Lymph node yield following injection of patent blue V dye into colorectal cancer specimens

Aim: The study aimed to assess whether the ex vivo injection of patent blue V dye would increase lymph node yield in operative specimens of colorectal cancer. Method: A randomized controlled trial was carried out in which patients undergoing resection for colonic cancer were allocated to patent V blue or no patent blue V dye submucosal injection of the operative specimen. The number of lymph nodes found in each group was compared. Results: Between 1 January and 31 December 2008, 68 patients were randomized. Thirty-three patients received patent blue V dye and 34 did not. In the former group the median number of blue nodes identified was 11, compared with a median of 9 in the no dye group. After the application of Carnoy's solution lymph node count was 16 in each group. There was no significant difference between all these results. Conclusion: Ex vivo injection of patent blue V dye submucosally in a peritumour location did not increase the lymph node count or the percentage of specimens having more than 12 lymph nodes identified.