The role of grey scale ultrasonography in the investigation of jaundice

Advances in the investigation of obstructive jaundice

The causes of obstructive jaundice are varied, and timely, accurate methods of investigation are essential to avoid the development of complications. Imaging, invasive or non-invasive, should be carefully selected depending on the suspected underlying pathology in order to determine the degree and level of obstruction along with tissue acquisition and staging where relevant. Several imaging techniques will also allow subsequent therapeutic interventions to be carried out. This article reviews advances in the investigation of obstructive jaundice, highlighting recent developments, many of which at present remain restricted to large centres of expertise, but are likely to become more widespread in use as research progresses and local experience continues to improve.

Nonoperative imaging techniques in suspected biliary tract obstruction

Evaluation of suspected biliary tract obstruction is a common clinical problem. Clinical data such as history, physical examination, and laboratory tests can accurately identify up to 90% of patients whose jaundice is caused by extrahepatic obstruction. However, complete assessment of extrahepatic obstruction often requires the use of various imaging modalities to confirm the presence, level, and cause of obstruction, and to aid in treatment plan. In the present summary, the literature on competing technologies including endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiopancreatography (PTC), endoscopic ultrasound (EUS), intraductal ultrasonography (IDUS), magnetic resonance cholangiopancreatography (MRCP), helical CT (hCT) and helical CT cholangiography (hCTC) with regards to diagnostic performance characteristics, technical success, safety, and cost-effectiveness is reviewed. Patients with obstructive jaundice secondary to choledocholithiasis or pancreaticobiliary malignancies are the primary focus of this review. Algorithms for the management of suspected obstructive jaundice are put forward based on current evidence. Published data suggest an increasing role for EUS and other noninvasive imaging techniques such as MRCP, and hCT following an initial transabdominal ultrasound in the assessment of patients with suspected biliary obstruction to select candidates for surgery or therapeutic ERCP. The management of patients with a suspected pancreaticobiliary condition ultimately is dependent on local expertise, availability, cost, and the multidisciplinary collaboration between radiologists, surgeons, and gastroenterologists.

Bile duct emptying in response to fat: a validation study

Fatty meal sonography has been suggested to assess patients with biliary pain after cholecystectomy, but the effects of gallbladder removal on biliary dynamics has not been studied prospectively. Before elective cholecystectomy, 25 patients had their common hepatic ducts' diameter measured by ultrasonography before and after a fat stimulus. In 23, tests were repeated 1 month, 1 year, and 5 years after surgery. In preoperative studies, 5 patients showed dilatation after fat and 2 of these had stones in the common bile duct. However, another 4 patients with stones or sludge in the duct did not show dilatation, so that the response to fat was a poor indicator of patients requiring common bile duct exploration. No patient had major symptoms after surgery. At 1 month and 12 months, the response to fat was variable with more than half of those tested showing no decrease in duct size. A more consistent pattern emerged at 5 years, when 14 of 18 patients tested showed a decrease in common hepatic duct after fat; 3 were unchanged and 1 increased by 1 mm. The response to fat was less consistent and more difficult to measure in the common bile duct, even 5 years after operation. It was concluded that not all patients with indications for exploration of the common bile duct on operative cholangiography show a dilatation response to fat on preoperative testing. Also, fatty meal sonography should be used with caution because the response to fat in asymptomatic patients soon after operation is unpredictable, with occasional patients showing dilation without apparent obstruction. Measurement of common hepatic duct is preferred to common bile duct and increases in diameter of 1 mm are probably not significant.

Should surgeons operate on the evidence of ultrasound alone in jaundiced patients?

The biliary ultrasound scans of 132 patients having a laparotomy for jaundice have been reviewed to assess the role of ultrasound in the selection of patients for surgery. When scans were technically satisfactory the finding of a dilated extrahepatic duct (EHD) indicated obstructive jaundice in all cases, but the obstructing lesion in 5 per cent of such cases was too proximal for jaundice to be relieved by direct surgical decompression. Scans were further classified on the basis of abnormalities detected in the gallbladder. When EHD dilation was associated with gall bladder findings 'typical' of distal common bile duct (CBD) obstruction due to gall stones (small gallbladder with multiple gallstones) or tumour (dilated gallbladder without gallstones), surgically remediable obstruction was always present. Although ultrasound identified the obstructing lesion itself in a minority of cases, the cause of obstruction could be correctly inferred in 95 per cent of 'typical' scans. These results suggest that it is safe to proceed directly to surgery only when an experienced ultrasonographer demonstrates findings 'typical' of distal CBD obstruction due to gallstones or tumour.

