Autoimmune hypothesis of acquired subglottic stenosis in premature infants

Non-oral manifestations in adults with a clinical and molecularly confirmed diagnosis of periodontal Ehlers-Danlos syndrome

Introduction: Periodontal Ehlers-Danlos Syndrome (pEDS) is a rare autosomal dominant type of EDS characterised by severe early-onset periodontitis, lack of attached gingiva, pretibial plaques, joint hypermobility and skin hyperextensibility as per the 2017 International EDS Classification. In 2016, deleterious pathogenic heterozygous variants were identified in C1R and C1S, which encode components of the complement system. Materials and Methods: Individuals with a clinical suspicion of pEDS were clinically and molecularly assessed through the National EDS Service in London and Sheffield and in genetic services in Austria, Sweden and Australia. Transmission electron microscopy and fibroblast studies were performed in a small subset of patients. Results: A total of 21 adults from 12 families were clinically and molecularly diagnosed with pEDS, with C1R variants in all families. The age at molecular diagnosis ranged from 21-73 years (mean 45 years), male: female ratio 5:16. Features of easy bruising (90%), pretibial plaques (81%), skin fragility (71%), joint hypermobility (24%) and vocal changes (38%) were identified as well as leukodystrophy in 89% of those imaged. Discussion: This cohort highlights the clinical features of pEDS in adults and contributes several important additional clinical features as well as novel deleterious variants to current knowledge. Hypothetical pathogenic mechanisms which may help to progress understanding and management of pEDS are also discussed.

Obstructive inflammatory tracheal pseudomembrane

Pathologies acquired after the establishment of an artificial airway include stenosis, granulomas and the formation of pseudomembranes, to name a few. The most common form of presentation in adults is circumferential stenosis, which often requires therapeutic endoscopic measures to achieve resolution. This Case Report describes the case of an obstructive inflammatory tracheal pseudomembrane in the shape of a tracheal septum secondary to repeated intubations that was resolved with conservative treatment. The clinical presentation of this entity generally includes the appearance of respiratory infection and/or atelectasis after the withdrawal of the orotracheal tube as a consequence of the accumulation of secretions between the tracheal wall and the pseudomembrane. Inflammatory pseudomembranes can resolve spontaneously with the help of glucocorticoids, although on occasion they require an invasive endotracheal procedure depending on the evolution.

Acquired paediatric subglottic cysts: a series from Manchester

Subglottic cysts (SGC) have long been regarded as a rare cause of airway obstruction but through increased awareness an increase in the number of cases of SGC has been reported.

OBJECTIVE

This paper describes the pathogenesis and management of SGC.

DESIGN

Retrospective case series. Ethical approval not sought.

SETTING

Royal Manchester Children's Hospital.

PATIENTS

Two hundred and six new referrals for direct laryngotracheobronchoscopy (DLTB) were identified from records between September 2003 and September 2005.

MAIN OUTCOMES MEASURED

Age at birth, sex, length of intubation, presenting symptoms, age at presentation, DLTB findings, interventional procedures, and follow-up DLTBs.

RESULTS

Fourteen out of 206 (6.8%) infants were diagnosed as with subglottic cysts. This represented the fourth most common cause of upper airway pathology. Thirteen out of 14 (93%) infants were preterm (26.8 weeks S.D. 25.3-28.3 weeks). All infants had been intubated ranging from 1 to 180 days (median 42 days). The onset of symptoms ranged from 1 to 13 months (median 4.25 months). Initially, 8/14 (57.2%) infants had SGC cysts marsupialised with microforceps. A further six cysts (50%) were decapped between 2 and 4 months and one between 6 and 12 months.

CONCLUSION

The number of cases of SGC has been increasing over the last three decades and represents the fourth most common causes of airway obstruction in our series. There is a delay in onset of symptoms and high rate of recurrence in the first 4 months. It is therefore prudent to reschedule further endoscopic evaluation between 2 and 4 months and after 6 months should the clinical need arise.

Neonatal subglottic stenosis--incidence and trends

OBJECTIVE/HYPOTHESIS

Neonatal subglottic stenosis is a known entity arising from endotracheal tube intubation. In the 1970s and 1980s, estimates of the incidence of subglottic stenosis were in the range of 0.9% to 8.3% of intubated neonates. Because of improved techniques of handling neonates who require ventilatory support, we thought the actual incidence of neonatal subglottic stenosis in the late 1990s was much lower.

STUDY DESIGN

We retrospectively reviewed all neonatal intensive-care unit (NICU) admissions from 1997 at our institution, which serves as a level 3 NICU. We also performed a MEDLINE search of the reported incidence of neonatal subglottic stenosis between 1960 and 1999.

