Slide tracheoplasty

Surgical management of long-segment congenital tracheal stenosis with tracheobronchial malacia

OBJECTIVES

Slide tracheoplasty has become the mainstream treatment for long-segment congenital tracheal stenosis (LSCTS). However, technical improvements are still needed to improve the clinical outcomes of patients exhibiting LSCTS with tracheobronchial malacia.

METHODS

LSCTS patients who underwent tracheoplasty from January 2010 to December 2020 were reviewed. According to the time of surgical technique modifications for reconstructing a supportive carina, the patients were divided into 2 groups: group A (2010-2018) and group B (2019-2020). We identified a well-balanced cohort matched by propensity score to evaluate the differences in surgical outcomes between the 2 groups.

RESULTS

There were no significant differences between group A and group B in any of the 8 characteristics before and after propensity score matching. In the propensity score-matched cohort, the number of patients who accepted anterior carina tracheopexy (75/77 vs 4/77, P < 0.001) and in situ pericardium insertion (75/77 vs 14/77, P < 0.001) in group B was significantly greater than that in group A. The mechanical ventilation time [48.3 (interquartile range: 29.6, 116.3) h vs 73.3 (interquartile range: 47.9, 111.6) h, P = 0.009] and cumulative mortality (P = 0.023) were significantly lower in Group B than Group A.

CONCLUSIONS

Reconstructing a supportive, stable carina of the neotrachea and tracheobronchopexy are helpful to improve the outcomes of slide tracheoplasty.

Surgical Treatment of Patients with Full Tracheal Rings: Our Experience

Introduction: Complete tracheal rings are a rare pathology occurring in 1 out of 100,000 live births. It is rare isolated tracheal or tracheobronchial anomaly resulting from abnormal cartilage growth, forming a complete ring, and leading to airway stenosis. A sliding tracheoplasty, primarily described by Tsang et al. and later widely presented by Grillo et al., overlaps the tracheal stenosing segments and shortens the trachea itself, and thus increases the diameter and circumference of the stenosing area double up. Materials and Methods: We have performed four slide tracheoplasties in the period between February 2019 and December 2020 in children who underwent medical treatment in the department of thoracic surgery in our center. Median age was 10 ± 5.5 months (2 months-1 year 6 months). Median weight was 6.9 ± 1.9 kg (4.5-9 kg). Slide tracheoplasty was performed using central venoarterial extracorporeal membrane oxygenation in 3 cases and using cardiopulmonary bypass in 1 case. Results: Patients were on artificial lung ventilation for 2-6 days in the postoperative period. Patients were discharged 14-18 days after the surgery. There were no lethal outcomes in our study. Discussion: Long segment congenital tracheal stenosis is an often and serious life-threatening anatomical malformation that bounded the length of trachea >50%. There is no unique treatment strategy for patients with such pathology. Sliding tracheoplasty can be recommended for all, but not for the shortest segments of stenosis, as it creates permissible voltage fluctuations during tracheal anastomosis. Excellent results in management of such severe patients can be achieved only through the collaboration of multidisciplinary team of specialists sharing organized and consistent patient-oriented approach.

Infectious complications after tracheoplasty for congenital tracheal stenosis: a retrospective comparative study

PURPOSE

The factors related to infectious complications after tracheoplasty for congenital tracheal stenosis (CTS) remain unclear; we, therefore, assessed these factors in this study.

METHODS

We divided 47 patients who underwent slide tracheostomy and tracheal resection for CTS between May 2016 and December 2020 into an infected group and a non-infected group. Their characteristics were compared between groups. Results are presented as the median (range) or incidence.

RESULTS

Infectious complications were observed in 12 patients (25.5%). Empyema and mediastinitis were seen in 5 cases (10.6%). There was a significant difference in the following factors in the infected and non-infected groups, respectively: weight, 5457 (2868-20,750) g and 6554 (2275-20,800) g (p = 0.025); surgical time, 575.5 (313-646) min and 349 (270-651) min (p < 0.001); extracorporeal circulation time, 303.5 (186-610) min and 216 (117-478) min (p = 0.001); and postoperative intubation time, 13 (7-28) days, and 6 (5-22) days (p < 0.001). Age, malnutrition, cardiovascular comorbidities, and preoperative methicillin-resistant Staphylococcus aureus detection were not significantly different between the two groups.

CONCLUSION

There were a few serious infectious complications and no perioperative deaths. Attention should be paid to low body weight, long surgical and extracorporeal circulation time, and intubation time in relation to infectious complications.

Risk of Pediatric Cardiac Surgery Increased in Patients Undergoing Tracheal Surgery During the Same Hospitalization

BACKGROUND

The impact of complex tracheal surgery (TS) on outcomes of children undergoing cardiac surgery has rarely been investigated in large national databases and could impact anticipated outcomes in those patients.

METHODS

The Pediatric Health Information System database was reviewed from January 1, 2005 to December 31, 2014, for pediatric (<18 years) patients undergoing select cardiac surgical procedures using International Classification of Disease-9 procedural coding. Patients were divided based upon having TS (excluding tracheostomy) during the same hospitalization. Patients with tracheal and cardiac surgeries (CHS + TS) were propensity matched in a 1 : 2 fashion to patients undergoing isolated cardiac surgeries without TS (CHS) based upon cardiac procedure(s), age at surgery, gender, and discharge year. Hospital mortality and other outcomes were compared between the 2 matched groups.

