Assessment of hepatic artery invasion by bile duct cancer using intraductal ultrasonography

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Endoscopic Perspective in Cholangiocarcinoma Diagnostic Process

Cholangiocarcinoma is a malignancy arising from the epithelial lining of the intrahepatic or extrahepatic biliary tract. Timely diagnosis is challenging due to its silent clinical course. As reliable laboratory markers are lacking, diagnostic imaging plays a pivotal role. While cross-sectional imaging studies are usually conclusive for intrahepatic lesions, endoscopy plays an essential role in cases of extrahepatic tumors. Rational utilization of different diagnostic methods based on available evidence is needed. This article focuses on the diagnostic role of advanced biliary endoscopy, including endoscopic retrograde cholangiopancreatography, cholangioscopy, endoscopic ultrasonography, and intraductal sonography.

Asia-Pacific consensus recommendations for endoscopic and interventional management of hilar cholangiocarcinoma

Hilar cholangiocarcinoma (HCCA) is one of the most common types of hepatobiliary cancers reported in the world including Asia-Pacific region. Early HCCA may be completely asymptomatic. When significant hilar obstruction develops, the patient presents with jaundice, pale stools, dark urine, pruritus, abdominal pain, and sometimes fever. Because no single test can establish the definite diagnosis then, a combination of many investigations such as tumor markers, tissue acquisition, computed tomography scan, magnetic resonance imaging/magnetic resonance cholangiopancreatography, endoscopic ultrasonography/intraductal ultrasonography, and advanced cholangioscopy is required. Surgery is the only curative treatment. Unfortunately, the majority of HCCA has a poor prognosis due to their advanced stage on presentation. Although there is no survival advantage, inoperable HCCA managed by palliative drainage may benefit from symptomatic improvement. Currently, there are three techniques of biliary drainage which include endoscopic, percutaneous, and surgical approaches. For nonsurgical approaches, stent is the most preferred device and there are two types of stents i.e. plastic and metal. Type of stent and number of stent for HCCA biliary drainage are subjected to debate because the decision is made under many grounds i.e. volume of liver drainage, life expectancy, expertise of the facility, etc. Recently, radio-frequency ablation and photodynamic therapy are promising techniques that may extend drainage patency. Through a review in the literature and regional data, the Asia-Pacific Working Group for hepatobiliary cancers has developed statements to assist clinicians in diagnosing and managing of HCCA. After voting anonymously using modified Delphi method, all final statements were determined for the level of evidence quality and strength of recommendation.

Comprehensive review of the diagnosis and treatment of biliary tract cancer 2012. Part I: diagnosis-clinical staging and pathology

Biliary tract cancers (gallbladder cancer, intra- and extra-hepatic cholangiocarcinoma, and selected periampullary cancers) accounted for 12,760 new cases of cancer in the USA in 2010. These tumors have a dismal prognosis with most patients presenting with advanced disease. Early, accurate diagnosis is essential, both for potential cure where possible and for optimal palliative therapy in all others. This review examines the currently available and emerging technologies for diagnosis and treatment of this group of diseases.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension.

Discrimination between sclerosing cholangitis-associated autoimmune pancreatitis and primary sclerosing cholangitis, cancer using intraductal ultrasonography

BACKGROUND AND AIM

Differentiation of sclerosing cholangitis-associated autoimmune pancreatitis (SC-AIP), primary sclerosing cholangitis (PSC) and cancer of the hilar part of the bile duct (CHB) has been challenging. The aim of the present study was to evaluate characteristic intraductal ultrasonography (IDUS) features that could be used to discriminate SC-AIP from PSC and CHB.

METHODS

Six patients with SC-AIP, 10 patients with PSC and 12 patients with CHB were identified. We reviewed the following bile duct features observed using IDUS to determine their usefulness for differentiating SC-AIP from PSC and CHB: presence of symmetrical wall thickness, wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar.

RESULTS

IDUS results (SC-AIP, PSC, CHB) were as follows: wall thickness (mm), 3.7±0.9, 2.6 ±0.9, 2.8±0.0.6; presence of symmetrical wall thickness, 100% (6/6), 20% (2/10), 8.3% (1/12); presence of homogeneous internal foci, 100% (6/6), 10% (1/10), 8.3% (1/12); and presence of lateral mucosal lesions continuous to the hilar, 83.3% (5/6), 40%(4/10), 25% (3/12). Symmetrical wall thickness of the bile duct, homogeneous internal foci and lateral mucosal lesions continuous to the hilar were detected significantly more often among the patients with SC-PSC than among the patients with PSC or CHB (P<0.05).

