The use of expandable metallic airway stents for tracheobronchial obstruction in children

Surgical treatment for severe pediatric tracheobronchomalacia: the 20-year experience of a single center

OBJECTIVE

In children with tracheobronchomalacia, surgical management should be reserved for the most severe cases and be specific to the type and location of tracheobronchomalacia. The goal of this study is to describe the presentation and outcomes of children with severe tracheobronchomalacia undergoing surgery.

METHODS

Retrospective case series of 20 children operated for severe tracheobronchomalacia at a tertiary hospital from 2003 to 2023. Data were collected on symptoms age at diagnosis, associated comorbidities, previous surgery, age at surgery, operative approach, time of follow-up, and outcome. Surgical success was defined as symptom improvement.

RESULTS

The most frequent symptoms of severe tracheobronchomalacia were stridor (50 %), cyanosis (50 %), and recurrent respiratory infections (45 %). All patients had one or more underlying conditions, most commonly esophageal atresia (40 %) and prematurity (35 %). Bronchoscopy were performed in all patients. Based on etiology, patients underwent the following procedures: anterior aortopexy (n = 15/75 %), posterior tracheopexy (n = 4/20 %), and/or posterior descending aortopexy (n = 4/20 %). Three patients underwent anterior aortopexy and posterior tracheopexy procedures. After a median follow-up of 12 months, 16 patients (80 %) had improvement in respiratory symptoms. Decannulation was achieved in three (37.5 %) out of eight patients with previous tracheotomy. The presence of dying spells at diagnosis was associated with surgical failure.

CONCLUSIONS

Isolated or combined surgical procedures improved respiratory symptoms in 80 % of children with severe tracheobronchomalacia. The choice of procedure should be individualized and guided by etiology: anterior aortopexy for anterior compression, posterior tracheopexy for membranous intrusion, and posterior descending aortopexy for left bronchus obstruction.

Bronchial Remodeling Following Airway Stenting in Pediatric Patients With Tracheobronchial and Congenital Heart Disease

Background

Treatment of tracheobronchial disease in medically complex infants with congenital heart disease (CHD) is often challenging. When conservative management or surgery fails or is contraindicated, airway stenting can allow for advancement of care or weaning of respiratory support.

Methods

We identified 8 cases of airway stenting with balloon-expandable coronary bare-metal stents performed at our institution between February 2019 and September 2022 to relieve conservative treatment-refractory tracheobronchial disease in pediatric patients with CHD. All patients underwent rigid microlaryngoscopy, bronchoscopy, and flexible bronchoscopy as well as computed tomography angiography.

Results

Eight patients underwent technically uncomplicated placement of balloon-expandable coronary bare-metal stents in the trachea or bronchus. Immediate improvement in respiratory parameters was noted following stent placement. Six patients were able to wean mechanical ventilation following stent placement, with a median of 2.5 days of mechanical ventilation following the procedure (range, 0-219). All stents were subsequently endoscopically removed at a median of 6.8 months (range, 0.4-16.3 months). In 6 patients, bronchoscopy after stent removal demonstrated a rounder configuration of the airway consistent with bronchial remodeling.

Conclusions

In pediatric patients with tracheobronchial and CHD, airway stenting with balloon-expandable bare-metal coronary stents relieved respiratory symptoms with minimal complications and resulted in bronchial remodeling after stent removal.

Endotracheal metallic stent removal: A novel ABC (airway balloon collapse) technique

To illustrate a previously unreported method of tracheal stent removal that appears to cause less mucosal injury we present a case of a 9-year-old Down syndrome patient with a history of tracheoesophageal fistula, brought to our attention after recurrent bouts of exacerbating cough and tracheo-bronchitis. Endoscopic examination under general anesthesia noted the presence of severe tracheomalacia with inspiratory collapse, and a 10-mm balloon expandable metallic stent (BEMS) was deployed and symptomatic improvement was noted. The initial stent was then removed to consider a definitive procedure using the typical grasping fashion with an alligator forceps and expected mucosal excoriation was noted. Due to symptom recurrence, the patient underwent placement of a second BEMS stent. Initial improvement was noted followed by recurrent episodes of respiratory distress due to granulation tissue formation and stent compression and a decision to remove the stent was made. A new method of stent removal deemed ABC (airway balloon collapse) method was utilized where an expandable airway balloon is placed outside the stent between the stent and tracheal wall and then inflated to collapse the stent, facilitating easy removal.

Surgical outcomes of absent pulmonary valve syndrome: An institutional experience

Background:

Absent pulmonary valve syndrome (APVS) is a variant of tetralogy of Fallot characterized by aneurysmal pulmonary arteries, which compresses the tracheobronchial tree, leading to respiratory symptoms. We report the mid-term outcomes of surgical correction of patients with APVS.

Subject and Methods:

A total of 27 patients underwent surgery between 2001 and 2015, and they were followed up for a mean period of 6.4 ± 4.1 years. Out of the 27 patients, 14 (51.9%) were infants. The median age at repair was 9.8 months. Preoperative intubation was required in six patients (22.2%), and 11 patients (40.7%) had symptoms of respiratory distress. The pulmonary valve was replaced with a valved conduit in 15 patients (55.6%), monocusp valve in 6 patients (22.2%), and a transannular patch in 6 patients (22.2%). Reduction pulmonary arterioplasty was done in all patients.

Results:

The overall 10-year survival was 82.1%. There was 81.1% overall freedom from re-intervention at 10 years. No statistically significant difference was found in 10-year survival (P = 0.464) and reoperation rates (P = 0.129) between valved conduit, monocusp, or transannular patch techniques. Older children had statistically significantly longer survival (P = 0.039) and freedom from re-intervention (P = 0.016) compared to infants. Patients without respiratory complications had 100% 10-year survival and 93.3% freedom from reoperation at 10 years compared to 55.6% and 60.1%, respectively, for patients with respiratory complications.

Conclusion:

There has been improvement in surgical results for APVS over the years. However, it still remains a challenge to manage infants and patients with persistent respiratory problems.

