Congenital Tracheal Stenosis

Composite Biosynthetic Graft for Repair of Long-Segment Tracheal Stenosis: A Pilot In Vivo and In Vitro Feasibility Study

Pediatric patients who undergo surgery for long-segment congenital tracheal stenosis (LSCTS) have suboptimal outcomes and postsurgical complications. To address this, we propose a biosynthetic graft comprising (1) a porcine small intestinal submucosa extracellular matrix (SIS-ECM) patch for tracheal repair, and (2) a resorbable polymeric exostent for biomechanical support. The SIS-ECM patch was evaluated in vivo in an ovine trachea model over an 8 month period. Concurrently, the biosynthetic graft was evaluated in a benchtop lamb trachea model for biomechanical stability. In vivo results show that SIS-ECM performs better than bovine pericardium (control) by preventing granulation tissue/restenosis, restoring tracheal architecture, blood vessels, matrix components, pseudostratified columnar and stratified epithelium, ciliary structures, mucin production, and goblet cells. In vitro tests show that the biosynthetic graft can provide the desired axial and flexural stability, and biomechanical function approaching that of native trachea. These results encourage future studies to evaluate safety and efficacy, including biomechanics and collapse risk, biodegradation, and in vivo response enabling a stable long-term tracheal repair option for pediatric patients with LSCTS and other tracheal defects.

Three-dimensional reconstruction of trachea using computed tomography imaging as therapy for tracheal stenosis in infants

BACKGROUND AND OBJECTIVE

In this study, we aim to develop a system that uses computed tomography (CT) imaging for three-dimensional (3D) reconstruction of the trachea as therapy for tracheal stenosis in infants, and further calculate the cross-sectional area and volume, assisting doctors in clinical diagnosis.

METHODS

We first used image processing, calculating the cross-sectional area and volume. We used the improved median filter for image processing and designed the system for capturing the cross-sectional area of endotracheal tube. We then established 3D reconstruction images with isosurface extraction technology and calculated the cross-sectional area and volume. Medical indicator data analysis was performed.

RESULTS

The median filter developed in this study performed better in filtering speckle noise compared to traditional filtering methods. Furthermore, the median filter can keep fine texture feature, so that the subsequent contour selection and 3D reconstructed volume are more accurate. We also proposed new medical grading indexes according to tracheal obstruction volume ratio to assist doctors with the diagnosis and provide recommendations on treatment. Seventeen samples were examined in this study. Four sections of each sample are reviewed. Sixty-eight sections were used for validation, and the overall accuracy is very reliable.

CONCLUSIONS

Using image processing we obtained tracheal CT images before 3D reconstruction and calculated the cross-sectional area and volume of the trachea. New medical indicators are proposed according to the location and severity of stenosis to assist doctors with diagnosis.

Emergency management for congenital tracheal stenosis with endoluminal stenting in pediatric intensive care units

OBJECTIVE

The objective of this study was to share our experience in the management of congenital tracheal stenosis (CTS) using self-expanding intraluminal stents in infants.

METHODS

From January 2010 to August 2012, 31 infants with CTS treated using stents by bronchoscope in pediatric intensive care units (PICUs) were recruited for this study.

RESULTS

Among the 31 patients, 17 were male and 14 were female with their ages ranging from 55 days to 22 months. CTS was associated with congenital heart disease (CHD) in 22 patients. There were no immediate stent-related airway complications. A significant and immediate improvement of respiratory obstruction following stent placement in all 31 patients led to successful weaning from the breathing machine and extubation. Granulation tissue formation as a complication was observed in three (9.7%) patients, but all were successfully managed using cryotherapy. During follow up (up to 24 months), stents in 29 infants remained functional. In seven cases, stents were retrieved under bronchoscope (the same day to 10 months), and three cases required stent replacement (each of the three cases had the stent replaced three times). Nine infants died after stenting due to other causes and two infants abandoned treatment.

CONCLUSION

Airway stenting may provide an important therapeutic option in infants with CTS.

Cav3.2 T-type calcium channel is required for the NFAT-dependent Sox9 expression in tracheal cartilage

Intracellular Ca(2+) transient is crucial in initiating the differentiation of mesenchymal cells into chondrocytes, but whether voltage-gated Ca(2+) channels are involved remains uncertain. Here, we show that the T-type voltage-gated Ca(2+) channel Cav3.2 is essential for tracheal chondrogenesis. Mice lacking this channel (Cav3.2(-/-)) show congenital tracheal stenosis because of incomplete formation of cartilaginous tracheal support. Conversely, Cav3.2 overexpression in ATDC5 cells enhances chondrogenesis, which could be blunted by both blocking T-type Ca(2+) channels and inhibiting calcineurin and suggests that Cav3.2 is responsible for Ca(2+) influx during chondrogenesis. Finally, the expression of sex determination region of Y chromosome (SRY)-related high-mobility group-Box gene 9 (Sox9), one of the earliest markers of committed chondrogenic cells, is reduced in Cav3.2(-/-) tracheas. Mechanistically, Ca(2+) influx via Cav3.2 activates the calcineurin/nuclear factor of the activated T-cell (NFAT) signaling pathway, and a previously unidentified NFAT binding site is identified within the mouse Sox9 promoter using a luciferase reporter assay and gel shift and ChIP studies. Our findings define a previously unidentified mechanism that Ca(2+) influx via the Cav3.2 T-type Ca(2+) channel regulates Sox9 expression through the calcineurin/NFAT signaling pathway during tracheal chondrogenesis.

Successful diagnosis and treatment of congenital tracheal web using a fiberoptic bronchoscope

Congenital tracheal web is a very rare abnormality that often manifests as wheezing, dyspnea, and respiratory failure. Misdiagnosis is common. Here we describe the case of a 47-day-old female infant who presented after severe, extended coughing. The diagnosis of congenital tracheal web was made following coronal computer tomography (CT) reconstruction and bronchoscopy. The bronchoscope was used to facilitate tracheal expansion. This is the youngest case reported to date to highlight the diagnosis and treatment of a 47 days infant with congenital tracheal web. An infant with tracheal web, a very rare congenital anomaly can be clearly diagnosed by coronal CT reconstruction combined with bronchoscopy. If diagnosed early, the bronchoscope may be used to facilitate tracheal expansion.