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Histopathology Holinger et al (1976b) emphasized that the more accurate the histopathologic diagnosis of subglottic stenosis, the more precise and appropriate will be the treatment. The most common abnormality is generalized circumferential stenosis of the cricoid cartilage, so that the subglottic diameter is small. However, the lumen may be eccentric, and the abnormal shape of the cricoid cartilage may be associated with a large anterior lamina, an oval or elliptic shape, a large posterior lamina, or generalized thickening. A submucosal (occult) cleft or a trapped first tracheal ring (Tucker, 1982; Tucker et al, 1979) is a rare deformity. Soft subglottic stenoses of a congenital nature may be caused by submucosal mucinous gland hyperplasia and must be distinguished from a congenital subglottic hemangioma or, less commonly, from ductal cystic disease and from acquired soft tissue subglottic narrowing caused by submucosal fibrosis and/or granulation tissue. The latter may be acquired and caused by endotracheal intubation, a complication more likely to occur in the patient who has an underlying congenital subglottic stenosis. Diagnostic evaluation Typical findings. The manifestations of congenital subglottic stenosis usually occur in the first few weeks or months of life and are not always evident at birth or in the neonatal period. Stridor is the most common feature, followed by respiratory distress, a harsh "croupy" barking cough, or a hoarse cry. The condition affects males twice as often as females. Having associated congenital abnormalities of the upper respiratory tract or other organs is not uncommon. Clinically, congenital subglottic stenosis may present in the following ways: 1. "Subacute", or persistent, croup, in which the stridor lasts for 1 to 3 weeks (whereas the usual attack of acute viral laryngotracheitis lasts 1 to 3 days). 2. Recurrent atypical croup, with each attack persisting for longer than usual. 3. Difficulty introducing an endotracheal anesthetic tube of average size. Narrowing of the subglottic region is detected when the child is being anesthetized for some unrelated surgical condition. 4. Decannulation difficulty after tracheotomy or extubation difficulty after prolonged intubation. A tight endotracheal tube without a leak of gas around the subglottic region may cause reactive mucosal edema after the tube is removed. Stridor and a croupy cough may occur minutes or hours after extubation. Congenital subglottic stenosis is often the underlying lesion in patients in whom one of the following is true: (1) difficulty removing an endotracheal tube exists after an ill-managed, prolonged intubation; or (2) tracheotomy tube extubation fails after the tracheotomy has been performed for prolonged or recurrent croup. 26
Endoscopic findings. A lateral airway radiographic study usually shows the congenital subglottic stenosis clearly (Fig. 99-21). However, the definitive diagnosis is made at endoscopy; the diameter of the subglottic region is assessed carefully and gently, especially if the airway is marginal. The usual finding is an isolated circumferential subglottic stenosis, the diameter of which is then measured. The outside diameter of a bronchoscope or an endotracheal tube that passes comfortably through the subglottic region represents the internal diameter of the cricoid, which is therefore calibrated and recorded for future reference. The endoscopic findings are less severe than those in patients with acquired subglottic stenosis. Occasionally diagnostic endoscopy results in minimal but significant mucosal swelling in the subglottic region, caused by the trauma of excessive manipulation, the passage of too large a bronchoscope, or repeated manipulation. This is more significant when there is a preexisting subglottic stenosis. Subglottic edema occurs within the limits of the inexpansible cricoid cartilage in the immediate postendoscopic period. There may be croupy cough, stridor, and increasing airway obstruction. Careful technique should reduce the incidence of this complication to an absolute minimum. Management Management is based on the knowledge that children outgrow congenital subglottic stenosis. Most cases produce few or minimal symptoms, and no definitive treatment is required unless acute inflammation or trauma from intubation or endoscopy precipitates serious obstruction. However, when a major degree of congenital subglottic stenosis exists or when acquired fibrous tissue granulations and edema produce a serious obstruction, a tracheotomy may be require. Small patients with a stenosis severe enough to require a tracheotomy may require repeated endoscopic examination over months or years, awaiting sufficient relative improvement of the subglottic diameter to allow decannulation. This conservative management prevents the potential complications of external laryngeal surgery in the infant. On the other hand, Cotton and Evans (1981), among others, have advocated a more aggressive approach by laryngotracheal surgical reconstruction to obtain a lumen large enough to permid decannulation. Repeated "dilation treatment" of hard cartilaginous stenosis is not successful, and ill-judged forced "dilations" inevitably cause further trauma and scarring. Laser resection has a limited application and must be restricted to treatment of the soft tissue swelling in selected cases where the stenosis is less than 5 mm thick. There is no uniform management of subglottic stenosis and no universally successful endoscopic or external surgical technique. The tracheotomy tube usually should be worn for an extended period of time to allow the cartilaginous stenosis to grow along with the child's general rate of growth until the problem is overcome. Decannulation is usually possible even in difficult cases by the age of 3 to 4 years. Laryngeal hemangioma Hemangiomas are congenital malformations that form from mesodermal rests of vasoformative tissue. In most anatomic sites they can be managed conservatively, but narrowing of the airway is an exception. Congenital hemangioma in the larynx usually occurs in the subglottic region, developing in the submucosa and following a typical growth pattern, with increased size usually causing symptoms within the first 8 weeks or so of life. A review of autopsy cases (Brodsky et al, 1983) showed that the lesion sometimes extended into the 27
Page 1 and 2: Chapter 99: Congenital Disorders of
Page 3 and 4: History of Clinical Features Signif
Page 5 and 6: example in laryngomalacia, may vibr
Page 7 and 8: --> Tracheal compression --> Hemang
Page 9 and 10: The cri-du-chat syndrome (Ward et a
Page 11 and 12: In selected cases contrast tracheob
Page 13 and 14: Laryngoscopy with telescopes gives
Page 15 and 16: tracheotomy because of the relative
Page 17 and 18: Cyanotic attacks are so uncommon th
Page 19 and 20: (Fig. 99-11). A lateral saccular cy
Page 21 and 22: A tracheotomy is almost always nece
Page 23 and 24: Congenital interarytenoid web is a
Page 25: supraglottic changes similar to tho
Page 29: combined with external radiation ha

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