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.

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.

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.

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.

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.

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.

Variability in biopsy quality informs translational research applications in hepatocellular carcinoma

In the era of precision medicine, biopsies are playing an increasingly central role in cancer research and treatment paradigms; however, patient outcomes and analyses of biopsy quality, as well as impact on downstream clinical and research applications, remain underreported. Herein, we report biopsy safety and quality outcomes for percutaneous core biopsies of hepatocellular carcinoma (HCC) performed as part of a prospective clinical trial. Patients with a clinical diagnosis of HCC were enrolled in a prospective cohort study for the genetic, proteomic, and metabolomic profiling of HCC at two academic medical centers from April 2016 to July 2020. Under image guidance, 18G core biopsies were obtained using coaxial technique at the time of locoregional therapy. The primary outcome was biopsy quality, defined as tumor fraction in the core biopsy. 56 HCC lesions from 50 patients underwent 60 biopsy events with a median of 8 core biopsies per procedure (interquartile range, IQR, 7–10). Malignancy was identified in 45/56 (80.4%, 4 without pathology) biopsy events, including HCC (40/56, 71.4%) and cholangiocarcinoma (CCA) or combined HCC-CCA (5/56, 8.9%). Biopsy quality was highly variable with a median of 40% tumor in each biopsy core (IQR 10–75). Only 43/56 (76.8%) and 23/56 (41.1%) samples met quality thresholds for genomic or metabolomic/proteomic profiling, respectively, requiring expansion of the clinical trial. Overall and major complication rates were 5/60 (8.3%) and 3/60 (5.0%), respectively. Despite uniform biopsy protocol, biopsy quality varied widely with up to 59% of samples to be inadequate for intended purpose. This finding has important consequences for clinical trial design and highlights the need for quality control prior to applications in which the presence of benign cell types may substantially alter findings.

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.

Demographic Trends in Female Interventional Radiology Trainees With the Advent of the Integrated Interventional Radiology Residency

OBJECTIVE

Examine changes in gender representation in the interventional radiology (IR) training pool since the advent of the integrated IR residency in 2015 to 2020.

METHODS

Electronic Residency Application Service and ACGME Data Resource Book records from 2015 to 2020 were reviewed for integrated IR residency and vascular and interventional radiology (VIR) fellowship applicant data and active IR resident and VIR fellow data, respectively. The Society of Interventional Radiology (SIR) 2018 registry data were reviewed for SIR membership data. Two-tailed Fisher's exact tests and χ² analyses were used to compare trainees between application cycles.

RESULTS

In the 2017 application cycle, 23% (247 of 1,062) of integrated IR residency applicants were female, with similar interest in the 2018, 2019, and 2020 cycles (χ²[3, n = 2,863] = 5.1, P = .17). In comparison, female VIR fellowship applicants were 12% from 2017 to 2020. Female integrated IR residents represented 13% to 18% of all integrated IR residents in the 2016 to 2020 academic years compared with the period before the integrated IR residency when female IR trainees represented 8% (23 of 275) of all IR trainees in 2015 to 2016 (P = .0002). Although in 2018, the total active SIR female membership was 9% (319 of 3,622), the female resident membership was 17% (131 of 793), and the female medical student membership was 25% (389 of 1,573).

DISCUSSION

With the advent of the integrated IR residency, there is an increasing female constituency, at the medical student, IR applicant, and IR resident levels, with more than a doubling of female IR trainees, portending a continued reduction in the IR gender disparity in the future.

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 reality improves procedural efficiency and reduces radiation dose for CT-guided lesion targeting: a phantom study using HoloLens 2

Out-of-plane lesions pose challenges for CT-guided interventions. Augmented reality (AR) headsets are capable to provide holographic 3D guidance to assist CT-guided targeting. A prospective trial was performed assessing CT-guided lesion targeting on an abdominal phantom with and without AR guidance using HoloLens 2. Eight operators performed a cumulative total of 86 needle passes. Total needle redirections, radiation dose, procedure time, and puncture rates of nontargeted lesions were compared with and without AR. Mean number of needle passes to reach the target reduced from 7.4 passes without AR to 3.4 passes with AR (p = 0.011). Mean CT dose index decreased from 28.7 mGy without AR to 16.9 mGy with AR (p = 0.009). Mean procedure time reduced from 8.93 min without AR to 4.42 min with AR (p = 0.027). Puncture rate of a nontargeted lesion decreased from 11.9% without AR (7/59 passes) to 0% with AR (0/27 passes). First needle passes were closer to the ideal target trajectory with AR versus without AR (4.6° vs 8.0° offset, respectively, p = 0.018). AR reduced variability and elevated the performance of all operators to the same level irrespective of prior clinical experience. AR guidance can provide significant improvements in procedural efficiency and radiation dose savings for targeting out-of-plane lesions.

