Temporary and permanent restoration of airway continuity with the tracheal T-tube

Temporary and permanent restoration of airway continuity with the tracheal T-tube The advantages of the tracheal T -tube compared with a regular tracheostomy tube are a physiologic direction of air flow, preservation of laryngeal phonation, and superior patient acceptance. Between 1968 and 1991, 140 patients aged 7 months to 95 years underwent placement of T-, TY- (n = 7), or a modified extended T -tube (n = 4). Primary diagnosis was postintubation stenosis in 86 patients, burn injury in 13 patients, malignant airway tumors in 1 patients, and various disorders in 9 patients. Stenting with a silicone rubber tube was temporary in 31 patients and 14 underwent later operative reconstruction. Definitive permanent insertion was performed in 49 patients. A modified tube was used in 4 patients with left main bronchial stenosis with effective long-term palliation in 3. Postoperative airway obstruction prompted placement in 3 patients. Positioning of the T -tube above the vocal cords in 1 patients for subglottic stenosis was effective in 10. The T-tube was not tolerated in 8 patients (0 %) because of obstruction of the upper limb or aspiration. Five of 10 patients under the age of 10 years had airway obstruction necessitating tube removal. Long-term intubation in 11 patients exceeded 1 year in 49 patients and 5 years in 1 patients. Only 5 patients required tube removal for obstructive problems more than months after placement. The tracheal T -tube restores airway patency reliably with exceuent long-term resnlts and represents the preferred management of chronic airway obstruction not amenable to surgical reconstruction. (J THORAC CARDIOV ASC SURG 1994;107:600-6) Henning A. Gaissert, MD (by invitation), Hermes C. Grillo, MD, Douglas J. Mathisen, MD, and John C. Wain, MD (by invitation), Boston, Mass. Critical stenosis of the upper airway not amenable to surgical resection often necessitates a tracheostomy, either as a temporary measure or for long-term relief. Transient airway obstruction after operative reconstruction may also necessitate temporary intubation. Regular tracheostomy tubes are frequently preferred to maintain stomal patency because of the ease of insertion and subsequent change. However, they divert air flow from the nose, mouth, and larynx. Inhaled air reaches the lung at ambient temperature and without humidification. As a result of laryngeal exclusion, speech is recovered only From the General Thoracic Surgical Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Read at the Seventy-third Annual Meeting of The American Association for Thoracic Surgery, Chicago, Ill., April 5-8, 1993. Address for reprints: Hermes C. Grillo, MD, Massachusetts General Hospital, Boston MA 0114. Copyright 1994 by Mosby-Year Book, Inc. 00-53/94 $1.00 +.10 1/6/5065 when air passes around the tube or through fenestrations in the tube. Furthermore, a tracheostomy tube does not allow remodeling of the airway like a silicone rubber T-tube, which on occasion obviates surgical reconstruction. Because of these disadvantages and the potential of additional injury to the trachea from rigid tubes, an alternative solution to maintain a patent physiologic airway is desirable. The tracheal T-tube was introduced by Montgomery! in 1965 and was originally intended as a definitive treatment of tracheal stenosis. At the Massachusetts General Hospital silicone rubber stents have been used since 1968 for palliative and temporary stenting of the airway. Patients with focal and complex obstruction have tolerated T-tubes well. Success with these stents in the proximal trachea has prompted further modification to accommodate more distal airway stenoses. Although general anesthesia is required for insertion, the excellent long-term acceptance and absence of injury to the tracheal wall lead us to prefer T-tubes over regular tracheostomy tubes in patients with suitable anatomy. This retrospective analy- 600

The Journal of Thoracic and Volume 107, Number Gaissert et al. 6 0 1 Fig. 1. Straight stomal tract perpendicular to tracheal axis is important for optimal seating of T -tube. A, Oblique tract in long-standing tracheostomy. Dotted line shows intended incision. B, Corrected stomal tract with T-tube. sis reports our experience and details essential factors for success and failure in the use of the T -tube. Patients and methods Between 1968 and 1991,69 male and 71 female patients aged 7 months to 95 years (mean 43.8 years) underwent placement of at-tube, TY-tube (seven patients)? or a modified silicone rubber tube for left main bronchial stenosis after right pneumonectomy (four patients) in the General Thoracic Surgical Unit of the Massachusetts General Hospital.* Endobronchial stents have been used rarely and were excluded from this review. The T-tube was placed with the patient under general anesthesia as described previously.3-5 The airway is inspected with a rigid bronchoscope and accurate measurements are obtained. The T-tube is cut to exact length. Sharp edges at the tip thus created are rounded with sterilized sandpaper. We insert the tube through a tracheostomy and have not used endoscopic placement as described by Cooper and associates. 