CONCLUSIONS

IDUS findings, such as symmetrical wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar can facilitate the differential diagnosis of SC-AIP from PSC and CHB.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are rare malignancies that arise from the biliary epithelium. Intrahepatic CCAs usually present as mass lesions that are asymptomatic or cause nonspecific systemic symptoms such as fatigue, fever, and weight loss. Hilar and extrahepatic tumors most commonly present with jaundice, though cholangitis also can be seen. Tumor markers such as carbohydrate antigen 19-9 and carcinoembryonic antigen have been used to diagnose CCA, but these are nonspecific and may be elevated in infection, inflammation, or any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) has been used for the diagnosis and management of CCA for many years. This article summarizes the data regarding the application of ERCP in the diagnosis and management of CCA.

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.

Diagnostic approaches for cholangiocarcinoma

Cholangiocarcinomas arise from the epithelial cells of the bile ducts and are associated with poor prognosis. Despite new diagnostic approaches, the definite diagnosis of this malignancy continues to be challenging. Cholangiocarcinomas often grow longitudinally along the bile duct rather than in a radial direction. Thus, large tumor masses are frequently absent and imaging techniques, including ultrasound, CT, and MRI have only limited sensitivity. Tissue collection during endoscopic (ERCP) and/or percutaneous transhepatic (PTC) procedures are usually used to confirm a definitive diagnosis of cholangiocarcinoma. However, forceps biopsy and brush cytology provide positive results for malignancy in about only 50% of patients. Percutaneous and peroral cholangioscopy using fiber-optic techniques were therefore developed for direct visualization of the biliary tree, yielding additional information about endoscopic appearance and tumor extension, as well as a guided biopsy acquistion. Finally, endoscopic ultrasonography (EUS) complements endoscopic and percutaneous approaches and may provide a tissue diagnosis of tumors in the biliary region through fine-needle aspiration. In the future, new techniques allowing for early detection, including molecular markers, should be developed to improve the diagnostic sensitivity in this increasing tumor entity.

Intraductal US in the assessment of tumor involvement to the orifice of the cystic duct by malignant biliary obstruction

BACKGROUND

Tumor involvement to the orifice of the cystic duct (OCD) is a risk factor for cholecystitis after metallic stent (MS) placement.

OBJECTIVE

ERCP and intraductal US (IDUS) were used to assess tumor involvement to the OCD.

DESIGN

A prospective consecutive study.

SETTING

The University of Tokyo Hospital, Japan.

PATIENTS AND INTERVENTIONS

Between January 2003 and May 2007, 34 patients with resectable malignant biliary obstruction underwent an ERCP and an IDUS before preoperative biliary drainage.

MAIN OUTCOME MEASUREMENTS

ERCP and IDUS findings were confirmed via a histopathologic analysis of surgical specimens.

RESULTS

An ERCP showed that the cystic duct was opacified in 22 of 34 patients (64.7%). Eight patients were diagnosed with OCD tumor involvement. In the remaining 12 patients, tumor involvement was impossible to evaluate via an ERCP. An IDUS identified tumor involvement to the OCD in all 34 patients. Tumor involvement to the OCD was diagnosed in 12 patients, including 4 patients with previously negative results during an ERCP. Tumor involvement was confirmed by histopathology of surgical specimens. The sensitivity and specificity of detection were 66.7% (8/12) and 63.6% (14/22), respectively, via ERCP, and 100% (12/12) and 100% (22/22), respectively, via IDUS.

LIMITATION

The small sample size.

CONCLUSIONS

IDUS, in addition to ERCP, provides an accurate evaluation of tumor involvement to the OCD in patients with malignant biliary obstruction.

Diagnosis of biliary tract and ampullary carcinomas

Diagnostic methods for biliary tract carcinoma and the efficacy of these methods are discussed. Neither definite methods for early diagnosis nor specific markers are available in this disease. When this disease is suspected on the basis of clinical symptoms and risk factors, hemato-biochemical examination and abdominal ultrasonography are performed and, where appropriate, enhanced computed tomography (CT) and/or magnetic resonance cholangiopancreatography (MRCP) is carried out. Diagnoses of extrahepatic bile duct cancer and ampullary carcinoma are often made based on the presence of obstructive jaundice. Although rare, abdominal pain and pyrexia, as well as abnormal findings of the hepatobiliary system detected by hemato-biochemical examination, serve as a clue to making a diagnosis of these diseases. On the other hand, the early diagnosis of gallbladder cancer is scarcely possible on the basis of clinical symptoms, so when this cancer is found with the onset of abdominal pain and jaundice, it is already advanced at the time of detection, thus making a cure difficult. When gallbladder cancer is suspected, enhanced CT is carried out. Multidetector computed tomography (MDCT), in particular — one of the methods of enhanced CT — is useful for decision of surgical criteria, because MDCT shows findings such as localization and extension of the tumor, and the presence or absence of remote metastasis. Procedures such as magnetic resonance imaging, endoscopic ultrasonography, bile duct biopsy, and cholangioscopy should be carried out taking into account indications for these procedures in individual patients. However, direct biliary tract imaging is necessary for making a precise diagnosis of the horizontal extension of bile duct cancer.

