Interventional Radiology Management of Adult Liver Transplant Complications.

Liver transplant remains the definitive therapy for patients with end-stage liver disease. Outcomes have continued to improve, in part owing to interventions used to treat posttransplant complications involving the hepatic arteries, portal vein, hepatic veins or inferior vena cava (IVC), and biliary system. Significant hepatic artery stenosis can be treated with angioplasty or stent placement to prevent thrombosis and biliary ischemic complications. Hepatic arterioportal fistula and hepatic artery pseudoaneurysm are rare complications that can often be treated with endovascular means. Treatment of hepatic artery thrombosis can have mixed results. Portal vein stenosis can be treated with venoplasty or more commonly stent placement. The rarer portal vein thrombosis can also be treated with endovascular techniques. Hepatic venous outflow stenosis of the hepatic veins or IVC is amenable to venoplasty or stent placement. Complications of the bile ducts are the most encountered complication after liver transplant. When not amenable to endoscopic intervention, biliary stricture, bile leak, and ischemic cholangiopathy can be treated with percutaneous transhepatic cholangiography with biliary drainage and other interventions. New techniques have further improved care for these patients. Transsplenic portal vein recanalization has improved transplant candidacy for patients with chronic portal vein thrombosis. Spontaneous splenorenal shunt and splenic artery steal syndrome (nonocclusive hepatic artery hypoperfusion syndrome) remain complicated topics, and the role of endovascular embolization is developing. When patients have recurrence of cirrhosis after transplant, most commonly due to viral hepatitis, transjugular intrahepatic portosystemic shunt (TIPS) may be required to treat symptoms of portal hypertension. Online supplemental material is available for this article. ©RSNA, 2022.

Interventional Management of Acquired Lymphatic Disorders.

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ©RSNA, 2022.

Transsplenic Portal System Catheterization: Review of Current Indications and Techniques.

Multiple diseases of the portal system require effective portal vein access for endovascular management. While percutaneous transhepatic and transjugular approaches remain the standard methods of portal vein access, transsplenic access (TSA) has gained recognition as an effective and safe technique to access the portal system in patients with contraindications to traditional approaches. Recently, the utility of percutaneous TSA has grown, with described treatments including recanalization of chronic portal vein occlusion, placement of stents for portal vein stenosis, portal vein embolization of the liver, embolization of gastric varices, placement of complicated transjugular intrahepatic portosystemic shunts, and interventions after liver transplant. The authors provide a review of percutaneous TSA, including indications, a summary of related portal vein diseases, and the different techniques used for access and closure. In addition, an imaging-based review of technical considerations of TSA interventions is presented, with a review of potential procedural complications. With technical success rates that mirror or rival the standard methods and reported low rates of major complications, TSA can be a safe and effective option in clinical scenarios where traditional approaches are not feasible. ©RSNA, 2022.

Venous Anatomy and Collateral Pathways of the Pelvis: An Angiographic Review.

The pelvic venous system is complex, with the potential for numerous pathways of collateralization. Owing to stenosis or occlusion, both thrombotic and nonthrombotic entities in the pelvis may necessitate alternate routes of venous return. Although the pelvic venous anatomy and collateral pathways may demonstrate structural variability, a number of predictable paths often can be demonstrated on the basis of the given disease and the level of obstruction. Several general categories of collateral pathways have been described. These pathway categories include the deep pathway, which is composed of the lumbar and sacral veins and vertebral venous plexuses; the superficial pathway, which is composed of the circumflex and epigastric vessels; various iliofemoral collateral pathways; the intermediate pathway, which is composed of the gonadal veins and the ovarian and uterine plexuses; and portosystemic pathways. The pelvic venous anatomy has been described in detail in cadaveric and anatomic studies, with the aforementioned collateral pathways depicted on CT and MR images in several imaging studies. A comprehensive review of the native pelvic venous anatomy and collateralized pelvic venous anatomy based on angiographic features has yet to be provided. Knowledge of the diseases involving a number of specific pelvic veins is of clinical importance to interventional and diagnostic radiologists and surgeons. The ability to accurately identify common collateral patterns by using multiple imaging modalities, with accurate anatomic descriptions, may assist in delineating underlying obstructive hemodynamics and diagnosing specific occlusive disease entities. ©RSNA, 2022.

Nuclear Medicine and Molecular Imaging in Nodal Staging and Surveillance of Ocular Melanoma: Case Reports and Review of the Literature.

Ocular melanoma (OM) is a rare noncutaneous malignancy and consists of 2 different subtypes based on the anatomic location in the eye: uveal melanoma and conjunctival melanoma. Like cutaneous melanoma, OM benefits from nuclear medicine and molecular imaging in nodal staging and clinical management. Through the illustration of 2 distinctive cases, we aim to demonstrate the complementary roles of standard lymphoscintigraphy, advanced SPECT/CT, 18F-FDG PET/CT, and 18F-FDG PET/MRI in accurate nodal staging and surveillance of OM. We also review the epidemiology, existing staging guidelines, and management of uveal melanoma and conjunctival melanoma.

Imaging findings of pelvic venous insufficiency in patients with postural orthostatic tachycardia syndrome.

OBJECTIVES: Some patients with postural orthostatic tachycardia syndrome (POTS) demonstrate improved dysautonomic symptoms following treatment for pelvic venous insufficiency (PVI). This study assessed the prevalence of significant left common iliac vein (LCIV) compression in POTS patients. METHODS: Radiologists retrospectively reviewed CT images of pelvic veins for 216 women (191 with POTS and 25 age-comparable controls).Quantitative vascular analysis identified percent-diameter compression of the LCIV by the right common iliac artery. Significant LCIV compression was defined as >50%. RESULTS: Significant LCIV compression was found in 69% (131/191) of females with POTS versus 40% (10/25) in controls. The hypothesis that venous compression and presence of POTS are independent was rejected (p = .005). CONCLUSIONS: Significant LCIV compression was noted in a majority of female POTS patients, suggesting that incidence of iliac venous obstruction may be higher than the general population. Patients with POTS and symptoms of PVI may benefit from assessment for venous outflow obstruction.

