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Anesthesia for Tracheal Resection: A New Technique of Airway Management in a Patient with Severe Stenosis of the Midtrachea

1999; Lippincott Williams & Wilkins; Volume: 89; Issue: 5 Linguagem: Inglês

10.1213/00000539-199911000-00013

1526-7598

Spyros D. Mentzelopoulos, C. Romana, Antonis G. Hatzimichalis, Maria J. Tzoufi, E. Karamichali,

Head and Neck Surgical Oncology

We report the combined use of a Fogarty catheter (FC), a 3.5-mm fiberoptic bronchoscope (FOB), and a 6.0 endotracheal tube (ETT) to intubate the lower trachea of a patient with a primary upper- and midtracheal tumor causing a 66% stenosis of the tracheal lumen at the level of the thoracic inlet. Initially, the 6.0 ETT, with the FOB and the FC fed to its tip, was placed above the tumor and rotated 90° counterclockwise. The FOB and the FC were advanced through the stenosis, and the FC cuff was inflated just above the carina. The ETT was advanced over the FOB toward the FC cuff, and the ETT cuff was inflated below the tumor and above the FC cuff. After inspection for blood and tumor debris through the FOB's eyepiece, the FC cuff was deflated, both the FOB and FC were withdrawn, and intermittent positive pressure ventilation (IPPV) was begun. Case Report A 53-yr-old, 68-kg, 153-cm, otherwise healthy woman presented for resection of a primary tracheal tumor. She reported progressive dyspnea and hoarseness over the last three months. Auscultation of the chest revealed bilateral, monophonic inspiratory and expiratory wheeze. Computerized tomography of the neck and thorax revealed a tumor extending between the third and eighth tracheal rings and causing a 66% stenosis of the tracheal lumen at the level of the first thoracic vertebra (Fig. 1). Pulmonary function tests (Table 1) revealed a peak expiratory flow rate of 2.4 L/s (43% of predicted) and a peak inspiratory flow rate of 1.7 L/s (27% of predicted). The greater decrease in inspiratory flow than expiratory flow indicated variable inspiratory obstruction, which is characteristic of extra-thoracic tracheal lesions (1). While the patient was inspiring room air, PaO2 was 76 mm Hg, PaCO2 was 42 mm Hg, pHa was 7.42, and hemoglobin saturation was 95.3%.Figure 1: Computerized tomography of the thorax; this section is at the level of the first thoracic vertebra. A primary tracheal tumor is erupting through the left lateral and posterior tracheal walls. The internal diameter of the tracheal lumen is approximately 5 mm. The arrows point toward the intraluminal margin of the tumor.Table 1: Results of the Pulmonary Function TestsPreoperative fiberoptic bronchoscopy revealed an advanced intraluminal growth erupting through the posterior and left tracheal walls. There were areas of reddening on the mucosa of the proximal portion of the stenotic tracheal segment, and a few moderately engorged vessels were visible. However, there was no evidence of spontaneous bleeding and/or tumor-friability (e.g., areas of ulceration/necrosis). The stenotic tracheal segment was narrowed by increased inspiratory effort and widened by increased expiratory effort. Fine needle tissue sampling (2) was performed, and subsequent cytology revealed cystic adenoid carcinoma with squamous metaplasia of the overlying epithelium. The airway was evaluated as Mallampati class I (3,4), maximal head extension was 45° (5), thyromental distance was 8.2 cm (5), and sternomental distance was 14.6 cm (6). Preoperative laser photoresection, radiotherapy, and chemotherapy were not performed as a result of reasons presented in the next section of this article. After obtaining institutional approval and informed, written patient consent, we applied a new and meticulously prepared technique of airway management. The patient lay supine in a 30°-head-up position; at this position, she reported minimal discomfort while breathing spontaneously (7). After 10 min of breathing 100% O2, an inhaled induction of anesthesia with sevoflurane [tidal breathing technique with vaporizer set at 8% (8)] was performed and followed by a 1.5 mg/kg IV bolus of lidocaine. The respiratory rate decreased up to 4 breaths/min from 15 breaths/min just before the induction, but apnea did not occur. Direct laryngoscopy was performed immediately after the disappearance of the eyelid reflex. A 6.0 ETT, with an intubation