Deciphering the Radiation Dose Summary Page in Interventional Fluoroscopy.

Fluoroscopy is an advanced medical imaging modality that utilizes x-rays to acquire real-time images throughout a medical examination. It is commonly used in various procedures such as in interventional radiology, cardiac catheterization, and gastrointestinal and genitourinary studies. While fluoroscopy is a valuable diagnostic and therapeutic tool, it exposes patients and medical staff to ionizing radiation, which carries health risks. A radiation dose summary page is a report generated by the fluoroscope that displays important information about the procedure. It provides an overview of the radiation doses administered during a fluoroscopic procedure, as well as certain technical parameters used during the irradiation events. The contents of a radiation dose summary page may vary depending on the make and model of the fluoroscope but some common elements include the cumulative reference air kerma, which serves as a surrogate of radiation dose delivered to the patient, and the dose-area product, which takes account of the x-ray beam area and is a measure of the total amount of energy imparted on the patient. Other imaging acquisition parameters may be also included in the dose summary page, including tube voltage, tube current, pulse width, pulse rate, spectral filters, primary and secondary angles, and source-to-image distance. The radiation dose summary page for fluoroscopy is a useful tool for physicians, technologists, and medical physicists, allowing them to comprehend the technical details of a fluoroscopically guided procedure. ©RSNA, 2024.

Median Arcuate Ligament Compression Associated with Flow-Related Visceral Aneurysms.

PURPOSE: To identify risk factors for rupture, and to determine outcomes of endovascular treatment of median arcuate ligament (MAL) compression-related visceral artery aneurysms (VAAs). METHODS AND MATERIALS: A retrospective review of patients who presented with MALC-related VAAs was performed from 1999 to 2021. A total of 21 patients (12 men) and 39 VAAs associated with MAL compression were encountered (mean age, 59 years). Imaging studies were reviewed for the number, morphology/size, and recurrence of aneurysms. Statistical analysis was performed to identify risk factors for rupture. RESULTS: Ten patients presented with acute rupture, and 12 patients were symptomatic with nonspecific abdominal pain. Twenty-two aneurysms were fusiform in morphology and 17 aneurysms were saccular in morphology. Of the 14 aneurysms that presented with acute hemorrhage, 12 (86%) were fusiform in morphology (odds ratio, 9.0; P < .01). The mean aneurysm size was 1.3 cm, and the mean ruptured size was 0.6 cm. Thirty-one aneurysms were treated by endovascular techniques, and technical success was achieved in all cases. Fourteen patients were found to have an Arc of Buhler. No procedure-related adverse events occurred. No patient underwent surgical ligament release. The mean time of follow-up was 3.2 years, and no aneurysms recurred after endovascular treatment. CONCLUSIONS: MAL compression-associated VAAs are an important clinical entity that should be treated even at small sizes, particularly if they are fusiform in morphology. Endovascular therapy is safe and feasible and results in durable aneurysm exclusion.

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.

Combined cut down and endovascular retrieval of orphaned ventriculoatrial shunt with stenting of chronic superior vena cava occlusion.

Revascularization of the superior vena cava (SVC) in the context of symptomatic luminal obstruction is a therapeutic intervention performed for SVC syndrome of benign or malignant etiology. Venous occlusion can preclude future access and cause symptoms ranging from mild chest discomfort to the more serious effects of SVC syndrome. This case report demonstrates the treatment of a novel case of SVC syndrome arising from a previously placed SVC stent. An intravascular, extraluminal orphaned ventriculoatrial shunt was used to go through the SVC but around the existing lumen-limiting stent to place a new larger stent for revascularization. This case highlights the need for an innovative approach for complex foreign body retrieval and treatment of chronic SVC occlusion.

Predictors of Disease Recurrence after Venoplasty and Stent Placement for May-Thurner Syndrome.

PURPOSE: To identify factors independently associated with disease recurrence after venoplasty and stent placement for May-Thurner syndrome (MTS). MATERIALS AND METHODS: Fifty-nine consecutive patients (age, 47 y ± 15; 93% female) were identified who had undergone endovascular stent placement for MTS. Patient charts were reviewed for demographic data, risk factors for venous thrombosis, comorbidities, and venous inflow or outflow at first follow-up (3 wk to 6 mo after treatment). Logistic regression was used to identify independent predictors of symptom recurrence or repeat intervention, and multivariate analysis of variance and receiver operator characteristic curve analysis were used to assess relationships between degrees of in-stent stenosis and other variables in the 73% of patients with available cross-sectional imaging. Median follow up was 20.7 months (interquartile range, 4.7-49.5 mo). RESULTS: All procedures were technically successful. Disease recurrence, defined as symptom recurrence following initial postprocedural resolution, was observed in 38% of patients. No preprocedural variable was found to be independently predictive of disease recurrence; however, poor venous inflow or outflow were both strongly associated with recurrent disease, with adjusted odds ratios and 95% confidence intervals of 38.02 (3.76-384.20; P = .002) and 7.00 (1.15-42.71; P = .04), respectively. Higher degrees of in-stent stenosis were also associated with symptom recurrence, with an area under the curve of 0.93 (P = .000002) and 39%-41% stenosis being 78%-83% sensitive and 88%-92% specific for symptom recurrence. CONCLUSIONS: These results suggest that cross-sectional imaging can help differentiate patients in whom closer follow-up may be warranted after venoplasty and stent placement for MTS and also guide counseling regarding prognosis.

