Esophageal atresia and tracheal stenosis: use of three-dimensional CT and virtual bronchoscopy in neonates, infants, and children

Recurrent tracheo-esophageal fistula- management challenges: Case report and review of current literature

Recurrent tracheoesophageal fistula is a rare complication of esophageal atresia surgery with an incidence of 3-15%. The presentation is subtle and is often missed, presenting as choking episodes during feed and recurrent chest infections. It is both a diagnostic and management challenge and requires a dedicated multidisciplinary pediatric surgical setup with adequate infrastructure for optimal management. We present a case of recurrent tracheoesophageal fistula which was diagnosed at our center. The patient underwent successful surgical management and is thriving well at six months follow-up period.

Clinical features of a tracheoesophageal fistula associated with complete tracheal rings

PURPOSE

A tracheoesophageal fistula (TEF) associated with complete tracheal rings (CTR) is extremely rare. This study aimed to elucidate the clinical features of this combination.

METHODS

Records of 39 patients diagnosed with TEF with or without CTR between January 2013 and February 2023 were retrospectively reviewed. Data collected included location of the TEF and CTR, esophageal gap, surgery of TEF/esophageal atresia (EA), and symptoms of CTR.

RESULTS

Seven patients had CTR, while 32 patients did not have CTR. TEF was frequently located higher than the T4 vertebra, and the median esophageal gap was shorter in patients with CTR than in those without (5/7 [71.4%] vs. 6/32 [18.8%], P = 0.012; 0 (range: 0-15) mm vs. 13.3 (range: 0-40) mm, P = 0.017, respectively). TEF was located just above the beginning of the CTR in all patients. All patients with CTR underwent primary esophageal anastomosis. Additionally, two patients were diagnosed with CTR before TEF/EA repair. A tracheal tube was prevented from contacting the CTR during TEF/EA repair, and respiratory insufficiency did not occur.

CONCLUSIONS

Our results may help pediatric surgeons in the management of TEF with CTR.

Magnetic Resonance Imaging-Based Evaluation of Anatomy and Outcome Prediction in Infants with Esophageal Atresia

INTRODUCTION

There is currently no validated diagnostic modality to characterize the anatomy and predict outcomes of tracheal esophageal defects, such as esophageal atresia (EA) and tracheal esophageal fistulas (TEFs). We hypothesized that ultra-short echo-time MRI would provide enhanced anatomic information allowing for evaluation of specific EA/TEF anatomy and identification of risk factors that predict outcome in infants with EA/TEF.

METHODS

In this observational study, 11 infants had pre-repair ultra-short echo-time MRI of the chest completed. Esophageal size was measured at the widest point distal to the epiglottis and proximal to the carina. Angle of tracheal deviation was measured by identifying the initial point of deviation and the farthest lateral point proximal to the carina.

RESULTS

Infants without a proximal TEF had a larger proximal esophageal diameter (13.5 ± 5.1 mm vs. 6.8 ± 2.1 mm, p = 0.07) when compared to infants with a proximal TEF. The angle of tracheal deviation in infants without a proximal TEF was larger than infants with a proximal TEF (16.1 ± 6.1° vs. 8.2 ± 5.4°, p = 0.09) and controls (16.1 ± 6.1° vs. 8.0 ± 3.1°, p = 0.005). An increase in the angle of tracheal deviation was positively correlated with duration of post-operative mechanical ventilation (Pearson r = 0.83, p < 0.002) and total duration of post-operative respiratory support (Pearson r = 0.80, p = 0.004).

DISCUSSION

These results demonstrate that infants without a proximal TEF have a larger proximal esophagus and a greater angle of tracheal deviation which is directly correlated with the need for longer post-operative respiratory support. Additionally, these results demonstrate that MRI is a useful tool to assess the anatomy of EA/TEF.