FOB (insertion tube diameter = 3.5 mm, rigid distal diameter = 3.4 mm) and an FC (7F, balloon capacity = 2.5 mL) (Vermed Laboratories, Neuilly-En Thelle, France) (REF = 54178) fed to its tip, was introduced into the larynx. The FOB tip was positioned at the most proximal ETT bevel edge (Fig. 2A), and the FC was positioned at the most distal ETT bevel edge (Fig. 2A). The ETT tip was placed a few mm above the tumor's upper margin under fiberoptic visualization. Subsequent 90° counterclockwise ETT rotation and ETT cuff inflation with 15 mL of air resulted in the FC tip's pointing toward the upper orifice of the stenotic tracheal segment (Fig. 2B). The FC was introduced into the stenotic tracheal segment under fiberoptic visualization (Fig. 2C) and advanced another 10 cm. The FOB was introduced into the stenotic tracheal segment, and 1 mL of a 1:20.000 epinephrine solution and 2 mL of a 4% lidocaine solution were instilled through the FOB's instrumentation channel to reduce the risk of hemorrhage during the subsequent passage of the ETT and to anesthetize the mucosa of the stenotic tracheal segment, respectively. The FOB tip was advanced below the tumor's lower margin, and the FC tip was clearly visualized just above the carina. The FC guidewire was removed, and the FC cuff was inflated with 2.5 mL of air, resulting in isolation of both main stem bronchi (Fig. 2D). The ETT cuff was deflated, and the ETT was advanced over the FOB without encountering significant resistance. The ETT tip was advanced up to the proximal surface of the inflated FC cuff, and the ETT-cuff was inflated with 13 mL of air (Fig. 2E). After inspection for blood or tumor debris through FOB's eyepiece, the FC cuff was deflated, both the FOB and FC were removed (Fig. 2F), the ETT was rotated 90° clockwise (Fig. 2F), and IPPV was instituted.Figure 2: The technique of bypassing the midtracheal tumor and intubating the lower trachea. The hatched area corresponds to the tumor. A, The ETT (endotracheal tube), with the FOB (fiberoptic bronchoscope) and the FC (Fogarty catheter) fed to its tip, is placed above the tumor; a1 = most distal ETT bevel edge, a2 = most proximal ETT bevel edge. The ETT is rotated 90° counterclockwise. B, Sagittal section; inflation of the ETT cuff results in the FC tip's pointing toward the upper orifice of the stenotic tracheal segment. C, sagittal section; the FC is introduced into the stenotic tracheal segment. D, The FOB is advanced into the lower trachea and the FC cuff is inflated just above the carina. Correct positioning of the FC cuff is confirmed by fiberoptic bronchoscopy. E, The ETT is already advanced over the FOB and introduced into the lower trachea. The ETT cuff is inflated between the FC cuff and the lower margin of the tumor. F, The FOB and the FC are withdrawn, and the ETT is rotated 90° clockwise.The procedure of intubating the lower trachea lasted 164 s (from insertion of the laryngoscope blade into the patient's mouth to the final ETT rotation). Hemoglobin saturation (measured by pulse oximetry) was maintained >95% throughout. Readily available emergency equipment included: 1) small ETTs (size 3.5–5.5), 2) a 2.4-mm intubation FOB (PENTAX F1–7P), 3) a jet injector along with thin injector catheters (outer diameter = 1.8 mm, inner diameter = 1.2 mm, length = 55–60 cm), and 4) graduated rigid pediatric ventilating bronchoscopes (7). Furthermore, a team of experienced surgeons was standing by to perform tracheostomy if necessary. Discussion Anesthesia for tracheal resection is one of the most challenging aspects of anesthesia practice because of the unique conditions associated with narrowed airway diameter and the problem of maintaining ventilation during induction, bronchoscopy, and the period of surgical repair (7). Patients with operable tumors have either a segmental resection with primary anastomosis, a segmental resection with prosthetic reconstruction, or an insertion of a T-tube stent (9). In our case, preoperative computerized tomography and fiberoptic bronchoscopy revealed a tumor extending between the third (uppertrachea) and the eighth (midtrachea) tracheal rings and erupting through the left lateral and posterior tracheal walls. A severe stenosis (internal diameter of the tracheal lumen approximately 5 mm) was present between the fifth and seventh tracheal rings. A tissue sample was