Management of Acquired Tracheal 0 bstructions in Infancy By Dale G. Johnson and David R. Stewart
A
N INCREASED INCIDENCE of acquired tracheal stenosis has accompanied advances in airway management and respiratory care of infants. The location of the stenosis is usually subglottic at the cricoid level where the tracheal diameter is smallest. The cause of the stenosis appears related to mechanical trauma associated with prolonged endotracheal intubation. Neonatal intensive care units have experienced an increased survival in very small premature infants with respiratory distress through the use of intubation and sophisticated ventilatory support. In addition, the value of airway intubation for the majority of infant surgical procedures is undisputed. The occasional complication of postintubation subglottic stenosis does not contraindicate airway intubation, but attempts at prevention and a simplified approach to management when this complication does occur are very much needed. Traditional management of subglottic stenosis has required performance of a tracheostomy to relieve airway obstruction while a variety of techniques has been applied to restore an adequate lumen to the upper airway. The simple approach of waiting 2-5 yr with a tracheostomy in place will allow subsequent decannulation of some infants due to growth of the larynx and trachea. A subglottic narrowing in these cases may persist, but the restricted lumen seems to increase with overall growth of the trachea, and elimination of the tracheostomy eventually is tolerated. Treatment by multiple tracheal dilatations with a tracheostomy tube in place has also been sanctioned by previous authorities, but the results in many cases have been disappointing. Fearon and Ellis’ reported that 18 of 23 cases treated with dilatations required tracheostomy care from l-3 yr, while five still had a tracheostomy beyond 3 yr. The combination of tracheal dilatation with direct injection of adrenocortical steroids into the subglottic scar has been advocated more recently. The steroid injections appear to decrease the necessary number of dilatations, but reported cases have required from six to twenty dilatations over a 120-180-day interval.2 In 1970, Birck described a method for treating subglottic stenosis with a molded intraluminal plastic stent combined with dilatations and the systemic administration of corticosteroids.3 The final addition with a direct injection of steroid into the tracheal stricture plus the dilatation, intraluminal stent, and systemic steroids was reported by Othersen in 1974.4 This paper outlines an experience with yet another therapeutic modality: the direct endoscopic resection of the narrowed ring of subglottic scar. Endoscopic From the Departments of Surgery and Pediatrics, University of Utah College of Medicine, and the Division of Pediatric Surgery, Primary Children’s Medical Center, Salt Lake City, Utah, Presented before the 6th Annual Meeting of the .4merican Pediatric Surgical Association, San Juan, Puerto Rico, April 10-12, 1975. Address/or reprint requests: Dale G. Johnson, M.D.. Department of Surgery, Primary Children’s Medical Center, 320 Twjelfth Ave.. Salt Lake City. Utah 84103. o 1975 by Grune & Stratton, Inc. Journal of Pediatric Surgery, Vol. 10, No. 5 (October), 1975
709
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AND STEWART
resection is proposed not as a replacement but as a supplement to the other treatment methods. Where applicable, it can reduce the number of tracheal dilatations required, and it may eliminate the need for tracheostomy altogether in particularly favorable cases. TECHNIQUE Control of the infant’s airway is an absolute necessity prior to any attempt at endoscopic resection of subglottic scar. If a tracheostomy has not been performed prior to evaluation of the subglottic stenosis, this evaluation must be performed cautiously with a ventilating bronchoscope. The magnified view through the O”, infant bronchoscopic telescope is essential. If the smallest 2.5 sheath (4.0 mm O.D. at flare) will not pass through the stenosis at the cricoid level, we believe a tracheostomy should be performed before proceeding with further manipulation. If the 3.0 sheath (5.2 mm O.D.) will pass with minimal resistance but the 3.5 (6.5 mm O.D.) will not, the thickness of the stenotic ring should be evaluated before making a decision regarding tracheostomy. Thin webs and those that are predominantly in the anterior one-half circumference of the trachea may be resected without requiring temporary supplemental tracheostomy. The thicker scars and those that are circumferential are more difficult to manage. If amenable to endoscopic resection, the complicated scars are more safely managed with a staged approach involving quadrant excisions and a protecting tracheostomy. We have allowed an interval of 2-4 wk between stages to permit reepithelialization over the previously excised quadrant. The instrument we have found most useful for this procedure is the infant urethral resectoscope with a size-13 insulated sheath (3.5 x 5.0 mm O.D.) and the 0’ rod lens telescope with fiber optic illumination (K. Storz, Storz Endoscopy-America, Inc., Los Angeles, Calif.). Adequate ventilation can be maintained in an infant as a semiclosed system by attaching the anesthesia circuit to the irrigating channel of the resectoscope sheath (Fig. I). The resectoscope is introduced into the larynx and through the cords by using a laryngoscope for exposure. Thereafter, the instrument is advanced to or beyond the cricoid level of the trachea by direct vision through the telescope. Prior introduction of a fine suction catheter to lie beside
n
Fig. 1. Infant msecroscop with airway connection through irrigation channel.
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TRACHEAL
711
OBSTRUCTIONS
the resectoscope sheath in the trachea is useful to evacuate any vapor that may arise when the cutting loop passes through the subglottic scar. If the airway is not protected by a tracheostomy, the resection should not be initiated until it has been determined that ventilation is adequate and under complete control. The resectoscope sheath is then withdrawn to a level just proximal to the subglottic ring and distal to the vocal cords. The cutting loop is extended behind the web of scar as a hook and the cutting current is then applied. One should start with a very low current and increase until effective cutting is obtained without the bursting effect from excess heat, which will damage surrounding tissue. Very short pulses of current produced by quick taps on the foot pedal will provide precise control during the excision. A one-half circumference thin web can be excised entirely. Thicker circumferential scars should be attacked in three or four stages. We avoid any excision in the posterior midline to eliminate the danger of esophageal perforation. Following the resection, a mixture of triamcinolone (40 mg/ml) with hyaluronidase (150 r/ml), mixed 5 ml/l ml, can be injected in O.l-ml volumes into the four quadrants of the subglottic lesion. If ballooning of the mucosa follows the injection, an endotracheal tube is left in place for 1-2 hr and then the infant is extubated in the intensive care unit. We have also administered systemic dexamethasone (2 mg/5 kg) at the time of resection and 12 hr later without any evidence for or against its effectiveness in limiting postoperative swelling.
CLINICAL
MATERIAL
A summary
of the clinical management of nine patients with postintubation subglottic stenosis is presented in Table 1. Patient A.R. (case 9) is listed twice because her recurrence was preceded by a symptom-free interval and her treatment involved resection with a protecting tracheostomy the first time and resection without a tracheostomy the second. Case histories are described below.
