D PEDIATRIC LARYNGOTRACHEALRECONSTRUCTION

ROBIN T. COTTON, MD

The compromised pediatric airway is a difficult surgical problem that is very different from the same situation inan adult. Stenotic lesions vary widely in their size, extent, and location in the airway, requiring an extensivearray of procedures for their optimal surgical management. In addition, the overall health status of pediatricairway patients has become increasingly important in the planning of their care. Gastroesophageal reflux,pulmonary function, and the condition of the entire airway must be evaluated thoroughly before proceedingwith laryngotracheal reconstruction. Laser procedures, division of the cricoid cartilage, the use of cartilaginousgrafts, stenting, single-stage reconstruction, resection and anastomosis, and conservative management are someof the currently available approaches to planning laryngotracheal reconstruction for specific circumstances.

The physician's first approach to laryngotracheal re­construction (LTR) is often accompanied by feelings ofanxiety and awkwardness. The compromised pediatricairway is a difficult surgical problem with many con­founding variables and possible pitfalls. The principlesbehind pediatric LTR differ significantly from those inadult LTR. The smaller size of the pediatric airwaymakes it much less tolerant of a given obstruction than anadult larynx, reducing the margin of error. However,growth works in favor of the pediatric larynx. Fortu­nately, ongoing advances in techniques for airway recon­struction offer new and better options for achieving asuccessful outcome.

A review of pediatric L1R techniques shows an ongo­ing process of development that is unique. Unlike theprogress in many other medical and technological spe­cialties marked by the replacement of the old and obso­lete with the new and improved, progress in LTR comeswith the addition of new techniques to more and morevariations of old techniques. The old techniques remainviable and effective options for many cases of laryngotra­cheal stenosis, while the newer techniques arise from theexperience accumulated with the successes alreadyachieved. Just as specialization has become increasinglyevident in medicine overall, further specialization in LTRwill address specific needs of unique patients and prob­lems.

LASER PROCEDURES

Laser surgery was heralded as a great advance for airwaysurgery, and for minor procedures the laser proved to bea useful tool. Early studies promised increasing use ofthe laser for a multitude of airway problems, includingsevere stenosis. 1 In cases where laser surgery might fail,

From the Department of Pediatric Otolaryngology, Children's Hos­pital Medical Center, Cincinnati, OH.

Address reprint requests to Robin T. Cotton, MD, Department ofPediatric Otolaryngology, Children's Hospital Medical Center, Eilandand Bethesda Ave, Cincinnati, OH 45229.

Copyright © 1992 by W.B. Saunders Company1043-1810/92/0303-0009$05.00/0

it was thought a subsequent open procedure would in noway be hindered by an attempt at laser resection.? How­ever, attempts to use the laser for correcting severestenoses and large hemangiomas resulted in further scar­ring of already obstructed airways, requiring more exten­sive open procedures.i'

Later studies clarified the limited indications for laseruse and the consequences of its improper application.tArytenoidectomy, sometimes performed by laser inadults, is probably better done via an external approachin most pediatric cases. Anterior glottic webs, which al­most always involve the subglottic space as well, shouldbe treated using the Montgomery umbrella keel via ananterior laryngofissure approach. Only small granulo­matous airway lesions, small hemangiomas, and small,thin webs are good candidates for cautious laser proce­dures. Multiple laser procedures increase the amount ofdamage and scarring, causing distortion and ossificationof the cricoid cartilage. Laser failure should lead to con­sideration of an open procedure.

CRICOID FRAMEWORK EXPANSIONWITHOUT GRAFTS

Anterior division of the cricoid cartilage was the first step­in promoting expansion of the laryngotracheal lumen."and it is stilI very effective for isolated anterior subglotticstenosis (Figs 1, 2, 3). The need for division of the pos­terior cricoid (Fig 4) in severe cases of posterior stenosiswas quickly recognized. Grahne was the first to applyRethi's division of the posterior lamina of the cricoid topediatric patients." Scar tissue was excised and laryngealstenting lasted 4 months. Crysdale reforted his use ofthe Rethi technique in children in 1976. That same year,Crysdale and Platt stated, "The key surgical maneuver isthe anterior and posterior division of the cricoid carti­lage.:" Further work was reported by Crysdale and Cre­peau in 1982, using anterior and posterior division of thecricoid cartilage in nine additional children." In 1985,Rinne et al reported the favorable long-term results oftheir initial procedures, firmly establishing the concept ofcricoid framework expansion by anterior and posteriordivision of the cricoid cartilage with long-term stenting. 10

OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY-HEAD AND NECK SURGERY, VOL 3, NO 3 (SEP), 1992: PP 165-172 165

-/

FIGURE 1. Incision in preparation for laryngofissure in atracheotomized patient.

