Risk factors and treatment interventions associated with incomplete thrombus resolution and pulmonary hypertension after pulmonary embolism.

BACKGROUND: Residual pulmonary vascular occlusion (RPVO) affects one half of patients after a pulmonary embolism (PE). The relationship between the risk factors and therapeutic interventions for the development of RPVO and chronic thromboembolic pulmonary hypertension is unknown. METHODS: This retrospective review included PE patients within a 26-month period who had baseline and follow-up imaging studies (ie, computed tomography [CT], ventilation/perfusion scans, transthoracic echocardiography) available. We collected the incidence of RPVO, percentage of pulmonary artery occlusion (%PAO), baseline CT %PAO, most recent CT %PAO, and difference between the baseline and most recent %PAO on CT (Δ%PAO). RESULTS: A total of 354 patients had imaging reports available; 197 with CT and 315 with transthoracic echocardiography. The median follow-up time was 144 days (interquartile range [IQR], 102-186 days). RPVO was present in 38.9% of the 354 patients. The median Δ%PAO was -10.0% (IQR, -32% to -1.2%). Fewer patients with a provoked PE developed RPVO (P ≤ .01), and the initial troponin level was lower in patients who developed RPVO (P = .03). The initial thrombus was larger in the patients who received advanced intervention vs anticoagulation (baseline CT %PAO: median, 61.2%; [IQR, 27.5%-75.0%] vs median, 12.5% [IQR, 2.5%-40.0%]; P ≤ .0001). Catheter-directed thrombolysis (CDT; median Δ%PAO, -47.5%; IQR, -63.7% to -8.7%) and surgical pulmonary embolectomy (SPE; median Δ%PAO, -42.5; IQR, -68.1% to -18.7%) had the largest thrombus reduction compared with anticoagulation (P = .01). Of the 354 patients, 76 developed pulmonary hypertension; however, only 14 received pulmonary hypertension medications and 12 underwent pulmonary thromboendarterectomy. Cancer (odds ratio [OR], 1.7) and planned prolonged anticoagulation (>1 year; OR, 2.20) increased the risk of RPVO. In contrast, the risk was lower for men (OR, 0.61), patients with recent surgery (OR, 0.33), and patients treated with SPE (OR, 0.42). A larger Δ%PAO was found in men (coefficient, -8.94), patients with a lower body mass index (coefficient, -0.66), patients treated with CDT (coefficient, -18.12), and patients treated with SPE (coefficient, -21.69). A lower Δ%PAO was found in African-American patients (coefficient, 7.31). CONCLUSIONS: The use of CDT and SPE showed long-term benefit in thrombus reduction.

Predictors of endobronchial forceps utilization for inferior vena cava filter retrieval: when snare retrieval fails.

BACKGROUND: Endobronchial forceps are commonly used for complex IVC filter removal and after initial attempts at IVC filter retrieval with a snare have failed. Currently, there are no clear guidelines to help distinguish cases where primary removal should be attempted with standard snare technique or whether attempts at removal should directly be started with forceps. This study is aimed to identify clinical and imaging predictors of snare failure which necessitate conversion to endobronchial forceps. METHODS: Retrospective analysis of 543 patients who underwent IVC filter retrievals were performed at three large quaternary care centers from Jan 2015 to Jan 2022. Patient demographics and IVC filter characteristics on cross-sectional images (degree of tilt, hook embedment, and strut penetration, etc.) were reviewed. Binary multivariate logistic regression was used to identify predictors of IVC filter retrieval where snare retrieval would fail. RESULTS: Thirty seven percent of the patients (n = 203) necessitated utilization of endobronchial forceps. IVC filter hook embedment (OR:4.55; 95%CI: 1.74-11.87; p = 0.002) and strut penetration (OR: 56.46; 95% CI 20.2-157.7; p = 0.001) were predictors of snare failure. In contrast, total dwell time, BMI, and degree of filter tilt were not associated with snare failure. Intraprocedural conversion from snare to endobronchial forceps was significantly associated with increased contrast volume, radiation dose, and total procedure times (p < 0.05). CONCLUSION: IVC filter hook embedment and strut penetration were predictors of snare retrieval failure. Intraprocedural conversion from snare to endobronchial forceps increased contrast volume, radiation dose, and total procedure time. When either hook embedment or strut penetration is present on pre-procedural cross-sectional images, IVC filter retrieval should be initiated using endobronchial forceps. LEVEL OF EVIDENCE: Level 3, large multicenter retrospective cohort.

