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Detection and Management of Tracheal Stenosis Following Cuffed Tube Tracheostomy
Detection and Management of Tracheal Stenosis Following Cuffed Tube Tracheostomy F. G. Pearson, M.D., and M. J. Andrews, M.D. ABSTRACT This report describes the experience with 60 instances of symptomatic posttracheostomy stricture seen at Toronto General Hospital between 1963 and 1970. Interpretation of symptoms was frequently incorrect, and diagnosis was delayed for years in some patients. Between 1967 and 1969 a prospective study of tracheal injury was undertaken. This study clarified symptomatology and revealed stricture in 32 of 153 patients, a 20% incidence of stenosis, in patients who survived treatment. Methods of treatment included endoscopic dilatation, segmental tracheal resection, staged plastic reconstruction, and permanent tracheostomy. Of 37 lesions managed by resection and end-to-end anastomosis there were 33 good results (the patient was asymptomatic), although a second resection for restenosis was necessary in 6 of these patients. There were 2 operative deaths. Operative techniques and general principles of surgical management are outlined. A laryngeal release procedure was used for mobilization in 5 patients, and our experience supports the usefulness of the maneuver. Although some mild strictures may be satisfactorily managed by endoscopic dilatation, the majority are best treated by segmental resection. Segmental defects up to 5 un. in length can be resected and successfully reconstituted by end-to-end anastomosis.
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racheal stenosis is now a well-recognized complication following cuffed tube tracheostomy and assisted ventilation. The increasing bibliography on the subject has recently been concisely reviewed in a monograph by Grillo [4].As experience with such strictures accumulates, it is possible to establish some guidelines for diagnosis and management. In this paper, the experience with 60 instances of symptomatic posttracheostomy stricture is reviewed and particular attention is directed toward recognition and surgical treatment.
Incidence A Respiratory Failure Unit was established at Toronto General Hospital in 1959 and for the past eleven years has served a densely populated From the Department of Surgery, University of Toronto, and the Division of Thoracic Surgery, Toronto General Hospital, Toronto, Ont., Canada. Supported in part by the Ontario Cancer Treatment and Research Foundation, Grant No. 221. Presented at the Seventh Annual Meeting of The Society of Thoracic Surgeons, Dallas, Tex.. Jan. 18-20, 1971. Address reprint requests to Dr. Pearson, Room 120, University Wing, Toronto General Hospital, Toronto 2, Ont., Canada.
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area of southern Ontario. There are currently about 250 admissions to the unit each year. The first stricture was identified and successfully managed by segmental resection in January, 1963. Thereafter, an increasing number of strictures was seen. In 1967 a prospective study was initiated to determine the true incidence of stricture and to clarify its pathogenesis. This study has continued to the present and has been reported in detail previously [l, 7, 81. Of patients undergoing cuffed tube tracheostomy with assisted ventilation, functionally significant strictures were identified in 32 of the 153 survivors. Prospective studies in other centers show a similar incidence of stricture [4, 61.
Detection Detection of severe stricture in which the luminal diameter is less than 5 mm. should not be difficult. At rest, patients with such strictures have stridor which is usually prominent during the inspiratory phase of respiration. The identification of mild or moderate degrees of symptomatic tracheal obstruction is much more difficult. Such strictures constitute about half those detected through the prospective study. Stridor is usually absent at rest and may be elicited only on exertion or by rapid, deep breathing. Without exception, these patients have defective exercise tolerance because of dyspnea, and this complaint is easily misinterpreted in those who previously have developed respiratory failure due to lung disease. Patients with a preexisting productive cough have difficulty in raising sputum, and the amount of sputum is usually increased. Intermittent episodes of wheezing due to transient retention of secretions may be interpreted as bronchitis or asthma. Most patients with functionally significant obstruction have a curious but characteristic brassy, “slurred” cough. Patients with moderate symptomatic obstruction are not at risk from sudden asphyxiation and may continue with their disability unrecognized for many years. In our series, 3 patients were treated for long periods (four, seven, and eight years, respectively) for chronic bronchitis or chronic obstructive lung disease before postintubation tracheal stenosis was identified as the true cause of their disability.
Treat men t Sixty instances of functionally debilitating tracheal stricture in 58 patients were encountered on the Thoracic Surgical Service at Toronto General Hospital between 1963 and 1970. During this same period, asymptomatic tracheal stenosis (luminal diameter reduced as much as 50%) was identified in many other patients, none of whom are included in this report. 360
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Forty strictures (20 stomal, 20 cuff),were treated surgically, 37 by segmental resection and primary end-to-end anastomosis and 3 by staged plastic reconstruction with cervical skin flaps. Eleven strictures (7 stomal, 4 cuff),all but 1 of which were of mild or moderate degree, were managed by endoscopic dilatation. There is no consistent evidence that severe stricture can be managed nearly as effectively by dilatation as by segmental resection and primary anastomosis [4,71. Four patients were so debilitated that only permanent tracheostomy was considered feasible, and all 4 have since died of their primary disease. There were 5 patients with untreated stricture, and it is of interest that 2 of the 5, both of whom refused treatment, died of asphyxiation due to an acute episode of retained secretions beyond the stenosis. Two others have died of unrelated disease. The fifth patient, who also refused treatment, has developed increasing exertional dyspnea and difficulty in raising sputum during a three-year follow-up. His disability is exaggerated by progressive chronic bronchitis due to continued cigarette smoking.
Results SEGMENTAL RESECTION AND PRIMARY TRACHEAL ANASTO'MOSIS
Thirty-seven strictures were managed by resection of circumferential segments between 1.5 and 5 cm. in length (Table). There were 33 good results, 1 fair result, 1 failure subsequently managed by staged plastic reconstruction, and 2 operative deaths. A good result implies complete absence of symptoms or clinical signs of upper airway obstruction and is consistent with an airway diameter greater than 50% in all radii at the level of the anastomosis. No patient was lost to follow-up, which extends between 1963 and the present. Follow-up tracheograms were done in 20 patients six months or more after operation. One patient developed moderate symptomatic restenosis (fair result) associated with a severe postoperative wound infection. A second resection was not recommended because of debility. The single failure resulted from a 3-cm. segmental resection through an inflamed trachea. An early postoperative anastomotic dehiscence occurred, with extensive loss of trachea on each side of the anastomosis. The long deRESULTS OF SEGMENTAL RESECTION
Result Good
Fair Failed Operative death Total
Stoma1 Lesions 15 1 0 1 17
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fect that resulted was reconstructed by Dr. H. C. Grill0 in Boston, using his own technique of staged replacement with bipedicled skin flaps [5]. One of the 2 operative deaths was avoidable. During the first twelve postoperative hours the patient developed laryngeal edema which was not recognized, and a hypoxic cardiac arrest occurred. Intubation or tracheostomy would have saved this patient. The other operative death occurred on the twelfth postoperative day following a second resection for restenosis of the mediastinal trachea and was due to erosion of the adjacent innominate artery. RESTENOSIS
Six of the 37 patients managed by segmental resection and primary anastomosis developed significant restenosis at the anastomosis. In 1 patient the reason for restenosis remained obscure, but the complication was explained in the other 5 as follows: In 1 patient, restenosis was due to a gross sensitivity to chromic catgut suture. In 4 patients it is presumed to have occurred because of either excessive tension at the anastomosis (3 patients) or an anastomosis of inflamed and infected tracheal ends (4patients), or both. If our assumptions about the causes of restenosis are correct, this complication should be reduced by careful preoperative assessment and adequate mobilization of the trachea at operation. All 6 patients were reoperated upon and managed by segmental resection and primary anastomosis. A good result was obtained in 5. The sixth patient (1 of the 2 operative deaths in the series) died from erosion of the adjacent innominate artery twelve days after operation. Roentgenograms obtained in 1 of the patients in whom restenosis occurred are illustrated in Figure 1. STAGED PLASTIC RECONSTRUCTION
A staged reconstruction using pedicled flaps of cervical skin was used in 3 patients in cooperation with the Department of Otolaryngology. All 3 strictures were in the subglottic area and extended above the lower border of the thyroid cartilage. Lesions at this level do not appear amenable to segmental resection and are notoriously difficult to manage effectively. In 1 of the 3, a good result was obtained and the patient is asymptomatic. The other 2 patients are much improved but still have some clinical airway obstruction. Details of operative management in these patients will be presented in a subsequent report.