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.

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.

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 (Q_B).

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 Q_B 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 Q_B through 90 day follow-up. However, dialysis adequacy based on Kt/V was consistently better with the VectorFlow catheter versus the Palindrome.

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.

Conventional Lymphangiography (CL) in the Management of Postoperative Lymphatic Leakage (PLL): A Systematic Review

BACKGROUND

 Postoperative lymphatic leakage (PLL) is usually managed by conservative and/or surgical treatments but these procedures can be challenging to perform and potentially clinically ineffective. Therefore, conventional lymphangiography (CL) has emerged as an important alternative. The aim of this review is to present the available outcome data on CL in the management of PLL.

METHOD

 A systematic literature search (PubMed) using the MeSH term "lymphangiography" was performed and the search was restricted to literature published between January 2007 and August 2019. Identification, screening, and assessment for eligibility and inclusion were conducted in accordance with PRISMA.

RESULTS

 From the initially obtained 1006 articles (identification), 28 articles with a total of 201 patients were finally included (inclusion). The methodological quality of all included articles corresponds to level 4 (Oxford Centre for Evidence-based Medicine - Levels of Evidence, March 2009). PLL occurs after oncological and non-oncological surgery in the form of chylothorax, chylous ascites, and cervical, thoracic, abdominal and peripheral lymph fistula and/or lymphocele. The technical success rate of CL is 75-100 %. Access for CL is transpedal (176 patients) or intranodal (25 patients). Lipiodol is used as the contrast material in all articles, with a maximum amount of 20 ml for transpedal CL and 30 ml for intranodal CL. The X-ray imaging modalities used for CL are fluoroscopy, radiography and/or CT. Two articles report CL-associated major complications and CL-associated morbidity and mortality. The PLL cure rate is 51-70 % for transpedal CL (time to PLL cure: 2-29 days) and 33-100 % for intranodal CL (time to PLL cure: 2-< 30 days). Bailout procedures in the case of clinically ineffective CL include a range of treatments.

CONCLUSION

 CL is feasible, safe, and effective in the management of PLL. Lipiodol as the contrast material is essential in CL because the highly viscous iodinated poppy-seed oil has not only diagnostic but therapeutic effects. Guidelines and randomized controlled trials are further steps towards defining the ultimate value of CL.

KEY POINTS

  · PLL is a difficult-to-treat and potentially life-threatening surgical complication.. · CL has emerged as an alternative to conservative/surgical treatment of PLL.. · CL is feasible, safe, and effective in the management of PLL. · Lipiodol-based CL can be regarded as a therapeutic procedure.. · Guidelines and randomized controlled trials are further important steps..

CITATION FORMAT

· Sommer CM, Pieper CC, Itkin M et al. Conventional Lymphangiography (CL) in the Management of Postoperative Lymphatic Leakage (PLL): A Systematic Review. Fortschr Röntgenstr 2020; 192: 1025 - 1035.

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.

Thoracic duct-to-vein anastomosis for the management of thoracic duct outflow obstruction in newborns and infants: a CASE series

BACKGROUND

Thoracic duct (TD) outflow obstruction causes high morbidity and mortality in newborns. It can be congenital/idiopathic or acquired (secondary to central venous thrombosis or injury during cardiothoracic surgery). Re-routing the TD to the venous system by microsurgical techniques to restore lymphatic flow is a potential surgical solution. We present a series of newborns and infants who underwent thoracic duct-to-vein anastomosis (TDVA) to restore TD outflow.

MATERIALS AND METHODS

A retrospective review of all TDVA September 2015-March 2019 was performed. All patients underwent extensive pre-operative imaging evaluation by dynamic MRI and fluoroscopic lymphangiography. The TDVAs were done under high-power microscopy.