RESULTS

The 283 CHS + TS patients were similar to the 566 CHS patients in gender, race, age, cardiac procedures, and presence of chromosomal abnormalities, all P > .05. Hospital mortality was 13.8% (n = 39) for CHS + TS and 5.8% (n = 33) for CHS patients with an unadjusted 2.58 hazard ratio of death (95% confidence interval: 1.59-4.20; P < .001). CHS + TS was also associated with a greater length of stay (63 days vs 12 days), a higher cost per hospitalization ($322 402 vs $80 273), and more readmissions (64.3% [n = 182] vs 41.8% [n = 243]), all P < .001.

CONCLUSIONS

Patients undergoing cardiac and TS in the same hospitalization are at greater risk of in-hospital mortality than patients undergoing similar cardiac surgeries alone and incur higher resource utilization thereafter. The increased risk of mortality is currently underappreciated, but it is important to recognize when discussing expectations with families and providers.

Standardization of Microcomputed Tomography for Tracheal Tissue Engineering Analysis

Tracheal tissue engineering has become an active area of interest among clinical and scientific communities; however, methods to evaluate success of in vivo tissue-engineered solutions remain primarily qualitative. These evaluation methods have generally relied on the use of photographs to qualitatively demonstrate tracheal patency, endoscopy to image healing over time, and histology to determine the quality of the regenerated extracellular matrix. Although those generally qualitative methods are valuable, they alone may be insufficient. Therefore, to quantitatively assess tracheal regeneration, we recommend the inclusion of microcomputed tomography (μCT) to quantify tracheal patency as a standard outcome analysis. To establish a standard of practice for quantitative μCT assessment for tracheal tissue engineering, we recommend selecting a constant length to quantify airway volume. Dividing airway volumes by a constant length provides an average cross-sectional area for comparing groups. We caution against selecting a length that is unjustifiably large, which may result in artificially inflating the average cross-sectional area and thereby diminishing the ability to detect actual differences between a test group and a healthy control. Therefore, we recommend selecting a length for μCT assessment that corresponds to the length of the defect region. We further recommend quantifying the minimum cross-sectional area, which does not depend on the length, but has functional implications for breathing. We present empirical data to elucidate the rationale for these recommendations. These empirical data may at first glance appear as expected and unsurprising. However, these standard methods for performing μCT and presentation of results do not yet exist in the literature, and are necessary to improve reporting within the field. Quantitative analyses will better enable comparisons between future publications within the tracheal tissue engineering community and empower a more rigorous assessment of results. Impact statement The current study argues for the standardization of microcomputed tomography (μCT) as a quantitative method for evaluating tracheal tissue-engineered solutions in vivo or ex vivo. The field of tracheal tissue engineering has generally relied on the use of qualitative methods for determining tracheal patency. A standardized quantitative evaluation method currently does not exist. The standardization of μCT for evaluation of in vivo studies would enable a more robust characterization and allow comparisons between groups within the field. The impact of standardized methods within the tracheal tissue engineering field as presented in the current study would greatly improve the quality of published work.

Repair of pulmonary artery sling with tracheal and intracardiac defects

BACKGROUND

Pulmonary artery sling is commonly associated with tracheal stenosis and intracardiac anomalies. While surgical repair is standardized, coexistent anomalies often determine outcomes. With the paucity of risk stratification, this study aimed to review our experience and stratify risk factors for the surgical outcome of complex pulmonary artery sling repair in the presence of airway or intracardiac lesions.

METHODS

Seventy-nine consecutive children with pulmonary artery sling were evaluated retrospectively following surgical repair. Median age at surgery was 5 months (interquartile range 3-9). Surgical approaches included pulmonary artery sling alone (n = 10), pulmonary artery sling with tracheoplasty (n = 41), and pulmonary artery sling with both intracardiac and tracheal surgery (n = 28).

RESULTS

There were 7 early (8.8%) deaths. Two patients after left pulmonary artery reimplantation needed revision of the anastomosis. The median intensive care and hospital stay were 11 (interquartile range 9.2-24.8) and 17.9 (interquartile range 4.3-19.8) days, and considerably longer when associated tracheal surgery (p = 0.002). Follow-up was complete in 66/69 and 3 (3.8%) children died late: 2.7, 10.2, and 17 months after surgery. Univariate analysis showed abnormal lung and coexisting structural heart disease as risk factors. Multivariate analysis revealed total cardiopulmonary bypass time as an independent predictor of overall mortality.

CONCLUSION

Complex pulmonary artery sling repair can be performed with a good surgical outcomes even when associated with airway malformations or structural heart diseases. Lung abnormality and longer cardiopulmonary bypass time as a surrogate marker of complex surgery, are possible risk factors.

Quality of life can be good after slide tracheoplasty for long-segment tracheal stenosis

OBJECTIVES

The objectives of this study were to measure 'health-related quality of life' (HRQoL) in children following slide tracheoplasty for long-segment tracheal stenosis (LSTS) and to explore the relationship of comorbidities and parental mental health with HRQoL outcomes.

METHODS

A cross-sectional study was undertaken with children who had undergone slide tracheoplasty. Participants included parents and children (age 5-15 years) recruited over a 13-month period, who were asked to complete validated measures of HRQoL, development and behaviour. Scores were compared to published norms.