taken from the proximal orifice of the stenotic tracheal segment without hemorrhagic complications, and cytology revealed adenoid cystic carcinoma. The plan of the operation included a cervical collar incision with an upper sternal split for greater tracheal exposure (7,9) followed by segmental resection with primary anastomosis (7,9). After surgical dissection of the anterior tracheal wall, a 7.0 sterile ETT would be inserted into the distal trachea to ventilate the lungs (7,9). Preoperative laser photoresection under local anesthesia with the use of a neodymium:yttrium-aluminum-garnet laser and an FOB was ruled out, because 1) it would be difficult to control bleeding from the site of ablation/resection (10), 2) complete clearance of the airway might be difficult in a single session [in a study of 51 patients (11), an average of 1.9 treatments was required], 3) the removal of debris might be slow with the small flexible forceps (10), 4) smoke from tumor vaporization might cause coughing and patient discomfort (10), and 5) patient informed consent was lacking. Neodymium:yttrium-aluminum-garnet–laser photoresection under general anesthesia with the use of an adult rigid bronchoscope is strongly recommended for initial relief of airway obstruction caused by tracheal tumors (10,11). However, this method of treatment was not chosen, because jet ventilation would probably become necessary during the ablation/resection procedure (10,12); the initiation of jet ventilation before the achievement of some amount of widening of the stenotic tracheal segment would carry the risk of barotrauma caused by inadequate outflow pathway (≤4.5 mm) (13). Preoperative radiotherapy was ruled out, because it might cause edema and subsequent aggravation of the stenosis (10). Preoperative chemotherapy was not administered, because 1) the patient requested relief of symptoms as soon as possible, and 2) patient informed consent was lacking even for postoperative chemotherapy because of its potential toxicity (14) and variable results in patients with adenoid cystic carcinoma of the head and neck (15,16). The anesthesiology team elected to perform an inhaled induction of anesthesia with 8% sevoflurane in a tidal breathing technique. This induction technique was considered both rapid [reported achievement of adequate anesthetic depth for airway instrumentation in <2 min (8)] and safe [(reported incidence of apnea = 16% (8)]. IV lidocaine was added to blunt the reflex responses to airway instrumentation (17). The administration of neuromuscular blocking drugs was ruled out for the following reasons: 1) our objective was to preserve gas exchange for as long as possible (ideally, until the insertion of the laryngoscope blade into the mouth), in order to minimize the potential risk of oxygen-desaturation before the achievement of absolute control of the airway by successfully intubating the lower trachea, and 2) according to Young-Beyer and Wilson (7), muscle relaxants should be avoided in patients with tracheal stenosis until their airways are secured, because, in many of these patients, the anatomy of the stenosis is such that they can only ventilate when breathing spontaneously, even when anesthetized. Thus, in our patient, the administration of muscle relaxants could result in prolongation of the inadequate/no ventilation period because of the potential inability to maintain adequate gas exchange during positive-pressure ventilation via mask between the cessation of spontaneous respiration caused by neuromuscular blockade and laryngoscopy. Preoperative considerations of airway management after induction included the following alternatives: 1) Initial endotracheal intubation above the lesion followed by second intubation distal to the lesion after surgical opening of the trachea (9); the risk of inadequate ventilation caused by the severity of the stenosis would be present until the second intubation. Furthermore, the original ETT might traumatize the lesion and cause bleeding or dislodgment of tissue resulting in further airway obstruction (9). 2) Dilation of the stenosis under direct vision with graduated rigid pediatric ventilating bronchoscopes and subsequent intubation of the lower trachea with a small ETT (size 5.0–6.0); the risk of tracheal wall perforation, of bleeding, and of dislodging tumor particles would be present (7). 