Ergonomics in IR.

Ergonomic research in the field of interventional radiology remains limited. Existing literature suggests that operators are at increased risk for work-related musculoskeletal disorders related to the use of lead garments and incomplete knowledge of ergonomic principles. Data from existing surgical literature suggest that musculoskeletal disorders may contribute to physician burnout and female operators are at a higher risk of developing musculoskeletal disorders. This review article aims to summarize the existing ergonomic challenges faced by interventional radiologists, reiterate existing solutions to these challenges, and highlight the need for further ergonomic research in multiple areas, including burnout and gender.

Abdominal Imaging Manifestations of Recreational Drug Use.

Recreational drug use is a burgeoning health issue worldwide, with a variety of presenting symptoms and complications. These complications can be secondary to the toxic effects of the drug itself, drug impurities, and nonsterile injection. The abdominal radiologist is likely to encounter patients who use drugs recreationally and may be responsible for recognizing and reporting these acute conditions, which in some cases can be life threatening. Because these patients often present with an altered mental state and may deny or withhold information on drug use, the underlying cause may be difficult to determine. The most commonly used drugs worldwide include cocaine, cannabinoids, opioids, and amphetamines and their derivatives. Complications of use of these drugs that can be seen at abdominopelvic CT can involve multiple organ systems, including the soft tissue and gastrointestinal, genitourinary, vascular, and musculoskeletal systems. A diverse range of abdominal complications associated with these drugs can be seen at imaging, including disseminated infections, gastrointestinal ischemia, and visceral infarction. Radiologists should be familiar with the imaging findings of these complications to accurately diagnose these entities and help guide workup and patient treatment. ©RSNA, 2020.

Dose reduction using digital fluoroscopy versus digital subtraction angiography in endovascular aneurysm repair: A prospective randomized trial.

OBJECTIVE: Endovascular aneurysm repair (EVAR) can result in high radiation dose to patients and operators. This prospective randomized study aimed to assess whether patient radiation dose sustained during EVAR could be decreased by predominantly using digital fluoroscopy (DF) vs the standard technique using digital subtraction angiography (DSA). METHODS: Between February 2011 and June 2017, patients with EVAR of infrarenal abdominal aortic aneurysms were prospectively enrolled and randomly assigned to a standard treatment DSA cohort or a DF cohort in which two or fewer DSA acquisitions were allowed for confirmatory imaging. Primary end points included dose-area product (DAP) and cumulative air kerma. Secondary end points included technical success and conversion to DSA standard treatment (if DF was inadequate for visualization). RESULTS: For all 43 patients enrolled (26 in the DF cohort, 17 in the DSA cohort), technical success was 100%. Of the 26 DF patients, 5 (19%) required conversion to the DSA cohort. In an intention-to-treat analysis, mean DAP was significantly lower in the DF cohort than in the DSA cohort (132 vs 174 Gy·cm2; P = .04). When patients were separated by number of DSA acquisitions (two or fewer vs three or more), mean DAP decreased 41% (109 vs 185 Gy·cm2; P = .005) and cumulative air kerma decreased 40% (578 vs 964 mGy; P = .004). CONCLUSIONS: In most patients (81%), DF or limited DSA was adequate for visualization during EVAR. In both intention-to-treat DF and limited-DSA cohorts, mean DAP was significantly decreased. If image quality allows, a DF-only or limited-DSA approach to EVAR decreases radiation dose.

Minimum Clinically Important Difference: Current Trends in the Orthopaedic Literature, Part II: Lower Extremity: A Systematic Review.

BACKGROUND: The minimum clinically important difference (MCID) attempts to define the patient's experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of the MCID calculation, so as to help practitioners to understand and utilize the MCID and to guide future efforts to calculate the MCID. In Part I of this review, we sampled the orthopaedic literature in relation to the upper extremity. In this part, Part II, of the review, we will focus on the lower-extremity literature. METHODS: A review was conducted of the 2014 to 2016 MCID-related publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery. Only clinical science articles utilizing patient-reported outcome measures (PROMs) were included in the analysis. A keyword search was then performed to identify articles that used the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. The MCID utilization in the selected articles was characterized and was recorded. RESULTS: The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 79 (61.2%) of the 129 articles were related to the lower extremity; of these, 11 (13.9%) independently calculated the MCID values and 68 (86.1%) used previously published MCID values as a gauge of their own results. The MCID values were calculated or were considered for 31 PROMs, of which 24 were specific to the lower extremity. Eleven different methods were used to calculate the MCID. The MCID had a wide range of values for the same questionnaires, for instance, 5.8 to 31.3 points for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). CONCLUSIONS: There are more than twice as many PROMs for the lower extremity (24) than for the upper extremity (11), confirming that the determination of useful MCID values is, in part, hampered by the proliferation of PROMs in the field of orthopaedics. The difference between significance and clinical importance needs to be further clarified. For instance, the common use of determining sample size with the MCID and comparing group means with the MCID implies that a significant result will also be clinically important. Further, the study of the MCID would benefit from consensus agreement on relevant terminology and the appropriate usage of the MCID determining equations. CLINICAL RELEVANCE: MCID is increasingly used as a measure of patients' improvement. However, MCID does not yet adequately capture the clinical importance of patients' improvement.