Preliminary Experience with a Low-Profile High-Density Braid Occluder for Transcatheter Embolization of Pulmonary Arteriovenous Malformations.

This brief report describes safety, technical feasibility, and early treatment effectiveness of the low-profile braided occluder (LOBO; Okami Medical, San Diego, Caliornia) for embolization of 9 pulmonary arteriovenous malformations (PAVMs) in 4 patients (3 female and 1 male; age range: 33 to 63 years; 3 patients showed positive results for hereditary hemorrhagic telangiectasia genes). A total of 10 occluders were deployed in 10 vessels (median treated vessel diameters, 3 and 4 mm for LOBO-3 and LOBO-5 groups, respectively). All devices were successfully deployed into the feeder pulmonary arteries, achieving complete cessation of flow. There were no severe adverse events or device migrations. Available short-term follow-up computed tomography (6 PAVMs: median, 7 months; range, 1.5-7 months) demonstrated complete occlusion without persistence or recanalization. The early experience of embolization of PAVMs using a low-profile braided occluder showed it to be safe and effective. Further studies with larger cohorts and longer follow-up periods are warranted.

Vascular Plugs Improve Pulmonary Arteriovenous Malformation Occlusion over Coil Embolization Alone: A Proof-of-Concept Study using Dual Energy Computed Tomography.

PURPOSE: To evaluate efficacy of pulmonary arteriovenous malformation (PAVM) embolization using dual-energy computed tomography (DECT) and spectral curve analysis by characterizing contrast enhancement and vascular perfusion as a surrogate of the degree of vascular occlusion after embolotherapy. METHODS: Nine consecutive adult patients underwent embolization for 21 PAVMs (size range 0.4-2.0cm; 15/21 simple angioarchitecture) and subsequent post-embolization chest DECT angiography. Twelve PAVMS were treated with vascular plugs ± coils, whereas nine PAVMs were treated with coils-only. Virtual spectral curves (VSC) were generated using dual-energy image post-processing in order to measure embolization effectiveness. RESULTS: Complete occlusion of target PAVM was achieved in all cases on digital subtraction angiography at the end of the embolization procedure. With a median follow-up of 12.7 months, the vascular plug group demonstrated significantly less vascular opacification compared to the coils-only group, as measured by opacification between upstream feeding artery and and different downstream vasculature locations (Δslope1: median 79.1 versus 28.6, p=0.0030; Δslope2: 76.4 versus 28.6, p=0.0197; Δslope3: 78.9 versus 28.6, p=0.0041). Persistence occurred in three PAVMs based on size criteria, which demonstrated higher vascular vascular opacification by DECT (Δslope1: 72 versus 28.6, p=0.253; Δslope2: 65.1 versus 32.7, p=0.326; Δslope3: 72.9 versus 53.5, p=0.733), although statistical significance was not reached. CONCLUSION: Similar to emerging literature, DECT showed improved occlusion in PAVMs treated with vascular plugs compared to coils alone.

Segmental Yttrium-90 Radioembolization Using Glass Microspheres Greater than 400 Gray for the Treatment of Intrahepatic Cholangiocarcinoma: A Preliminary Experience.

Radiation segmentectomy with a dose of >190 Gy using yttrium-90 (90Y) glass microspheres for intrahepatic cholangiocarcinoma (iCCA) has been shown to be safe and effective. The present study further increased the dose to >400 Gy for treatment of iCCA as complete pathologic necrosis has been shown in hepatocellular carcinoma using this ablative approach. A total of 10 patients with 13 tumors (median size, 5.3 cm; range, 1.5-13.6 cm) at a single institution underwent >400-Gy segmental radioembolization. Objective response was achieved in all tumors (13 of 13, 100%). One patient developed a Grade 3 or greater major adverse event (stroke and hepatic decompensation). One patient was bridged to transplant (>95% pathologic necrosis), whereas another underwent resection (>99% necrosis). Contralateral hypertrophy was observed in 6 out of 6 patients treated with modified lobectomy dosing, with a functional liver reserve increase from a median of 31.5% to 57.1%. The present report suggests that segmental transarterial radioembolization with >400 Gy is feasible in terms of safety and effectiveness for treating iCCA.

