Intravascular US: Applications in Interventional Radiology.

Interventional radiology applications of intravascular US (IVUS) continue to expand, complementing intraprocedural angiography and providing a unique vantage from which to guide endovascular interventions. Vascular pathologic conditions become sonographically visualized rather than inferred from the planar appearance of the opacified vascular lumen. Perivascular targets become sonographically visualized rather than approximated on the basis of fluoroscopic landmarks. The authors introduce broad categories of IVUS catheters, namely radial and side-firing varieties, as well as prevailing options for each and their technical specifications. Common applications within interventional radiology are covered in a systems approach, including deep venous thrombosis, May-Thurner syndrome, nutcracker syndrome, transjugular intrahepatic portosystemic shunts, aortic interventions, peripheral arterial disease, and endovascular or perivascular biopsy. Discussions are accompanied by technical pearls from the authors, and summarized evidence where IVUS has been shown to reduce procedural time, intravascular contrast agent dose, radiation exposure, and morbidity in each space is presented. Finally, emerging applications and future directions are discussed. ©RSNA, 2022.

Peripancreatic Fluid Collections After Pancreas Transplant: Safety and Efficacy of Percutaneous Drainage.

OBJECTIVE. The purpose of this study was to evaluate the safety and efficacy of percutaneous drainage of peripancreatic fluid collections after pancreas transplant and to determine factors predicting a successful clinical outcome. MATERIALS AND METHODS. This single-center retrospective study included 28 patients who underwent percutaneous drainage for peripancreatic collections after transplant between January 2008 and December 2018. Clinical success was defined as drainage resulting in resolution of symptoms. Primary clinical success was defined as symptom resolution after the initial drainage procedure, and secondary success was defined as symptom resolution after additional drainage procedures. Operative intervention or death was considered clinical failure. Patient, collection, and procedural factors were assessed for their potential impact on the clinical outcome. RESULTS. Clinical success was achieved in 23 of 28 drainage procedures (82.1%), with primary success in 15 procedures. Of the five patients with failed drainage procedures, three required pancreatectomies, one required surgical washout, and one died from a disseminated infection. The median duration of drainage in the clinical success group was 25 days (range, 3-136 days), and patients with longer drainage periods had more successful outcomes (p = .04). Graft pancreatitis was diagnosed in five patients (17.9%) and was not associated with drainage outcome (p = .21). Collections were positive for bacterial growth in 13 patients (46.4%) and were high in amylase in 12 (42.9%). We observed drainage failure in collections with polymicrobial growth and in the presence of fistulas (p = .05 and p = .07, respectively). Patients with successful outcomes had smaller collection volumes (p = .045). No complications attributed to drainage were encountered. CONCLUSION. Percutaneous drainage is safe and effective for management of peripancreatic fluid collections after pancreas transplant.

Complex Inferior Vena Cava Filter Retrieval Complicated by Migration of Filter Fragment into the Aorta and Subsequent Distal Embolization.

In 2005, a 48-year-old man with a spinal cord injury had an inferior vena cava filter placed for recurrent deep vein thrombosis and pulmonary embolism. He was referred for filter retrieval after a computed tomography scan demonstrated caval stenosis and 2 fractured filter arms, 1 in a pulmonary artery and 1 penetrating into the retroperitoneum and impinging on the aorta. During retrieval, 1 arm was inadvertently advanced into the aorta, and embolization of the arm occurred to the left profunda femoris artery. It was subsequently retrieved. This is the first reported case to the authors' knowledge of migration and embolization of a filter fragment into the systemic arterial system.

Left upper lobe and lingula torsion after transplantation of single lung with complete major and minor fissures: A case report.

BACKGROUND: Native lung torsion is rare and torsion in a lung transplant is even rarer. CASE PRESENTATION: Here we report a case of left upper lobe (LUL) and lingula torsion in a patient with a unilateral left lung transplantation. The transplant was complicated by a graft with a short pulmonary artery cuff, which required significant vascular reconstruction and manipulation. Additionally, the graft had complete left major and minor fissures, which are documented risk factors for torsion. After 24 h postoperatively, the patient failed to wean off ventilation. The patient was worked up with bronchoscopy, a computed tomography (CT), and a CT angiogram (CTA). A CT without intravenous (IV) contrast showed the findings suggestive of torsion of the LUL and lingula and the CTA confirmed the diagnosis. Immediate re-exploration was performed for detorsion to preserve the vitality of the allograft. Following the failed detorsion, the patient had re-transplantation of the left lung with good results. CONCLUSION: Lung torsion should be watched for in patients with major risk factors like complete fissure. CT and/or CTA are effective tools to confirm the diagnosis.

Management of Indiana pouch stones through a percutaneous approach: A single center experience.

OBJECTIVE: We present our experience of the treatment of reservoir stones using a percutaneous approach in patients with Indiana pouch urinary diversions. MATERIAL AND METHODS: Patients who were treated percutaneously for Indiana pouch reservoir stones between January 2008 and December 2018 were identified from the hospital database, and their data were retrospectively analyzed. Patient charts were reviewed for stone burden, surgery details, and postoperative complications. The Indiana pouch was punctured under a direct ultrasound guidance, and a 30F sheath was placed into the pouch. A urologist removed the stones by inserting a rigid nephroscope through the sheath. A Foley catheter was left in the pouch through the percutaneous tract and opened to drainage. RESULTS: Seven patients (mean age: 47.3±14.7 years) were included. All patients were stone free after the procedure. The median stone number was 3 (range: 1-8). The mean maximum stone diameter was 24.4±4.9 mm (range: 19-33 mm). Six patients were successfully treated in one session, whereas 1 patient required two treatment sessions. The median postoperative hospital admission was 1 day (range: 1-5 days). The Foley catheters were removed after a median of 18 days (range: 10-19 days). No major complications were reported. CONCLUSION: The percutaneous approach for Indiana pouch reservoir stones treatment ensures direct and safe management without major periprocedural complications.

Communication with the exon-junction complex and activation of nonsense-mediated decay by human Upf proteins occur in the cytoplasm.

The nonsense-mediated mRNA decay (NMD) pathway rids eukaryotic cells of mRNAs with premature termination codons. There is contradictory evidence as to whether mammalian NMD is a nuclear or a cytoplasmic process. Here, we show evidence that NMD in human cells occurs primarily, if not entirely, in the cytoplasm. Polypeptides designed to inhibit interactions between NMD factors specifically impede NMD when exogenously expressed in the cytoplasm. However, restricting the polypeptides to the nucleus strongly impairs their NMD-inhibitory function, even for those intended to inhibit interactions between the exon-junction complex (EJC) and hUpf3 proteins, which localize primarily in the nucleus. NMD substrates classified based on cell fractionation assays as "nucleus associated" or "cytoplasmic" are all inhibited in the same manner. Furthermore, retention of the NMD factor hUpf1 in the nucleus strongly impairs NMD. These observations suggest that the hUpf complex communicates with the EJC and triggers NMD in the cytoplasm.