Esophageal Trachea, a Unique Foregut Malformation Requiring Multistage Surgical Reconstruction: Case Report

Abnormal connections between the esophagus and low respiratory tract can result from embryological defects in foregut development. Beyond well-known malformations, including tracheo-esophageal fistula and laryngo-tracheo-esophageal cleft, rarer anomalies have also been reported, including communicating bronchopulmonary foregut malformations and tracheal atresia. Herein, we describe a case of what we have called "esophageal trachea," which, to our knowledge, has yet to be reported. A full-term neonate was born in our institution presenting with a foregut malformation involving both the middle esophagus and the distal trachea, which were found to be longitudinally merged into a common segment, 3 cm in length, located just above the carina and consisted of esophageal tissue without cartilaginous rings. At birth, the esophagus and trachea were surgically separated via right thoracotomy, the common segment kept on the tracheal side only, creating a residual long-gap esophageal atresia. The resulting severe tracheomalacia was treated via simultaneous posterior splinting of such diseased segment using an autologous pericardium patch, as well as by anterior aortopexy. Terminal esophagostomy and gastrostomy were created at that stage due to the long distance between esophageal segments. Between ages 18 and 24 months, the patient underwent native esophageal reconstruction using a multistage traction-and-growth surgical strategy that combined Kimura extra-thoracic esophageal elongations at the upper esophagus and Foker external traction at the distal esophagus. Ten months after esophageal reconstruction, prolonged, refractory, and severe tracheomalacia was further treated via anterior external stenting using a semitubular ringed Gore-Tex® prosthesis, through simultaneous median sternotomy and tracheoscopy. Currently, 2 years after the last surgery, respiratory stabilization, and full oral feeding were stably achieved. Multidisciplinary management was crucial for assuring lifesaving procedures, correctly assessing anatomy, and planning for multiple sequential surgical approaches that aimed to restore long-term respiratory and digestive functions.

Long-term management and outcomes of tracheobronchial stent by flexible bronchoscopy in infants <5 kg: A 13-year single-center experience

BACKGROUND

Tracheobronchial (TB) lumen narrowing may require prolonged positive-pressure ventilation, endotracheal tube intubation or even surgical interventions. Therapeutic flexible bronchoscopy (TFB) of balloon-expandable metallic stent (BEMS) placement and subsequent forceps, laser and balloon dilatation management might be less invasive and helpful. This study aimed to analyse the placement, follow-up management with TFB and long-term outcomes in small infants with BEMS.

METHODS

This retrospective study reviewed the medical records and associated TFB videos of infants with a maximum body weight (BW) of 5.0 kg who had TB BEMS placement from January 2005 to December 2017 at our institution. All TFB procedures were supported with a novel noninvasive ventilation, nasopharyngeal oxygen with intermittent nose closure and abdominal compression.

RESULTS

Forty-one BEMSs were placed in 24 infants. The mean BW and mean age were 4.0 ± 0.7 kg and 4.9 ± 2.4 months, respectively. There were 20, 8 and 13 stents located in trachea, carina and main-stem bronchi, respectively. Seven infants with 13 stents died without obvious stent-related mortality. Seven stents in five infants were successfully retrieved by rigid endoscopy (RE). At placement, the diameters of 28 tracheal and 21 bronchial stents were 7.5 ± 1.1 (4-10) and 5.4 ± 0.9 (4-8) mm, respectively. These implanted BEMSs could be gradually and significantly (p < 0.01) expanded. At the end of the follow-up period, all the remaining 21 stents in 12 infants were functional. The diameters of the 14 remaining tracheal and 13 remaining bronchial stents were 9.6 ± 2.0 (8-14) and 7.2 ± 1.4 (4-10) mm, respectively.

CONCLUSION

BEMSs are practical and effective in selected small infants with benign TB narrowing and can be safely implanted and managed with TFB, and finally retrieved by RE.

Surgical management of suprastomal tracheal collapse in children

OBJECTIVE

Suprastomal collapse is a complication of pediatric tracheotomy with a potential impact on decannulation success. The aim of this study was to review the experience in the management of pediatric suprastomal collapse in a tertiary-care center, detailing the surgical technique employed.

METHODS

This study included 12 tracheotomised children with the diagnosis of suprastomal collapse in the last 5 years. All patients of the study underwent surgical intervention to manage suprastomal collapse to achieve tracheotomy decannulation. The surgical procedure entailed dissection of the pre-existing tracheotomy tract down to the trachea, then excision of the tract flush with the anterior tracheal wall. The tracheal opening was closed transversely with 3-4 interrupted absorbable sutures placed in craniocaudal direction.

RESULTS

At the end of treatment all patients were decannulated successfully. No intraoperative complications were reported. Minor postoperative complications were reported in 3 children in the form of mild surgical emphysema (n = 2) and wound infection (n = 1). Those patients were successfully managed conservatively.

CONCLUSION

This technique is a simple and effective procedure enabling immediate decannulation with very low morbidity. In a long term follow up period, no recurrence has been reported and all patients returned to their usual quality of life.

Experimental use of new absorbable tracheal stent

BACKGROUND/PURPOSE

Silicone and metallic stents are not effective in children with tracheobronchial stenosis or tracheomalacia. Herein, we aimed to evaluate the clinical manifestations and histological reaction of rabbit trachea to the presence of a new poly(lactic-co-glycolic acid) with polyisoprene (PLGA/PI) polymer absorbable stent.

METHODS

Fourteen adult white rabbits (weight, 3.0-3.5kg) were randomly assigned to three groups: Group I (n=6): PLGA/PI spiral stent; Group II (n=6): PLGA/PI fragment; and Group III (n=2): controls. After a longitudinal incision on three cervical tracheal rings, the stents and fragments were inserted into the trachea and fixed onto the lateral wall with nonabsorbable sutures.

RESULTS

The stented group showed significantly more stridor at rest (p=0.0041), agitation (p=0.014), and use of accessory muscles (p=0.0002) and required more emergency endoscopies than the fragment group. Further, it showed significantly more remarkable histological inflammatory damage than the fragment and control groups (p=0.002).

CONCLUSIONS

The new PLGA/PI polymeric stent implanted into the trachea of rabbits caused more clinical manifestations and histologically verified inflammatory reaction than the PLGA/PI polymeric fragment. Future studies should be aimed at reducing the stent-wall thickness.

Pediatric airway surgery

Pediatric airway surgery is a challenging field in pediatric surgery. Laryngotracheal stenosis has a variety of congenital and acquired conditions that require precise assessment and tailored treatment for each individual patient. About 90% of acquired conditions are represented by subglottic stenosis (SGS) resulting as a complication of tracheal intubation. Congenital tracheal stenosis (CTS) is a rare and life-threatening malformation, usually associated with complete tracheal rings along a variable length of the trachea. Tracheomalacia (TM) is a process characterized by flaccidity of the supporting tracheal cartilage, widening of the posterior membranous wall, and reduced anterior-posterior airway caliber. The clinical presentation can vary from almost asymptomatic patients to near fatal airway obstruction. There is considerable variation in both the morphologic subtypes and the prognosis of pediatric airway. The patients are divided into three clinical groups (mild, moderate, and severe). A further division was proposed according to the presence or absence of associated anomalies. The definitive diagnosis of pediatric airway was made by means of rigid bronchoscope and computed tomography scan with three-dimensional reconstruction (3D-CT). Rigid bronchoscopy and 3D-CT confirmed the diagnosis in all the cases. Other associated anomalies include congenital heart disease, vascular anomalies, and BPFM (maldevelopment of aerodigestive tract). After definitive diagnosis of pediatric airway lesions, surgical intervention should be considered. Surgical strategy was presented on each lesion.

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.