Cost-Effectiveness of a Guided Peripherally Inserted Central Catheter Placement System: A Single-Center Cohort Study.

PURPOSE: To assess the cost-effectiveness of peripherally inserted central catheter (PICC) placements using an ultrasound and electrocardiogram-guided system versus external measurements and confirmatory chest X-rays (CXRs). MATERIALS AND METHODS: Sixty-eight guided PICC placements were performed in 63 outpatients (mean age, 43 ± 13 years; 50% male) and compared to 68 propensity score-matched PICC placements (mean age, 44 ± 13 years; 56% male) performed using external measurements by the same operators. Post-placement CXRs were used to confirm final catheter tip positioning. Cohorts were compared in terms of repositioning rates, desired tip positioning rates (in the lower third of the superior vena cava or at the cavoatrial junction), and estimated cost per PICC positioned as desired using manufacturer quotes, Medicare reimbursement rates, and hourly wages for staff time. Agreement between tip positioning according to the guided system versus CXR was also assessed. RESULTS: Guided PICC placements required less repositioning (1.5% vs 10.3%, P = .03) and resulted in more catheters positioned as desired (86.8% vs 67.6%, P = .01) than the external measurement approach. The cost per PICC positioned as desired was lower for guided placements ($318.54 vs $381.44), suggesting that the guided system was cost-effective in this clinical setting. Guided system-CXR agreement for tip position was poor (κ=0.25, P = .002) due to tips being slightly farther from the cavoatrial junction on CXR than indicated by the guided system. CONCLUSIONS: The guided PICC placement system was cost-effective in outpatients treated by a single division of interventional radiology at an academic institution.

Single-Center Retrospective Review of Radiofrequency Wire Recanalization of Refractory Central Venous Occlusions.

PURPOSE: To retrospectively review the effectiveness and safety of radiofrequency (RF) wire recanalization of refractory central venous occlusions (CVOs) and compare recurrent and nonrecurrent CVOs in terms of patient and occlusion characteristics. MATERIALS AND METHODS: Twenty CVOs were treated in 18 patients (age 40 y ± 13; 9 women) with 11 superior vena cava (SVC) or brachiocephalic vein occlusions (ie, supradiaphragmatic) and 9 inferior vena cava or iliac vein occlusions (ie, infradiaphragmatic). Indications included pain, edema, ulceration, and/or dialysis arteriovenous fistula dysfunction peripheral to the CVO(s). All patients had multiple venous thrombotic risk factors, including mechanical venous compression, endothelial injury, and/or coagulopathies. CVO traversal was first attempted with standard and advanced techniques before RF wire recanalization and followed up with computed tomographic venography and clinic visits approximately 1, 3, 6, and 12 months after treatment. RESULTS: Sixteen CVOs (80%) were successfully transversed and associated with symptom relief. One major complication occurred involving SVC perforation into the pericardial space. Primary CVO patency rate was 56% at a median follow-up of 14.1 months (interquartile range [IQR], 9.2-20.0 mo). Recurrent CVOs tended to be infradiaphragmatic (71% vs 12% for supradiaphragmatic; P = .02), longer (12.9 cm ± 10.0 vs 2.3 cm ± 1.3; P < .01), and associated with implanted venous stents, filters, or cardiac pacer/defibrillator leads (86% vs 22%; P = .01). Median time to restenosis/occlusion was 1.5 months (IQR, 1.1-6.1 mo). CONCLUSIONS: RF wire recanalization is a relatively effective and safe option for refractory CVOs. Patients with longer, infradiaphragmatic CVOs associated with indwelling devices may require closer follow-up for CVO recurrence.

Who We Are and What We Can Become: An Analysis of Professional Identity Formation in IR.