RESULTS

Forty-two children (male 69%; n = 29) were included; mean age was 5.3 (standard deviation 3.5) years and mean follow-up was 45 (range 4-179) months. Mean total HRQoL scores for children with repaired LSTS did not differ from those of healthy norms other than for children aged 13-23 months, but 10 children (24%) had scores >2 SD below the mean for healthy children. HRQoL was poorer in children with non-cardiac congenital comorbidities than in those with isolated LSTS (mean scores 60.34 ± 17.19 and 85.52 ± 12.19, respectively, P = 0.01). There was good agreement between children's and parents' scores, although children rated their HRQoL as better than their parents did. Anxious parents rated their children's HRQoL as significantly worse than non-anxious parents (P<0.001).

CONCLUSIONS

Older children with isolated LSTS can have excellent HRQoL after surgery. Younger children, at an earlier time point postoperatively, and those with non-cardiac congenital comorbidities have poorer HRQoL. Further longitudinal evaluation is required to identify psycho-social (including parental) predictors of outcome which may inform, or be amenable to, intervention.

Biomedical grafts for tracheal tissue repairing and regeneration "Tracheal tissue engineering: an overview"

Airway system is a vital part of the living being body. Trachea is the upper respiratory portion that connects nostril and lungs and has multiple functions such as breathing and entrapment of dust/pathogen particles. Tracheal reconstruction by artificial prosthesis, stents, and grafts are performed clinically for the repairing of damaged tissue. Although these (above-mentioned) methods repair the damaged parts, they have limited applicability like small area wounds and lack of functional tissue regeneration. Tissue engineering helps to overcome the above-mentioned problems by modifying the traditional used stents and grafts, not only repair but also regenerate the damaged area to functional tissue. Bioengineered tracheal replacements are biocompatible, nontoxic, porous, and having 3D biomimetic ultrastructure with good mechanical strength, which results in faster and better tissue regeneration. Till date, the bioengineered tracheal replacements studies have been going on preclinical and clinical levels. Besides that, still many researchers are working at advance level to make extracellular matrix-based acellular, 3D printed, cell-seeded grafts including living cells to overcome the demand of tissue or organ and making the ready to use tracheal reconstructs for clinical application. Thus, in this review, we summarized the tracheal tissue engineering aspects and their outcomes.

Biodegradable electrospun patch containing cell adhesion or antimicrobial compounds for trachea repair in vivo

Difficulty breathing due to tracheal stenosis (i.e. narrowed airway) diminishes the quality of life and can potentially be life-threatening. Tracheal stenosis can be caused by congenital anomalies, external trauma, infection, intubation-related injury, and tumors. Common treatment methods for tracheal stenosis requiring surgical intervention include end-to-end anastomosis, slide tracheoplasty and/or laryngotracheal reconstruction. Although the current methods have demonstrated promise for treatment of tracheal stenosis, a clear need exists for the development of new biomaterials that can hold the trachea open after the stenosed region has been surgically opened, and that can support healing without the need to harvest autologous tissue from the patient. The current study therefore evaluated the use of electrospun nanofiber scaffolds encapsulating 3D-printed PCL rings to patch induced defects in rabbit tracheas. The nanofibers were a blend of polycaprolactone (PCL) and polylactide-co-caprolactone (PLCL), and encapsulated either the cell adhesion peptide, RGD, or antimicrobial compound, ceragenin-131 (CSA). Blank PCL/PLCL and PCL were employed as control groups. Electrospun patches were evaluated in a rabbit tracheal defect model for 12 weeks, which demonstrated re-epithelialization of the luminal side of the defect. No significant difference in lumen volume was observed for the PCL/PLCL patches compared to the uninjured positive control. Only the RGD group did not lead to a significant decrease in the minimum cross-sectional area compared to the uninjured positive control. CSA reduced bacteria growth in vitro, but did not add clear value in vivo. Adequate tissue in-growth into the patches and minimal tissue overgrowth was observed inside the patch material. Areas of future investigation include tuning the material degradation time to balance cell adhesion and structural integrity.

Outcome of congenital tracheal stenosis in children over two decades in a national cardiothoracic surgical unit

OBJECTIVE

To assess the outcomes of congenital tracheal stenosis among children.

MATERIALS AND METHODS

A retrospective review of all children who underwent surgical repair of congenital tracheal stenosis reviewing charts, operative notes, echocardiograms, CT and MRI data from January 2002 to February 2019.

RESULTS

Twenty-six children underwent surgical treatment for tracheal stenosis. The median age was 3 months (range 0.3-35 months) and the median weight was 4.7 kg (range 2.5-13 kg) at the time of surgical intervention. Stridor was the most common presenting symptom in 17 patients (65% of patients). Twenty-one patients (81%) had concurrent cardiac anomalies, with pulmonary arterial sling being the most common, present in nine patients (34%). Extracorporeal life support was utilised in seven patients (27%) pre-operatively. Laryngeal release was required in 16 patients. In 7 patients an end-to-end anastomosis was performed, in 18 patients slide tracheoplasty, and 1 patient had a double slide tracheoplasty. The median cardiopulmonary bypass time was 106 minutes (range 25-255 minutes). The median cross-clamp time was 30 minutes (range 5-67 minutes). The median post-operative duration of ventilation was 5 days (range 0.5-16 days). The median ICU length of stay was 12.5 days (range 2-60 days). There were three hospital mortalities with 88% survival. One patient only required reintervention with balloon dilation. Twenty-two patients (85%) remained symptom-free on median follow-up at 7.6 years (range 0.2-17 years). Two patients since 2017 had 3D printed tracheas produced from CT imaging to assist surgical planning.