The role of percutaneous transhepatic cholangiography and grey-scale ultrasound in the investigation and treatment of bile duct obstruction

A total of 123 patients undergoing fine needle percutaneous transhepatic cholangiography (PTC) in Newport between 1977 and 1981 are reviewed. PTC was well tolerated with a 9 per cent complication rate, a 5 per cent failure rate and no mortality. Of 111 patients in whom a diagnosis of biliary obstruction was subsequently confirmed, PTC showed the presence of obstruction in 94 per cent, its site in 92 per cent and the correct cause in 87 per cent. Eighteen jaundiced patients were spared laparotomy on the basis of the PTC findings. Grey-scale ultrasound scanning was performed in 99 of these patients. Of 93 with subsequently verified biliary obstruction, ultrasound confirmed the presence of obstruction in 66 per cent, its site in 33 per cent and its cause in 29 per cent. It is concluded that PTC is the more useful investigation in the management of biliary obstruction and that its use may avoid unnecessary surgery.

Current concepts in diagnosis. Approach to the patient with cholestatic jaundice

On the basis of clinical evaluation, the physician should decide whether extrahepatic biliary obstruction is highly unlikely, possible, or very likely. If it is highly unlikely, no further workup for obstruction is indicated unless the clinical picture is altered on follow-up examination. Further evaluation of the biliary tree is warranted in other patients. Ultrasonography is currently the noninvasive imaging technique of first choice. Computed tomography is indicated if ultrasonography has yielded technically inadequate results or in special circumstances when it is anticipated that decisions regarding further diagnostic evaluation or treatment will be importantly influenced by the results. Negative findings obtained in a technically adequate examination may represent a logical stopping point in the workup of patients in whom obstruction is considered merely a possibility to be excluded, but they should not dissuade the clinician from further diagnostic evaluation if obstruction is considered very likely. Indeed, in selected circumstances, such as cases in which choledocholithiasis is suspected after cholecystectomy, direct cholangiography is appropriate as an initial test. If evidence of obstruction is obtained by noninvasive imaging, direct cholangiography will be required in many patients before treatment, and the choice between percutaneous or retrograde cholangiography should be made on an individual basis. The challenge to the clinician is to minimize the risk, expense, and time involved in obtaining sufficient information for a definitive diagnosis and treatment.

Isolated elevation of serum alkaline phosphatase and biliary disease in the elderly

Disease presentation is commonly non-specific in the geriatric age group. An isolated elevation of serum alkaline phosphatase concentration may be the only pointer to underlying biliary disease.

Oriental cholangiohepatitis: preoperative radiographic and ultrasonographic diagnosis

The recent influx of immigrants from Southeast Asia into the United States has increased the likelihood of encountering unusual diseases heretofore rarely seen in this country. Among these disorders is Oriental cholangiohepatitis, a potentially life-threatening process whose early diagnosis is facilitated by roentgenographic findings. Ultrasonography can also provide useful information, although potential pitfalls in diagnosis should be recognized.

The reliability and clinical limitations of sonographic scanning of the biliary ducts

Sonographic scanning of the biliary ducts has been successfully used as a screening test to distinguish between patients with surgical and medical jaundice, with an accuracy of 90%. However, there is no consensus in the literature on what numerically defines a dilated biliary duct. To clarify this problem a prospective study of 102 consecutive patients was initiated to determine the sonographic size range of bile ducts in patients with and without extrahepatic ductal obstruction. The ultrasonic measurements were compared with direct measurements of the common bile duct, at surgery. The extrahepatic ductal system was visualized sonographically in 62% of the patients, while the intrahepatic ducts were found in 81% of the population. Direct measurements at operation agreed with the ultrasonic measurements in 84% of the patients. Analysis of the size range of the biliary ducts in patients with and without extrahepatic obstruction, by chi square analysis and the Student's t-test, allowed the following guidelines to be established. Extrahepatic bile duct obstruction was present if the extrahepatic bile ducts was 1 cm or wider (p less than 0.001) or if the intrahepatic bile duct was in excess of 0.5 cm (p less than 0.001). Similarly if the extrahepatic bile duct measured less than 0.8 cm sonographically, and the intrahepatic bile duct was 0.4 cm or less than bile duct, obstruction was not present (p less than 0.001).

Dynamic sonography in the evaluation of jaundice

The value of dynamic sonography as a screening procedure in 84 jaundiced patients was examined and compared with the clinical evaluation of a blind prospective study. The predictive value of the sonographic diagnosis of obstruction was 97% and 84% in nonobstruction. The corresponding values of the clinical distinction were 87% and 92% respectively. The level of obstruction was demonstrated in 95% and the cause of obstruction was diagnosed in 68%. When the cause of jaundice is uncertain or obstruction is suspected clinically, dynamic sonography can offer high diagnostic accuracy and guidance for invasive investigations.