Vital Staining Role in Resection and Reconstruction of Tongue Cancers with Free Flap - A Comparative Study

The purpose of this study is to compare and infer the most suitable dye for visualisation of ipsilateral and contralateral sentinel lymph nodes (SLNs), positive, negative outcomes, sensitivity, their specificities and visualisation of anastomosed blood vessels in microvascular reconstruction of tongue cancers.

This is a prospective in vivo comparative study involving twenty patients diagnosed with squamous cell carcinoma of the tongue treated with wide excision of primary tongue tumour, modified functional neck dissection and microvascular reconstruction with radial forearm free flap. Consecutive random allocation was done into two groups with ten patients each. Patients were injected with methylene blue as the first group and near-infrared fluorescence indocyanine green (ICG) into the second. The patients were evaluated intraoperatively regarding the better dye in methylene blue and ICG for identification of ipsilateral and contralateral SLNs, their positive, negative outcomes, sensitivity and specificities. Apart from these, in cases of group B, after microvascular transfers, ICG is used for visualisation of anastomosed vessels to prevent abnormal perfusions, leaks and post-flap failures. Descriptive statistics, independent samples t-test, and Chi-square were used for statistical analysis.

The present study revealed ICG being the better dye in the parameters mentioned.

Lymph node yield in neck dissection is a prognostic factor in oral cancers. ICG is inferred as the better dye for identification of SLN with 100% outcomes and in blood vessel visualisation after microvascular free tissue transfers. It is also useful in identifying positive contralateral sentinel nodes, which is helpful in undertaking bilateral neck dissections related to tongue carcinoma.