Mirizzi syndrome

Opinion statement Mirizzi syndrome is an important complication of gallstone disease. If not recognized preoperatively, it can result in significant morbidity and mortality. Preoperative diagnosis may be difficult despite the availability of multiple imaging modalities. Ul-trasonography (US), CT, and magnetic resonance cholangiopancreatography (MRCP) are common initial tests for suspected Mirizzi syndrome. Typical findings on US suggestive of Mirizzi syndrome are a shrunken gallbladder, impacted stone(s) in the cystic duct, a dilated intrahepatic tree, and common hepatic duct with a normal-sized common bile duct. The main role of CT is to differentiate Mirizzi syndrome from a malignancy in the area of porta hepatis or in the liver. MRI and MRCP are increasingly playing an important role and have the additional advantage of showing the extent of inflammation around the gallbladder that can help in the differentiation of Mirizzi syndrome from other gallbladder pathologies such as gallbladder malignancy. Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in the diagnosis of Mirizzi syndrome. It delineates the cause, level, and extent of biliary obstruction, as well as ductal abnormalities, including fistula. ERCP also offers a variety of therapeutic options, such as stone extraction and biliary stent placement. Percutaneous cholangiogram can provide information similar to ERCP; however, ERCP has an additional advantage of identifying a low-lying cystic duct that may be missed on percutaneous cholangiogram. Wire-guided intraductal US can provide high-resolution images of the biliary tract and adjacent structures. Treatment is primarily surgical. Open surgery is the current standard for managing patients with Mirizzi syndrome. Good short-and long-term results with low mortality and morbidity have been reported with open surgical management. Laparoscopic management is contraindicated in many patients because of the increased risk of morbidity and mortality associated with this approach. Endoscopic treatment may serve as an alternative in patients who are poor surgical candidates, such as elderly patients or those with multiple comorbidities. Endoscopic treatment also can serve as a temporizing measure to provide biliary drainage in preparation for an elective surgery.     

Water permeability,hybrid layer long-term integrity and reaction mechanism of a two-step adhesive system

Objectives

Our aim was to investigate the reaction mechanism of formation of the hybrid layer by a HEMA-containing self-etch adhesive and to study fluid filtration, contact angle and interfacial ultrastructure by SEM following a 1 year ageing period.

Methods

Acidic behaviour and chemical interactions between Silorane System Adhesive and dentine were studied by potentiometric titrations, atomic absorption spectroscopy and infrared spectroscopy. The hydrophilicity of the adhesive was evaluated using the sessile drop method and dentine permeability by hydraulic conductance. The morphological study of the dentine/adhesive system interface was conducted using SEM.

Results

The Silorane System Adhesive behaved as a multi-acid with several different pK_a values. When the adhesive was in contact with dentine, the acid was progressively consumed and calcium ions were released. The acrylate substituted phosphonate bound strongly to apatite crystals. The polyacrylic acid copolymer reacted with calcium ions and formed an interpenetrating polymer network (IPN). Water contact angle measurements showed rapid spreading on primer (angles reached 15° at 30 s) and larger contact angles when the Silorane bonding layer was added (from over 60° to 44°). A thick, homogeneous hybrid layer was observed both initially and after 1 year of ageing, with a corresponding hydraulic conductance of −48.50% initially and −52.07% at 12 months.

Conclusion

The Silorane System Adhesive is capable of both dissolving calcium ions and binding to apatite surfaces. The results showed the hydrophilicity of the adhesive, which formed an IPN-like hybrid layer that conserved adequate impermeability over a 1-year period.     

Endovascular Treatment of a Left Carotid Artery "Bowtie" Pseudoaneurysm with a Covered Wallgraft Stent

The authors present an unusual case of a young male patient with a large left common carotid artery pseudoaneurysm in a shape similar to that of a bowtie treated with a covered Wallgraft. The Wallgraft is a covered stent originally designed to be used in the treatment of tracheobronchial fistula and peripheral arterial applications. The favorable outcome of this case illustrates its endovascular application in nonsurgical traumatic injuries of the carotid artery.