Canine model of subglottic stenosis secondary to prolonged endotracheal intubation

Acquired subglottic stenosis is usually a consequence of prolonged endotracheal intubation. The present study describes a canine model of subglottic stenosis which is congruent with the known and suspected pathogenesis of the disease in man. Eighteen young pups (Canis familiaris) were used. A modified cuffed endotracheal tube was placed within the subglottis and secured by inflating the cuff. The capillary tube supplying the cuff was sealed and cut so as to lie below the epiglottis. Three animals died of tracheal rupture or collapse prior to or on the thirteenth day following intubation. In the remaining animals, the cuffed tube was removed and the subglottis was examined. All exhibited ulcerations and exuberant polyploid granulations at the level of the subglottis and trachea. A 4 mm uncuffed endotracheal tube was introduced and secured within the subglottis and trachea of a number of the pups to provide an airway. After a 3-week period, the tube was removed and the dogs were sacrificed. Examination of the specimens showed various degrees of “hard” cicatricial stenosis of the subglottis and trachea. Histologic studies showed destruction of the cartilage with replacement by scar tissue and partial epithelialization. This model may be useful to investigations of the prevention and treatment of the disease.     

Management of synchronous subglottic stenosis and bronchial stenosis with a modified endotracheal tube

We present the case of a tracheostomy tube-dependent 6-month-old infant with synchronous airway lesions, including grade III subglottic stenosis and left main bronchomalacia with recurrence of granulation tissue and stenosis. Because the infant was at high risk for complications from the tracheostomy tube, decannulation was the desired outcome. The airway lesions were managed by single-stage laryngotracheal reconstruction and short-term stenting of the subglottis and left main bronchus. The greatest challenge was management of progressive stenosis caused by recurrence of granulation tissue in the left main bronchus. A novel modification of a soft silicone elastic endotracheal tube was devised to provide continued ventilation of both lungs while the corrected lesions healed. The role for this type of stent and the benefits and difficulties associated with its use are discussed.     

喉声门型癌声门下受侵与外科治疗选择

目的探讨喉声门型癌声门下受侵合适的外科治疗方式。方法回顾性分析102例喉声门型癌声门下受侵患者的局部声门下受侵范围及所行手术方式。根据受侵范围,将患者分为两组。第一组为声门下受侵在声带游离缘下0.5cm～1.0cm之间,第二组为声门下受侵达声带游离缘下1.0cm以上。分析比较两组患者的不同手术方式的3年无瘤生存率及淋巴结转移率。结果102例喉声门型癌声门下受侵患者总的3年无瘤生存率为58.8%。两组的生存率分别为66.7%(22/33)、55.1%(38/69)。第一组病例喉全切除术、喉近全切除术、喉部分切除术的生存率分别为60.0%(6/10)、2/2、66.7%(14/21);第二组病例喉全切除术、喉近全切除术、喉部分切除术的生存率分别为58.7%(27/46)、50.0%(6/12)、45.5%(5/11)。本资料两组患者的淋巴结阳性率分别为6.1%(2/33)、15.9%(11/69)。淋巴结阳性与阴性患者的生存率分别为23.1%(3/13)、64.0%(57/89)。结论声门下受侵是影响喉声门型癌预后的一个较为重要因素。喉声门型癌声门下受侵患者,声门下受侵范围未超过声带游离缘下1.0cm,如无其它禁忌证,应行喉部分切除术;声门下受侵范围超过声带游离缘下1.0cm,应考虑行喉全切除术。淋巴结转移是影响声门下受侵喉声门型癌的重要因素,随着声门下受侵范围的增大,淋巴结转移率也随之增高。     

Paediatric subglottic stenosis

Most reports on paediatric subglottic stenosis have arisen from tertiary referral centres. At the Sheffield Children's Hospital, referrals come from the surrounding region such that almost all paediatric airway problems from this area are seen. This allows an opportunity to look at the overall picture of this condition. A retrospective study was performed to identify all children with subglottic stenosis requiring a tracheostomy since 1979 and to examine the management and eventual outcome in relation to the severity of their stenosis. Forty-two children were identified. There have been four mortalities, two of which have been tube related. Twenty-two laryngotracheoplasty procedures have been performed in 17 patients. Successful decannulation has been achieved in 82%. In the majority of children with more minor stenoses conservative management has lead to successful decannulation. However, with increasingly severe stenosis the necessity of undergoing a laryngotracheoplasty procedure to provide an adequate airway becomes more likely.     

Idiopathic subglottic stenosis revisited

Idiopathic subglottic stenosis (ISS) is a rare inflammatory process of unknown cause, usually limited to the subglottic region and the first 2 tracheal rings. We performed a retrospective analysis of our experience with a series of patients with this condition. The study involved retrospective review of the records of patients with ISS. A series of criteria that included patient clinical history, laboratory tests, flexible nasolaryngoscopic examination, and biopsies were used to establish a diagnosis. Symptoms, treatment, and outcome were examined. A total of 16 patients were identified; 14 were female (87.5%), and 2 were male. The mean follow-up time was 75.5 months. Fourteen patients required surgical treatment for respiratory compromise. Nine of these cases have been controlled effectively with endoscopic laser techniques. Endoscopic management failed in 5 patients, and 2 patients underwent laryngotracheal resection and reconstruction. Mitomycin-C was used in 6 patients as an adjuvant to endoscopic laser surgery. Patients in whom endoscopic treatment failed were noted to have thicker (>1 cm) and more complex stenoses. The diagnosis of ISS is a diagnosis of exclusion. A complete workup of the patient must be performed to rule out other causes of stenosis. Endoscopic laser surgery is a valid initial approach for thinner, noncomplicated lesions. Patients with thicker, complex lesions in whom endoscopic treatment fails are best managed with laryngotracheal resection and reconstruction. However, adjuvant use of mitomycin-C may prove beneficial in the treatment of these patients. Estrogen may play a role in the pathogenesis of ISS by altering the wound healing response.     