Segmental Resection: Details of Operative Management The following principles are considered essential in obtaining good results with segmental resection and primary anastomosis:
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B
A
C
FIG. 1 . Roentgenograms of stoma1 stricture that restenosed after the first segmental resection. (A) T h e original stenosis. A 3-cm. segment was resected, but there was still acute inflammation in the divided tracheal ends. (B) The ensuing restenosis. Inflammatoly changes were allowed to subside, and. following a second segmental resection a good result was obtained (C).
1. Precisely determining the length and level of the stricture preoperatively 2. Having healthy tracheal ends at the anastomosis 3. Preserving tracheal circulation at the anastomosis 4. Avoiding excessive tension at the anastomosis PREOPERATIVE ASSESSMENT
Preoperative definition of the precise level and length of the stricture is critical in planning both the operative exposure and the mobilization procedures required. Adequate definition is not possible grossly at bronchoscopy since depth perception is limited by monocular vision. Anteroposterior and lateral roentgenograms of the airway provide this information, though not as clearly or accurately as do contrast tracheograms. We have used 4 to 5 ml. of Hytrastl [9],introduced under topical anesthesia, to outline the trachea from vocal cords to carina. Anteroposterior, lateral, and oblique views of the airway then provide exact definition, and no patient has experienced troublesome exaggeration of airway obstruction during the procedure. In patients with an extreme degree of stenosis (2- or 3-mm. lumen), bronchoscopic dilatation should precede the tracheogram. Cine studies during tracheography provide a dynamic evaluation of stability in the diseased area. Fishman, Dedo, *Hytrast, Fougera & Co., Inc., Hicksville, N.Y.
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and Hamilton [3] obtained similar results using powdered tantalum as a contrast material. ASSURING HEALTHY TRACHEAL ENDS
T h e condition of the trachea immediately above and below the stricture can be determined reasonably accurately at bronchoscopy. It is assumed that better primary healing will result if tracheal tissue at the anastomosis is healthy than if the tissue is softened, inflamed, and infected. During the evolution of stenosis, a gross inflammatory change may extend for some distance above and below the actual stricture. This change is recognizable endoscopically. We have had the unfortunate experience of operating upon several such patients, which entailed anastomosing a trachea that was softened and inflamed through the full thickness of its wall. One assumes that such tissue tolerates tension poorly, heals with more scar production, and predisposes to restenosis. It is present practice, therefore, to maintain an adequate airway by repeated bronchoscopic dilatation until the tracheal mucosa above and below the stricture is covered with healthy epithelium. T h e stricture itself may never epithelialize. Indwelling tracheostomy tubes predispose to airway infection and undesirable inflammation, and, whenever possible, tracheostomy tubes that have been placed through or below a stricture should be removed. OPERATIVE EXPOSURE
T h e operative exposures required for segmental resection are illustrated in Figure 2. T h e airway between the hyoid bone and the midmediastinal trachea is easily accessible through a generous collar incision. Early in our
. proximal 73 trachea 2. laryngeal release
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FIG. 2. T h e operative exposures required for segmental tracheal resection, indicating the area exposed by various incisions and the mobilization procedures possible through each.
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experience we added median sternotomy to the collar incision for stricture in the upper mediastinal trachea but have since found that this is unnecessary unless the patient has a very short, thick neck or a rigid trachea. With the neck extended, a bolster between the shoulders, and a traction suture placed in the anterior trachea below the stricture, it is almost always possible to elevate a long segment of mediastinal trachea into the operative field afforded through a collar incision. The addition of median sternotomy to the collar incision provides access to the entire trachea, and extension of the sternotomy through the fifth right intercostal space as far as the posterior axillary line allows mobilization of the hilum of the right lung. If the stricture is located in the distal 4 or 5 cm. of the mediastinal trachea, adequate exposure can be obtained with a right posterolateral thoracotomy. Short strictures at this low level are uncommon, and the incision has been used in only 2 patients in our series. PRESERVING TRACHEAL CIRCULATION
The tracheal circulation is illustrated in Figure 3. The most robust contributions to the tracheal blood supply originate at the upper and lower ends. Branches from the inferior thyroid and superior intercostal arteries descend from above, and the bronchial arterial vessels ascend from below. Between these levels, much finer vessels which originate from intercostal arteries reach the posterolateral aspects of the trachea. A few fine vessels extend between the esophagus and the membranous trachea. Fine anastomoses are present over the surface of the trachea between all these vessels, which penetrate between the cartilage rings to feed an extremely rich submucosal plexus. This plexus is easily identified at operation, and for successful anastomosis, bright red bleeding should occur in this area at the transected tracheal ends. FIG. 3. The tracheal circulation, showing the inferior thyroid, bronchial, lateral tracheal, and esophageal arteries.
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T h e supply from the inferior thyroid and superior intercostal arteries is not at risk in any of the resections required. At the distal end, however, care is taken to avoid division of the bronchial arterial vessels if mobilization of the right hilum is required. Throughout its length, it is possible to clear the entire anterior surface of the trachea and the anterior half of the lateral aspect without interrupting circulation to any appreciable extent. Circumferential mobilization of the trachea leaves a segment which depends entirely upon the submucosal plexus for survival, and such mobilization should be restricted to lengths not exceeding 1 cm. above or below the divided tracheal ends. Grill0 [5] frees the esophagus from the central aspect of the membranous trachea by blunt dissection to obtain additional mobilization, but we have not yet used this maneuver. Circumferential mobilization of the stricture and adjacent trachea is achieved by sharp dissection in the plane immediately adjacent to the tracheal wall. This approach avoids injury to the recurrent laryngeal nerves at the tracheoesophageal angle. No attempt is made to identify these nerves, which may lie in scar at the level of the stenosis. Recurrent nerve palsy has not occurred in any of the 37 patients in this series who were treated by segmental resection. T h e anastomosis is secured with a single layer of interrupted 2-0 or 3-0 chromic catgut sutures (Fig. 4). Sutures are placed precisely, obtaining a generous bite through the full thickness of the tracheal wall, and are spaced at 0.4- to 0.5-cm. intervals. Care is taken to achieve circumferential mucosal apposition with even tension at each suture. This technique should produce the least interference with circulation at the tracheal ends. AVOIDING EXCESSIVE TENSION
Most postintubation strictures are short and require excision of a tracheal segment less than 3 cm. in length. With a few exceptions, defects of this magnitude can be successfully closed with minimal mobilization of the trachea, by freeing the anterolateral aspect of the trachea from stricture to distal end, and performing circumferential mobilization of a 1-cm. segment FIG. 4 . T h e technique of primary tracheal anastomosis. Znlerrupted 2-0 or 3 0 chromic catgut suture is used, with knots tied on the outside.