Case I A.A.,
a female weighing
1,568 g, was managed
with
nasotracheal
intubation
and
mechanical
ventilation for severe respiratory distress syndrome (RDS). Numerous attempts at intubation over the next 2 mo were unsuccessful. A tracheostomy was performed after 68 days of intubation. Total initial hospitalization was 8 mo. Tracheoscopy at 8 mo and 15 mo revealed severe subglottic tracheal stenosis with a lumen approximately 2 mm. Reevaluation at 34 mo revealed a 6.0-mm tracheal lumen, and the patient was successfully decannulated.
Case 2 K.G., a female weighing 2,982 g, had repair of esophageal atresia with TEF by another surgeon. She developed a stricture, a small anastomotic leak, and subsequent recurrence of the TEF. DiviTable 1. Summary of Clinical Management of Nine Patients With Portintubation Subglottic Stenosis Interval
Core No./ Patient
Age (mo)
Weight when intubated (9)
lntubation time (days)
between extubotion and obstruction (days)
Trocheostomy duration (dovs)
Dilatation (No.)
Steroid injections
Endorcopic resections
(No.)
(No.)
stent _ (days) (mo)
1jA.A.
34
1568
68
0
1033
0
0
0
36
2jK.G.
8
2982
15
0
345
4
1
2
28
3jD.L.
22
160
0
0
2
24
4jJ.A.
3
0
180
4
1
0
25
0
-
-
-
2358
7 52
5/C.R.
9
1022
1
6
5
3323
1
150
540 0
12
6jR.R.
1
0
0
7/M.H.
6
950
15
90
63
4
2
2
11
0lH.T.
9
3054
3
3
1
6-R
9jA.R.
9
1740
3jA.R.
17
-
-
3
270
5
240 -
0 64 -
32
NA 14
4
1
2
6
3
2
2
2
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JOHNSON AND STEWART
sion of the recurrent tracheoesophageal fistula (TEF) was performed 3 mo after the original surgery and then division of a patent ductus arteriosus 1 wk later because of congestive heart failure. Nasotracheal intubation was required for management over a l5-day interval, and because of inability to extubate the patient she had a tracheostomy. Attempted tracheal decannulation 35 days later revealed a subglottic stricture that would not admit any size tracheal dilator. At 8 mo of age the infant was referred for reevaluation of her subglottic stenosis. Tracheoscopy revealed a 3.0-mm, tight subglottic ring. Dilatation allowed passage of a 4.0 mm O.D. bronchoscope through the stenosis to the tracheostomy site where the tracheal lumen was occluded by granuloma. The tracheal granuloma was excised and then the subglottic stenosis was endoscopically excised in two stages with a 4-mo interval. A minimal residual was then injected with triamcinolone, dilated, and the tracheostomy tube was removed. Twenty-eight-month follow-up has shown no recurrence of stridor.
Case 3 D.L., a l9-mo male had an emergency tracheostomy on the neurosurgical service for respiratory insufficiency following repair of lumbar meningomyelocele. The initial tracheostomy did not function well, and a second tracheostomy was performed 5 wk later at a lower site. Three months later he was seen in consultation regarding tracheal extubation. Tracheoscopy revealed a subglottic granuloma and tracheal granuloma filling the lumen from the tracheostomy to the cricoid. The cords were mobilized and the subglottic web and tracheal granuloma were excised in two stages. Final evaluation revealed an epithelialized lumen with no stenosis, and the patient was successfully decannulated.
Case 4 J.A., a male weighing 2,358 g, was born with esophageal atresia without TEF. A gastrostomy was performed using endotracheal anesthesia. Two weeks later a cervical esophagostomy was performed when hope for direct anastomosts was abandoned in favor of subsequent esophageal substitution. Temporary cord palsy followed mobilization of the proximal esophagus, requiring three to four attempts at extubation over 7 days until the parents finally gave permission for tracheostomy. The cord palsy recovered spontaneously, but decannulation was prevented 2 mo later because a tight but thin subglottic web was seen at tracheoscopy performed prior to tracheostomy tube removal. The subglottic web was eliminated with four tracheal dilatations and one intralesional injection of steroids. The tracheostomy tube was subsequently removed.
Case 5 C.R., a female weighing 1,022 g, was managed with nasotracheal intubation and mechanical ventilation for severe RDS. Six attempts at extubation were unsuccessful, and tracheostomy was performed after 52 days of intubation. Tracheoscopy 7 mo later revealed a 3.0-mm subglottic stenosis secondary to a thick, circumferential, shaggy scar at the cricoid level. There was additional polypoid granuloma at the tracheostomy site and also at the tube tip above the left main bronchus. Tracheal dilatations were tried on two occasions along with resection of granuloma at the tracheostomy site. The subglottic ring was then incised in two quadrants and six more dilatations were tried during systemic administration of D-penicillamine to interfere with collagen cross-linkage.’ The subglottic scar seemed to soften, but the tracheal lumen could not be increased. A molded portex stent was then positioned in the trachea, as described by Birck,3 and systemic prednisone was administered. The stent was removed after 32 days and prednisone was tapered because the anchoring buttons cut through the anterior neck. The subglottic lumen was improved but not yet adequate. After three endoscopic resections of granuloma at the tracheostomy site plus three subglottic dilatations the tracheostomy tube was removed. Seventeen days later, the tracheostomy was reconstructed because of recurrent pneumonia and inability to handle secretions.
Case 6 R.R., a male weighing 3,323 g, was born with esophageal atresia and TEF. Because of aspiration pneumonia at diagnosis he was first intubated for staging gastrostomy and then again 3 days later
713
ACQUIRED TRACHEAL OBSTRUCTIONS
for extrapleural repair. Reintubation for lo-min intervals was performed twice in the postoperative period for suctioning. Five months later, the infant was tracheoscoped for evaluation of inspiratory stridor. A thin, subglottic membrane with a 4-mm lumen was easily dilated. Subsequent tracheoscopy 6 mo later revealed no evidence of the previous stenotic web.
Case 7 M.H., a female weighing 950 g, was managed with nasotracheal intubation and mechanical ventilation for severe RDS complicated by systemic sepsis and necrotizing enterocolitis. Her initial intubation was recorded as traumatic, and she was extubated and reintubated five times. Her total duration for nasotracheal intubation was 15 days. Three months after discharge, at 6 mo of age, she was readmitted with severe inspiratory-expiratory stridor secondary to upper airway obstruction. She was deeply cyanotic in oxygen. Tracheoscopy revealed a large granulomatous subglottic obstruction arising from the right tracheal wall at the cricoid level. Tracheostomy was performed, and 3 days later an endoscopic resection of the granuloma with dilatation and intralesional injection of triamcinolone was accomplished. Two additional dilatations, a second injection with triamcinolone, and final endoscopic resection of granuloma at the cephalad aspect of the tracheostomy stoma allowed decannulation 63 days after tracheostomy. In the subsequent year. there were no symptoms of stridor even during upper respiratory infections.
