Diagnostic accuracy of ultrasound, computed tomography, and endoscopic retrograde cholangiopancreatography in the detection of obstructive jaundice

[Acute cholangitis]

Acute cholangitis is a potentially severe infection of the biliary tract, resulting from a biliary obstruction. The most frequent cause of cholangitis is common duct stones. Biliary tract obstruction and secondary bacterial colonization lead to infection. In most cases, the causative agents are intestinal microflora, mostly aerobic microorganisms (and, to a lesser extent, anaerobic bacteria). The Charcot triad constitutes the most frequent symptomatology. Diagnosis is confirmed by means of radiological techniques, such as ultrasonography, computed tomography scan, or magnetic resonance imaging of the liver, in which signs of obstruction of the biliary tract can be detected and its etiology can often be determined. In most patients the treatment of choice is early appropriate antimicrobial therapy and biliary drainage, generally using endoscopic techniques.

Intrahepatic cholestasis as a paraneoplastic syndrome associated with pheochromocytoma

Pheochromocytoma is a rare tumor of chromaffin cells that secrete catecholamines and several cytokines. The clinical manifestations are protean and may include hypertension, weight loss, sweating, palpitation, headache, anxiety, tremor, nausea, vomiting, and hypercalcemia. The tumor can mimic many unrelated diseases, leading to significant delay and difficulty in diagnosis. We report a case of a 37-yr-old male admitted with jaundice, dark urine, fever, and signs of a systemic inflammatory response. Abdominal computed tomography revealed a heterogeneously enhancing tumor between the pancreatic tail and left kidney. There was no evidence of obstruction to bile flow, neoplastic involvement of the liver or bile ducts, or infectious etiology. The tumor was removed and found to be a pheochromocytoma. Immunohistochemical analysis revealed the presence of interleukin-1beta in the tumor cells. After surgery, the jaundice resolved without further treatment, leading us to the conclusion that it was a paraneoplastic phenomenon possibly related to interleukin-1beta production. We suggest that occult pheochromocytoma should be added to the differential diagnosis of unexplained intrahepatic cholestasis.

Diagnosis and management of cholecystitis and cholangitis

Cholelithiasis is a prevalent condition in Western populations. Most cases are asymptomatic but complications can occur. Acute cholangitis, cholecystitis, and gallstone pancreatitis are the most common biliary tract emergencies and are usually caused by biliary calculi. Whenever possible, acute cholecystitis should be treated with early LC. AAC is an uncommon condition usually affecting patients with significant comorbidities. Treatment is usually with percutaneous cholecystostomy, which often is also the only required therapy. Endoscopic drainage is the preferred form of biliary decompression in acute cholangitis and these patients should subsequently undergo elective LC unless unfit for surgery. Effective and optimal management of biliary tract emergencies relies on close cooperation between gastroenterologist, surgeon, and radiologist.

A prospective comparison of the diagnostic accuracy of ERCP, MRCP, CT, and EUS in biliary strictures

BACKGROUND

The differential diagnosis of biliary strictures remains a challenge. This study evaluated magnetic resonance cholangiopancreatography (MRCP) as a new procedure in comparison with the established methods of diagnosis including ERCP or percutaneous transhepatic cholangiography (PTC), CT, and EUS.

METHODS

Fifty patients (21 men, 29 women, mean age 65.7 years) with jaundice but no pain suspected to have biliary strictures were enrolled in this prospective study. MRCP, ERCP/PTC, CT, and EUS were performed prospectively; images and videotapes (EUS) of these tests were reviewed blindly under standardized conditions. Reference standards for comparison were surgery, a biopsy confirming malignancy, or the clinical course during follow-up (at least 12 months) in cases without histopathologic proof of malignancy.

RESULTS

Seven patients ultimately proved to have jaundice caused by parenchymal liver disease and 43 had a biliary stricture (17 benign, 26 malignant). Forty patients underwent all 4 imaging tests. There were 10 patients in whom patient-specific problems precluded some procedures but who were included in an intention-to-diagnose analysis. The sensitivity and specificity for diagnosis of malignancy in the 50 patients were as follows: 85% / 75% for ERCP/PTC, 85% / 71% for MRCP, 77% / 63% for CT, and 79% / 62% for EUS, with similar values in the 40 patients who underwent all 4 imaging methods. The combination of MRCP and EUS improved specificity.

CONCLUSIONS

Although MRCP provides the same imaging information as direct cholangiography, it has limited specificity for the diagnosis of malignant strictures. In the differential diagnosis of biliary strictures, several tests including ERCP-guided tissue diagnosis are still required, and MRCP has only a limited clinical role.

MR and ultrasound in screening of patients with suspected biliary tract disease

PURPOSE

The diagnostic value and cost-efficiency of MR imaging were compared with US before endoscopic retrograde cholangiopancreatography (ERCP) in patients with clinically suspected biliary tract disease.

MATERIAL AND METHODS

In a prospective study of 219 patients, 85 were examined with both MR and US before ERCP.

