The tracheal mucosa microvasculature and microcirculation. Intravital microscopic observations in rabbits and a histologic study in man.

A method for the intravital microscopic study of the tracheal mucosal microcirculation in the rabbit is described. A low tracheostomy is performed for ventilation, while a hole cut in the ventral portion of the trachea cranial to the tracheostomy is used for observations. The trachea is immobilized by a fixation device. Microscopic observations are made with a Leitz stereo microscope. The microvasculature of the rabbit tracheal mucosa is characterized by centripetally arranged arterioles which subdivide into a fairly sparse capillary network at the mucosal surface. The capillaries drain into venular networks at different levels of the mucosa and collect finally into circumferentially arranged veins which run mainly between the cartilages. For comparative purposes the microvasculature of the human tracheal mucosa has been analysed in clarified (Spalteholz) preparations. This investigation shows that the microvascular architecture is principally the same in the human and rabbit tracheal mucosa. There is, however, a much denser capillary network in the human tracheal mucosa.