Lumen-apposing metals stents in advanced endoscopic ultrasound-guided interventions: novel applications, potential complications and radiologic assessment.

Endoscopic ultrasound (EUS)-guided drainage procedures are an increasingly utilized minimally invasive alternative to percutaneous or surgical management strategies, having been shown to decrease recovery time, cost, and duration of hospital stay. The current mainstay of EUS-guided drainage procedures is in pancreatic and peripancreatic collections in pancreatitis. Recent technological advancements and the development of specialized stents have allowed for novel applications in a growing variety of clinical scenarios, including biliary obstruction, cholecystitis and gastrointestinal obstruction. An overview is provided of standard EUS-guided lumen-apposing metal stent (LAMS) management in pancreatic collections, including the expected radiologic findings and appropriate post-treatment sequelae. Relevant parameters to report include presence of a walled-off collection, collection contents, proximity of the target collection to the gastrointestinal lumen, intervening vascular structures or vascular malformations, and presence of regional cystic structures. Novel stent applications in biliary and gastrointestinal drainage are summarized and examples are provided, including choledochoduodenostomy in biliary obstruction, cholecystogastrostomy in cholecystitis, and jejunogastrostomy in focal gastrointestinal obstruction. Finally, a pictorial review of imaging findings of complications including perforation, hemorrhage, displacement, occlusion, migration and mistargeting is provided. Minimally invasive EUS-guided endoluminal stenting is utilized in a growing variety of clinical applications. Radiologist familiarity with common and novel applications of EUS-guided stenting is invaluable in determining suitability for endoscopic management, evaluating treatment response and identifying potential complications.

The yield of CT pulmonary angiograms to exclude acute pulmonary embolism.

There is accumulating evidence regarding the overuse of computed tomography pulmonary angiography (CTPA) to exclude pulmonary embolism (PE). We evaluated the yield of CTPA studies performed at our tertiary care hospital between April 2008 and March 2010 for emergency patients (ED), inpatients (INPT), and intensive care unit inpatients (ICU). For each patient group, we also compared CTPA positivity rates among the following: daytime and on-call studies, 1 year before and after institution of an Emergency Radiology division, interpreting thoracic and non-thoracic radiologists, and individual emergency physicians. Patients with a history of PE and indeterminate studies were excluded. The diagnosis of PE was based on the radiology report. D-dimer values obtained within 24 h prior to CTPA were recorded. A total of 3,571/4,757 CTPA studies satisfied the inclusion criteria. The fraction of positive studies was 252/1,677 (15.0 %) ED, 255/1,548 (16.5 %) INPT, and 62/346 (17.9 %) ICU. There was no difference in yield between patient groups, daytime vs. on-call studies, before vs. after instituting an emergency radiology division, and thoracic vs. non-thoracic radiologists (p > 0.05). For individual emergency physicians, the mean CTPA positivity rate was 15.4 % but varied considerably (σ = 8.5 %, range, 0-38.5 %). In comparison to other recent studies, our yield of ED CTPA is relatively high but varied widely among individual emergency physicians. While the reasons for such differences require further investigation, our results reinforce the importance of a strong clinical assessment in the work-up of suspected PE.