5 A precise fit is important to preclude kinking or friction on mobile mucosal surfaces such as the vocal cords or the subglottic wall, which could provoke granulations. If a long-standing tracheostomy *T-tubes and other tubes described were made as standard or specially ordered tubes by Hood Laboratories, Pembroke, MA. tube results in an oblique stomal tract, the tracheal stoma is revised during the operation to construct a tract perpendicular to the trachea (Fig. 1). Hegar dilators are used through the stoma when needed to dilate either the stoma or a stenotic trachea. The positions of the proximal and distal ends of the tube relative to the glottis, carina, and the lesion are checked with a Hopkins telescope. Often slight modifications in length are necessary. During this postplacement examination an appropriate 15 mm adapter from an endotracheal tube is fitted to the side arm of the T -tube for ventilation. High flows compensate for the loss of gases through the proximal limb of the tube. After insertion, a tracheostomy mask over the side arm of the T-tube provides humidified oxygen to prevent crusting within the tube so long as the side arm is kept open. The side arm is capped as soon as transglottic air flow is tolerated. Careful instructions in the care of these tubes are given to patients before discharge. 6 The use of the T -tube falls into three major categories: (1) for temporary stenting of the airway, () as definitive procedure for palliation, and (3) for complications of airwayreconstruction. 3, 4 The eventual outcome was not always predictable. Temporary airway support was provided in 31 patients, either before tracheal resection or as the only procedure. Forty-nine patients received a T-tube as a definitive procedure. Airway obstruction after operative reconstruction prompted placement in 3 patients. To identify the causes of T-tube failure, we reviewed

6 0 Gaissert et al. The Journal of Thoracic and February 1994 Table I. Diagnosis in 140 patients Diagnosis Postintubation stenosis Burn Malignant airway tumor Radiation stenosis Relapsing polychondritis Tracheomalacia Vascular malformation Sarcoidosis Trauma Necrotizing tracheitis Mucopolysaccharidosis Postpneumonectomy syndrome Tracheobronchomegaly (Mounier-Kuhn) Tuberculosis Idiopathic stenosis Tracheopathia osteoplastica No. 86 13 1 4 4 4 3 8 patients in whom T-tubes were not tolerated and had to be removed within the first months. Results The primary diagnosis in these 140 patients is detailed in Table I. Most had postintubation tracheal stenosis, burn injury, or malignant tumors of the airway. A diversity of rare airway disorders comprised the remainder. A component of tracheomalacia was frequently observed in postintubation injuries, but almost always in association with a stricture. Among the four cases of pure malacia, two were due to long-standing goiter, one was a residual after repair of a tracheoesophageal fistula, and one was due to an enlarged thymus in an infant. At the time of admission, 86 patients had tracheostomy tubes and four already had T-tubes in place. Two patients were referred after emergency transglottic intubation. Symptoms recorded in 35 patients without airway tubes on initial presentation were dyspnea in 9 (83%), stridor in 4 (67%), cough in seven (0%), and hoarseness in five (14%). One patient had severe halitosis as a result of chronic maceration from intratracheal Marlex mesh. In the remaining l3 patients, a T-tube was placed on an emergency basis in the immediate postoperative period to treat airway obstruction occurring after resection. Most lesions in 140 patients involved the trachea. However, endoscopic evaluation demonstrated subglottic involvement in 49 (36%) and main bronchial involvement in 1 patients (9%). T-tubes had been inserted previously in eight patients. Thirteen patients had multiple tracheostomies, one of them a total of four. Seventeen patients had undergone at least one laser treatment and 11 were treated with tracheal dilatation. Systemic steroids were Table II. Reason for failure of T-tube in 8 patients Reason for failure Airway obstruction Aspiration Obstruction and aspiration Patient noncompliance Postoperative secretions Patient request Tracheobronchitis used elsewhere in seven patients solely to treat tracheal disease. Temporary use. Fourteen patients received T-tubes before operative reconstruction. Indications for preoperative use were tracheal inflammation with uncertain stability of the wall, planned reduction of steroid medication, and medical problems warranting a delay. T-tubes were inserted for a mean duration of 11.5 months (range weeks to 5 years). Ultimately, nine patients underwent tracheal, one patient laryngotracheal, and one patient tracheobronchial resection and reconstruction. Laryngeal fissure was performed in two patients for subglottic resection, and one patient underwent tracheal reconstruction with skin flap advancement elsewhere. None of these patients received T-tubes after the operation. Among the 16 patients for whom temporary T-tube placement was the sole procedure, there were seven with burn stenoses, four with postintubation tracheal stenoses, two with short malacic segments at the stoma related to intubation, one with postintubation subglottic stenosis, one with tracheomalacia caused by goiter, and one with tracheopathia osteoplastica. 