Flexible Bronchoscopy Diagnosis of Uncommon Congenital H-type Tracheoesophageal Fistula, Dual Fistulae, Bronchoesophageal Fistula, and Recurrence of Fistula in Children: A 20-year Experience

BACKGROUND

Interventional pediatric flexible bronchoscopy has many advantages over radiologic investigations in diagnosing uncommon congenital H-type tracheoesophageal fistula (TEF), dual TEF, bronchoesophageal fistula (BEF) and fistula recurrence including higher rates of identification and anatomic localization with guide wire cannulation. We compare the diagnostic utility of flexible bronchoscopy to radiologic techniques for congenital aerodigestive fistula.

METHODS

A single center retrospective review was completed of all cases of pediatric TEF and BEF diagnosed with flexible bronchoscopy between January 2000 and November 2020.

RESULTS

Fistulae were diagnosed 21 times in 18 patients at a median age of 1.22 years (interquartile range: 0.50 to 2.99). The median time from diagnosis to repair was 17.5 days (interquartile range: 5.5 to 43). Symptoms commonly related to fistula were found in all patients. Uncommon fistulae included single H-type TEF (n=10, 47.6%), dual H-type TEF (n=2, 9.5%), dual proximal and distal TEF with esophageal atresia (n=5, 23.8%), TEF recurrence (n=2, 14.3%), BEF (n=1, 4.8%), and a BEF recurrence (n=1, 4.8%). Flexible bronchoscopy confirmed the diagnosis in all fistulae using a guide wire cannulation or methylene blue dye injection. A combined procedure with simultaneous bronchoscopy and esophagoscopy was used for 6 fistulae. The positive examination rate was 75% for bronchoscopy compared with 2.6% for contrast swallow studies and 28.6% for tube esophagograms.

CONCLUSIONS

Flexible bronchoscopy should be considered as a first line investigation in uncommon aerodigestive fistulae. In the absence of a skilled bronchoscopist, the best radiologic investigation is a pull-back tube esophagogram but may still require endoscopic confirmation at the time of fistula repair.

The utility of CT virtual bronchoscopy in the esophageal lung diagnosis: A case report

The esophageal lung is a variant of the communicating bronchopulmonary foregut malformation (CBPFM). It needs a high index of suspicion for diagnosis because it is a rare condition and does not have specific symptoms. A CT scan or an esophageal contrast study, showing direct communication between the airways and the esophagus or stomach, confirms the diagnosis. Patients with esophageal lung need flexible bronchoscopy for evaluating tracheobronchial anomalies.

We present a three-month-old boy with a right esophageal lung in which the CT virtual bronchoscopy showed an absence of the right main bronchus at the carina level. This case report highlights the importance of CT virtual bronchoscopy as an alternative to flexible bronchoscopy for the diagnosis of tracheobronchial anomalies associated with CBPFM.

Determining normal values for lower trachea and bronchi size in children by computed tomography (CT)

BACKGROUND

Normative data for central airway dimensions are a prerequisite to objectively assess large airway pathologies. Studies with computed tomography (CT) measurements of normal trachea and bronchi size in children are scarce.

OBJECTIVE

The purpose of this study is to establish normal values of central airway dimensions in children by CT.

METHODS

The study included chest CT studies from children aged 0-18 years. Any condition that predisposed the patient to have an abnormal tracheal or bronchial size was excluded. Airway diameters and cross-sectional area (CSA) were measured using double oblique reconstructions at five levels: proximal trachea, mid-trachea, distal trachea, right main bronchus, and left main bronchus.

RESULTS

The inclusion criteria were met by 110 subjects (mean age, 10.8 years; SD, 5.2 years). Various regression models that considered the relationship between patient demographics and anteroposterior (AP) diameter, transverse diameter, and CSA at each of the five levels were assessed. R² was utilized to select the best model. Multiple formulae (using patient age) were developed to calculate expected normal dimensions for five levels in the central airways on the natural log scale. Finally, z-scores were obtained for central airway dimensions at these five levels.

CONCLUSION

Normative data in pediatric central airways are crucial to identify large airway pathologies. We propose using the formulae devised in our study to calculate the predicted dimensions of central airways and their z-scores in pediatric patients. Normative data from our study will aid in objective quantification of central airways, increase clinician confidence, and provide appropriate patient care.

Changes of intrathoracic trachea with respiration in children: A metrical assessment based on 3D CT models

AIM

To assess the tracheal volume and the effect of respiration through segmentation on CT-scans in children.