New Developments in Image-Guided Percutaneous Irreversible Electroporation of Solid Tumors.

PURPOSE OF REVIEW: This review will describe the various applications, benefits, risks, and approaches of conventional irreversible electroporation (IRE), as well as highlight the new technological developments of this procedure along with their clinical applications. RECENT FINDINGS: Minimally invasive image-guided percutaneous IRE ablation has emerged as a newer, non-thermal ablation technique for tumors in the solid organs, particularly within the liver, pancreas, kidney, and prostate. IRE allows for ablation near heat-sensitive structures, including major blood vessels and nerves, and is not susceptible to the heat sink effect. However, it is limited by certain requirements, such as the need for precise parallel placement of at least two probes with a maximum inter-probe distance of 2.5 cm to reduce the risk of arching phenomenon, the requirement for general anesthesia with muscle relaxant, and the need for cardiac synchronization. However, new technological advancements in the ablation system and image guidance tools have been introduced to improve the efficiency and efficacy of IRE. IRE is a safe and effective treatment option for solid tumor ablation within the liver, pancreas, kidney, and prostate. Compared with other ablation techniques, IRE has several advantages, such as the absence of heat sink effect and minimal injury to blood vessels and bile ducts while activating the immune system. Novel techniques such as H-FIRE, needle placement systems, and robotics have enhanced the accuracy and performance in placement of IRE probes. IRE can be especially beneficial when combined with chemotherapy, immunomodulation, and immunotherapy.

The Role of Mechanical Thrombectomy for Acute Massive Pulmonary Embolism in a Patient With Unilateral Lung Transplant and Atrial Septal Defect.

PURPOSE: The risk of thromboembolic disease is high in patients with lung transplantation and is associated with significant morbidity and mortality with single healthy transplanted lung. We present a case involving successful endovascular management of life-threatening acute massive pulmonary embolism (PE) in a patient with single lung transplant and atrial septal defect (ASD). CASE REPORT: A 65-year-old man with a history of interstitial lung disease status post single left orthotopic lung transplant in 2012 presented with acute massive PE and clot burden in the pulmonary arteries of the transplanted left lung. Severe right heart dysfunction, hemodynamic instability, and requirement for vasopressors persisted post systemic thrombolytic therapy. As a result, the patient underwent successful endovascular mechanical thrombectomy with immediate improvement in oxygen saturation and hemodynamic status. The procedure was performed without adverse outcomes or paradoxical embolization despite the presence of ASD. The right heart dysfunction resolved, the patient was extubated the next day, and was discharged to home 2 days post procedure. CONCLUSIONS: Endovascular mechanical thrombectomy was safely used to treat acute massive PE in a single transplanted lung in the presence of ASD. CLINICAL IMPACT: Endovascular mechanical thrombectomy could be safely utilized to treat patients with lung transplant and acute massive or submassive pulmonary embolism. However, safely of mechanical thrombectomy should be determined in case-based scenarios and based on time interval from transplantation to when the thrombectomy is required.

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors.

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.

Percutaneous Chest Tube for Pleural Effusion and Pneumothorax.

Chest tubes are placed in the pleural space to evacuate abnormal fluid or air accumulations. Various types and sizes of chest tubes are available. Imaging including ultrasound, computed tomography, and fluoroscopy should be used to guide chest tube placement. Understanding the anatomy of the pleural space, along with the etiology and classification of pleural space disease, can help optimize chest tube management. This article will review the indications, contraindications, techniques, and postprocedure follow-up of chest tube placement as well as discuss the management and prevention of complications.

