Fig. 2.

Typical example of downstaging after IOUS. a CT imaging at time of diagnosis (before biliary stent placement): involvement of the superior mesenteric artery (SMA; 270–360°) and superior mesenteric vein (SMV; 90–180°). Resectability status at diagnosis: locally advanced (LAPC). b CT imaging after completing preoperative chemoradiotherapy: persistent infiltration was seen surrounding the SMA (> 270°) and the superior mesenteric vein (90–180°), essentially unchanged when compared with initial imaging. Staging after preoperative therapy: LAPC. c Intraoperative ultrasound (IOUS): at most, 90° contact with the superior mesenteric vein was visible and no involvement of the superior mesenteric artery. Staging after IOUS: resectable. Time between last preoperative imaging and IOUS: 35 days