Complete cartilage-ring tracheal stenosis associated with anomalous left pulmonary artery: the ring-sling complex

Congenital pulmonary malformations

There are many congenital anomalies of the lung, some of which have no clinical symptoms and are detected incidentally, while others, particularly in the neonatal and infant period, are recognized by their typical signs, symptoms, and radiological appearance. Some congenital lung anomalies are so important that they can cause the death of the patient if not diagnosed and treated early. Classification of congenital lung anomalies is difficult since these anomalies may be related to the airway, arterial and venous vascular system, pulmonary parenchyma, and primitive anterior intestinal anomalies from which the lung originates, and some anomalies may have several etiologic origins. In this review, all subgroups of congenital pulmonary malformations will be discussed.

Incidence of congenital tracheal stenosis in left pulmonary artery sling diagnosed by bronchoscopy

PURPOSE

Congenital tracheal stenosis (CTS) has been reported to occur in 50-65% of cases of left pulmonary artery sling (LPAS), but the exact incidence rate is unknown. This study aimed to determine the actual rate using bronchoscopy and to elucidate morphological features in computed tomography (CT) diagnosis.

METHODS

We performed a single institutional retrospective review of all patients with LPAS between January 2010 and March 2022. The percentage of complete tracheal rings in patients with LPAS was evaluated using bronchoscopy. The anteroposterior/lateral diameter ratios at the smallest and largest diameters of each CTS patient's trachea were measured on CT. The Wilcoxon signed-rank test was used to analyze the differences between the two parts.

RESULTS

Fifty-two patients with LPAS were enrolled. All patients had complete tracheal rings on bronchoscopy. CT analysis of 32 patients with CTS was performed. The median anteroposterior/lateral diameter ratio at the smallest diameter was 1.05 (interquartile range [IQR] 0.95-1.15); the median ratio at the largest diameter was 0.94 (IQR 0.89-0.99). There was a significant difference between the two parts (p = 0.013).

CONCLUSION

CTS might be universally associated with LPAS. The circular tracheal cross-section on CT might imply the existence of a complete tracheal ring.

Morphologic classification of tracheobronchial arborization in children with congenital tracheobronchial stenosis and the associated cardiovascular defects

Background

We sought to classify patients with congenital tracheal stenosis (CTS) according to tracheobronchial morphology and determine anatomic features associated with tracheobronchial anomalies (TBAs) and concurrent cardiovascular defects (CVDs).

Methods

We enrolled 254 patients who underwent tracheoplasty between November 1, 2009 and December 30, 2018. The anatomic features of the tracheobronchial tree and cardiovascular system were abstracted from bronchoscopy, echocardiography, computerized tomography, and operative reports.

Results

Four types of tracheobronchial morphology were identified: Type-1, which included normal tracheobronchial arborization (Type-1A, n = 29) and tracheal bronchus (Type-1B, n = 22); Type-2 (tracheal trifurcation; n = 49), and Type-3 (typical bridging bronchus; n = 47). Type-4 (bronchus with an untypical bridging pattern) was divided into Type-4A (involving bronchial diverticulum; n = 52) and Type-4B (absent bronchus; n = 55). Carinal compression and tracheomalacia were significantly more frequent in Type-4 patients than in the other patients (P < 0.01). CVDs were common in patients with CTS, especially in patients with Type-3 and Type-4 (P < 0.01). Persistent left superior vena cava was most common among patients with Type-3 (P < 0.01), and pulmonary artery sling was most frequent among those with Type-4 (P < 0.01). Outflow tract defects were most likely to occur in Type-1B. Early mortality was detected in 12.2% of all patients, and young age (P = 0.02), operation in the early era (P < 0.01), and bronchial stenosis (P = 0.03) were proven to be risk factors.

Conclusions

We demonstrated a useful morphological classification for CTS. Bridging bronchus was most closely linked with vascular anomalies, while tracheal bronchus was frequently associated with outflow tract defects. These results may provide a clue to CTS pathogenesis.

Successful surgical treatment of congenital tracheal stenosis combined with tracheal bronchus and left pulmonary artery sling: a 10-year single-institution experience

PURPOSE

Radical surgery for congenital tracheal stenosis (CTS) is technically demanding. CTS combined with tracheal bronchus (TB) and pulmonary artery (PA) sling is a particularly challenging condition. We herein report our successfully modified surgical techniques for CTS combined with TB and PA sling.

METHODS

Nine patients treated at our institution from July 2010 to December 2020 for CTS with TB and PA sling were enrolled. The patients' characteristics, operative results, and clinical outcomes were reviewed and analyzed retrospectively.

RESULTS

The mean age at the operation and body weight were 8.0 ± 4.4 months old and 6.5 ± 0.8 kg, respectively. The mean tracheal diameter and length of the stenotic lesion were 3.2 ± 1.0 mm (mean stenosis rate 46.2%) and 25.4 ± 4.9 mm, respectively. All cases were complicated with PA sling at bifurcation stenosis with tracheobronchomalacia. All patients underwent modified posterior-anterior slide tracheoplasty with an inverted Y-shaped incision at the bifurcation and repositioning of the PA. The mean postoperative intubation period was 25.0 ± 32.1 days. There were no major intraoperative or postoperative complications, including hypoxic-ischemic encephalopathy. The mean hospital stay was 92.2 ± 73.4 days. All patients were discharged home without tracheostomy or oxygen support.

CONCLUSION

Our slide tracheoplasty technique for CTS with TB and PA sling achieved excellent outcomes.