Biodegradable polydioxanone stent as a new treatment strategy for tracheal stenosis in a rabbit model

PURPOSE

Congenital tracheal stenosis (CTS) is a rare condition and difficult to treat. Slide tracheoplasty has unsatisfactory outcomes for severe neonatal symptomatic CTS. This study evaluated the use of biodegradable polydioxanone stents (BD stent) in a rabbit model of CTS.

METHODS

Tracheal stenosis was induced in female Japanese white rabbits, 9-10weeks old, by direct scraping of the tracheal mucosa with a nylon brush following transverse incision of the trachea (control group, n=4). Seven days later, we incised the trachea again and inserted a BD stent (15×5mm) into the trachea (stent group, n=4). Arterial blood gas analysis was performed twice weekly for 1month after the procedure.

RESULTS

In the control group, respiratory acidosis arising from ventilatory failure was observed on postoperative days 7-10. Rabbits were sacrificed at 11.5days after scraping. Severe tracheal stenosis resulting from inflammatory granulation was detected in the scraped region in all rabbits. In the stent group, arterial blood gas analysis was normal at 28days after stent insertion. The BD stent maintained patency of the tracheal lumen and prolonged survival for 1month.

CONCLUSIONS

The use of BD stent represents a promising new treatment method for tracheal stenosis.

Use of the Palmaz Stent in the Treatment of Severe Tracheomalacia

To present our experience with the use of the Palmaz stent in treating cases of severe, life-threatening tracheomalacia, and to report our experience with the use of tracheal stents in patients who have concomitant tracheotomies, we performed a retrospective study in a tertiary-care children's hospital. Nine patients with multiple congenital anomalies including severe tracheomalacia required placement of a Palmaz stent to prolong life. The congenital anomalies included congenital heart disease, congenital lung disease, meningomyelocele, laryngotracheoesophageal cleft, and tracheoesophageal fistula. Three of the patients had concomitant tracheotomies. Each patient had placement of one or more Palmaz stents in the trachea and/or bronchus. Four patients died, and 5 patients are still alive. Three of the 4 patients who died had concomitant tracheotomies and died of complications associated with significant tracheal hemorrhage. The fourth died of pulmonary complications following repeated episodes of pneumonia. None of the 5 patients who are still alive had a concomitant tracheotomy. The Palmaz stent is a useful tool for treating life-threatening tracheomalacia as a final resort in this difficult patient population; however, the use of these stents may lead to subsequent hemorrhage and death, especially in patients with tracheotomies, so their use must be carefully considered.

Pediatric tracheomalacia

Tracheomalacia (TM) is defined as an increased collapsibility of the trachea due to structural anomalies of the tracheal cartilage and/or posterior membrane. Tracheomalacia has a wide range of etiologies but is most commonly present in children born with esophageal atresia and tracheal esophageal fistula. Clinical symptoms can range from minor expiratory stridor with typical barking cough to severe respiratory distress episodes to acute life-threatening events (ALTE). Although the majority of children have mild-to-moderate symptoms and will not need surgical intervention, some will need life-changing surgical treatment. This article examines the published pediatric literature on TM, discusses the details of clinical presentation, evaluation, diagnosis, and a variety of treatments.

Tracheobronchial stents in children

Tracheobronchial obstruction is infrequent in children and still remains a challenging matter of concern. Management alternatives vary from conservative treatment to complex surgical techniques or endoscopic interventional procedures. Airway stenting in children is relatively recent and follows the trail of the experience in adult patients. Nevertheless, there are basic differences between both age groups like the benign nature of most obstructions and the small size of the pediatric airway. These specific features raise the issues of the precise role of tracheobronchial stenting in children and the selection of the most adequate device. Stents fall into four main categories according to the material they are made of: metallic, plastic, hybrid, and biodegradable. Each type has its own advantages and drawbacks so the ideal stent is not yet available. Despite increasing experience with stenting, definite clinical criteria for their use in children are yet to be established. Even so, there seems to be a basic general agreement that stents may play a role in particular clinical settings in which there are no other therapeutic options.

Initial experience with a new biodegradable airway stent in children: Is this the stent we were waiting for?

OBJECTIVE

To report our experience with a new type of biodegradable airway stent in the setting of severe tracheobronchial obstruction in children.

DESIGN AND METHODOLOGY

We conducted a retrospective and prospective (since June 2014) study of pediatric patients with severe airway obstruction treated with biodegradable stents in our institution between 2012 and 2015. The following data were collected: demographics, indication for stenting, bronchoscopic findings, insertion technique complications, clinical outcome, stent related complications, re-stenting, and time of follow-up.

RESULTS

Thirteen custom-made polydioxanone stents were placed in four infants (mean age, 4 months) with severe tracheobronchial obstruction: tracheomalacia (two patients), bronchomalacia (1), and diffuse tracheal stenosis (1). All the stents were bronchoscopically inserted uneventfully. Immediate and maintained clinical improvement was observed in every case. No major stent related complications have occurred and only mild or moderate granulation tissue was observed during surveillance bronchoscopy. Two patients required repeated stenting as expected. All the patients are alive and in a good respiratory condition with a follow-up ranging from 5 to 40 months.

CONCLUSIONS

Biodegradable airway stents seem to be safe, effective, and cause fewer complications than other types of stents. They can be an alternative to the classic metallic or plastic stents for severe tracheal stenosis or malacia in small children. More experience is needed in order to establish the definite clinical criteria for their use in pediatric patients. Pediatr Pulmonol. 2016;51:607-612. © 2015 Wiley Periodicals, Inc.

Complications of Metallic Stents in the Pediatric Airway

OBJECTIVE: Our aim was to present our experience with complications caused by placement of metallic stents in the pediatric airway.

DESIGN AND SETTING: We conducted a retrospective study of the medical records of patients with complications resulting from metallic stent placement, managed by the senior authors between 1993 and 2002.

RESULTS: Nine children had complications associated with the placement of metallic airway stents. Of these, 8 children required stent removal. Granulation tissue and tracheal stenosis were seen in all 7 children with long standing stent placement. There was 1 stent death in this series.

CONCLUSIONS: Metallic airway stents can cause significant complications in the pediatric airway. These complications may supersede the airway compromise that necessitated their initial placement. As such, metallic stent placement should be approached with caution. The likelihood and severity of complications increase with time, as do the difficulties encountered upon removal. The proportion of patients in whom metallic stents may be placed “permanently” without complications is not known. Therefore we recommend that metallic airway stents be considered a temporizing measure of limited duration.

Management of tracheobronchial obstruction in infants using metallic stents: long-term outcome

INTRODUCTION

Tracheobronchial obstruction, although uncommon in the pediatric age group, remains a challenging problem. We review the long-term outcome of endoscopic metallic stenting in infants with tracheobronchial obstruction.