Management of subglottic stenosis

Evaluation and management of pediatric subglottic stenosis is complex and technically challenging. Laryngotracheal reconstruction has become the standard of care for symptomatic subglottic stenosis in children. Careful preoperative planning, meticulous surgery, and dedicated postoperative care are essential for a successful outcome. Early recognition and management of intraoperative and postoperative complications minimize their impact.     

Iatrogenic tracheal stenosis following endotracheal intubation: a study of 20 clinical cases

The authors report a case review series of 20 patients with tracheal stenosis after prolonged oral or nasotracheal intubation who underwent surgical treatment between 1995 and 1999. Seventeen were male (85%) and three (15%) were female. The age varied between 9 and 68 years (32.8 +/- 14.9 years). The stenotic area of the airway was limited to the trachea, and its length varied between 2 and 5 cm (3.3 +/- 1.2 cm.). All patients were treated surgically with an external approach for reconstruction after stenosis ablation. Follow up was at three and six months after surgery there were: 16 cases with (80%) good results, two (10%) with satisfactory results and two unsatisfactory (10%). We found a statistically significant correlation (Spearman correlation) of 5% level between the period of tracheal intubation and patient's age (R = 0.478, p = 0.033).     

Histopathology of congenital subglottic stenosis

A precise delineation of each laryngeal abnormality is critical to planning rational therapy. Since congenital cricoid cartilage anomalies are easily overlooked, a systematic approach to their identification is as important as a clear concept of their classification. The purpose of this communication is to present the pathologic findings and classification of congenital cricoid cartilage deformities and to summarize updated information derived by the whole organ macrosection technique. The classification of congenital subglottic stenosis is based on study of the English-language literature and the collection in the Laryngeal Development Laboratory at The Children's Memorial Hospital in Chicago. Twenty-nine specimens with congenital cricoid abnormalities have been identified. Fourteen have an elliptical cricoid cartilage; 12, a laryngeal cleft; 5, a flattened shape: 1, a large anterior lamina; and 3, generalized thickening. Some specimens have more than 1 anomaly. Eight cases of fragmented or distorted cricoid cartilages are thought to be acquired lesions. An anterior submucous cricoid cleft has been identified and is presented for the first time.     

Acquired subglottic stenosis in children

Subglottic stenosis is a disorder characterized by narrowing of the airway below the glottis or apposing edges of the true vocal cords. In a broad definition, the term may be used to describe airway compromise in the regions of the larynx or the trachea or both. In children, the stenosis is usually due to scar formation secondary to prolonged airway intubation, rather than to external trauma. The location and extent of the stenosis are highly variable; consequently, corrective measures need to be selected to suit the individual problem. In the present series of children, conservative treatment was adequate for lesser degrees of stenosis; those with more severe scarring required external laryngeal surgery. The preoperative evaluation and treatment plans are reviewed.     

Management of neonatal subglottic stenosis

When considering management of subglottic stenosis, all conservative efforts to establish a satisfactory airway must be considered prior to surgical reconstruction. However, the approach which allows for the earliest possible decannulation is the one which is sought because of high morbidity and mortality of tracheostomy in the pediatric population.     

Histopathology of congenital subglottic stenosis

Three patients with congenital subglottic stenosis are presented and whole organ serial-section studies of their larynges are discussed. A superiorly displaced first tracheal ring is observed to form a cartilaginous subglottic stenosis in one. This “trapped first ring” is demonstrated in horizontal, sagittal and coronal planes. Subglottic stenosis is a clinical diagnosis which describes multifarious histopathological forms of narrowing within the subglottic larynx.     

Acoustical effects of endotracheal intubation

Certain acoustical consequences of endotracheal intubation were examined in 13 male cardiovascular-surgery patients. Each subject recorded three tokens of a sustained vowel 1 day before intubation, 1 day after, upon discharge, and during a follow-up visit. Eight acoustical measures were obtained from the audio-recorded vowels: (a) mean fundamental frequency (Fo), (b) Fo standard deviation, (c) Fo perturbation quotient, (d) mean sound pressure level (SPL), (e) SPL standard deviation, (f) SPL perturbation quotient, (g) spectral flatness of the residue signal, and (h) coefficient of excess. Mean Fo, Fo standard deviation, mean SPL, SPL standard deviation, and coefficient of excess did not differ significantly across recording sessions, although certain predictable trends were apparent. Fo perturbation quotient, SPL perturbation quotient, and spectral flatness of the residue signal varied significantly across sessions, implying that these acoustical measures may be useful in the identification and monitoring of even minor intubation-related laryngeal trauma.