Percutaneous Placement of Permanent Metallic Stents in the Cystic Duct to Treat Obstructive Cholecystitis.

This report presents a series of five patients unsuitable for surgery who had nonretrievable self-expanding metallic stents deployed along the cystic duct as treatment for benign and malignant causes of gallbladder obstruction. Techniques are described for draining cholecystitis, removing gallstones, bypassing gallbladder obstructions, and inserting metallic stents across the cystic duct to restore permanent antegrade gallbladder drainage in acute and chronic cholecystitis. Symptoms resolved in all cases, and stents remained patent for as long as 22 months. This procedure may be an effective alternative to cholecystectomy or long-term gallbladder drainage for patients in inoperable condition.

Part 1: CT characterisation of pancreatic neoplasms: a pictorial essay.

The pancreas is a site of origin of a diverse range of benign and malignant tumours, and these are frequently detected, diagnosed and staged with computed tomography (CT). Knowledge of the typical appearance of these neoplasms as well as the features of locoregional invasion is fundamental for all general and abdominal radiologists. This pictorial essay aims to outline the characteristic CT appearances of the spectrum of pancreatic neoplasms, as well as important demographic and clinical information that aids diagnosis. The second article in this series addresses common mimics of pancreatic neoplasia.

Part 2: CT characterisation of pancreatic neoplasm: tumour mimics.

There are numerous pancreatic and peripancreatic conditions that can mimic pancreatic neoplasms. Many of these can be confidently diagnosed on computed tomography (CT), while others will require further imaging. Knowledge of these tumour mimics is important to avoid misclassification of benign conditions as malignant and to avoid unnecessary surgery. Mimics can be grouped as parenchymal, vascular, biliary and peripancreatic. These are discussed and illustrated in this review.

Percutaneous cystic duct stent placement in the treatment of acute cholecystitis.

Percutaneous cholecystostomy is well established as a temporising treatment option in selected patients presenting with acute cholecystitis. However, some patients who undergo cholecystostomy will have persistent discharge, which precludes catheter removal, or may not be medically suitable for future cholecystectomy. In these circumstances, percutaneous cystic duct stenting isa novel treatment option. It may delay or avoid the need for cholecystectomy, and thereby provide definitive treatment in a subset of patients who have acute cholecystitis and a high anaesthetic risk or limited life expectancy. Current application has been limited largely to patients with pre-existing malignant common bile duct strictures, but there is potential for the application to be broadened to include other subsets of patients. In this paper, we describe the technique used for percutaneous cystic duct stenting in a patient and report on its effectiveness. We also explore the technical considerations and consider the application of the procedure on other groups of patients.

Infected (mycotic) aneurysms: spectrum of imaging appearances and management.

Infected aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries, and visceral arteries are involved in descending order of frequency. Staphylococcus and Streptococcus species are the most common causative pathogens. Early clinical diagnosis of infected aneurysms is challenging owing to their protean manifestations. Clinically apparent infected aneurysms are often at an advanced stage of development or are associated with complications, such as rupture. Nontreatment or delayed treatment of infected aneurysms often has a poor outcome, with high morbidity and mortality from fulminant sepsis or hemorrhage. Current state-of-the-art imaging modalities, such as multidetector computed tomography and magnetic resonance imaging, have replaced conventional angiography as minimally invasive techniques for detection of infected aneurysms in clinically suspected cases, as well as characterization of infected aneurysms and vascular mapping for treatment planning in confirmed cases. Doppler ultrasonography allows noninvasive assessment for infected aneurysms in the peripheral arteries. Imaging features of infected aneurysms include a lobulated vascular mass, an indistinct irregular arterial wall, perianeurysmal edema, and a perianeurysmal soft-tissue mass. Perianeurysmal gas, aneurysmal thrombosis, aneurysmal wall calcification, and disrupted arterial calcification at the site of the infected aneurysm are uncommon findings. Imaging-guided endovascular stent-graft repair and embolotherapy can be performed in select cases instead of open surgery. Familiarity with the imaging appearances of infected aneurysms should alert the radiologist to the diagnosis and permit timely treatment, which may include endovascular techniques.

'Benign' hepatic portal venous gas.

The presence of portal venous gas within the hepatic parenchyma is usually associated with a guarded prognosis and a mortality rate approaching 75%. However, there are infrequent causes of portal venous gas not associated with dire clinical outcomes. We describe three patients who made uneventful clinical recoveries after presenting with clinical and imaging manifestations of ischaemic bowel and hepatic portal venous gas, two of which had distended but non-necrotic bowel at laparotomy.

Percutaneous and endovascular embolization of ruptured hepatic artery aneurysm.

A 72-year-old woman presented with an intraperitoneal hemorrhage from a ruptured intrahepatic artery aneurysm, with an associated pseudoaneurysm developing a high-flow arteriovenous fistula. Persistent coagulopathy and a median arcuate ligament stenosis of the celiac axis further complicated endovascular management. Aneurysm thrombosis required percutaneous embolization with coils, a removable core guidewire and polyvinyl alcohol particles.

Unusual clinical manifestations of the Nutcracker Syndrome.

The Nutcracker Syndrome, caused by compression of the left renal vein as it passes in a tight angle between the aorta and the superior mesenteric artery, usually presents with unexplained haematuria localized to the left ureteric orifice. We report on a series of cases where compression of the left renal vein caused prominent left-gonadal-vein reflux, which in turn resulted in lower-limb varices and varicocele formation.

Prospective assessment of magnetic resonance cholangiopancreatography for noninvasive imaging of the biliary tree.

BACKGROUND: Traditionally, ERCP has been the only reliable method for imaging the biliary tree, but it is invasive and carries a risk of complications. Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive method for imaging the biliary tree. The aim of this study was to prospectively assess the accuracy of MRCP in a large number of patients. METHODS: Consecutive patients referred to a teaching hospital for ERCP were eligible for study entry. MRCP was performed within 24 hours before ERCP. MRCP findings were compared with ERCP findings or, when the initial ERCP was unsuccessful, with results of repeat ERCP, percutaneous transhepatic cholangiography, or surgery. RESULTS: One hundred forty-six patients underwent 149 ERCP/MRCP procedures, of which 129 were evaluable with successful MRCP and ERCP or an ERCP-equivalent study. Diagnoses included choledocholithiasis in 46 and biliary stricture in 12 patients. The sensitivity, specificity, positive, and negative predictive values for MRCP in the diagnosis of choledocholithiasis were 97.9%, 89.0%, 83.6%, and 98.6%, respectively. All 12 strictures were diagnosed by MRCP (sensitivity 100%, specificity 99.1%). CONCLUSIONS: MRCP is an accurate, noninvasive alternative to ERCP for imaging the biliary tree. Choledocholithiasis and biliary strictures can be reliably diagnosed or excluded by MRCP. MRCP should be used increasingly in patients with suspected biliary obstruction to select those who require a therapeutic procedure.