MATERIALS AND METHODS

Medical records of all pediatric surgical patients who underwent tracheobronchial metallic stenting in our center were reviewed retrospectively from 1996 to 2014. Patients' demographic data, including etiology, associated anomalies and nature of obstruction were reviewed. Outcome measures include complications such as re-stenosis, granulation tissue, stent migration, fractured stent, maximal tracheal diameter achieved, weaning of ventilator and growth at interval follow-up.

RESULTS

Twelve balloon-expandable metallic stents were placed in the trachea (n = 10) and/or bronchi (n = 2) of 5 patients with a median age of 13 months (range 5-30 months). Etiology of the airway obstruction included congenital tracheal stenosis (n = 4), giant cervical and superior mediastinal lymphatic malformation with tracheobronchomalacia (n = 1). Seven complications were reported (3 patients developed granulation tissue, 2 patients had re-stenosis, 1 stent migrated, 1 stent fractured). All patients survived and were in good condition with a median follow-up of 16 years (range 11-18 years). Three patients weaned off ventilator and oxygen.

CONCLUSIONS

Endoscopic stenting with metallic stent has satisfactory long-term outcome in treating infants with tracheobronchial obstruction.

Decreased granulomatous reaction by polyurethane-coated stent in the trachea

BACKGROUND

Reducing granulomatous reaction for stent implantation is important for the treatment of tracheobronchomalacia because formation of granuloma leads to refractory complication causing further respiratory distress. The purpose of this study was to clarify granulomatous reaction of newly innovated coated stents compared to non-coated metal stents.

METHODS

Materials and animal experiments were performed using the newly invented metallic stent (laser-cut stainless steel with a coating of polyurethane). In the materials experiment, the correlation between the holding force and deformity was tested by a compressor. In the animal examination, coated stents were orally implanted into the trachea in five rabbits, while non-coated stents were implanted in another five rabbits. After 3 weeks' observation, the inner diameter was measured by 3-D computed tomography, and the number of granulation tissues was counted by bronchofiberscope. Histological investigation followed in both groups.

RESULTS

In the materials experiment, new stents demonstrated a holding force similar to stainless steel stents. In the animal experiment, no difference was found in the inner diameter of the coated and non-coated stent groups (5.70 ± 0.17 vs 5.60 ± 0.27, P = 0.07). However, the number of granulation tissues was higher in non-coated stents than in coated stents (1.60 ± 0.55 vs 0.40 ± 0.55, P < 0.01). Histological investigation showed direct attachment of metal to the tracheal wall around the non-coated stents where epithelial structure was destroyed, while tracheal epithelia were preserved in the group of coated stents.

CONCLUSIONS

The new polyurethane-coated metallic stent maintains enough holding force, and reduces histobiological reaction to foreign bodies in this experiment.

Balloon tracheoplasty as initial treatment for neonates with symptomatic congenital tracheal stenosis

Neonates with congenital tracheal stenosis (CTS) sometimes develop respiratory distress and may be difficult to intubate. We used balloon tracheoplasty with a rigid bronchoscope for emergency airway management in neonates with symptomatic CTS. Herein, we describe the balloon tracheoplasty procedure and the early outcomes following its use as the initial treatment of neonatal symptomatic CTS. We performed a retrospective analysis of five neonates with CTS who were initially treated with balloon tracheoplasty at our institution from January 2010 to December 2013. Five patients with a mean birthweight of 2,117 g were treated during the study period. Of these, four developed respiratory distress after birth, and all patients had difficult intubations. In all five patients, definitive diagnosis of CTS was made by rigid bronchoscopy and 3-dimensional reconstruction scan. A total of nine balloon dilatations were performed in five patients. Following balloon tracheoplasty, two patients were extubated, one was extubated after resection and end-to-end anastomosis following initial balloon dilatation, and one remained hospitalized with tracheostomy for tracheomalacia. The remaining patient died from tracheal bleeding associated with congenital heart disease. Although our sample size was small, balloon tracheoplasty is a potentially effective initial treatment for selected cases with neonatal symptomatic CTS.

Interventional pulmonology procedures in the pediatric population

INTRODUCTION

Advanced training in interventional pulmonology (IP) includes a multidisciplinary approach to a wide variety of pathologic conditions affecting different age groups. The role of the interventional pulmonologist in the pediatric patient population has not been described. We report our experience of the care of pediatric patients by IP at an academic institution.

METHODS

A retrospective review of inpatient and outpatient IP procedures from 2008 to 2011 was performed. All patients' less than 21 years of age at the time of their procedure were identified. Data regarding age, procedure performed, pre-operative diagnosis, results, and complications were collected.

RESULTS

Thirty-five patients younger than the age of 21, with 14 of these patients being under the age of 18, were identified. Fifty-six procedures were performed on the entire cohort, 30 as inpatient procedures and 26 as outpatient procedures. There were no deaths or major complications related to any procedure.

DISCUSSION

We identified a cohort of pediatric patients that were able to successfully undergo diagnostic and therapeutic procedures under the direction of an experienced IP team. Cases included the evaluation and management of both malignant and benign complex airway and pleural diseases. There was no major morbidity or mortality related to our procedures, demonstrating an ability to safely evaluate and manage complex airway and pleural disease in the pediatric population.

Long-term outcomes of congenital tracheal stenosis treated by metallic airway stenting

AIM

Congenital tracheal stenosis is an obstructive airway lesion that often presents as a life-threatening emergency. We had introduced the balloon dilatation and placement of the expandable metallic airway stent as a therapeutic option, and this study aimed to clarify the long-term outcomes in pediatric patients.

METHODS

A retrospective review of five infants in whom balloon expandable metallic airway stents (10-40 mm long and 6-8mm in diameter) were inserted in 1997 to 2000 was conducted.

RESULTS

There was an immediate improvement of respiratory obstruction in all five infants (aged 7 days to 12 months) with four weaned from ventilation. One child died after 9 months of palliative treatment. In all inflammation and granulation tissue developed over the stents, but this could be managed by scraping or balloon compression. Metallic stents have been in place a mean of 12 years (range 6 months to 13 years) after insertion without other complications. Four children are alive and well with their stents in place. Recently, an attempt to remove the stent was done in two patients who showed dyspnea on exertion. They underwent tracheoplasty following successful complete removal of metallic stent using cardiopulmonary bypass.

CONCLUSION

Use of expandable metallic airway stents following balloon dilatation can be left for long periods to relieve tracheal obstruction. Development of granulation tissue is a major treatable complication. Removal of the stent was safely completed by open surgical intervention using a cardiopulmonary bypass. The airway stent may provide an important therapeutic option in selected cases with congenital tracheal stenosis.

Successful management of congenital bronchial stenosis using an expandable stent

Congenital bronchial stenosis is a very rare cause of neonatal dyspnea. Surgical management remains challenging in small children. We report successful implantation of a bronchial stent in a 3-month-old female infant presenting with congenital right bronchial stenosis and 18 months of follow-up. Use of stents in children remains controversial because of the problem of size mismatch as the child grows. Nevertheless, expandable stent implantation could be an interesting alternative to complex surgery for localized bronchial stenosis in neonates.