RESULTS

Eight patients underwent TDVA. Age at surgery was 1 to 9 months. Four patients had a history of cardiac surgery (one with complete thrombosis of the central venous system), one patient had a history of ECMO and thrombosis of the SVC, and three patients had a history of fetal hydrothorax and non-immune hydrops. Six patients had a successful TDVA with restoration of the lymphatic flow through the TD and clinical improvement. Two patients had a technically adequate TDVA but without improvement of the flow due to persistently high central venous pressure. Five patients remain alive, two patients died from complications of the lymphatic disorder, and one patient died from an unrelated cause.

CONCLUSIONS

Patients with congenital or acquired TD outlet obstruction for whom no improvement is achieved by non-surgical interventions may benefit from TDVA. A thorough understanding of the anatomy and physiology of each patient is critical for the success of the operation.

LEVEL OF EVIDENCE

Level IV.

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.

Establishment of hepatocellular carcinoma patient-derived xenografts from image-guided percutaneous biopsies

While patient-derived xenograft (PDX) models of hepatocellular carcinoma (HCC) have been successfully generated from resected tissues, no reliable methods have been reported for the generation of PDXs from patients who are not candidates for resection and represent the vast majority of patients with HCC. Here we compare two methods for the creation of PDXs from HCC biopsies and find that implantation of whole biopsy samples without the addition of basement membrane matrix favors the formation of PDX tumors that resemble Epstein-Barr virus (EBV)-driven B-cell lymphomas rather than HCC tumors. In contrast, implantation with Matrigel supports growth of HCC cells and leads to a high rate of HCC tumor formation from these biopsies. We validate the resulting PDXs, confirm their fidelity to the patients’ disease and conclude that minimally invasive percutaneous liver biopsies can be used with relatively high efficiency to generate PDXs of HCC.

Cost-Effectiveness of Percutaneous Lymphatic Embolization for Management of Plastic Bronchitis

BACKGROUND

Plastic bronchitis is a dreaded complication of single ventricle physiology occurring following palliation via Fontan procedure. Medical management of plastic bronchitis often fails, requiring heart transplantation. Percutaneous lymphatic embolization is an emerging treatment for plastic bronchitis.

METHODS

To determine the cost-effectiveness of competing management strategies, a modified Markov model was constructed with patients transiting through treatments-medical management, lymphatic embolization, or heart transplantation from a hospital system perspective. Health state transitions were modeled using an institutional review board-approved retrospective review of the Children's Hospital of Pennsylvania's plastic bronchitis cohort. Medication pricing data were obtained from the National Inpatient Sample. Differences in costs and quality-adjusted life years (QALYs) over a five-year horizon for each group were determined. The incremental cost-effectiveness ratio was then calculated.

RESULTS

The mean cost of lymphatic embolization from procedure performance was US$340,941, US$385,841 for heart transplantation, and US$594,520 for medical management. The mean quality-adjusted survival of lymphatic embolization yielded an additional 0.66 QALYs (P < .03) relative to heart transplantation and 1.3 (P < .0001) relative to medical management. Orthotopic heart transplantation yielded an additional 0.66 QALYs (P = .06) when comparing heart transplantation to medical management. Compared to medical management, lymphatic embolization generated an incremental cost-effectiveness ratio of US$192,105. Similarly, compared to heart transplantation, lymphatic embolization yielded an incremental cost-effectiveness ratio of US$68,030.

CONCLUSIONS

Of the available plastic bronchitis treatments, with a willingness to pay of US$150,000, lymphatic embolization produces an incremental cost-effectiveness ratio within the bounds considered to be cost-effective, potentially causing financial benefits to the health system.

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.

Combined chemoembolization and thermal ablation for the treatment of metastases to the liver

PURPOSE

The purpose of the study was to evaluate safety, time to recurrence, and overall survival (OS) in patients with liver metastases (LM), treated with transarterial chemoembolization (TACE) followed by ablation.

MATERIALS AND METHODS

This retrospective study included all patients with LM treated with combined TACE and ablation from August 1998 to September 2015. Forty-two patients (12 women, 30 men; age 62.9 ± 11.9 years) were treated for 44 LMs. Tumor characteristics, imaging response to treatment, recurrence, and OS data were reviewed. Statistical analysis included Kaplan-Meier estimation, Cox regression and Fisher's exact, Wilcoxon rank sum, or log rank tests.

