Introduction
- 1.
Airway protection is the most fundamental role of the mammalian larynx. (See Additional Sources for in-depth discussion.)
- 2.
For some patients, laryngeal function is compromised by disease processes to the extent that its airway protection role becomes inadequate in preventing aspiration.
- 3.
Chronic aspiration can be managed in most patients with alternative feeding, tracheostomy for pulmonary toilet, and oral care ( Box 21.1 ).
BOX 21.1
Nonsurgical Strategies
Nasoenteric tube feeding (or gastrostomy)
Nothing by mouth
Postural feeding technique
Swallowing therapy
Adjunctive Surgical Procedures
Cricopharyngeal myotomy
Gastrostomy/feeding jejunostomy
Tracheostomy
Vocal cord injection or thyroplasty for vocal cord medialization
Definitive Surgical Procedures
Glottic closure
Laryngotracheal separation
Laryngeal stenting
Narrow-field laryngectomy
Supraglottic closure
Tracheal flap closure
Tracheoesophageal diversion
Treatment of Morbid Aspiration
- 4.
Occasionally patients cannot be managed satisfactorily by conservative measures. A variety of surgical strategies can be used (see Box 21.1 ).
- 5.
Among the surgical strategies, the most definitive, straightforward, and acceptable procedure is laryngotracheal separation (LTS) ( Fig. 21.1 ).
Fig. 21.1
Laryngotracheal separation.
The proximal trachea is closed as a blind pouch.
From Eibling DE, Bacon GW, Snyderman CH: Surgical management of chronic aspiration. Adv Otolaryngol Head Neck Surg 6:108, 1992.
Key Operative Learning Points
- 1.
Decision making regarding surgical intervention with LTS is more difficult than the procedure itself.
- 2.
The anatomy of the tracheoesophageal party wall facilitates the safe performance of LTS in that a layer of loose areolar tissue separates the membranous posterior wall of the trachea from the esophagus.
- 3.
The posterior wall of the trachea is a fibrous layer contiguous with the perichondrium of the tracheal rings and the inter-ring connective tissue that permits circumferential dissection of the trachea.
- 4.
Removing and weakening tracheal rings permits closure of the proximal stump of the trachea.
Preoperative Period
History
- 1.
History of present illness
- a.
Etiology of aspiration (See Falestiny in Additional Sources for more in-depth discussion.)
Temporary or long-term?
Treatable primary disease process?
Local (laryngopharyngeal) or neuromuscular?
- b.
Episodes of pneumonia?
Minimal (mild pneumonitis) or severe
Number of episodes?
Courses of antibiotics? Colonized with resistant organisms?
- c.
Prior or current tracheostomy?
- d.
Feeding strategies?
- e.
Weight loss/inanition?
- a.
- 2.
Past medical history
- a.
Onset and progression of primary illness
- b.
Comorbidities
- c.
Anticipated progression of primary illness and comorbidities
- d.
Current admission status (hospital, long-term care, nursing home)
- e.
Expected survival duration?
- f.
Patient and family goals of care for remaining life
- a.
Physical Examination
- 1.
General—degree of frailty, nutritional and cognitive status, communication skills, open wounds in head and neck region
- 2.
Laryngopharyngeal endoscopic examination
Vocal cord mobility—is there any motion?
Glottic closure—Can the glottis close to protect the airway? Is there an alternative strategy based on enhancing closure?
Pooling of secretions. Often extent of secretions precludes examination
- 3.
Oral cavity
Is the patient able to handle his or her secretions?
Tongue and palate mobility. Even if aspiration is controlled inability to move tongue or absence of the tongue may prevent swallowing.
- 4.
Neck
Prior tracheostomy?
Position of tracheostomy?
Is there adequate trachea available above stoma for closure?
Imaging
Not required for this procedure
Indications
- 1.
Morbid aspiration with recurrent episodes of pneumonia not adequately managed by conservative measures
- 2.
No acceptable alternative
- 3.
Patient and family desire the procedure
Patient, family, and other stakeholders need to recognize that most patients lose their ability to speak, if able to speak preoperatively, and less than ½ of patients who undergo LTS are able to swallow postoperatively. Some, but not all, patients are able to be discharged after aspiration has been controlled.
Contraindications
- 1.
Absolute:
- a.
Family and patient refuse the procedure
- b.
Technically impossible due to very high tracheotomy—particularly if future reanastamosis is considered a possibility. Consider narrow-field laryngectomy as an alternative.
- a.
- 2.
Relative:
- a.
Duration of anticipated survival
- b.
Aspiration managed successfully with conservative strategies
- c.
High tracheotomy (will require removal of portion of cricoid ring to gain sufficient mucosa for closure)
- a.
Preoperative Preparation
- 1.
Extensive discussion with patient (if able to understand), family, and other stakeholders. Assessment of goals, recognition of the futility of additional treatment and likely progression of primary disease, likelihood that the patient may not be able to swallow or be discharged even if the procedure is performed successfully
- 2.