Evaluation of normal bile duct and cholangitis by intraductal ultrasonography

BACKGROUND

The intraductal ultrasonographic findings of normal bile duct and cholangitis were examined.

METHODS

We studied 9 autopsy cases and evaluated the clinical records of 76 patients who had been subjected to papillotomy for bile duct stones removal retrospectively.

RESULT

In vitro study: Under a low pressure, the bile duct wall was thick, and the inner surface and outer contour were irregular. The wall became thinner, and the inner surface and outer contour became smooth as the pressure was increased. The thickness was 0.68 +/- 0.12 mm (mean +/- SD) all along the duct at all pressure, and 0.55 +/- 0.12 mm at a pressure above 15 cm H(2)O. The internal echo was homogenous regardless of the internal pressure used. In vivo study: We could evaluate in 70 patients (92.1%). The wall was 1.30 +/- 0.77 mm thick. There was no relationship between the severity of cholangitis and the wall thickness. The irregular inner surface, heterogeneous internal echo, and irregular outer contour correlated with the severity of cholangitis.

CONCLUSION

The normal bile duct wall was between 0.31 and 0.79 mm thick, the inner and outer surfaces were smooth, and internal echo was homogenous. An irregular inner surface, heterogeneous internal echo and an irregular outer contour were important findings of severe cholangitis.

Role of radiology in the treatment of malignant hilar biliary strictures 1: Review of the literature

Malignant strictures of the biliary tree are an uncommon cause of obstructive jaundice. There are a number of pathological subtypes, but tumours in this region tend to have similar clinical and diagnostic features and therapeutic and prognostic implications. We review the published literature on this topic discussing diagnostic modalities and treatment options with a focus on radiological intervention. Diagnosis currently is best achieved using a range of procedures. Direct cholangiography remains the gold standard in delineating anatomy, but the invasiveness of this procedure limits its use as a purely diagnostic tool. Magnetic resonance technology, in particular magnetic resonance cholangiopancreatography, has an increasing role as accessibility is improved. Treatment of these tumours is difficult. Surgical resection and palliative biliary enteric bypass are the most common methods used with endoscopic and percutaneous therapies reserved for palliating patients not fit for surgery. There is little firm evidence to suggest that any one palliative modality is superior. Interventional radiology is particularly suitable for palliative management of difficult and expansive lesions as the anatomy can preclude easy access by surgical or endoscopic techniques. Good palliative results with minimal mortality and morbidity can be achieved with percutaneous stenting.

[Diagnosis of biliary tract carcinoma]

There are several diagnostic tools available in the diagnosis of bile duct cancer. Tumors of the middle and distal part of the extrahepatic bile duct are accessible to endosonography. Endoscopic retrograde cholangiopancreatography (ERC) and percutaneous transhepatic cholangiography (PTC) are the most invasive procedures for diagnosis of bile duct cancer. However, they offer the opportunity to obtain material for cytological or histological investigation. Moreover, bile flow can be assured by inserting endoprostheses during the procedure. Cholangioscopy and/or intraductal ultrasonography can be performed during ERC. They confer to the diagnosis of a malignant bile duct tumor and are the most accurate methods to diagnose the extent of longitudinal spread. Magnetic resonance imaging-cholangiography is an efficient diagnostic procedure which should be used first, if the bile duct tumor is located in the hilar region.

Evaluation of indeterminate bile duct strictures by intraductal US

BACKGROUND

Cholangiography and tissue sampling (brush cytology, biopsy) are the standard nonsurgical techniques for determining whether a bile duct stricture is benign or malignant. The aim of this study was to determine whether intraductal US is of assistance in distinguishing benign from malignant biliary strictures.

METHODS

A retrospective review was undertaken of 30 patients with indeterminate bile duct strictures who underwent ERCP and tissue sampling from September 1999 to November 2000. A 20 MHz over-the-guidewire intraductal US catheter probe was used during ERCP for further examination of the strictures. Final diagnoses of malignant strictures (18 patients) were confirmed histopathologically; confirmation of benign stricture (12 patients) was based on negative tissue sampling plus extended clinical follow-up.

RESULTS

Based on retrospective blinded review, the diagnosis by ERCP was correct in 67% of patients, by tissue sampling in 68%, by combined ERCP/tissue sampling in 67%, and by intraductal US in 90% (p = 0.04 vs. ERCP/tissue sampling) of cases. No complication of intraductal US or ERCP was recorded.

CONCLUSIONS

Intraductal US is safe and can improve on the ability at ERCP to distinguish benign from malignant biliary strictures.