RESULTS

Median follow-up was 10.3 months. Eighteen patients had 1 hepatic lesion, 16 had 2-5, and 8 had > 5. Median index lesion size was 4.7 cm (range 1.5-8 .0 cm). Tumor response (mRECIST) was available for 41/44 treated lesions, with CR in 32 (78.0%), PR in 8 (19.5%), and PD in 1 (2.4%). Long-term imaging follow-up was available for 38 patients. Freedom from local recurrence was 61% at 1 year and 50% at 2 years. OS was 55% at 1 year and 30% at 2 years (median OS, 14.5 months). Tumor size and histology were not predictors of time to progression or OS. Complications occurred in 19 patients (45%). Major complications occurred in 19% of patients and included hospitalization for fever (n = 2), hepatic abscess (n = 3) and fall requiring transfusion, portal vein thrombus causing lobar infarct, biliary fistula, and retroperitoneal hematoma (n = 1 each).

CONCLUSIONS

Combined TACE and ablation is effective for local tumor control of liver metastases up to 8 cm when part of a multidisciplinary treatment strategy. Major complications occurred in 19% of patients.

Novel Lymphatic Imaging and Percutaneous Treatment of Chyluria

Chyluria is characterized by the presence of chyle in the urine and often presents clinically as urinary obstruction. Traditional treatments include dietary modifications, surgery and sclerotherapy. The recently developed intranodal lymphangiography and dynamic contrast-enhanced MR lymphangiography (DCMRL) provide better imaging of the lymphatic system. Interstitial lymphatic embolization is a new interventional technique that allows delivery of n-butyl cyanoacrylate glue into the network of the lymphatic vessels. This report describes the demonstration of lympho-urinary tract communications using DCMRL and intranodal lymphangiography in three patients who presented with chyluria, and successful treatment of chyluria in two patients using interstitial lymphatic embolization.

Electrolytic ablation enables cancer cell targeting through pH modulation

Minimally invasive ablation strategies enable locoregional treatment of tumors. One such strategy, electrolytic ablation, functions through the local delivery of direct current without thermal effects, facilitating enhanced precision. However, the clinical application of electrolytic ablation is limited by an incompletely characterized mechanism of action. Here we show that acid and base production at the electrodes precipitates local pH changes causing the rapid cell death that underlies macroscopic tumor necrosis at pH > 10.6 or < 4.8. The extent of cell death can be modulated by altering the local buffering capacity and antioxidant availability. These data demonstrate that electrolytic ablation is distinguished from other ablation strategies via its ability to induce cellular necrosis by directly altering the tumor microenvironment. These findings may enable further development of electrolytic ablation as a curative therapy for primary, early stage tumors.

Lymphangiography and thoracic duct embolization following unsuccessful thoracic duct ligation: Imaging findings and outcomes

OBJECTIVE

To summarize the imaging findings and outcomes of thoracic duct (TD) embolization (TDE) performed in patients with chylous leaks persisting after TD ligation (TDL).

MATERIALS AND METHODS

In this review of 50 patients (30 males and 20 females; median age, 54 years) referred for TDE following unsuccessful surgical TDL, records were reviewed for lymphangiographic findings, technical success of TDE, and outcome of TDE. Comparisons between groups were performed using the Fisher exact test.

RESULTS

The causes of chylothorax were traumatic in 39 patients (78%) and nontraumatic in 11 (22%). Lymphangiography identified missed TDL in 30 patients (60%) and complete TDL in 15 patients (30%); however, in 12 of these 15 patients, collaterals around the ligation site supplying the leak could be identified. Incomplete ligation was observed in 4 patients (8%). In 1 patient (2%), a second TD was identified circumventing a complete ligation of the main TD. TDE was performed in 49 patients, and TD disruption was performed in 1 patient. Resolution of the chylous leak occurred in 45 patients (90%). There were 3 minor complications that resulted in no clinical sequela.

CONCLUSIONS

TDE produced cessation of chylous leak in the majority of the patients with persistent chylothorax after surgical TDL. Missed ligation is the most common finding on lymphangiography in patients with failed TDL. These findings support the use of image-guided closure of TD leaks.

