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.

A Review of Professional Liability in IR: Sweeping the Mines.

Medical professional liability (MPL) is becoming a substantial issue in interventional radiology (IR), with both impact on health care costs and negative psychological effects on physicians. MPL presents special challenges within IR because of the field's complex and innovative therapies that are provided to a diverse group of patients and complicated by the off-label use of devices and drugs that is pervasive in the field. This review discusses the principles and practices to avoid and manage MPLs that are specific to the field of IR.

Inferior Vena Cava Filter Litigation Review: An Analysis of Medicolegal Cases Pertaining to Inferior Vena Cava Filters.

PURPOSE: To identify and analyze all medical malpractice and product liability lawsuits pertaining to inferior vena cava (IVC) filters published within a well-recognized legal research database. MATERIALS AND METHODS: LexisNexis, a legal research database, was used to retrieve cases that mentioned harm from IVC filters, or lack thereof, as the cause for legal action. A total of 672 cases were analyzed for type of case (medical malpractice or product liability), filter model implanted, filter complications, court decisions, and settlement payments if any. RESULTS: Of 95 analyzed cases, 20 (21.1%) were medical malpractice cases and 75 (78.9%) were product liability cases. C.R. Bard was the manufacturer associated with the most lawsuits (n = 41, 48.8%). The most litigious filters were the G2 filter from C.R. Bard (n = 17, 20.2%) and Greenfield filter from Boston Scientific (n = 17). The most common complications were IVC penetration (n = 26, 29.9%), filter migration (n = 26, 29.9%), filter fracture (n = 23, 26.4%), and tilt (n = 16, 18.4%). The number of product liability cases has increased from accounting for 25.0% (2 of 8) of filter lawsuits between 2000 and 2010 to 83.9% (73 of 87) during 2011-2020. Of the 20 medical malpractice claims, 9 (45%) were filed for failure to place a filter. One physician was found liable for filter-related complications by a state court in 2014. CONCLUSIONS: The majority of recent IVC filter-related lawsuits are filed against manufacturers on the basis of product liability claims, with the main litigious filters being the G2 and Greenfield filters. Most cases resulted in rulings for physicians or manufacturers. Some were filed against physicians for filter-related complications or for failure to place an IVC filter.

Impact of Portal Hypertension on Adverse Events after Splenic Arterial Aneurysm Embolization.

PURPOSE: To evaluate the outcomes of splenic artery aneurysm (SAA) embolization and compare adverse event (AE) rates after embolization in patients with and without portal hypertension (PHTN). MATERIALS AND METHODS: A retrospective review of all patients who underwent embolization of SAAs at 2 institutions was performed (34 patients from institution 1 and 7 patients from institution 2). Baseline demographic characteristics, preprocedural imaging, procedural techniques, and postprocedural outcomes were evaluated. Thirty-day postprocedural severe and life-threatening AEs were evaluated using the Society of Interventional Radiology guidelines. Thirty-day mortality and readmission rates were also evaluated. t test, χ2 test, and/or Fisher exact test were used for the statistical analysis. RESULTS: There was no statistically significant difference between patients with and without PHTN in the location, number, and size of SAA(s). All procedures were technically successful. There were 13 (32%) patients with and 28 (68%) patients without PHTN. The 30-day mortality rate (31% vs 0%; P = .007), readmission rates (61% vs 7%; P < .001), and severe/life-threatening AE rates (69% vs 0%; P < .001) were significantly higher in patients with PHTN than in those without PHTN. CONCLUSIONS: There was a significantly higher mortality and severe/life-threatening AE rate in patients with PHTN than in those without PHTN. SAAs in patients with PHTN need to be managed very cautiously, given the risk of severe/life-threatening AEs after embolization.

Radiation Dose during Transarterial Radioembolization: A Dosimetric Comparison of Cone-Beam CT and Angio-CT Technologies.

PURPOSE: To evaluate the radiation dose differences for intraprocedural computed tomography (CT) imaging between cone-beam CT and angio-CT acquired during transarterial radioembolization (TARE) therapies for hepatocellular carcinoma. MATERIALS AND METHODS: A retrospective cohort of 22 patients who underwent 23 TARE procedures were selected. Patients were imaged in both cone-beam CT and angio-CT rooms as a part of their conventional treatment plan. Effective dose contributions from individual CT acquisitions as well as the cumulative dose contributions from procedural 3D imaging were evaluated. Angiography dose contributions were omitted. Cone-beam CT images were acquired on a C-arm Philips Allura system. Effective doses were evaluated by coupling previously published conversion factors (effective dose per dose-area product) to patient's dose-area product meter readings after the procedure. Angio-CT images were acquired on a hybrid Canon Infinix-i Aquilion PRIME system. Effective doses from angio-CT scans were estimated using Radimetrics. Comparisons of a single patient's dose differential between the 2 technologies were made. RESULTS: The mean effective dose from a single CT scan was 6.42 mSv and 5.99 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .3224), despite the greater field of view and average craniocaudal scan coverage in angio-CT. The mean effective dose summed across all CTs in a procedure was 12.89 mSv and 34.35 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .0018). CONCLUSIONS: The mean effective dose per CT scan is comparable between cone-beam CT and angio-CT when considered in direct comparison for a single patient.

