Adult Chest Surgery

Chapter 45. Tracheostomy 

Tracheostomy is one of the most commonly performed procedures in surgical practice. An emergent intervention dating back to 1500 BC,1–3 until recently, tracheostomy was used solely to relieve acute upper airway obstructions. Polio and the advent of modern ventilators in the twentieth century made tracheostomy largely a routine elective procedure for patients dependent on ventilatory assistance. This chapter describes the techniques and associated risks and benefits of the procedure.

INDICATIONS

Tracheostomy continues to be indicated for relief of upper airway obstruction, including intermittent obstruction such as occurs in sleep apnea, although cricothyroidotomy is preferred in the acute emergency situation. More tracheostomies today, however, are performed electively in the critical care setting to facilitate pulmonary toilet and ventilatory support for chronically ventilated patients. Tracheostomy is superior to prolonged translaryngeal intubation in many ways (Table 45-1). Tracheostomy improves patient comfort, leading to decreased requirements for analgesia and thereby facilitating ventilatory weaning. It provides a more secure airway, which, in turn, permits greater patient mobilization because the risk of inadvertent extubation is decreased. It reduces the incidence of vocal cord injury and subglottic stenosis, as well as the rate of sinusitis. Airway resistance is also reduced over the short tracheostomy in comparison with the longer endotracheal tube. Pulmonary toilet and oral hygiene are improved, and it permits the use of fenestrated devices that provide the potential for speech.4–8 Despite these advantages, considerable debate remains over the ideal timing of tracheostomy. In principle, tracheostomy should be considered for any critically ill, intubated patient in whom extubation is not immediately foreseeable, after the patient has spent a "reasonable" length of time on the ventilator. Defining reasonable forms the basis of the controversy. In the 1960s, a reasonable length of time was considered to be as few as 3 or 4 days because of the high rate of complications associated with the use of rigid, low-volume, high-pressure endotracheal cuffs during prolonged translaryngeal intubation. After the introduction of high-volume low-pressure endotracheal cuffs in the 1970s, complication rates decreased, and it became reasonable to keep patients with endotracheal intubation for longer periods. Translaryngeal or endotracheal intubation now may be appropriate for periods up to 3 weeks, particularly if the patient objects to a tracheostomy or if there are contraindications or other risks.4–6,9–12

Table 45-1. Major Risks and Benefits of Tracheostomy

Risks

Benefits

Tracheoinnominate fistula

Tracheoesophageal fistula

Tracheal stenosis from granulation tissue

Stomal infection or hemorrhage

Tracheomalacia

Swallowing dysfunction

Patient comfort

Increased airway security

Improved pulmonary toilet

Facilitated ventilatory weaning

Decreased risk of subglottic stenosis and vocal cord injury

Decreased rate of sinusitis

Decreased airway resistance

Improved oral hygiene

Potential for speech

 

Although tracheostomy is a safe procedure, it is neither benign nor without risk. Morbidity for tracheostomy ranges from 4% to 10%, whereas mortality is less than 1%.4–6 Complications include infection at the stoma site, stomal hemorrhage, granuloma formation that can lead to obstruction, tracheal ring rupture, tracheoinnominate fistula (TIF), tracheoesophageal fistula, tracheal stenosis, tracheomalacia, and swallowing dysfunction that may be permanent even after decannulation4,5,7–9,13,14 (see Table 45-1). Recent outcome studies that compare early versus late tracheostomy in the setting of trauma or medical illness are inconclusive and often flawed with multiple internal design errors.4–6,10,12,15 The optimal time for tracheostomy must account for numerous factors, including the likelihood of extubation, the chance of multiple reintubations, the probability of complications secondary to laryngeal intubation, and the wishes of both the patient and the family. Although no strict timelines exist, current practice recommends tracheostomy in any patient who has been intubated for more than 1 week and is not likely to be extubated within the next week or for patients in whom tracheostomy would improve pulmonary toilet and decrease sedation requirements, thereby facilitating ventilatory weaning.4–10,13

Relative contraindications to tracheostomy include poor oxygenation that requires high levels of positive end-expiratory pressure and ventilatory support that prohibits safe transport or prevents the patient from safely tolerating apnea during exchange of the endotracheal tube for the tracheostomy appliance. Other relative contraindications include bleeding disorders, anatomic restrictions such as body habitus, "high" passage of the innominate artery at the level of the suprasternal notch, or high vasopressor requirements that prevent adequate sedation during the procedure secondary to hypotension.