7 The common denominator of those lesions that allowed later extubation was either extensive tracheal involvement with an inflammatory process (e.g., burn) or a short anatomic narrowing. In both cases, there was preservation of cartilage and no permanent loss of mural stability. Tubes remained for a mean period of 0.9 months (3 months to 9 years). However, circumscribed areas of narrowing generally necessitated only 4 to 6 months of stenting. One patient with a 3 cm long postintubation stenosis after a previously failed resection elsewhere underwent successful stent extraction 9 years after first insertion. When the need for postoperative intubation is expected, tracheal resection is generally avoided. One additional patient underwent T -tube placement for a brief period after tracheal resection to guard a segment of uncertain stability above the anastomosis. In only two patients were T-tubes placed at the time of tracheal resection and reconstruction. Definitive use. T-tubes were placed permanently for No. 19 3

The Journal of Thoracic and Volume 107, Number Gaissert et al. 6 0 3 unresectable tumor in six patients. Four patients had unresectable squamous cell carcinomas originating in or invasive to the larynx and trachea. Their survival after T-tube placement was 1 to 17 months. Two patients had extensive, unresectable adenoid cystic carcinoma. One patient died 10 months later. The other patient underwent replacement of the tube years after initial insertion and was lost to follow-up thereafter. Forty-three patients had unresectable benign tracheal stenosis, either because of a limited length of normal, uninvolved trachea or because of contraindications to resection such as advanced cardiopulmonary disease and long-term steroid therapy. Twenty-seven patients with benign lesions are currently alive 5 months to 16 years after tube placement (mean 55.3 months), and 15 patients died after 1 month to 6 years (mean 1. months). One death was due to tracheal hemorrhage. The causes of death in 14 others were unrelated to the T -tube. Postoperative T-tube. Of 3 patients with T-tubes placed after prior tracheal resection, 16 patients underwent operation at the Massachusetts General Hospital and 16 were referred. When mechanical ventilation is not required, we prefer T -tube stenting to allow resolution of inflammation and postoperative edema rather than attempting a second resection immediately. Thirteen patients received their T-tubes in the immediate postoperative period, when symptoms of airway obstruction developed. Early placement was performed for suture line separation in six patients, for anastomotic stricture in six, and for a separated posterior mucosal flap after laryngotracheal reconstruction in one patient. In 19 patients, delayed airway obstruction necessitated T -tube placement 1 month to 14 years after tracheal reconstruction. In five patients, the T-tube was a bridge to a successful second resection 3 to 1 months after the first attempt. Five further patients were eventually decannulated without other procedures 1 to 1 months later. Eleven patients continue to have tracheal tubes: eight have T-tubes, two have TY-tubes, and in one patient a progressive and unreconstructable subglottic stenosis necessitated T -tube removal and insertion of a tracheostomy tube after 8 months. Six patients died with a postoperative tracheal stent 13 days to years after placement of causes not related to their T-tube. Five patients were lost to followup, one of them 4 years after decannulation. Tube modification. Stenosis of the main-stem bronchus presents a difficult management problem if operative resection is not possible. We have hesitated to place endotracheal or endobronchial stents without an external side arm, because in acute obstruction they might not be easily removed on an emergency basis. For palliation in four cases of left main bronchial stenosis, a modified Fig.. Modified extended T-tube (right) to stent a left mainstem bronchial stenosis. A long distal limb is created by joining a salivary bypass tube (left) with a regular T-tube of a mm larger diameter (middle). The top of the salivary bypass tube is trimmed and a side hole is cut. The tracheallimbs of the T -tube are shortened. Sharp edges are rounded and the T -tube is bonded with silicone rubber adhesive as a sleeve to the bypass tube. extended tube reaching into the main-stem bronchus was made from a T-tube and a salivary bypass tube in the operating room (Fig. ). A standard 1 or 14 mm T -tube was trimmed so that only a short sleeve of tube remained attached to the side arm. A salivary bypass tube, of a mm smaller diameter, was cut to extend beyond the bronchial stenosis distally and a short distance proximally. At the level of the side arm, a hole was cut in its side wall. Both tubes were joined with silicone rubber adhesive (Fig. ). This tube was used in two patients with postpneumonectomy syndrome and tracheal stenosis or malacia. 8 In one patient, the tube stented the airway successfully for 5 months after mediastinal repositioning, until tracheobronchial resection was performed with good result. In the other patient copious secretions developed after mediastinal repositioning and necessitated removal of the tube. Two further patients, one with a tuberculous stricture and

