Volume 1, Issue 4 , Pages 261-266, December 2006
Relapsing diffuse idiopathic tracheal stenosis in a child: Dilemmas in management
Article Outline
Summary
Subglottic stenosis is a common presentation of biphasic stridor in young children, however a rarer cause of biphasic stridor is tracheal stenosis. Causes of acquired non-neoplastic diffuse tracheal stenosis include Wegener's granulomatosis, sarcoidosis, TB, relapsing polychondritis, and thermal trauma. However, on occasions no pathological process or agent can be identified as the aetiological factor. In such instances this is defined as idiopathic tracheal stenosis. In this paper, we present the causes of diffuse tracheal stenosis, and propose a sensible pathway for management where a causative agent cannot be elucidated including the use of balloon dilatation within an endotracheal tube.
Keywords: Idiopathic, Trachea, Stenosis, Management, Balloon dilation, Endotracheal tube
1. Introduction
Acquired, non-neoplastic, diffuse tracheal stenosis is a rare cause of biphasic stridor in children. The common causative agents include: systemic or regional wegners granulomatosis (WG), relapsing polychondritis (RP), tuberculosis (TB) sarcoidosis, and inhalational thermal trauma [1]. On occasions no inflammatory, infective or autoimmune cause cannot be identified leading to the diagnosis of idiopathic diffuse tracheal stenosis. Only two cases have been described in modern literature in children [2], [3]. In this case study we present such a patient together with a proposed management plan and a novel approach to dilating the stenotic portion of the trachea using a balloon within an endotracheal tube to protect friable mucosa from further sheering forces.
2. Case report
An 8-year-old female presented to the general paediatric physicians at a district general hospital, with an 8-month history of cough and dyspnoea. A mild upper respiratory tract infection preceded these symptoms. A diagnosis of mild asthma was made and therapy commenced with a salbutamol inhaler. However, there was minimal change in shortness of breath, and the cough persisted. At a follow-up visit 2 weeks later, an inspiratory wheeze was noticed on chest auscultation. A local ENT opinion was sought after which, an urgent direct bronchoscopy under general anaesthetic was planned to exclude causes of an upper airway obstruction or a foreign-body in the airway. At the time of the direct bronchoscopy, an unusual ‘subglottic’ stenosis was identified. The degree of circumferential stenosis, length or characteristics of the stenotic segment were not recorded. The patient was transferred urgently to our unit for further assessment and management.
A detailed history failed to provide any further useful information. The patient was previously fit and well, with no past history of medical problems, upper aero digestive tract trauma or prior endotracheal intubation. An overnight oximetry study failed to reveal any significant periods of desaturation or apnoea. A direct laryngotracheobronchoscopy (DLTB) under general anaesthesia was scheduled.
Following nasopharyngeal intubation and anaesthesia, and whilst breathing spontaneously, a DLTB was performed using a size 4 Hopkins Rod (Karl Storz, Tuttlingen Germany). This identified a 1.8
cm long, granular tracheal stenosis 2cm below the subglottis (Fig. 1). The airway had been narrowed by more than 50% to 4.8mm. A biopsy was not performed at this stage as it may have caused further mucosal damage and exacerbated the stenotic problem.
Fig. 1.
Original view of trachea showing stenotic segment.
The stenotic segment was sequentially dilated using first a size 4 portex endotracheal tube (Smiths Medical Group, Hythe, Kent, United Kingdom), to a maximum of size 6 (outer diameter 8.2mm). This produced a very satisfactory lumen at completion of dilatation (Fig. 2). Bacteriology swabs were taken from the stenotic segment. A sample of blood was taken to measure the full blood count and for an autoimmune screen, that included pANCA, cANCA, ANA, and ESR. A CT scan of the mediastinum was organized. A further endoscopic evaluation was planned after 2 weeks. The child was discharged with oral dexamethasone 2mg bd and co-amoxiclav suspension (250/62) 5ml tds for 1 week.
Fig. 2.
Post dilatation of stenotic segment using Endotracheal tubes showing a good result but mucosal trauma.
The full blood count was normal. The autoimmune screen was negative. Bacteriology swabs isolated scanty group A beta-haemolytic streptococci. No acid-fast bacilli were detected. The CT scan of the mediastinum showed a diffuse stenosis of the trachea, without extra-tracheal pathology or lymphadenopathy. The patient remained asymptomatic. A repeat DLTB 2 weeks later showed a stable, but very unusual trabeculated fibrotic stenosis of the trachea (Fig. 3). The tracheal diameter was approximately 8.2mm at this time.
Fig. 3.
Two weeks post dilatation, trabeculated stenosis eveident and starting to re-stenose.