Percutaneous Management of Benign Biliary Strictures.

Benign biliary strictures are often due to a variety of etiologies, most of which are iatrogenic. Clinical presentation can vary from asymptomatic disease with elevated liver enzymes to obstructive jaundice and recurrent cholangitis. Diagnostic imaging methods, such as ultrasound, multidetector computed tomography, and magnetic resonance imaging (cholangiopancreatography), are used to identify stricture location, extent, and possible source of biliary obstruction. The management of benign biliary strictures requires a multidisciplinary team approach and include endoscopic, percutaneous, and surgical interventions. Percutaneous biliary interventions provide an alternative diagnostic and therapeutic approach, especially in patients who are not amenable to endoscopic evaluation. This review provides an overview of benign biliary strictures and percutaneous management by interventional radiologists. Diagnostic evaluation with percutaneous transhepatic cholangiography and treatment options, including biliary drainage, balloon dilation, retrievable/biodegradable stents, and other innovative minimally invasive options, are discussed.

Imaging Health and Radiology Care of Transgender Patients: A Call to Build Evidence-Based Best Practices.

Transgender people have a gender identity that differs from their natal sex and experience many forms of discrimination, including within the health care field. Although transgender patients only comprise 0.6% of the adult US population, they frequently require imaging evaluation. Few published articles provide data-driven research on optimizing education of the radiology care team and delivery of inclusive and respectful imaging care to this vulnerable population; existing data suggest prior areas of success and prior areas of failure. Here, we offer specific recommendations on how radiology care team members can better serve transgender patients and begin generating much needed evidence-based best practices to improve their imaging health and care.

Retrospective Analysis of the Safety and Outcomes of Percutaneous Radiologic Gastrostomy in Obese vs Nonobese Patients.

BACKGROUND: The purpose of this study is to compare the safety and outcomes of percutaneous radiologic gastrostomy (PRG) in obese vs nonobese patients. METHODS: This is an institutional review board-approved retrospective study of 109 patients (male:female, 68:41; mean age, 64.7 years; range, 21-94 years) who underwent PRG with or without gastropexy at a single academic medical center between 2015 and 2018. Body mass index (BMI) of ≥30 kg/m2 was defined as obese. Patient demographics, indications, technical success, intraoperative variables, and major/minor complications were analyzed. Major and minor complications occurring within 30 days of the procedure were recorded and categorized based on the Society of Interventional Radiology Quality Improvement guidelines. RESULTS: Of 109 patients included in the study, 22.9% (n = 25) of patients were obese (average BMI, 34.6 kg/m2 ; range, 30-50). Overall technical success in the obese and nonobese groups was 100% each. In the obese vs nonobese group, major and minor complications were not significantly different. There were also no significant differences in procedure time, fluoroscopy time, or contrast volume. However, mean peak skin dose was significantly increased in the obese group vs nonobese group (190.3 ± 224.2 vs 59.1 ± 71.1 mGy; P < .0001). CONCLUSION: PRG is a safe procedure in obese patients with similar technical success, major and minor complication rates, procedure time, fluoroscopy time, and contrast volume. However, PRG is associated with increased radiation dose with obese patients; therefore, optimal methods of radiation protection should be utilized.

Nonoperative Management of Blunt Splenic Trauma: Outcomes of Gelfoam Embolization of the Splenic Artery.