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.

A Single-Institutional Comparative Analysis of Advanced Versus Standard Snare Removal of Inferior Vena Cava Filters.

PURPOSE: To investigate differences in procedure time, radiation exposure, and periprocedural complications associated with advanced inferior vena cava (IVC) filter retrieval compared with standard snare retrieval. MATERIALS AND METHODS: A total of 378 patients underwent standard or advanced IVC filter retrieval over a 5-year period. Technical success, retrieval techniques, fluoroscopy time, radiation dose, and complications were analyzed. All retrieval procedures with techniques other than a "snare-and-sheath" method were categorized as advanced, including failed standard attempts requiring intraprocedural conversion to advanced techniques. RESULTS: A total of 462 filter retrieval attempts were made in 378 patients (57% female). Success rates for standard and advanced retrieval attempts were 86.8% (317 of 365) and 91.8% (89 of 97), respectively. The rate of periprocedural complications was significantly higher in the advanced retrieval group (P = .006). Complication rates for standard and advanced retrievals were 0.6% (2 of 318; all minor) and 5.2% (5 of 97; 3 minor [3.1%] and 2 major [2.1%]), respectively. The 2 major complications during advanced retrievals included filter fracture and embolization. Average fluoroscopy time for advanced retrievals was significantly higher than for standard retrievals (23.1 min vs 4.3 min; P < .001). Average radiation dose for advanced retrievals was also significantly higher than for standard retrievals (557.2 mGy vs 156.9 mGy; P < .001). Use of general anesthesia was also significantly more common in advanced retrievals compared with standard retrievals (6.2% vs 0.9%; P = .002). CONCLUSIONS: Advanced filter retrieval results in a similarly high rate of technical success compared with standard snare retrieval but is associated with greater fluoroscopy time, anesthesia requirements, and radiation exposure.

Low Utility of Screening Hematologic Testing for Image-Guided Biopsies in Patients Without Bleeding Risks.

OBJECTIVE. This study evaluates the prevalence of an abnormal international normalized ratio (INR) and platelet count before image-guided percutaneous needle biopsies over a 10-year period, comparing data from patients with and those without known conditions predisposing to coagulopathy. MATERIALS AND METHODS. A review of electronic medical records identified patients who were scheduled for a biopsy in a single institution's radiology department for the period of 2007-2016. The following information was recorded: demographic data, patient history of conditions that predispose to bleeding (e.g., liver disease, anticoagulant therapy, history of coagulopathy), and INR and platelet values within 30 days before biopsy. Data were stratified by biopsies that were performed versus those that were cancelled. RESULTS. Over 10 years, 3864 percutaneous biopsies were performed, and 6371 were cancelled. Approximately half of the biopsies (48.2%) were performed in patients without a predisposing condition; of those patients, 0.8% and 0.1% had an INR greater than 1.5 and greater than 1.8, respectively, and 0.4% had a platelet count of 50,000/µL or less (≤ 50 × 109/L). In patients with no known predisposing condition, 0.6% and 0.0% of biopsies cancelled were in patients who had an INR greater than 1.5 and greater than 1.8, respectively, and 0.1% of biopsies cancelled were in patients who had a platelet count of 50,000/µL or less. Ordering prebiopsy testing of patients with no predisposing conditions for the 1864 percutaneous biopsies performed over the 10-year study period resulted in more than $850,000 in laboratory-related health care costs. Our results suggest that the cost of identifying one abnormal INR is nearly $700,000. CONCLUSION. For patients without any known bleeding risks who are scheduled to undergo image-guided percutaneous biopsies, identifying an abnormal INR or abnormal platelet count is rare. Eliminating this testing in patients without predisposing conditions has the potential to create savings in costs and time for both physicians and patients.

Medical Malpractice Primer for Practicing Interventional Radiologists.

Medical professional liability (MPL), also commonly referred to as medical malpractice, is a costly issue in health care today, accounting for roughly 2.4% of total health care expenditure in the United States. Almost all physicians currently in clinical practice will either be subject to a lawsuit themselves or work with someone who has. Given a lack of formal structured education about MPL in medicine for trainees, this review aims to define and discuss the relevant concepts in MPL as a reference for early career interventionalists to understand the current medicolegal environment and learn best practices to avoid litigation.

Inferior Vena Cava Filter Evaluation and Management for the Diagnostic Radiologist: A Comprehensive Review Including Inferior Vena Cava Filter-Related Complications and PRESERVE Trial Filters.

Inferior vena cava filters are commonly encountered devices on diagnostic imaging that were highlighted in a 2010 Food and Drug Administration safety advisory regarding their complications from long-term implantation. The Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE) trial is an ongoing after-market study investigating the safety and utility of commonly utilized filters in practice today. While most of these filters are safe, prompt recognition and management of any filter-associated complication is imperative to prevent or reduce the morbidity and mortality associated with them. This review is aimed at discussing the appropriate utilization and placement of inferior vena cava filters in addition to the recognition of filter-associated complications on cross-sectional imaging. An overview of the PRESRVE trial filters is also provided to understand each filter's propensity for specific complications.