Unfortunately, over the following 4 weeks the patient developed increasing dyspnoea, particularly on exertion. Repeat DLTB showed that the trachea had narrowed to about 5.2mm, which represented a 40% reduction in diameter (Fig. 4). There was no evidence of infection or granulomatous lesions. The patient was commenced on prednisolone 5mg od for 2 weeks. Another DLTB was scheduled after 4 weeks.
Fig. 4.
Severe trabeculated stenosis of the trachea causing significant airway narrowing.
Before the scheduled DLTB the child deteriorated with increasing biphasic stridor and an overnight pulse oximetry revealing 21 desaturations below 89%. An urgent DLTB showed that there had been no increase in the length of the stenotic segment, but that the tracheal diameter had decreased to 4.8mm. The stenotic segment was sequentially dilated again to 6.2mm using sizes 3.5, 4, and 4.5 portex endotracheal tubes followed by dilatation to 7mm using a valvotomy balloon (Blue Max Boston Scientific, Natick Massachusetts USA) within a size 5 portex endotracheal tube coated in triamcinolone ointment (Bristol-Myers Squibb, New York, USA) (Fig. 5, Fig. 6).
Fig. 5.
Fusiform dilatation of endotracheal tube with valvotomy balloon inflated to operating pressure.
Fig. 6.
Close up view showing fusiform dilatation of the ETT.
The balloon was slowly inflated using normal saline to 8atm, and held at this pressure for 1min. The patient remained well in the postoperative period without further desaturations. She was discharged with prednisolone 10mg od for 5 weeks.
At this time, a further autoimmune screen was performed. Once again, pANCA, cANCA, serum ACE levels and functional antibodies were within normal limits.
A repeat DLTB, 4 weeks later was performed and a small biopsy was taken from the proximal aspect of the lesion. The lesion was again sequentially dilated using firstly a size 8mm, followed by a size 10mm valvotomy balloon (Fig. 7).
Fig. 7.
Dilatation of stenotic segment showing minimal mucosal trauma with excellent result.
High-dose postoperative intravenous methyl-prednisolone 600mg od for 3 days was commenced. The patient was discharged after this time with prednisolone 30mg od and a short course of ranitidine 75mg bd (1 month).
Histology has not identified evidence of granulomatous or vasculitic lesions. It has shown only chronic inflammation. Despite developing cushingoid features, the patient has remained asymptomatic for 6 months. Two further DLTBs have demonstrated that the stenotic segment has remained stable (Fig. 8). The airway lumen is unchanged at 7mm. The steroid therapy has been tapered and stopped. Clinically, the child has a normal exercise tolerance, and has not developed any new symptoms. We have been unable to identify an aetiological cause for this lesion, despite serial investigations that have included a biopsy. Accordingly, a diagnosis of idiopathic diffuse tracheal stenosis has been made.
Fig. 8.
Stable lesion with minimal re-occurrence of stenosis 2 months post-dilatation and steroid treatment.
3. Discussion
Before the diagnosis of diffuse idiopathic tracheal stenosis can be made the most common aetiologies of Wegners granulomatosis, relapsing polychondritis, TB, sarcoidosis, thermal trauma and histoplasmosis need to be excluded [3]. This leaves the clinician with a two-fold problem namely maintenance and protection of the airway whilst trying to identify a causative agent.
Relapsing polychondritis (RP) is a rare condition affecting predominantly cartilaginous structures of the ear, nose and laryngobronchial tree. Aetiology is largely unknown and the pathogenesis is thought to be autoimmune with the presence of antigen-antibody complexes’ in affected cartilage and cellular and humoral response to type II cartilage. A 40–56% of patients present with dyspnoea cough and wheeze with diffuse involvement of the laryngobronchial tree [4].
Wegners granulomatosis is a chronic necrotizing granulomatous disease affecting the entire upper respiratory tract, small vessels and kidneys. It is described as regional when only affecting the sinopulmonary tract. The pathogenesis is unknown. Diagnosis consists of raised inflammatory markers, positive cANCA together with a positive biopsy of the infected area showing vasculitis or necrotizing granulomas [5].
Sarcoidosis is a systemic granulomatous disease of unknown aetiology rarely affecting children. It is diagnosed primarily on a histological basis by demonstrating non-caseating granulomata in affected tissue after excluding other causes for granulomatous disease [6].
Tuberculosis is a chronic caseating granulomatous disease affecting practically any system in the body. The main causative organism is Mycobacterium tuberculosis. Diagnosis is achieved by identifying acid-fast bacilli from tissue biopsies, sputa samples or culture samples.
Histoplasmosis is caused by the inhalation of Histoplasmosis capsulatum a dimorphic soil fungus endemic in soil in warm countries with large migratory bird populations. This can cause a flu-like illness but in immunocompramised individuals can cause diffuse pulmonary and systemic disease. It is best diagnosed using cultures taken from infected sites, serological tests or histological examinations from tissue biopsy that show large caseating granulomatous lesions with demonstratable yeast using Gomori methenamine silver (GMS) or periodic acid Schiff (PAS) test [7].
