Rendezvous Technique for Advanced Pancreatic Duct Interventions.

Interventional radiology can be used to perform complex pancreatic duct (PD) interventions in cases in which PD abnormalities limit the feasibility of an endoscopic approach. A multidisciplinary approach with gastroenterology using the rendezvous technique can improve procedural success. The establishment of through-and-through access to the PD via a combined percutaneous and endoscopic approach can be used when endoscopy alone fails. In this study, 3 cases are presented in which the rendezvous technique was successfully employed to access the PD for subsequent interventions.

Multicenter assessment of augmented reality registration methods for image-guided interventions.

PURPOSE: To evaluate manual and automatic registration times and registration accuracies on HoloLens 2 for aligning a 3D CT phantom model onto a CT grid, a crucial step for intuitive 3D navigation during CT-guided interventions; to compare registration times between HoloLens 1 and 2. METHODS: Eighteen participants in various stages of clinical training across two academic centers performed registration of a 3D CT phantom model onto a CT grid using HoloLens 2. Registration times and accuracies were compared among different registration methods, clinical experience levels, and consecutive attempts. Registration times were also compared retrospectively to prior HoloLens 1 results. RESULTS: Mean aggregate manual registration times were 27.7 s, 24.3 s, and 72.8 s for one-handed gesture, two-handed gesture, and Xbox controller, respectively; mean automatic registration time was 5.3 s (ANOVA p < 0.0001). No significant difference in registration times was found among attendings, residents and fellows, and medical students (p > 0.05). Significant improvements in registration times were detected across consecutive attempts using hand gestures (p < 0.01). Compared to prior HoloLens 1 data, hand gesture registration was 81.7% faster with HoloLens 2 (p < 0.05). Registration accuracies were not significantly different across manual registration methods, measuring at 5.9 mm, 9.5 mm, and 8.6 mm with one-handed gesture, two-handed gesture, and Xbox controller, respectively (p > 0.05). CONCLUSIONS: Manual registration times decreased significantly on HoloLens 2, approaching those of automatic registration and outperforming Xbox controller registration. Fast, adaptive, and accurate registration of holographic models of cross-sectional imaging is paramount for the implementation of augmented reality-assisted 3D navigation during CT-guided interventions.

Aortic Dissection: Branched, Fenestrated, and Parallel Aortic Stent Grafts in the Ascending Aorta and Arch.

Open surgical repair of dissections and post-dissection degenerative aneurysms involving the ascending thoracic aorta and aortic arch, whether in the acute or post-repair state, is associated with high rates of morbidity and mortality. Recent advancements in minimally invasive endovascular techniques have expanded the role of thoracic endovascular aortic repair (TEVAR) for dissections and dissection-related arch pathologies. Image-guided endovascular techniques, such as in situ fenestrated grafts, chimney and/or periscope grafts, along with newly developed commercially available branched aortic devices, have allowed for an increasing number of high-risk operative candidates to undergo definitive repair of aortic arch pathology who otherwise would have been destined for non-operative management. This paper reviews the data, pre-procedural planning, and technical considerations for complex TEVAR techniques for ascending and aortic arch dissections and dissection-related aneurysms.

Diagnostic and Interventional Radiology Case Volume and Education in the Age of Pandemics: Impact Analysis and Potential Future Directions.

RATIONALE AND OBJECTIVES: To assess the immediate impact of the COVID-19 pandemic on Diagnostic and Interventional Radiology education, and to propose measures to preserve and augment trainee education during future crises. MATERIALS AND METHODS: Diagnostic Radiology (DR) studies and Interventional Radiology (IR) procedures at a single tertiary-care teaching institution between 2015 and 2020 were reviewed. DR was divided by section: body, cardiothoracic, musculoskeletal (MSK), neuroradiology, nuclear medicine, pediatrics, and women's imaging. IR was divided by procedural types: arterial, venous, lymphatic, core, neuro, pediatrics, dialysis, cancer embolization or ablation, noncancer embolization, portal hypertension, and miscellaneous. Impact on didactic education was also assessed. ANOVA, t test, and multiple comparison correction were used for analysis. RESULTS: DR and IR caseloads decreased significantly in April 2020 compared to April of the prior 5 years (both p < 0.0001). Case volumes were reduced in body (49.2%, p < 0.01), MSK (54.2%, p < 0.05), neuro (39.3%, p < 0.05), and women's imaging (75.5%, p < 0.05) in DR, and in arterial (62.6%, p < 0.01), neuro IR (57.6%, p < 0.01) and core IR (42.6%, p < 0.05) in IR. IR trainee average caseload in April 2020 decreased 51.9% compared to April of the prior 5 years (p < 0.01). Utilization of online learning increased in April. Trainees saw significant increases in overall DR didactics (31.3%, p = 0.02) and no reduction in IR didactics, all online. Twelve major national and international DR and IR meetings were canceled or postponed between March and July. CONCLUSION: Decreases in caseload and widespread cancellation of conferences have had significant impact on DR/IR training during COVID-19 restrictions. Remote learning technologies with annotated case recording, boards-style case reviews, procedural simulation and narrated live cases as well as online lectures and virtual journal clubs increased during this time. Whether remote learning can mitigate lost opportunities from in-person interactions remains uncertain. Optimizing these strategies will be important for potential future restricted learning paradigms and can also be extrapolated to augment trainee education during unrestricted times.