FIGURE 2. Exposure of the larynx and trachea.

FIGURE 3. Anterior division of the cricoidcartilage with division of the tracheal rings to thelevel of the tracheotomy inferiorly, and divisionof the thyroid cartilage extending superiorly to alevel just below the anterior commissure.

FIGURE 4. (Left) View of the posterior wall of the subglottic larynx.(Right) Division of the posterior lamina of the cricoid cartilage.

These methods, along with the variations on anterior di­vision of the cricoid cartilage developed by Evans andTodd.!' continue to be useful.

In cases of subglottic atresia and severe stenoses result­ing from repeated laser or resectoscope procedures orfailed laryngotracheoplasty, anterior and posterior divi­sion of the cricoid cartilage may be inadequate to obtain

166

sufficient enlargement of the airway. Four-quadrant di­vision of the cricoid cartilage (four-quadrant LTR) com­bines anterior laryngotracheal division and posteriorcricoidotomy with bilateral division of the cricoid carti­lage (Fig 5). These additional divisions of the cricoid car­tilage allow particularly severe stenoses with significantlateral components to expand far more than with anterior

PEDIATRIC LARYNGOTRACHEAL RECONSTRUCTION

FIGURE 5. Four quadrant division (anterior, posterior, leftand right lateral) of the cricoid cartilage.

and posterior division alone. This method is comple­mented by the other reconstructive techniques, but onlyrarely includes the use of autogenous costal cartilagegrafts. Special attention must be paid to proper stentingwhen the cricoid cartilage has been divided in fourplaces, because the stability of the cricoid cartilage mustbe maintained during healing. However, continued ad­equate growth of the cricoid cartilage, a subject of greatcontroversy, has not been shown to be adversely affectedin clinical or experimental experience. 12

•13 It has also

been shown that with appropriate attention to the anat­omy, recurrent laryngeal nerve function is not at risk of

being damaged or impaired.!" Four-quadrant LTR wasinitially used in Cincinnati from 1986 to January of 1990,with an overall decannulation rate of approximately 76%in these severe cases.

CRICOID FRAMEWORK EXPANSIONWITH GRAFTS

There have been many variations on the use of grafts tothe airway, including hyoid bone, iliac crest, septal car­tilage, auricular cartilage, autogenous costal cartilage,and composite clavicular bone muscle skin flaps. Severalof these methods have transferred successfully fromadult and experimental use to the pediatric population,with the most popular and versatile approach being theuse of free autogenous costal cartilage grafts. The sur­vival of these grafts has been documented in histologicalstudies of animal and human tissues. 15

There are several basic principles for the optimal use ofcostal cartilage grafts in the airway, To best preserveacceptable vocal function, the anterior commissureshould not be violated if possible (Fig 3). Despite theexcellent survival of autogenous cartilage grafts, some re­sorption does occur. Therefore, the graft used should bethe largest graft possible, especially anteriorly. Thinningof the graft should be kept to a minimum in order tomaintain the rigidity of the graft, and the perichondriumshould be preserved on the luminal surface of the graft(Fig 6). The presence of perichondrium on the outer sur­face of the graft inhibits the transport of nutrients to thetransplanted chondrocytes, resulting in cell death, necro­sis, and resorption of the graft. Flanges left on the carvedgraft help prevent prolapse in the airway lumen. Mono­filament nylon sutures are used to secure grafts firmly inposition. Great emphasis should be placed on minimiz­ing damage to the graft, especially by repeated sutureinsertions. Suture tracts become focal points of granula­tion tissue formation and resorption, causing necrosis ofareas distal to suture tracts.