Extensive autoimmune screens, cultures, biopsies and routine blood tests were all normal over a period of 5 months leading to the diagnosis of idiopathic tracheal stenosis.
This lesion presented a complex airway management problem [8]. At the height of the tracheal narrowing the patient was dyspnoeic at rest but fortunately did not have acute stridor or significant desaturations necessitating the insertion of a tracheostomy tube.
It is recognized that although safe guarding the airway is of paramount importance, a tracheostomy should be avoided, if possible, when tracheal reconstruction is being considered as fibrotic tissue makes the mobilization of the trachea difficult and localized bacterial infection around the tracheostomy site could cause anastomotic breakdown [9].
Initial biopsy of the area was also avoided in order to avoid further traumatizing the damaged mucosa and increasing the degree of stenosis.
In order to provide the patient with a stable airway yet avoid an invasive procedure we decided to dilate the stenosis using endotracheal tubes. This worked initially, but we were concerned that the vertical sheering forces applied to the mucosa during the dilatation might provoked fibroblastic activity and caused an increase in the stenotic area.
To minimize mucosal trauma a novel approach was adopted to dilate the trachea. The maximum area of stenosis was carefully sized using a rigid Hopkins rod and ETT and the correct sized ETT was gently placed through the stenotic area coated in a steroid/antibiotic ointment. Thereafter increasing sized valvotomy balloons were placed within the ETT and inflated to their maximum operational pressure at 37°C resulting in dilatation without vertical shearing forces. Table 1 demonstrates the increase in circumferences of ETT using a 7 and 10mm valvotomy balloon.
Table 1. Change in the outer circumference of endotracheal tubes at 37°C with valvotomy balloon inflated to maximum working pressure for 1min
| Size of Portex endotracheal tube (ETT) | Outer diameter (od) of ETT | Circumference (circ.) of ETT | 7mm valvotomy balloon od | Circ. of ETT post dilatation of 7mm valvotomy balloon | 10mm valvotomy balloon od | Circ. of ETT post dilatation of 10mm valvotomy balloon |
|---|---|---|---|---|---|---|
| 4.5 | 6.2 | 19.4 | 7.96 | 25 | 8.0 | 25 |
| 5.0 | 6.9 | 21.66 | 8.1 | 25.5 | 8.3 | 26 |
| 5.5 | 7.6 | 23.9 | 8.6 | 27 | 9.2 | 29 |
| 6.0 | 8.2 | 25.7 | 8.9 | 28 | 10.2 | 32 |
| 6.5 | 8.9 | 28 | 10.2 | 32 | 10.7 | 33.5 |
Although balloon dilatation of the tracheal lumen is an accepted method of treatment [10] it may also lead to tearing of the mucosa due to the rapid expansion of the pre-determined balloon diameter at the operational pressure. The aim of using the balloon within the ETT was to control the final expansion diameter thereby limiting the risk of the mucosal damage. This method has not been described in modern English literature.
This procedure was repeated again, 1 month later with a biopsy with excellent results.
In consultation with the paediatric rheumatologist it was decided to use high dose steroids to prevent progression of a possible inflammatory or autoimmune disease whilst awaiting final cultures, serology and histology results.
This approach of sequential dilatation of the stenotic segment using this method together with high dose steroid treatment allowed us to maintain the airway conservatively. The diagnosis by exclusion was diffuse idiopathic tracheal stenosis.
Should the patient's airway failed to remain stable we would have considered excising the diseased segment of trachea and performing a slide a slide tracheoplasty or end-to-end anastomosis [11].
4. Conclusion
Idiopathic tracheal stenosis is a rare and complex problem to manage. The surgeon has no definitive diagnosis and therefore does not know how the tracheal mucosa will respond to conservative management and whether the lesion will appear elsewhere in the tracheal mucosa. The problem is compounded by the necessity to protect the patient's airway whilst trying to avoid a tracheostomy because of the effects on tracheal surgery.
In this case the a traumatic dilatation of the tracheal lumen using a valvotomy balloon catheter within an ETT to provide gentle, uniform pressure as well as high dose steroids provided an excellent conservative approach whilst safe guarding the airway during diagnosis and subsequent treatment.
Despite this approach the safety of the child's airway is of paramount importance and has to be assessed regularly to determine the degree and progression of stenosis and management varied accordingly.
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PII: S1871-4048(06)00045-1
doi:10.1016/j.pedex.2006.04.001
© 2006 Published by Elsevier Inc.
Volume 1, Issue 4 , Pages 261-266, December 2006