MATERIAL AND METHODS

Chest-CT of 100 patients divided into males and females, aged 3-16 years, were retrospectively assessed. Subjects underwent inspiratory and expiratory CT-scans. Tracheal volume was segmented through ITK-SNAP software. Volume, length, anteroposterior, laterolateral diameters, and T1-T10 distance were measured. The percentage ratio between expiratory and inspiratory phases was calculated: significant differences according to sex for inspiratory and expiratory measurements were assessed through a one-way ANCOVA test using T1-T10 distance as covariate (p < 0.05). Differences in percentage changes according to sex and age were assessed through Mann-Whitney test and calculation of Pearson's correlation coefficient, respectively (p < 0.05).

RESULTS

No statistically significant difference according to sex was found for any measurement (p > 0.05). For the percentage ratio between inspiratory and expiratory phase, no difference was found according to sex for any measurement (p > 0.05). The percentage ratio of tracheal volume and length between expiratory and inspiratory phases showed a negative correlation with age (p < 0.05).

CONCLUSIONS

This study provides a novel contribution to the assessment of tracheal size in healthy children: future studies will verify the same measurements in patients affected by tracheomalacia to improve diagnosis.

Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model

OBJECTIVE/HYPOTHESIS

To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics.

STUDY DESIGN

Animal research study.

METHODS

Eight adult New-Zealand white rabbits were used as they approximate neonatal airway-size. The airways were measured using ETT-sizing and 3D UTE-MRI at baseline, 2 weeks post-cauterization induced SGS injury, and post-balloon dilation treatment. UTE-MR images were acquired to determine airway anatomy and motion. Airways were segmented from MR images. Cross-sectional area (CSA), major and minor diameters (D_major and D_minor ), and eccentricity were measured.

RESULTS

Post-injury CSA at SGS was significantly reduced (mean 38%) compared to baseline (P = .003) using UTE-MRI. ETT-sizing correlated significantly with MRI-measured CSA at the SGS location (r = 0.6; P < .01), particularly at the post-injury timepoint (r = 0.93; P < .01). Outer diameter from ETT-sizing (OD) correlated significantly with D_major (r = 0.63; P < .01) from UTE-MRI at the SGS location, especially for the post-injury timepoint (r = 0.91; P < .01). Mean CSA of upper trachea did not change significantly between end-expiration and end-inspiration at any timepoint (all P > .05). Eccentricity of the upper trachea increased significantly post-balloon dilation (P < .05).

CONCLUSIONS

UTE-MRI successfully detected SGS and treatment response in the rabbit model, with good correlation to ETT-sizing. Balloon dilation increased CSA at SGS, but not to baseline values. SGS did not alter dynamic motion for the trachea in this rabbit model; however, tracheas were significantly eccentric post-balloon dilation. UTE-MRI can detect SGS without sedation or ionizing radiation and may be a non-invasive alternative to ETT-sizing.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E1971-E1979, 2021.

Diagnosis and management of complete tracheal rings with concurrent tracheoesophageal fistula

OBJECTIVE

Characterize patients with complete tracheal rings and tracheoesophageal fistula (TEF) and summarize management options.

METHODS

A systematic review of patients under 18 years of age with complete tracheal rings and TEF was conducted. Authors were contacted for additional patient information and new cases were added. Patients with iatrogenic TEF and tracheal stenosis due to other causes were excluded.

RESULTS

Sixteen patients with a median (IQR) follow-up of 10 months (3-12 months) were identified. All had a distal TEF with complete tracheal rings distal to the TEF. There were 10 (63%) type C esophageal atresia + TEF (EA/TEF), and 1 (6%) type D (5 missing data). Median (IQR) airway diameter was 2 mm (1.5-2.2 mm). Complete tracheal rings were diagnosed prior to TEF repair in 5 (31.3%) patients, after ≥1 failed extubation in 3 (12.5%) patients, and intra-operatively during respiratory distress in 1 patient. Ten patients (62.5%) were intubated with an endotracheal tube and one with a 6 Fr flexible aortic canula (5 missing data). Four patients with an endotracheal tube for TEF repair developed ventilatory problems. Complete tracheal rings were repaired in 9 (56%) patients (8 slide tracheoplasty, 1 pericardial patch) and followed conservatively in 3 (19%). One patient required tracheotomy. Four patients died.

