Left Pulmonary Artery Sling Research Articles

Evolution of Surgical Approaches in the Management of Congenital Tracheal Stenosis: Single-Center Experience.

Congenital tracheal stenosis (CTS) is a serious and rare condition that often presents a complex surgical challenge. We reviewed the evolution of surgical approaches to the management of CTS at a single institution. We conducted a retrospective clinical review of all patients who underwent surgical repair of CTS at our institution. From January 1992 to January 2014, a total of 30 patients (median age 92 days; range 3 days-1.7 years) underwent surgery for CTS at our institution. Techniques included slide tracheoplasty (n = 16), tracheal resection (n = 10), pericardial patch tracheoplasty (n = 3), and costal cartilage tracheoplasty (n = 1). Twenty-two (73%) patients had associated intracardiac or great vessel anomalies, including 18 (60%) with left pulmonary artery sling. Five (17%) patients had associated single lung malformation. All procedures were performed via a median sternotomy with cardiopulmonary bypass. Median postoperative length of stay was 25 days (range, 5-431 days). Late airway reintervention was required in seven (26%), including two (15%) infants after slide tracheoplasty, two (22%) posttracheal resection, and two (100%) post pericardial patch tracheoplasty. The one patient who underwent costal cartilage tracheoplasty required multiple reinterventions. Overall mortality was 13% (n = 4), two deaths occurred post slide tracheoplasty, one death occurred after tracheal resection, and one after pericardial patch tracheoplasty, respectively. Slide tracheoplasty is the procedure of choice for repair of CTS, while tracheal resection is a viable option for patients with discreet, short-segment stenosis.

SIMULATION ANALYSIS OF DEFORMATION AND STRESS OF TRACHEAL AND MAIN BROCHIAL WALL FOR SUBJECTS WITH LEFT PULMONARY ARTERY SLING

Left pulmonary artery sling (LPAS) is a kind of severe congenital anomaly, where the stenoses usually occur at trachea and main bronchi for the external compression of the artery sling. Computed tomography (CT) images can provide accurate morphological analysis, but the airflow and its effects on the airway wall are unknown and seldom investigated. In the present study, a uni-directional coupling fluid–structure interaction (UCFSI) method is employed to simulate the deformation and stress of tracheal and main bronchial wall for four LPAS subjects and one health control. Much higher airflow velocity is observed for LPAS subjects due to the stenosis, and the deformation and equivalent stress of airway wall are about 50–900 and 90–1000 times of the health control, respectively. The direction of tracheal shift may be related to the airway shape, and is opposite to the net reaction force. The influences of inlet flow velocity and wall thickness on the deformation and stress are significant and their relationship is non-linear. These results suggest that the UCFSI simulation is helpful for the quantitative analysis on the deformation and stress of the airway wall and better understanding of LPAS mechanism.

P09.01: Prenatal cases of left pulmonary artery sling: a report of three cases

<scp>P</scp>09.01: Prenatal cases of left pulmonary artery sling: a report of three cases

右肺低形成・left pulmonary artery sling・bridging bronchus を合併した先天性気管狭窄症に対してスライド気管形成術を施行した1 例

右肺低形成・left pulmonary artery sling・bridging bronchus を合併した先天性気管狭窄症に対してスライド気管形成術を施行した1 例

Treatment strategies in the management of severe complications following slide tracheoplasty in children

This study focuses on the different surgical and endoscopical treatment alternatives when dealing with severe complications after slide tracheoplasty (STP). Retrospective study of patients with symptomatic congenital tracheal stenosis (CTS) admitted to a single institution, between January 1997 and January 2013, surgically treated by means of STP. The following variables were evaluated: demographics, preoperative tracheal stenosis characteristics, associated anomalies and outcome measures. Cohort included 14 patients (8 males and 6 females) with a mean age of 8.7 months when treated (range, 1-43 m). Eleven patients (78%) showed a long segment CTS (>30% of total tracheal length) and 9 (64%) had associated cardiac or great vessel anomalies (left pulmonary artery sling). Three patients (21%) showed severe postoperative complications that required significant airway reintervention: tracheal resection of a restenotic segment, laser division with balloon dilatation of a residual stenosis and placement of a biodegradable endotracheal stent in an extensive tracheal narrowing. All patients are in good clinical condition with a mean follow-up of 6.3 years (range, 2 months to 16 years). STP has become the procedure of choice when dealing with CTS. Although it shows clear advantages compared with other surgical techniques, severe and difficult to manage complications may occur. Surgeons involved in their treatment should be familiar with diverse surgical and endoscopical procedures. Biodegradable airway stenting is a new and promising technique when long and severe post-surgical tracheal stenosis is present.

