In situ identification of normal visceral tissues using contact telescopicmicroscopy

Objectives: To improve the intraoperative anatomic identification of normal tissues during surgery using histologic-like criteria. Study Design: A con tact telescope was used to identify normal visceral tissues in an animal mo del using pigs and dogs during routine human surgical procedures. Methods: Tissues that could be identified grossly were stained topically with methyl ene blue and then examined with the contact telescope. The histologic appe arance of these tissues with the contact telescope was correlated with rout ine histologic hematoxylin and eosin stains obtained after such tissues wer e excised. Results: Normal tissues, such as fat, blood vessels, muscle, and parathyroid tissue, can be identified reliably in animals and humans. The contact telescope appears to be able to differentiate between a variety of visceral tissues in the neck and may become useful for practical differenti ation between tissues during surgery.