Empiric Transcatheter Embolization for Acute Arterial Upper Gastrointestinal Bleeding: A Meta-Analysis.

OBJECTIVE. The purpose of this study was to conduct a meta-analysis to assess the safety and efficacy of empiric embolization compared with targeted embolization in the treatment of acute upper gastrointestinal bleeding (UGIB). MATERIALS AND METHODS. We searched the PubMed and Cochrane Library databases for studies performed without language restrictions from January 2000 to November 2019. Only clinical studies with a sample size of five or more were included. Clinical success, rebleeding and complication rates, survival rates, bleeding cause, embolic materials, and vessels embolized were recorded. Empiric embolization and targeted embolization (i.e., embolization performed based on angiographic evidence of ongoing bleeding) were compared when possible. Meta-analysis was performed. RESULTS. Among 13 included studies (12 retrospective and 1 prospective), a total of 357 of 725 patients (49.2%) underwent empiric embolization for UGIB. The clinical success rate of empiric embolization was 74.7% (95% CI, 63.1-86.3%) among the 13 studies, and the survival rate was 80.9% (95% CI, 73.8-88.0%) for 10 studies. On the basis of comparative studies, no statistically significant difference was observed between empiric and targeted embolization in terms of rebleeding rate in 111 studies (36.5% vs 29.6%; odds ratio [OR], 1.13; 95% CI, 0.77-1.65; p = .53), mortality in eight studies (23.3% vs 18.0%; OR, 1.44; 95% CI, 0.89-2.33; p = .14), and need for surgery to control rebleeding in four studies (17.8% vs 13.4%; OR, 1.34; 95% CI, 0.58-3.07; p = .49). The pooled embolization-specific complications were 1.9% (empiric) and 2.4% (targeted). CONCLUSION. According to all available published evidence, empiric embolization assessed with endoscopic or preprocedural imaging findings (or both) appears to be as effective as targeted embolization in preventing rebleeding and mortality in patients with angiographically negative acute UGIB. Because of its favorable safety profile, empiric embolization should be considered for patients in this clinical scenario.

Improved Utilization Following Conversion of a Fluoroscopy Suite to Hybrid CT/Angiography System.

PURPOSE: To assess changes in operational utilization following conversion of a single IR suite to a hybrid CT/angiography (Angio-CT) system at an academic tertiary care center. MATERIALS AND METHODS: The total number of interventional procedures and diagnostic CT examinations performed in 29 rooms (20 diagnostic radiology, 7 IR, 2 shared between divisions) was calculated in the 24 months before conversion of an IR suite to Angio-CT and 12 months after conversion. The total number of IR procedures (global IR/month) and diagnostic CT scans per month (global CT/month) in both before and after conversion periods was calculated and defined as baseline institutional growth. This was compared against the change in the number of IR procedures performed in the before and after periods in the converted room (Angio-CT/month) as well as the number of diagnostic CT scans performed in the shared rooms (shared CT/month). RESULTS: The percent change in global CT and global IR from the before to the after periods was 39.2% and 3.1%, respectively. Shared CT per month and Angio-CT per month increased by 46.7% and 12.0% across the same time periods, respectively. The ratio of the percent increase in Angio-CT per month to percent increase in global IR per month was 3.87. The ratio of the percent increase in shared CT per month to percent increase in global CT per month was 1.19. CONCLUSIONS: Operational utilization improved in both diagnostic radiology and IR sections following conversion of a conventional fluoroscopic IR suite to an Angio-CT room.

Strut penetration: local complications, breakthrough pulmonary embolism, and retrieval failure in patients with Celect vena cava filters.