Computational fluid dynamics simulation of airflow in the trachea and main bronchi for the subjects with left pulmonary artery sling.

BackgroundLeft pulmonary artery sling (LPAS) is a rare but severe congenital anomaly, in which the stenoses are formed in the trachea and/or main bronchi. Multi-detector computed tomography (MDCT) provides useful anatomical images, but does not offer functional information. The objective of the present study is to quantitatively analyze the airflow in the trachea and main bronchi of LPAS subjects through computational fluid dynamics (CFD) simulation.MethodsFive subjects (four LPAS patients, one normal control) aging 6-19 months are analyzed. The geometric model of the trachea and the two main bronchi is extracted from the MDCT images. The inlet velocity is determined based on the body weight and the inlet area. Both the geometric model and personalized inflow conditions are imported into CFD software, ANSYS. The pressure drop, mass flow ratio through two bronchi, wall pressure, flow velocity and wall shear stress (WSS) are obtained, and compared to the normal control.ResultsDue to the tracheal and/or bronchial stenosis, the pressure drop for the LPAS patients ranges 78.9 - 914.5 Pa, much higher than for the normal control (0.7 Pa). The mass flow ratio through the two bronchi does not correlate with the sectional area ratio if the anomalous left pulmonary artery compresses the trachea or bronchi. It is suggested that the C-shaped trachea plays an important role on facilitating the air flow into the left bronchus with the inertia force. For LPAS subjects, the distributions of velocities, wall pressure and WSS are less regular than for the normal control. At the stenotic site, high velocity, low wall pressure and high WSS are observed.ConclusionsUsing geometric models extracted from CT images and the patient-specified inlet boundary conditions, CFD simulation can provide vital quantitative flow information for LPAS. Due to the stenosis, high pressure drops, inconsistent distributions of velocities, wall pressure and WSS are observed. The C-shaped trachea may facilitate a larger flow of air into the left bronchus under the inertial force, and decrease the ventilation of the right lung. Quantitative and personalized information may help understand the mechanism of LPAS and the correlations between stenosis and dyspnea, and facilitate the structural and functional assessment of LPAS.

Single Stage Repair of Tetralogy of Fallot Associated With Left Pulmonary Artery Sling and Tracheal Stenosis

We report a rare case of tetralogy of Fallot (TOF) with left pulmonary artery (LPA) sling with tracheal stenosis. The patient underwent successful surgery in one stage involving intracardiac repair of TOF, LPA reimplantation and resection of tracheal stenosis with end-to-end anastomosis.

Left pulmonary artery sling: Difference in monochorionic monoamniotic twin presentation

Pulmonary artery sling (PAS) is a rare congenital vascular anomaly where the left pulmonary artery (LPA) originates from the right pulmonary artery and passes between the trachea and esophagus. Limited literature has been published about PAS in twins. This report demonstrates two different outcomes in mono-mono twins presenting with PAS. Patients with PAS can experience sequelae including wheezing, stridor, atelectasis, or emphysema. Vascular rings occur when the anomalous LPA encircles the airway and esophagus, causing direct compression and respiratory distress. In the case of LPA sling, the sling does not encircle the airway and esophagus but acts as a cradle so the airway which is adjacent to the vessel is not directly compressed. Unfortunately, patients with LPA sling may become severely ill due to airway narrowing even when there is no compression of the adjacent airway. This is the more common presentation in PAS and was seen in Twin A whereas direct airway compression was seen in Twin B. PAS usually presents in patients during their first year of life and high clinical suspicion is important for diagnosis. As this case report demonstrates, presentations and outcomes can be variable in mono-mono twins with LPS and as a result, appropriate investigations should be offered with monitoring of respiratory compromise.