When only a single graft to the anterior cricoid cartilageis necessary, autogenous costal cartilage provides suffi­cient support for the reconstructed airway so that stent­ing may be avoided.l" Damage to the anterior commis­sure is avoided by limiting the length of the anterior

FIGURE 6. Graft of costalcartilage as used inlaryngotrachealreconstruction.Perichondrium is left intacton the luminal surface ofthe graft to facilitatereepithelialization, andflanges are leftextraluminally to preventprolapse of the graft.

ROBIN T. COTTON 167

FIGURE 7. Placement ofa graft of costal cartilagein the divided posteriorlamina of the cricoidcartilage.

FIGURE 8. View of the posterior graft of costal cartilagesutured in place . The minimum number of sutures necessaryfor stability of the graft is used.

168

laryngofissure; the thyroid cartilage is not divided all theway to the thyroid notch (Fig 3).

As illustrated previously for cricoid framework expan­sion without grafts, the addition of posterior division ofthe cricoid makes it possible to achieve greater expansionof the lumen in cases of severe stenosis, because the pos­terior glottis is the respiratory airway, The divided pos­terior lamina of the cricoid cartilage may be maintained inposition by the placement of a posterior autogenous cos­tal cartilage graftI7 (Figs 7, 8). A period of stenting isrequired for sufficient healing to occur before the recon­structed airway regains structural stability.

Until recently, grafts to the posterior cricoid cartilagewere considered by some to be less effective or detrimen­tal when compared with anterior grafts. Experimentalobservations now show that posterior grafts fare at leastas well as their anterior counterparts in a controlled studybased on the amount of graft resorption. A clinical studyof posterior grafts and their relationships to voice quality,exercise tolerance, and sleep patterns showed postoper­ative improvement in all three categories for most pa­tients. IS Voice quality is a topic of particular concern, butby strict adherence to the preservation of the anteriorcommissure, voice quality can be reasonable even afterextensive reconstruction procedures.

STENTING

Stenting materials and techniques continue to be im­proved. New materials and new conformations for betterstents offer promising alternatives for the near future.Ten years of experience with rigid Aboulker stents (Cot-

PEDIATRIC LARYNGOTRACHEAL RECONSTRUCTION

ton-Lorenz; Walter Lorenz Surgical Instruments, Jackson­ville, FL) has shown good results in both full-length (Fig9) and above-stoma (Fig 10) configurations. Enhance­ments to both the design of rigid stents and techniquesfor modifying them in the operating room have decreasedthe incidence of granulation tissue at the base of the stentin the above-stoma configuration and have reduced therisk of breakage of the stents in the full-length configu­ration.

The duration of stenting has decreased since its initialuse in pediatric LTR. In cases of anterior and posteriordivision of the cricoid cartilage, stenting is limited to 6weeks. Longer stenting, on the order of 4 to 6 months, isnow limited to those cases where the cricoid cartilage issignificantly ossified, lacks rigidity, or has been dividedbilaterally in addition to anterior and posterior divisions(four-quadrant LTR). The Montgomery T-tube (BostonMedical Products, Waltham, MA) with the interlockingretainer flange on the exterior limb is also used for long­term stenting. The relatively novel use of endotrachealtubes for short-term stenting has made possible the "sin­gle-stage laryngotracheoplasty" in carefully selected pa­tients.

INNOVATIONS IN LTR

Two techniques worthy of special attention are four­quadrant LTR, previously described, and single-stage

laryngotracheoplasty with endotracheal tube stenting(single-stage LTR). In keeping with the continued devel­opment of LTR, these techniques draw on past methodsand experience, in each case taking them slightly furthertoward optimal treatment.

LTR is considered to have five basic stages19: (1) eval­uation and characterization of the stenotic lesion (Cottonstenosis grades 1 to 420 and endotracheal tube sizing); (2)expansion of the lumen, with concomitant preservationof function; (3) stabilization of the enlarged lumen frame­work; (4) healing of the surgical site; and (5) decannula­tion. Single-stage LTR compresses stages 3, 4, and 5 ofthe LTR process into a brief period of intubation.

Single-stage LTR has as its main component the use ofan endotracheal tube for a brief period of stenting. Thisfollows the reconstructive procedure using standard LTRtechniques, with the option of additional attention to thetracheotomy site. Single-stage procedures were first con­ceived and tried as early as 1975, but the lack of today'slevel of intensive care support limited single-stage LTRuntil 1986. Adequate support from the intensive careunit is a vital component for the success of this technique.

