Surgical tracheostomy usually is performed under general anesthesia in the OR. The key steps are outlined in Table 54-2. The patient is placed in the supine position with the neck extended. Neck extension is facilitated by placing a towel roll under the patient's shoulders. Neck extension facilitates tracheostomy by elevating the trachea out of the thorax into the operative field. Care must be taken to avoid hyperextending the neck. In younger patients, overelevating the trachea creates the possibility of placing the tracheostomy too low in the trachea. Trauma victims and elderly patients are also particularly vulnerable to hyperextension injuries. Neck extension should not be performed in patients with a history of known or suspected cervical spine injury, and it may not be possible in patients with severe kyphosis, arthritis, or spinal fusion. In these patients, tracheal exposure can be aided by using a tracheal hook or by dividing the thyroid isthmus.
Table 54-2Ten Steps of A Surgical Tracheostomy ||Download (.pdf) Table 54-2Ten Steps of A Surgical Tracheostomy
|1. Position the patient supine with neck extended. |
2. Make a transverse skin incision 1–2 cm above the suprasternal notch and below the cricoid cartilage.
3. Divide the platysma transversely until the midline strap muscles are reached.
4. Separate the strap muscles in the midline to identify the pretracheal fascia.
5. Divide the thyroid isthmus or reflect it superiorly with retractors to approach the anterior trachea.
6. Count the tracheal rings from the cricoid cartilage, and place stay sutures laterally at the second or third tracheal ring.
7. Minimize Fio2, incise the ring interspace with a number 15 blade, avoid cautery, and dilate the ring interspace with a tracheal dilator.
8. Place the prelubricated and pretested tracheostomy appliance into the airway and rotate it into position under direct vision.
9. Confirm ventilation with anesthesia by auscultation and by measuring end-tidal Pco2. Consider bronchoscopic verification at the end of the case.
10. Secure the tracheostomy appliance to the skin with sutures.
After the sterile operative field is prepared with standard surgical techniques, a 2- to 3-cm transverse incision is made 1 to 2 cm above the suprasternal notch (Fig. 54-1). The actual location of the incision may vary depending on anatomic features, such as the location of the cricoid cartilage or a history of prior neck surgery or trauma. After the subcutaneous tissues and the platysma are divided transversely, the anterior superficial cervical fascia is divided longitudinally, which brings the strap muscles into view. The median raphe between the strap muscles (i.e., sternohyoid and sternothyroid) is developed, with hemostasis of the small venous branches by means of cautery. This brings the thyroid gland and pretracheal fascia into view. The pretracheal fascia and tissue below the thyroid isthmus are incised, bringing the anterior surface of the trachea into the operative field. Occasionally, it is necessary to divide the thyroid isthmus, but usually it can be elevated away exposing the superior portion of the trachea with the aid of retractors. When neck extension is not optimal or cannot be performed safely, the isthmus can be divided between clamps and suture-ligated to improve tracheal exposure. The thyroid internal mammary artery, if present and in the operative field, is ligated and divided at this time.
Tracheostomy. A. Location of incision 1 to 2 cm above the suprasternal notch. B. Division of the median raphe between the strap muscles with identification of the thyroid isthmus. C. Opening made in the trachea at the third tracheal ring. Under direct visualization, the endotracheal tube is withdrawn to just above the tracheal opening before attempting to insert the tracheostomy appliance.
After ensuring complete hemostasis of the operative field, several preparative steps should be taken before performing the tracheostomy: (1) The tracheostomy appliance, which has been selected on the basis of indications for use and size of the trachea, is placed on the field, (2) the tracheostomy cuff is tested under water to confirm that it is intact, (3) the tracheostomy appliance is well lubricated, and the tracheal obturator is inserted into the appliance, (4) the surgeon confirms that the tracheal rings have been identified and are readily accessible, and (5) before the operation begins, the surgeon also should confer with the anesthesia team to ensure that the airway has been suctioned and is ready for airway exchange.