Univentricular Heart With Bridging Bronchus and Sling Left Pulmonary Artery

A bridging bronchus (BB) is a rare congenital heart anomaly. Frequently, BB also is complicated with congenital cardiac malformation, especially with sling (retrotracheal) left pulmonary artery (SLPA). This report presents a patient who underwent a Norwood procedure for a complex congenital heart disease with BB and SLPA.

A case of dyspnoea evaluated by cardiac computed tomography angiography

A 1-year-old boy presented with failure to thrive and dyspnoea of 4 months duration. He was evaluated and found to be malnourished. His clinical examination revealed a pansystolic murmur at the left parasternal border with no jugular venous pressure (JVP) elevation or other features of heart failure. Two-dimensional echo revealed a small ventricular septal defect (VSD) with left-to-right shunt and absent left pulmonary artery (LPA). The cardiac computed tomography angiography imaging study showed all the characteristic features of an LPA sling with tracheal compression: A. Normal size of main pulmonary artery (MPA), right pulmonary artery (RPA) and LPA. B. Small perimembranous VSD. C. There is anomalous origin of LPA just above tracheal bifurcation with a course posterior to the trachea and supplying the left lung (Figures 1–5). Figure 1 Origin of the left pulmonary artery (LPA) from right pulmonary artery (RPA). Figure 2 Complete course of the left pulmonary artery (LPA). Figure 3 Computed tomography angiography axial image showing the origin and posterior course of the left pulmonary artery (LPA). Figure 4 Volume rendering technique image showing posterior view of the pulmonary arteries and the aorta. LPA: left pulmonary artery. Figure 5 Volume rendering technique showing the MPA, RPA, and LPA origin. LPA: left pulmonary artery, MPA: main pulmonary artery, RPA: right pulmonary artery. D. There is mild tracheal compression between RPA anteriorly and LPA posteriorly. Child underwent VSD closure and reimplantation of LPA to MPA anterior to trachea. Diffuse narrowing in proximal LPA improved as flow improved in LPA. There was gradual resolution of the dyspnoea.

A New Morphologic Classification of Congenital Tracheobronchial Stenosis

Congenital tracheal stenoses are rare and life-threatening anomalies, associated with considerable variation in both morphology and prognosis. They have been classified previously according to the length of the stenosis or the severity of the symptoms, but not according to bronchial involvement. Data from patients who underwent slide tracheoplasty for long-segment (>50%) congenital tracheal stenosis were collected. We identified four different types of bronchial arborization (normal, n=52; tracheal right upper lobe bronchus, n=10; carina with "trifurcation," n=14; and unilateral bronchial and lung agenesis, n=8). Each type included congenital tracheal (above the carina) or tracheobronchial (extending below the carina) stenosis. Eighty-four children were enrolled in the study. Preoperative ventilation was necessary in 44 patients (52.4%; 75% in patients with a single lung), and preoperative extracorporeal membrane oxygenation was needed in 10 patients (11.9%). Preoperative tracheostomy was present in 3 patients initially treated elsewhere (3.5%), and a left pulmonary artery sling was performed in 44% (37 of 84). The overall mortality was 13% (11 of 84), 7.9% in patients with tracheal stenosis and 28.6% with tracheobronchial stenosis. No deaths occurred in patients with right upper lobe bronchus anatomy. Endoscopic procedures after slide tracheoplasty were required in 34 patients (40.4%). Stents were placed in 18 patients (21.4%), with a higher incidence in those with bronchial trifurcation (42.8%, 6 of 12). This classification appears useful for the morphologic characterization of congenital airway stenosis and could be the benchmark for future prospective studies on the outcome of these patients.