Case 8 H.T., a female weighing 3,054 g, had repair of esophageal atresia and TEF by another surgeon. Because of postoperative pulmonary problems, a nasotracheal tube was utilized for assisted ventilation over a 3-day period. She was extubated and subsequently discharged in good condition. Nine months later, she developed foreign body obstruction of the esophagus. History revealed inspiratory stridor and retractions on exertion over the previous several months. Tracheoscopy, following removal of the vegetable-matter plug in the esophagus, revealed a subglottic web that offered moderate resistance to insertion of the smallest 4.0-mm O.D. infant bronchoscope. Only the anterior one-half circumference at the cricoid level was involved, and the web was membranous in nature. Three tracheal dilatations at ICday intervals produced little improvement. Endoscopic resection of the web without a distal tracheostomy was easily accomplished. Subsequent tracheoscopy revealed a normal lumen, and the patient has remained without symptoms.
Case 9 A.R., a female weighing 1,740 g, was treated with nasotracheal intubation and mechanical ventilation for severe RDS. Successful extubation was performed after 5 days, and she was discharged at 33 days of age. No symptoms were apparent until 8 mo later when she developed croup, which would not respond to IPPB treatment with racemic epinephrine. Tracheoscopy revealed a severe stenosis below the cords at the cricoid level. A transverse bar across the lumen left two smaller l.O-2.0-mm orifices above and below the bar. A 2.0-mm endotracheal tube was forced against considerable resistance through the upper orifice to provide an airway during performance of tracheostomy. One week later, the subglottic bar was excised with the resectoscope. One quadrant was also excised from the ring of scar, which then was dilated and injected with triamcinolone. Following a second quadrant resection and two subsequent dilatations the trachea was decannulated. The patient had no stridor or evidence of airway obstruction until 6 mo later when she developed a severe upper respiratory infection. When the stridor did not clear she was again tracheoscoped. A small recurrent rim of subglottic scar was injected and dilated. This was not sufficient to eliminate stridor, so it was then excised and injected in two stages. A tracheostomy was not required for these resections, and her stridor was eliminated.
DISCUSSION
Postintubation tracheal stenosis in adults has been managed successfully by segmental resection and end-to-end anastomosis.6 These adult lesions are most often caused by pressure from a balloon cuff in the cervical trachea. Balloon
714
JOHNSON
AND STEWART
cuffs are not used with endotracheal tubes for infants because a tube of appropriate size permits a larger lumen with a relatively airtight fit at the level of the cricoid and to a lesser extent at the cords. Mechanical trauma and pressure necrosis from a tight-fitting tube at the cricoid level, however, produces a subglottic tracheal stenosis that is very difficult to manage. Resection and end-to-end anastomosis cannot be applied to subglottic stenosis without destructive effects on the growth and function of the larynx through removal of the cricoid. The risk of interference with laryngeal growth also limits the applicability of other operative approaches involving open excision of subglottic scar. Doig et al.7 have recently reported surgical enlargement of the cricoid ring in infants by anterior insertion of an ellipse of costal cartilage between the edges of the incised cricoid and first tracheal ring. They reported four successes, two deaths, and one failure in seven children with this operation. The survivors were said to have normal speech. This operation is attractive in concept for subglottic stenosis resistant to other methods, but more experience is required to demonstrate its safety and effectiveness. Tracheostomy, time, and multiple dilatations have been the conventional but frustrating form of management for subglottic stenosis. Many infants and parents have been committed to the trials and hazards of tracheostomy care for 2-5 yr. Plastic tracheostomy tubes have reduced some of the complications involving tube occlusion, erosion, airway perforation, and so on, but the demands of humidification and sterile suctioning, the repeated pulmonary infections, and the constant fear of airway obstruction are all very difficult for parents to handle. Case 1 illustrates that growth and the passage of time will result in resolution of subglottic stenosis and permit tracheal decannulation in some infants even though the initial obstruction is extreme. Her 3-yr requirement for tracheostomy was less than many children have required, but the morbidity and inconvenience were still considerable. Case 6 was an example of a very thin web that responded to a single dilatation without protecting tracheostomy. Case 4 did have a tracheostomy for 6 mo, but his subglottic stenosis was eliminated with only four dilatations combined with one intralesional injection of triamcinolone. The other options of waiting several years for tracheal growth or the more complicated treatment with intratracheal stent and systemic steroids are very much less desirable for these simple lesions, in our opinion. Cases 2, 3, 5, 7, 8, and 9 all had high-grade stenosis with thick scar and granuloma formation that did not respond to simple dilatation. All but one of these cases also had intralesional injection of triamcinolone on one or more occasions. Our experience does not allow any conclusion about the effectiveness or lack of effectiveness of steroid injection. The rationale for this modality has been reviewed by Othersen. It was the addition of endoscopic resection of the subglottic ring, however, that seemed to make the largest contribution to our success. As our experience and our confidence in the safety of this technique has increased, we have tended to dilate less and resect earlier. The interval in some cases of 90-270 days between initial extubation and recognized obstruction from subglottic stenosis was somewhat surprising and
ACQUIRED
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715
OBSTRUCTIONS
points up the need for awareness that late obstruction may occur in infants with long-term intubation. Delayed stenosis and the development of obstruction has also been reported following intubation in adults.6 Significant subglottic stenosis following intubation as brief as 3 days was also unexpected. Endoscopic resection of a moderate subglottic stenosis without first performing a tracheostomy is something we have done only twice, but when it can be accomplished safely the inconvenience for child and parents alike is considerably lessened. The one case in which we made little progress using dilatations, intralesional triamcinolone, and endoscopic resection (Case 5) was finally managed with a molded intratracheal stent and systemic prednisone. The planned 42-day course was cut short at 32 days because of a mechanical complication, but the method did seem helpful in expanding the subglottic lumen. Subsequent partial restenosis did occur, and repeat tracheostomy was performed 17 days after decannulation because of recurrent pulmonary infections. Further experience with the stent technique might eliminate the mechanical problems we encountered, and we recognize that a stent may be necessary when simpler methods have failed. Our success so far with endoscopic resection, however, leads us to reserve the stent and systemic steroids for extensive lesions refractory to other methods. SUMMARY
Endoscopic resection of tracheal subglottic stenosis can be performed safely and effectively. With careful selection, some stenotic rings can be excised without the requirement for prior tracheostomy. Endoscopic resection does not supplant other methods of dilatation, injection, or stenting of subglottic scars, but early resection in appropriate cases may reduce the number of dilatations and obviate the need for a stent and systemic steroids. REFERENCES 1. Fearon BY, Ellis D: The management of long-term airway problems in infants and children. Am Otolaryngol80:669-677, 1971 2. Waggoner LG. Belenky W, Clark CE: Treatment of acquired subglottic stenosis. Am Otolaryngol 82:822-826, 1973 3. Birck HG: Endoscopic repair of laryngeal stenosis. Trans Am Acad Ophthalmol Otolaryngol 74:140-143, 1970 4. Othersen HB Jr: The technique of intraluminal stenting and steroid administration in the treatment of tracheal stenosis in children, J Pediatr Surg 9:683-690. 1974