LEVEL OF EVIDENCE

Level IV.

Pediatric large airway imaging: evolution and revolution

Infants and children often present with respiratory symptoms referable to the airway. For these pediatric patients, airway imaging is frequently performed to evaluate for underlying disorders of the large airway. Various imaging modalities have been used to evaluate the pediatric large airway, and pediatric airway imaging techniques have continued to evolve. Therefore, clear understanding of the status and new advances in pediatric large airway imaging is essential for practicing radiologists to make timely and accurate diagnoses, which can lead to optimal pediatric patient management.

Computed tomography and magnetic resonance imaging of vascular rings and other things: a pictorial review

Compression of the airway, esophagus or both by aortic and pulmonary vessels can be caused by a variety of anatomical situations. Vascular rings are the most commonly encountered entity; however, compression can also occur from less common anomalies such as a left pulmonary artery sling or innominate artery compression. Vascular rings and other vascular compression abnormalities can be challenging to visualize and image and often require advanced imaging by CT or MRI to better understand the cause and extent of compression. Atretic vascular structures, such as the ligamentum arteriosum or atretic arch, play a key role in creating a vascular ring and do not enhance with contrast agent in a typical fashion. Despite these imaging challenges, classic and useful signs can indicate the presence or absence of a vascular ring or compression.

Fetal Diagnosis of Dextroposition, Left Pulmonary Artery Sling, Partial Anomalous Left Pulmonary Artery, and Aortic Coarctation

•LPA sling is a rare anomaly definable by fetal echocardiography. •LPA sling is frequently associated with significant respiratory morbidity and mortality. •Fetal diagnosis should prompt planning for postnatal management at a pediatric center. •We present a fetal case of dextroposition, partial LPA sling, and aortic coarctation. •Progressive dextroposition was an indicator for the presence of an LPA sling.

An essential function for autocrine hedgehog signaling in epithelial proliferation and differentiation in the trachea

The tracheal epithelium is a primary target for pulmonary diseases as it provides a conduit for air flow between the environment and the lung lobes. The cellular and molecular mechanisms underlying airway epithelial cell proliferation and differentiation remain poorly understood. Hedgehog (HH) signaling orchestrates communication between epithelial and mesenchymal cells in the lung, where it modulates stromal cell proliferation, differentiation and signaling back to the epithelium. Here, we reveal a previously unreported autocrine function of HH signaling in airway epithelial cells. Epithelial cell depletion of the ligand sonic hedgehog (SHH) or its effector smoothened (SMO) causes defects in both epithelial cell proliferation and differentiation. In cultured primary human airway epithelial cells, HH signaling inhibition also hampers cell proliferation and differentiation. Epithelial HH function is mediated, at least in part, through transcriptional activation, as HH signaling inhibition leads to downregulation of cell type-specific transcription factor genes in both the mouse trachea and human airway epithelial cells. These results provide new insights into the role of HH signaling in epithelial cell proliferation and differentiation during airway development.

Summary: A conserved autocrine role for HH signaling in tracheal epithelial cell proliferation and differentiation is revealed, suggesting potential new interventions for airway epithelial proliferation and differentiation defects.

Vascular rings

Vascular rings are congenital aortic arch anomalies that lead to compression of the trachea or esophagus. The goal of this review is to summarize our current recommendations for the management of patients with a diagnosis of a vascular ring. We review the history, classification methods, and epidemiology of the various types of vascular rings. We then propose a management strategy for the relatively new paradigm of fetal diagnosis, including the management of asymptomatic vascular rings. Finally, we finish with a review of the operative techniques and outcomes for the four main categories of vascular rings.

Pulmonary artery sling in a symptomatic newborn

Pulmonary arterial sling (PAS) is a relatively rare congenital anomaly in which left pulmonary artery branch originates abnormally from the right pulmonary artery, eventually resulting with respiratory symptoms, due to airway obstruction. In this report, we present a PAS in a neonate who showed progressive respiratory distress in the second week following delivery. At 25 days of age, the patient underwent total surgical correction of the anomaly, during which left pulmonary artery reimplantation to main pulmonary artery without the use of cardiopulmonary bypass was employed. Following an uneventful recovery, the patient was discharged eighteen days after surgery.

Long-term outcomes in children undergoing vascular ring division: a multi-institution experience

 

OBJECTIVES

Vascular rings are rare anomalies of congenital heart disease that cause respiratory and gastrointestinal symptoms. This study assessed the long-term outcomes of patients with vascular ring division.

METHODS

A multi-institution retrospective review of 371 patients with vascular rings undergoing surgical division at 3 paediatric cardiac institutions between November 2007 and October 2019 was performed.

RESULTS

The complete vascular rings consisted of a double aortic arch (24.5%), right aortic arch with left ligamentum arteriosum (36.7%) and left aortic arch, with right ligamentum arteriosum (0.5%). The incomplete vascular rings consisted of a pulmonary artery sling (22.9%), left aortic arch with aberrant right subclavian artery (15.1%) and innominate artery compression syndrome (0.3%). Respiratory symptoms included stridor (71.4%), wheezing (49.1%), coughing (31.5%), gastrointestinal symptoms included choking (12.4%), dysphagia (3.2%) and emesis (1.9%). Only one patient died after discharge, yielding a late mortality rate of 0.3% (1/360). The 10-year overall survival rate was 96.8%. Postoperative complications were reported in 51 patients, 15 of whom required reoperation. The 10-year freedom from reoperation rate was 95.9%. Follow-up was completed in 95.4% (354/371) of patients, with a mean follow-up time of 4.3 ± 2.9 years (range from 1 to 13 years). Twenty patients (5.6%) experienced residual symptoms during long-term follow-up.