The role of endoscopic ultrasound in hepatobiliary disease

The evaluation of hepatobiliary disease continues to change as new technologies are introduced. One of the more recent advances in hepatobiliary imaging has been the application of endoscopic ultrasound (EUS). Endoscopic retrograde cholangiopancreatography, computed tomography, conventional ultrasound, and magnetic resonance imaging were previously the primary means of evaluating hepatobiliary disease. The role of EUS as both a substitute and a complement for these historical imaging modalities continues to evolve. This review examines the current literature on EUS in the evaluation of hepatobiliary diseases, including choledocholithiasis, microlithiasis, biliary strictures, obstructive jaundice, cholangiocarcinoma, gallbladder polyps, and liver lesions.

Intraductal ultrasonography for hepatocellular carcinoma with tumor thrombi in the bile duct: comparison with polypoid cholangiocarcinoma

BACKGROUND AND AIM

Tumor thrombi in the bile duct caused by hepatocellular carcinoma (HCC), and cholangiocarcinoma show polypoid lesions on cholangiographic findings. This study prospectively compared the images of intraductal ultrasonography between HCC and polypoid cholangiocarcinoma.

METHODS

In five patients with tumor thrombi in the bile duct caused by HCC, a 2.0 mm diameter ultrasonic probe with a frequency of 20 MHz was inserted into the bile duct via the transpapillary route (n = 4) or the transhepatic route (n = 1). The images were compared to that of 65 patients with cholangiocarcinoma.

RESULTS

In all patients with HCC, intraductal ultrasonography showed a 'polypoid tumor with a narrow base'. In 16 of 65 patients with cholangiocarcinoma, it showed a 'polypoid tumor with a narrow base'. When intraductal ultrasonography showed a 'polypoid tumor with a narrow base', the findings of a positive 'nodule within a nodule' (40 vs 0%; P < 0.05), and the absence of a 'papillary-surface pattern' (80 vs 13%; P < 0.05) were more highly associated with tumor thrombi caused by HCC than to polypoid-type cholangiocarcinoma.

CONCLUSIONS

Intraductal ultrasonography was useful to distinguish between tumor thrombi caused by HCC and polypoid-type cholangiocarcinoma.

Intraductal ultrasound in the biliary tract

Although endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging, endosonography using dedicated echoendoscopes has some serious drawbacks, including the diameter of the echoendoscope (12 to 13 mm), the lack of intraluminal examination of the pancreatobiliary duct system due to the size of the instrument, unsatisfactory image quality and resolution for small lesions, and the need for a second examination separate from the previous routine endoscopy. Recently developed ultrasonographic miniprobes (diameter, about 2 mm; frequency, 12 to 20 MHz) can be passed through the working channel of standard endoscopes to provide high-frequency ultrasound images. These miniprobes may overcome some of the noted drawbacks and add to the safety and convenience of patients. Moreover, in various diseases of the gastrointestinal tract and the pancreatobiliary ductal system, the diagnostic accuracy of miniprobe ultrasonography has been proven to be superior to that of EUS. Miniprobe ultrasonography is a promising tool that adds new capabilities to the armamentarium of gastroenterologic diagnostic assessment.

Multiple bile duct biopsies using a sheath with a side port: usefulness of intraductal sonography

OBJECTIVE

We clarified the number of biopsies required to determine malignancy of the biliary tract on the basis of the type of bile duct tumor.

SUBJECTS AND METHODS

Patients with a biliary tract malignancy (n = 33) and a benign biliary stenosis (n = 3) underwent biopsy via the percutaneous transhepatic route. We performed intraductal sonography using a 20-MHz probe with a 2.0-mm diameter. The sonographic findings were prospectively classified as polypoid, circular, or semicircular. The tip of a long 9-French sheath with a side port was wedged into the stenosis, and six specimens were obtained with a 1.8-mm-diameter forceps with serrated cups.

RESULTS

When cholangiography or intraductal sonography showed a polypoid lesion, the sensitivity of two biopsies was 100% (6/6). When cholangiography showed a stenotic lesion, the sensitivity of nine biopsies (96%, 26/27) was superior to that of two biopsies (74%, 20/27; p < 0.05). When intraductal sonography showed a circular lesion, the sensitivity of three biopsies (100%, 14/14) was superior to that of a single biopsy (64%, 9/14; p < 0.05). When it showed a semicircular lesion, the sensitivity of nine biopsies (92%, 12/13) was superior to that of two biopsies (54%, 7/13; p < 0.05).

CONCLUSION

Bile duct biopsy using a sheath with a side port has a high sensitivity. However, the number of biopsies required depends on the cholangioscopic and intraductal sonographic appearance of the tumor.

Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma

BACKGROUND

The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated.

METHODS

In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens.

RESULTS

Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05).

CONCLUSIONS

Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy

BACKGROUND

An imaging modality that can be used to identity small stones after a biliary lithotripsy is required. Intraductal ultrasonography was evaluated by using percutaneous transhepatic cholangioscopy as the gold standard.