Choice of Tracheostomy Appliance

The selection of tracheostomy appliance is based on a thorough knowledge of the specific features of each device in relation to the patient's needs. Pertinent features include inner and outer diameters, length (of both proximal and distal portions of the device), angle, and presence or absence of an inner cannula or fenestrations. The size of the tracheostomy appliance should be large enough to provide adequate bronchoscopic pulmonary toilet if this is a consideration, bearing in mind that larger cannulas lead to higher rates of tracheal stenosis and smaller cannulas are associated with increased airway resistance.5,6 A 7- or 8-mm-diameter (inner circumference) tube typically is used because it is the smallest diameter that will allow for adequate pulmonary toilet. Appliance length usually is fixed but adjustable. Adjustable alternative-length devices are available for patients with anatomic features that do not accommodate standard-length devices. For example, the cannula may be too short, such that it abuts the posterior tracheal membrane, or it may be too long, such that it abuts the carina, leading to partial airway obstruction. The optimal length should place the end of the tracheal cannula 3–4 cm above the carina. The high-volume low-pressure cuff is currently preferred because it leads to fewer airway complications while providing substantial airway resistance to airflow around the cuff. When the tracheostomy is still required after the cuff is no longer needed for ventilatory support, the tracheostomy appliance should be replaced with a cuffless or fenestrated variety. If there is sufficient airflow around the deflated cuff, patients with intermittent ventilatory requirements can be fitted with a one-way Passey-Muir valve to permit speech when the patient is not being ventilated. Extreme caution is required, however, because the Passey-Muir valve increases the airway resistance. Failure to deflate the cuff before attaching the one-way valve can result in respiratory failure and death of the patient. Fenestrated appliances decrease airway resistance by permitting airflow through the fenestrations, which, in turn, allows the patient to speak when the tracheostomy is capped and the fenestrations are open. However, a closed inner cannula and inflated balloon must be present to mechanically ventilate these patients, and the fenestrations can make suctioning more difficult and increase granulation tissue in the airway in some instances. Inner cannulas decrease the risk of tracheal occlusion secondary to the accumulation of secretions within the outer cannula. For this reason, inner cannulas are preferred for permanent or long-term tracheostomies. Selecting the appropriate appliance requires careful consideration on a case-by-case basis. When patients have recovered sufficiently and no longer need a tracheostomy, the appliance is either removed completely or replaced with a smaller, noncuffed variety for pulmonary toilet. The stoma is covered, and the patient is instructed to hold the stoma closed during coughing. With time, most tracheostomies close spontaneously, although there occasionally can be excessive granulation tissue around the stoma site requiring surgical debridement and closure in the OR.

TECHNIQUES

Surgical Tracheostomy

Surgical tracheostomy usually is performed under general anesthesia in the OR. The key steps are outlined in Table 45-2. 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 45-2. Ten Steps of a Surgical Tracheostomy

1.     Position 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 1–2 cm above the suprasternal notch (Fig. 45-1). 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 less than ideal 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.

Figure 45-1.

 

Tracheostomy. A. Location of incision 1–2 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. 45-1C ). 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 TIF, 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 direction 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

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.7–9,13,18–20Dilational 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 Scoop catheters, whereby patients with end-stage lung disease can receive higher FIO2 support via endotracheal delivery than is possible via nasal cannula.

Cricothyroidotomy

Cricothyroidotomy typically is performed in emergency situations when translarygneal 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 though a vertical midline neck incision or 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 48–72 hours if ventilatory support airway access will be required.