CONCLUSION

Congenital tracheal stenosis can be managed effectively with excellent outcomes and 3D printed models assist in planning the optimal surgical intervention.

Tracheal Replacement Therapy with a Stem Cell-Seeded Graft: Lessons from Compassionate Use Application of a GMP-Compliant Tissue-Engineered Medicine

Tracheal replacement for the treatment of end‐stage airway disease remains an elusive goal. The use of tissue‐engineered tracheae in compassionate use cases suggests that such an approach is a viable option. Here, a stem cell‐seeded, decellularized tissue‐engineered tracheal graft was used on a compassionate basis for a girl with critical tracheal stenosis after conventional reconstructive techniques failed. The graft represents the first cell‐seeded tracheal graft manufactured to full good manufacturing practice (GMP) standards. We report important preclinical and clinical data from the case, which ended in the death of the recipient. Early results were encouraging, but an acute event, hypothesized to be an intrathoracic bleed, caused sudden airway obstruction 3 weeks post‐transplantation, resulting in her death. We detail the clinical events and identify areas of priority to improve future grafts. In particular, we advocate the use of stents during the first few months post‐implantation. The negative outcome of this case highlights the inherent difficulties in clinical translation where preclinical in vivo models cannot replicate complex clinical scenarios that are encountered. The practical difficulties in delivering GMP grafts underscore the need to refine protocols for phase I clinical trials. Stem Cells Translational Medicine2017;6:1458–1464

A pilot study of a novel biodegradable magnesium alloy airway stent in a rabbit model

OBJECTIVE

To preliminarily investigate the feasibility of bioabsorption tracheal stenting for the therapeutic application of congenital tracheal stenosis (CTS).

STUDY DESIGN

Experimental research.

SETTING

Shanghai Children Medical Center, National Children's Medical Center.

SUBJECTS AND METHODS

Five kinds of magnesium alloys with different compositions were studied in this paper, a patented Mg-Nd-Zn-Zr alloy series namely JDBM (JiaoDa BioMg) and four Mg-Ca-Zn alloys. The cytotoxicity of alloys was evaluated by the MTS ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay in rabbit tracheal epithelial cells. Specific magnesium alloys had been immersed in the cell culture medium for 24 h. The tracheal stents that were made of magnesium alloy were implanted into the trachea of New Zealand rabbits and the ablation of the stent was monitored by fiber bronchoscopy. The routine blood examination was conducted prior to and following the stent placement. The rabbits were euthanized following 2-3 months of stenting. H&E staining of the main organs was conducted and the induction of apoptosis of the tracheal tissues was monitored.

RESULTS

The cytotoxicity of the JDBM magnesium alloy was mild and lower than the remaining 4 alloys. The stents were placed successfully in five animals. The tracheal stents were successfully placed and gradually biodegradated as monitored by fiber bronchoscopy; no significant systemic inflammatory response was noted. No significant differences in the liver and/or kidney function prior to and following stent placement were noted. H&E staining indicated the absence of pathological changes in the trachea, liver, heart and/or kidney tissues. The apoptotic assay indicated that the apoptosis ratio of the tracheal tissues was comparable between rabbits with and without tracheal stenting.

CONCLUSION

The results suggested the feasibility of bioabsorption stents made of biodegradable magnesium alloys using in patients with tracheal stenosis, especially in infants.

Pitfalls in the management of congenital tracheal stenosis: is conservative management feasible?

PURPOSE

Congenital tracheal stenosis (CTS) is rare and challenging. Complete tracheal rings cause a wide spectrum of airway-obstructing lesions and varying degrees of respiratory distress. Although surgical reconstruction is the primary option for symptomatic CTS, sometimes an appropriate management strategy may be difficult due to other anomalies. We aimed to identify pitfalls in the management of CTS.

METHODS

We retrospectively reviewed the records of patients with CTS during the last 10 years in our institution.

RESULTS

Sixteen pediatric patients were diagnosed with CTS. Of the 16 patients, 12 (75.0%) had cardiovascular anomalies including seven left pulmonary artery sling. Six patients with dyspnoea caused by CTS and three patients with difficult intubations due to CTS underwent tracheoplasty. Four patients underwent only cardiovascular surgery without tracheoplasty. Three asymptomatic patients were followed up without undergoing any surgical procedure. We repeatedly discussed management of four patients with especially complex pathophysiology at multidisciplinary meetings. Right ventricular outflow tract obstruction, tracheobronchial malacia, increased pulmonary blood flow, and pulmonary aspiration due to gastroesophageal reflux presumably accounted for their severe respiratory distress, and we forewent their tracheal reconstruction.

CONCLUSION

The management of CTS should be individualized, and conservative management is a feasible option in selected cases.