CONCLUSIONS

The outcomes of vascular ring division are excellent. A Kommerell diverticulum >1.5 times the aberrant left subclavian artery origin is an operative indication for primary resection. Tracheomalacia is a risk factor for reoperation and residual symptoms, and preoperative fibrobronchoscopy is important for evaluation.

Cardiopulmonary bypass as a bridge for bronchial foreign body removal in a child with pulmonary artery sling: A case report

RATIONALE

Successful removal of an airway foreign body (FB) in some intractable cases can be very challenging, because of tracheal anomalies, unstable respiratory status of the patients, and the location of FB. The use of cardiopulmonary bypass (CPB) support for the treatment of a FB is extremely rare.

PATIENT CONCERNS

We present a case of a 39-month-old previously healthy girl who was admitted to our hospital for suspected FB aspiration (FBA). Initially, the attempt for removal of the FB by conventional bronchoscopy failed because of hypoxic intolerance.

DIAGNOSES

Bronchoscopy revealed tracheal anomalies and subsequent computed tomography angiography demonstrated the presence of a pulmonary artery sling (PAS), which confirmed the diagnosis of PAS accompanied with FBA.

INTERVENTIONS

With the assistance of CPB, multidisciplinary treatment involving the respiratory, cardiothoracic and anesthetic teams were involved and the bronchial FB was removed by flexible bronchoscopy successfully and then PAS was corrected by surgical intervention.

OUTCOMES

The patient remained asymptomatic, without shortness of breath or wheezing during the 15 months follow-up.

LESSONS

This case highlights that in a complicated case of FBA, bronchoscopy and computed tomography imaging are of great importance to achieve an accurate diagnosis, and a multidisciplinary treatment approach is essential for a satisfactory outcome. If the patient is unstable for bronchoscopy, CPB can be temporarily used in the stabilization of the patient to allow safe removal of the FB.

Lung Hypoplasia Associated With Ring-Sling Complex Is Usually Right-Sided

BACKGROUND

Pulmonary artery sling (PAS) is usually associated with long-segment congenital tracheal stenosis (LSCTS). This combination of abnormalities can also be associated with lung hypoplasia abnormalities (hypoplasia, aplasia, or agenesis). This study analyzed the association of lung hypoplasia abnormalities with combined PAS and LSCTS and its influence on its surgical outcomes.

METHODS

All patients (0 to 18 years) who underwent surgical procedures for both PAS and LSCTS from 1995 to 2019 were analyzed retrospectively for mortality, ventilation days, and intensive care unit days by dividing them into those with normal lungs (group 1) and hypoplastic lungs (group 2).

RESULTS

Included were 75 patients (30 girls [40%]), who were a median age of 5.7 months (interquartile range [IQR], 2.9-13.3 months), median weight of 5.5 kg (IQR, 4.1-7.9 kg), and had a median follow-up of 99.8 months (IQR, 54.5-152.0 months); of these, 8 patients (10.7%) had hypoplastic right lung, comprising hypoplasia in 7 (87.5%), aplasia in 1 (12.5%), and agenesis in 0 (0%). There was a significant difference in mortality (group 1, 9.0%; group 2, 50%; P = .007) but no significant difference in median ventilation days (group 1, 9.0; group 2, 9.0; P = .89) or in median intensive care unit days (group 1, 14.0; group 2, 11.5; P = .44).

CONCLUSIONS

Lung hypoplasia associated with PAS and LSCTS is usually right-sided. As a result of severe airway obstruction and single-lung physiology, there is a high requirement of preoperative cardiorespiratory support and a significant association with adverse surgical outcomes.

Influence of Fetal Diagnosis on Management of Vascular Rings

BACKGROUND

There has been an increasing frequency of fetal diagnosis of vascular rings. We compared management strategies and outcomes of infants with fetal diagnosis to those with postnatal diagnosis to inform recommendations regarding optimal management.

METHODS

Retrospective review was performed of vascular ring operations from 1/2000 to 6/2019. Standard demographic data (preoperative clinical status, timing of diagnosis, cross-sectional imaging, operative and perioperative details, and clinical outcomes) were collected. Statistical analysis was performed to compare characteristics and outcomes of fetal versus postnatal diagnosis.

RESULTS

There were 190 patients, with 15% (n=29) diagnosed prenatally. Anatomic variants were: double aortic arch (n=66, 14 fetal diagnosis), right aortic arch, aberrant left subclavian artery (n=94, 12 fetal diagnosis), circumflex aorta (n=7, 1 fetal diagnosis), and pulmonary artery sling (n=19, 2 fetal diagnoses). Increasing frequency of fetal diagnosis was noted in the past 10 years. In 2012 1/9 (11%) patients had a fetal diagnosis, in 2018 8/11 (72%) had a fetal diagnosis (p<0.001). Patients with a fetal diagnosis were significantly younger at the time of surgery (13.1 months [20.6] vs. 24.0 months [87.0], p=0.029). There was no difference in postoperative complications or length-of-stay (3 days [1] for fetal diagnosis vs. 4 days [3] for postnatal diagnosis, p=0.50).

CONCLUSIONS

Fetal diagnosis leads to the potential for expectant management of vascular ring patients. This has resulted in earlier time of intervention with no increase in postoperative morbidity. This may lead to improved long-term outcomes and potentially alter the natural history for these children.

