Pleural lavage with distilled water during surgery for esophageal squamous cell carcinoma

This study aimed to investigate cytocidal effects of hypotonic shock on esophageal squamous cell carcinoma (ESCC) cell lines, and to apply pleural lavage with distilled water to surgery for ESCC. Three human ESCC cell lines, TE5, TE9 and KYSE170 were exposed to distilled water, and morphological changes in ESCC cells were closely observed under a differential interference contrast microscope connected to a high-speed digital video camera. Further, serial cell volume changes after hypotonic shock were measured using a high-resolution flow cytometer. To investigate the cytocidal effects of hypotonic shock on ESCC cells, re-incubation of ESCC cells was performed after hypotonic shock. Additionally, the effects of 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), a Cl- channel blocker, during hypotonic shock were analyzed. Video recordings by high-speed digital camera demonstrated that hypotonic shock with distilled water induced cell swelling followed by cell rupture. Measurements of cell volume changes using a high-resolution flow cytometer indicated that severe hypotonicity with distilled water increased broken fragments of ESCC cells within 5 min. Re-incubation experiments demonstrated cytocidal effects of hypotonic shock on ESCC cells. Treatment of cells with NPPB increased cell volumes by the inhibition of regulatory volume decrease, which is observed during hypotonic shock, and enhanced cytocidal effects. These findings demonstrated the cytocidal effects of hypotonic shock on ESCC cells, and clearly support the efficacy of pleural lavage with distilled water during surgery for ESCC.