Reinforced Electrospun Polycaprolactone Nanofibers for Tracheal Repair in an In Vivo Ovine Model

Tracheal stenosis caused by congenital anomalies, tumors, trauma, or intubation-related damage can cause severe breathing issues, diminishing the quality of life, and potentially becoming fatal. Current treatment methods include laryngotracheal reconstruction or slide tracheoplasty. Laryngotracheal reconstruction utilizes rib cartilage harvested from the patient, requiring a second surgical site. Slide tracheoplasty involves a complex surgical procedure to splay open the trachea and reconnect both segments to widen the lumen. A clear need exists for new and innovative approaches that can be easily adopted by surgeons, and to avoid harvesting autologous tissue from the patient. This study evaluated the use of an electrospun patch, consisting of randomly layered polycaprolactone (PCL) nanofibers enveloping 3D-printed PCL rings, to create a mechanically robust, suturable, air-tight, and bioresorbable graft for the treatment of tracheal defects. The study design incorporated two distinct uses of PCL: electrospun fibers to promote tissue integration, while remaining air-tight when wet, and 3D-printed rings to hold the airway open and provide external support and protection during the healing process. Electrospun, reinforced tracheal patches were evaluated in an ovine model, in which all sheep survived for 10 weeks, although an overgrowth of fibrous tissue surrounding the patch was observed to significantly narrow the airway. Minimal tissue integration of the surrounding tissue and the electrospun fibers suggested the need for further improvement. Potential areas for further improvement include a faster degradation rate, agents to increase cellular adhesion, and/or an antibacterial coating to reduce the initial bacterial load.

Congenital tracheal malformations

Congenital malformations of the trachea include a variety of conditions that cause respiratory distress in neonates and infants. A number of anomalies are self-limiting while others are life-threatening and require immediate therapy. The prevalence of congenital airway malformations has been estimated to range between 0.2 and 1 in 10,000 live births. The most frequent congenital tracheal malformations are: tracheomalacia, congenital tracheal stenosis, laryngotracheal cleft and tracheal agenesis. The management of congenital tracheal malformations is complex and requires an individualized approach delivered by a multidiscipilinary team within centralized units with the necessary expertise.

Swallowing outcomes in children after slide tracheoplasty

INTRODUCTION

Slide tracheoplasty is now considered gold standard treatment for long segment congenital tracheal stenosis. Outcomes are typically focused upon airway patency. Dysphagia is often reported in children undergoing cardiothoracic surgery, but not specifically after slide tracheoplasty. This study was carried out to describe the nature and prevalence of dysphagia following slide tracheoplasty for long segment congenital tracheal stenosis.

METHODS

Retrospective case note review was conducted on a series of patients who underwent swallow evaluation following slide tracheoplasty between 2006 and 2014. A clinical swallow assessment was carried out by a Speech and Language Therapist with videofluoroscopic evaluation of swallowing where indicated. Logistic regression assessed the impact of gender, feeding history, weight, tracheal diameter, stenting and co-morbidities on the likelihood of having post-operative dysphagia.

RESULTS

43 out of 83 slide tracheoplasty patients underwent swallow evaluation. Dysphagia was identified in 30 (70%) of 43 patients. Videofluoroscopy was undertaken in 22 of these patients. All patients who had a videofluoroscopy presented with altered swallow physiology. Aspiration risk was confirmed in 15 patients with frank aspiration seen in 9. Pre-operative history of dysphagia was present in 9 patients. There were two cases of vocal fold palsy. The presence of a stent was the strongest predictor of post-operative dysphagia with an odds ratio of 10.6 (95% CI 1.2-92.8).

CONCLUSIONS

This study documents a high prevalence of post-operative dysphagia in a pediatric population following slide tracheoplasty. In most cases there was no history suggestive of dysphagia pre-operatively. Swallowing needs to be assessed after slide tracheoplasty and longitudinal studies are required.

Temporary tracheal stenting using endovascular prosthesis in the management of severe refractory stenosis following slide tracheoplasty

OBJECTIVES

To evaluate the role of endovascular stents in temporary tracheal stenting and endoscopic treatment strategy for patients with severe refractory tracheal stenosis following slide tracheoplasty.

METHODS

Two patients had severe tracheal stenosis after slide tracheoplasty for long segment congenital tracheal stenosis. Both these patients were managed endoscopically and an endovascular prosthesis was used to temporarily stent the trachea. Short and long term results were evaluated clinically and with repeated endoscopies.

RESULTS

The 2 patients had an excellent recovery immediately after the stent placement and continue to have an optimal, age-appropriate stable tracheal diameter after stent removal.

CONCLUSION

Endovascular stents can be temporarily used to stent the trachea in the endoscopic treatment strategy to correct refractory severe tracheal stenosis following slide tracheoplasty.