METHODS

Lithotripsy, under percutaneous transhepatic cholangioscopy guidance, was performed in 20 patients. A thin-caliber ultrasonic probe (2.0 mm in diameter and 20 MHz frequency) was inserted into the bile duct through the percutaneous tract after lithotripsy, and residual stones were identified. This was followed by percutaneous transhepatic cholangioscopy.

RESULTS

In the extrahepatic bile ducts, intraductal ultrasonography provided images of all the stones demonstrated on cholangioscopy (n = 11). The sensitivity was superior to that of cholangiography (P < 0.005). However, in the intrahepatic bile ducts, intraductal ultrasonography only visualized the stones located in the cannulated lobe. Extrahepatic stones smaller than 5.0 mm in diameter or in a common hepatic duct larger than 15.0 mm in diameter were missed by cholangiography, but were visualized by the use of intraductal ultrasonography (P < 0.05).

CONCLUSIONS

Intraductal ultrasonography is equivalent to cholangioscopy in the extrahepatic bile ducts. Cholangiography and intraductal ultrasonography should be used in combination to image intrahepatic and extrahepatic stones.

EUS-guided fine-needle aspiration cytodiagnosis of hilar cholangiocarcinoma: a case series

BACKGROUND

Improved methods of tissue diagnosis for obstruction at the hilum of the liver (porta hepatis) have contributed substantially to the preoperative diagnosis of cholangiocarcinoma. Endoscopic brushing during endoscopic retrograde cholangiopancreatography (ERCP), with sensitivity of 20% to 100%, is the preferred technique for obtaining accurate pathologic results. Extensive hepatic resection with curative intent as well as modern approaches to palliative treatment are based on definitive diagnosis. This is a study involving endosonography-guided, fine-needle aspiration (EUS-FNA) for cytodiagnosis of potentially operable hilar cholangiocarcinoma when brush cytology was negative or unavailable.

METHODS

Ten consecutive patients (7 men, 3 women; age 47 to 78 years, median 59 years) with bile duct strictures at the hepatic hilum, diagnosed by CT and/or ERCP, underwent EUS-FNA using linear echoendoscopes and 22-gauge needles.

RESULTS

Adequate material was obtained in nine patients. Cytology revealed cholangiocarcinoma in seven and hepatocellular carcinoma in one. One benign inflammatory lesion identified on cytology proved to be a false-negative finding by frozen section. Metastatic locoregional hilar lymph nodes were detected in two patients, and in one patient the celiac and para-aortic lymph nodes were aspirated to obtain tissue proof of distant metastasis. There were no complications.

CONCLUSIONS

When standard methods of tissue diagnosis are inconclusive, EUS-guided FNA may have a potential role in the diagnosis of primary cholangiocarcinoma of the hepatic hilum. As a new, minimally invasive approach, it proved to be technically feasible without significant risks.

Intraductal US in assessing the effects of radiation therapy and prediction of patency of metallic stents in extrahepatic bile duct carcinoma

BACKGROUND

We assessed the local effects of radiation therapy using intraductal ultrasonography (US) to predict the subsequent patency of metallic stents in bile duct carcinoma.

METHODS

Data from 16 patients with extrahepatic-suprapancreatic bile duct carcinoma were prospectively analyzed. Thin-caliber US probes (2.0 mm diameter/20 MHz frequency and 2.8 mm diameter/10 MHz frequency) were inserted into the bile duct via a percutaneous transhepatic approach pre- and postradiation therapy to evaluate the effects of treatment. When intraductal US showed a reduction in bile duct wall thickness of 30% or greater or showed a lessening of vessel (portal vein or right hepatic artery) invasion, radiation therapy was judged to be effective. Noncovered metallic stents were then inserted, and their patency was evaluated over time.

RESULTS

When radiation therapy was effective (n = 7), the metallic stent was patent for 522 +/- 571 days. When radiation was ineffective (n = 9), the metallic stent was patent for only 188 +/- 159 days. When radiation therapy was ineffective, stent obstruction occurred in 6 of 9 (66.7%) patients during this period, significantly more frequently than when radiation therapy was effective (14.3%, p < 0.05).

CONCLUSIONS

Assessment of local radiation effects by intraductal US is useful for predicting patency of metallic stents in bile duct cancer.

Gastrointestinal miniprobe sonography: the current status

Endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging. The usefulness and effectiveness of EUS have been established during the past few years. However, endosonography using dedicated echoendoscopes (7.5/12 MHz) has some serious drawbacks, as follows: 1) Combining endoscopy and ultrasonography in one instrument increases the diameter of such echoendoscopes (12-13 mm); 2) Because of the large diameter, complete passage of severe strictures is often not possible and, for examination of the pancreatobiliary duct system, is not feasible at all; 3) Image quality and resolution for small lesions is not always satisfactory; and 4) Conventional endosonography requires a second examination separate from the previous routine endoscopy. Recently developed ultrasonographic miniprobes (diameters about 2 mm; frequencies 12-20 MHz) can be passed through the working channel of standard endoscopes to provide high frequency ultrasound images. These miniprobes might overcome some of the above-mentioned drawbacks and contribute to patients' security and convenience. Moreover, in various diseases of the GI tract and the pancreatobiliary duct system, diagnostic accuracy of miniprobe ultrasonography has been shown to be even superior to that of EUS. In summary, miniprobe ultrasonography seems to be a promising tool in the armamentarium of gastroenterological diagnostics.