Cryorecanalization of an obstructed bronchial stent in a 12-year-old boy

We report a 12-year-old boy who underwent stent implantation into the left main bronchus at the age of 9.5 years for palliation of severe bronchial stenosis. He had developed complete obstruction of the stent by granulation tissue resulting in respiratory deterioration and the requirement of mechanical ventilation. The stent obstruction was treated at the age of 11.5 years by cryorecanalization. In this technique, cooling of the tip of the cryoprobe is used to induce adherence of the obstructing tissue allowing the subsequent removal of tissue particles by retraction of the probe. Under general anesthesia, a miniaturized cryoprobe was advanced via the working channel of a flexible bronchoscope. Repeat maneuvers of freezing and retraction resulted in complete recanalization of the stent. Repeat bronchoscopies 4 and 12 weeks later revealed recurrent formation of some granulation tissue which was removed by repeat cryorecanalization. Seven months after the initial procedure there was a complete patency of the stent. According to our experience, cryorecanalization is a safe and effective alternative for the treatment of stent obstruction by granulation tissue. Due to the introduction of a miniaturized probe, this method is well applicable in children since it can be performed via the working channel of a flexible pediatric bronchoscope.

Flexible fiberoptic bronchoscopy--a bedside technique for neonatologists

BACKGROUND

Flexible fiberoptic bronchoscopy (FFB) is an under-used technology in neonates, mostly performed by external consultants from either pulmonology or otolaryngology. Modern ultra-thin scopes offer the neonatologist new diagnostic and therapeutic opportunities at the bedside.

OBJECTIVE

To describe the diagnostic value, therapeutic potential, and safety profile of FFB in neonates when performed by neonatologists as a bedside procedure.

METHODS

This was a retrospective case series that included 19 term and preterm infants who underwent FFB in two Neonatal Intensive Care Units (NICU).

RESULTS

Twenty-five procedures were performed for the following indications: suspected airway pathology (15); BAL (8), noisy breathing (4), aid to difficult endotracheal intubation (1), investigation for failure of weaning from ventilation (6), and evaluation of tracheotomy or endotracheal tube patency (5). Thirteen procedures had more than one indication. Airway pathology was observed in 15 of 25 (60%) procedures. Treatment of atelectasis was successful in 7 of 10 cases. BAL culture results influenced antibiotic therapy in 5 of 10 cases (50%). No procedure-related mortality occurred. One serious adverse event (1/25, 4%), namely bilateral pneumothorax occurred 1 h after FFB.

CONCLUSIONS

FFB is a useful and safe procedure that belongs in the neonatologists' armamentarium.

The role of endoluminal self-expanding stents in the management of pediatric tracheal stenosis

OBJECTIVE

Review of our experience in the management of pediatric tracheal stenosis using endoscopic techniques and self-expanding intraluminal stents.

METHODS

Thirteen children (aged 1 week to 14 years) with various causes of tracheal stenosis were treated. A total of 15 stents were used, 13 self-expanding nitinol stents and 3 silicone self-expanding stents. Follow-up ranged from 6 month to 8 years.

RESULTS

There were no stent related mortalities. Serious complications occurred in 4 patients [30.7%] but all were managed successfully. The most frequent problem was granulation tissue formation. Patient follow-up ranged from 6 months to 8 years. In the short-term (18-24 months) 12 stents remained patent and functional. On the longer term (5 years) 3 stents required removal, one required replacement and another resulted in stenosis.

CONCLUSION

Endoluminal stenting can have an increasing role in the management of selected cases pediatric tracheal stenosis with acceptable morbidity and stable long-term results.

Aortic pseudoaneurysm in a child with a left mainstem bronchial stent

OBJECTIVE

To report a case of aortic pseudoaneurysm in a child with a metallic bronchial stent.

DESIGN

Case report and literature review.

SETTING

Pediatric intensive care unit at a freestanding tertiary children's hospital.

PATIENT

A 12-yr-old boy with a left mainstem bronchomalacia managed with a metallic stent presenting with bleeding from his tracheostomy.

INTERVENTIONS

Emergent flexible tracheobronchoscopy, computed tomography angiogram.

MEASUREMENTS AND MAIN RESULTS

Discovery of a pseudoaneurysm of the descending thoracic aorta adjacent to the bronchial stent.

CONCLUSIONS

We report the first case of an aortic pseudoaneurysm in association with a bronchial stent in a child.

Aortopexy in Infants and Children—Long-term Follow-up in Twenty Patients

BACKGROUND

Aortopexy has become an established surgical procedure for the treatment of tracheomalacia (TM) in infants and children. The aim of the present study was to evaluate the clinical outcome and respiratory function after aortopexy in the long term.

METHODS

Between 1992 and 2006, 20 patients (6 female, 14 male) with TM were treated by bronchoscopically monitored pexis of the aorta via a right anterior thoracotomy. Patient age ranged from 4 months to 11 years (mean: 29 months). Five infants had previous surgery of esophageal atresia or tracheo-esophageal fistulae, and five other patients were operated on for gastroesophageal reflux. Postoperative tidal expiratory flow (TEF25%) was compared to age-related values.

RESULTS

Mean follow-up was 7.8 years (range: 13 months to 10.7 years). There was no early or late mortality. Most patients (n = 16) showed immediate and permanent relief of symptoms. Compared to corresponding age groups, median TEF25% was slightly but not significantly decreased after aortopexy (p = 0.15). In one patient a re-aortopexy was necessary. Another patient experienced recurrent tracheo-esophageal fistula 3 years after aortopexy.

CONCLUSIONS

The bronchoscopically guided aortopexy is an efficient and simple method in the surgical treatment of TM in infants and children. The follow-up data in this series of 20 patients showed improvement of respiratory function and permanent relief of symptoms in the long term.

Thoracoscopic aortopexy for primary tracheomalacia in a 12-year-old

Aortopexy is the therapeutic modality of choice for severe primary tracheomalacia. The thoracoscopic approach has been used with good results in infants and toddlers, but little information exists on the use of aortopexy in older children. We present the case of a boy with a lifelong history of refractory, a steroid-dependent reactive airway disease, and who was found to have severe primary tracheomalacia. He subsequently underwent thoracoscopic aortopexy with immediate resolution of the tracheomalacia as demonstrated by serial bronchoscopy and long-term resolution of his clinical respiratory symptoms at 1 year.

Experimental Repair of Tracheal Defects Using a New Biodegradable Membrane

BACKGROUND

The increasing number of newborns requiring intubation and artificial ventilation in the sophisticated premature and intensive care units of recent years has been followed by a concomitant increase in the number of children who develop tracheal stenosis as a sequela of prolonged intubation, with a consequent increasing need for tracheal surgical repair. This study was designed to evaluate the ability of a new tissue-engineered biodegradable membrane to tightly seal significant tracheal defects.