CONCLUSIONS

Complete tracheal rings with concurrent TEF is a rare entity that pose challenges for ventilatory management during operative repair. Bronchoscopy prior to TEF repair is critical to allow for proper preoperative planning.

Reconstruction of esophageal stenosis that had persisted for 40 years using a free jejunal patch graft with virtual endoscopy assistance: A case report

In this report, we present a case in which good results were achieved by treatment using a free jejunal patch graft with virtual endoscopy (VE) assistance in a patient whose swallowing had failed to improve for 40 years after he mistakenly swallowed sulfuric acid, despite pectoralis major myocutaneous flap grafting and frequent balloon dilatation surgery. During the last 20 years, virtual computed tomography imaging has improved remarkably and continues to be used to address new challenges. For reconstructive surgeons, the greatest advantage of VE is that it is a noninvasive modality capable of visualizing areas inaccessible to a flexible endoscope. Using VE findings, we were able to visualize the 3-dimensional shape beyond the stenosis. VE can also help predict the area of the defect after contracture release.

A comparison of virtual bronchoscopy versus flexible bronchoscopy in the diagnosis of tracheobronchomalacia in children

INTRODUCTION

Flexible bronchoscopy (FB) is the current gold standard for diagnosing tracheobronchomalacia. However, it is not always feasible and virtual bronchoscopy (VB), acquired from chest multi-detector CT (MDCT) scan is an alternative diagnostic tool. We determined the sensitivity, specificity, and positive and negative predictive values of VB compared to FB in diagnosing tracheobronchomalacia.

METHODS

Children aged <18-years scheduled for FB and MDCT were recruited. FB and MDCT were undertaken within 30-min to 7-days of each other. Tracheobronchomalacia (mild, moderate, severe, very severe) diagnosed on FB were independently scored by two pediatric pulmonologists; VB was independently scored by two pairs (each pair = pediatric pulmonologist and radiologist), in a blinded manner.

RESULTS

In 53 children (median age = 2.5 years, range 0.8-14.3) evaluated for airway abnormalities, tracheomalacia was detected in 37 (70%) children at FB. Of these, VB detected tracheomalacia in 20 children, with a sensitivity of 54.1% (95%CI 37.1-70.2), specificity = 87.5% (95%CI 60.4-97.8), and positive predictive value = 90.9% (95%CI 69.4-98.4). The agreement between pediatric pulmonologists for diagnosing tracheomalacia by FB was excellent, weighted κ = 0.8 (95%CI 0.64-0.97); but only fair between the pairs of pediatric pulmonologists/radiologists for VB, weighted κ = 0.47 (95%CI 0.23-0.71). There were 42 cases of bronchomalacia detected on FB. VB had a sensitivity = 45.2% (95%CI 30.2-61.2), specificity = 95.5% (95%CI 94.2-96.5), and positive predictive value = 23.2 (95%CI 14.9-34.0) compared to FB in detecting bronchomalacia.

CONCLUSION

VB cannot replace FB as the gold standard for detecting tracheobronchomalacia in children. However, VB could be considered as an alternative diagnostic modality in children with symptoms suggestive of tracheobronchomalacia where FB is unavailable. Pediatr Pulmonol. 2017;52:480-486. © 2016 Wiley Periodicals, Inc.

Inhaled Foreign Bodies: Presentation, Management and Value of History and Plain Chest Radiography in Delayed Presentation

OBJECTIVES: To assess the clinical and management aspects of tracheobronchial foreign body (FB) in children and adults; to judge the influence of the operator's experience on the outcome of the procedure and to evaluate the factors associated with delayed diagnosis of FB aspiration (FBA) in children; and to compare clinical, radiologic and bronchoscopic findings in the patients with suspected FB inhalation (FBI).