PURPOSE: To characterize the unique experiences, values, and perspectives of interventional radiology (IR) fellows. MATERIALS AND METHODS: Sixteen fellows from 4 US vascular and IR programs were interviewed within 2 months of beginning and 2-3 months following their 2015-2016 fellowships about patient interactions, training experiences, and views of IR and other specialties. Interviews were systematically analyzed for dominant themes by using constructivist grounded theory. Four interviews with 2015-2016 interventional cardiology fellows, 16 interviews with IR attending physicians, and online descriptions of IR were also analyzed for context. Themes were compared qualitatively and quantitatively. RESULTS: Interobserver agreement was good for interview themes (κ = 0.70; P < .0001). IR fellows' professional identity emerged primarily from radiologic and surgical interests, with distinct emphasis on being "innovators," "thinking differently," and "needing to adapt and advertise abilities to survive." Fellows' descriptions of patient care were more clinically focused than past interviews with attending physicians (P = .05), but clinical interests common in medical specialties were limited, and descriptions of "nonprocedural patient care" were primarily periprocedural (81%). Descriptions of the future of the field conveyed competing pressures, loose role definition, and disconnect between academic and private-practice IR. CONCLUSIONS: IR fellows share professional interests, views of their field and others, and descriptions of patient care, but there is uncertainty regarding future roles of the specialty and a need for more specific and unified definitions of nonprocedural patient care in IR.

Single-Center Experience Using AngioVac with Extracorporeal Bypass for Mechanical Thrombectomy of Atrial and Central Vein Thrombi.

The AngioVac device (AngioDynamics, Inc, Queensbury, New York), a commercially available large-diameter aspiration cannula using extracorporeal venovenous bypass, is designed to facilitate en bloc mechanical thrombectomy of massive thrombi of the central vasculature. Between February 2014 and January 2015, seven consecutive patients, each presenting with large central thrombi of the iliac veins, vena cava, right atrium, or pulmonary artery, underwent thrombectomy. Partial or complete clot abatement was achieved in all instances. All patients survived the procedure. One case was complicated by embolization of septic thrombi. At most recent follow-up, one patient had died of causes unrelated to venous thrombosis; all other patients were living (median follow-up time 8 mo). Several technical and therapeutic insights were gained from our center's early experience.

Inadvertent Arterial Placement of Central Venous Catheters: Diagnostic and Therapeutic Strategies.

BACKGROUND: Central venous catheterization (CVC) is among the most ubiquitous medical procedures. Inadvertent arterial placement of the catheter presents a challenging dilemma to the interventionalist. Treatment options include: removal and manual compression, off-label use of percutaneous closure devices and/or stent grafts, and open surgical removal. Potential sequelae include bleeding, thrombosis, stroke, limb ischemia, neurologic deficit, and death. Our aim is to evaluate the use of open and endovascular techniques for the management of iatrogenic carotid, subclavian, and brachiocephalic arterial injuries related to inadvertent arterial CVC placement. METHODS: Retrospective chart review revealed 13 patients with iatrogenic arterial injuries related to inadvertent arterial CVC placement over a 5-year period at Northwestern Memorial Hospital using Current Procedural Terminology codes and interventional radiology and vascular databases. Presenting features, radiographic diagnosis, therapeutic maneuvers, and outcomes were reviewed. RESULTS: Endovascular therapy was instituted in 10 cases with 3 requiring an adjunctive open procedure. In the endovascular therapy group, stent grafts were used in 5 patients and 4 patients were managed with percutaneous closure devices. In 1 patient, multiple embolization procedures were performed in an attempt to close a large innominate artery arteriovenous fistula (AVFs) that ultimately required sternotomy and surgical ligation for complete closure. Primary open repair was carried out in 3 patients. Two patients developed embolic stroke before therapy and removal, with 1 death reported at 36-month follow-up. Overall success rate with a single intervention was 100% (4 of 4) with closure devices, 80% (4 of 5) covered stents, 0% (0 of 1) with embolization, and 100% (3 of 3) with open intervention. Overall complication rate was 7% (1 of 13) requiring further open, invasive intervention. CONCLUSIONS: Management of carotid, subclavian, and brachiocephalic arterial injuries from attempted jugular or subclavian venous cannulation can be challenging. The risk of embolic phenomenon associated with arterial catheterization, and the noncompressible anatomic location at the base of the neck frequently prevent simple removal. We use a strategy of immediate computed tomography or magnetic resonance to facilitate the most appropriate therapy. Endovascular treatment with covered stent grants, percutaneous closure devices, and embolization offer good results when selected appropriately based on imaging evaluation. However, more complex cases with associated pseudoaneurysms and/or AVFs with larger catheters may require definitive open repair.

Ethanol embolotherapy of vascular malformations: clinical outcomes at a single center.