5. Ninmi ME: A defect in the intramolecular and intermolecular cross-lining of collagen caused by penicillamine. J Biol Chem 243: 14% 1466. 1968 6. Geffin B, Grill0 HC, Cooper JD, et al: Stenosis following tracheostomy for respiratory care. JAMA 216:1984-1988. 1971 7. Doig C, Eckstein HB, Waterston DJ: Surgical treatment of laryngeal and subglottic obstruction in infancy and childhood. Z Kinderchir 12:299-303, 1973
Discussion Dr. L. Leape (Boston): It’s a privilege to discuss this paper because I think it’s really an excellent contribution. The major lesson that comes through loud and clear, is that we should have a flexibility of approach. When some of us get up and advocate a new method of handling some
716
JOHNSON
AND STEWART
condition, too frequently people assume that that’s the only way to handle it. I think Dr. Johnson has made it clear that different patients need different approaches. The great majority of patients, I think, will respond to dilatations and certainly very few need a stent. I would like to emphasize that this lesion should be very, very rare. In our experience it is. At any one time we have six or eight children with endotracheal tubes in place in our neonatal intensive care unit and yet, in the last 2 yr we have not had a single case of acquired subglottic stenosis. Why does it occur? It’s because a tube is put in that’s too big and this is typically what happens when it’s done by an inexperienced operator. It isn’t surprising that it can occur when the tube has been in only 24 hr because if the tube is too big, it’s going to cause local ischemia, and 24 hr is plenty of time to permit the development of a severe subglottic stenosis. I would submit that if the intubation is done properly, this is a disease you will not see. Dr. Johnson has emphasized the details of this technique. One must be very careful in setting the current, in not taking too much, and in effect, doing it under careful control. I have had no experience with endoscopic resection, but I have recently had a patient who was treated with electrocautery and I want to show it, because I think it demonstrates what can go wrong if you don’t do it with the kind of care that Dr. Johnson has demonstrated. (slide) This is a child who, shortly after birth, was found to have severe respiratory distress and an emergency tracheostomy was done. She was found to have a subglottic web and various procedures were undertaken to resect it and to dilate it, including several treatments with electrocautery. These were unsuccessful and ultimately we received her when she was about 6 mo of age. At bronchoscopy this is what we saw. (slide) There was absolutely no lumen whatsoever in her trachea. We were not even able to pass a fine lacrimal duct probe. We took her to the operating room and opened her trachea and found that the entire trachea from the cords to the tracheostomy stoma had been obliterated. To our surprise there also was some metaplastic bone formation. We literally carved out a channel and put in a silastic stent and this is what her trachea looked like after the first stent had been in for 2 wk. (slide) We put in the smallest tube we could find and then replaced it gradually with a bigger one. This situation represents what we have to guard against if we are going to be using electrocautery. Dr. B. Othersen (Charleston): I think that Dr. Johnson has contributed something innovative which will be of value. I would agree that each patient should be individualized, and I would be the first to admit that our technique is not applicable to all patients. Our experience now consists of eight stenoses, six of which were secondary to endotracheal tubes. I think the condition is more common than we think and that some of these children only get into trouble when they develop a respiratory infection. There are probably lots of children who grow up with tracheal stenosis that is undetected. In addition to the tube which is too large, many of our patients have had tubes which have been attached to respirators. The to and fro motion of the respirator causes the tube to rub the trachea and contributes to the stenosis. I would caution you against the prolonged use of steroids. In one patient we used steroids for about 4 mo; 2 yr later, he has small posterior cataracts which have not influenced his vision. I think that these were caused by the steroids. In summary, I would agree with Dr. Johnson that the incidence of tracheal stenosis is increasing and that we ought to look for it. I would agree that there are various degrees of stenosis and that different individuals should be treated in different ways. If it’s a severe stenosis, then they may need resection, steroid injection, and a stent. Dr. M. Johnson (Oakland): In the past few months we have also started using the infant resectoscope for this type of lesion and we have had the same results that Dr. Johnson has had. If the patient is much older than 2 yr, this instrument is too short to get to the proper place to do the resection. Perhaps Storz will make a longer instrument if this becomes a popular procedure. I would like to ask Dr. Johnson if he feels that he can adequately ventilate the child through the side arm of the resectoscope while doing the resection? We used the infant cytoscope for bronchoscopy before Storz came out with their ventilating bronchoscope and found them very effective for ventilating the small infant through the irrigating channel. The resectoscope, we feel, is inadequate to ventilate a child. Dr. H. Hendren (Boston): We have used a similar endoscopic approach for obstructing webs in the larynx and trachea of about a dozen children since 1971, but with a slightly different technique. Instead of using the infant rectoscope, which is rather large, we have used the infant bronchoscope. For a cutting electrode we employ a No. 3 ureteral catheter and its wire stylette. An assistant pushes out enough wire beyond the catheter, which acts as an insulating sleeve, and
ACQUIRED
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717
he also holds the bovie to the wire. The operator uses the foot switch to control the application of current. We use very briefapplication of cutting current. This works very effectively and cuts a limited area. By comparison, a resectoscope loop is much larger and comes in contact with a greater area of tissue. We have used this same technique for destroying urethral valves in small babies. Most pediatric surgeons are entirely familiar with using pediatric bronchoscopes, whereas some may not be fully familiar with using the pediatric resectoscope. Thus, we think this method has three advantages, namely that the equipment is smaller, it may afford slightly greater accuracy in what is being cut, and it is equipment available to most pediatric surgeons currently. Dr. D. Johnson (closing): 1 am grateful for all the comments, and I don’t think there is any basic disagreement. Our aim is to make the punishment fit the crime. You don’t always need maximal treatment for a simple lesion. 1 have been surprised that several of our patients have presented late. The first group in our series could not be extubated, and they required immediate tracheostomy. However, other patients were extubated and were home as long as 6 mo before an upper respiratory infection precipitated obstruction and caused serious difficulty. We have followed Dr. Othersen’s advice about steroids, I don’t know whether or not they work either, but we have used a variety of treatment methods in our series. I agree with Morris Johnson’s comments about the resectoscope being too short for a larger child. Our approach has been to get the tracheostomy out in early infancy, so we haven’t really had this problem. The children in our series have been under 2 yr at the time of resection. We haven’t tried approaching the lesion through the tracheostomy stoma. I think it would be difficult to resect the subglottic web and be careful of the cords when doing it through the stoma. With reference to Dr. Hendren’s comment about the insulated electrode through the bronchoscope. we actually did our first case that way. I agree that is an effective method. The bronchoscope gives a better view with better ventilation. You can do a little more cutting with the resectoscope if you are familiar with it, but if you are not, it is dangerous.