STUDY DESIGN AND SETTING: Retrospective review of a 10-year experience (from 1995 to 2005), involving a 1512-bed Mansoura university hospital and a 184-bed Mansoura emergency hospital.

MATERIAL AND METHODS: Three thousand three hundred patients underwent rigid bronchoscopy for suspected FBI between 1995 and 2005 in Mansoura, Egypt. The data were analyzed in 3 groups: the patients with negative bronchoscopy for FBI (group 1), early (group 2), and delayed diagnosis (group 3). Foreign body was removed using the rigid bronchoscope with or without using the extracting forceps (Egyptian novel technique; Sersar technique).

RESULTS: The penetration syndrome and decreased breath sounds were determined in a significantly higher number of the patients with FBI. The plain chest radiography revealed radiopaque foreign bodies (FBs) in 23.56% of all patients with FBI. Pneumonia and atelectasis were more common in the groups with negative bronchoscopy and with delayed diagnosis ( P < 0.01). The FBs were mostly of vegetable origin, such as seeds and peanuts. The Egyptian novel (Sersar) technique was used since 2004 April in 100 cases (4.62%) with a history of FBI (pins and or small rounded materials). It was successful in 73 cases of nonimpacted inhaled pins.

CONCLUSIONS: Bronchoscopy is indicated on appropriate history and on suspicion. To prevent delayed diagnosis, characteristic symptoms, and clinical and radiologic signs of FBI should be checked in all suspected cases. Because clinical and radiologic findings of FBI in delayed cases may mimic other disorders, the clinician must be aware of the likelihood of FBI.

EBM rating: C-4

The role of preoperative CT scan in patients with tracheoesophageal fistula: a review

PURPOSE

The morbidity and mortality associated with esophageal atresia with or without a fistula make it a challenging congenital abnormality for the pediatric surgeon. Anatomic factors like inter-pouch gap and origin of fistula are not taken into consideration in various prognostic classifications. The preoperative evaluation of these cases with computerized tomography (CT) has been used by various investigators to delineate these factors. We reviewed these studies to evaluate the usefulness of this investigation in the intra operative and post operative period.

MATERIALS AND METHODS

A literature search was done on all peer-reviewed articles published on preoperative computed tomography (CT) in cases of tracheoesophageal fistula using the PUBMED and MEDLINE search engines. Key words included tracheoesophageal fistula, computerized tomography, virtual bronchoscopy, and 3D computerized tomography reconstruction. Further, additional articles were selected from the list of references obtained from the retrieved publications. A total of 8 articles were selected for analysis.

RESULTS

In most of the studies, comprising 96 patients, observations noted in preoperative CT were confirmed during surgery. In a study by Mahalik et al [Mahalik SK, Sodhi KS, Narasimhan KL, Rao KL. Role of preoperative 3D CT reconstruction for evaluation of patients with esophageal atresia and tracheoesophageal fistula. Pediatr Surg Int. 2012 Jun 22. [Epub ahead of print]], in 6 patients the fistula could not be identified pre-operatively by CT. One study found a difference of 0.43 cm in the intraoperative gap length compared to that given by CT when compared to +/- 2 mm shown by another [1. Mahalik SK, Sodhi KS, Narasimhan KL, Rao KL. Role of preoperative 3D CT reconstruction for evaluation of patients with esophageal atresia and tracheoesophageal fistula. Pediatr Surg Int. 2012 Jun 22. [Epub ahead of print], 3. Ratan SK, Varshney A, Mullick S, Saxena NC, Kakkar S, Sodhi PK. Evaluation of neonates with esophageal atresia using chest CT scan. Pediatr Surg Int. 2004 Oct; 20(10):757-61.]. Only three studies showed surgical utility of pre-operative CT, and the surgical plan changed based on the CT findings.

CONCLUSION

The usefulness of pre-operative computerized tomography in cases of tracheoesophageal fistula is controversial. The safety of this technique is questionable due to limited facilities and associated radiation hazards. Further, limited information obtained which may help in changing the surgical plan can easily be managed intra-operatively by careful and meticulous surgery. Overall, the safety concerns outweigh its efficacy. Thus, the use of pre-operative CT scan cannot be generalized and protocolized as a standard of care in the management of tracheoesophageal atresia.