3) Jet ventilation via a catheter placed in the lower trachea; the risk of barotrauma, as a result of a marginal effective tracheal diameter (≤4.5 mm) for the outflow of gasses during expiration, would be present (13). 4) Intubation of the lower trachea with a 6.0 ETT as described in our report. Our new technique of airway management was already tested 50 times in a mannequin with a distensible stenosis of the midtrachea (inner diameter = 6.0 mm). The test team consisted of two experienced anesthesiologists, an assistant, and a coordinator. In the last 10 attempts, the mannequin's lower trachea was intubated in less than two minutes. However, a similar stenosis of the tracheal lumen (minimal internal diameter approximately 5 mm) was confirmed in our patient. The estimated distance (by computerized tomography) between the lower tumor-margin (eighth tracheal ring) and the carinal edge was 7–8 cm. However, the length from the proximal cuff to the distal tip of a standard 6.0 ETT is approximately 5.5 cm. Consequently, the length of the 34 functionally intact lower tracheal lumen (inner diameter = 12–15 mm) was sufficient (i.e., ≥7 cm) for the application of our technique. During preoperative fiberoptic bronchoscopy, there was no evidence of spontaneous bleeding. However, the passage of a 6.0 ETT (outer diameter = 8.2 mm) would cause considerable mechanical deformation of the tumor by compression toward a posterior and caudal direction. This deformation should be maximal at the most narrow part of the stenosis (inner diameter = 5 mm). Thus, even though there was no preoperative evidence of tumor-friability, we could not rule out the risk of traumatizing the tumor and causing dislodgment of at least fine tumor particles (e.g., cross-sectional diameter = 0.5–1 mm) and/or bleeding during the passage of the 6.0 ETT into the lower trachea. Therefore, we first isolated both mainstem bronchi by inflating the cuff of a 7F-FC just above the carina. FC cuff inflation with 2.5 mL of air would result in adequate cross-sectional diameter (approximately 16 mm) for tracheal isolation according to data obtained from the computer tomographic slices of the lower trachea. Correct placement of the FC cuff was confirmed by fiberoptic bronchoscopy. The almost simultaneous FC and FOB passage through the lesion resulted in minimal dilation of the most narrow part of the tracheal lumen (the sum of the FOB's and FC's outer diameters is 5.5–5.6 mm). The 90° counterclockwise ETT rotation facilitated the 6.0 ETT bevel's sliding on the anterior surface of the tumor. The passage of the 6.0 ETT (outer diameter = 8.2 mm) caused further dilation of 2.6 mm of the stenotic tracheal segment. However, the stenotic segment was gradually dilated and was already prepared with epinephrine and lidocaine. Furthermore, some amount of distensibility of the stenosis was already confirmed during preoperative fiberoptic bronchoscopy; an experienced endoscopist reported widening of the stenotic segment (approximately 50%) during submaximal expiratory effort from inspiratory reserve volume toward residual volume. Additionally, the inflated FC cuff eliminated any risk of unwanted aspiration (tumor debris or blood). Our patient had a functional residual capacity of 1.57 L and weighed 48.1% over ideal body weight (IBW) (18), <45.5 kg over IBW (18); IBW was calculated by a standard formula according to the patient's height (19). A 10-min preoxygenation provided us with a sufficient period of apnea tolerance [approximately 4 min (18)] to intubate the lower trachea; the procedure was completed in the mannequin in less than two minutes. After intubating the lower trachea, we were able to inspect the area between the tumor's lower margin and the FC cuff through the FOB's eyepiece. Small, dislodged tumor particles (e.g., cross-sectional diameter = 0.5–1 mm) and/or blood would be removable through the FOB's instrumentation channel (with the use of forceps or by suction) after a 3-cm withdrawal of the ETT. The ETT would then be readvanced. The removal of the dislodged tumor particles would have to be accomplished within tight time limits ( 100 removals of aspirated material in children and adults. If, according to his judgment, the dislodged debris were not easily/timely removable through the FOB's working channel, both the FOB and ETT would be replaced by a rigid