PURPOSE: To retrospectively evaluate the results of endovascular therapy of vascular malformations principally treated with ethanol embolization at a single center. MATERIALS AND METHODS: From May 1999 to December 2012, 46 patients (28 female, 18 male) with vascular malformations (31 venous malformations, 15 arteriovenous malformations [AVMs]) throughout the body (nine upper extremity, 31 lower extremity, and six truncal) who underwent ethanol embolization were studied and followed up. Demographic factors, clinical findings, imaging data, and patient-reported changes in symptoms were collected and analyzed. Follow-up data were obtained by office visits, repeat imaging, and telephone contact. RESULTS: Twenty-four patients (52.2%) were considered cured, 12 (26.1%) showed improvement, and 10 (21.7%) had no change or showed worsening. Similar rates of cure or improvement were seen for AVMs and venous malformations (P = 0.67). Lesion location, depth, and size were not associated with differences in outcomes (P = .87, P = .37, and P = .61, respectively). Type 1 and type 2 AVMs were cured more often than other AVM types. The overall complication rate was 24% (11 of 46 patients). Minor complications were seen in six individuals (13%), and major complications developed in five patients (11%). CONCLUSIONS: Ethanol embolization of vascular malformations produces good outcomes, with control or relief of symptoms in a majority of patients.

Cancer concepts and principles: primer for the interventional oncologist-part I.

A sophisticated understanding of the rapidly changing field of oncology, including a broad knowledge of oncologic disease and the therapies available to treat them, is fundamental to the interventional radiologist providing oncologic therapies, and is necessary to affirm interventional oncology as one of the four pillars of cancer care alongside medical, surgical, and radiation oncology. The first part of this review intends to provide a concise overview of the fundamentals of oncologic clinical trials, including trial design, methods to assess therapeutic response, common statistical analyses, and the levels of evidence provided by clinical trials.

Cancer concepts and principles: primer for the interventional oncologist-part II.

This is the second of a two-part overview of the fundamentals of oncology for interventional radiologists. The first part focused on clinical trials, basic statistics, assessment of response, and overall concepts in oncology. This second part aims to review the methods of tumor characterization; principles of the oncology specialties, including medical, surgical, radiation, and interventional oncology; and current treatment paradigms for the most common cancers encountered in interventional oncology, along with the levels of evidence that guide these treatments.

Radioembolization results in longer time-to-progression and reduced toxicity compared with chemoembolization in patients with hepatocellular carcinoma.

BACKGROUND & AIMS: Chemoembolization is one of several standards of care treatment for hepatocellular carcinoma (HCC). Radioembolization with Yttrium-90 microspheres is a novel, transarterial approach to radiation therapy. We performed a comparative effectiveness analysis of these therapies in patients with HCC. METHODS: We collected data from 463 patients who were treated with transarterial locoregional therapies (chemoembolization or radioembolization) over a 9-year period. We excluded patients who were not appropriate for comparison and analyzed data from 245 (122 who received chemoembolization and 123 who received radioembolization). Patients were followed for signs of toxicity; all underwent imaging analysis at baseline and follow-up time points. Overall survival was the primary outcome measure. Secondary outcomes included safety, response rate, and time-to-progression. Uni- and multivariate analyses were performed. RESULTS: Abdominal pain and increased transaminase activity were more frequent following chemoembolization (P < .05). There was a trend that patients treated with radioembolization had a higher response rate than with chemoembolization (49% vs 36%, respectively, P = .104). Although time-to-progression was longer following radioembolization than chemoembolization (13.3 months vs 8.4 months, respectively, P = .046), median survival times were not statistically different (20.5 months vs 17.4 months, respectively, P = .232). Among patients with intermediate-stage disease, survival was similar between groups that received chemoembolization (17.5 months) and radioembolization (17.2 months, P = .42). CONCLUSIONS: Patients with HCC treated by chemoembolization or radioembolization with Yttrium-90 microspheres had similar survival times. Radioembolization resulted in longer time-to-progression and less toxicity than chemoembolization. Post hoc analyses of sample size indicated that a randomized study with > 1000 patients would be required to establish equivalence of survival times between patients treated with these two therapies.

Fibrin cap disruption: an adjunctive technique for inferior vena cava filter retrieval.

Various adjunctive techniques have been reported for challenging inferior vena cava (IVC) filter retrievals (1-4). One particularly challenging obstacle to successful IVC filter retrieval is the formation of a radiolucent fibrin cap over the embedded apex of the IVC filter. This obstacle is a result of filter tilting that creates turbulent blood flow, which promotes fibrin cap formation. The aim of this brief report is to depict a novel technique for IVC filter retrieval: guide wire-manipulated disruption of the fibrin cap.