Multislice spiral CT of left pulmonary artery sling with tracheobronchial anomaly

Objective To discuss the value of MSCT in diagnosis of left pulmonary artery sling (LPAS) with tracheobronchial anomaly.Methods MSCT was performed in 9 children with LPAS and tracheobronchial anomalies,CT findings were analyzed retrospectively. Results According to the Wells classification of LPAS,which includes two main types and two subtypes,there were 2 patients of type 1A,3 patients of type 1 B,2 patients of type 2A and 2 patients of type 2B.All of children had tracheobronchial stenosis.Local tracheobronchial stenosis was found in 4 patients ( all were type 1 ) and long tracheobronchial stenosis in 5 patients ( 1 patient with type 1 and 4 patients with type 2).Conclusions MSCT is an ideal imaging modality for simultaneously identifying LPAS and associated tracheobronchial anomalies.The Wells classification is very useful for operation planning. Key words: Pulmonary artery; Cardiovascular abnormalities; Tracheal stenosis ; Tomography,X-ray computed

Congenital rubella syndrome and left pulmonary artery sling

To the Editors: The classic rubella syndrome is characterised by the combination of cardiac, ocular and hearing defects, although infection and damage can occur in every organ system. Since the advent of effective vaccination, the number of new cases of congenital rubella has plummeted. The cardiac abnormality most frequently found in rubella syndrome is a combination of branch pulmonary artery stenosis and patent ductus arteriosus, though isolated branch pulmonary artery stenosis is twice as common as isolated patent ductus arteriosus [1]. However, a wide variety of cardiac malformations may be produced, such as ventricular and atrial septal defects, stenosis of the pulmonary and aortic valves, Fallot's tetralogy, coarctation of the aorta, tricuspid atresia and transposition of the great vessels. Localised pulmonary arterial stenosis may appear in one of three main forms. First, there may be …

Left Pulmonary Artery Sling Associated with Patent Ductus Arteriosus and Atrial Septal Defect: Evaluation with Multidetector CT

We report a case of left pulmonary artery sling associated with patent ductus arteriosus and atrial septal defect in a 21-month-old child. 256-slice MDCT provides valuable information, such as abnormal origin of the left pulmonary artery, the relationship between pulmonary artery and airway, the diameter of the patent ductus artery and atrial septal defect. The information is helpful in diagnosis, pre-operative evaluation and post-operative follow-up of LPS.

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.

Horseshoe lung associated with left lung hypoplasia and single left pulmonary vein; a rare combination

Horseshoe lung (HL) is a rare bronchovascular anomaly in which the posterobasal segments of the right and left lung are fused with a narrow isthmus of pulmonary parenchyma in a common pleural space behind the heart and anterior to the aorta and oesophagus. HL is mostly associated with unilateral lung hypoplasia (most frequently the right lung) in conjunction with the Scimitar syndrome and is also associated with cardiovascular anomalies, such as atrial septal defects, ventricular septal defects, tetralogy of Fallot, and hypoplastic left ventricule. 1 Oguz B. Alan S. Ozcelik U. et al. Horseshoe lung associated with left-lung hypoplasia, left pulmonary artery sling and bilateral agenesis of upper lobe bronchi. Pediatr Radiol. 2009; 39: 1002-1005 Crossref PubMed Scopus (15) Google Scholar , 2 Salerno T. Guccione P. Malena S. et al. Horseshoe lung associated with unique left pulmonary vein: an unreported association. Pediatr Cardiol. 2010; 31: 905-907 Crossref PubMed Scopus (8) Google Scholar , 3 Jeewa A. Culham J.A.G. Human D.G. A case of horseshoe lung and complex congenital heart disease in a term newborn. Pediatr Radiol. 2010; 40: 206-209 Crossref PubMed Scopus (5) Google Scholar HL with left lung hypoplasia is extremely rare, with only a few cases reported in the literature. 1 Oguz B. Alan S. Ozcelik U. et al. Horseshoe lung associated with left-lung hypoplasia, left pulmonary artery sling and bilateral agenesis of upper lobe bronchi. Pediatr Radiol. 2009; 39: 1002-1005 Crossref PubMed Scopus (15) Google Scholar , 2 Salerno T. Guccione P. Malena S. et al. Horseshoe lung associated with unique left pulmonary vein: an unreported association. Pediatr Cardiol. 2010; 31: 905-907 Crossref PubMed Scopus (8) Google Scholar , 3 Jeewa A. Culham J.A.G. Human D.G. A case of horseshoe lung and complex congenital heart disease in a term newborn. Pediatr Radiol. 2010; 40: 206-209 Crossref PubMed Scopus (5) Google Scholar , 4 Ersoz A. Soncul H. Gokgoz L. et al. Horseshoe lung with left lung hypoplasia. Thorax. 1992; 47: 205-206 Crossref PubMed Scopus (23) Google Scholar To the authors’ knowledge, this is the first case of HL associated with left lung hypoplasia and a single left pulmonary vein as depicted using multidetector computed tomography (MDCT) in the literature. These complex bronchovascular anomalies require angiography, bronchoscopy, echocardiography, and also CT for correct diagnosis. With development of MDCT, a non-invasive imaging technique, it is possible to visualize vascular, bronchial, and parenchymal structures during a single imaging session via multiplanar two (2D) and three-dimensional (3D) images. 1 Oguz B. Alan S. Ozcelik U. et al. Horseshoe lung associated with left-lung hypoplasia, left pulmonary artery sling and bilateral agenesis of upper lobe bronchi. Pediatr Radiol. 2009; 39: 1002-1005 Crossref PubMed Scopus (15) Google Scholar , 5 Akay H.O. Kervancıoglu M. Nazaroglu H. et al. Horseshoe lung associated with rare bilateral variant of scimitar syndrome: demonstration by 64-slice MDCT angiography. Pediatr Radiol. 2008; 38: 563-566 Crossref PubMed Scopus (12) Google Scholar