Virtual bronchoscopy for evaluating cervical tumors of the fetus

We report on four cases of fetal cervical tumor, comprising three lymphangiomas and one teratoma, evaluated by ultrasound and magnetic resonance imaging (MRI) between 26 and 37 weeks' gestation. The aim was to investigate the use of virtual bronchoscopy to evaluate fetal airway patency in each case. A three-dimensional (3D) model of the airway was created from overlapping image layers generated by MRI. The files obtained were manipulated using 3D modeling software, allowing the virtual positioning of observation cameras, adjustment of lighting parameters and creation of simulated 3D movies for analysis of a virtual path through the model. In all fetuses, fetal airway patency was clearly demonstrated by virtual bronchoscopy and this was confirmed postnatally. MRI with virtual bronchoscopy could become a useful tool for studying fetal airway patency in cases of cervical tumor.

THE EFFECT OF DIFFERENT LOCATIONS OF TRACHEAL STENOSIS TO THE FLOW CHARACTERISTICS USING RECONSTRUCTED CT-SCANNED IMAGE

The presence of tracheal stenosis would alter the flow path of the inhaled and exhaled air and subsequently changed the flow behavior inside the trachea and main bronchi. Therefore, it was our aim to investigate and predict the changes of flow behavior along with the pressure distribution with respect to the presence of stenosis on the tracheal lumen. In this study, actual CT scan images were extracted for flow modeling purposes. The images were then reconstructed to mimic the effect of different stenosis locations. This method overcomes the problem of the absence of actual images for different tracheal stenosis locations. The flow was subjected to different breathing situations corresponding to low, moderate and rigorous activities. The results showed that for flow over the stenosis farthest from the bifurcation, the pressure drop was insignificant for all breathing situations. At the same time, the inlet flow rate at the bifurcation showed less air flows into the right lung as compared to healthy flow conditions. On the other hand, for the flow over stenosis closest to the bifurcation, the pressure drop near the bifurcation area was very significant at high flow rate.

Role of preoperative 3D CT reconstruction for evaluation of patients with esophageal atresia and tracheoesophageal fistula

OBJECTIVE

The role of preoperative contrast-enhanced computerized tomography (CT) of chest with three-dimensional (3D) reconstructions was evaluated in neonates with esophageal atresia and tracheoesophageal fistula.

METHODS

This was a prospective study which investigated 30 cases of esophageal atresia with tracheoesophageal fistula. All patients were evaluated preoperatively with contrast-enhanced spiral CT using a low-dose CT protocol. 3D CT reconstruction images were evaluated for the type of esophageal atresia, the distance between the upper and lower esophageal pouches, origin, level and position of the fistula, and the presence or absence of any other cardiac, pulmonary or mediastinal lesions and the findings were correlated with the findings at surgery. The radiation dose for each patient was calculated using the formula-Effective dose (E) = DLP × (E/DLP)age.

RESULTS

All the 30 cases had type-C esophageal atresia with tracheoesophageal fistula as per Gross classification. The exact site of the fistula could be identified only in 26 (80 %) cases. The mean gap between the upper pouch and lower fistula was 0.95 ± 0.57 cm (range 0.2-2.8 cm) on CT scan and 1.38 ± 0.61 cm (range 0.5-3.2 cm) at surgery. On statistical analysis, the correlation was found to be significant (p < 0.0001). In addition, lung pathology (consolidation), cardiac pathology and vertebral anomaly were also detected on CT scan in some cases. The mean radiation dose for the neonates who underwent CT chest was calculated to be 1.79 mSv which is significantly high.

CONCLUSION

Though preoperative CT scan of chest has many advantages, it involves significant exposure to ionizing radiation and risk of radiation-induced cancer in the future. Additionally in 20 % of cases, the fistula could not be located on CT scan. The most common variety of esophageal atresia and tracheoesophageal fistula is Gross type C (86 %) that has low to intermediate gap (97 %) and can be anastomosed primarily. Thus, CT scan can provide good anatomical delineation, but may not help in surgical decision making. Hence, performing CT in these cases would unnecessarily expose the neonates to ionizing radiation. Therefore, there is no role for CT scan in the routine preoperative assessment of EA with distal TEF.