PURPOSE: To investigate strut penetration in patients with Celect filters, specifically local complications and association with breakthrough pulmonary embolism (PE) or retrieval failure. MATERIALS AND METHODS: A retrospective single-center study was conducted to evaluate patients who received Celect filters between January 2007 and May 2013. A total of 595 filters were placed during the study period. Primary indications included thromboembolic disease (93%) and primary surgical prophylaxis (7%). Complications and retrieval data were assessed by computed tomography (CT) and electronic medical records. RESULTS: A total of 193 patients underwent follow-up abdominal CT at a mean follow-up interval of 176.2 days (range, 0-1,739 d). The rate of strut penetration more than 3 mm outside the caval wall was 28.5% (n = 55). One patient had CT evidence of clinically major strut penetration (1.8%) with strut compression of the right ureter causing hydronephrosis. Indwelling filter time longer than 100 days was associated with strut penetration (P < .001). Age, sex, and history of thromboembolic disease were not associated with strut penetration (P = .51, P = .81, and P = .89). Sixty-three patients presented for follow-up CT pulmonary angiography at a mean of 128.1 days (range, 1-895 d). The rate of breakthrough PE was 12.7%. The overall retrieval success rate was 96.7% (n = 150). Strut penetration was not associated with breakthrough PE or retrieval failure (P = .49 and P = .22). CONCLUSIONS: Although strut penetration is a common complication with Celect filters, there is no association with breakthrough PE or retrieval failure. CT evidence of local complications associated with strut penetration is rare.

Clinical predictors of port infections within the first 30 days of placement.

PURPOSE: To identify risk factors for port infections within 30 days of placement. MATERIAL AND METHODS: A retrospective chart review of port placements from 2002-2009 was conducted. Patients who had port removals secondary to infection within the first 30 days of placement were included. This group of patients was compared with a control group of patients with ports with no evidence of infection. For every one patient with a port infection, two control subjects were chosen of the same gender and new port placement during the same month as the corresponding patient with an infected port. RESULTS: From 2002-2009, 4,404 ports were placed. Of the 4,404 patients, 33 (0.7%) were found to have a port infection within 30 days of placement. Compared with the control group, the early infection group had a higher prevalence of leukopenia (21.2% vs 6.1%, P = .039) and thrombocytopenia (33% vs 12%, P = .0158). There was also a higher prevalence of an inpatient hospital stay during port placement and high international normalized ratio in the early infection group. CONCLUSIONS: Low preoperative white blood cell and platelet counts were risk factors for early infection. Abnormal coagulation profiles and inpatient access of ports after placement could be additional risk factors.

Comparison of barbed versus conventional sutures for wound closure of radiologically implanted chest ports.

PURPOSE: To retrospectively compare the incidences of complications with barbed suture versus conventional interrupted suture for incision closure in implantable chest ports. MATERIALS AND METHODS: A total of 715 power-injectable dual-lumen chest ports placed between 2011 and 2013 were studied. Primary outcomes included wound dehiscence, local port infection, local infections treated by wound packing, early infections within 30 days, and total infections. A multivariate analysis of independent risk factors for port infection was also performed. RESULTS: A total of 442 ports were closed with nonbarbed suture, versus 273 closed with barbed suture. Mean catheter-days in the traditional and barbed groups were 257.9 (range, 3-722) and 189.1 (range, 13-747), respectively (P < .01). The rate of dehiscence with traditional suture (1.6%; seven of 442) was significantly higher than that with barbed suture (zero of 273; P = .04). Percentage of total infections was also significantly higher with traditional suture (9.5% vs 5.1%; P = .03). No difference in rate of infection per 1,000 catheter-days was seen between traditional and barbed suture groups (0.0035 vs 0.0026; P = .17). The rate of local infection with traditional suture was significantly higher (2.7% vs 0.4%; P = .02). Additionally, multivariate analysis identified the use of traditional suture as the only independent risk factor for infection (39% vs 25%; P = .03). CONCLUSIONS: Barbed suture for incision closure in implantable dual-lumen chest ports was associated with lower rates of dehiscence and potentially lower rates of local infectious complications compared with traditional nonbarbed suture.