A
N INCREASED INCIDENCE of acquired tracheal stenosis has accompanied advances in airway management and respiratory care of infants. The location of the stenosis is usually subglottic at the cricoid level where the tracheal diameter is smallest. The cause of the stenosis appears related to mechanical trauma associated with prolonged endotracheal intubation. Neonatal intensive care units have experienced an increased survival in very small premature infants with respiratory distress through the use of intubation and sophisticated ventilatory support. In addition, the value of airway intubation for the majority of infant surgical procedures is undisputed. The occasional complication of postintubation subglottic stenosis does not contraindicate airway intubation, but attempts at prevention and a simplified approach to management when this complication does occur are very much needed. Traditional management of subglottic stenosis has required performance of a tracheostomy to relieve airway obstruction while a variety of techniques has been applied to restore an adequate lumen to the upper airway. The simple approach of waiting 2-5 yr with a tracheostomy in place will allow subsequent decannulation of some infants due to growth of the larynx and trachea. A subglottic narrowing in these cases may persist, but the restricted lumen seems to increase with overall growth of the trachea, and elimination of the tracheostomy eventually is tolerated. Treatment by multiple tracheal dilatations with a tracheostomy tube in place has also been sanctioned by previous authorities, but the results in many cases have been disappointing. Fearon and Ellis’ reported that 18 of 23 cases treated with dilatations required tracheostomy care from l-3 yr, while five still had a tracheostomy beyond 3 yr. The combination of tracheal dilatation with direct injection of adrenocortical steroids into the subglottic scar has been advocated more recently. The steroid injections appear to decrease the necessary number of dilatations, but reported cases have required from six to twenty dilatations over a 120-180-day interval.2 In 1970, Birck described a method for treating subglottic stenosis with a molded intraluminal plastic stent combined with dilatations and the systemic administration of corticosteroids.3 The final addition with a direct injection of steroid into the tracheal stricture plus the dilatation, intraluminal stent, and systemic steroids was reported by Othersen in 1974.4 This paper outlines an experience with yet another therapeutic modality: the direct endoscopic resection of the narrowed ring of subglottic scar. Endoscopic From the Departments of Surgery and Pediatrics, University of Utah College of Medicine, and the Division of Pediatric Surgery, Primary Children’s Medical Center, Salt Lake City, Utah, Presented before the 6th Annual Meeting of the .4merican Pediatric Surgical Association, San Juan, Puerto Rico, April 10-12, 1975. Address/or reprint requests: Dale G. Johnson, M.D.. Department of Surgery, Primary Children’s Medical Center, 320 Twjelfth Ave.. Salt Lake City. Utah 84103. o 1975 by Grune & Stratton, Inc. Journal of Pediatric Surgery, Vol. 10, No. 5 (October), 1975
709
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resection is proposed not as a replacement but as a supplement to the other treatment methods. Where applicable, it can reduce the number of tracheal dilatations required, and it may eliminate the need for tracheostomy altogether in particularly favorable cases. TECHNIQUE Control of the infant’s airway is an absolute necessity prior to any attempt at endoscopic resection of subglottic scar. If a tracheostomy has not been performed prior to evaluation of the subglottic stenosis, this evaluation must be performed cautiously with a ventilating bronchoscope. The magnified view through the O”, infant bronchoscopic telescope is essential. If the smallest 2.5 sheath (4.0 mm O.D. at flare) will not pass through the stenosis at the cricoid level, we believe a tracheostomy should be performed before proceeding with further manipulation. If the 3.0 sheath (5.2 mm O.D.) will pass with minimal resistance but the 3.5 (6.5 mm O.D.) will not, the thickness of the stenotic ring should be evaluated before making a decision regarding tracheostomy. Thin webs and those that are predominantly in the anterior one-half circumference of the trachea may be resected without requiring temporary supplemental tracheostomy. The thicker scars and those that are circumferential are more difficult to manage. If amenable to endoscopic resection, the complicated scars are more safely managed with a staged approach involving quadrant excisions and a protecting tracheostomy. We have allowed an interval of 2-4 wk between stages to permit reepithelialization over the previously excised quadrant. The instrument we have found most useful for this procedure is the infant urethral resectoscope with a size-13 insulated sheath (3.5 x 5.0 mm O.D.) and the 0’ rod lens telescope with fiber optic illumination (K. Storz, Storz Endoscopy-America, Inc., Los Angeles, Calif.). Adequate ventilation can be maintained in an infant as a semiclosed system by attaching the anesthesia circuit to the irrigating channel of the resectoscope sheath (Fig. I). The resectoscope is introduced into the larynx and through the cords by using a laryngoscope for exposure. Thereafter, the instrument is advanced to or beyond the cricoid level of the trachea by direct vision through the telescope. Prior introduction of a fine suction catheter to lie beside
n
Fig. 1. Infant msecroscop with airway connection through irrigation channel.
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the resectoscope sheath in the trachea is useful to evacuate any vapor that may arise when the cutting loop passes through the subglottic scar. If the airway is not protected by a tracheostomy, the resection should not be initiated until it has been determined that ventilation is adequate and under complete control. The resectoscope sheath is then withdrawn to a level just proximal to the subglottic ring and distal to the vocal cords. The cutting loop is extended behind the web of scar as a hook and the cutting current is then applied. One should start with a very low current and increase until effective cutting is obtained without the bursting effect from excess heat, which will damage surrounding tissue. Very short pulses of current produced by quick taps on the foot pedal will provide precise control during the excision. A one-half circumference thin web can be excised entirely. Thicker circumferential scars should be attacked in three or four stages. We avoid any excision in the posterior midline to eliminate the danger of esophageal perforation. Following the resection, a mixture of triamcinolone (40 mg/ml) with hyaluronidase (150 r/ml), mixed 5 ml/l ml, can be injected in O.l-ml volumes into the four quadrants of the subglottic lesion. If ballooning of the mucosa follows the injection, an endotracheal tube is left in place for 1-2 hr and then the infant is extubated in the intensive care unit. We have also administered systemic dexamethasone (2 mg/5 kg) at the time of resection and 12 hr later without any evidence for or against its effectiveness in limiting postoperative swelling.
CLINICAL
MATERIAL
A summary
of the clinical management of nine patients with postintubation subglottic stenosis is presented in Table 1. Patient A.R. (case 9) is listed twice because her recurrence was preceded by a symptom-free interval and her treatment involved resection with a protecting tracheostomy the first time and resection without a tracheostomy the second. Case histories are described below.