Correction to: Yttrium-90 Radioembolization for BCLC Stage C Hepatocellular Carcinoma Comparing Child-Pugh A Versus B7 Patients: Are the Outcomes Equivalent?

The name of one of the co-authors was slightly misspelled. Kristian Enestvedt is listed currently as "Kristian K. Enestvedt" and should be listed instead as "C. Kristian Enestvedt."

Yttrium-90 Radioembolization for BCLC Stage C Hepatocellular Carcinoma Comparing Child-Pugh A Versus B7 Patients: Are the Outcomes Equivalent?

OBJECTIVE: To evaluate yttrium-90 (Y90) radioembolization outcomes across Child-Pugh scores in patients with advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: From April 2005 to December 2018, 106 consecutive patients with BCLC Stage C HCC who underwent Y90 radioembolization were retrospectively analyzed. Exclusion criteria included additional malignancy (n = 7), death unrelated to liver disease (n = 2), metastases (n = 2), or lack of follow-up data (n = 4). Ninety-one patients were analyzed. Overall survival (OS) was calculated using the Kaplan-Meier method and compared between groups with the log-rank test. Cox regression modeling was used to evaluate the prognostic factors for survival. RESULTS: Mean age was 63 years and 85.7% were male. HCV infection was the most common etiology of liver disease (58.2%). Sixty-four (70.3%) patients were Child-Pugh A, 19 (20.9%) patients were B7, and eight (8.8%) patients were B8-9. Median OS after radioembolization was 20.2 [95% confidence interval (CI) 13.0-27.4], 6.0 (95% CI 4.4-7.6), and 5.5 (95% CI 2.5-8.5) months for Child-Pugh A, B7, and B8/9 groups, respectively (P < 0.001 for B7 vs. A; P = 0.537 for B7 vs. B8/9). The multivariable Cox regression analysis showed that Eastern Cooperative Oncology Group (ECOG) score (P < 0.001), Child-Pugh class (P = 0.005), tumor morphology pattern (P = 0.012), and Y90 delivery location (P = 0.020) were significant independent predictors of overall survival. CONCLUSIONS: Outcomes from Y90 for BCLC C HCC for Child-Pugh B7 patients were equivalent to B8/9 patients and significantly worse compared to Child-Pugh A patients. Although further research is warranted, these results suggest continued cautious patient selection for radioembolization in advanced HCC.

Evaluation and Management of Intermediate and High-Risk Pulmonary Embolism.

OBJECTIVE. The evidence regarding pulmonary embolism treatment has greatly advanced over the past 10 years, particularly in patients with right ventricular dysfunction or hemodynamic instability. Treatment options include systemic anticoagulation, systemic thrombolysis, catheter-assisted thrombus removal (mechanical with or without catheter-directed thrombolysis), and surgical embolectomy. CONCLUSION. This article will review the data available for treatment options and summarize the evidence-based guidelines on treatment of intermediate- or high-risk pulmonary embolism.

Advanced Techniques in Thoracic Endovascular Aortic Repair: Chimneys/Periscopes, Fenestrated Endografts, and Branched Devices.