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at each cut end. In elderly patients, however, tracheal elasticity is diminished, and excision of even these short defects is associated with dangerous levels of tension when the tracheal ends are approximated. When segments longer than 3 cm. are resected, it is almost certain that additional mobilization will be required to avoid undue tension. Unfortunately, there is not yet a practical method to quantitate tension at the anastomosis, and this evaluation must be learned through experience. Tension at the anastomosis may be reduced by two additional techniques: The laryngeal release operation described by Dedo and Fishman [2] permits resection of an additional 2 cm. of trachea. Mobilization of the right pulmonary hilum permits resection of a further 2 cm. It is therefore possible to resect circumferential segments up to 7 cm. in length and approximate the divided tracheal ends without undue tension or critical interruption of the tracheal blood supply. In this series the most extensive segmental resection was 5 cm. in length, though we have achieved successful primary anastomosis following excision for tumor of a 7-cm. segment. LARYNGEAL RELEASE
During the past two years we have used laryngeal release in selected patients and have found it an extremely useful technique for reducing anastomotic tension. The operative technique is illustrated in Figure 5. Each sternohyoid muscle is retracted laterally, and the underlying soft tissues between the hyoid and thyroid cartilages are then divided by sharp dissection until the pharyngeal submucosa is exposed anteriorly in the interval between the superior cornua of the thyroid cartilage. This requires division of each thyrohyoid muscle, the thyrohyoid membrane, and the central ligamentous thickening of the membrane. The superior cornua of the thyroid cartilage are amputated, taking care to avoid injuring the superior laryngeal nerves and their accompanying vessels. In the anterior plane, this procedure drops the thyroid cartilage and trachea about 2 cm. below the previous level (Fig. 6, top). Less descent is FIG. 5. The laryngeal release procedure used to obtain additional tracheal mobilization. (sup. cornu = superior cornua; sup. laryngeal a.n.v. = superior laryngeal artery, nerue, vessels.)
PEARSON AND ANDREWS Normal
n
laryngeal Release
2cms.
FZG. 6. Normal anatomy an-
teroposteriorly and laterally, compared with changes following laryngeal release. T h e greatest mobilization is achieved anteriorly, which is usually the site of greatest anastomotic tension.
achieved posteriorly (Fig. 6, bottom), but less mobilization is required here since normally the trachea angulates slightly posteriorly below the level of the seventh cervical vertebra. T h e greatest anastomotic tension is nearly always created anteriorly. We have added a laryngeal release procedure in 5 patients. I n 4 patients, segments between 3 and 5 cm. in length were resected, and in 1 elderly patient a 3-cm. segment was excised in a rigid, inelastic trachea. A good result was obtained in each instance. Laryngeal release results in transient loss of coordination of swallowing mechanisms, and swallowed solids or liquids may be aspirated into the tracheobronchial tree. This disability may persist up to two months following operation and was prominent in 3 of our 5 patients. In all 5, however, the defect resolved completely and without serious complication. We have followed the suggestions recommended by Dedo and Fishman [Z] for the postoperative management of this problem. MOBILIZATION OF RIGHT PULMONARY HILUM
Circumferential intrapericardial mobilization of the hilum of the right lung is well described by Grillo [4].This procedure permits resection of an additional 2 cm. of trachea and requires exposure through a posterolateral thoracotomy or through lateral extension of a median sternotomy in the fifth right intercostal space. T h e technique was used in only 2 patients in the present series and is more frequently required for more extensive resections of the mediastinal trachea in patients with neoplasm. POSTOPERATIVE MANAGEMENT
Patients were extubated as soon as they were sufficientlyrecovered from anesthesia. Postoperative tracheostomy is usually unnecessary and should be avoided if possible, to obviate associated airway infection or pressure at the 368
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FIG. 7. Technique of maintaining cervical flexion for ten to fourteen days following tracheal resection.
anastomosis. Three patients developed glottic or supraglottic edema during the first 24 hours after operation (2 following laryngeal release, 1 due to hematoma in the cervical incision). All 3 were effectively managed by a short period (less than 24 hours) of orotracheal intubation with an uncuffed tube and the concomitant administration of steroids and inhalation of a nebulized vasoconstrictor. Cervical flexion undoubtedly reduces tension at the anastomosis, and it is maintained for at least ten days after operation. During the past four years, postoperative neck flexion has been very effectively maintained by a stout silk suture tethering the skin of the chin to the skin of the chest (Fig. 7). This apparently barbaric maneuver is surprisingly well tolerated by the patient and is completely dependable in maintaining flexion at all times.
Case Report One case history illustrates many of the principles of management described. A 45-year-old woman was transferred from another hospital four months following recognition of a stricture in the mediastinal trachea. Prior to her admission to Toronto General Hospital, the stricture had been managed by repeated bronchoscopic dilatations, silver nitrate cauterization, and prolonged stenting with a long metal tracheostomy tube introduced through a cervical stoma. At the time of admission to Toronto General Hospital, bronchoscopy revealed acute mucosal inflammation and ulceration of the entire trachea
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between the cervical stoma and the carina. A long stricture was identified in the mediastinal trachea which extended to within 1 cm. of the carina. T h e stricture was dilated with a No. 7 bronchoscope, and a tracheogram was obtained the day after admission (Fig. 8A). T h e damaged segment was 5 cm. in length, but the entire trachea was markedly softened from stoma to carina and collapsed on coughing, as shown in Figure 8A. T h e tracheostomy tube was removed and the cervical stoma allowed to close, treatment with appropriate antibiotics was instituted, and airway patency was maintained by frequent bronchoscopic dilatations. During the ensuing eight weeks, inflammatory changes in the tracheal mucosa above and below the damaged segment gradually subsided. A repeat tracheogram showed a marked decrease in tracheal softening and collapse except in the irreparably damaged 5-cm. segment, which was now precisely delineated. Figure 8B shows this second preoperative tracheogram, and the length of the excised damaged segment is shown by comparison with the postoperative tracheogram, Figure 8C. At operation, exposure was obtained with a collar incision and median
A
B
C
FIG. 8. Interval tracheograms illustrating the management of a 5-cm. stricture resected f r o m the mediastinal trachea. (A) Film obtained o n the second hospital day. T h e markedly softened trachea is seen t o collapse o n coughing. (B) Tracheogram obtained eight weeks later, showing decreased tracheal softening and collapse following closure of the tracheostomy and a course of antibiotic treatment t o reduce mucosal inflammation. ( C ) Postoperative tracheogram following excision of the diseased segment (upper arrow: vocal cords; lower arrow: carina).