Case I A.A.,
a female weighing
1,568 g, was managed
with
nasotracheal
intubation
and
mechanical
ventilation for severe respiratory distress syndrome (RDS). Numerous attempts at intubation over the next 2 mo were unsuccessful. A tracheostomy was performed after 68 days of intubation. Total initial hospitalization was 8 mo. Tracheoscopy at 8 mo and 15 mo revealed severe subglottic tracheal stenosis with a lumen approximately 2 mm. Reevaluation at 34 mo revealed a 6.0-mm tracheal lumen, and the patient was successfully decannulated.
Case 2 K.G., a female weighing 2,982 g, had repair of esophageal atresia with TEF by another surgeon. She developed a stricture, a small anastomotic leak, and subsequent recurrence of the TEF. DiviTable 1. Summary of Clinical Management of Nine Patients With Portintubation Subglottic Stenosis Interval
Core No./ Patient
Age (mo)
Weight when intubated (9)
lntubation time (days)
between extubotion and obstruction (days)
Trocheostomy duration (dovs)
Dilatation (No.)
Steroid injections
Endorcopic resections
(No.)
(No.)
stent _ (days) (mo)
1jA.A.
34
1568
68
0
1033
0
0
0
36
2jK.G.
8
2982
15
0
345
4
1
2
28
3jD.L.
22
160
0
0
2
24
4jJ.A.
3
0
180
4
1
0
25
0
-
-
-
2358
7 52
5/C.R.
9
1022
1
6
5
3323
1
150
540 0
12
6jR.R.
1
0
0
7/M.H.
6
950
15
90
63
4
2
2
11
0lH.T.
9
3054
3
3
1
6-R
9jA.R.
9
1740
3jA.R.
17
-
-
3
270
5
240 -
0 64 -
32
NA 14
4
1
2
6
3
2
2
2
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JOHNSON AND STEWART
sion of the recurrent tracheoesophageal fistula (TEF) was performed 3 mo after the original surgery and then division of a patent ductus arteriosus 1 wk later because of congestive heart failure. Nasotracheal intubation was required for management over a l5-day interval, and because of inability to extubate the patient she had a tracheostomy. Attempted tracheal decannulation 35 days later revealed a subglottic stricture that would not admit any size tracheal dilator. At 8 mo of age the infant was referred for reevaluation of her subglottic stenosis. Tracheoscopy revealed a 3.0-mm, tight subglottic ring. Dilatation allowed passage of a 4.0 mm O.D. bronchoscope through the stenosis to the tracheostomy site where the tracheal lumen was occluded by granuloma. The tracheal granuloma was excised and then the subglottic stenosis was endoscopically excised in two stages with a 4-mo interval. A minimal residual was then injected with triamcinolone, dilated, and the tracheostomy tube was removed. Twenty-eight-month follow-up has shown no recurrence of stridor.
Case 3 D.L., a l9-mo male had an emergency tracheostomy on the neurosurgical service for respiratory insufficiency following repair of lumbar meningomyelocele. The initial tracheostomy did not function well, and a second tracheostomy was performed 5 wk later at a lower site. Three months later he was seen in consultation regarding tracheal extubation. Tracheoscopy revealed a subglottic granuloma and tracheal granuloma filling the lumen from the tracheostomy to the cricoid. The cords were mobilized and the subglottic web and tracheal granuloma were excised in two stages. Final evaluation revealed an epithelialized lumen with no stenosis, and the patient was successfully decannulated.
Case 4 J.A., a male weighing 2,358 g, was born with esophageal atresia without TEF. A gastrostomy was performed using endotracheal anesthesia. Two weeks later a cervical esophagostomy was performed when hope for direct anastomosts was abandoned in favor of subsequent esophageal substitution. Temporary cord palsy followed mobilization of the proximal esophagus, requiring three to four attempts at extubation over 7 days until the parents finally gave permission for tracheostomy. The cord palsy recovered spontaneously, but decannulation was prevented 2 mo later because a tight but thin subglottic web was seen at tracheoscopy performed prior to tracheostomy tube removal. The subglottic web was eliminated with four tracheal dilatations and one intralesional injection of steroids. The tracheostomy tube was subsequently removed.
Case 5 C.R., a female weighing 1,022 g, was managed with nasotracheal intubation and mechanical ventilation for severe RDS. Six attempts at extubation were unsuccessful, and tracheostomy was performed after 52 days of intubation. Tracheoscopy 7 mo later revealed a 3.0-mm subglottic stenosis secondary to a thick, circumferential, shaggy scar at the cricoid level. There was additional polypoid granuloma at the tracheostomy site and also at the tube tip above the left main bronchus. Tracheal dilatations were tried on two occasions along with resection of granuloma at the tracheostomy site. The subglottic ring was then incised in two quadrants and six more dilatations were tried during systemic administration of D-penicillamine to interfere with collagen cross-linkage.’ The subglottic scar seemed to soften, but the tracheal lumen could not be increased. A molded portex stent was then positioned in the trachea, as described by Birck,3 and systemic prednisone was administered. The stent was removed after 32 days and prednisone was tapered because the anchoring buttons cut through the anterior neck. The subglottic lumen was improved but not yet adequate. After three endoscopic resections of granuloma at the tracheostomy site plus three subglottic dilatations the tracheostomy tube was removed. Seventeen days later, the tracheostomy was reconstructed because of recurrent pneumonia and inability to handle secretions.
Case 6 R.R., a male weighing 3,323 g, was born with esophageal atresia and TEF. Because of aspiration pneumonia at diagnosis he was first intubated for staging gastrostomy and then again 3 days later
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ACQUIRED TRACHEAL OBSTRUCTIONS
for extrapleural repair. Reintubation for lo-min intervals was performed twice in the postoperative period for suctioning. Five months later, the infant was tracheoscoped for evaluation of inspiratory stridor. A thin, subglottic membrane with a 4-mm lumen was easily dilated. Subsequent tracheoscopy 6 mo later revealed no evidence of the previous stenotic web.
Case 7 M.H., a female weighing 950 g, was managed with nasotracheal intubation and mechanical ventilation for severe RDS complicated by systemic sepsis and necrotizing enterocolitis. Her initial intubation was recorded as traumatic, and she was extubated and reintubated five times. Her total duration for nasotracheal intubation was 15 days. Three months after discharge, at 6 mo of age, she was readmitted with severe inspiratory-expiratory stridor secondary to upper airway obstruction. She was deeply cyanotic in oxygen. Tracheoscopy revealed a large granulomatous subglottic obstruction arising from the right tracheal wall at the cricoid level. Tracheostomy was performed, and 3 days later an endoscopic resection of the granuloma with dilatation and intralesional injection of triamcinolone was accomplished. Two additional dilatations, a second injection with triamcinolone, and final endoscopic resection of granuloma at the cephalad aspect of the tracheostomy stoma allowed decannulation 63 days after tracheostomy. In the subsequent year. there were no symptoms of stridor even during upper respiratory infections.
