Aetiological spectrum of obstructive jaundice and diagnostic ability of ultrasonography: a clinician's perspective

Abstract

Background: A vast array of invasive and non invasive diagnostic tests are available to diagnose and establish the etiology of surgical obstructive jaundice (SOJ). Invasive tests may cause cholangitis and imaging techniques like computed tomography(CT) scan and MRI are expensive. The aim of the present study was to test ultrasonography as the primary investigation in patients with SOJ and to elucidate the aetiological spectrum of obstructive jaundice as seen at a tertiary referral center.

Methods: 429 patients diagnosed as having obstructive jaundice on the basis of either CT, endoscopic retrograde cholangiopancreatography(ERCP), fine needle aspiration cytology(FNAC) or surgery underwent real time sonography over a 10 year period from May 1988 to Dec 1997. The diagnostic accuracy of ultrasonography for SOJ was established.

Results: Sonography correctly established the presence of obstructive jaundice in 380 of 429 patients. Of 429 patients (mean age 62.5 +/- 34.2 yrs, 229 males and 194 females) the sensitivity of ultrasound to correctly diagnose and establish the site of etiology of obstruction was 94% with a specificity of 96%. Malignant SOJ was much more common than benign causes (75.3% Vs. 24.7%). Carcinoma (Ca) of the gallbladder (28.7%) was the commonest aetiology followed by Ca pancreas (26.5%), choledocholithiasis (12.4%), cholangio Ca (10.8%) benign stricture (10.8%) and ampullary Ca (9.8%). A total of 167 subjects (44%) had high block while 213 (56%) had low block. Block at the porta hepatis was due to gallbladder Ca in 91% of patients. Ca pancreas was the cause of lower end block in 76% of patients.

Conclusion: SOJ, as seen in this large series of patients was most often due to malignant cause and gallbladder Ca was the commonest cause in North Indian patients. The clinician should utilize the ability of the ultrasound to diagnose the presence of obstructive jaundice and its location.