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.

Surgical outcome of slide tracheoplasty in patients with long congenital segment tracheal stenosis and single lung

The aim of the study is to assess the surgical outcome of slide tracheoplasty in patients with congenital tracheal stenosis and single lung. Pre, intra- and postoperative data were collected. Anatomy and associated anomalies were described. Seven patients (median age 5 months; range 39 days-1 year) with single lung underwent slide tracheoplasty. Single right lung was present in four patients. Associated anomalies were present in four patients (56%) including vascular ring, left pulmonary artery (LPA) sling, VACTERL (abnormalities of the vertebrae, anus, cardiovascular tree, trachea, oesophagus, renal system, and limb buds) syndrome, atrial septal defect (ASD) and aberrant left subclavian artery. Six patients (85%) needed preoperative ventilation and two (28%) needed preoperative extracorporeal membrane oxygenation (ECMO). Median postoperative ventilation was 7 days (6-35 days). Two patients needed postoperative ECMO, one of whom required preoperative ECMO. Complications occurred in five patients (71%): reintubation due to pneumothorax, pneumonia and several tracheal dilatations due to recurrent tracheal stenosis, which was eventually stented. There was one hospital death in a patient, who could not be weaned off ECMO due to severe distal malacia. At a median follow-up of 16 months (7 days-7 years), all survivors are in good clinical condition and without additional stenting. Slide tracheoplasty can be performed in patients with single lung and tracheal stenosis with a good surgical outcome.

Prenatal diagnosis of fetal left pulmonary artery sling

Left pulmonary artery (LPA) sling is a very rare anomaly in which the LPA arises distally, far from the right pulmonary artery on the right side of the distal trachea, turns sharply leftwards around the trachea and courses to the left lung hilum through the space between the trachea and esophagus. LPA sling is often associated with distal tracheal narrowing, due to either intrinsic stenosis or secondary compression by the anomaly itself. To our knowledge, prenatal diagnosis of LPA sling has not been reported so far. We report a case in which LPA sling was diagnosed during fetal ultrasound examination.

Repair of Complex Tracheobronchial Stenosis With Left Pulmonary Artery Sling and Bridging Bronchus

Slide tracheoplasty with reimplantation of the left pulmonary artery is one of the preferred techniques for repair of long-segment congenital tracheal stenosis in association with a pulmonary artery sling. Left pulmonary artery sling associated with a right upper bronchus from the trachea (tracheal bronchus) and stenosis of the bridging bronchus is a more complicated situation. We present an infant with left pulmonary artery sling, and stenosis of the bridging bronchus, carina, and both right and left main bronchi. His condition was successfully repaired using the combination of slide tracheoplasty and tracheal autograft techniques.