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FIG. 9. A good result is seen in roentgenograms obtained two months postoperatively.
sternotomy. A 5-cm. segment of mediastinal trachea was excised and additional mobilization obtained by laryngeal release. Although we were prepared to extend the incision and mobilize the right pulmonary hilum, this proved unnecessary, and primary anastomosis with satisfactory tension was possible. Three hours after operation the patient developed severe supraglottic edema associated with a hematoma in the cervical incision. An airway was established by intubation with a small, uncuffed orotracheal tube, the hematoma was evacuated, and a small bleeding artery was ligated. Within a further six hours the patient was extubated, and no further airway obstruction occurred. Thereafter, the patient had difficulty with uncoordinated swallowing and aspiration which did not resolve completely until six weeks after operation. A good result was obtained, and the patient was free from clinical evidence of airway obstruction at last follow-up, thirteen months after resection. Oblique and anteroposterior projections of a tracheogram obtained two months after operation are illustrated in Figure 9.
References 1. Andrews, M. J., and Pearson, F. G. The incidence and pathogenesis of tracheal injury following cuffed tube tracheostomy with assisted ventilation: An analysis of a two year prospective study. Ann. Surg. 173:249, 1971. 2. Dedo, H. H., and Fishman, N. H. Laryngeal release and sleeve resection for tracheal stenosis. Ann. Otol. 78285, 1969. 3. Fishman, N. H., Dedo, H. H., Hamilton, W. K., Hinchcliffe, W. A., and Roe, B. B. Postintubation tracheal stenosis. Ann. Thorac. Surg. 8:47, 1969. 4. Grillo, H. C. Surgical approaches to the trachea. Surg. Gynec. Obstet. 129: 347, 1969. VOL. 12, NO.
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5. Grillo, H. C. Surgery of the trachea. Curr. Probl. Surg., (July) 1970. 6. Lindholm, C. E. Prolonged endotracheal intubation. Acta Anaesth. Scand. Suppl. 33, 1969. 7. Pearson, F. G., Goldberg, M., and DaSilva, A. J. A prospective study of tracheal injury complicating tracheostomy with a cuffed tube. Ann. Otol. 77:867, 1968. 8. Pearson, F. G., Goldberg, M., and DaSilva, A. J. Tracheal stenosis complicating tracheostomy with cuffed tubes. Arch. Surg. (Chicago) 97:380, 1968. 9. Webb, W. R., and Fitts, C. T. Evaluation of Hytrast as bronchographic medium. Amer. Surg. 29:491, 1963.
Discussion DR. KEN L. HARDY (Oakland, Calif.): Dr. Pearson’s extensive experience has again contributed to our knowledge about the treatment of a serious iatrogenic complication of assisted respiration. Even with such a thorough type of prospective analysis to detect early stricture, a 20% incidence seems surprisingly high. Equally interesting is the report of more stomal than cuff lesions. We have not had a stomal stricture in more than six years and attribute this to the following technique: A circular plug of anterior tracheal wall at the third ring is excised in an unhurried manner over an endotracheal tube. T h e round opening is made large enough to accommodate easily a tracheostomy tube of the selected diameter, which is then gently inserted over a lubricated, smoothly beveled obturator to prevent damage to the posterior mucosa as the tube is withdrawn. Linear or cruciate incisions which require a forceable thrust for introduction of the tube may cause wall fracture, mucosal tears, and one or more inwardly bent flaps, predisposing to repair by scar at the stoma. A migratory cuff or loose inflation line can cause further stomal irritation. I would like to ask Dr. Pearson what types of cuffed tubes were used in his patients. Were they passed over an obturator, and how were the stomas created? Our 7 strictures were all at the cuff level and occurred earlier than two and a half years ago. Five of these were detected early and were cured by dilatations. Two, diagnosed late, required segmental resection. With this experience we began concentrating on prevention of cuff stricture, and we have not had any in the past thirty months. We believe that this is due mainly to two factors: (1) intensive instruction to nurses and therapists not to exceed minimal occluding volume (MOV) when inflating the cuff; MOV is that volume of air required to cause seal at 30 cm. H,O; (2) the use of a tube introduced to this society last year which has an integral balloon that inflates to a symmetrical sausage contour. This allows MOV to be achieved at lower actual tracheal pressures than when an eccentric circular balloon is used. This tube with its pivotal neck flange rides free in the tracheal lumen, avoiding tip impingement and mucosal ulceration, and its
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obturator allows for gentle passage. Shiley Laboratories have manufactured an identical tube with a larger, 300% volume balloon of the same contour. This tube is presently being evaluated. DR. NICHOLAS J. DEMOS(Jersey City, N.J.): Since prevention is preferable to treatment, I would like to present to you a new and exciting idea in tracheostomy cuffs. The cuff is very easily fashioned from sterilized foam rubber ordinarily used for the prevention of decubitus ulcers. After the paper is peeled off, the foam rubber is glued onto any type of tracheostomy cannula and secured with a silk ligature. For easy insertion of the tube, the paper, following removal, is wrapped around the cuff to reduce its volume. When the cuff is about three-quarters through the tracheal opening, the paper is easily removed and the remainder of the tube is inserted. After the cuff had been in use in a group of dogs for up to three days, only slight inflammation was present on the mucaa. Measurement of cuff pressure against the tracheal wall revealed a maximum pressure of only 28 cm. HzO, which compares very favorably with pressures of up to 250 mm. Hg exerted by the usual inflatable cuffs. Having obtained permission from our appropriate committee, we are testing this new cuff on our patients with equal success.
DR. MILTONV. DAVIS(Dallas, Tex.): I join with the two previous discussants in referring to the importance of prevention, and I think that little more need be said about that. The reason I requested time to discuss this fine paper is because I think that a word should be said about the indwelling stent. The stent lies just below the vocal cords and just above the carina. Originally we anchored these stents with wire and with nonabsorbable synthetic sutures. More recently, we have simply put them in and let them lie below the cords, and they stay quite well in that location with or without a tracheostomy tube. The usual methods of dilation are not nearly as effective as the indwelling stent. Later, if operation becomes necessary, the indwelling stent provides the condition set down by Dr. Pearson and his associates of allowing the inflammation to recede to its maximum before an operation is performed. We started putting in stents for that purpose, and we were able to effect what amounted to a surgical cure without ever doing the operation. DR. PEARSON: I thank all three discussants for their comments. In answer to Dr. Hardy's questions: We have used two types of tubes during the period of the prospective study, the Portex tube and the James red rubber tube. There was no difference in the incidence of stricture following use of either of these tubes. Recently we have used the Portex tube with a hyperinflated cuff, as described by Dr. Bendixen in Boston. We have seen VOL. 12, NO.
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2 strictures following the use of this modification, but we do not yet have enough data to know if the incidence of stricture is actually less. I agree with Dr. Hardy that the incidence of stoma1 stenosis observed in our series is exceptionally high. I think one of the main reasons for this is that the prospective study has resulted in detection of lesions at the stoma which otherwise might easily have been overlooked since the obstruction is not severe. I believe that some stomal narrowing will result regardless of the type of tracheostomy tube used or the type of incision employed. One inevitably loses some tracheal cartilage anteriorly, and in patients who are hypoperfused or on steroids we have found a still more extensive loss of cartilage at the stomal site. Again, I would emphasize that the stomal stricture most commonly produces a mild or moderate degree of obstruction. Of the 60 strictures reported today, 37 were at the stomal level but only 18 were sufficiently severe to require resection. Twenty of the 26 lesions at the cuff level required resection. I anticipate that in the future we will use tubes of modified design which cause less damage than those used in the past, and I think Dr. Hardy’s modification is definitely a step in that direction. Ultimately, I believe we may find a mechanism other than the inflatable cuff for airway control during assisted ventilation. Dr. Demos has suggested an ingenious and novel method for securing airway occlusion during assisted ventilation. Time will tell how effective this modification will be. At the moment, I would be concerned that this technique will not permit precise control of lateral tracheal wall pressures. Dr. Davis makes a good point about the use of an indwelling stent as definitive management for tracheal stenosis. A number of patients have been successfully treated in this way and reported in the literature. Not all strictures, however, can be reliably managed by this method. If full-thickness loss of tracheal wall has occurred, stenting techniques are unsuccessful in our experience. Although our otolaryngologists have successfully treated a few patients in this way, in others, restenosis developed after the stent was removed even though it had been left in place for periods up to six months. Resection was ultimately required in these patients.