Midterm outcomes of pulmonary artery sling repair with and without tracheoplasty

OBJECTIVE

Review a single-centre experience with pulmonary artery sling repair and evaluate risk factors for re-intervention.

METHODS

Patients with surgically repaired pulmonary artery sling at a single institution between 1996 and 2018 were retrospectively reviewed. A univariate Cox regression analysis was used to evaluate variables for association with freedom from re-intervention.

RESULTS

Eighteen patients had pulmonary artery sling repair. At operation, median age and weight were 6.9 months (interquartile range 4.1-18.1) and 9.5 kg (interquartile range 6.5-14.5), respectively. A median hospital length of stay was 12 days (interquartile range 5.8-55.3). Twelve patients (67%) had complete tracheal rings, of whom six (50%) underwent tracheoplasty (five concurrently with pulmonary artery sling repair). Airway re-intervention was required in five (83%) of the six patients who underwent tracheoplasty. One patient had intraoperative diagnosis and repair of pulmonary artery sling during unrelated lesion repair and required tracheoplasty 24 days post-operatively. One patient died 55 days after pulmonary artery sling repair and tracheoplasty following multiple arrests and re-interventions. Median post-operative follow-up for surviving patients was 6.3 years (interquartile range 11 months-13 years), at which time freedom from re-intervention was 61%. When controlling for patient and tracheal size, initial tracheoplasty was associated with decreased freedom from re-intervention (hazard ratio 21.9, 95% confidence interval 1.7-284.3, p = 0.018).

CONCLUSIONS

In patients with pulmonary artery sling, tracheoplasty is associated with decreased freedom from re-intervention. In select patients with pulmonary artery sling and complete tracheal rings, conservative management without tracheoplasty is feasible. Further study is necessary to delineate objective indications for tracheoplasty.

Tracheal development after left pulmonary artery reimplantation: an individual study

Pulmonary artery sling (PA sling) often presents as a life-threatening condition requiring urgent surgical correction. We reported 32 cases of PA sling in children who were followed up postoperatively in the past 6 years. All patients with PA slings who were admitted to the hospital from January 2012 to December 2017 and underwent surgery were retrospectively analyzed. The mean age of the 32 patients at repair was 16.97 months (range, 15 days to 128 months). Six patients required ventilator assistance for respiratory failure. All children underwent left pulmonary artery (LPA) reimplantation (n = 32), and 3 patients needed reimplantation slide tracheoplasty (n = 3) due to ventilation weaning failure. Four patients died, 27 patients survived until discharge, and 18 patients were followed up. Pulmonary computed tomography imaging and echocardiography were performed in 18 patients who were followed up. After LPA reimplantation, the tracheal carina area was significantly enlarged compared to that preoperation (p = 0.0002). In this follow-up cohort study, 75% of the patients who underwent LPA reimplantation survived until discharge. The survivors had subsequently well-developed pulmonary arteries and tracheas.

Tracheoplasty for Patients with Pulmonary Artery Sling and Tracheal Stenosis: A Meta-Analysis

We performed this meta-analysis to assess the safety and efficacy of tracheoplasty for patients with pulmonary artery sling (PAS) and tracheal stenosis. Published studies that included surgical treatment of PAS and tracheal stenosis with and without tracheoplasty were identified by searching the PubMed, EMBASE, and Cochrane Library databases until May 2020. The outcomes assessed included postoperative ventilation time, early and late mortality, and follow-up respiratory symptoms. The mean difference (MD)/risk ratio (RR) with 95% confidence intervals (CI) was estimated with a random-effects/fixed-effects model. Subgroup analysis was performed stratified by percentage of patients with tracheal rings. A total of eight studies comprising 219 patients with PAS accompanied by tracheal stenosis were included. The pooled estimates of postoperative ventilation time (MD 17.68, 95% CI 6.38 to 28.98, p < 0.01) and early mortality (RR 3.93, 95% CI 1.55 to 9.95, p < 0.01) favored the repair-only group. Late mortality (RR 1.33, 95% CI 0.48 to 3.68, p = 0.58) and respiratory symptoms (RR 1.51, 95% CI 0.50 to 4.57, p = 0.47) at follow-up showed no significant differences between the groups with repair-only and repair with tracheoplasty. The same results were found in subgroup analyses. For the surgical treatment of PAS with tracheal stenosis, repair without tracheoplasty appears to result in shorter postoperative ventilation time and lower early mortality, with no increase in late mortality or respiratory symptoms at follow-up, compared with concomitant tracheoplasty.

Congenital tracheal stenosis & associated cardiac anomalies: operative management & techniques

Congenital tracheal stenosis can lead to symptomatic airway obstruction in children and often mandates surgical correction. Over the past half-century, numerous tracheal reconstruction techniques have been developed, including tracheal resection with end-to-end anastomosis (for short-segment complete tracheal stenosis), patch tracheoplasty, slide tracheoplasty, and homograft and autograft augmentation repairs. However, operative management of congenital tracheal stenosis is often complicated by the presence of congenital heart disease, the most common of which is pulmonary artery sling. When present concomitantly, combined repair of both defects is feasible and is currently the preferred approach. Questions have been raised about the optimal timing and sequence of surgery, and some have advocated staged repair for patients with complex associated cardiac lesions. However, evidence from the past two decades suggests that concomitant repair can be performed with excellent results. The current standard of care involves the use of cardiopulmonary bypass to simultaneously repair the tracheal defect using slide tracheoplasty and all associated cardiac anomalies. Advances in operative techniques and extracorporeal circulation, progressive understanding of the pathological basis of combined congenital tracheal and cardiac disease, and a multidisciplinary approach to patient care have all contributed to the successful outcomes seen in the modern era. This article describes the combined surgical correction of tracheal stenosis and double-outlet right ventricle-tetralogy of Fallot type in an infant, provides a detailed step-by-step description for performing a slide tracheoplasty along with various other less favored tracheoplasty techniques, and reviews the current literature discussing such combined repairs.