Most single-stage LTR procedures use anterior divisionof the cricoid cartilage and insertion of an anterior costalcartilage graft. Stenting consists of 3 to 7 days of intuba­tion under intense supervision in the intensive care unit.If possible, steroids are avoided in single-stage LTR tominimize the risk of resorption of the cartilage graft.

In procedures requiring posterior division of the cricoid

---------------------~

FIGURE 11. Interlockinggrafts of costal cartilage supportingboth the anteriorly divided cricoid cartilageand the formerstoma site.

FIGURE 9. Full-length configurationof the Cotton-Lorenz stent withmetal tracheotomy tube.

ROBIN T. COnON

FIGURE 10. Above-stoma configurationof the Cotton-Lorenz stent with typicalpediatric tracheotomy tube in place.

169

1

FIGURE 12. Preparation for exposure of the larynx andtrachea before laryngotracheoplasty for congenitallong-segment tracheal stenosis.

cartilage, with or without a posterior graft, the period ofintubation is extended to 12 to 15 days, due to the in­creased instability of the anteriorly and posteriorly di­vided cricoid cartilage. Even with a cartilage graft to theposterior cricoid cartilage, adequate airway expansionwill not likely be achieved for a grade 4, or complete,stenosis by the single-stage technique.

Extra cartilaginous graft material can be used to but­tress a collapsing or obstructive suprastomal region dur­ing the LTR procedure (Fig 11). The additional graft isplaced horizontally across the stoma site and interlockswith the regular anterior cartilage graft.

Patients without preoperative tracheotomy may avoidthe need for tracheotomy altogether when properly cho­sen for single-stage LTR. Cases of severe subglottic andcircumferential stenosis are better treated with other tech­niques, because the period of intubation may not providesufficient stenting. The compressed nature of single­stage LTR requires that patients have normal pulmonaryfunction, and that there are no coexistent medical prob­lems that require a tracheotomy. Single-stage LTR pro­cedures in Cincinnati analyzed from 1985 to July of 1990showed an overall decannulation rate of 83%.

Congenital long-segment tracheal stenosis due to com­plete rings of cartilage is an extremely difficult problemthat is often best addressed with single-stage LTR donewith the patient on cardiopulmonary bypass (Fig 12).A castellated anterior tracheal incision is made to expandthe tracheal lumen (Fig 13), and the complete trachealrings are divided posteriorly (Figs 14, 15). Expansion is

FIGURE 13. Castellatedanterior incision throughcomplete tracheal rings.

FIGURE 14. View of theposterior wall of the stenotictrachea through thecastellated anterior incision.

FIGURE 15. Division of theposterior tracheal wallthrough complete trachealrings.

170 PEDIATRIC LARYNGOTRACHEAL RECONSTRUCTION

maintained by an indwelling endotracheal tube (Fig 16).Though the castellations are not adequately opposable forsuturing together, they will provide adequate support fora pericardial patch placed over the castellated incision.The castellations prevent sagging of the pericardial graftduring inspiration. If necessary, an anterior cricoid splitmay be performed to decompress the larynx and avoidfurther injury to the laryngotracheal complex during theperiod of intubation. An endotracheal tube is left in placefor 3 to 4 weeks.

RESECTION AND ANASTOMOSIS

This technique is one variation of LTR that has been lim­ited in its application primarily to adult patients. In pe­diatric patients, stenosis almost always extends into thelarynx, making it difficult to define a clear superior resec­tion margin. In some pediatric cases of isolated trachealstenosis, resection with end-to-end anastomosis is an al­ternative to conventional LTR techniques.

RELATED CARE ISSUES

Preoperative assessment of pulmonary function becomesincreasingly important as the duration of stenting de­creases, and especially in single-stage LTR, where rein­tubation may be difficult and the tracheotomy site is un­available if needed. Unfortunately, objective pulmonaryfunction data are difficult to obtain in young patients,leaving the surgeon dependent on close cooperation withneonatologists and pulmonologists for this information.LTR should always be postponed until lung developmentis sufficient for spontaneous respiration with 35% or lesssupplemental oxygen.