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racheal stenosis is now a well-recognized complication following cuffed tube tracheostomy and assisted ventilation. The increasing bibliography on the subject has recently been concisely reviewed in a monograph by Grillo [4].As experience with such strictures accumulates, it is possible to establish some guidelines for diagnosis and management. In this paper, the experience with 60 instances of symptomatic posttracheostomy stricture is reviewed and particular attention is directed toward recognition and surgical treatment.
Incidence A Respiratory Failure Unit was established at Toronto General Hospital in 1959 and for the past eleven years has served a densely populated From the Department of Surgery, University of Toronto, and the Division of Thoracic Surgery, Toronto General Hospital, Toronto, Ont., Canada. Supported in part by the Ontario Cancer Treatment and Research Foundation, Grant No. 221. Presented at the Seventh Annual Meeting of The Society of Thoracic Surgeons, Dallas, Tex.. Jan. 18-20, 1971. Address reprint requests to Dr. Pearson, Room 120, University Wing, Toronto General Hospital, Toronto 2, Ont., Canada.
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area of southern Ontario. There are currently about 250 admissions to the unit each year. The first stricture was identified and successfully managed by segmental resection in January, 1963. Thereafter, an increasing number of strictures was seen. In 1967 a prospective study was initiated to determine the true incidence of stricture and to clarify its pathogenesis. This study has continued to the present and has been reported in detail previously [l, 7, 81. Of patients undergoing cuffed tube tracheostomy with assisted ventilation, functionally significant strictures were identified in 32 of the 153 survivors. Prospective studies in other centers show a similar incidence of stricture [4, 61.
Detection Detection of severe stricture in which the luminal diameter is less than 5 mm. should not be difficult. At rest, patients with such strictures have stridor which is usually prominent during the inspiratory phase of respiration. The identification of mild or moderate degrees of symptomatic tracheal obstruction is much more difficult. Such strictures constitute about half those detected through the prospective study. Stridor is usually absent at rest and may be elicited only on exertion or by rapid, deep breathing. Without exception, these patients have defective exercise tolerance because of dyspnea, and this complaint is easily misinterpreted in those who previously have developed respiratory failure due to lung disease. Patients with a preexisting productive cough have difficulty in raising sputum, and the amount of sputum is usually increased. Intermittent episodes of wheezing due to transient retention of secretions may be interpreted as bronchitis or asthma. Most patients with functionally significant obstruction have a curious but characteristic brassy, “slurred” cough. Patients with moderate symptomatic obstruction are not at risk from sudden asphyxiation and may continue with their disability unrecognized for many years. In our series, 3 patients were treated for long periods (four, seven, and eight years, respectively) for chronic bronchitis or chronic obstructive lung disease before postintubation tracheal stenosis was identified as the true cause of their disability.
Treat men t Sixty instances of functionally debilitating tracheal stricture in 58 patients were encountered on the Thoracic Surgical Service at Toronto General Hospital between 1963 and 1970. During this same period, asymptomatic tracheal stenosis (luminal diameter reduced as much as 50%) was identified in many other patients, none of whom are included in this report. 360
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Forty strictures (20 stomal, 20 cuff),were treated surgically, 37 by segmental resection and primary end-to-end anastomosis and 3 by staged plastic reconstruction with cervical skin flaps. Eleven strictures (7 stomal, 4 cuff),all but 1 of which were of mild or moderate degree, were managed by endoscopic dilatation. There is no consistent evidence that severe stricture can be managed nearly as effectively by dilatation as by segmental resection and primary anastomosis [4,71. Four patients were so debilitated that only permanent tracheostomy was considered feasible, and all 4 have since died of their primary disease. There were 5 patients with untreated stricture, and it is of interest that 2 of the 5, both of whom refused treatment, died of asphyxiation due to an acute episode of retained secretions beyond the stenosis. Two others have died of unrelated disease. The fifth patient, who also refused treatment, has developed increasing exertional dyspnea and difficulty in raising sputum during a three-year follow-up. His disability is exaggerated by progressive chronic bronchitis due to continued cigarette smoking.
Results SEGMENTAL RESECTION AND PRIMARY TRACHEAL ANASTO'MOSIS
Thirty-seven strictures were managed by resection of circumferential segments between 1.5 and 5 cm. in length (Table). There were 33 good results, 1 fair result, 1 failure subsequently managed by staged plastic reconstruction, and 2 operative deaths. A good result implies complete absence of symptoms or clinical signs of upper airway obstruction and is consistent with an airway diameter greater than 50% in all radii at the level of the anastomosis. No patient was lost to follow-up, which extends between 1963 and the present. Follow-up tracheograms were done in 20 patients six months or more after operation. One patient developed moderate symptomatic restenosis (fair result) associated with a severe postoperative wound infection. A second resection was not recommended because of debility. The single failure resulted from a 3-cm. segmental resection through an inflamed trachea. An early postoperative anastomotic dehiscence occurred, with extensive loss of trachea on each side of the anastomosis. The long deRESULTS OF SEGMENTAL RESECTION
Result Good
Fair Failed Operative death Total
Stoma1 Lesions 15 1 0 1 17
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fect that resulted was reconstructed by Dr. H. C. Grill0 in Boston, using his own technique of staged replacement with bipedicled skin flaps [5]. One of the 2 operative deaths was avoidable. During the first twelve postoperative hours the patient developed laryngeal edema which was not recognized, and a hypoxic cardiac arrest occurred. Intubation or tracheostomy would have saved this patient. The other operative death occurred on the twelfth postoperative day following a second resection for restenosis of the mediastinal trachea and was due to erosion of the adjacent innominate artery. RESTENOSIS
Six of the 37 patients managed by segmental resection and primary anastomosis developed significant restenosis at the anastomosis. In 1 patient the reason for restenosis remained obscure, but the complication was explained in the other 5 as follows: In 1 patient, restenosis was due to a gross sensitivity to chromic catgut suture. In 4 patients it is presumed to have occurred because of either excessive tension at the anastomosis (3 patients) or an anastomosis of inflamed and infected tracheal ends (4patients), or both. If our assumptions about the causes of restenosis are correct, this complication should be reduced by careful preoperative assessment and adequate mobilization of the trachea at operation. All 6 patients were reoperated upon and managed by segmental resection and primary anastomosis. A good result was obtained in 5. The sixth patient (1 of the 2 operative deaths in the series) died from erosion of the adjacent innominate artery twelve days after operation. Roentgenograms obtained in 1 of the patients in whom restenosis occurred are illustrated in Figure 1. STAGED PLASTIC RECONSTRUCTION
A staged reconstruction using pedicled flaps of cervical skin was used in 3 patients in cooperation with the Department of Otolaryngology. All 3 strictures were in the subglottic area and extended above the lower border of the thyroid cartilage. Lesions at this level do not appear amenable to segmental resection and are notoriously difficult to manage effectively. In 1 of the 3, a good result was obtained and the patient is asymptomatic. The other 2 patients are much improved but still have some clinical airway obstruction. Details of operative management in these patients will be presented in a subsequent report.