COMPLICATIONS

The various described techniques of tracheostomy are associated with similar complications. Bleeding and infection are the most common problems. Bleeding can occur from multiple sources. Minor bleeding can originate from small vessels of the skin or the tracheal mucosa. Most such bleeding resolves with gentle pressure and time. Occasionally, cautery is required. Bleeding that occurs 2–3 weeks after a tracheostomy, especially if arterial in nature, is worrisome for a TIF. The incidence of this complication is less than 1%, but it can be lethal if not treated promptly.4,6,11,22,24 Often the first indication of a TIF is a minor "sentinel" bleed that heralds the subsequent massive hemorrhage that occurs if the fistula is not diagnosed and repaired immediately. Diagnosis of TIF is best done by bronchoscopy through the mouth, which often reveals bleeding either from the site where the balloon has eroded into the artery or more often from the lower edge of the stoma where a low tracheal cannula has eroded into the artery. Other diagnostic methods that can be useful are CT scanning of the neck with intravenous contrast material or MRI, although direct examination in the OR is usually the safest and fastest approach if there is sufficient concern for TIF. Immediate temporizing management of an actively bleeding TIF requires hyperinflation of the tracheal cuff if the fistula is secondary to cuff erosion (Fig. 45-2). If unsuccessful, or if the fistula is the result of cannula erosion, orotracheal intubation should be performed, followed by removal of the tracheal cannula and insertion of a digit into the stoma to apply manual pressure against the sternum, thereby tamponading the bleeding fistula on the way to the OR. Operative repair of the TIF is required immediately, occasionally with the aid of cardiopulmonary bypass. Particularly in cases of infection, repair may be best accomplished by division and ligation of the innominate artery. Similarly, a tracheoesophageal fistula can develop and typically presents with either gastric dilatation or aspirated tube feeds or food through the tracheostomy. These are best diagnosed by bronchoscopy. If small, these can be temporized by esophageal or airway stenting before definitive surgical repair. Ironically, tracheal stenosis also can result from a tracheostomy, although this is rare and often difficult to distinguish from the injury that occurs secondary to prolonged translarygneal intubation. Symptomatic tracheal stenosis in patients who have been decannulated often requires tracheal resection if dilation techniques fail to resolve symptoms. Other minor complications include local infection of the tracheostomy stoma site, which usually resolves with proper skin care and antibiotics for cellulitis.

Figure 45-2.

 

Etiology and management of tracheoinnominate fistula. Tracheoinnominate fistula may arise from erosion of the tracheostomy balloon into the innominate artery posteriorly (A) or direct erosion of the tracheostomy cannula into the innominate artery (B). In both cases, control of the airway with ventilation and protection of the lungs during transport to the OR are the principal goals.

SUMMARY

Tracheostomy is a common surgical procedure that is performed mainly to facilitate the care of chronically ventilated patients. Standard surgical and percutaneous techniques are described to perform a tracheostomy. If performed in appropriate clinical settings by those with adequate experience, both approaches are associated with a low morbidity. Similar complications can occur as a result of tracheostomy and prolonged ventilatory support regardless of the surgical approach, and therefore, all surgeons should be familiar with the diagnosis and the management of these complications.

EDITOR'S COMMENT

The indications for tracheostomy include (1) management of the critically ill patient to facilitate weaning, (2) bypass of airway obstruction, (3) airway protection for chronic aspiration, and (4) as part of a surgical extirpative procedure such as laryngectomy. I prefer to incise above the third ring transversely, cut the ring anteriorly, grasp with a snap each of the lateral portions of the third ring, elevate them to the skin, and then advance the tracheostomy under total control. This prevents the most feared complication of tracheostomy—losing the airway. I do not place sutures on the trachea because the message to our residents is that should the tracheostomy tube fall out, the patient should be intubated via the orotracheal route, which is safer and less likely to result in a mediastinal dissection.

–RB

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