Thoracic endovascular aortic repair (TEVAR) is a rapidly growing and improving technique for the management of thoracic aortic aneurysms, dissections, and traumatic aortic injury. These disease processes were previously treated exclusively by surgery, but TEVAR has substantially improved patient outcomes including reduced mortality, reduced paraplegia rate, and shorter hospital and/or intensive care unit stay compared to open surgery. TEVAR was initially isolated to the descending thoracic aorta, but the advent of advanced techniques has extended the scope to well beyond the left subclavian artery and into Zone 0. Recent techniques include chimney grafts, periscope grafts, in situ fenestrations, and physician modified grafts. In addition, commercial branched aortic devices are currently on trial and will likely vastly extend the off-the-shelf capabilities of TEVAR for aortic arch disease. This paper reviews the data, concepts, and technical aspects of current advanced TEVAR techniques, as well as ongoing clinical trials for thoracic branched aortic devices.

Antiplatelet Therapy is Associated with Stent Patency After Iliocaval Venous Stenting.

PURPOSE: To examine the effectiveness of antithrombotic medications to prevent venous stent malfunction for iliocaval occlusive disease. MATERIALS AND METHODS: A retrospective analysis was performed on 62 patients who underwent technically successful endovascular iliocaval stent placement between May 2008 and April 2017. Clinical records were reviewed for demographic information, procedure details, post-stenting antithrombotic prophylaxis and stent patency on follow-up. Stent malfunction was defined as > 50% stenosis or occlusion at follow-up. Risk factors for stent malfunction were assessed with univariable and multiple Cox proportional hazard models. RESULTS: The median follow-up period was 11.6 months (range 0.1-76.4). Overall primary and secondary cumulative patency rates at 12 months were 70.0% and 92.4%, respectively. After stent placement, 97% of patients received anticoagulation with warfarin, enoxaparin or a factor Xa inhibitor. In addition, 61% received antiplatelet prophylaxis with aspirin, clopidogrel or a combination. In multiple Cox regression analysis, post-stenting antiplatelet use remained significantly associated with primary stent patency (HR = 0.28, P = 0.022). CONCLUSION: After iliocaval venous stenting, stent patency was best predicted by concomitant antiplatelet and anticoagulation therapy rather than anticoagulation alone. This novel finding warrants further research underlying mechanisms leading to venous stent thrombosis, and has implications for optimal medical management after venous stenting.

Long-Term Toxicity after Transarterial Radioembolization with Yttrium-90 Using Resin Microspheres for Neuroendocrine Tumor Liver Metastases.

PURPOSE: To evaluate long-term effects of yttrium-90 (90Y) transarterial radioembolization (TARE) for unresectable hepatic metastases of neuroendocrine tumors (NETs). MATERIALS AND METHODS: Retrospective analysis of 93 patients (47 women, 46 men; mean age 59 y) who underwent resin-based 90Y TARE was performed. Variables associated with overall survival were analyzed using univariate and multivariate models. Changes in serologic values and imaging characteristics were assessed with long-term follow-up. RESULTS: Unilobar TARE was performed in 48 patients, and staged bilobar TARE was performed in 45 patients. In multivariate analysis, ascites (P = .002) and extrahepatic metastases (P = .038) at baseline were associated with poor survival. Among 52 patients who had > 1 year of follow-up, significant increases in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were observed; however, only 4 patients experienced grade 3 serologic toxicities. Imaging signs of cirrhosis-like morphology and portal hypertension were observed in 15 of 52 patients, more frequently in patients treated with bilobar TARE compared with unilobar TARE. Patients treated with bilobar TARE exhibited significantly increased hepatobiliary enzymes and decreased platelet count. Sustained increases in liver enzymes were observed in patients with > 4 years of follow-up. No radioembolization-related liver failure or grade 4 toxicity was observed. CONCLUSIONS: 90Y radioembolization using resin microspheres demonstrated a high safety profile for NET liver metastases, with low-grade, although sustained, long-term liver toxicity evident > 4 years after treatment. Bilobar treatment suggested a trend for treatment-related portal hypertension. Ongoing research will help define parameters for optimizing durable safety and efficacy of radioembolization in this setting.

Risk factors for stent graft thrombosis after transjugular intrahepatic portosystemic shunt creation.