6 0 4 Gaissert et al. The Journal of Thoracic and February 1994 Table III. T-tubes in patients below age 0 years Patient Age Diagnosis Type o/tube Outcome Duration 0/ T-tube I 7 mo Vascular ring TY Alive with TY-tube 10 yr II mo Congenital stenosis T Failed 3 16 mo Postintubation stenosis T Failed 4 18mo Postintubation stenosis T Alive with T-tube 9 yr 5 yr Tracheomalacia T Failed 6 3 yr Postintubation stenosis T Alive without tube 3mo 7 4 yr Postintubation stenosis TY Alive with TY-tube 19mo 8 4 yr Postintubation stenosis T Died after tracheal reconstruction 5 mo 9 7 yr Postintubation stenosis T Failed 10 8 yr Postintubation stenosis T Failed 11 11 yr Burn T Alive without tube 5 yr 1 1 yr Postintubation stenosis T Died from tracheal hemorrhage 5 mo 13 IS yr Postintubation stenosis T Alive after tracheal reconstruction 3 mo 14 16 yr Mucopolysaccharidosis T Alive with T-tube IS mo IS 16 yr Postintubation stenosis T Alive without T-tube 8mo 16 17 yr Necrotizing tracheitis T Alive with T-tube 14 mo 17 17 yr Postpneumonectomy syndrome Extended T Alive without T-tube 7 mo 18 18 yr Postintubation stenosis T Alive after tracheal reconstruction 10mo 19 19 yr Burn T Alive without T-tube 4 yr 0 19 yr Postintubation stenosis T Alive after tracheal reconstruction 6mo 1 19 yr Traumatic tracheal laceration T Alive after tracheal reconstruction I mo the other with radiation-induced stricture and a surgically separated tracheoesophageal fistula, died and 4 years after palliative insertion. TY-tubes have also been modified by removal of one bronchial limb for pediatric use when the trachea and a single main bronchus are malacic. Failure of T-tube. In 8 of 140 patients (0%), the T-tube did not create a reliable airway and was removed within the first months. Reasons for removal are listed in Table II. Obstruction of the superior end was most common and usually necessitated opening of the side arm shortly after insertion. This usually occurred as a result of persistent glottic or subglottic edema or from granulations when the tube was in contact with the laryngeal sidewall. In two of four patients with tracheal stenosis and a history of sleep apnea, nocturnal airway obstruction was demonstrated after T-tube placement. Tracheal reconstruction was avoided and a tracheostomy tube was reinserted in these patients. The T-tube was inserted in 1 patients aged 19 and younger (Table III). The T-tube failed in five of 10 patients aged 10 years and younger. The high rate of early removal in this age group reflects the difficulties in stenting the small dimensions of a pediatric airway, particularly in the subglottic space. All five patients had obstruction, resulting from subglottic or vocal cord granulations (three patients), laryngeal edema (one patient), or without identifiable anatomic impediment (one infant). Obstruction of the lower end of the tube was rare and occurred as a result of distal tracheal granulations or from dried secretions. Distal obstruction is more common in the TY stent, because the tube is long and angulated and requires a perfect fit of the distance between stoma and carina to avoid inciting bronchial granulations. Aspiration ensued infrequently after T-tube insertion. Fixation of the tube at the stoma and interference with glottic closure may limit laryngeal elevation during swallowing and render epiglottic deflection or vocal cord closure incompetent. In most patients, aspiration was only a temporary disability. Unremitting aspiration necessitating tube removal developed in four patients-two patients with esophageal cancer, one patient with malignant tracheoesophageal fistula, and one patient with postintubation stenosis after esophagogastrectomy. Complications and deaths. Complications such as life-threatening airway obstruction, hemorrhage, or tracheoesophageal fistula formation are rare but do occur in the presence oft-tubes. Two of our patients had airway obstruction. Because both episodes occurred elsewhere, the role of the T-tube and whether the tube was removed at all when asphyxiation occurred were not clear. A 1-year-old patient with postintubation stenosis died at home 5 months after insertion of a T-tube of bleeding from the tracheostomy. In one patient with recurrent squamous cell carcinoma of the trachea after radiation therapy, a tracheoesophageal fistula developed shortly before the patient's death, while a T-tube was in place.

