Real-time and the in vivo detection of minute cancer invasion to the portal-superior mesenteric vein using contact endoscopy during a pancreatic cancer resection

The portal-superior mesenteric vein (PV/SMV) is occasionally involved by a microscopic level of cancer invasion from pancreatic cancer even when it seems to be intact by a macroscopic inspection during surgery. Therefore, contact endoscopy, with which a high-magnification image of the methylene blue–stained PV/SMV wall can be obtained in vivo, was used during pancreatic cancer resections. Contact endoscopy succeeded in detecting minute cancer invasion and identified the precise location on the isolated PV/SMV wall in 3 out of 11 patients whose PV/SMVs had been disclosed from the pancreatic tumors. The 3 positive patients underwent an additional resection of the PV/SMV, and appropriate ranges of PV/SMV resection were confirmed by the postoperative histology. Thus, contact endoscopy is considered a promising modality for making a real-time diagnosis on the precise location of minute cancer, without requiring any tissue sampling.