MATERIALS AND METHODS

A surgically induced tracheal defect of 10 x 5 mm was repaired in rabbits using the NVR-7 membrane--a cross-linked copolymer derived from a dextran sulphate gelatin construct. The unique features of this new membrane are biocompatibility, biodegradability, elasticity, and suturability, as well as a smooth sterilization process. The animals were sacrificed and the tracheas examined at 2, 3, 4, and 8 weeks postsurgery.

RESULTS

Seven (7) of 8 rabbits undergoing tracheal surgery survived, with a tight air seal and an almost normal airway. Macroscopic and microscopic studies of the removed specimens showed variable degrees of immunogenic reaction toward the membrane. In the long term (2-3 months), a complete regeneration of all the tracheal layers occurred, simulating the original structure and orderly arrangement of a normal trachea.

CONCLUSIONS

The surgical correction using the above membrane enabled the operated animals to overcome any respiratory distress, adequately correcting the induced tracheal defect. From this experimental study, we conclude that the new NVR-7 membrane appears to be a promising therapeutic adjunct in the treatment of patients with tracheal defects.

Congenital anomalies of the esophagus

Normal anatomy, embryology, and congenital anomalies of the esophagus are discussed in this article. The classification, epidemiology, embryology, diagnosis, and management, including outcome following repair of esophageal atresia with or without an associated tracheoesophageal fistula, are described. The diagnosis and management of less common anomalies, such as congenital esophageal stenosis and congenital esophageal duplication, are outlined.

Surgical Treatment of Absent Pulmonary Valve Syndrome Associated With Bronchial Obstruction

BACKGROUND

Absent pulmonary valve syndrome (APVS) is a relatively rare anomaly that is usually associated with a ventricular septal defect and a restrictive pulmonary annulus with severe pulmonary regurgitation. The to-and-fro flow across the right ventricular outflow tract produces enormously dilated and pulsatile pulmonary arteries (PAs) that cause severe respiratory distress and tracheomalacia by compression of the trachea and primary bronchi. This retrospective study summarizes our 20-year experience of surgical treatment in patients with APVS.

METHODS

Between 1984 and 2005, 20 patients underwent repair of APVS using a valved conduit (n = 9), transannular patch (TAP) insertion alone (n = 5), or TAP with monocusp valve (n = 6) with PA reduction arterioplasty. Median age was 7 months (range, 6 days to 9 years).

RESULTS

There were one perioperative and two late deaths. All deaths were related to airway complications. Survival was 90% at 1 year and 85% at 10 and 15 years. In a multivariate analysis only preoperative ventilator dependency was associated with a worse outcome (p = 0.02). Follow-up was available in 18 operative survivors (mean follow-up, 7.3 +/- 5.2 years). Six patients (33%) underwent reoperation for pulmonary valve incompetence and right ventricular dysfunction. Three patients (17%) had episodic bronchospasm of mild to moderate severity that were responsive to sympathomimetic bronchodilators.

CONCLUSIONS

Morbidity associated with perioperative respiratory complications and ventilator dependency due to underlying tracheobronchomalacia is an important problem in patients with APVS. These infants may require multiple hospitalizations for recurrent respiratory infections secondary to their tracheobronchomalacia. Complete repair with a valved conduit and reduction pulmonary arterioplasty at the onset of symptoms and a definitive diagnosis is our procedure of choice for infants with APVS. With this approach, the airway can be optimized to give the best patient outcome.

DRUG-ELUTING BIORESORBABLE STENTS FOR VARIOUS APPLICATIONS

A stent is a medical device designed to serve as a temporary or permanent internal scaffold to maintain or increase the lumen of a body conduit. Metallic coronary stents were first introduced to prevent arterial dissections and to eliminate vessel recoil and intimal hyperplasia associated with percutaneous transluminal coronary angioplasty. The stent application range has expanded as more experience was gained, and encouraging results have been obtained in the treatment of vascular diseases. Stents are currently used for support of additional body conduits, including the urethra, trachea, and esophagus. The rationale for bioresorbable stents is the support of a body conduit only during its healing process. The stent mass and strength decrease with time, and the mechanical load is gradually transferred to the surrounding tissue. Bioresorbable stents also enable longer term delivery of drugs to the conduit wall from an internal reservoir and abolish the need for a second surgery to remove the device. The present review describes recent advances in bioresorbable stents, focusing on drug-eluting bioresorbable stents for various applications. Controlled release of an active agent from a stent can be used to enhance healing of the surrounding tissues, to increase the implant's biocompatibility, as well as to help cure certain diseases. Because a lot of research in this field has been done by us, examples for these functions are described based mainly on developments in our laboratories.

Outcomes of Tracheobronchial Stent Placement for Benign Disease

PURPOSE

To retrospectively determine long-term outcomes in patients who have undergone tracheobronchial stent placement for benign diseases.

MATERIALS AND METHODS

Institutional Review Board approval was obtained for this retrospective HIPAA-compliant study, with waiver of informed consent. Forty patients (22 female, 18 male; mean age, 52.0 years) who were treated with metallic airway stents for benign stenosis were identified from an interventional radiology database. Causes of airway stenosis included transplant stricture (n = 13), tracheal tube injury (n = 10), inflammation (n = 6), tracheobronchomalacia (n = 4), infection (n = 3), and extrinsic compression (n = 4). Follow-up, which ranged from 6 to 2473 days, was performed by means of chart review for deceased patients and by means of clinical visit or telephone interview for surviving patients. Survival, primary patency, and assisted patency were estimated by using the Kaplan-Meier product limits method.

RESULTS

Initial technical success was achieved in all cases. Symptomatic improvement was present in 39 of 40 cases. At review, 15 patients were alive and had clinical improvement, 18 had died of comorbid causes, one had died of uncertain causes, three had undergone subsequent airway surgery, two had undergone airway stent retrieval, and one was lost to follow-up. Survival at 1, 2, 3, 4, 5, and 6 years was 79%, 76%, 51%, 47%, 38%, and 23%, respectively. Loss of primary patency was most rapid during the 1st year. With repeat intervention, assisted patency was 90% at 6.8 years.

CONCLUSION

Attrition of tracheobronchial stent patency is most rapid during the 1st year, and a high rate of long-term patency can be achieved with secondary interventions. Metallic airway stents are well-tolerated and useful adjuncts for management of select benign tracheobronchial stenoses.

Placement of Covered Retrievable Expandable Metallic Stents for Pediatric Tracheobronchial Obstruction

PURPOSE

To evaluate the safety and clinical effectiveness of placement of covered retrievable expandable metallic stents in seven children with tracheobronchial obstruction.

MATERIALS AND METHODS

Using bronchoscopic and fluoroscopic guidance, stent placement was performed in seven children (median age, 12 y; range, 2 mo-14 y). The stents were electively removed 6 months after placement or whenever there were symptom-producing complications. During the follow-up period, technical and clinical success, complications and related reinterventions, and long-term prognosis were retrospectively evaluated.

