High tracheostomy is done in:-

Tracheostomy has been divided into high, mid or low. 1. High tracheostomy is done above the level of thyroid isthmus (isthmus lies against II, III and IV tracheal rings.) It violates the First ring of trachea. Tracheostomy at this site can cause perichondritis of the cricoid cailage and subglottic stenosis and is always avoided. Only indication for high tracheostomy is carcinoma of larynx because in such cases, total larynx anyway would ultimately be removed and a Fresh tracheostomy made in a clean area lower down. 2. Mid Tracheostomy is the preferred one and is one through the II or III ring and would entail division of the thyroid isthmus or its retraction Upwards or downwards to expose this pa of trachea. 3. Low tracheostomy Is done below the level id isthmus. Trachea is deep at this level and close To several large vessels; also, there are difficulties with tracheostomy tube Which impinges on suprasternal notch.