The Journal of Thoracic and Volume 107, Number Gaissert et al. 6 0 5 Long-term follow-up. In 11 patients the T-tube was successful in establishing a long-term airway (Table IV). Intubation was continued for more than 1 year in 49 patients and in 1 patients exceeded 5 years. Our longest follow-up extends to 0 years. Once the tube was tolerated well beyond months, late problems were unlikely. Only five patients required a later switch to a tracheostomy tube, owing to crusting when the side arm was left open for long periods or to subglottic stenosis. Clinical evaluation in 33 patients currently living with a T-tube demonstrates mild or absent respiratory symptoms in the majority. Seven have normal exercise tolerance. Mild dyspnea on exertion or cough is present in 16, and 10 patients have marked dyspnea on exertion or wheezing. Most in this group have pulmonary parenchymal disease. Discussion The T-tube is the preferred tracheal stent for stenosis of the upper airway, when surgical reconstruction cannot be accomplished and dilation provides inadequate relief. The T -tube offers the patient with a functional larynx the closest available approximation to a normal airway. The lower airways remain humidified, voice is preserved, the tube is socially acceptable, and daily care is easy. We have not buried the external side arm.9 Immediate access via the side arm provides an added measure of security. Subglottic or laryngeal edema, unreconstructable subglottic stenosis, and pediatric airway disease were frequently associated with stent obstruction. Subglottic stenosis alone did not preclude stenting, so long as a subglottic space of sufficient size was preserved. Prevention of laryngeal edema and of interference with glottic function is important. A short course of steroids is occasionally administered after tube insertion to minimize glottic edema. Although T -tubes had to be removed in 0% of our patients, this did not preclude other treatment options. Placement of the T-tube through the vocal cords, as reported by Cooper and associates,3 was tolerated in 10 of 1 patients with subglottic stenosis. This technique has been particularly useful in patients with inhalation injury.1o When the tube rests above the vocal cord, aspiration is prevented by approximation of the false cords and deflection of the epiglottis. Two patients with supraglottic tubes required tube removal because of aspiration. The T-tube is used temporarily in tracheal strictures to allow superficial tracheitis to subside, to correct proximal strictures at subglottic or glottic level, and to improve the patient's general condition. Only rarely in very limited strictures does prolonged use of a T-tube lead to a stable airway after removal of the tube. In only 16 of 140 Table IV. Duration of T-tube intubation in 11 patients Duration of intubation No, Less than 1 rno 5 1 to 3 rno 1 3 to 1 rno 46 I to 5 yr 37 Longer than 5 yr 1 patients (11 %) did T -tube placement lead to a functional airway after its removal without other intervention. Expandable wire stents have been suggested as an alternative to silicone rubber tubes in benign strictures of trachea and main bronchi, II but they are poorly tolerated in the presence of inflammation. They may migrate ll and their removal may be difficult. 1 Their safety in longterm intubation has not been established. REFERENCES 1. Montgomery WW. T-tube tracheal stent. Arch OtolaryngoI1965;8:30-1.. Westaby S, Jackson JW, Pearson FG. A bifurcated silicone rubber stent for relief of tracheobronchial obstruction. J THORAC CARDIOVASC SURG 198;83:414-7. 3. Cooper JD, Todd TRJ, lives R, Pearson FG. Use of the silicone tracheal T-tube for the management of complex tracheal injuries. J THORAC CARDIOV ASC SURG 1981 ;8:559-68. 4. Landa L. The tracheal T -tube: in tracheal surgery. In: Grillo HC, Eschapasse H, eds. International trends in general thoracic surgery. Vol. Philadelphia: WB Saunders, 1987:14-3. 5. Cooper JD,PearsonFG,PattersonGA,etal. Use of silicone stents in the management of airway problems. Ann Thorac Surg 1989;47:371-8. 6. Dempsey R. Nursing manual and home care instructions: tracheal and thoracic T-tubes. Hood Laboratories, Pembroke, Mass, 199. 7. Patterson GA, Mark EJ, Grillo HC. Case records of the Massachusetts General Hospital. N Engl J Med 199;37: 151-8. 8. Grillo HC, Shepard JAO, Mathisen DJ, Kanarek DJ. Postpneumonectomy syndrome: diagnosis, management, and results. Ann Thorac Surg 199;54:638-51. 9. Keszler P. The tracheal T -tube: for indwelling intubation as an alternative management method. In: Grillo HC, Eschapasse H, eds. International trends in general thoracic surgery. Vol. Philadelphia: WB Saunders, 1987:133-7. 10. Gaissert HA, Lofgren RH, Grillo HC. Upper airway compromise after inhalation injury: complex strictures oflarynx and trachea and their management. Ann Surg [In press]. II. Wallace MJ, Charnsangavej C, Ogawa K, et al. Tracheobronchial tree: expandable metallic stents used in experi-