Slide tracheoplasty in 81 children: Improved outcomes with modified surgical technique and optimal surgical age

The aim of this study was to evaluate the surgical outcome of slide tracheoplasty.Eighty-one patients who underwent slide tracheoplasty were retrospectively reviewed. Before and after operation, all patients were examined by computed tomography (CT) and bronchoscopy regularly.There were 8 deaths and the mortality was 9.9%. They all died of respiratory failure associated with the formation of granulation tissue in the airway postoperatively. The mortality was 15.8% from 2009 to 2012 and decreased to 8.1% from 2013 to 2016. The mortality of patients aged 10 to 24 months was 5.7%, which was significantly lower than those younger than 10 months and those older than 24 months. After surgery, 11 patients had granulation tissue growing at anastomosis edges and 8 of them died eventually. Twenty patients had mucosa varus at the site of anastomosis which mainly happened in the early time. Between different time periods and different age groups, there was significant difference in the incidence of granulation tissue and mucosa varus (P < .01). Clinical symptoms of tracheal stenosis disappeared and the results of CT were satisfactory after operation.Slide tracheoplasty is an effective surgical method for congenital tracheal stenosis associated with congenital heart disease. With the continuous improvement of surgical technique, the mortality has been reduced and the incidence of granulation tissue and mucosa varus also has been reduced. The period of 10 to 24 months of age is the optimal cure time.

Tracheal Replacement Therapy with a Stem Cell-Seeded Graft: Lessons from Compassionate Use Application of a GMP-Compliant Tissue-Engineered Medicine

Tracheal replacement for the treatment of end-stage airway disease remains an elusive goal. The use of tissue-engineered tracheae in compassionate use cases suggests that such an approach is a viable option. Here, a stem cell-seeded, decellularized tissue-engineered tracheal graft was used on a compassionate basis for a girl with critical tracheal stenosis after conventional reconstructive techniques failed. The graft represents the first cell-seeded tracheal graft manufactured to full good manufacturing practice (GMP) standards. We report important preclinical and clinical data from the case, which ended in the death of the recipient. Early results were encouraging, but an acute event, hypothesized to be an intrathoracic bleed, caused sudden airway obstruction 3 weeks post-transplantation, resulting in her death. We detail the clinical events and identify areas of priority to improve future grafts. In particular, we advocate the use of stents during the first few months post-implantation. The negative outcome of this case highlights the inherent difficulties in clinical translation where preclinical in vivo models cannot replicate complex clinical scenarios that are encountered. The practical difficulties in delivering GMP grafts underscore the need to refine protocols for phase I clinical trials. Stem Cells Translational Medicine 2017;6:1458-1464.

Airway Problems in Neonates-A Review of the Current Investigation and Management Strategies

Airway problems in the neonatal population are often life threatening and raise challenging issues in diagnosis and management. The airway problems can result from congenital or acquired lesions and can be broadly classified into those causing obstruction or those due to an abnormal "communication" in the airway. Many different investigations are now available to identify the diagnosis and quantify the severity of the problem, and these tests can be simple or invasive. Bronchography and bronchoscopy are essential to determine the extent and severity of the airway problem and to plan treatment strategy. Further imaging techniques help to delineate other commonly associated abnormalities. Echocardiography is also important to confirm any associated cardiac abnormality. In this review, the merits and disadvantages of the various investigations now available to the clinician will be discussed. The current therapeutic strategies are discussed, and the review will focus on the most challenging conditions that cause the biggest management conundrums, specifically laryngotracheal cleft, congenital tracheal stenosis, and tracheobronchomalacia. Management of acquired stenosis secondary to airway injury from endotracheal intubation will also be discussed as this is a common problem. Slide tracheoplasty is the preferred surgical option for long-segment tracheal stenosis, and results have improved significantly. Stents are occasionally required for residual or recurrent stenosis following surgical repair. There is sufficient evidence that a multidisciplinary team approach for managing complex airway issues provides the best results for the patient. There is ongoing progress in the field with newer diagnostic tools as well as development of innovative management techniques, such as biodegradable stents and stem cell-based tracheal transplants, leading to a much better prognosis for these children in the future.

Three dimensional printing: A review on the utility within medicine and otolaryngology

Three dimensional (3D) printing is a novel technique that has evolved over the past 35 years and has the potential to revolutionize the field of medicine with its inherent advantages of customizability and the ability to create complex shapes with precision. It has been used extensively within the fields of orthopedics, dentistry, and craniofacial reconstruction with wide ranging utility including, medical modeling, surgical planning and the production of custom plates, screws and surgical guides. Furthermore, it has been used for similar means in the field of Otorhinolaryngology and also has potential to revolutionize the treatment of airway malacia. In fact, 3D printed external tracheal splints have already been studied in several pediatric patients with very promising results. The emerging field of 3D bioprinting, which integrates tissue engineering with 3D printing, may produce a paradigm shift with the potential introduction of customized functional biologic replacements.

Congenital tracheobronchial stenosis

Congenital tracheobronchial stenosis is a rare disease characterized by complete tracheal rings that can affect variable lengths of the tracheobronchial tree. It causes high levels of morbidity and mortality both due to the stenosis itself and to the high incidence of other associated congenital malformations. Successful management of this complex condition requires a highly individualized approach delivered by an experienced multidisciplinary team, which is best delivered within centralized units with the necessary diverse expertise. In such settings, surgical correction by slide tracheoplasty has become increasingly successful over the past 2 decades such that long-term survival now exceeds 88%, with normalization of quality of life scores for patients with non-syndrome-associated congenital tracheal stenosis. Careful assessment and planning of treatment strategies is of paramount importance for both successful management and the provision of patients and carers with accurate and realistic treatment counseling.

