168 THE LARYNX, BRONCHI AND OESOPHAGUS TYPES OF TRACHEOSTOMY 1. Elective Temporary Tracheostomy. This is. performed as a planned procedure, usually under general anaesthesia, as a temporary stage in the patient's management. Examples ofthis are in the management of recoverable coma or of inflammatory lesions such as acute epiglottitis, or as a safety measure in a head and neck malignancy operation. 2. Permanent Tracheostomy. In an operation involving removal of the larynx, such as a laryngectomy or laryngopharyngectomy, the tracheal remnant is brought out on to the surface as a permanent mouth to the respiratory tract. 3. Emergency Trachestomy. Nowadays there ought to be very few indications for this—on occasion a patient will be seen first with a large laryngeal tumour and require an emergency tracheostomy; this, however, is a situation that would only occur once every 2 or 3 years. To have to do an emergency tracheostomy in conditions such as acute epiglottitis, respiratory failure, coma, etc. is a sign of poor forward planning in the management of the patient. It is usually done under local anaesthetic if it is a true emergency and this, to the inexperienced, is a difficult, dangerous operation. TRACHEOSTOMY TUBES 1. The Silver Jackson Tube. This is used for a temporary tracheostomy and consists of an outer tube and an inner tube which can be cleaned without disturbing the outer tube. It is inserted over an introducer. 2. Portex Tubes. These are also widely used and can be used cuffed or uncuffed. No introducers are used with them. There is no inner tube, but they are almost non-irritant. 3. Radcliffe Tube. This is a right-angled tube, not used with an inner tube, which is useful in a patient with a thick, fat neck. 4. Durham's Tube. This is a tube with an adjustabje^flange and can be made to fit any size of neck. TECHNIQUE OF TRACHEOSTOMY This is usually done with the patient intubated and positioned with a sandbag underneath the shoulders hi order to extend the neck and to pull as much trachea as possible into the operative site. A horizontal incision is marked with methylene blue two fingers breadth above the sternum (fig. 76). The incision is carried through the skin and subcutaneous tissue down to the strap muscles. These are separated in the midline, held aside with two retractors and the prevertebral fascia identified. This is then incised in a vertical direction, avoiding the inferior thyroid veins, and the thyroid isthmus is identified (Fig. 77). This latter structure is freed from the trachea, clamped, divided and oversewn with 3/0 silk. The tracheal rings are then seen and at this point the oricoM should be deliberately identified since to make an incision through the qicoid or first tracheal ring will cause larvngeal collapse and stenosis- A vertical incision is made through the tfoird and fourth rings and a semicircle of tracheal wall is removed from either side (Fig. 78). The appropriately-sized tracheostomy tube is inserted and the wound closed, b**t not tightly, with 4/0 silk sutures.