RESULTS

Stent placement was technically successful for a total of eight stents in all seven patients. Stent removal was also successful for six stents in five patients; two stents were removed electively 6 months after placement, and four stents were removed due to symptom-producing complications. Clinical success defined as ventilator weaning, extubation, or dyspnea improvement was achieved in all patients 1 week after stent placement. A possible infection source in one stent and abundant granulation tissue caused by three stents necessitated removal of four stents in three patients. During the mean follow-up period of 18.7 months (range, 1-31 mo) after stent placement, three patients died due to the progression of underlying cardiopulmonary disease or malignancy. There were no deaths directly related to stent placement or related complications.

CONCLUSION

Although the findings were based on a small series, placement of covered retrievable expandable metallic stents seems to be safe and effective for the treatment of pediatric tracheobronchial obstruction. Ventilator weaning, extubation, or dyspnea improvement was possible in all patients after stent placement.

Dexamethasone loaded bioresorbable films used in medical support devices: structure, degradation, crystallinity and drug release

Bioresorbable polymer films containing dexamethasone (DM) were prepared using a solution processing technique. Investigation of the films focused on cumulative DM release as affected by film morphology (drug location/dispersion in the film) and degradation processes. Two film structures were studied: A-type, a polymer film with large drug crystals located on the film's surface, and B-type, a polymer film with small drug particles and crystals distributed within the bulk. The effect of the polymer's degree of crystallinity on the drug release profile was also studied. Prototypical applications of these films are biodegradable medical support devices which combine mechanical support with drug release. In most of our studied systems the drug release profile from the film is determined mainly by both drug location/dispersion in the film and the polymer's weight loss rate. All release profiles from A-type films exhibited a burst effect of approximately 30%, accompanied by a second release phase at a constant rate, whereas the release profiles from B-type films were determined mainly by the degradation profile of the host polymer, and did not exhibit any burst effect. A high degree of crystallinity is important for the current application, since good mechanical properties are required. This contributes to slower drug release rates, mainly at relatively low weight losses, whereas at high weight losses, where a porous structure is created, the crystallinity almost does not affect the rate of drug release. The shape of the porous structure that develops with degradation also affects the drug release profile from the B-type films.

Tracheal obstruction caused by an expandable metallic stent: a case of successful removal of the stent

We report a case of tracheal obstruction caused by an expandable metallic stent. A 3-month-old girl with severe tracheomalacia had a placement of a Palmaz stent. At 3 years of age, she developed progressive dyspnea. The CT scan showed tracheal obstruction caused by granulation tissue over the stent. At operation, the stent was found to have penetrated the posterior tracheal wall. Under partial cardiopulmonary bypass, the stent was removed along with the membranous wall of the trachea, and the trachea was reconstructed using slide tracheoplasty. Tracheal obstruction is one of the serious complications caused by an expandable metallic stent. Direct open approach to the trachea under cardiopulmonary bypass is thought to be a safe way to manage this problem.

Treatment of airway obstruction by metallic stents in infants and children

OBJECTIVE

The internal metallic stent is a relatively new and controversial method for the treatment of airway collapse in infants and children. The study examined the outcomes of this treatment in a large group of patients and defined clear indications for airway stenting.

METHODS

A retrospective review was conducted of 32 patients in whom 42 stents were inserted. The patients were divided into three groups with respect to the stented segment: group A, trachea (n = 14); group B, bronchi (n = 16); and group C, trachea and bronchi (n = 2).

RESULTS

In 30 cases, there was immediate improvement of respiratory obstruction, and 23 patients could be weaned, at least temporarily, from ventilation. Excessive granulation developed after the stenting in 26 patients. In 6 patients, all in group A, the granulation and inflammatory reaction generated severe airway obstruction, necessitating thoracotomy in 2 cases. One patient died of airway obstruction, and another died during the attempt to remove the stent; both were in group A. Stents placed for 2 to 72 months (mean 8.7 months) have now been removed in 11 patients. Six children are alive and well with stents in place, 2 from group A and 4 from group B. Fifteen patients died during the follow-up period; in 13 cases, death was related to the associated disease.

CONCLUSION

The use of metallic stents, especially in the trachea, is associated with a high rate of complications. Granulation tissue, which often develops after stenting, is a major concern. Removal of the stents is arduous and carries a high risk of complications. The use of stents should be restricted to the limited situations in which conventional initial therapy has failed.

A decade of using intraluminal tracheal/bronchial stents in the management of tracheomalacia and/or bronchomalacia: is it better than aortopexy?

BACKGROUND

We compared the efficacy and clinical outcomes of aortopexy versus tracheal stents in the management of tracheomalacia.

METHODS

A retrospective analysis of 25 consecutive patients undergoing aortopexy (n = 11; 8 boys, 3 girls) or tracheal stents (n = 14; 9 boys, 5 girls) between 1993 and 2003 was performed.

RESULTS

Both treatment groups, aortopexy versus stents, were comparable in their mean age of diagnosis, timing of intervention, surgical indications ("dying spell" or failed extubation), and previous underlying conditions. The operative time (190 vs 72 minutes) and blood loss (26 vs 0 mL) were significantly greater in aortopexy group (P < .01). There were no perioperative deaths in either group. Interestingly, 4 of 11 patients in the aortopexy group developed pericardial effusion (P < .01). With stents in place for a mean of 15 (range 2-41) months, 3 of 8 patients with stent removal had significant granulation tissue requiring further dilatation. No death was observed in aortopexy group, whereas 1 stent-related death and 1 cardiac arrest requiring median sternotomy occurred during stent removal in 44 and 32 months' follow-up, respectively.

CONCLUSION

Both aortopexy and tracheal stents are effective treatment modalities in the management of tracheomalacia. However, although aortopexy is associated with early perioperative complications, tracheal stents are associated with higher failure rate and more severe stent-related morbidity and mortality.

Endoscopic Removal of Metallic Airway Stents

BACKGROUND

Complications of metallic airway stents include granulation tissue formation, fracture of struts, migration, and mucous plugging. When these complications result in airway injury or obstruction, it may become necessary to remove the stent. There have been few reports detailing techniques and complications associated with endoscopic removal of metallic airway stents. We report our experience with endoscopic removal of 30 such stents over a 3-year period.

METHODS

We conducted a retrospective review of 25 patients who underwent endoscopic stent removal from March 2001 to April 2004. The patients ranged in age from 17 to 80 years (mean, 56.3 years). There were 10 male and 15 female patients. The stents had been placed for nonmalignant disease in 20 patients (80%) and malignant disease in 5 patients (20%). All procedures were done under general anesthesia with a rigid bronchoscope. Special attention was focused on the technique of stent removal and postoperative complications.