bronchoscope of appropriate size. The rigid bronchoscope would be inserted into the trachea aside the FC to remove the dislodged material with the FC cuff still inflated above the carina. In that case, the rapid debris removal would compensate for the time (approximately 30 s) lost in the replacement of the FOB and the ETT by the rigid bronchoscope; an experienced endoscopist should be able to clear the airway in less than 60 seconds (i.e. within the estimated remaining time of apnea tolerance). After the removal of the dislodged material, the FC cuff would be deflated, and ventilation would be resumed through the rigid bronchoscope. However, despite our careful planning, we could not totally eliminate the (undoubtedly minimized) potential risk of oxygen-desaturation before the complete clearance of the airway from tumor debris. In that case, we would be forced to resume ventilation at the cost of minor debris-aspiration into the distal bronchial tree. In the case of the inability to intubate the lower trachea as a result of resistance to further ETT insertion, the ETT would be left in place with its tip positioned within the upper part of the stenotic tracheal segment. The size of the potentially dislodged tissue particles should permit their removal through FOB's working channel, because 1) the tumor did not seem friable, and 2) the mechanical deformation of the anterior tumor-surface by the ETT's positioning in the upper trachea would probably be minimal. Subsequently, both the FOB and FC would be withdrawn, and the following alternatives of ventilation would be considered: 1) IPPV through the 6.0 ETT; adequacy of ventilation would be judged by monitoring end-tidal CO2, peak and plateau airway pressures, expired tidal volume, end expiratory pressure and by watching lung expansion. If IPPV through the original ETT proved to be adequate, the lower trachea would be intubated with a 7.0 sterile ETT after the surgical dissection of the anterior tracheal wall between the ninth and tenth tracheal rings. 2) Withdrawal of the FOB and the original ETT and fiberoptic intubation of the lower trachea with a 4.5–5.0 ETT passed aside the FC. FOB and FC would be withdrawn after inspection for aspirated material, and IPPV would be instituted through the second ETT. 3) Emergency surgical pathway; this would be necessary in the case of inadequacy of IPPV. The estimated time to achievement of absolute control of the airway by inserting a small (4.5–5.0) tracheostomy tube into the lower trachea was approximately 2 min. However, there would be a risk of traumatizing the anterior surface of the tumor during the insertion of the tracheostomy tube into the lower trachea. 4) Jet ventilation [jet injector connected to an oxygen regulator set at 50 psi (20)] through a thin injection catheter passed into the lower trachea through the 6.0 ETT after the removal of the FOB and the FC; small tidal volumes (approximately 250–300 mL) would have to be delivered at <12 bpm to reduce the risk of air trapping and of subsequent barotrauma (13). Dimilar tidal volumes (280 mL) have been delivered by Sivarajan et al. (20) through a 1.2-mm FOB instrumentation channel, which is similar to our injector catheters in terms of inner diameter and length, while ventilating a test lung with a compliance of 50 mL/cm H2O. However, accurate measurement of the delivered tidal volumes would not be possible in our case. Jet ventilation (if chosen) would be useful only temporarily (for 1–2 min) to prevent desaturation in case of inadequacy of IPPV; tracheostomy would follow. 4) Ventilation with a rigid pediatric bronchoscope passed into the lower trachea; this would be useful only in the case of complete airway obstruction after induction and of inability to advance the FC and the FOB through the stenosis. We wish to point out that ventilation with the total laryngeal bypass device (21) (still unavailable in our institution) would be a useful alternative in the case of the inability to advance the 6.0 ETT through the stenotic tracheal segment. In conclusion, we recommend our technique for airway management in patients with severe or moderate stenosis of the midtrachea. However, a specifically trained and well coordinated anesthesiology team would be necessary to complete the procedure within reasonable time limits (<3–4 min) to prevent oxygen desaturation.