METHODS

Analysis was performed to identify all children who developed subglottic stenosis at our institution. Data were also collected and analyzed with regard to average gestational age, average birth weight, average duration of intubation, and the number of children requiring tracheostomy. The reports identified in the literature were reviewed as to the incidence of subglottic stenosis.

RESULTS

A total of 544 neonates were admitted to the unit. Of these, 281 were intubated for an average of 11 days. No patients developed subglottic stenosis. Three patients required tracheostomies for other reasons. All studies published after 1983 reported an incidence of neonatal subglottic stenosis as less than 4.0%, and all studies published after 1990 reported an incidence of neonatal subglottic stenosis as less than 0.63%.

CONCLUSIONS

Although our report applies to only a single institution in a single year, after reviewing the literature we think a downward trend exists in the incidence of neonatal subglottic stenosis in the late 1990s. The current incidence of neonatal subglottic stenosis is likely between 0.0% and 2.0%.

Changing trends in neonatal subglottic stenosis

OBJECTIVES

To determine whether there are any changes in the incidence and management of neonatal subglottic stenosis (SGS).

METHODS

A retrospective chart review of 416 infants who were admitted to the neonatal intensive care unit of the Children's National Medical Center between July 1, 1995, and June 30, 1996, was carried out. The incidence of airway obstruction requiring anterior cricoid split or placement of tracheotomy tube was determined and compared with the incidence studied 10 years ago at the same institution.

RESULTS

One of 416 neonates required surgical intervention for airway obstruction caused by SGS, for an overall neonatal SGS incidence of 0.24%. When only the neonates who were intubated for 48 hours or longer were considered, the incidence of SGS was 0.49% (1/204). In neonates who were intubated for 48 hours or longer and survived, the incidence of SGS was 0.63% (1/160). This is in comparison with the incidences of 0.65% (3/462), 1.5% (3/195), and 1.9% (3/159), respectively, seen in a study done at the Children's National Medical Center 10 years ago. Five infants in this current study required placement of a tracheotomy tube for reasons other than SGS. Two infants needed tracheotomy tube placement for micrognathia, and 3 others for central hypotonia, an omphalocele that required multiple surgical procedures, and choanal atresia with a serious heart anomaly, which was a manifestation of CHARGE association. None of these 5 infants had evidence of SGS at rigid endoscopy preceding the tracheotomy tube placement.

CONCLUSION

The incidence and management of neonatal SGS remain unchanged during this study period when compared with those of 10 years ago.

A role for genetic predisposition in subglottic stenosis

We present the development of ASGS in two of three premature male triplets; the affected infants were monozygotic, while the unaffected triplet was dizygotic. All three shared remarkably similar risk factor profiles. There is suggested the existence of a genetic factor or factors which may predispose certain infants to the development of ASGS. The expression of such genetic influence may be expressed through the a priori presence of CSGS or other genetically based mechanisms including abnormal cartilage growth or development, specific patterns of chondral or mucosal injury, the action of specific growth factors, or the effects of autoimmune or inflammatory mediators. We propose that genetic predisposition be considered a possible risk factor in the development of subglottic stenosis.

Autoimmune hypothesis of acquired subglottic stenosis: lack of support at time of surgical repair in children

Numerous mechanisms have been suggested for the development of subglottic stenosis. This study sought serum antibody and cricoid cartilage immunohistologic evidence of an autoimmune process. The autoimmune hypothesis is that subglottic inflammation may extend into the cricoid cartilage, degrade the extracellular matrix and expose normally-sequestered type II collagen to the afferent arm of the immune system. The resultant anti-collagen antibodies are hypothesized to contribute to further injury and scarring. Specimens were obtained from 10 patients. Immunofluorescent stains for antibodies in histologic specimens, and serum antibodies to type II and type IX collagen were sought. No evidence for an autoimmune process was found in these specimens with the techniques used. The negative findings may be attributable to the autoimmune process being inactive at the mature stage of the disease in the patients studied.

Subglottic ulceration and healing following endotracheal intubation in the neonate: a morphometric study

In neonates, acquired subglottic stenosis is the most serious long-term complication of endotracheal intubation and is due primarily to posttraumatic fibrosis of the infant larynx. We have examined 78 larynges, 75 of which were intubated, from infants ranging in gestation from 22 to 40 weeks, and who survived from a few hours to up to 300 days. Each larynx was morphometrically assessed for the extent of acute injury, indicated by the percentage of epithelial loss, and healing, indicated by the percentage of a subglottic ulcer covered by metaplastic squamous epithelium. Results show that acute injury is almost invariable, and up to 100% of the subglottic epithelium may be lost within a few hours of intubation, but that progression of injury is relatively short-lived. Ulcer healing starts after a few days, rapidly progresses from day 10, and in the majority of cases is complete after 30 days. This study suggests that long-standing acute injury in the subglottis is the exception rather than the rule, even with the endotracheal tube remaining in place.