I. Brennan

Delayed Growth in Incidental Pancreatic Cysts: Are the Current American College of Radiology Recommendations for Follow-up Appropriate?

PURPOSE To evaluate growth kinetics of asymptomatic small (<2 cm) incidental pancreatic cysts and to assess potential implications of these in the context of current American College of Radiology recommendations. MATERIALS AND METHODS This institutional review board-approved HIPAA-compliant retrospective study with waiver of informed consent included patients with asymptomatic small incidental pancreatic cysts (diameter, 5-20 mm) with two or more magnetic resonance (MR) examinations performed at least 6 months apart at a tertiary institution. The largest cyst dimension was measured on T2-weighted single-shot fast spin-echo images by one of six radiologists (1-3 years of experience) who were trained to measure pancreatic cysts in a similar manner. All analysis was conducted at the patient level by choosing the cyst that exhibited the greatest growth over the follow-up period in each patient. Fisher exact, χ(2), and Kruskal-Wallis tests and analysis of variance were used to test correlation between cyst characteristics and growth. RESULTS A total of 259 patients (mean age, 65 years ± 11 [standard deviation], male-to-female ratio, 42:58) with 370 asymptomatic small incidental pancreatic cysts were included. At presentation, median cyst size was 9.4 mm (interquartile range [IQR], 7.0-12.2 mm), and 64 patients (25%; 95% confidence interval [CI]: 20, 30) had septations. The median imaging follow-up period was 2.2 years (IQR, 1.2-3.9 years; range, 0.5-11.0 years), with a median of three MR examinations (IQR, two to four examinations) per patient. In 171 (66%; 95% CI: 60, 72) of the 259 patients, cysts remained stable; in 18 (7%; 95% CI: 4, 11), cysts shrank; and in 70 (27%; 95% CI: 22, 33), cysts grew (median total growth and median annual growth of 4.8 mm and 2.3 mm/y, respectively). Age, cyst size, and cyst septation at presentation were not predictive of growth. Overall, 29 (11%), 16 (6%), and four (1.5%) of the cysts increased in size after 1, 2, and 3 years of initial stability, respectively. Of the 18 patients who underwent pancreatic surgery, only one patient with an intraductal papillary mucinous neoplasm had high-grade dysplasia. One patient developed pancreatic adenocarcinoma remotely at the location of the pancreatic cyst diagnosed 11 months prior. CONCLUSION In the majority of patients, asymptomatic small incidental pancreatic cysts remained stable during a median follow-up period of 2.2 years; however, in 27% of patients, cysts increased in size over time, with 11% growing after an initial 1-year period of stability. Current American College of Radiology recommendations to discontinue imaging follow-up after 1 year of stability may need to be reevaluated.

Adrenal venous sampling: promises and pitfalls

Purpose of reviewTo describe the current indications for adrenal vein sampling (AVS), variability in institutional protocols for performing the procedure, shortage of expert interventional radiologists trained in this procedure, pitfalls in technique and strategies to improve success. A major emphasis of the review will focus on the interpretation of the AVS results. Recent findingsPublished protocols for performance of the AVS procedure and variability in the diagnostic criteria differentiating aldosterone-producing adenoma from bilateral adrenal hyperplasia vary significantly. Inability to catheterize the right adrenal vein is the major reason for technical failure of AVS. Preplanning computed tomography, stat intraprocedural cortisol levels and cone-beam computed tomography are helpful in identifying the right adrenal vein. The administration of adrenocorticotropic hormone stimulation during AVS varies significantly between different studies. SummaryMore interested interventional radiologists need to acquire the necessary technical expertise for AVS due to increased demand for the procedure, which is the diagnostic reference standard for primary aldosteronism. Unresolved issues include variability in the AVS procedure protocol, use of adrenocorticotropic hormone stimulation and standardization of the interpretation of the results. Despite all these variables, many different approaches still appear to be clinically successful, as indicated by the extensive published reports.