RESULTS

Thirty metallic airway stents were successfully removed from 25 consecutive patients over a 3-year period. The basic method of removal involved the steady application of traction to the stent with alligator forceps. In all cases, an instrument such as the barrel of the rigid bronchoscope or a Jackson dilator was employed to help separate the stent from the airway wall before removal was attempted. In some instances, the airway wall was pretreated with thermal energy prior to stent removal. Complications were as follows: retained stent pieces (n = 7), mucosal tear with bleeding (n = 4), re-obstruction requiring temporary silicone stent placement (n = 14), need for postoperative mechanical ventilation (n = 6), and tension pneumothorax (n = 1).

CONCLUSIONS

Although metallic stents may be safely removed endoscopically, complications are common and must be anticipated. Other investigators have described airway obstruction and death as a result of attempted stent removal. Placement and removal of metallic airway stents should only be performed at centers that are prepared to deal with the potentially life-threatening complications.

Tracheal Reaction to Three Different Intraluminal Stents in an Animal Model of Tracheomalacia

Three different internal airway stents were studied in an animal model of tracheomalacia: the Palmaz stent (Johnson & Johnson, Warren, New Jersey) and the NIR stent (Medinol Ltd., Tel Aviv, Israel)--both made of stainless steel in the form of tubular mesh--and the Nitinol stent, made of nickel-titanium formed into a spiral shape. All three stents could be adequately stabilized in the malacic tracheal segment. The Nitinol stent (Medinol Ltd., Tel Aviv, Israel) proved to be less reactive to the tracheal mucosa, demonstrated higher biocompatibility with significantly less granulation tissue formation, and showed superior radial resistance. Extraction of the Nitinol stent also proved to be much smoother. This stent may be the stent of choice in the treatment of tracheo- and bronchomalacia.

Candida Infection in a Stent Inserted for Tracheal Stenosis After Heart Lung Transplantation

Although there are many reports on the use of expandable metallic stents for treating an airway stenosis that develops after heart lung transplantation, complications from using these stents are rarely reported. We experienced a case of Candida infection in a stent that was placed to treat a tracheal stenosis after heart lung transplantation in an 11-year-old girl. The patient had progressive shortness of breath developed from the 5th postoperative week. Chest computed tomography and bronchoscopy revealed a stenosis at the level of the anastomosis. After repeated unsuccessful trials of endoscopic ablation of the granuloma, a Palmaz metallic expandable stent (8 x 30 mm) (Johnson and Johnson Interventional Systems Co, Warren, NJ) was placed, which was followed by immediate relief of the dyspnea. Bronchoscopy conducted immediately after the stent placement showed a free floating distal stent end, which needed to be followed up. The patient had been doing well for the next 9 months after stent placement when she again had shortness of breath develop. Endoscopic examination revealed an intraluminally growing fungal mass, which was particularly severe at the distal free edge of the stent. The culture yielded Candida albicans. Aggressive antifungal agents and surgical removal of the stent were planned, but the patient died 1 day after admission.

Surgical Treatment of Pulmonary Artery Sling and Tracheal Stenosis

BACKGROUND

Pulmonary artery sling is a rare vascular ring and is commonly associated with tracheal stenosis. Symptomatic newborns and infants with these complex lesions have a high mortality rate without surgical intervention. The ideal operation remains controversial, with debate focusing on the need for left pulmonary artery for reimplantation and the technique of tracheal reconstruction.

METHODS

From 1983 to 2003, 14 patients with pulmonary artery sling (mean age, 7 months; range, 6 days to 27 months) underwent repair of pulmonary artery sling alone (6 patients), tracheoplasty alone (1 patient), and pulmonary artery sling repair with tracheoplasty (7 patients). Preoperatively, 7 patients were intubated, 2 had VATER (vertebral, anal, tracheal, esophageal, and radial anomalies) syndrome, and 2 patients had agenesis of the right lung. The left pulmonary artery was reimplanted at the ductal insertion site in 13 patients. One patient had left pulmonary artery translocation. Tracheoplasty employing extracorporeal circulation consisted of autologous pericardial patch (6 patients) or slide tracheoplasty (2 patients). Six patients with pulmonary artery sling and mild tracheal stenosis required only left pulmonary artery reimplantation. Concomitant procedures included closure of atrial septal defect (4 patients), ventricular septal defect (4 patients), and shunt for Fallot's tetralogy (2 patients).

RESULTS

There were 2 hospital deaths (2 of 14;14%) from abdominal sepsis (1) and renal failure (1). Reoperations included diaphragm plication (2), tracheostomy (1), and bronchoscopy with laser resection of granulation tissue (5 patients: 2 slide, 3 pericardium). Follow-up was complete in all patients (mean, 42 months) with 1 late death from fungal sepsis. At follow-up, all left pulmonary artery anastomoses were patent by echocardiography, and no patient has required reoperation for trachea reconstruction.

CONCLUSIONS

These data demonstrate that tracheal repair is not always necessary in the presence of pulmonary artery sling; that agenesis of the right lung is not a contraindication to successful complete repair; and that simultaneous correction of intracardiac defects can be safely performed in selected patients. This study suggests that in newborns and infants, pericardial patch and slide tracheoplasty are effective methods for trachea reconstruction.

French experience of silicone tracheobronchial stenting in children

Silicone stents were inserted into the trachea or left main-stem bronchus in 14 children aged 2-69 months (median, 7 months). Indications were as follows: tracheomalacia or airway kinking (7 cases), vascular compression (5 cases), and surgically corrected congenital tracheal stenoses (2 cases). The best results were obtained in tracheomalacia. Overall, 6 cases out of 14 (43%) were considered successful, with a stent placement duration of 3-15 months (median, 7 months). Two cases were considered a technical success, although they were clinical failures. Five cases were considered failures primarily due to stent migration. A retrospective analysis of failures suggests that most of these could have been avoided by the use of larger stents. One patient died of stent obstruction. No wall erosion was observed, and the development of granulation tissue was infrequent. Endoscopic removal of the prostheses was uneventful. The biocompatibility of silicone stents appears to be better than what is reported for metal ones, although the stability of the former is less satisfactory. The present study shows the feasibility of silicone stent placement in infants. These stents should be considered as a possible therapeutic option in certain types of childhood airway disorders, although further studies are required.

Tracheobronchial intervention in children

Disorders of the major airways in children are often difficult to treat. Recent advances in interventional radiology are proving useful, for both assessment of the severity of the problem and treatment. Flexible bronchoscopy and bronchography are essential tools for diagnosis, intervention and follow-up. Echocardiography, computed tomography and magnetic resonance imaging may also be important for the evaluation of cardiovascular anomalies, which are often associated with airway obstruction. Surgery remains the first line of treatment for most congenital abnormalities of the airway and for cardiac anomalies that cause airway compression. Balloon dilatation and stenting are helpful in certain other conditions, as well as in children whose airway problem is not fully corrected by surgery. A multidisciplinary approach is required, with input from pediatric cardiothoracic surgeons, radiologists, radiographers, otolaryngologists, pulmonologists, anesthesiologists, intensivists, physiotherapists and liaison nurses.