RESULTS

To find the correct diagnosis in the jaundiced patients the sensitivity of US, MR and ERCP was 53%, 93%, and 89%, respectively. In the patients with abdominal upper quadrant pain and normal serum bilirubin, the sensitivity of US, MR and ERCP was 50%, 100% and 70%, respectively. Examination with MR costs four times more than US. Screening with US and supplemental MR in non-diagnostic cases would cost 80% of the total amount compared to screening with MR only.

CONCLUSION

MR had a higher sensitivity than US for diagnosing biliary tract disease and MR was superior to US in visualising stones in the common bile duct and in diagnosing the cause of cholestasis. However, screening with US and supplemental MR in non-diagnostic cases is at present most cost-effective. With increased accessibility and slightly lower costs, MR will probably replace US as screening method in patients with suspected biliary tract disease.

Acute (ascending) cholangitis

Cholangitis is an infection of an obstructed biliary system, most commonly due to common bile duct stones. Bacteria reach the biliary system either by ascent from the intestine or by the portal venous system. Once the biliary system is colonized, biliary stasis allows bacterial multiplication, and increased biliary pressures enable the bacteria to penetrate cellular barriers and enter the bloodstream. Patients with cholangitis are febrile, often have abdominal pain, and are jaundiced. A minority of patients present in shock with hypotension and altered mentation. There is usually a leukocytosis, and the alkaline phosphatase and bilirubin levels are generally elevated. Noninvasive diagnostic techniques include sonography, which is the recommended initial imaging modality. Standard CT, helical CT cholangiography, and magnetic resonance cholangiography often add important information regarding the type and level of obstruction. Endoscopic sonography is a more invasive means of obtaining high-quality imaging, and endoscopic or percutaneous cholangiography offers the opportunity to perform a therapeutic procedure at the time of diagnostic imaging. Endoscopic modalities currently are favored over percutaneous procedures because of a lower risk of complication. Treatment includes fluid resuscitation and antimicrobial agents that cover enteric flora. Biliary decompression is required when patients do not rapidly respond to conservative therapy. Definitive therapy can be performed by a surgical, percutaneous, or endoscopic route; the last is favored because it is the least invasive and has the lowest complication rate. Overall prognosis depends on the severity of the illness at the time of presentation and the cause of the biliary obstruction.

Computer-assisted diagnosis in gastroenterology

During the last 20 years, Danish gastroenterologists and biostatisticians have been involved in practical and theoretical research aimed at providing computer-assisted decision support in clinical practice. On the practical side, we summarize two clinical applications, one in the acute abdomen, the other in jaundice. The former project is part of a worldwide effort which appears able to reduce considerably the perforated appendix rate and the negative laparotomy rate. In the latter project, also entwined in international activities, three methods of early statistical discrimination of jaundice causes have been tested, and it has been shown how ultrasonographic data can be incorporated into the diagnostic assessment. On the theoretical side, a Dutch-Danish group has been looking into how one best designs a trial and analyses its data in the context of measuring the quality and impact of machine-made diagnostic advice. Having pointed out the international ramifications of these activities, we outline what may lie ahead: Gastroenterologists must be prepared to join large-scale field trials of clinical advice-giving software. In the future, however, such software will often become embedded in general hospital recordkeeping systems.

Tumour-associated trypsin inhibitor in the diagnosis of pancreatic carcinoma

The serum values of tumour-associated trypsin inhibitor (TATI) were measured in a prospective series of 97 patients with jaundice, 36 patients with unjaundiced cholestasis and 21 patients with suspicion of chronic pancreatitis or a pancreatic tumour, to assess its value in diagnosing pancreatic cancer. There were altogether 15 patients with cancer of the pancreas and 2 patients with cancer of the papilla of Vater. The highest serum TATI values were noticed in patients with choledocholithiasis, and raised values were also seen in patients with malignant disease of the liver or bile ducts. In the patients with pancreatic cancer, chronic pancreatitis or benign liver disease, the serum TATI values showed lower levels. The sensitivity of TATI in diagnosing pancreatic cancer was 41.1% with a specificity of 63.5% and an efficiency of 61.0%. In comparison to carcinoembryonic antigen (CEA), carbohydrate antigens CA 50, CA 242, tissue polypeptide antigen and tissue polypeptide-specific antigen, TATI showed a lower diagnostic value. When TATI was analysed in combination with the other markers (two tests positive), the combination of CEA with TATI reached the highest specificity (95.6%), efficiency (89.6%) and positive likelihood ratio (9.3). The results suggest that the diagnostic value of TATI is inferior to that of the established markers, but because of its different nature, it may be of help when used in combination as a complementary serum tumour marker in the diagnosis of pancreatic cancer.