Prospective evaluation of an over-the-wire catheter US probe

BACKGROUND

Pancreaticobiliary strictures identified at endoscopic retrograde cholangiopancreatography (ERCP) can be evaluated by intraductal ultrasonography (US). Two major difficulties are that sphincterotomy may be required and the stricture may not be traversable. We prospectively evaluated the ease and success of intraductal US using a new over-the-wire catheter US probe.

METHODS

Biliary or pancreatic strictures discovered at ERCP were imaged with the new probe. Intraductal US performance times, image clarity, imaging depth and technical ease were measured.

RESULTS

Twenty-one patients with a variety of inflammatory and malignant pancreaticobiliary lesions were studied. Thirteen of the 16 (81%) masses imaged by intraductal US were 10 mm or less in diameter. Sphincterotomy was not required. All strictures traversed by a guidewire were imaged. The sphincter of Oddi was successfully imaged in all patients with intact normal sphincters. Performance of intraductal US was rated as technically easy in all cases and image clarity was rated as good or very good in 15 of 21 (71%) cases.

CONCLUSIONS

The new over-the-wire catheter US probe facilitates intraductal US. Sphincterotomy is avoided and strictures are successfully traversed. This probe makes it possible to image the sphincter of Oddi.

Intraductal ultrasonography (IDUS) of the pancreato-biliary duct system. Personal experience and review of literature

Endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging. Usefulness and effectiveness of EUS have been established during the past few years. However, endosonography using dedicated echoendoscopes (7.5/12 MHz) has some serious drawbacks: (1) combining endoscopy and ultrasonography in one instrument increases the diameter of such echoendoscopes (13 mm); (2) as a result of the large diameter insertion into the pancreato-biliary duct system is not feasible at all; (3) image quality and resolution for small lesions is not always satisfactory; and (4) conventional endosonography needs a second examination separate from the previous routine endoscopy. Recently developed ultrasonographic miniprobes (diameters about 2 mm; frequencies 12-20 MHz) can be passed through the working channel of standard endoscopes to provide high-frequency ultrasound images. These miniprobes might overcome some of the above mentioned drawbacks and contribute to patients' security and convenience. Moreover, in various diseases of the pancreato-biliary duct system diagnostic accuracy of miniprobe ultrasonography has been shown to be superior to that of EUS. In summary, miniprobe ultrasonography appears to be a promising addition to the armamentarium of gastroenterologic diagnostics.

Preoperative assessment of extrahepatic bile duct carcinoma using three-dimensional intraductal US

BACKGROUND

We investigated the utility of a new imaging modality, three-dimensional intraductal ultrasonography (US), for staging bile duct cancer.

METHODS

In eight patients with extrahepatic bile duct carcinoma, two- and three-dimensional intraductal US was used to assess tumor invasion of the right hepatic artery, portal vein, and pancreatic parenchyma before resection. The findings were correlated with histologic information from the resected specimen.

RESULTS

Three-dimensional intraductal US enabled accurate assessment of tumor invasion of the right hepatic artery in 88% of cases, the portal vein in 100%, and pancreatic parenchyma in 100%. Two-dimensional intraductal US enabled accurate assessment of invasion of these structures in 88%, 88%, and 88% of cases.

CONCLUSIONS

Three-dimensional intraductal US is useful in assessing tumor stage in bile duct carcinoma.

Preoperative assessment of congenital bile duct dilatation using intraductal US

BACKGROUND

Although congenital bile duct dilatation is frequently associated with biliary tract cancer, conventional cholangiography often does not demonstrate small ductal tumors. This is the first prospective study of the value of intraductal ultrasonography (US) in the examination of the extrahepatic bile ducts in patients with congenital bile duct dilatation.

METHODS

Intraductal US via a transpapillary route was used in consecutive patients with congenital bile duct dilatation. A 2.0 mm diameter, 20 MHz frequency catheter probe was used. The images were correlated with the results of histologic examination of the resection specimens.

RESULTS

Intraductal US was performed successfully via the transpapillary route in 8 of 10 patients. In the other 2 patients, the percutaneous transhepatic route was used. In the 6 patients with cylindrical dilatation, intraductal US demonstrated the entire extrahepatic bile duct. In 1 patient, it showed a bile duct cancer not demonstrated by cholangiography. In 2 of the 4 patients with cystic dilatation, intraductal US did not demonstrate the entire extrahepatic bile duct because of the low penetration depth of the probe. Percutaneous transhepatic cholangioscopy was required in these patients.