Superselective splenic artery embolization for the management of splenic laceration following colonoscopy

Splenic injury is a rare complication following colonoscopy with fewer than 100 reported cases worldwide to date. We describe a case of splenic laceration presenting 5 days following diagnostic colonoscopy. Although hemodynamically stable, active contrast extravasation on contrast-enhanced multidetector computed tomography predicted likely failure of conservative management. Splenic artery angiography confirmed active extravasation from the lower splenic pole and the patient was successfully treated with super selective coil embolization of a lower pole splenic artery branch. This is the eighth reported case of endovascular treatment of splenic injury following colonoscopy. To our knowledge, however, superselective splenic artery embolization has not been previously reported to treat this rare endoscopic complication.

Imaging Features Following Transarterial Chemoembolization and Radiofrequency Ablation of Hepatocellular Carcinoma

Transarterial chemoembolization and radiofrequency ablation are currently the most widely used modalities in the minimally invasive treatment of unresectable hepatocellular carcinoma. This article briefly summarizes the minimally invasive therapeutic options in the management of hepatocellular carcinoma focusing on transarterial chemoembolization and radiofrequency ablation and describes normal post-treatment imaging appearances. Imaging features of post-treatment local tumor recurrence as well as procedure-related complications following these interventions have also been described.

Preparation for Percutaneous Ablation Procedures

Percutaneous tumor ablation is now commonly used to treat a wide range of focal tumors. Patients eligible for ablation often have complex medical problems that preclude them from receiving other treatments. The interventional radiologist needs to perform a careful clinical evaluation of each patient before the procedure to determine which patients are suitable candidates for treatment and to identify patients who may be at a higher risk for complications. The clinical consultation also provides an opportunity to prepare the patient for the ablation and to appropriately plan the procedure. In this article, we discuss key components of the consultation and concepts regarding patient evaluation and preparation for a tumor ablation procedure.

Utility of liver biopsy in predicting clinical outcomes after percutaneous angioplasty for hepatic venous obstruction in liver transplant patients

AIM To determine utility of transplant liver biopsy in evaluating efficacy of percutaneous transluminal angioplasty (PTA) for hepatic venous obstruction (HVOO). METHODS Adult liver transplant patients treated with PTA for HVOO (2003-2013) at a single institution were reviewed for pre/post-PTA imaging findings, manometry (gradient with right atrium), presence of HVOO on pre-PTA and post-PTA early and late biopsy (EB and LB, < or > 60 d after PTA), and clinical outcome, defined as good (no clinical issues, non-HVOO-related death) or poor (surgical correction, recurrent HVOO, or HVOO-related death). RESULTS Fifteen patients meeting inclusion criteria underwent 21 PTA, 658 ± 1293 d after transplant. In procedures with pre-PTA biopsy (n = 19), no difference was seen between pre-PTA gradient in 13/19 procedures with HVOO on biopsy and 6/19 procedures without HVOO (8 ± 2.4 mmHg vs 6.8 ± 4.3 mmHg; P = 0.35). Post-PTA, 10/21 livers had EB (29 ± 21 d) and 9/21 livers had LB (153 ± 81 d). On clinical follow-up (392 ± 773 d), HVOO on LB resulted in poor outcomes and absence of HVOO on LB resulted good outcomes. Patients with HVOO on EB (3/7 good, 4/7 poor) and no HVOO on EB (2/3 good, 1/3 poor) had mixed outcomes. CONCLUSION Negative liver biopsy greater than 60 d after PTA accurately identifies patients with good clinical outcomes.

Portal vein thrombosis following percutaneous transhepatic cholangiography-An unusual presentation of Prothrombin (Factor II) gene mutation

Portal vein thrombosis is an uncommonly reported complication of percutaneous transhepatic cholangiography (PTC). A thorough review of the available literature shows no reported cases. In this case, a 29 year old female presented on two separate occasions with portal vein thrombosis following PTC without drain placement. This unusual complication of image guided percutaneous biliary access is unreported in the literature and prompted evaluation of the patients coagulation parameters. A thrombophilia screen demonstrated a mutation in the Prothrombin (Factor II) gene. A thorough literature review shows no reported cases of portal vein thrombosis following percutaneous biliary access, is an unusual complication, and should raise suspicion of an underlying pro-coagulant state.