A prospective study of serum tumour markers carcinoembryonic antigen, carbohydrate antigens 50 and 242, tissue polypeptide antigen and tissue polypeptide specific antigen in the diagnosis of pancreatic cancer with special reference to multivariate diagnostic score

The aim of this study was to assess by a stepwise multivariate discriminant analysis the value of four current serum tumour markers - carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 50 and CA 242 and tissue polypeptide antigen (TPA) - and a new serum tumour marker, tissue polypeptide specific antigen (TPS), in the diagnosis of pancreatic cancer. The serum values were measured in a prospective series of patients with jaundice, with unjaundiced cholestasis and with a suspicion of chronic pancreatitis or a pancreatic tumour (n = 193). There were 24 patients with a cancer of the pancreas and two patients with a cancer of the papilla of Vater in this series. Our results showed that CA 50 (P < 0.001) and TPA (P < 0.01) were the best marker tests in predicting pancreatic malignancy. Also, the TPS (P = 0.07) and CA 242 (P = 0.08) tests showed marginally significant independent discriminating power, while the CEA test did not (P = 0.12). In order to sum up the contributions of different markers, a diagnostic score (DSI) was developed. The discrimination function was: DS1 = CA 50 x 1.75 + TPA x 0.62 + TPS x (-0.37) + CA 242 x (-1.21). The sensitivity of DS1 in detecting pancreatic cancer was 36% with a specificity of 90% and an efficiency of 82%. When the combination of CA 50 and TPA was used as a test, the discrimination function (DS2) was: DS2 = CA 50 x 0.69 + TPA x 0.67. The sensitivity of DS2 was 44% with a 88% specificity and an efficiency of 82%. According to this analysis, the further advantage gained by a computer-aided scoring system seems to be limited, since despite the considerably high specificity and efficiency its sensitivity remained low. In the present analysis the best combination in diagnosing pancreatic cancer was the combination of CA 50 and TPA.

Evaluation of a computer-based diagnostic score system in the diagnosis of jaundice and cholestasis

A prospective series of 220 patients with jaundice and/or cholestasis was analysed by means of discriminant analysis to evaluate the diagnostic value of various symptoms and signs and basic hepatopancreatobiliary laboratory tests in the differential diagnosis of these patients. In addition, a computer-based diagnostic score (DS) system was developed and compared with the diagnostic value of clinical evaluation (CE), ultrasound (US), computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP). A multivariate stepwise discriminant analysis showed five independent diagnostic factors in distinguishing extrahepatic and intrahepatic diseases: duration of jaundice (p = 0.002), serum protein concentrations (p = 0.002), Normotest (p = 0.04), fever during the past 3 months (p = 0.54), and age (p = 0.58). To sum up the contributions of independent factors, a DS was developed. The discrimination function was as follows: duration of jaundice x 0.97 + age x -0.40 + fever during the past 3 months x 0.33 + serum protein concentration x 0.35 + Normotest x -0.27. The diagnostic sensitivity of DS in the detection of extrahepatic disease was 96%, with a specificity of 80% and an efficiency of 93%. The sensitivities of the imaging methods (62-85%) were inferior to that of DS, whereas the specificities were better (94-98%). The sensitivity of CE was only slightly lower (86%) than that of DS, but the specificity was lowest (57%). In conclusion, relatively few (5 of 40) of the classical symptoms, signs, and biochemical tests proved to be independent diagnostic factors in distinguishing extrahepatic and intrahepatic diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Value of serum alkaline phosphatase, aminotransferases, gamma-glutamyl transferase, leucine aminopeptidase, and bilirubin in the distinction between benign and malignant diseases causing jaundice and cholestasis: results from a prospective study

A prospective study of 187 patients with jaundice and 33 patients with unjaundiced cholestasis was carried out to evaluate the value of serum bilirubin, alkaline phosphatase (ALP), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), gammaglutamyl transferase (GGT), and leucine aminopeptidase (LAP) in the differential diagnosis between benign and malignant diseases causing jaundice and/or cholestasis. In the patients with malignant disease (n = 60), the mean serum bilirubin and ALP concentrations were significantly higher (p < 0.001) than in the patients with benign disease (n = 160). Serum LAP, ASAT, ALAT, or GGT levels did not show any significant differences. A stepwise discriminant analysis was carried out to evaluate the value of laboratory tests in predicting malignancy. The discrimination function is DF = bilirubin x 0.71 + ALP x 0.58 + ASAT x -0.24 + ALAT x 0.18 + LAP x 0.08 + GGT x -0.22. When the discriminant function was considered as a diagnostic score (DS), the sensitivity of it in detecting malignancy was 58% with a specificity of 89% and an efficiency of 81%. The DS of serum bilirubin and ALP reached the sensitivity of 61% with a 87% specificity and an efficiency of 79%. The post-test probability of malignant disease calculated by in this test combination was 69%. The LR+ was 4.8 and LR- 0.44. In conclusion, serum bilirubin and alkaline phosphatase seem to be the most potential tests of these laboratory tests in distinguishing benign and malignant causes of jaundice and/or cholestasis, high levels being suggestive of malignant disease.(ABSTRACT TRUNCATED AT 250 WORDS)