Clinical and structural aspects of tracheal stenosis and a novel embryological hypothesis of left pulmonary artery sling

OBJECTIVES

To identify the imaging features peculiar to congenital tracheal stenosis (CTS) complicated with left pulmonary artery sling (LPAS) with the aim of presenting a hypothesis of tracheal stenosis embryology in LPAS.

METHODS

We retrospectively reviewed CTS patients (with complete cartilaginous rings) admitted between April 2010 and July 2018. All the patients were classified into the LPAS or non-LPAS group, and their clinical characteristics and qualitative variables on computed tomography (CT) imaging were compared.

RESULTS

Of the 72 patients enrolled, 61 had bilateral lungs. Among the bilateral lung patients, 26 (43%) had LPAS. The tracheal bifurcation was significantly deeper, the stenotic region was longer, and the bronchial angle (especially in the right) was wider, in the LPAS group. The cut-off values for the thoracic vertebral level at the tracheal bifurcation (>4.8), subcarinal angle (>118.1), and right bronchial angle (>61.9) were useful for diagnosing suspected cases of LPAS. In the time-dependent course, LPAS complicated with a congenital heart defect was a statistically significant risk factor of respiratory symptoms (hazard ratio, 3.01; 95% confidence interval, 1.23-7.37; P = .02).

CONCLUSIONS

The CT findings described here should immediately raise suspicion of LPAS on chest X-ray and also suggest tracheal "squeezing and milking" by the surrounding vessels in the embryo. Patients with LPAS complicated with a heart defect should be followed carefully to determine the optimal timing of intervention.

Morphologic Analysis of Congenital Heart Disease With Anomalous Tracheobronchial Arborization

BACKGROUND

This study investigated the morphologic characteristics of congenital heart disease (CHD) combined with anomalous tracheobronchial arborization (ATBA) to provide new considerations for surgically treating congenital tracheal stenosis.

METHODS

A retrospective review of surgical experience with ATBA was conducted of 147 patients. The proportion of patients with ATBA combined with tracheal stenosis was determined. Four ATBA types were identified: type A, tracheal bronchus (n = 58); type B, bronchial trifurcation (n = 46); type C, bridging bronchus (n = 38); and type D, tracheal bronchus combined with bronchial trifurcation (n = 5). The rate of tracheoplasty for each type was determined. We measured the carina/pseudocarina angle and assessed the distribution of CHD, especially pulmonary artery sling.

RESULTS

The tracheal diameter of 14 patients (24.1%) with type A and 5 patients (10.9%) with type B was normal. There were 128 patients with tracheal stenosis and complete tracheal rings; of them, 113 patients received tracheoplasty. The tracheoplasty rate was higher for type C than type A (100% vs 62.1%, P < .001). The carina/pseudocarina angle was significantly reduced postoperatively (P < .001). The repair in 78 patients (60.9%) was combined with a pulmonary artery sling. A pulmonary azygos lobe was found in 10 patients (6.8%) and was resected.

CONCLUSIONS

ATBA is common in patients with congenital tracheal stenosis and may be associated with abnormal embryonic development. The new classification of ATBA has clinical significance in treating patients with congenital tracheal stenosis. The poor tracheal development cannot be explained merely with vascular compression. Tracheoplasty is currently the optimal option for every type.

Surgical indication for congenital tracheal stenosis complicated by pulmonary artery sling

Background

Congenital tracheal stenosis (CTS) is a rare and life-threatening disease in children. Although pulmonary artery sling (PA sling) complicated by CTS sometimes occurs, there are few reports detailing the management of CTS with PA sling. The purpose of this retrospective study was to determine the appropriate indications for surgical intervention for CTS complicated by PA sling.

Methods

We evaluated 42 patients (19 males and 23 females) with the median age of 9.9±3.3 months (range, 5-34 months) with CTS complicated by PA sling who were treated at our hospital between 2005 and 2018. Twenty-eight patients received both a slide tracheoplasty and PA re-implantation, and 14 patients were managed conservatively for CTS. Among the latter, nine patients received PA re-implantation only, and five were managed conservatively without any surgery. We determined the surgical indications by retrospectively comparing the DLR value [tracheal diameter (mm)/stenotic length ratio], history of ventilator respiration, mortality rate, and post-operative course of patients at a single institution.

Results

The cut-off value for the DLR was determined to be 5.9 (sensitivity: 0.929, specificity: 0.714) by using the ROC curve (AUC 0.89, P<0.05).

Conclusions

A DLR value under 5.9 may serve as a new surgical indication for CTS complicated by PA sling.

Surgical treatment of pulmonary artery sling and tracheal stenosis with or without tracheoplasty: A protocol for a systematic review and meta-analysis

BACKGROUND

Pulmonary artery sling (PAS) is rare, often with tracheal stenosis. And the postoperative mortality is high. For now, there is no consensus on the tracheoplasty for the patients with PAS and tracheal stenosis.