Modern Techniques of Lymphangiography and Interventions: Current Status and Future Development

One of the crucial functions of the lymphatic system is maintenance of fluid balance. Nonetheless, due to lack of clinical imaging and interventional techniques, the lymphatic system has been under the radar of the medical community. The recently developed intranodal lymphangiography and dynamic contrast-enhanced MR lymphangiography provide new insight into lymphatic pathology. Thoracic duct embolization has become the method of choice for the treatment of patients with chylous leaks. Interstitial lymphatic embolization further expanded the lymphatic embolization approaches. Liver lymphatic lymphangiography and embolization allow treatment of postsurgical liver lymphorrhea and protein-losing enteropathy. The potential for further growth of lymphatic interventions is vast and includes liver lymphatic procedures and advanced thoracic duct interventions, such as thoracic duct externalization and stenting. These current and future advances will open up a realm of new treatments and diagnostic opportunities.

The 2017 Integrated IR Residency Match: Results of a National Survey of Applicants and Program Directors

PURPOSE

To characterize and compare the experiences of matched applicants and program directors (PDs) participating in the first large-scale integrated interventional radiology (IR) residency match.

MATERIALS AND METHODS

Survey questionnaires were distributed nationally to integrated IR applicants who matched in the 2017 Match cycle and PDs. Both groups were questioned regarding their experiences with the application, interview, rank, and match processes as well as applicant-specific and PD-specific information. Summary and descriptive statistics were applied to responses, and comparison of Likert scale responses was performed by two-sample t test.

RESULTS

Sixty-one matched applicants (51.3%) and 34 PDs (55.7%) responded to the survey. Regarding the match process, applicants believed United States Medical Licensing Examination (USMLE) Step 1 score (P = .002) and connection to a program's geographic location (P = .006) were significantly more important than PDs did, whereas PDs ranked grades (P = .049), class rank (P = .011), academic awards (P = .003), additional degrees (P < .001), and USMLE Step 2 Clinical Skills score (P < .001) as significantly more important factors than applicants did. Additional information regarding demographic data, medical school experiences in IR, application strategies, interview experiences, rank lists, the intern year, and match results are reported.

CONCLUSIONS

The completion of the first large-scale integrated IR match represents a paradigm shift in the way in which IR practitioners are recruited and trained. This study provides valuable benchmark data and analysis that can be used to improve efforts to match the best-fitting applicants into the integrated IR residency and improve future match cycles for applicants and PDs alike.

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.

Passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts and assessment of clinical outcomes

AIM

To assess for passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts (TIPS) and compare outcomes with maximally dilated TIPS.

METHODS

Polytetrafluoroethylene covered TIPS (Viatorr) from July 2002 to December 2013 were retrospectively reviewed at two hospitals in a single institution. Two hundred and thirty patients had TIPS maximally dilated to 10 mm (mTIPS), while 43 patients who were at increased risk for hepatic encephalopathy (HE), based on clinical evaluation or low pre-TIPS portosystemic gradient (PSG), had 10 mm TIPS sub-maximally dilated to 8 mm (smTIPS). Group characteristics (age, gender, Model for End-Stage Liver Disease score, post-TIPS PSG and clinical outcomes were compared between groups, including clinical success (ascites or varices), primary patency, primary assisted patency, and severe post-TIPS HE. A subset of fourteen patients with smTIPS underwent follow-up computed tomography imaging after TIPS creation, and were grouped based on time of imaging (< 6 mo and > 6 mo). Change in diameter and cross-sectional area were measured with 3D imaging software to evaluate for passive expansion.

RESULTS

Patient characteristics were similar between the smTIPS and mTIPS groups, except for pre-TIPS portosystemic gradient, which was lower in the smTIPS group (19.4 mmHg ± 6.8 vs 22.4 mmHg ± 7.1, P = 0.01). Primary patency and primary assisted patency between smTIPS and mTIPS was not significantly different (P = 0.64 and 0.55, respectively). Four of the 55 patients (7%) with smTIPS required TIPS reduction for severe refractory HE, while this occurred in 6 of the 218 patients (3%) with mTIPS (P = 0.12). For the 14 patients with follow-up computed tomography (CT) imaging, the median imaging follow-up was 373 d. There was an increase in median TIPS diameter, median percent diameter change, median area, and median percent area change in patients with CT follow-up greater than 6 mo after TIPS placement compared to follow-up within 6 mo (8.45 mm, 5.58%, 56.04 mm², and 11.48%, respectively, P = 0.01).

CONCLUSION

Passive expansion of smTIPS does occur but clinical outcomes of smTIPS and mTIPS were similar. Sub-maximal dilation can prevent complications related to over-shunting in select patients.