Case 8 H.T., a female weighing 3,054 g, had repair of esophageal atresia and TEF by another surgeon. Because of postoperative pulmonary problems, a nasotracheal tube was utilized for assisted ventilation over a 3-day period. She was extubated and subsequently discharged in good condition. Nine months later, she developed foreign body obstruction of the esophagus. History revealed inspiratory stridor and retractions on exertion over the previous several months. Tracheoscopy, following removal of the vegetable-matter plug in the esophagus, revealed a subglottic web that offered moderate resistance to insertion of the smallest 4.0-mm O.D. infant bronchoscope. Only the anterior one-half circumference at the cricoid level was involved, and the web was membranous in nature. Three tracheal dilatations at ICday intervals produced little improvement. Endoscopic resection of the web without a distal tracheostomy was easily accomplished. Subsequent tracheoscopy revealed a normal lumen, and the patient has remained without symptoms.
Case 9 A.R., a female weighing 1,740 g, was treated with nasotracheal intubation and mechanical ventilation for severe RDS. Successful extubation was performed after 5 days, and she was discharged at 33 days of age. No symptoms were apparent until 8 mo later when she developed croup, which would not respond to IPPB treatment with racemic epinephrine. Tracheoscopy revealed a severe stenosis below the cords at the cricoid level. A transverse bar across the lumen left two smaller l.O-2.0-mm orifices above and below the bar. A 2.0-mm endotracheal tube was forced against considerable resistance through the upper orifice to provide an airway during performance of tracheostomy. One week later, the subglottic bar was excised with the resectoscope. One quadrant was also excised from the ring of scar, which then was dilated and injected with triamcinolone. Following a second quadrant resection and two subsequent dilatations the trachea was decannulated. The patient had no stridor or evidence of airway obstruction until 6 mo later when she developed a severe upper respiratory infection. When the stridor did not clear she was again tracheoscoped. A small recurrent rim of subglottic scar was injected and dilated. This was not sufficient to eliminate stridor, so it was then excised and injected in two stages. A tracheostomy was not required for these resections, and her stridor was eliminated.
DISCUSSION
Postintubation tracheal stenosis in adults has been managed successfully by segmental resection and end-to-end anastomosis.6 These adult lesions are most often caused by pressure from a balloon cuff in the cervical trachea. Balloon
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cuffs are not used with endotracheal tubes for infants because a tube of appropriate size permits a larger lumen with a relatively airtight fit at the level of the cricoid and to a lesser extent at the cords. Mechanical trauma and pressure necrosis from a tight-fitting tube at the cricoid level, however, produces a subglottic tracheal stenosis that is very difficult to manage. Resection and end-to-end anastomosis cannot be applied to subglottic stenosis without destructive effects on the growth and function of the larynx through removal of the cricoid. The risk of interference with laryngeal growth also limits the applicability of other operative approaches involving open excision of subglottic scar. Doig et al.7 have recently reported surgical enlargement of the cricoid ring in infants by anterior insertion of an ellipse of costal cartilage between the edges of the incised cricoid and first tracheal ring. They reported four successes, two deaths, and one failure in seven children with this operation. The survivors were said to have normal speech. This operation is attractive in concept for subglottic stenosis resistant to other methods, but more experience is required to demonstrate its safety and effectiveness. Tracheostomy, time, and multiple dilatations have been the conventional but frustrating form of management for subglottic stenosis. Many infants and parents have been committed to the trials and hazards of tracheostomy care for 2-5 yr. Plastic tracheostomy tubes have reduced some of the complications involving tube occlusion, erosion, airway perforation, and so on, but the demands of humidification and sterile suctioning, the repeated pulmonary infections, and the constant fear of airway obstruction are all very difficult for parents to handle. Case 1 illustrates that growth and the passage of time will result in resolution of subglottic stenosis and permit tracheal decannulation in some infants even though the initial obstruction is extreme. Her 3-yr requirement for tracheostomy was less than many children have required, but the morbidity and inconvenience were still considerable. Case 6 was an example of a very thin web that responded to a single dilatation without protecting tracheostomy. Case 4 did have a tracheostomy for 6 mo, but his subglottic stenosis was eliminated with only four dilatations combined with one intralesional injection of triamcinolone. The other options of waiting several years for tracheal growth or the more complicated treatment with intratracheal stent and systemic steroids are very much less desirable for these simple lesions, in our opinion. Cases 2, 3, 5, 7, 8, and 9 all had high-grade stenosis with thick scar and granuloma formation that did not respond to simple dilatation. All but one of these cases also had intralesional injection of triamcinolone on one or more occasions. Our experience does not allow any conclusion about the effectiveness or lack of effectiveness of steroid injection. The rationale for this modality has been reviewed by Othersen. It was the addition of endoscopic resection of the subglottic ring, however, that seemed to make the largest contribution to our success. As our experience and our confidence in the safety of this technique has increased, we have tended to dilate less and resect earlier. The interval in some cases of 90-270 days between initial extubation and recognized obstruction from subglottic stenosis was somewhat surprising and
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points up the need for awareness that late obstruction may occur in infants with long-term intubation. Delayed stenosis and the development of obstruction has also been reported following intubation in adults.6 Significant subglottic stenosis following intubation as brief as 3 days was also unexpected. Endoscopic resection of a moderate subglottic stenosis without first performing a tracheostomy is something we have done only twice, but when it can be accomplished safely the inconvenience for child and parents alike is considerably lessened. The one case in which we made little progress using dilatations, intralesional triamcinolone, and endoscopic resection (Case 5) was finally managed with a molded intratracheal stent and systemic prednisone. The planned 42-day course was cut short at 32 days because of a mechanical complication, but the method did seem helpful in expanding the subglottic lumen. Subsequent partial restenosis did occur, and repeat tracheostomy was performed 17 days after decannulation because of recurrent pulmonary infections. Further experience with the stent technique might eliminate the mechanical problems we encountered, and we recognize that a stent may be necessary when simpler methods have failed. Our success so far with endoscopic resection, however, leads us to reserve the stent and systemic steroids for extensive lesions refractory to other methods. SUMMARY
Endoscopic resection of tracheal subglottic stenosis can be performed safely and effectively. With careful selection, some stenotic rings can be excised without the requirement for prior tracheostomy. Endoscopic resection does not supplant other methods of dilatation, injection, or stenting of subglottic scars, but early resection in appropriate cases may reduce the number of dilatations and obviate the need for a stent and systemic steroids. REFERENCES 1. Fearon BY, Ellis D: The management of long-term airway problems in infants and children. Am Otolaryngol80:669-677, 1971 2. Waggoner LG. Belenky W, Clark CE: Treatment of acquired subglottic stenosis. Am Otolaryngol 82:822-826, 1973 3. Birck HG: Endoscopic repair of laryngeal stenosis. Trans Am Acad Ophthalmol Otolaryngol 74:140-143, 1970 4. Othersen HB Jr: The technique of intraluminal stenting and steroid administration in the treatment of tracheal stenosis in children, J Pediatr Surg 9:683-690. 1974