METHODS

Studies involving surgical repair of PAS and tracheal stenosis with and without tracheoplasty were identified by searching the PubMed, EMBASE, and the Cochrane Library databases until June 5, 2019. The assessed variables included ventilation time, early and late mortality, and symptom at follow-up. A random-effect/fixed-effect model was used to summarize the estimates of the mean difference (MD)/risk ratio (RR) with 95% confidence interval (CI).

RESULTS

This study will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will assess the safety and efficacy of tracheoplasty for patients with PAS and tracheal stenosis, and provide more evidence-based guidance in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42019139788.

Long-term outcomes of surgery for pulmonary artery sling in children

OBJECTIVES

Pulmonary artery (PA) sling is a rare vascular anomaly often associated with congenital tracheal stenosis. We describe the long-term outcomes with repair of this condition.

METHODS

A retrospective study was conducted at 2 institutions. From 1984 to 2018, 33 patients with PA sling underwent repair.

RESULTS

The median age at the time of surgery was 5.9 months (quartile 1-3: 2.5-12 months). Concomitant tracheal surgery was required in 21 patients (64%) where slide tracheoplasty was used in 11 patients (52%). There were no early deaths in patients who did not require tracheal surgery (n = 12). Operative mortality was 22% (2 of 9 patients) between 1984 and 1993, 11% (1 of 9 patients) between 1994 and 2003 and 6.7% (1 of 15 patients) between 2004 and 2018. The 15-year probability of survival for patients who had PA sling repair alone was 100%, and for patients who required PA sling and tracheal repair was 76 ± 10% (95% confidence interval 51-89%) (P = 0.08). The mean follow-up for survivors was 14 ± 9.8 years (3 months-33 years). All survivors were in the New York Heart Association functional class I/II at the last follow-up. Spirometry performed at a median age of 10.4 years after PA sling and tracheal surgery demonstrated obstructive lung defects with median forced expiratory volume in 1 s of 1.0 l (48% predicted), forced vital capacity of 1.5 l (74% predicted) and forced expiratory volume in 1 s/forced vital capacity of 0.69 (78% predicted).

CONCLUSIONS

Early mortality after PA sling repair is determined by the need for tracheal surgery. Though late survival was excellent, and the majority of survivors remained asymptomatic, long-term respiratory assessment and follow-up is warranted for these patients.

Three-dimensional printed degradable splint in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis

Pulmonary artery sling is a congenital cardiovascular disease and is usually accompanied by tracheobronchial stenosis. Generally, infants diagnosed with pulmonary artery sling should have surgery. However, the treatment of tracheobronchial stenosis is still controversial. Our team developed a customised, degradable, three-dimensional printed splint and successfully applied it in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis. We suggested that three-dimensional printing may be a novel and effective way to treat tracheobronchial stenosis and other diseases in children.

Bronchial Mismatch as a Predictor of Respiratory Failure After Congenital Tracheal Stenosis Repair

BACKGROUND

The purpose of this study was to identify predictors of postoperative respiratory failure after surgical tracheoplasty for congenital tracheal stenosis.

METHODS

Between February 2011 and April 2017, 16 infants underwent congenital tracheal stenosis repair. Preoperative computed tomography evaluation of the trachea and mainstem bronchi was performed. The primary outcome was midterm freedom from postoperative respiratory failure defined as persistent need for mechanical ventilation or surgical tracheobronchial reoperation. Bronchial mismatch, defined as [1 - (smaller bronchus diameter / larger bronchus diameter)] × 100, was analyzed in relation to the primary outcome.

RESULTS

Median age was 106 days (range, 1 to 406) and median weight was 5.3 kg (range, 2.6 to 8 kg). Four patients were neonates (25%) and 6 had genetic abnormalities (37.5%). There were no early nor late deaths. Median ventilation time was 5.5 days (range, 3 to 45). Mean follow-up time was 2.2 years (range, 0.1 to 4.5). Four patients with bronchial mismatch greater than 20% had postoperative respiratory failure (p = 0.002). Two of them underwent tracheostomy and were discharged with ventilation home care support. One underwent successful reoperation consisting of bilateral bronchial plasty with autologous cartilage rib grafts, and the other underwent successful right bronchial and tracheal reconstruction. One patient with bilateral bronchial hypoplasia underwent slide tracheoplasty associated with preemptive bilateral bronchial plasty and made a full recovery.

CONCLUSIONS

Surgical treatment of congenital tracheal stenosis in neonates and infants portends a good outcome. Bronchial mismatch greater than 20% can identify a subset of patients at increased risk for surgical reintervention and chronic respiratory failure. Slide tracheoplasty with preemptive bronchial reconstruction may prevent postoperative respiratory failure.

External stenting: A reliable technique to relieve airway obstruction in small children

OBJECTIVE

Airway obstruction in children may be caused by conditions such as vascular compression and congenital tracheobronchomalacia. Obstructive pulmonary vascular disease may be a detrimental sequel for patients with congenital heart disease. We evaluate our own original external stenting technique as a treatment option for these patients.

METHODS

Ninety-eight patients underwent external stenting (1997-2015). Cardiovascular anomalies were noted in 82 (83.7%). Nine patients had hypoplastic left heart syndrome and 6 had other types of single-ventricular hearts.