Segmental Resection: Details of Operative Management The following principles are considered essential in obtaining good results with segmental resection and primary anastomosis:
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B
A
C
FIG. 1 . Roentgenograms of stoma1 stricture that restenosed after the first segmental resection. (A) T h e original stenosis. A 3-cm. segment was resected, but there was still acute inflammation in the divided tracheal ends. (B) The ensuing restenosis. Inflammatoly changes were allowed to subside, and. following a second segmental resection a good result was obtained (C).
1. Precisely determining the length and level of the stricture preoperatively 2. Having healthy tracheal ends at the anastomosis 3. Preserving tracheal circulation at the anastomosis 4. Avoiding excessive tension at the anastomosis PREOPERATIVE ASSESSMENT
Preoperative definition of the precise level and length of the stricture is critical in planning both the operative exposure and the mobilization procedures required. Adequate definition is not possible grossly at bronchoscopy since depth perception is limited by monocular vision. Anteroposterior and lateral roentgenograms of the airway provide this information, though not as clearly or accurately as do contrast tracheograms. We have used 4 to 5 ml. of Hytrastl [9],introduced under topical anesthesia, to outline the trachea from vocal cords to carina. Anteroposterior, lateral, and oblique views of the airway then provide exact definition, and no patient has experienced troublesome exaggeration of airway obstruction during the procedure. In patients with an extreme degree of stenosis (2- or 3-mm. lumen), bronchoscopic dilatation should precede the tracheogram. Cine studies during tracheography provide a dynamic evaluation of stability in the diseased area. Fishman, Dedo, *Hytrast, Fougera & Co., Inc., Hicksville, N.Y.
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and Hamilton [3] obtained similar results using powdered tantalum as a contrast material. ASSURING HEALTHY TRACHEAL ENDS
T h e condition of the trachea immediately above and below the stricture can be determined reasonably accurately at bronchoscopy. It is assumed that better primary healing will result if tracheal tissue at the anastomosis is healthy than if the tissue is softened, inflamed, and infected. During the evolution of stenosis, a gross inflammatory change may extend for some distance above and below the actual stricture. This change is recognizable endoscopically. We have had the unfortunate experience of operating upon several such patients, which entailed anastomosing a trachea that was softened and inflamed through the full thickness of its wall. One assumes that such tissue tolerates tension poorly, heals with more scar production, and predisposes to restenosis. It is present practice, therefore, to maintain an adequate airway by repeated bronchoscopic dilatation until the tracheal mucosa above and below the stricture is covered with healthy epithelium. T h e stricture itself may never epithelialize. Indwelling tracheostomy tubes predispose to airway infection and undesirable inflammation, and, whenever possible, tracheostomy tubes that have been placed through or below a stricture should be removed. OPERATIVE EXPOSURE
T h e operative exposures required for segmental resection are illustrated in Figure 2. T h e airway between the hyoid bone and the midmediastinal trachea is easily accessible through a generous collar incision. Early in our
. proximal 73 trachea 2. laryngeal release
mob i Iiza t io n rig hi hi Ium
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FIG. 2. T h e operative exposures required for segmental tracheal resection, indicating the area exposed by various incisions and the mobilization procedures possible through each.
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experience we added median sternotomy to the collar incision for stricture in the upper mediastinal trachea but have since found that this is unnecessary unless the patient has a very short, thick neck or a rigid trachea. With the neck extended, a bolster between the shoulders, and a traction suture placed in the anterior trachea below the stricture, it is almost always possible to elevate a long segment of mediastinal trachea into the operative field afforded through a collar incision. The addition of median sternotomy to the collar incision provides access to the entire trachea, and extension of the sternotomy through the fifth right intercostal space as far as the posterior axillary line allows mobilization of the hilum of the right lung. If the stricture is located in the distal 4 or 5 cm. of the mediastinal trachea, adequate exposure can be obtained with a right posterolateral thoracotomy. Short strictures at this low level are uncommon, and the incision has been used in only 2 patients in our series. PRESERVING TRACHEAL CIRCULATION
The tracheal circulation is illustrated in Figure 3. The most robust contributions to the tracheal blood supply originate at the upper and lower ends. Branches from the inferior thyroid and superior intercostal arteries descend from above, and the bronchial arterial vessels ascend from below. Between these levels, much finer vessels which originate from intercostal arteries reach the posterolateral aspects of the trachea. A few fine vessels extend between the esophagus and the membranous trachea. Fine anastomoses are present over the surface of the trachea between all these vessels, which penetrate between the cartilage rings to feed an extremely rich submucosal plexus. This plexus is easily identified at operation, and for successful anastomosis, bright red bleeding should occur in this area at the transected tracheal ends. FIG. 3. The tracheal circulation, showing the inferior thyroid, bronchial, lateral tracheal, and esophageal arteries.
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T h e supply from the inferior thyroid and superior intercostal arteries is not at risk in any of the resections required. At the distal end, however, care is taken to avoid division of the bronchial arterial vessels if mobilization of the right hilum is required. Throughout its length, it is possible to clear the entire anterior surface of the trachea and the anterior half of the lateral aspect without interrupting circulation to any appreciable extent. Circumferential mobilization of the trachea leaves a segment which depends entirely upon the submucosal plexus for survival, and such mobilization should be restricted to lengths not exceeding 1 cm. above or below the divided tracheal ends. Grill0 [5] frees the esophagus from the central aspect of the membranous trachea by blunt dissection to obtain additional mobilization, but we have not yet used this maneuver. Circumferential mobilization of the stricture and adjacent trachea is achieved by sharp dissection in the plane immediately adjacent to the tracheal wall. This approach avoids injury to the recurrent laryngeal nerves at the tracheoesophageal angle. No attempt is made to identify these nerves, which may lie in scar at the level of the stenosis. Recurrent nerve palsy has not occurred in any of the 37 patients in this series who were treated by segmental resection. T h e anastomosis is secured with a single layer of interrupted 2-0 or 3-0 chromic catgut sutures (Fig. 4). Sutures are placed precisely, obtaining a generous bite through the full thickness of the tracheal wall, and are spaced at 0.4- to 0.5-cm. intervals. Care is taken to achieve circumferential mucosal apposition with even tension at each suture. This technique should produce the least interference with circulation at the tracheal ends. AVOIDING EXCESSIVE TENSION
Most postintubation strictures are short and require excision of a tracheal segment less than 3 cm. in length. With a few exceptions, defects of this magnitude can be successfully closed with minimal mobilization of the trachea, by freeing the anterolateral aspect of the trachea from stricture to distal end, and performing circumferential mobilization of a 1-cm. segment FIG. 4 . T h e technique of primary tracheal anastomosis. Znlerrupted 2-0 or 3 0 chromic catgut suture is used, with knots tied on the outside.
