Ex vivo intravascular methylene blue instillation in oesophagectomy and gastrectomy specimens and its implication in tumour histopathological assessment.

Surgical resection and lymphadenectomy are the mainstay of curative treatment for oesophagogastric cancer. In this study we evaluate the results of intravascular methylene blue injection into oesophagectomy and gastrectomy specimens as a tool to increase lymph node detection. A prospective and descriptive study was run on 24 patients (11 oesophagus, 13 stomach cases). The most frequent histological type was adenocarcinoma (oesophagus 29.2%, stomach 90.9%). All patients with oesophageal cancer received neoadjuvant treatment, compared to 8 with gastric cancer. The anatomopathological analysis of oesophagectomies showed a median of 42 isolated nodes, compared to 46 in gastrectomies. In oesophageal cancer, a total of 8 (72.7%) patients did not show lymphatic involvement, whereas, in gastric cancer patients, 76.9% of patients had lymph nodes, with a median number of positive nodes of 3 (RIC = 0.5-7). Instillation of methylene blue enables a large number of nodes to be analysed and could therefore improve staging, treatment and prognosis for patients with oesophagogastric cancer.