RESULTS

The median age at the first operation was 7.2 months (range, 1.0-77.1 months). The mechanisms were tracheobronchomalacia with (n = 46) or without (n = 52) vascular compression. Patients underwent 127 external stentings for 139 obstruction sites (62 trachea, 55 left bronchus, and 22 right bronchus). The stent sizes varied from 12 to 16 mm. There were 14 (8 in the hospital and 6 after discharge) mortality cases. Nine required reoperation for restenosis and 3 required stent removal for infection. The actuarial freedom from mortality and any kind of reoperation was 74.7% ± 4.6% after 2.8 years. The negative pressure threshold to induce airway collapse for congenital malacia (n = 58) improved from -15.9 to -116.0 cmH₂O. A follow-up computed tomography scan (>2.0 years interval from the operation; n = 23) showed the mean diameter of the stented segment at 88.5% ± 13.7% (bronchus) and 94.5% ± 8.2% (trachea) of the reference.

CONCLUSIONS

External stenting is a reliable method to relieve airway compression for small children, allowing an age-proportional growth of the airway.

Complicated Postoperative Course after Pulmonary Artery Sling Repair and Slide Tracheoplasty

Pulmonary artery sling (PAS) is a rare congenital condition in which the left pulmonary artery (LPA) arises from the right pulmonary artery, and then passes between the trachea and the esophagus to reach the left lung, thereby forming a sling around the airway. It is often associated with intrinsic tracheal stenosis due to complete cartilaginous rings. Therapeutic management nowadays consists of one-stage reimplantation of the LPA and tracheoplasty with cardiopulmonary bypass support. Here, we present a 7-week-old boy with PAS and long-segment tracheal stenosis (LSTS) who underwent surgical intervention consisting of reimplantation of the LPA and slide tracheoplasty. Multiple respiratory and cardiovascular complications marked the postoperative course. They consisted of recurrent failed attempts in weaning off mechanical ventilation due to bronchomalacia, left vocal cord paralysis, development of granulation tissue at the anastomosis and restenosis of the trachea, and the main stem bronchi requiring balloon dilatation. The patient also developed bilateral pulmonary artery thrombosis and stenosis of the LPA. After a prolonged hospitalization, the patient is doing well without any respiratory symptoms and has a good result on follow-up bronchoscopy 1 year after the initial surgery. The stenosis of the LPA responded well to percutaneous balloon dilatation 12 months after the primary surgery. The case illustrates that even though surgical techniques are improving and are in general associated with a low morbidity and mortality, management of PAS and tracheal stenosis can still be challenging. However, good long-term outcome can be achieved if the initial postoperative phase is overcome.

Double trouble: fetal diagnosis of a pulmonary artery sling and vascular ring

Left pulmonary artery slings and vascular rings are rare congenital anomalies definable by fetal echocardiography. Left pulmonary artery slings are associated with high respiratory morbidity and mortality. Prenatal diagnosis of a left pulmonary artery sling should prompt delivery planning for postnatal management at a pediatric tertiary care center.

Vascular rings

The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time.

Abnormal cardiac axis as a prenatal marker of left pulmonary artery sling

Left pulmonary artery sling (LPAS) is a rare vascular anomaly. The left pulmonary artery arises distally from the right pulmonary artery on the right side of the trachea and passes between the trachea and esophagus towards the left lung, compressing the lower trachea. LPAS is associated with congenital tracheal stenosis, which frequently requires early surgical intervention and has a poor prognosis due to severe airway obstruction after birth. Therefore, LPAS should be prenatally diagnosed to prepare for surgical intervention for tracheal stenosis. To the best of our knowledge, there are few reports on prenatal echocardiographic findings in LPAS. We report three prenatal cases of LPAS, which resulted in respiratory symptoms. We discuss fetal ultrasound findings and highlight the abnormal rotation of the fetal cardiac axis to the right as a useful sign in the prenatal screening of LPAS.

Rare Upper Airway Anomalies

A broad spectrum of congenital upper airway anomalies can occur as a result of errors during embryologic development. In this review, we will describe the clinical presentation, diagnosis, and management strategies for a few select, rare congenital malformations of this system. The diagnostic tools used in workup of these disorders range from prenatal tests to radiological imaging, swallowing evaluations, indirect or direct laryngoscopy, and rigid bronchoscopy. While these congenital defects can occur in isolation, they are often associated with disorders of other organ systems or may present as part of a syndrome. Therefore workup and treatment planning for patients with these disorders often involves a team of multiple specialists, including paediatricians, otolaryngologists, pulmonologists, speech pathologists, gastroenterologists, and geneticists.

Congenital vascular rings: a clinical challenge for the pediatrician

Vascular rings are congenital anomalies that lead to variable degrees of respiratory problems or feeding difficulties by forming a complete or partial ring compressing the trachea, the bronchi, and the esophagus. The clinical diagnosis of vascular rings is often challenging for the pediatrician because the clinical manifestations are heterogeneous and nonspecific. Symptoms can vary from wheezing, stridor, dyspnea, and/or dysphagia to life-threatening conditions; however, they may not be present. The aim of this study is to review the recent literature on this subject and describe new developments in diagnostics and imaging.

Computed tomography in the evaluation of vascular rings and slings

Vascular rings are congenital abnormalities of the aortic arch-derived vascular and ligamentous structures, which encircle the trachea and oesophagus to varying degrees, resulting in respiratory or feeding difficulties in children. A sling is an abnormality of the pulmonary arterial system resulting in airway compression. Although several imaging examinations are available for the evaluation of these anomalies, computed tomography (CT) has become the preferred test because of rapid acquisitions, making it feasible to perform the study without sedation or general anaesthesia. Furthermore, CT provides excellent spatial and temporal resolution, a wide field of view, multiplanar reconstruction capabilities and simultaneous evaluation of the airway. In this review, the current role and technique of CT in the evaluation of vascular rings are discussed. A brief discussion of the embryology of the aorta and branch vessels is followed by discussion and illustration of common and some uncommon vascular rings along with critical information required by surgeons. Teaching Points • Computed tomography is valuable in the evaluation of vascular rings.• Due to variable clinical and imaging presentations, diagnosis of vascular rings is often challenging.• Laterality of the arch is critical in surgical management.

