The structure damaged in High Tracheostomy ?
Thyroid isthmus
Aoic knuckle
First tracheal ring
Recurrent laryngeal nerve
Ans. is'c' i.e., First tracheal ring(Ref: Dhingra dle p' 317)High tracheostomy: Performed above the level of thyroid isthmus which lies against II, III and IV tracheal rings:Indicated in carcinoma larynx when laryngectomy is anticipated.Drawback : tracheostomy at this point violates the 1st ring of trachea and causes perichondritis of the cricoid cailage and subglottic stenosis, so it is better avoided.