Innovative methods of biliary tract diagnosis: intraductal ultrasound and tissue acquisition

Echoendoscopes

Advances in echoendoscopes and their processors have significantly expanded the role of EUS and its clinical applications.The diagnostic and therapeutic capabilities of EUS continue to evolve and improve. EUS has made a large impact on patient care but comes with significant startup and maintenance costs. As improved technology continues to enhance image resolution while decreasing the size of EUS processors, use of endosonography will become more widespread. EUS will continue to be a vital part of patient care and complement currently available cross-sectional imaging.

Imaging and interventions in hilar cholangiocarcinoma: A review

Hilar cholangiocarcinoma is a common malignant tumor of the biliary tree. It has poor prognosis with very low 5-year survival rates. Various imaging modalities are available for detection and staging of the hilar cholangiocarcinoma. Although ultrasonography is the initial investigation of choice, imaging with contrast enhanced computed tomography scan or magnetic resonance imaging is needed prior to management. Surgery is curative wherever possible. Radiological interventions play a role in operable patients in the form of biliary drainage and/or portal vein embolization. In inoperable cases, palliative interventions include biliary drainage, biliary stenting and intra-biliary palliative treatment techniques. Complete knowledge of application of various imaging modalities available and about the possible radiological interventions is important for a radiologist to play a critical role in appropriate management of such patients.We review the various imaging techniques and appearances of hilar cholangiocarcinoma and the possible radiological interventions.

Advances in diagnosis and treatment of hilar cholangiocarcinoma -- a review

Hilar cholangiocarcinoma (HC) is a rare tumor that causes devastating disease. In the late stages, this carcinoma primarily invades the portal vein and metastasizes to the hepatic lobes; it is associated with a poor prognosis. HC is diagnosed by its clinical manifestation and results of imaging techniques such as ultrasound, computed tomography, magnetic resonance cholangiopancreatography, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography. Preoperative hepatic bile drainage can improve symptoms associated with insufficient liver and kidney function, coagulopathy, and jaundice. Surgical margin-negative (R0) resection, including major liver resection, is the most effective and potentially curative treatment for HC. If the tumor is not resected, then liver transplantation with adjuvant management can improve survival. We conducted a systematic review of developments in imaging studies and major surgical hepatectomy for HC with positive outcomes regarding quality of life.

Intraductal ultrasonography combined with percutaneous transhepatic cholangioscopy for the preoperative evaluation of longitudinal tumor extent in hilar cholangiocarcinoma

BACKGROUND AND AIM

In hilar cholangiocarcinoma, an accurate assessment of preoperative resectability is important to optimize surgical resection. We investigated the accuracy of the combination of intraductal ultrasonography (IDUS) and percutaneous transhepatic cholangioscopy (PTCS) for evaluating longitudinal extent in hilar cholangiocarcinoma.

METHODS

Patients diagnosed with hilar cholangiocarcinoma underwent multidetector computed tomography (MDCT) and magnetic resonance cholangiography (MRC) for tumor staging and Bismuth type. Percutaneous transhepatic biliary drainage was performed at the left or right bile duct of the liver section that was anticipated to be preserved in the surgical treatment. After tract dilation, PTCS with cholangioscope-directed biopsy and IDUS were sequentially performed to evaluate Bismuth type. Surgical treatment was executed according to tumor staging and longitudinal tumor extent. Postoperative histological Bismuth types were compared to preoperative Bismuth types based on MDCT, MRC, PTCS with biopsy, and IDUS.

RESULTS

From June 2006 to November 2008, 25 patients with hilar cholangiocarcinoma were enrolled, with 20 of these patients evaluable. The accuracy of MDCT, MRC, PTCS with biopsy, and IDUS for the evaluation of Bismuth type was 80%, 84.2%, 90%, and 85.0%, respectively, in 20 patients, and 82.4%, 82.4%, 94.1%, and 88.2%, respectively, in 18 patients with Bismuth type IIIa, IIIb, or IV cancer. The accuracy of the combination of IDUS and PTCS with biopsy was 95% in 20 patients, and 100% in 18 with Bismuth type IIIa, IIIb, or IV cancer.

CONCLUSIONS

The combination of IDUS and PTCS with biopsy was highly accurate for assessing Bismuth type and may help in the identification of an optimal surgical plan for the treatment of hilar cholangiocarcinoma, especially in Bismuth type IIIa, IIIb, or IV.

