Exfoliated Tumor Cells in Intraluminal Lavage Samples after Colorectal Endoscopic Submucosal Dissection: A Pilot Study.

Endoscopic submucosal dissection involves dissecting manipulation performed with tumors in an exposed condition for a long period of time. Thus, there is a risk for implantation of tumor cells. The objectives of this study were to examine exfoliated tumor cells after colorectal endoscopic submucosal dissection and to elucidate the effectiveness of intraluminal lavage to remove these cells. The subjects were 8 patients who had undergone colorectal endoscopic submucosal dissection at our hospital between September and December 2012. A retrospective study was conducted on the cytological findings of intraluminal lavage samples in these patients. Seven of the 8 patients (88%) had exfoliated tumor cells in the lavage samples at the beginning of lavage. Only 3 patients (3 8%) had exfoliated tumor cells after lavage with 300 ml of water. A large number of tumor cells were thought to have exfoliated into the intestinal lumen after endoscopic submucosal dissection. Sufficient intraluminal lavage after colorectal endoscopic submucosal dissection is necessary to remove exfoliated tumor cells.