Pulmonary artery sling with tracheal stenosis

Pulmonary artery sling (PAS) is a rare congenital heart disease in which the left pulmonary artery (LPA) originates from the right pulmonary artery (RPA) and encircles the distal trachea and right mainstem bronchus as it courses between the trachea and esophagus. Typically, patients with PAS have some respiratory symptoms, either due to external tracheal compression that can be corrected by relief of the sling mechanism, or due to severe diffuse tracheal stenosis with complete rings (ring-sling complex). The diagnosis of PAS is optimally made by echocardiography, while bronchoscopy is the key to the assessment of tracheal stenosis. Diagnosis is indication for surgery. Repair using a strategy of median sternotomy, cardiopulmonary bypass, division of the LPA and reimplantation into the main pulmonary artery (MPA), and simultaneous tracheal repair takes preference. Tracheal repair should be considered only in clinically symptomatic patients. The techniques of free tracheal autograft plasty or slide tracheoplasty offer promising results, and the choice of tracheal reconstruction should be guided by the clinical experience of the surgeon. Coexisting intracardiac pathologies are repaired at the same time. Postoperative care requires close multidisciplinary effort to achieve the best long-term result.

Surgical management of pulmonary artery sling in children

OBJECTIVES

Pulmonary artery (PA) sling is a rare vascular anomaly associated with congenital tracheal stenosis. The natural history is poor and these patients often require early surgical intervention. We describe our experience with repair of this condition.

METHODS

From 1984 to 2011, 21 patients with PA sling underwent repair at the Royal Children's Hospital (median age, 5.9 months). PA sling was associated with compression of the trachea in all patients. Tracheal surgery was required in 12 (57.1%) patients. All patients had an echocardiogram, and concomitant repair of coexisting cardiac anomalies was performed in 6 (28.6%, 6/21) patients.

RESULTS

Operative mortality was 14.3% (3/21), occurring at 19 days, 4.4 months, and 5 months after surgery. Operative mortality for the first 10 years was 22.2% (1984-1993; 2/9), the next 10 years was 14.3% (1994-2003; 1/7), and 0% for the most recent 7 years (2004-2011; 0/5). All deaths occurred in patients requiring tracheal repair (25%, 3/12). No deaths have occurred since 2004 with introduction of the slide tracheoplasty technique. One (5.6%, 1/18) late death occurred at 8 months after repair. After tracheal repair, intervention for excessive granulations and tracheomalacia was necessary in 6 (50%, 6/12) patients. Median follow-up was 8 years (mean, 8.6 ± 6.4 years; range, 5 months to 20.6 years), and all survivors (100%, 17/17) remain asymptomatic.

CONCLUSIONS

Children with PA sling who do not require tracheal surgery have excellent outcomes. Mortality is determined by the need for tracheal surgery. However, with the advent of the slide tracheoplasty technique, mortality can be reduced. Survival beyond 1 year after surgery offers excellent prognosis.

The triad of bridging bronchus malformation associated with left pulmonary artery sling and narrowing of the airway: the legacy of Wells and Landing

Although noted in the 19th century, it was not until 1938 that Scheid published the combination of left pulmonary artery sling and narrowing of the airway due to annular tracheal cartilages. Unaware of these prior descriptions, and without a precise preoperative diagnosis, Willis Potts in Chicago performed the first successful sling repair in 1953. In 1976, Cohen and Landing described Scheid's combination of left pulmonary artery sling and stenosis caused by complete tracheal rings, and the term "ring-sling complex" was introduced by Berdon in 1984. Four years later, Wells and Landing noted characteristic tracheobronchial malformations associated with these lesions and proposed a classification that has been confirmed to be clinically relevant in recent cross-sectional imaging studies.

Left pulmonary artery sling with right lung aplasia

We report 2 cases of right pulmonary aplasia with left pulmonary artery sling responsible for severe respiratory symptoms. Repositioning of the left pulmonary artery without tracheal surgery was successful in both patients. The postoperative course was simple, and the outcome was favorable at last follow-up (after 2 years and 3 months, respectively). Computed tomography provided an accurate diagnostic evaluation that helped to choose the best surgical technique.

A History of Pediatric Tracheal Surgery

Tracheal stenosis in children is primarily caused by congenital complete cartilage tracheal rings. These infants present with severe respiratory distress early in life. The purpose of this review is to examine the history of surgical intervention for infants and children with congenital tracheal stenosis. Most of the significant advances in the surgical treatment of patients with congenital tracheal stenosis have occurred over the past 50 years. The highlights of the historical events include the first pulmonary artery sling repair (1953), tracheal resection (1958), cartilage tracheoplasty (1981), pericardial tracheoplasty (1982), slide tracheoplasty (1989), homograft tracheoplasty (1994), and tracheal autograft (1996). The results of surgical intervention on patients with congenital tracheal stenosis have steadily improved, particularly during the past 20 years. Most successful centers are using cardiopulmonary bypass, simultaneous repair of associated pulmonary artery sling and cardiac anomalies, and the current procedure of choice—slide tracheoplasty. During the past 50 years, significant advances have been made in the care of infants with congenital tracheal stenosis. The outlook for these children is currently quite good, and successful outcomes are particularly evident at institutions with a careful multidisciplinary approach to these patients.