Tracheal exposure in obese patients or in those with suboptimal neck extension can be optimized further using the tracheal hook to secure the superior trachea near the cricoid cartilage and to elevate the trachea superiorly. Traction sutures also can be placed laterally around the second and third tracheal rings to elevate the trachea superiorly and anteriorly. These sutures also can be used in the immediate postoperative period to facilitate reinsertion of the tracheostomy appliance if it becomes inadvertently dislodged.
After the tracheal rings are counted and proper visualization of the trachea is ensured, a number 15 blade is used to incise the space horizontally between the second and third tracheal rings. Most surgeons subsequently divide the third ring in the midline (cruciate) bilaterally, creating a Bjork flap,16,17 and excise the flap, making a small hole in the trachea (see Fig. 54-1C). Proper positioning of the tracheostomy is critical. The location of the tracheostomy is based on identification of the third tracheal ring. It is impossible to establish a set distance from the suprasternal notch because the trachea is a mobile structure. High placement of the tracheostomy can lead to injury of the cricoid cartilage and subsequent subglottic stenosis. Low placement predisposes to the development of tracheoinnominate fistula, which results when the tracheostomy tube or cuff lies against the innominate artery. Low placement also causes the tracheostomy appliance to abut the carina, which predisposes to granulation tissue formation with subsequent potential for airway obstruction. Ventilation is held, O2 is minimized, and Bovie cautery is avoided while the trachea is opened because of the risk of causing an airway fire.
When both the anesthesiologist and surgeon are ready to place the tracheostomy, the endotracheal tube is slowly removed by the anesthesia team with direct visualization by the surgeon until the tube is above the tracheostomy. (If a fire occurs, the oxygen must be turned off and the endotracheal tube and tracheostomy removed immediately and taken away from the patient and operative field.) The tracheal opening is enlarged by gentle dilation, and the tracheostomy tube is placed laterally through this opening into the trachea under direct vision and rotated into the correct position with extreme care to avoid a false anterior passage or injury to the membranous portion of the trachea. The cuff is inflated and ventilation resumed at the previous Fio2 requirement. Proper placement of the tracheostomy tube is confirmed by chest expansion, auscultation, ease of ventilation, and confirmation of end tidal of Pco2. The tracheostomy tube is secured to the skin using nonabsorbable sutures in all four quadrants, in addition to placing a tracheal tie around the neck. Bronchoscopy is performed routinely at the end of the procedure to confirm proper placement of the tracheostomy tube and to clear any secretions or blood that may have accumulated in the airways during the procedure.
Percutaneous tracheostomy techniques, which can be performed at the bedside, reportedly saving the cost of OR time, have gained in popularity. Three percutaneous techniques have been described: (1) a translaryngeal technique, (2) a dilation technique using forceps, and (3) a dilation technique using serial dilators in Seldinger fashion. This section describes the third technique only because it is performed most commonly.7-9,13,18–20 Dilational percutaneous tracheostomy with the aid of serial dilators was described originally in 1969 but modified and popularized by Pasquale Ciaglia in 1985.21 Relative contraindications for this procedure include an airway emergency, obesity with an inability to palpate landmarks, an enlarged thyroid, and prior tracheostomy or neck surgery. Patients undergoing this procedure are ventilated with 100% oxygen and typically given a nondepolarizing neuromuscular blocker in addition to narcotic analgesics and sedatives. The patient is placed supine with the neck in extension, and the surgical field is prepared. A 1-cm skin incision halfway between the cricoid cartilage and the suprasternal notch is made to permit passage of the dilators, although a traditional tracheostomy incision can be made with dissection of subcutaneous tissues to better define tracheostomy positioning. A bronchoscope is inserted through the endotracheal tube, and the endotracheal tube is withdrawn from the airway and placed above the first tracheal ring. An 18-gauge needle then is inserted into the space between the first and second ring under bronchoscopic guidance. Using Seldinger technique, a J-tube guidewire is placed through the needle into the airway, and the needle is withdrawn. The tract is now dilated with sequential dilators over the guidewire or with a single large curved dilator, as has been advocated by some, with bronchoscopic visualization.8,18,19 When the tracheal opening has been dilated to an appropriate size, a tracheostomy tube is placed through the opening over the guidewire and subsequently secured once placement is confirmed by the bronchoscope. Multiple variations of this basic technique have been described, some without use of a bronchoscope. We advocate bronchoscopic guidance in our practice, however, because it prevents technical misadventures, such as impalement of the endotracheal tube, puncture of the posterior membranous trachea, or malposition of the tracheostomy.