Optimize medical status to ensure safe surgical performance and healing. In addition to assessing the current status of anticoagulation and cardiac systems, some assessment of healing ability is necessary, especially because most patients have suffered considerable weight loss with a drop in standard measures of nutritional status. Typically this is not feasible, and surgery must be performed in less than ideal circumstances.
- 3.
Determine whether the patient is a candidate for general anesthesia.
Operative Period
Anesthesia
General: Although this procedure can be performed under local with awake sedation, general anesthesia is preferred for patient comfort, particularly when transecting the trachea, removing rings, and closing the proximal stump.
Positioning
Supine: The patient is positioned as for tracheotomy, with the neck extended over a shoulder roll. Anesthesiologist may remain at the head of the table to facilitate airway management.
Perioperative Antibiotic Prophylaxis
First-generation cephalosporin if not allergic to penicillin. Choice depends on the current status of the patient’s bacterial load and virulence. Patients undergoing LTS are often in an intensive care unit and colonized with multiple resistant organisms, so antibiotic choices must be made accordingly.
Second-generation cephalosporin—may be required if cultures indicate necessity
Clindamycin is an ideal choice if allergic to penicillin.
Monitoring
None required except routine EKG, pulse-oximetry, and capnography
Instruments and Equipment to Have Available
- 1.
Basic tracheostomy set
- 2.
Woodson elevator
- 3.
Extra endotracheal tube as well as cuffed tracheostomy tube
- 4.
Sutures to close the proximal stump and create a permanent stoma (2-0 and 3-0 Vicryl or similar)
Key Anatomic Landmarks
- 1.
Cricoid cartilage
- 2.
Sternal notch
Prerequisite Skills
- 1.
Ability to discuss “bad news” and options for palliation with patient and family
- 2.
Standard tracheotomy skill set
Operative Risks
- 1.
Intraoperative fire—similar to any tracheostomy (see Chapter 19 ). If fuel (tracheostomy or endotracheal tube) and ignition source (electrocautery) are adjacent in the presence of high levels of oxygen, fire is a distinct possibility.
- 2.
Inability to close the proximal stump due to short remaining trachea. In these situations the anterior arch of the cricoid can be removed to free sufficient mucosa for closure. If the mucosa is still insufficient, consideration must be given to performing a narrow-field laryngectomy.
Surgical Technique
- •
If a tracheotomy has previously been performed, the incision is widened laterally, and the previous tracheotomy scar and granulation tissue are excised from the skin down to the level of the trachea.
- •
Patients who have not undergone tracheotomy previously are approached as they would be for a routine tracheotomy—via a horizontal incision with dissection through subcutaneous tissue and splitting of the strap muscles to expose the trachea.
- •
Division of the thyroid isthmus (if not performed previously) is necessary to gain adequate exposure for closure of the proximal stump of the trachea.
- •
The location for the separation is identified at the site of the previous tracheotomy or at the interspace of the third or fourth tracheal ring.
- •
In older patients with an increased anteroposterior dimension of the chest, the larynx may be located more inferiorly and be resistant to retraction superiorly. In these patients the trachea may need to be divided more superiorly, at the second interspace.
- •
The higher levels of tracheal division may make the procedure easier; however, the short stump dramatically increases the difficulty of reanastomosis if attempted later.
- •
In most patients who have previously undergone tracheotomy, the proximal trachea will usually consist of only one or two rings above the level of the stoma.
- •
- •
Dissection is carried laterally around the trachea at the site of the stoma.
- •
The trachea is opened if the patient does not have an indwelling tracheostomy.
- •
An endotracheal tube is passed into the distal trachea for ventilation throughout the remainder of the procedure.
- •
The trachea is then transected, with care taken to maintain the dissection next to the wall of the trachea to avoid injury to the recurrent laryngeal nerves.
- •
The posterior wall is then transected, exposing the loose areolar tissue within the party wall, with care taken to not enter the esophagus. This is usually performed by continuing the tracheal incisions through the lateral walls bilaterally and across the posterior wall until they meet. Care should be taken to maintain this line of transection in a straight transverse plane to avoid tapering superiorly such that closure of the proximal stump becomes problematic.
- •
- •
After the trachea has been divided, it is dissected free with blunt dissection in both a superior and an inferior direction.
- •
Care should be taken to avoid extending the dissection too far into the soft tissues laterally to prevent injury to the recurrent laryngeal nerve.
- •
- •
An incision is made in the tracheal perichondrium to expose the inferior-most ring(s) in the superior stump.
- •
The ring is then dissected free using a small periosteal elevator. Care should be taken to avoid injury to the underlying perichondrium and mucosa. Removing this ring frees the internal mucoperichondrium and permits closure of the mucosa ( Fig. 21.2 ).
- •