Airway tissue engineering for congenital laryngotracheal disease

Regenerative medicine offers hope of a sustainable solution for severe airway disease by the creation of functional, immunocompatible organ replacements. When considering fetuses and newborns, there is a specific spectrum of airway pathologies that could benefit from cell therapy and tissue engineering applications. While hypoplastic lungs associated with congenital diaphragmatic hernia (CDH) could benefit from cellular based treatments aimed at ameliorating lung function, patients with upper airway obstruction could take advantage from a de novo tissue engineering approach. Moreover, the international acceptance of the EXIT procedure as a means of securing the precarious neonatal airway, together with the advent of fetal surgery as a method of heading off postnatal co-morbidities, offers the revolutionary possibility of extending the clinical indication for tissue-engineered airway transplantation to infants affected by diverse severe congenital laryngotracheal malformations. This article outlines the necessary basic components for regenerative medicine solutions in this potential clinical niche.

[Sliding traсheal plasty in children under extracorporeal membrane oxygenation (first experience in Russia)]

AIM

To improve the results of surgical treatment of children with extended tracheal stenosis.

MATERIAL AND METHODS

Since 2013 slidingtraсheal plasty under extracorporeal membrane oxygenation was performed in 4 children aged 1 year 2 months - 4.5 years with extended tracheal stenosis in Children's City Clinical Hospital №13. Patients' weight was from 10,5 to 16 kg. Extended tracheal stenosis and complete cartilag inousrings were confirmed in all patients after peoperative survey. Indications for surgery were based on medical history data, the severity of respiratory failure and survey data. Sliding traсheal plasty by different approach esunder extracorporeal membrane oxygenation was applied in all patients.

RESULTS

There were no intraoperative complications. In the study group 1 patient died in remote postoperative period after discharge due to deterioration of his condition caused by upper respiratory tract infection and acute respiratory failure. In immediate postoperative period 1 patient had pronounced growth of granulation tissue in the area of anastomosis followed laser photocoagulation and prolonged intubation. The average ICU-stay was 24 days, the duration of mechanical ventilation - 11 days. Follow-up carefor patients was conducted on terms of 4-6 and 12 months after surgery. In 2 patients moderate complaints of recurrent bronchitis without signs of respiratory insufficiency during 6-8 months postoperatively were observed. In one child complaints were completely absent.

The influence of stents on microbial colonization of the airway in children after slide tracheoplasty: a 14-year single-center experience

OBJECTIVES

This study describes the microbial colonization profile of the airway in children after slide tracheoplasty (STP) with and without stents, and compares colonization to children undergoing cardiothoracic surgical procedures without airway related disease.

METHODS

A 14-year retrospective single case note review was performed on patients undergoing STP and stent insertion. Nose and throat (NT) and bronchoalveolar lavage (BAL) specimens were analyzed for microbial profile and expressed as cumulative mean microorganisms per patient (MMP).

RESULTS

Forty-three patients (median age ± SD 15.02 ± 31.76 months) underwent STP and 141 patients underwent cardiothoracic but no airway surgery (median age ± SD 31.7 ± 47.2 months). Sixteen patients required a stent after STP. One-hundred seventy-two positive microbial specimens were identified. The predominant 6 microorganisms were (1) Staphylococcus aureus; (2) Pseudomonas aeruginosa; (3) Haemophilus influenzae not type B; (4) Coliforms; (5) Streptococcus pneumoniae; and (6) Candida Albicans, and accounted for 128 (74%) of all positive specimens found. Children with stents had more MMP compared to children without stents after STP [4.06 ± 2.38 and 2.04 ± 2.24 MMP (P < 0.001), respectively]. Both groups of children after STP had more MMP compared to the control group (P < 0.001). Children with stents had more microbial colonization of their lower respiratory tract compared to their upper respiratory tract (3.36 ± 2.02 and 1.36 ± 0.93 MMP (P < 0.01) respectively). Staphylococcus aureus colonization of the lower respiratory tract was significantly higher in children with stents compared to children without stents after STP [0.5 and 0.15 MMP (P < 0.05) respectively].

CONCLUSIONS

This study indicates airway surgery and the subsequent use of stents to be a significant risk factor for microbial colonization of the airway in children. More specifically airway stents appear to increase colonization in the distal airway, which appears unrelated to that of the upper respiratory tract.

Treatment of postoperative tracheal granulation tissue with inhaled budesonide in congenital tracheal stenosis

PURPOSE

Tracheal obstruction by granulation tissue can compromise the postoperative course in congenital tracheal stenosis (CTS). Balloon dilatation and stenting may be required. Budesonide is a corticosteroid with topical anti-inflammatory effects. In 2008, we used inhaled budesonide for treatment of postoperative granulation tissue for the first time in CTS, resulting in significant improvement. The aim of this study was to evaluate the efficacy of inhaled budesonide for treatment of postoperative granulation tissue in CTS.

METHODS

Retrospective chart review was conducted. From 2004 through 2011, we performed 39 tracheoplasties. Forced stenting ± balloon dilatation (S/B) was required when airway obstruction with tissue granulation was life-threatening. We compared the requirement for S/B between the early group without budesonide (2004-Nov. 2008, Early) and the late group with budesonide (Dec. 2008-2011, Late). Statistical analysis was performed using Fisher's Exact test.