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.

Concurrent Central Venous Stent and Central Venous Access Device Placement Does Not Compromise Stent Patency or Catheter Function in Patients with Malignant Central Venous Obstruction

PURPOSE

To determine if concurrent placement of a central venous stent (CVS) and central venous access device (CVAD) compromises stent patency or catheter function in patients with malignant central venous obstruction.

MATERIALS AND METHODS

CVS placement for symptomatic stenosis resulting from malignant compression was performed in 33 consecutive patients who were identified retrospectively over a 10-year period; 28 (85%) patients had superior vena cava syndrome, and 5 (15%) had arm swelling. Of patients, 11 (33%) underwent concurrent CVS and CVAD placement, exchange, or repositioning; 22 (67%) underwent CVS deployment alone and served as the control group. Types of CVADs ranged from 5-F to 9.5-F catheters. Endpoints were CVS patency as determined by clinical symptoms or CT and CVAD function, which was determined by clinical performance.

RESULTS

All procedures were technically successful. There was no difference between the 2 groups in clinically symptomatic CVS occlusion (P = .2) or asymptomatic in-stent stenosis detected on CT (P = .5). None of the patients in the CVS and CVAD group had recurrent clinical symptoms, but 3 (30%) of 10 patients with imaging follow-up had asymptomatic in-stent stenosis. In the control group, 3 (14%) patients had clinically symptomatic CVS occlusion and required stent revision, whereas 4 (21%) of 19 patients with imaging follow-up had asymptomatic in-stent stenosis. During the study, 2 (20%) functional but radiographically malpositioned catheters were identified (0.66 per 1,000 catheter days).

CONCLUSIONS

Presence of a CVAD through a CVS may not compromise stent patency or catheter function compared with CVS placement alone.

Tumor Growth Kinetics and Oncologic Outcomes of Patients Undergoing Active Surveillance for Residual Renal Tumor following Percutaneous Thermal Ablation

PURPOSE

To evaluate growth kinetics and oncologic outcomes of patients with renal tumors undergoing active surveillance (AS) for residual viable tumor following percutaneous ablation.

MATERIALS AND METHODS

Following percutaneous thermal ablation, residual tumor was detected in 21/133 (16%) patients on initial follow-up imaging, and AS was undertaken in 17/21 (81%) patients. Initial tumor volumes and volumes after ablation were assessed from cross-sectional imaging to calculate volumetric growth rate (VGR) and volume doubling time (VDT) of residual tumor. The rate of metastasis, overall survival, and renal cell carcinoma (RCC)-specific survival were compared between patients in the AS group and in the routine follow up group of patients who did not have residual tumor.

RESULTS

Median tumor volume prior to ablation, after first ablation, and at final follow-up were 25 cm(3), 6 cm(3), and 6 cm(3), respectively, in patients with residual tumor. Stable, mild, and moderate VGR occurred in 8/17 (47%), 4/17 (24%), and 5/17 (29%) cases, respectively. The 4 cases with fastest VDT underwent delayed intervention with ablation (n = 1) and nephrectomy (n = 3) without subsequent residual, recurrence, or metastasis. There was no significant difference in the rates of RCC metastasis, overall survival, or RCC-specific survival between AS and routine follow-up groups. Metastatic RCC and subsequent death occurred in 1 patient in the AS group, after the patient had refused offers for retreatment for local progression over 60.7 months of follow-up.

CONCLUSIONS

In cases when patients are not amenable to further intervention, AS of residual tumor may be an acceptable alternative and allows for successful delayed intervention when needed.

Thermal Changes during Rheolytic Mechanical Thrombectomy

PURPOSE

To characterize thermal changes induced by rheolytic thrombectomy (RT) within an ex vivo venous model and evaluate resultant changes of endothelial and vessel wall injury.

MATERIALS AND METHODS

Patent human saphenous vein segments without thrombus were mounted in an ex vivo perfusion system with a temperature probe apposed to the adventitial surface. RT was performed over a guide wire to facilitate device centering. Continuous RT was performed for 4 minutes with temperature recorded every 10 seconds. Pulsed RT was performed for eight cycles of 30 seconds followed by 10 seconds of deactivation. Mean temperature increase, maximum temperature (Tmax), intimal/medial thickness, endothelial cell staining (CD31), and heat shock protein 90 (HSP90) expression were compared between untreated and RT-treated venous segments.