CONCLUSIONS

Intraductal US is useful for demonstrating cancers in the extrahepatic bile ducts in patients with congenital cylindrical ductal dilatation.

Bile duct wall thickness measured by intraductal US in patients who have not undergone previous biliary drainage

BACKGROUND

We investigated the bile duct wall thickness measured on intraductal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile duct, bile duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on wall thickness.

METHODS

The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. Intraductal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile duct wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images.

RESULTS

Bile duct wall thicknesses of the common hepatic duct for the control group (n = 95), cancer at the distal bile duct group (n = 9), bile duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 +/- 0.3 mm (mean +/- SD), 0.8 +/- 0.5 mm, 0.8 +/- 0.6 mm, and 0.8 +/- 0. 5 mm, respectively. No significant differences (p > 0.05) were found between them. However, wall thickness for the cancer extension to the common hepatic duct group (n = 4, 2.0 +/- 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 +/- 0.4 mm) were significantly greater than in the other groups (p < 0.005).

CONCLUSIONS

In patients who have not undergone previous biliary drainage, the bile duct wall thickness was not thicker in patients with obstructive jaundice. However, the duct wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups.

Clinical implications of endoluminal ultrasonography using through-the-scope catheter probes

BACKGROUND

Ultrasound catheter probe-assisted endosonography is a relatively new technique. The aim of this prospective multicenter study was to determine its potential clinical impact by assessing changes in diagnostic and therapeutic management affected by catheter probes compared with ultrasound endoscopes.

METHODS

Endosonographers at three centers selected theoretic diagnostic and therapeutic plans that would be followed if neither catheter probes nor ultrasound endoscopes were available. Patients with suitable lesions underwent endosonography with catheter probes followed by an ultrasound endoscope. Diagnostic and therapeutic plans were noted after each examination.

RESULTS

Sixty-six patients, of whom 15 had a stenotic esophageal cancer, 39 had a mucosal or submucosal lesion, and 12 had a stricture of the pancreaticobiliary system or the gastrointestinal tract, were enrolled. If neither form of endosonography were available, invasive or surgical diagnostic procedures would have been performed on 23 (35%) patients and surgical therapy would have been planned in 31 (47%) patients. Catheter probe-assisted ultrasonography and endoscopic ultrasonography led to a less invasive diagnostic plan in 11 (16%) and 12 (18%) patients and a less invasive therapeutic plan in 10 (15%) and 14 (21%) patients, respectively (p > 0.1 for differences).

CONCLUSIONS

Catheter probe-assisted endosonography has a modest effect on diagnostic and therapeutic management, comparable with endoscopic ultrasonography in the same patients. The vast majority of effected changes are toward less invasive management.

Characterization of biliary strictures using intraductal ultrasonography: comparison with percutaneous cholangioscopic biopsy

BACKGROUND

We determined the accuracy of intraductal ultrasonography (IDUS) in distinguishing between bile duct cancer and benign bile duct disease.

METHODS

Patients (n=42) who required bile duct biopsy using percutaneous transhepatic cholangioscopy (PTCS) to evaluate bile duct strictures or filling defects were studied. A thin-caliber ultrasonic probe (2.0 mm diameter and 20 MHz frequency) was inserted into the bile duct, and its images were prospectively reviewed before PTCS.

RESULTS

Disruption of the bile duct wall structure, seen on IDUS, was associated with malignancy in 25 of 26 patients. When IDUS demonstrated a lesion with normal bile duct structure, six of nine patients were found to have no malignancy. IDUS demonstrated no intraductal lesion in seven patients, and bile duct biopsy also did not indicate cancer in any of these patients. The accuracy, sensitivity, and specificity of IDUS for diagnosing bile duct cancer were 76%, 89%, and 50%, respectively. When used in tandem with IDUS, the sensitivity of bile cytology (64%) and PTCS (93%) improved to 96% and 100%, respectively.

CONCLUSIONS

The accuracy of IDUS for diagnosing bile duct cancer was less than that of PTCS (95%). However, the sensitivity for bile cytology, or bile duct biopsy improved when performed in combination with IDUS.

Intraportal endovascular ultrasonography for assessment of vascular invasion by biliary tract cancer

BACKGROUND

This study was performed to investigate the diagnostic accuracy of intraportal endovascular ultrasonography (IPEUS) in assessing vascular invasion by biliary tract cancer.

METHODS

A prospective study of 31 consecutive patients with biliary tract cancer was performed. All patients underwent surgery. The sonographic criterion for right hepatic artery invasion was interruption of the hyperechoic layer or encasement by tumor. The sonographic criterion for portal vein invasion was obliteration of the echogenic band of the portal vein. IPEUS findings were confirmed by surgical exploration and pathologic examination of resected specimens.