Evaluation and treatment of suspected type II endoleaks in patients with enlarging abdominal aortic aneurysms.

PURPOSE: To evaluate angiographic diagnosis and embolotherapy of patients with enlarging abdominal aortic aneurysms and computed tomographic (CT) diagnosis of type II endoleak. MATERIALS AND METHODS: A retrospective review was performed of all patients referred to a single vascular and interventional radiology section from January 1, 2003, to June 1, 2011, with a diagnosis of enlarging aneurysm and type II endoleak. Twenty-five patients underwent 40 procedures between 12 and 82 months after endograft insertion (mean, 48 mo) for diagnosis and/or treatment of endoleaks. RESULTS: Type II endoleaks were treated with cyanoacrylate, coils, and ethylene vinyl alcohol copolymer in 16 patients. Technical success rate was 88% (14 of 16 patients) and clinical success rate was 100% (16 of 16 patients). Aneurysm growth was arrested in all cases over a mean follow-up of 27.5 months (range, 6-88 mo). Endoleaks in nine patients were misclassified on CT; two had type I endoleaks and seven had type III endoleaks. Four of the nine patients (two type I endoleaks and two type III endoleaks) were correctly classified after initial angiography. The other five type III endoleaks were correctly classified on CT after coil embolization of the inferior mesenteric artery. Direct embolization was performed via sac puncture with ethylene vinyl alcohol copolymer in two of the latter five patients and eliminated endoleaks in both. CONCLUSIONS: Aneurysm growth caused by type II endoleaks was arrested by embolization. CT misclassification occurred relatively commonly; type III endoleaks purported to be type II endoleaks were found in 28% of patients (seven of 25).

Social Media Growth at Annual Medical Society Meetings: A Comparative Analysis of Diagnostic and Interventional Radiology to Other Medical Specialties.

OBJECTIVE: To understand social media growth in both diagnostic and interventional radiology compared to other related specialties by quantifying and comparing hashtag utilization at annual medical conferences. METHODS: Official annual conference hashtags for Society of Interventional Radiology (SIR), American College of Radiology (ACR), Radiological Society of North America, American College of Cardiology, American Heart Association, and American Society of Clinical Oncology were analyzed from 2015 to 2019, along with the IR hashtag #IRad. Twitter analytics were obtained with the use of Symplur Signals, a healthcare social media analytics platform. Linear regression analysis was performed on the number of tweets and users for each hashtag. RESULTS: For annual ACR meetings, the number of tweets/user (6.96 in 2019), retweets/user (4.39 in 2019), and impressions/user (40,051 in 2019) were among the highest of all the specialties studied. This trend was observed despite a smaller number of users among ACR than most other conferences. SIR tweets increased significantly at a rate of 1032.8 tweets/year (P = 0.008) while users also significantly grew at a rate of 212.5 users/years (P = 0.007). #IRad tweets are also growing at a rate of 13,234.8 tweets/year (P = 0.026) while #IRad users are growing at a rate of 1309.5 users/year (P = 0.003). Radiological Society of North America users were significantly decreasing at -1207.1 users/year (P = 0.018). CONCLUSION: ACR consistently had one of the highest counts of tweets/user, retweets/user, and impressions/user compared to the other studied specialties, suggesting that ACR's Twitter users are more active than users outside of the field of radiology. SIR was the only studied specialty conference that had statistically significant increases in the number of tweets and users.

Hybrid angiography-CT for transarterial radioembolization: a pictorial essay.