BACKGROUND: To identify risk factors of stent graft thrombosis after transjugular intrahepatic portosystemic shunt (TIPS) creation. METHODS: Patients who underwent TIPS creation between June 2003 and January 2016 and with follow-up assessing stent graft patency were included (n=174). Baseline comorbidities, liver function, procedural details and follow-up liver function tests were analyzed in association with hazards of thrombosis on follow-up. Competing risk cox regression models were used considering liver transplant after TIPS creation as the competing risk variable. RESULTS: One-, 2- and 5-year primary patency rates were 94.1%, 91.7% and 78.2%, respectively. Patient age [sub-hazard ratio (sHR): 1.13; P=0.001], body mass index (BMI) <30 (sHR: 33.08; P=0.008) and a higher post-TIPS portosystemic pressure gradient (sHR: 1.14; P=0.023) were significantly associated with TIPS thrombosis in multivariate analysis. A higher rate of TIPS thrombosis was observed in those for whom the procedure was clinically unsuccessful (P=0.014). A significant increase in incidence of thrombosis was noted with increasing tertiles of post-TIPS portosystemic gradients (P value for trend=0.017). CONCLUSIONS: Older age, lower BMI and higher post-TIPS portosystemic gradients were associated with higher hazards of shunt thrombosis after TIPS creation using stent grafts. Higher rates of shunt thrombosis were seen in patients for whom TIPS creation was clinically unsuccessful. The association between TIPS thrombosis and higher post-TIPS portosystemic gradients may indicate impaired flow through the shunt, a finding which may be technical or anatomic in nature and should be assessed before procedure completion.

Expectoration of an inferior vena cava filter strut.

Inferior vena cava (IVC) filter use is widespread in patients with venous thromboembolism (VTE) and temporary contraindication to anticoagulation, though timely removal is often not performed. We report the case of an expectoration of an IVC filter strut. Review of the patient's prior imaging confirmed an infrarenal Bard G2 filter with an absent strut, which was visualised in the left lung base. The strut was presumed to have embolised to a pulmonary artery branch and eroded into an adjacent bronchus. Subsequent fluoroscopically guided filter retrieval was successful. The incidence of IVC filter fractures increases with longer dwell times. Filter fragment embolisation has resulted in major adverse events, including sudden death and cardiac tamponade. Recent evidence has suggested that retrieval of IVC filters with prolonged dwell times is feasible and safe. This report brings awareness to the range of complications with indwelling IVC filters, and highlights the importance of timely removal.

Genetics, Pregnancy, and Aortic Degeneration.

We present a case of familial thoracic aortic aneurysm and dissection (FTAAD) in a pregnant female. FTAAD is an inherited, nonsyndromic aortopathy resulting from several genetic mutations critical to aortic wall integrity have been identified. One such mutation is the myosin heavy chain gene (MYH11) which is responsible for 1-2% of all FTAAD cases. This mutation results in aortic medial degeneration, loss of elastin, and reticulin fiber fragmentation predisposing to TAAD. Aortic disease is more aggressive during pregnancy as a result of increased wall stress from hyperdynamic cardiovascular changes and estrogen-induced aortic media degeneration. Our patient was a 29-year-old G2P1 woman at 26 weeks gestation presenting with abdominal and back pain. Work-up revealed a 6.4-cm ascending aortic aneurysm with a type A dissection extending into all arch vessels, aortic coarctation at the isthmus, and a separate focal type B aortic dissection with visceral involvement. Surgical management included concomitant cesarean section with delivery of a live premature infant, tubal ligation, ascending aortic replacement with reconstruction of the arch vessels, and aortic valve resuspension. The type B dissection was managed medically without complication. This is the first reported case of aortic dissection in a patient with FTAAD/MYH11 mutation and pregnancy. This case highlights that FTAAD and pregnancy cause aortic degeneration via distinct mechanisms and that hyperdynamics of pregnancy increase aortic wall stress. Management of pregnancy associated with aortopathy requires early transfer to a tertiary center, careful investigation to identify familial aortopathy, fetal monitoring, and a multidisciplinary team approach.

Alveolar soft part sarcoma: unusual etiology of mediastinal mass in an adolescent.

Alveolar soft part sarcoma (ASPS) is a rare malignancy that usually arises in an extremity. Mediastinal involvement is uncommon, with only two reports of primary mediastinal disease and two reports of metastatic mediastinal disease in the literature, all referencing adult patients. To our knowledge, ours is the first report of ASPS presenting with a mediastinal mass in adolescence. Although ASPS is not generally included in the differential for adolescent mediastinal masses, it should be considered when clinical presentation and imaging appearance are characteristic.