RESULTS

Eleven of 22 in Early and 8 of 17 in Late were successfully extubated, never having had life-threatening tissue granulation. The remaining patients in each group (11 in Early and 9 in Late) required tracheostomies due to postoperative complication. Ten in Early and 5 in Late with tracheostomies developed granulation tissue. Of these patients, the 10 in Early required S/B, while none of the 5 in Late required S/B (P=.0003). Bronchoscopy demonstrated significant regression of granulation tissue in all cases treated with inhaled budesonide.

CONCLUSION

Inhaled budesonide is effective for treatment of tracheal granulation tissue in patients with tracheostomies after repair of CTS.

Do tracheas grow after slide tracheoplasty?

BACKGROUND

Slide tracheoplasty has become the surgical technique of choice for repair of congenital tracheal stenosis. Despite the initial reluctance regarding the ability of this "reconstructed" trachea to grow, the reduced morbidity and mortality have allowed slide tracheoplasty to be widely adopted. The aim of this study was to evaluate tracheal growth after slide tracheoplasty.

METHODS

This was a retrospective study. In follow-up bronchography performed 1, 6, 12, 18, and 24 months after slide tracheoplasty, we measured the cross-sectional areas of the midtrachea and distal trachea at each investigation and correlated the measurements with the anthropomorphic factors (body weight, height, and body surface).

RESULTS

Fourteen patients were enrolled in this study. The midtracheal and distal tracheal cross-sectional areas significantly increased with time (p ≤ 0.0001). The average rates of midtracheal growth were 21.0 mm(2)year in the first 6 months and 8.0 mm(2)/year in the first 2 years, and the distal trachea grew 18.5 mm(2)/year and 8.4 mm(2)/year, respectively. Regression analysis showed that both the midtrachea and the distal trachea increase significantly with weight (r(2) = 0.257, p ≤ 0.0001), height (r(2) = 0.376, p ≤ 0.0001), and body surface area (r(2) = 0.315, p ≤ 0.0001). Balloon dilation did not significantly alter the tracheal growth in the first 2 years after slide tracheoplasty.

CONCLUSIONS

Slide tracheoplasty does not inhibit tracheal growth. The reconstructed trachea grows faster in the first 6 months and slows in the following 18 months. There is a positive correlation between tracheal cross-sectional area and weight, height, and body surface area.

Laser division of congenital complete tracheal rings

Congenital complete tracheal rings are a rare and life threatening problem in young children and they are often challenging to manage. Whilst historically associated with high mortality rates increasing experience with this tracheal pathology has led to much improved survival rates and slide tracheoplasty has become the treatment of choice. We present 3 cases in which an open procedure was not deemed possible and they underwent laser division (CO2, KTP) of their complete rings. Two patients subsequently required stent insertion. All patients are alive and well at a mean follow up of 3 years and 5 months. Whilst laser division of complete tracheal rings has only been described in a small number of cases it may provide an alternative approach in patients who are not able to undergo an open procedure or in an emergency situation.

Treatment of congenital tracheal stenosis

Congenital tracheal surgery is uncommon and few centers have enough experience to make meaningful conclusions about treatment. Short-segment congenital tracheal stenosis is treated by tracheal resection, whereas long-segment stenosis is treated by slide tracheoplasty. Tracheomalacia is treated most commonly by aortopexy if due to simple vascular compression, division of an offending vascular ring if due to a compressing or encircling ring, or by careful observation if not associated with vascular compression.

Tissue-engineered tracheal transplantation

Regenerative medicine offers new tools with which to tackle disorders for which there is currently no good therapeutic option. The trachea is an ideal organ in which to explore the clinical potential of tissue engineering because severe large airway disease is poorly managed by conventional treatments, and the success of a graft is determined only by its ability to conduct air lifelong: that is, whether it can become a sustainable biological conduit. We define the component parts of tissue engineering and review the experimental methods used to produce airway implants to date, including a recent successful, first-in-man experience.

Successful Treatment of Tracheal Stenosis with Slide Tracheoplasty after the Failure of Resection with End-to-End Anastomosis

The combined effects of inhaled irritant gases and heat in burn patients can result in the development of laryngotracheal strictures. Several factors could adversely affect the development of tracheal stenosis and cause the growth of granulation tissue. Yet the current treatment options for this condition are limited because of the paucity of case reports. We report here on a case of a patient who experienced recurrent upper tracheal stenosis after an inhalation injury. She displayed repetitive symptoms of stenosis even after several laryngomicrosurgeries and resection with end-to-end anastomosis. Finally, 5 yr after the burn injury, slide tracheoplasty was successfully performed and the postoperative check-up findings and the increased airway volume seen on imaging were all satisfactory.

Long segment congenital tracheal stenosis in twins successfully treated by slide tracheoplasty

Long segment congenital tracheal stenosis (LSCTS), associated with complete tracheal rings, is a rare condition, difficult to manage and historically associated with high mortality rate. We report two pairs of identical twins all affected by LSCTS successfully treated by sliding tracheoplasty. All had severe respiratory distress. Three infants had left pulmonary artery (LPA) sling and one intra-cardiac malformation. Slide tracheoplasty was done under cardiopulmonary bypass, and cardiovascular malformations were corrected at the same time. One child needed plication of paralyzed right hemi-diaphragm and another distal tracheal Palmaz stent insertion due severe tracheobronchomalacia. All children are doing well during 6 months follow-up. Slide tracheoplasty seems to produce the same good early results in twins as for singletons with LSCTS.