome Symmetric-Tip Dialysis Catheters: A Multicenter, Randomized Trial.

PURPOSE: To compare clinical performance of 2 widely used symmetric-tip hemodialysis catheters. MATERIALS AND METHODS: Patients with end-stage renal disease initiating or resuming hemodialysis were randomized to receive an Arrow-Clark VectorFlow (n = 50) or Palindrome catheter (n = 50). Primary outcome was 90-d primary unassisted catheter patency. Secondary outcomes were Kt/V ([dialyzer urea clearance × total treatment time]/total volume of urea distribution), urea reduction ratio (URR), and effective blood flow (QB). RESULTS: Primary unassisted patency rates with the VectorFlow catheter at 30, 60, and 90 d were 95.5% ± 3.3, 87.2% ± 7.3, and 80.6% ± 9.8, respectively, compared with 89.1% ± 6.2, 79.4% ± 10.0, and 71.5% ± 12.6 with the Palindrome catheter (P = .20). Patients with VectorFlow catheters had a mean Kt/V of 1.5 at 30-, 60-, and 90-day time points, significantly higher than the mean Kt/V of 1.3 among those with Palindrome catheters (P = .0003). URRs were not significantly different between catheters. Catheter QB rates exceeded National Kidney Foundation-recommended thresholds of 300 mL/min at all time points for both catheters and were similar for both catheters (median, 373 mL/min). Catheter failure, ie, poor flow rate requiring guide-wire exchange or removal, within the 90-day primary outcome occurred in 3 VectorFlow subjects and 5 Palindrome subjects (P = .72). Infection rates were similar, with 0.98 infections per 1,000 catheter days for VectorFlow catheters compared with 2.62 per 1,000 catheter days for Palindrome catheters (P = .44). CONCLUSIONS: The 90-day primary patency rates of Palindrome and VectorFlow catheters were not significantly different, and both achieved sustained high QB through 90 day follow-up. However, dialysis adequacy based on Kt/V was consistently better with the VectorFlow catheter versus the Palindrome.

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.

Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography and Percutaneous Lymphatic Embolization for the Diagnosis and Treatment of Recurrent Chyloptysis.

Chyloptysis, or the expectoration of triglyceride-rich sputum, is rare and typically treated with diet modification and thoracic duct ligation. This article describes 2 patients with prolonged histories of chyloptysis who failed conservative treatment and thoracic duct ligation. Dynamic contrast-enhanced magnetic resonance imaging delineated the lymphatic anatomy and identified the abnormal pulmonary lymphatic perfusion pathways in both patients. This imaging provided guidance for successful percutaneous lymphatic embolization which resulted in resolution of symptoms in both patients.

Radioembolization-Induced Chronic Hepatotoxicity: A Single-Center Cohort Analysis.

PURPOSE: To identify and characterize the delayed effects of transarterial radioembolization (TARE) on the liver. MATERIALS AND METHODS: A single-institution retrospective analysis was undertaken of all patients who received TARE between 2005 and 2014 and survived at least 1 year from the initial TARE (n = 106). Patients were evaluated for the presence or absence of radioembolization-induced chronic hepatotoxicity (RECHT) occurring at least 6 months after TARE. The mean age of patients was 63 years of age, and the malignancy most commonly treated was neuroendocrine tumor (54%). Adjudication of hepatic decompensation to RECHT versus alternative causes was performed by a multidisciplinary panel of specialists from hepatology, radiation oncology, and interventional radiology. RESULTS: Eight patients were excluded from analysis because of liver transplantation (2) or incomplete data (6). RECHT occurred in 13 of 98 patients (13%), and 5 deaths (5%) occurred from hepatic decompensation. There were a total of 69 toxicity events in patients developing RECHT. The most common events were elevation of alkaline phosphatase (10), decrease in serum albumin (10), and development of ascites (9). RECHT patients had a higher intrahepatic tumor volume (P = .021) and a higher number of hepatic comorbidities leading to cirrhosis (P = .015). CONCLUSIONS: Delayed radiation-induced hepatic toxicity occurred in 13% of patients following radioembolization, with 5 fatalities adjudicated to be a result of the treatment. Tumor involvement of greater than 50% of the liver and cirrhosis were predisposing factors for RECHT.

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.