6 0 6 Gaissert et al. The Journal of Thoracic and February 1994 mental and clinical applications. Radiology 1986;158:309-1. 1. NashefSAM, Dromer C, Velly JF, Labrousse L, Couraud L. Expanding wire stents in benign tracheobronchial disease: indications and complications. Ann Thorac Surg 199;54:937-40. Discussion Dr. Tom R. DeMeester (Los Angeles, Calif). Did the distal limb of the tube ever cause an erosion in the distal portion of the left main-stem bronchus? Dr. Wain. Yes. One of the patients needed to have the tube removed because of excessive secretions and the development of granulation tissues. No transmural erosions have occurred, but granulation formation has developed at the distal tip, particularly if the tube is not well seated or if the diameter of the tube relative to the surrounding airway is too small. Dr. Thomas R. J. Todd (Ottawa, Ontario, Canada). Your success rate is similar to the results that Joel Cooper reported on a smaller group from Toronto a few years ago. However, you have pointed out the specific problems in the patients who have glottic and subglottic stenoses. In those patients in whom you had to remove the tube because of obstruction at the upper end or because of aspiration in those patients with glottic and subglottic strictures, did you convert any of those to T-tubes brought up through the vocal cords? I noticed that there were several patients in whom you did bring the tube up through the vocal cords. Were any of those converted from tubes that were below the cords and that caused problems? Dr. Wain. Twelve patients had subglottic stenoses and in 10 of those the tube was brought up above the cords. I do not have the figures on the exact conversion rate, but 10 of those 1 did tolerate supraglottic extension of the tube. As experience has been gained with the procedure, we have tried to assess, at the time of initial placement, whether the sense is that the tube will seat properly in the subglottic space when the patient has a subglottic stenosis or whether it will be necessary to bring it above the cords. In general, if there is not a clear space in the conus elasticus between the inferior aspect of the cords and the top of the tube, it is advisable to place it initially and bring it above the cords to just below the supraglottic folds. Dr. Harold C. Urschel, Jr. (Dallas, Tex.). At Dr. Grillo's and Dr. Cooper's recommendations, in 197 we placed a stent for a supraglottic injury extending all the way to the carina. Subsequently we have one over 0 years, one over 15 years, and two over 10 years that have remained as the patient's permanent trachea. Two of them are above the vocal cords, both of these patients have "good" voices with their false cords. We have to change the T -tubes every year because they turn color and degenerate slightly. Initially in one patient we had severe trouble with granulations. This T -tube is an excellent alternative to tracheal reconstruction in the very long, damaged trachea. Dr. Thomas Egan (Chapel Hill, N.C). Could you elaborate on your use of this tube in the pediatric age group? Specifically, how small a stent will work? Dr. Wain. I believe the inner luminal diameter of the tubes can be as small as 4 or 6 mm. However, we do have great trouble placing these tubes in younger pediatric patients. In five of our 10 patients under 10 years of age, the tubes needed to be removed, most commonly because of proximal airway obstruction. Clearly in children less than 10 years of age there is great difficulty getting these tubes to work properly. Dr. Joel D. Cooper (St. Louis, Mo.). Do you use the bifurcation stents and the bronchial stents? If so, what was the distinction between using a free-standing stent, for example, in the left main bronchus, and using the modified salivary tube? I was not certain whether the problem was an isolated left bronchial problem and you chose to use a very long tube, including the horizontal limb coming out of a stoma, or whether it was a localized problem, in which case could you have used just a localized endoluminal stent rather than the T-tube. Dr. Wain. In the four cases described here, an endobronchial tube was not placed. In two of them there was a component of carinal stenosis and in two there was a postpneumonectomy circumstance. Although there was compression and stenosis of the bronchus, there was no firm margin on which to seat an endobronchial stent.