5. Ninmi ME: A defect in the intramolecular and intermolecular cross-lining of collagen caused by penicillamine. J Biol Chem 243: 14% 1466. 1968 6. Geffin B, Grill0 HC, Cooper JD, et al: Stenosis following tracheostomy for respiratory care. JAMA 216:1984-1988. 1971 7. Doig C, Eckstein HB, Waterston DJ: Surgical treatment of laryngeal and subglottic obstruction in infancy and childhood. Z Kinderchir 12:299-303, 1973
Discussion Dr. L. Leape (Boston): It’s a privilege to discuss this paper because I think it’s really an excellent contribution. The major lesson that comes through loud and clear, is that we should have a flexibility of approach. When some of us get up and advocate a new method of handling some
716
JOHNSON
AND STEWART
condition, too frequently people assume that that’s the only way to handle it. I think Dr. Johnson has made it clear that different patients need different approaches. The great majority of patients, I think, will respond to dilatations and certainly very few need a stent. I would like to emphasize that this lesion should be very, very rare. In our experience it is. At any one time we have six or eight children with endotracheal tubes in place in our neonatal intensive care unit and yet, in the last 2 yr we have not had a single case of acquired subglottic stenosis. Why does it occur? It’s because a tube is put in that’s too big and this is typically what happens when it’s done by an inexperienced operator. It isn’t surprising that it can occur when the tube has been in only 24 hr because if the tube is too big, it’s going to cause local ischemia, and 24 hr is plenty of time to permit the development of a severe subglottic stenosis. I would submit that if the intubation is done properly, this is a disease you will not see. Dr. Johnson has emphasized the details of this technique. One must be very careful in setting the current, in not taking too much, and in effect, doing it under careful control. I have had no experience with endoscopic resection, but I have recently had a patient who was treated with electrocautery and I want to show it, because I think it demonstrates what can go wrong if you don’t do it with the kind of care that Dr. Johnson has demonstrated. (slide) This is a child who, shortly after birth, was found to have severe respiratory distress and an emergency tracheostomy was done. She was found to have a subglottic web and various procedures were undertaken to resect it and to dilate it, including several treatments with electrocautery. These were unsuccessful and ultimately we received her when she was about 6 mo of age. At bronchoscopy this is what we saw. (slide) There was absolutely no lumen whatsoever in her trachea. We were not even able to pass a fine lacrimal duct probe. We took her to the operating room and opened her trachea and found that the entire trachea from the cords to the tracheostomy stoma had been obliterated. To our surprise there also was some metaplastic bone formation. We literally carved out a channel and put in a silastic stent and this is what her trachea looked like after the first stent had been in for 2 wk. (slide) We put in the smallest tube we could find and then replaced it gradually with a bigger one. This situation represents what we have to guard against if we are going to be using electrocautery. Dr. B. Othersen (Charleston): I think that Dr. Johnson has contributed something innovative which will be of value. I would agree that each patient should be individualized, and I would be the first to admit that our technique is not applicable to all patients. Our experience now consists of eight stenoses, six of which were secondary to endotracheal tubes. I think the condition is more common than we think and that some of these children only get into trouble when they develop a respiratory infection. There are probably lots of children who grow up with tracheal stenosis that is undetected. In addition to the tube which is too large, many of our patients have had tubes which have been attached to respirators. The to and fro motion of the respirator causes the tube to rub the trachea and contributes to the stenosis. I would caution you against the prolonged use of steroids. In one patient we used steroids for about 4 mo; 2 yr later, he has small posterior cataracts which have not influenced his vision. I think that these were caused by the steroids. In summary, I would agree with Dr. Johnson that the incidence of tracheal stenosis is increasing and that we ought to look for it. I would agree that there are various degrees of stenosis and that different individuals should be treated in different ways. If it’s a severe stenosis, then they may need resection, steroid injection, and a stent. Dr. M. Johnson (Oakland): In the past few months we have also started using the infant resectoscope for this type of lesion and we have had the same results that Dr. Johnson has had. If the patient is much older than 2 yr, this instrument is too short to get to the proper place to do the resection. Perhaps Storz will make a longer instrument if this becomes a popular procedure. I would like to ask Dr. Johnson if he feels that he can adequately ventilate the child through the side arm of the resectoscope while doing the resection? We used the infant cytoscope for bronchoscopy before Storz came out with their ventilating bronchoscope and found them very effective for ventilating the small infant through the irrigating channel. The resectoscope, we feel, is inadequate to ventilate a child. Dr. H. Hendren (Boston): We have used a similar endoscopic approach for obstructing webs in the larynx and trachea of about a dozen children since 1971, but with a slightly different technique. Instead of using the infant rectoscope, which is rather large, we have used the infant bronchoscope. For a cutting electrode we employ a No. 3 ureteral catheter and its wire stylette. An assistant pushes out enough wire beyond the catheter, which acts as an insulating sleeve, and
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717
he also holds the bovie to the wire. The operator uses the foot switch to control the application of current. We use very briefapplication of cutting current. This works very effectively and cuts a limited area. By comparison, a resectoscope loop is much larger and comes in contact with a greater area of tissue. We have used this same technique for destroying urethral valves in small babies. Most pediatric surgeons are entirely familiar with using pediatric bronchoscopes, whereas some may not be fully familiar with using the pediatric resectoscope. Thus, we think this method has three advantages, namely that the equipment is smaller, it may afford slightly greater accuracy in what is being cut, and it is equipment available to most pediatric surgeons currently. Dr. D. Johnson (closing): 1 am grateful for all the comments, and I don’t think there is any basic disagreement. Our aim is to make the punishment fit the crime. You don’t always need maximal treatment for a simple lesion. 1 have been surprised that several of our patients have presented late. The first group in our series could not be extubated, and they required immediate tracheostomy. However, other patients were extubated and were home as long as 6 mo before an upper respiratory infection precipitated obstruction and caused serious difficulty. We have followed Dr. Othersen’s advice about steroids, I don’t know whether or not they work either, but we have used a variety of treatment methods in our series. I agree with Morris Johnson’s comments about the resectoscope being too short for a larger child. Our approach has been to get the tracheostomy out in early infancy, so we haven’t really had this problem. The children in our series have been under 2 yr at the time of resection. We haven’t tried approaching the lesion through the tracheostomy stoma. I think it would be difficult to resect the subglottic web and be careful of the cords when doing it through the stoma. With reference to Dr. Hendren’s comment about the insulated electrode through the bronchoscope. we actually did our first case that way. I agree that is an effective method. The bronchoscope gives a better view with better ventilation. You can do a little more cutting with the resectoscope if you are familiar with it, but if you are not, it is dangerous.