CONTEXT: Nonoperative management (NOM) is the standard of care in hemodynamically stable trauma patients with blunt splenic injury. Gelfoam splenic artery embolization (SAE) is a treatment option used in trauma patients. AIMS: The primary aim of this study was to retrospectively examine the use and outcomes of Gelfoam SAE in adult patients with blunt splenic injury. SETTINGS AND DESIGN: One hundred and thirty-two adult patients with blunt splenic injury admitted to a Level 1 trauma center between January 2014 and December 2015 were included in the study. Patients treated with Gelfoam SAE, NOM, and splenectomies were reviewed. Descriptive statistics including patient age, Glasgow Coma Scale, Injury Severity Score (ISS), hospital days, Intensive Care Unit (ICU) days, splenic grade, and amount of blood products administered were recorded. Complications, defined as any additional factors that contributed to the patient's overall length of hospital stay, were compared between the three groups. Technical aspects of Gelfoam SAE and associated complications were reviewed. SUBJECTS AND METHODS: Gelfoam SAE was performed in 25 (18.9%) of the 132 patients. Gelfoam SAE patients had fewer ICU days compared with those patients who had a splenectomy or NOM. There was no statistical difference in complications between patients who underwent Gelfoam SAE and those who did not. Patients who underwent Gelfoam SAE tended to have fewer complications including deep venous thrombosis's, PE, and infections and yielded no complications in 64% of the Gelfoam group. STATISTICAL ANALYSIS: Statistical analysis included descriptives, ANOVA, and nonparametric tests as appropriate. CONCLUSION: Gelfoam SAE can be used for blunt splenic injury for intermediate ISS and splenic grade as it reduced hospital and ICU days.

Clinical Efficacy, Safety, and Feasibility of Using Video Glasses during Interventional Radiologic Procedures: A Randomized Trial.

PURPOSE: To evaluate the clinical efficacy, safety, and feasibility of implementing video glasses in a variety of interventional radiologic (IR) procedures. MATERIALS AND METHODS: Between August 2012 and August 2013, 83 patients undergoing outpatient IR procedures were randomized to a control group (n = 44) or an experimental group outfitted with video glasses (n = 39). State-Trait Anxiety Inventory (STAI) scores, sedation and analgesia doses, mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), pain scores, and procedure times were obtained. Complications and adverse events related to the use of video glasses were recorded. Postprocedural staff surveys and patient satisfaction surveys were completed. RESULTS: Women had greater preprocedural anxiety than men (P = .0056), and patients undergoing vascular interventions had greater preprocedural anxiety than those undergoing nonvascular interventions (P = .0396). When assessed after the procedure, patients who wore video glasses had significantly reduced levels of anxiety (-7.7 vs -4.4, respectively; P = .0335) and average MAP (-6.3 vs 2.1, respectively; P = .0486) compared with control patients. There was no significant difference in amount of sedation and analgesia, HR, RR, pain score, or procedure time between groups. No significant adverse events related to the use of video glasses were observed. Postprocedural surveys showed that video glasses were not distracting and did not interfere or pose a safety issue during procedures. Patients enjoyed using the video glasses and would use them again for a future procedure. CONCLUSIONS: Video glasses can be safely implemented during IR procedures to reduce anxiety and improve a patient's overall experience.

Clinical outcomes of inferior vena cava filter placement in patients with renal vein anomalies.

BACKGROUND: To investigate the clinical outcomes in patients with renal vein anomalies who undergo inferior vena cava (IVC) filter placement. METHODS: Contrast-enhanced computed tomography images of 410 patients who underwent IVC filter placement were retrospectively reviewed to detect renal vein anomalies. Clinical outcomes involving de novo pulmonary embolism and worsening of renal function were compared between patients with the location of filters placed in relation to the anomalous renal veins versus not in relation to any renal veins. RESULTS: A total of 97 (23.7%) renal vein anomalies were identified: 62 (15.1%) multiple right renal veins, 23 (5.6%) circumaortic left renal veins, 10 (2.4%) retroaortic left renal veins, and 2 (0.5%) accessory left renal veins. Frequency of de novo pulmonary embolism in patients with circumaortic left renal veins who had filters placed at or in between the 2 left renal veins was not significantly different from patients who underwent infra- or suprarenal filter placement (5.9% [1/17] vs. 3.1% [12/387]; P = 0.433). The frequency of patients who had a >25% decrease in estimated glomerular filtration rate after IVC filter placement was not significantly different whether the filter was placed in an infrarenal location or at or above the level of the anomalous renal veins (11.0% [37/335] vs. 17.6% [6/34]; P = 0.261). CONCLUSIONS: Clinical outcomes involving the frequency of de novo pulmonary embolism and worsening of renal function are not dependent on location of IVC filter placement in patients with renal vein anomalies.