Intraductal ultrasonography (IDUS) for the diagnosis of biliopancreatic diseases

Intraductal ultrasonography (IDUS) is an imaging modality having unique characteristics and suitable for imaging of a narrow ductal cavity, its wall and the neighbouring structures. As IDUS uses high-frequency ultrasound (12-30MHz), its image quality is very high within approximately 2-cm range of radius. The bile duct and the pancreatic duct, therefore, are good targets for the assessment by IDUS. Biliopancreatic IDUS is mainly performed through the papilla of Vater in the same session as endoscopic retrograde cholangiopancreatography (ERCP). Biliary IDUS is possible through the percutaneous transhepatic route as well. Not many comparative studies on biliopancreatic IDUS have been published. Gallbladder IDUS as well as most pancreatic IDUS are still at the level of clinical research. Constant delineation of Oddi's sphincter with the improvement of instruments will expand the use of IDUS for the assessment of the papilla of Vater lesions.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

Several advances in diagnosis, treatment and palliation of cholangiocarcinoma (CC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. CC is a relatively rare tumor and the main risk factors are: chronic inflammation, genetic predisposition and congenital abnormalities of the biliary tree. While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down. The only curative treatment for CC is surgical resection with negative margins. Liver transplantation has been proposed only for selected patients with hilar CC that cannot be resected who have no metastatic disease after a period of neoadjuvant chemo-radiation therapy. Magnetic resonance imaging/magnetic resonance cholangiopancreatography, positron emission tomography scan, endoscopic ultrasound and computed tomography scans are the most frequently used modalities for diagnosis and tumor staging. Adjuvant therapy, palliative chemotherapy and radiotherapy have been relatively ineffective for inoperable CC. For most of these patients biliary stenting provides effective palliation. Photodynamic therapy is an emerging palliative treatment that seems to provide pain relief, improve biliary patency and increase survival. The clinical utility of other emerging therapies such as transarterial chemoembolization, hepatic arterial chemoinfusion and high intensity intraductal ultrasound needs further study.

Advances in the endoscopic management of patients with pancreatic and biliary malignancies

Major advances in endoscopic techniques to diagnose and manage pancreatic biliary diseases have fundamentally changed the approach to these difficult clinical challenges. The diagnosis of benign and malignant pancreatic-biliary diseases is much more readily obtained through a combination of cross-sectional imaging and endoscopic procedures. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) are the most important endoscopic tools for imaging and accessing the pancreatic biliary system. The review summarizes the major imaging methods for providing a diagnosis of bile duct malignancy, including ERCP, transhepatic cholangiography (THC), and magnetic resonance cholangiopancreatography (MRCP). High quality image examples of cholangiocarcinoma are provided. EUS has provided a new imaging modality for the detection of pancreatic and biliary malignancy. EUS is particularly sensitive for the detection of early pancreatic malignancy. Furthermore, EUS excels at the guidance of fine needle aspiration of pancreatic lesions. Diagnostic tissue acquisition for cholangiocarcinoma remains an important challenge. The endoscopic therapy for pancreatic-biliary malignancy involves the use of stenting which relieves the biliary obstruction commonly seen in these patients.

Endoscopic techniques to diagnose and manage biliary tumors

Malignancies of the bile duct are often suspected in patients with abnormal serum hepatic enzyme levels and obstruction of the biliary system. Although cross-sectional imaging can provide evidence for biliary obstruction and a malignancy arising from the bile duct, a definitive diagnosis is often obtained through the use of endoscopic procedures. Endoscopic retrograde cholangiopancreatography (ERCP), the most commonly performed procedure for cholangiocarcinoma, can provide a tissue diagnosis through brush cytology of the bile duct. Relief from biliary obstruction can be provided with temporary plastic stenting or permanent metal stenting. Photodynamic therapy guided by ERCP may provide improved palliation from biliary obstruction in the future. Endoscopic ultrasonography complements the role of ERCP and may provide a tissue diagnosis through fine-needle aspiration and staging through ultrasound imaging. High-resolution ultrasound images can provide detailed information regarding the relationship between a mass and the bile duct wall. Despite these advances in endoscopic techniques and imaging of the bile duct, a tissue diagnosis often remains elusive in many patients. In the future, molecular markers will be employed to improve the sensitivity for the detection of malignancy in bile duct samples obtained through brushing, aspiration, and biopsy.

The impact of tissue sampling on endoscopy efficiency

Much of the time spent in gastrointestinal endoscopy is devoted to tissue sampling. For this reason, efforts to facilitate tissue diagnosis can greatly influence the overall efficiency of endoscopy. This overview reviews the steps involved in tissue sampling and highlights potential ways to achieve increased efficiency in tissue sampling. Both potential improvements in process and innovations in technology are considered.