Gastroesophageal reflux is recognized as an importantfactor in the resolution of subglottic stenosis, and it mustbe controlled or alleviated before LTR is attempted. Pa­tients identified with significant reflux should be reeval­uated whileOil medical treatment. If reflux persists, medicalor surgical management may be required before LTR canbe performed. It is important that gastric acid not im­pinge on the subglottic area to allow proper healing of theoperative site to occur. Antacid medication may be usedpreoperatively and postoperatively to control subclinicalreflux.

The preservation or restoration of vocal function hasnot been the primary concern in LTR, where the estab­lishment of an adequate airway is the first priority. How­ever, with improved results from LTR in general, it is nolonger reasonable to minimize this aspect of the recon­structive process. In sufficiently developed patients, pre­operative assessment of vocal function should be per­formed in cooperation with a speech pathologist. Theassessment should include acoustic, functional, and sub­jective tests, in addition to stroboscopic examinationwhen possible. Postoperatively, following stent re­moval, reevaluation should be performed. Adequate re­ferrals to speech pathology must be made to ensure re­habilitative and developmental therapy where required.

CONSERVATIVE TREATMENT

The role of the laser for the resection of small congenitalsubglottic hemangiomas may obscure the fact that most

ROBIN T. COnON

FIGURE 16. (Left) Endotracheal tube in place to maintain theexpansion of the reconstructed trachea. (Right) Pericardialpatch in place over the anterior castellated incision and theindwelling endotracheal tube.

lesions of this nature involute within the first 2 years oflife. In cases where extensive resection would be re­quired to remove the lesion, a tracheotomy for airwaymaintenance with meticulous home care may yield thebest long-term result: an unscarred, normal airway." Incases of firm, fibrotic stenoses, the role of conservativewait-and-see strategies remains controversial. To besure, growth works in favor of the young pediatric LTRpatient, and occasionally results in airway developmentsufficient to alleviate minor problems. Unfortunately,growth is rarely ample to circumvent the need for so~eform of surgical intervention. Chevalier Jackson noted 10

1932:

It is distressing to note that insistence upon the great aid ob­tained in the treatment of laryngeal stenosis in children by thegrowth of the larynx has been so misconstrued as to merge intothe advice so often ill-advisedly and casually given in variousdiseases of childhood, namely, 'He will outgrow it: It cannotbe too emphatically stated that children never outgrow stenosisof the larynx.

Prompt surgical management is further favored ~y stud­ies indicating that the presence of normal bactenal fl~ra

associated with tracheotomy may exacerbate or contrib­ute to the development of greater stenosis of the subglot­tic region. 21 Additionally, the presence of a stenosis atthe level of the cricoid cartilaqe may also restrict the nor­mal growth of that structure. 2,23

171

Obviously, there are limits to early intervention sec­ondary to the age and developmental status of the patientand the stenosis. A 4-month-old baby with gastroesoph­ageal reflux and a soft, dilatable stenosis is hardly a can­didate for a major reconstructive procedure. The lungsmust be developed enough to provide reliable reservefunction postoperatively, the stenosis should consist ofmature fibrous tissue, and all coexisting medical condi­tions, especially reflux and upper respiratory infection,should be well-controlled before proceeding with LTRsurgery.

CONCLUSION

The state of the art in pediatric LTR is a dynamic state,constantly changing with new enhancements in tech­nique and as new clinical needs arise. The future maysee a change in the patient population requiring LTR, asthe state of the art of intubation is advanced, with thecontributions of preventive measures from surfactanttherapy and ventilatory support of younger and youngerinfants. For the present, it is important that every optionbe considered and appropriately screened for applicationin a particular case; no single method holds the key tosuccessful LTR. Experience and possible approaches tothis consistently difficult pediatric problem continue togrow in scope and variety.

ACKNOWLEDGMENTSThe author wishes to express his appreciation to JenniferWalker, medical illustrator, and David M. O'Connor, researchcoordinator, for their contributions to the preparation of thismanuscript.