Incidence and complications of accidental cannulation of retroperitoneal veins during venography for inferior vena cava filter placement.

BACKGROUND: The purpose of this study was to evaluate the incidence and complications of accidental cannulation of retroperitoneal veins during venography for inferior vena cava (IVC) filter placement. METHODS: In total, 641 patients who underwent IVC filter placement were retrospectively reviewed. Incidence of accidental cannulation of retroperitoneal veins during venography (using 633 sheaths and 18 catheters, including 11 pigtail type and 7 end-hole-type catheters), along with the associated complications, were evaluated. RESULTS: The overall frequency of accidental cannulation of retroperitoneal veins was 5.4% (35 of 651) via venous approaches: 5.8% (24 of 411) via a right femoral approach, 3.9% (5 of 129) via a left femoral approach, and 5.4% (6 of 111) via a jugular approach. The most frequent veins cannulated were the ascending lumbar veins (4.6%, 25 of 540) via a femoral approach, and the median sacral vein (3.6%, 4 of 111) via a jugular approach. No significant difference in the frequency of accidental cannulation was observed between venography through sheaths and catheters (5.4% [n = 34] vs. 5.6% [n = 1; using an end-hole-type catheter]; P = 1.000). Injuries to 5 veins (0.8%), including 3 ascending lumbar veins, were observed. Inadvertent filter placement within the right ascending lumbar vein was observed in 1 patient (0.2%). CONCLUSIONS: Accidental cannulation of retroperitoneal veins during venography for IVC filter placement is an infrequent occurrence, and in this patient series did not result in negative clinical outcomes. However, operators should be aware of the risk of accidental cannulation to prevent avoidable complications such as venous injury or filter misplacement.

Magnetic resonance imaging of pineal region tumours.

OBJECTIVES: Pineal lesions can present as a heterogeneous collection of benign and malignant disease conditions. Pineal lesions include germ cell tumours, neoplasms arising from the pineal parenchyma, as well as other pineal region masses. METHODS: A variety of cases of pineal lesions are presented. The important clinical features and typical imaging findings of each pineal lesion are described with emphasis on their morphological appearance and signal intensity characteristics on magnetic resonance imaging (MRI). CONCLUSION: Knowledge of the imaging characteristics and clinical features of varying pineal lesions can assist in narrowing the differential diagnosis for more accurate and rational therapeutic planning. TEACHING POINTS: • Pineal parenchymal tumours show an "explosion" of normal pineal calcifications towards the periphery. • Pineoblastomas often have restricted diffusion, with apparent diffusion coefficient (ADC) values lower than germinomas. • Pineal teratomas and pineal lipomas display fat signal characteristics and fat saturation on MRI. • Pineal lesions in patients with known malignancy should raise suspicion of metastatic involvement. • Pineal cysts and arachnoid cysts show MRI signal characteristics similar to cerebrospinal fluid (CSF).

Substituent effects on the assembly of helical cyanine dye aggregates in the minor groove of a DNA template.

Double-helical DNA was used as a template for the assembly of helical cyanine dye aggregates. The aggregates consist of cofacial dimers aligned end-to-end in the minor groove of the DNA. The effect of methoxy or fluoro substituents placed on the periphery of the cyanine dye heterocycles on aggregation both in water and on the DNA template was studied by UV-vis and circular dichroism spectroscopy. Methoxy groups were found to be stronger promoters of aggregation than fluoro, and a dimethoxy dye exhibited a higher propensity to aggregate compared with an unsymmetrical methoxy/fluoro dye. Semiempirical calculations supported the experimental observation of methoxy substitution favoring aggregation. These results indicate that dispersion and hydrophobic effects contribute more to dimerization/aggregation than do electron donor-acceptor effects.