Left hepatectomy with caudate lobe resection using the methylene blue staining technique for bismuth IIIb hilar cholangiocarcinoma

Left hepatectomy with caudate lobe resection has been widely accepted as the standard treatment for bismuth IIIb hilar cholangiocarcinoma (1-6). However, there is no clear boundary between the right caudate lobe and the right posterior section. The methylene blue staining technique are commonly used to delineate the margin of the relevant hepatic segment for anatomic hepatectomy (7). Herein, we described this technique to demarcate the boundary between the caudate lobe and the right posterior lobe for an en bloc resection of the tumor and improve the R0 surgical margin.