REFERENCES

1. Healy GB: An experimental model for the endoscopic correction ofsubglottic stenosis with clinical applications. Laryngoscope 92:1103­1115, 1982

2. Friedman EM, Healy GB, McGill TJ: Carbon dioxide laser manage­ment of subglottic and tracheal stenosis. Review. Otolaryngol ClinNorth Am 16:871-877, 1983

3. Cotton RT, Tewfik TL: Laryngeal stenosis following carbon dioxidelaser in subglottic hemangioma. Report of three cases. Ann OtolRhinol Laryngol 94:494-497, 1985

4. Duncavage JA, Ossoff RH, Toohill RJ: Carbon dioxide laser man­agement of laryngeal stenosis. Ann Otol Rhinol Laryngol 94:565­569, 1985

172

5. Cotton RT, Myer CM, Bratcher GO, et al: Anterior cricoid split,1977-1987. Arch Otolaryngol Head Neck Surg 114:1300-1302, 1988

6. Grahne B: Operative treatment of severe chronic traumatic laryn­geal stenosis in infants up to three years old. Acta Otolaryngol(Stockh) 72:134-137, 1971

7. Crysdale WS: Extended laryngofissure in the management of sub­glottic stenosis in the young child: A preliminary report. J Otolaryn­gol 5:479-486, 1976

8. Crysdale WS, Platt LJ: Division of posterior cricoid plate in youngchildren with subglottic stenosis. Laryngoscope 86:1451-1458, 1976

9. Crysdale WS, Crepeau J: Surgical correction of subglottic stenosis inchildren. J Otolaryngol 11:209-213, 1982

10. Rinne J, Grahne B, Sovijarvi AR: Long-term results after surgicaltreatment of laryngeal stenosis in small children. Int J PediatrOtorhinolaryngol 10:213-220, 1985

11. Evans JNG, Todd GB: Laryngo-tracheoplasty. J Laryngol Otol 88:589-597, 1974

12. Silver F, Myer CM III, Cotton RT: Lateral division of the rabbitcricoid cartilage: Its effect on cartilage growth. Presented at theAmerican Academy of Otolaryngology-Head and Neck Surgery,Annual Meeting, September 1991, Otolaryngol Head Neck Surg

13. Cotton RT, Mortelliti AJ, Myer CM III:Four quadrant division of thecricoid cartilage in laryngotracheal reconstruction. Presented at theAmerican Society of Pediatric Otolaryngology, Annual Meeting,May 1991, Waikoloa, Hawaii

14. Drake AF, Contencin P, Narcy F, et al: Lateral cricoid cuts as anadjunctive measure to enlarge the stenotic subglottic airway: Ananatomic study. Int J Pediatr OtorhinolaryngoI18:129-137, 1989

15. Zalzal GH, Cotton RT, McAdams AJ: The survival of costal cartilagegraft in laryngotracheal reconstruction. Otolaryngol Head NeckSurg 94:204-211, 1986

16. Cotton RT:Management of subglottic stenosis in infancy and child­hood. Ann Otol Rhinol Laryngol 87:649-657, 1978

17. Cotton RT, Evans IN: Laryngotracheal reconstruction in children.Five-year follow-up. Ann Otol Rhinol Laryngol 90:516-520, 1981

18. Cotton RT: The problem of pediatric laryngotracheal stenosis: Aclinical and experimental study on the efficacy of autogenous carti­laginous grafts placed between the vertically divided halves of theposterior lamina of the cricoid cartilage. Laryngoscope 101:1-34,1991 (suppl 56)

19. Cotton RT, Myer CM III, O'Connor OM: Innovations in pediatriclaryngotracheal reconstruction. J Pediatr Surg 27:196-200, 1992

20. Cotton RT, Gray SO, Miller RP: Update of the Cincinnati experiencein pediatric laryngotracheal reconstruction. Laryngoscope 99:1111­1116, 1989

21. Sasaki CT, Horiuchi M, Koss N: Tracheostomy-related subglotticstenosis: Bacteriologic pathogenesis. Laryngoscope 89:857-865, 1979

22. Adriaansen FCPM, Verwoerd-Verhoef HL, van der Heul RO, et al:Morphometric study of the growth of the subglottis after endola­ryngealtrauma. Int J Pediatr Otolaryngol 12:217-226, 1986

23. Adriaansen FCPM, Verwoerd-Verhoef HL, van der Heul RO, et al:A histologic study of the growth of the subglottis after endolaryn­gealtrauma. Int J Pediatr Otolaryngol 12:205-215, 1986

PEDIATRIC LARYNGOTRACHEAL RECONSTRUCTiON