Abstract No. 561 Percutaneous endoluminal brush cytology in patients suspected of malignant biliary obstruction: Experience from a tertiary cancer center in India

Abstract

To evaluate endoluminal brush cytology during percutaneous biliary drainage in patients suspected of malignant biliary obstruction. From January 2010 to December 2016, 106 consecutive patients with obstructive jaundice secondary to suspected malignant biliary obstruction underwent 136 endoluminal brush cytology procedures, during or after percutaneous transhepatic biliary drainage in presence of on-site cytologist. The data was collected retrospectively and analysed. The lesions involved the common bile duct (n-21), common hepatic duct (n-22) and hilum with right or left intrahepatic ducts (n-63). In each patient, upto three (mean-1.3) brush cytology specimens were taken with 8F double lumen brush. Definitive diagnosis in each case was established by the Brush cytology, exploratory laparotomy, biopsy/cytology from any other metastatic site or combination of tumour markers, radiological or clinical suspicion and increase in size or metastasis in follow-up. Statistical analysis was performed using chi-square test and Z-test of significance to compare sensitivity and p-value ≤0.05 was considered statistically significant. 66 out of 106 patients had correct diagnoses of malignancy on brush cytology. 3 diagnoses proved to be true-negative & 37 were false-negative. 9 out of 22 patients (40.1%) had malignancy diagnosed in 2nd attempt and 1 of 3 patients (33.3%) had malignancy diagnosed with 3rd attempt. Diagnostic sensitivity and specificity brush cytology for malignant nature of biliary strictures was 64.1% and 100% respectively with accuracy of 65.1%. The sensitivity of brush cytology was highest in proximal hilar block 67.8% as against 38.5% noted for lower CBD block, this difference was statistically significant (p-value ≤0.034). Anastomotic site recurrence had a sensitivity of 46.1% in diagnosing malignant nature of disease. No complications were related to the procedure. Percutaneous endoluminal brush cytology is relatively accurate procedure that is safe & easy to perform through a transhepatic biliary drainage tract. Sensitivity to diagnose malignant stricture was higher in primary and proximal hilar block as against lower CBD block & anastomotic site strictures.