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at each cut end. In elderly patients, however, tracheal elasticity is diminished, and excision of even these short defects is associated with dangerous levels of tension when the tracheal ends are approximated. When segments longer than 3 cm. are resected, it is almost certain that additional mobilization will be required to avoid undue tension. Unfortunately, there is not yet a practical method to quantitate tension at the anastomosis, and this evaluation must be learned through experience. Tension at the anastomosis may be reduced by two additional techniques: The laryngeal release operation described by Dedo and Fishman [2] permits resection of an additional 2 cm. of trachea. Mobilization of the right pulmonary hilum permits resection of a further 2 cm. It is therefore possible to resect circumferential segments up to 7 cm. in length and approximate the divided tracheal ends without undue tension or critical interruption of the tracheal blood supply. In this series the most extensive segmental resection was 5 cm. in length, though we have achieved successful primary anastomosis following excision for tumor of a 7-cm. segment. LARYNGEAL RELEASE
During the past two years we have used laryngeal release in selected patients and have found it an extremely useful technique for reducing anastomotic tension. The operative technique is illustrated in Figure 5. Each sternohyoid muscle is retracted laterally, and the underlying soft tissues between the hyoid and thyroid cartilages are then divided by sharp dissection until the pharyngeal submucosa is exposed anteriorly in the interval between the superior cornua of the thyroid cartilage. This requires division of each thyrohyoid muscle, the thyrohyoid membrane, and the central ligamentous thickening of the membrane. The superior cornua of the thyroid cartilage are amputated, taking care to avoid injuring the superior laryngeal nerves and their accompanying vessels. In the anterior plane, this procedure drops the thyroid cartilage and trachea about 2 cm. below the previous level (Fig. 6, top). Less descent is FIG. 5. The laryngeal release procedure used to obtain additional tracheal mobilization. (sup. cornu = superior cornua; sup. laryngeal a.n.v. = superior laryngeal artery, nerue, vessels.)
PEARSON AND ANDREWS Normal
n
laryngeal Release
2cms.
FZG. 6. Normal anatomy an-
teroposteriorly and laterally, compared with changes following laryngeal release. T h e greatest mobilization is achieved anteriorly, which is usually the site of greatest anastomotic tension.
achieved posteriorly (Fig. 6, bottom), but less mobilization is required here since normally the trachea angulates slightly posteriorly below the level of the seventh cervical vertebra. T h e greatest anastomotic tension is nearly always created anteriorly. We have added a laryngeal release procedure in 5 patients. I n 4 patients, segments between 3 and 5 cm. in length were resected, and in 1 elderly patient a 3-cm. segment was excised in a rigid, inelastic trachea. A good result was obtained in each instance. Laryngeal release results in transient loss of coordination of swallowing mechanisms, and swallowed solids or liquids may be aspirated into the tracheobronchial tree. This disability may persist up to two months following operation and was prominent in 3 of our 5 patients. In all 5, however, the defect resolved completely and without serious complication. We have followed the suggestions recommended by Dedo and Fishman [Z] for the postoperative management of this problem. MOBILIZATION OF RIGHT PULMONARY HILUM
Circumferential intrapericardial mobilization of the hilum of the right lung is well described by Grillo [4].This procedure permits resection of an additional 2 cm. of trachea and requires exposure through a posterolateral thoracotomy or through lateral extension of a median sternotomy in the fifth right intercostal space. T h e technique was used in only 2 patients in the present series and is more frequently required for more extensive resections of the mediastinal trachea in patients with neoplasm. POSTOPERATIVE MANAGEMENT
Patients were extubated as soon as they were sufficientlyrecovered from anesthesia. Postoperative tracheostomy is usually unnecessary and should be avoided if possible, to obviate associated airway infection or pressure at the 368
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FIG. 7. Technique of maintaining cervical flexion for ten to fourteen days following tracheal resection.
anastomosis. Three patients developed glottic or supraglottic edema during the first 24 hours after operation (2 following laryngeal release, 1 due to hematoma in the cervical incision). All 3 were effectively managed by a short period (less than 24 hours) of orotracheal intubation with an uncuffed tube and the concomitant administration of steroids and inhalation of a nebulized vasoconstrictor. Cervical flexion undoubtedly reduces tension at the anastomosis, and it is maintained for at least ten days after operation. During the past four years, postoperative neck flexion has been very effectively maintained by a stout silk suture tethering the skin of the chin to the skin of the chest (Fig. 7). This apparently barbaric maneuver is surprisingly well tolerated by the patient and is completely dependable in maintaining flexion at all times.
Case Report One case history illustrates many of the principles of management described. A 45-year-old woman was transferred from another hospital four months following recognition of a stricture in the mediastinal trachea. Prior to her admission to Toronto General Hospital, the stricture had been managed by repeated bronchoscopic dilatations, silver nitrate cauterization, and prolonged stenting with a long metal tracheostomy tube introduced through a cervical stoma. At the time of admission to Toronto General Hospital, bronchoscopy revealed acute mucosal inflammation and ulceration of the entire trachea
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between the cervical stoma and the carina. A long stricture was identified in the mediastinal trachea which extended to within 1 cm. of the carina. T h e stricture was dilated with a No. 7 bronchoscope, and a tracheogram was obtained the day after admission (Fig. 8A). T h e damaged segment was 5 cm. in length, but the entire trachea was markedly softened from stoma to carina and collapsed on coughing, as shown in Figure 8A. T h e tracheostomy tube was removed and the cervical stoma allowed to close, treatment with appropriate antibiotics was instituted, and airway patency was maintained by frequent bronchoscopic dilatations. During the ensuing eight weeks, inflammatory changes in the tracheal mucosa above and below the damaged segment gradually subsided. A repeat tracheogram showed a marked decrease in tracheal softening and collapse except in the irreparably damaged 5-cm. segment, which was now precisely delineated. Figure 8B shows this second preoperative tracheogram, and the length of the excised damaged segment is shown by comparison with the postoperative tracheogram, Figure 8C. At operation, exposure was obtained with a collar incision and median
A
B
C
FIG. 8. Interval tracheograms illustrating the management of a 5-cm. stricture resected f r o m the mediastinal trachea. (A) Film obtained o n the second hospital day. T h e markedly softened trachea is seen t o collapse o n coughing. (B) Tracheogram obtained eight weeks later, showing decreased tracheal softening and collapse following closure of the tracheostomy and a course of antibiotic treatment t o reduce mucosal inflammation. ( C ) Postoperative tracheogram following excision of the diseased segment (upper arrow: vocal cords; lower arrow: carina).
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FIG. 9. A good result is seen in roentgenograms obtained two months postoperatively.
sternotomy. A 5-cm. segment of mediastinal trachea was excised and additional mobilization obtained by laryngeal release. Although we were prepared to extend the incision and mobilize the right pulmonary hilum, this proved unnecessary, and primary anastomosis with satisfactory tension was possible. Three hours after operation the patient developed severe supraglottic edema associated with a hematoma in the cervical incision. An airway was established by intubation with a small, uncuffed orotracheal tube, the hematoma was evacuated, and a small bleeding artery was ligated. Within a further six hours the patient was extubated, and no further airway obstruction occurred. Thereafter, the patient had difficulty with uncoordinated swallowing and aspiration which did not resolve completely until six weeks after operation. A good result was obtained, and the patient was free from clinical evidence of airway obstruction at last follow-up, thirteen months after resection. Oblique and anteroposterior projections of a tracheogram obtained two months after operation are illustrated in Figure 9.