Numerous studies have compared the relative benefits of percutaneous tracheostomy versus standard surgical techniques. Most of these studies are difficult to interpret because they are nonstandardized and combine various percutaneous techniques. Several recent studies comparing standard surgical techniques with dilational percutaneous tracheostomy suggest lower rates of peristomal bleeding and infection and potential cost benefits with percutaneous technique.7-9,13,15,18-20,22,23 Other studies have not shown these benefits, and increased complications have been reported often with percutaneous techniques. The likely scenario is that with proper patient selection, surgical expertise, and clinical setting, percutaneous techniques are equivalent to standard surgical techniques in a subset of patients.
The minitracheostomy is an extension of the serial dilation technique and is advocated by some for the management of excessive pulmonary secretions. Originally developed by Matthews and Hopkinson in 1984, it involves the placement of a small 4-mm tracheostomy cannula through the cricothyroid membrane into the trachea.6,14 The procedure is performed usually in sedated but awake patients using local anesthesia with the placement of a small incision over the cricothyroid membrane and subsequent cannulation of the membrane with an introducer and the small tracheostomy catheter. Minitracheostomies also may be placed at the end of major thoracic procedures in patients in whom secretions are anticipated to be a problem or in critical care patients in whom retained secretions are known to be a problem. A similar procedure is used for placement of subcutaneous original oxygen protocol (SCOOP) catheters, whereby patients with end-stage lung disease can receive higher Fio2 support via endotracheal delivery than is possible via nasal cannula. However, the SCOOP catheter is usually placed below the cricoid.
Cricothyroidotomy typically is performed in emergency situations when translaryngeal intubation has failed or is not possible. Although tracheostomy can be performed in this setting, cricothyroidotomy is preferred because of the simplicity and rapidity with which the technique can be performed compared with tracheostomy. The procedure is performed either through a vertical midline neck incision or through a horizontal incision centered on the palpated cricothyroid membrane once the neck is prepared in a sterile field. A vertical incision is advocated by some to avoid injury to the anterior jugular veins because bleeding may obscure the field and make the procedure more difficult. Others advocate a horizontal incision because it is the most familiar approach for practitioners accustomed to performing standard tracheostomies. Regardless of the incision chosen, exposure is facilitated by placement of a towel roll under the shoulders to extend and hence displace the trachea superiorly and anteriorly. Once the skin incision has been made, blunt dissection is used until the cricothyroid membrane is reached. The membrane then is incised and gently dilated to facilitate the passage of a small endotracheal tube or tracheostomy tube, if available. Placement of a tracheal hook below the thyroid cartilage may provide better exposure of the cricothyroid membrane and allow easier cannulation. Care should be taken to avoid injury, especially fracture of the cricoid ring, because this can require subsequent surgical reconstruction. Once the tube position is confirmed, visually by chest motion and by auscultation and end-tidal Pco2 return, the tube is secured. Cricothyroidotomy can be performed electively through a horizontal incision as a means of permanent airway access, but this usually is not done because cricothyroidotomy has been associated with a higher rate of subglottic stenosis. Hence, although controversial, an elective cricothyroidotomy usually is converted to a standard tracheostomy in 48 to 72 hours if ventilatory support airway access will be required.