Although hybrid angiography-CT (Angio-CT) has a long history of use for interventional oncology procedures, its applications for transarterial radioembolization (TARE) are not as well described in the literature. This pictorial essay demonstrates a single-institution experience with the utilization of an Angio-CT system for TARE treatment of hepatocellular carcinoma. Procedural images and clinical data for twenty-four patients who underwent initial angiographic mapping with hepatopulmonary shunt fraction assessment and or administration of Yttrium-90 (Y-90) microspheres using the Angio-CT system to date were reviewed. Cases were reviewed for examples that highlight the specific utility of Angio-CT. Three representative TARE cases were selected which illustrate unique advantages and applications of the Angio-CT system when performing TARE. These include the ability to optimally delineate hepatic vascular anatomy, accurately calculate liver volumes for dosimetry, and improve the detection and characterization of equivocal lesions. Angio-CT has unique advantages which can be applied to TARE treatment of patients with HCC. The technology has potential to be an especially effective tool for those who aim to be at the cutting edge of the rapidly growing field of interventional oncology.

Safety and efficacy of repeat Y90 radioembolization to the same hepatic arterial territory.

OBJECTIVE: To study the efficacy and safety of repeat transarterial radioembolization (TARE) to similar hepatic arterial territories. METHODS: Between 3/2011 and 4/2019, 26 patients (25 males and 1 Female, Mean Age: 65 yo, SD: 11.7 yo, Range: 18-83.0 yo) received TARE with Y90 glass microspheres to treat recurrent or residual primary disease in similar hepatic arterial lobe or segments. Tumor response was evaluated by imaging using the modified-RECIST criteria. Incidence of RILD and adverse events were categorized by a standardized scale using the Common Terminology Criteria for Adverse Events (CTCAE) v.4.0. RESULTS: Mean cumulative activity after the first treatment was 2.50 GBq (SD:1.04 GBq, Range:0.61-4.93 GBq) and second treatment was 2.27 GBq (SD:1.01 GBq, Range:0.92-5.46 GBq). Mean interval time between initial and repeat treatments was 9.6 months (Range: 1-53 months). Tumor responses were complete, partial, or progression in 73% (n = 19/26), 23% (n = 6/26), and 4% (n = 1/26) in repeat treatment patients, respectively. The incidence of RILD was 0%. Toxicity after first and second treatment was seen in 19% (n = 5/26) & 23% (n = 6/26) patients, respectively, and were all of CTCAE Grade 2. No significant predictors of treatment toxicity for repeat treatment were identified except increased MELD score (p = 0.04). Kaplan-Meier survival analysis in patients with repeat treatment showed a median survival of 15.0 months (95% CI 8.8-21.1 months) and 19.0 months (95% CI 8.1-29.9 months) in patients who only received one treatment with a p value of 0.485. CONCLUSION: Repeat TARE with glass microspheres was an effective and safe treatment strategy for disease management in patients with residual or recurrent disease to the similar hepatic arterial territories without any major treatment related toxicity. ADVANCES IN KNOWLEDGE: Although safety and efficacy of repeat radioembolism has been studied, no study has focused on repeat treatment to similar hepatic arterial territories. The current study shows that repeat treatment to the same hepatic arterial territory is as safe as single treatment to the same territory.

Post-Hoc Analysis of a Randomized, Double Blind, Prospective Study at the University of Chicago: Additional Standardizations of Trial Protocol are Needed to Evaluate the Effect of a CXCR1/2 Inhibitor in Islet Allotransplantation.