References 1. Andrews, M. J., and Pearson, F. G. The incidence and pathogenesis of tracheal injury following cuffed tube tracheostomy with assisted ventilation: An analysis of a two year prospective study. Ann. Surg. 173:249, 1971. 2. Dedo, H. H., and Fishman, N. H. Laryngeal release and sleeve resection for tracheal stenosis. Ann. Otol. 78285, 1969. 3. Fishman, N. H., Dedo, H. H., Hamilton, W. K., Hinchcliffe, W. A., and Roe, B. B. Postintubation tracheal stenosis. Ann. Thorac. Surg. 8:47, 1969. 4. Grillo, H. C. Surgical approaches to the trachea. Surg. Gynec. Obstet. 129: 347, 1969. VOL. 12, NO.
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5. Grillo, H. C. Surgery of the trachea. Curr. Probl. Surg., (July) 1970. 6. Lindholm, C. E. Prolonged endotracheal intubation. Acta Anaesth. Scand. Suppl. 33, 1969. 7. Pearson, F. G., Goldberg, M., and DaSilva, A. J. A prospective study of tracheal injury complicating tracheostomy with a cuffed tube. Ann. Otol. 77:867, 1968. 8. Pearson, F. G., Goldberg, M., and DaSilva, A. J. Tracheal stenosis complicating tracheostomy with cuffed tubes. Arch. Surg. (Chicago) 97:380, 1968. 9. Webb, W. R., and Fitts, C. T. Evaluation of Hytrast as bronchographic medium. Amer. Surg. 29:491, 1963.
Discussion DR. KEN L. HARDY (Oakland, Calif.): Dr. Pearson’s extensive experience has again contributed to our knowledge about the treatment of a serious iatrogenic complication of assisted respiration. Even with such a thorough type of prospective analysis to detect early stricture, a 20% incidence seems surprisingly high. Equally interesting is the report of more stomal than cuff lesions. We have not had a stomal stricture in more than six years and attribute this to the following technique: A circular plug of anterior tracheal wall at the third ring is excised in an unhurried manner over an endotracheal tube. T h e round opening is made large enough to accommodate easily a tracheostomy tube of the selected diameter, which is then gently inserted over a lubricated, smoothly beveled obturator to prevent damage to the posterior mucosa as the tube is withdrawn. Linear or cruciate incisions which require a forceable thrust for introduction of the tube may cause wall fracture, mucosal tears, and one or more inwardly bent flaps, predisposing to repair by scar at the stoma. A migratory cuff or loose inflation line can cause further stomal irritation. I would like to ask Dr. Pearson what types of cuffed tubes were used in his patients. Were they passed over an obturator, and how were the stomas created? Our 7 strictures were all at the cuff level and occurred earlier than two and a half years ago. Five of these were detected early and were cured by dilatations. Two, diagnosed late, required segmental resection. With this experience we began concentrating on prevention of cuff stricture, and we have not had any in the past thirty months. We believe that this is due mainly to two factors: (1) intensive instruction to nurses and therapists not to exceed minimal occluding volume (MOV) when inflating the cuff; MOV is that volume of air required to cause seal at 30 cm. H,O; (2) the use of a tube introduced to this society last year which has an integral balloon that inflates to a symmetrical sausage contour. This allows MOV to be achieved at lower actual tracheal pressures than when an eccentric circular balloon is used. This tube with its pivotal neck flange rides free in the tracheal lumen, avoiding tip impingement and mucosal ulceration, and its
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obturator allows for gentle passage. Shiley Laboratories have manufactured an identical tube with a larger, 300% volume balloon of the same contour. This tube is presently being evaluated. DR. NICHOLAS J. DEMOS(Jersey City, N.J.): Since prevention is preferable to treatment, I would like to present to you a new and exciting idea in tracheostomy cuffs. The cuff is very easily fashioned from sterilized foam rubber ordinarily used for the prevention of decubitus ulcers. After the paper is peeled off, the foam rubber is glued onto any type of tracheostomy cannula and secured with a silk ligature. For easy insertion of the tube, the paper, following removal, is wrapped around the cuff to reduce its volume. When the cuff is about three-quarters through the tracheal opening, the paper is easily removed and the remainder of the tube is inserted. After the cuff had been in use in a group of dogs for up to three days, only slight inflammation was present on the mucaa. Measurement of cuff pressure against the tracheal wall revealed a maximum pressure of only 28 cm. HzO, which compares very favorably with pressures of up to 250 mm. Hg exerted by the usual inflatable cuffs. Having obtained permission from our appropriate committee, we are testing this new cuff on our patients with equal success.
DR. MILTONV. DAVIS(Dallas, Tex.): I join with the two previous discussants in referring to the importance of prevention, and I think that little more need be said about that. The reason I requested time to discuss this fine paper is because I think that a word should be said about the indwelling stent. The stent lies just below the vocal cords and just above the carina. Originally we anchored these stents with wire and with nonabsorbable synthetic sutures. More recently, we have simply put them in and let them lie below the cords, and they stay quite well in that location with or without a tracheostomy tube. The usual methods of dilation are not nearly as effective as the indwelling stent. Later, if operation becomes necessary, the indwelling stent provides the condition set down by Dr. Pearson and his associates of allowing the inflammation to recede to its maximum before an operation is performed. We started putting in stents for that purpose, and we were able to effect what amounted to a surgical cure without ever doing the operation. DR. PEARSON: I thank all three discussants for their comments. In answer to Dr. Hardy's questions: We have used two types of tubes during the period of the prospective study, the Portex tube and the James red rubber tube. There was no difference in the incidence of stricture following use of either of these tubes. Recently we have used the Portex tube with a hyperinflated cuff, as described by Dr. Bendixen in Boston. We have seen VOL. 12, NO.
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2 strictures following the use of this modification, but we do not yet have enough data to know if the incidence of stricture is actually less. I agree with Dr. Hardy that the incidence of stoma1 stenosis observed in our series is exceptionally high. I think one of the main reasons for this is that the prospective study has resulted in detection of lesions at the stoma which otherwise might easily have been overlooked since the obstruction is not severe. I believe that some stomal narrowing will result regardless of the type of tracheostomy tube used or the type of incision employed. One inevitably loses some tracheal cartilage anteriorly, and in patients who are hypoperfused or on steroids we have found a still more extensive loss of cartilage at the stomal site. Again, I would emphasize that the stomal stricture most commonly produces a mild or moderate degree of obstruction. Of the 60 strictures reported today, 37 were at the stomal level but only 18 were sufficiently severe to require resection. Twenty of the 26 lesions at the cuff level required resection. I anticipate that in the future we will use tubes of modified design which cause less damage than those used in the past, and I think Dr. Hardy’s modification is definitely a step in that direction. Ultimately, I believe we may find a mechanism other than the inflatable cuff for airway control during assisted ventilation. Dr. Demos has suggested an ingenious and novel method for securing airway occlusion during assisted ventilation. Time will tell how effective this modification will be. At the moment, I would be concerned that this technique will not permit precise control of lateral tracheal wall pressures. Dr. Davis makes a good point about the use of an indwelling stent as definitive management for tracheal stenosis. A number of patients have been successfully treated in this way and reported in the literature. Not all strictures, however, can be reliably managed by this method. If full-thickness loss of tracheal wall has occurred, stenting techniques are unsuccessful in our experience. Although our otolaryngologists have successfully treated a few patients in this way, in others, restenosis developed after the stent was removed even though it had been left in place for periods up to six months. Resection was ultimately required in these patients.
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