RESULTS

Continuous RT produced a mean 7.6°C increase in temperature above baseline with mean Tmax of 44.1°C. Pulsed RT produced a mean 7.3°C increase in temperature and mean Tmax of 43.8°C. Differences in mean temperature increase (P = .66) and Tmax (P = .71) between the two groups were not statistically significant. RT-treated segments showed intima/media thinning (0.32 mm before RT and 0.18 mm after RT; P = .004) and reduction in intact endothelium (38.8% before RT and 13.8% after RT; P = .002). Staining for HSP90 showed a 3.1% increase in expression after RT (P = .31).

CONCLUSIONS

RT in this venous model showed reproducible increases in vessel temperature and evidence of endothelial and vessel wall injury. Avoiding prolonged RT application to a focal vascular segment during clinical use may be beneficial.

Correlation of Peripheral Vein Tumour Marker Levels, Internal Iliac Vein Tumour Marker Levels and Radical Prostatectomy Specimens in Patients with Prostate Cancer and Borderline High Prostate-Specific Antigen: A Pilot Study

PURPOSE

To correlate prostate-specific antigen (PSA), free to total PSA percentage (fPSA%) and prostatic acid phosphatase (PAP) levels from peripheral and pelvic venous samples with prostatectomy specimens in patients with prostate adenocarcinoma and borderline elevation of PSA.

MATERIALS AND METHODS

In this prospective institutional review board approved study, 7 patients with biopsy proven prostate cancer had a venous sampling procedure prior to prostatectomy (mean 3.2 days, range 1-7). Venous samples were taken from a peripheral vein (PVS), the right internal iliac vein, a deep right internal iliac vein branch, left internal iliac vein and a deep left internal iliac vein branch. Venous sampling results were compared to tumour volume, laterality, stage and grade in prostatectomy surgical specimens.

RESULTS

Mean PVS PSA was 4.29, range 2.3-6 ng/ml. PSA and PAP values in PVS did not differ significantly from internal iliac or deep internal iliac vein samples (p > 0.05). fPSA% was significantly higher in internal iliac (p = 0.004) and deep internal iliac (p = 0.003) vein samples compared to PVS. One of 7 patients had unilateral tumour only. This patient, with left-sided tumour, had a fPSA% of 6, 6, 6, 14 and 12 in his peripheral, right internal iliac, deep right internal iliac branch, left internal iliac and deep left internal iliac branch samples respectively. There were no adverse events.

CONCLUSION

fPSA%, unlike total PSA or PAP, is significantly higher in pelvic vein compared to peripheral vein samples when prostate cancer is present. Larger studies including patients with higher PSA values are warranted to further investigate this counterintuitive finding.

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.

Complication and Readmission Rates following Same-Day Discharge after Percutaneous Renal Tumor Ablation

PURPOSE

To evaluate readmission rate and complications in patients undergoing same-day discharge following percutaneous thermal ablation of renal tumors.

MATERIALS AND METHODS

Patients undergoing same-day discharge following thermal ablation of renal tumors were reviewed. The primary outcome was the rate of readmission within 30 days of same-day discharge. The secondary outcomes included the rate and clinical outcomes of periprocedural complications.

RESULTS

Same-day discharge occurred in 166/174 patients (95%), of whom 2/166 (1%) required short-term readmission due to pulmonary embolism and acute-on-chronic kidney injury. Both patients recovered without permanent morbidity. Admission due to complications occurred in 8/174 (5%) cases, the majority of which were related to hemorrhage. No significant differences in rates of complications or admission were found between cryoablation and RF ablation. Major complications (Clavien-Dindo grade II or higher, SIR grade C or higher) occurred in 7/174 (4%) cases, the majority related to hemorrhage. All cases were detected in the standard 4 hour postprocedural observation period and managed conservatively. The mean hemorrhage volume was significantly larger in patients requiring admission versus those discharged the same day (289 mL vs 34 mL; P = .02). Higher-volume hemorrhage occurred in larger tumors (mean, 4.0 cm vs 3.0 cm; P = .04). There was no association between major complications and central tumor or age.

CONCLUSIONS

Routine same-day discharge following percutaneous renal tumor thermal ablation can be performed with a low rate of short-term readmission. The majority of periprocedural complications can be managed conservatively, and patients can be discharged the same day.