RESULTS

Right hepatic artery invasion was confirmed in resected specimens in seven patients and by operative findings in four patients. Portal vein invasion was confirmed in resected specimens in six patients and by operative findings in five patients. For diagnosis of right hepatic artery invasion, the sensitivity, specificity, and overall accuracy of IPEUS were all 100%; respective values were 63.6%, 84.2%, and 76.7% for angiography. For diagnosis of portal vein invasion, the sensitivity, specificity, and overall accuracy of IPEUS were 100%, 95%, and 96.8%, respectively. The corresponding values were 63.6%, 89.5%, and 80% for portography and 54.5%, 85%, and 74.2%, respectively, for CT.

CONCLUSION

IPEUS will improve the assessment of vascular invasion at the hepatic hilum by biliary tract cancer.

Influence of biliary drainage catheter on bile duct wall thickness as measured by intraductal ultrasonography

OBJECTIVE

To determine the influence of biliary drainage catheter placement on bile duct wall thickness, we performed intraductal ultrasonography (IDUS) in patients before and after biliary drainage.

METHODS

Patients underwent IDUS before and after either short-term (n = 9, 6 to 8 days) or long-term (n = 9, 14 to 35 days) biliary drainage using a thin (2.0 mm diameter), 20 MHz probe inserted by means of a transpapillary route or a percutaneous tract. The bile duct wall thickness (mean +/- standard deviation) was retrospectively measured at the upper portion of the common hepatic duct.

RESULTS

The bile duct wall thickness increased from 0.8+/-0.4 mm (predrainage) to 2.0+/-1.6 mm (post-drainage) in the long-term group (p < 0.001) but was not significantly increased in the short-term group.

CONCLUSIONS

The bile duct wall thickness as measured on IDUS appears to be increased after placement of biliary drainage catheters.

[Palliative therapy of carcinomas of the biliary system]

CARCINOMA OF THE GALLBLADDER: Only patients suffering from advanced disease have symptoms, that is pain, jaundice, weight loss. Mean 5-year survival rate tends to be lower than 5%. Tumors can be resected with negative margins in 15 to 25% of the patients. Obstructive jaundice can be managed with endoscopic biliary stent in 84% of the patients. After radiotherapy tumor regression is observed in 80% of the patients. Their mean survival time is 10 months.

CHOLANGIOCARCINOMAS

More than 90% of the patients present with jaundice. At the time of presentation, 50% of the patients already have metastases to lymph nodes. Mean total survival time of all patients is 12 months. Surgical resection can successfully be performed in 30 to 40% of the patients suffering from proximal cholangiocarcinomas. Distal unresectable tumors are best palliated with an endoscopically placed stent in 97.5% of the patients. Patients having undergone radiotherapy will have a mean survival time of 9 to 12 months. There is a 12% response rate after chemotherapy with single agents and one of 23% after combined regimens. Intraarterial application of chemotherapy results in 44% response rate.

CONCLUSION

Carcinomas of the biliary tract are often diagnosed at advanced inoperable stages. Patients quality of life can be ameliorated by palliative treatment, i.e. biliary stents, radio-, chemotherapy. Mean survival time does normally not exceed 1 year.

Assessment of right hepatic artery involvement in patients with biliary tract cancer using color Doppler ultrasonography

The accuracy of color Doppler ultrasonography (CDUS) in diagnosing right hepatic artery (RHA) involvement was preoperatively evaluated in 28 patients with biliary tract cancer. When a tumor partially or completely surrounded the RHA, the circumferential involvement was diagnosed as positive. With B-mode ultrasonography imaging alone in the 10 nonsurgical patients, the correspondence rates with angiography for the presence of invasion, absence of invasion, and overall were 33%, 0%, and 10%, respectively. However, CDUS allowed clearer visualization of the RHA than did B-mode imaging, and the correspondence rates of CDUS with angiography were 100%, 43%, and 60%, respectively. In the 13 surgical patients, the accuracy levels of B-mode imaging, CDUS, computed tomography, and angiography for the detection of RHA involvement were 46%, 77%, 58%, and 92%, respectively, when compared with surgical and histopathologic findings. Although the accuracy of CDUS was lower than that of angiography, it can be performed repeatedly and noninvasively. CDUS is expected to be useful for the initial assessment of RHA involvement.

Endoscopic and percutaneous intervention in malignant obstructive jaundice

Most patients with malignant obstructive jaundice have inoperable disease at presentation. There is debate regarding the best approach to palliate these patients, i.e., surgical versus endoscopic versus percutaneous drainage. The purpose of this article is to review the current literature in an unbiased fashion, and to present a rationale for management. A multi-disciplinary approach is needed if we are to provide the best care for patients with standardization of definitions, complications, and outcomes between specialities such that meaningful comparisons can be made between studies. The need for prospective randomized trials is clear from the currently deficient literature.