Since the advent of open tracheostomy efforts were made to devise a procedure which will enable access into the trachea without a surgical incision or a minimal surgical incision. Percutaneous tracheostomy was devised with just this purpose in mind.
Advantages of percutaneous tracheostomy:
1. It is a simple procedure
2. Very easy to perform under emergency situations
3. Can be performed easily on the bed side
4. Can be performed by paramedics
Evolution of percutaneous tracheostomy:
The first tracheostomy technique that did not require neck dissection was first described by Sheldon in 1957. He used a specially designed slotted needle to blindly enter the tracheal lumen. This needle served as a guide for the introduction of a stillete and a metal tracheostomy tube.
In 1969 Toyee refined this technique making it incisional rather than dilational. In this technique after the trachea was cannulated using a needle, the tracheostomy tube was loaded on to a stiff wire boogie that contained a small recessed blade. This boogie along with the tracheostomy tube was advanced through the needle tract thereby placing the tracheostomy tube inside the trachea. This procedure was fraught with risks and para tracheal insertions occurred commonly and hence did not become popular.
In 1985 Ciaglia perfected the technique of percutaneous tracheostomy which is currently gaining popularity. He named this procedure dilational subcricoid percutaneous tracheostomy. (PDT). This technique has undergone three significant modifications:
1. The tracheal interspace for cannulation has been moved down by two rings caudal to the cricoid cartilage. This was done to prevent the development of subglottic stenosis.
2. Routine use of fibreoptic bronchoscopy has been advocated.
3. The use of single bevelled dilator has been substituted by the use of multiple dilators.
The vital signs of the patient are continuously monitored during the procedure. The patient is ventilated with 100% oxygen during the whole procedure. The patient is sedated using a narcotic analgesic, and often a non depolarising neuromuscular blocker is used. The neck of the patient is extended to bring up the trachea closer to the skin. The vertex of the patient is properly supported.
A 2 cm skin incision is located at the level of 1st and the 2nd tracheal rings. The wound is then dissected bluntly using artery forceps. The existing endotracheal tube is then slowly withdrawn to a level just above the first tracheal ring, the needle is then inserted through the incision to penetrate the trachea between the second and the third tracheal rings. The J tipped guide wire is inserted through the needle till it hits the level of carina. The needle is then withdrawn. Bevelled plastic dilators are introduced over this guide wire and the opening is dilated to create a tracheostome. When the dilatation is adequate a special tracheostomy tube is inserted over the guide wire. The dilators can be used as obturators. In properly performed precutaneous tracheostomy the tracheostomy tube will pass through the isthumus of the thyroid, there will not be any significant bleeding because the procedure is purely dilatational.
Paul's modification of Ciaglia technique:
This modification was introduced in 1989. Paul advocated the use of fibreoptic bronchoscope through the endotracheal tube to facilitate percutaneous tracheostomy.
The advantages of this modification are:
1. Use of bronchoscope allows for correct placement of tracheostome.
2. It ensures that the guide wire is introduced in a midline position.
3. It prevents damage to posterior tracheal wall during introduction of needle.
4. It helps in video recording the whole procedure for instructional purposes.
The major disadvantages of this modification are:
1. It involves more time.
2. More trained personal and special equipments are needed.
3. The procedure is more expensive.
To reduce the operating time a single curved dilator (Blue rhino dilator) is utilised instead of multiple dilators. Since this dilator is soft and has a more physiologic curvature it does not cause extensive damage to the soft tissues and the tracheal walls.
This was first introduced in 1989 by Sachachner with an intention in facilitating a rapid tracheostomy. A special Rapitrach dilator was used. A rapitrach has two sharp blades designed in such a way that it slides over the guide wire and an opening is made when it is dilated. This procedure had a high incidence of damage to the membranous posterior tracheal wall. To avoid this complication in 1990 Griggs used a custom made forceps known as the Howard Kelly forceps. The tip of the forceps can be opened to create a tracheostome. In fact in all these methods the basic steps are the same but for modifications in the dilatation technique.
This was first describe by Fanconi etal. The major aim of this procedure is to prevent damage to the posterior membranous wall of the trachea. The dilatation in Ciaglia technique is directed in a downward direction causing significant anteroposterior compression of the tracheal wall. Sometimes this compression is sufficient to cause rupture of the membranous posterior tracheal wall. In this technique this excess anteroposterior pressure is avoided since the tracheostomy tube is pulled upwards through the larynx in an inside out manner. The procedure is similar to Ciaglia technique till the introduction of a guide wire through the first and the second tracheal interspaces. The similarity ends here. The guide wire is passed through the needle into the larynx in a retrograde fashion, infact it traverses coaxially alongside the endotracheal tube till it reaches the oral cavity from where it is pulled out using a Magill's forceps. The aim of the next step is to create a room for the tracheostomy tube to traverse the larynx since an endotracheal tube is already in position. To achieve this the existing endotracheal tube in position is replaced with a smaller endotracheal tube using the same guide wire as a guide. The J tip (oral cavity end) of the guide wire is then attached to a special trocar and tracheostomy tube assembly. The guide wire is pulled through its neck end. This pulls the trocar along with the tracheostomy tube through the larynx into the trachea. Here excessive tension to the posterior tracheal wall is avoided. When the trocar causes tenting of skin in the neck a small incision is made over this tenting and the trocar is delivered out along with the tracheostomy tube. The endotracheal tube is removed, and the tracheostomy tube is anchored in place.
Since these procedures involve an already intubated patient it calls for excellent coordination between the surgeon and the anaesthetist.
Routine pre operative ultrasound examination of the neck is a must because it will identify the site of an unusually large inferior thyroid veins which could cause troublesome bleeding during the procedure.
1. A patient already in intense stridor.
2. Laryngeal malignancies
3. Short neck individuals
4. When proper trained personal are not available
5. Large thyroid gland
6. When ultrasound reveals an abnormally large inferior thyroid vein.