A recent randomized, multicenter trial did not show benefit of a CXCR1/2 receptor inhibitor (Reparixin) when analysis included marginal islet mass (>3,000 IEQ/kg) for allotransplantation and when immunosuppression regimens were not standardized among participating centers. We present a post-hoc analysis of trial patients from our center at the University of Chicago who received an islet mass of over 5,000 IEQ/kg and a standardized immunosuppression regimen of anti-thymocyte globulin (ATG) for induction. Twelve islet allotransplantation (ITx) recipients were randomized (2:1) to receive Reparixin (N = 8) or placebo (N = 4) in accordance with the multicenter trial protocol. Pancreas and donor characteristics did not differ between Reparixin and placebo groups. Five (62.5%) patients who received Reparixin, compared to none in the placebo group, achieved insulin independence after only one islet infusion and remained insulin-free for over 2 years (P = 0.08). Following the first ITx with ATG induction, distinct cytokine, chemokine, and miR-375 release profiles were observed for both the Reparixin and placebo groups. After excluding procedures with complications, islet engraftment on post-operative day 75 after a single transplant was higher in the Reparixin group (n = 7) than in the placebo (n = 3) group (P = 0.03) when islet graft function was measured by the ratio of the area under the curve (AUC) for c-peptide to glucose in mixed meal tolerance test (MMTT). Additionally, the rate of engraftment was higher when determined via BETA-2 score instead of MMTT (P = 0.01). Our analysis suggests that Reparixin may have improved outcomes compared to placebo when sufficient islet mass is transplanted and when standardized immunosuppression with ATG is used for induction. However, further studies are warranted. Investigation of Reparixin and other novel agents under more standardized and optimized conditions would help exclude confounding factors and allow for a more definitive evaluation of their role in improving outcomes in islet transplantation. Clinical trial reg. no. NCT01817959, clinicaltrials.gov.

Interventional Radiology in Pelvic Trauma.

Traumatic pelvic injuries are associated with high injury severity scores and significant morbidity and mortality. As fractures and ligamentous disruption result in increased pelvic volume, retroperitoneal hemorrhage can spiral and progress to hemorrhagic shock. Due to the extensive collateral supply and limitations of surgery for pelvic hematomas, angiographic treatment is at the forefront of pelvic trauma management. This article will discuss typical injuries seen in pelvic trauma, treatment modalities available to the interventional radiologist, and common angiographic treatment strategies and techniques.

Transsplenic portal vein recanalization and direct intrahepatic portosystemic shunt placement to optimize liver transplantation.

BACKGROUND: Percutaneous trans-splenic portal vein recanalization (PVR) has been reported for facilitation of transjugular intrahepatic portosystemic shunts (TIPS), however has not been applied to patients undergoing direct intrahepatic portosystemic shunt (DIPS). We report the utilization of trans-splenic-PVR with DIPS creation in a patient with chronic portal and hepatic vein occlusions undergoing liver transplantation evaluation. CASE PRESENTATION: A 48-year-old male with decompensated alcoholic cirrhosis complicated by refractory ascites, hepatic encephalopathy, and variceal bleeding underwent CT that demonstrated chronic occlusion of the hepatic veins (HV), extrahepatic portal vein (PV), and superior mesenteric vein (SMV). Due to failed attempts at TIPS at outside institutions, interventional radiology was consulted for portal vein recanalization (PVR) with TIPS to treat the portal hypertension and ascites and also facilitate an end-to-end PV anastomosis at transplantation. After an initial hepatic venogram confirmed chronic HV occlusion, a DIPS with trans-splenic PVR was planned. The splenic vein was accessed under sonographic guidance using a micropuncture set and subsequently upsized to a 6 French sheath over a stiff guidewire. A splenic venogram via this access confirmed occlusion of the PV with drainage of the splenic vein (SV) through gastric varices. The thrombosed PV was then recanalized and angioplastied to restore PV flow via the transsplenic approach. A transjugular liver access kit with a modified 21-gauge needle was advanced into the IVC through the internal jugular vein (IJV) sheath and directed towards the target snare in PV. The needle was used to subsequently puncture the PV through the caudate lobe and facilitate placement of a wire into the SV. The initial portosystemic gradient (PSG) was 20 mmHg. The IJV sheath was advanced through the hepatic parenchymal tract into the main-PV and a stent-graft was placed across the main PV and into the IVC. A portal venogram demonstrated brisk blood flow through the DIPS, resolution of varices and a PSG of 8 mmHg. One month after the procedure, the patient had a significant reduction in ascites and MELD-NA score. Patient is currently listed and awaiting transplantation. CONCLUSIONS: In the setting of chronically occluded portal and hepatic veins, trans-splenic PVR DIPS may serve as an effective bridge to liver transplantation by facilitating an end to end portal vein anastomosis.