Application of MPVR and TL-VR with 64-row MDCT in neonates with congenital EA and distal TEF

AIM: To assess the application of multiple planar volume reconstruction (MPVR) and three-dimensional (3D) transparency lung volume rendering (TL-VR) with 64-row multidetector-row computed tomography (MDCT) in neonates with congenital esophageal atresia (EA) and distal tracheoesophageal fistula (TEF).

METHODS: Twenty neonates (17 boys, 3 girls) with EA and distal TEF at a mean age of 4.6 d (range 1-16 d) were enrolled in this study. A helical scan of 64-row MDCT was performed at the 64 mm × 0.625 mm collimation. EA and TEF were reconstructed with MPVR and TL-VR, respectively. Initial diagnosis of EA was made by chest radiography showing the inserted catheter in the proximal blind-ended esophageal pouch. Manifestations of MDCT images were compared with the findings at surgery.

RESULTS: MDCT showed the proximal and distal esophageal pouches in 20 cases. No significant difference was observed in gaps between the proximal and distal esophageal pouches detected by MPVR and TL-VR. The lengths of gaps between the proximal and distal esophageal pouches detected by MPVR and TL-VR correlated well with the findings at surgery (R = 0.87, P < 0.001). The images of MPVR revealed the orifice of TEF in 13 cases, while TL-VR images showed the orifice of TEF in 4 cases.

CONCLUSION: EA and distal TEF can be reconstructed using MPVR and TL-VR of 64-row MDCT, which is a noninvasive technique to demonstrate the distal esophageal pouches and inter-pouch distance in neonates with EA and distal TEF.

Tracheoesophageal fistula after primary repair of type C esophageal atresia in the neonatal period: recurrent or missed second congenital fistula

PURPOSE

The aim of the study is to investigate whether a tracheoesophageal fistula (TEF) found after the primary repair of type C esophageal atresia (EA) is a recannulation of the original fistula, a missed proximal fistula, or other rare foregut malformation.

METHODS

Between 2000 and 2009, 143 different types of patients with EA were admitted in our hospital. Seven patients (2 from our series, 5 referred to us by other hospitals with the history of primary repair of type C EA) had late presenting TEF. Esophagogram, 3-dimensional computed tomographic (CT) reconstruction, bronchoscopy, and reoperation were performed to confirm the TEF. Their medical records were reviewed and summarized.

RESULTS

Persistent feeding or respiratory problems were the common symptom. The mean age of the first appearance was 17 ± 26 (1-63) months. Preoperative diagnosis was made by esophagograms and bronchoscopy in 6 patients. Reoperations were performed in all patients through thoracotomy. Missed proximal TEF shown as a distinct fistula above the primary anastomosis without much adhesion was confirmed in 5 cases. A recurrent TEF was found in 1 case. A case of communicating bronchopulmonary foregut malformation was confirmed by 3-dimensional CT reconstruction and reoperation.

CONCLUSION

A missed proximal TEF after repair of EA may be misdiagnosed as a recurrent TEF. Accurate preoperative diagnosis depends on combined evaluations of radiologic contrast study, 3-dimensional CT, and bronchoscopy.

Utility of multidetector CT and virtual bronchoscopy in tracheobronchial obstruction in children

PURPOSE

The aim of this study was to evaluate the potential use of multidetector CT (MDCT) and virtual bronchoscopy (VB) in the evaluation of tracheobronchial patency in children with suspected bronchial obstruction and to compare its findings with fibreoptic/rigid bronchoscopy or surgery.

PATIENTS AND METHODS

A total of 43 children (15 girls, 28 boys) with clinically suspected bronchial obstruction underwent contrast enhanced MDCT, using an age- and weight- adjusted low dose protocol. Post-processing was performed and VB and multiplanar reformations (MPR) were obtained at the same sitting. Findings obtained at MDCT and VB were compared with fibreoptic/rigid bronchoscopy and surgery.

RESULTS

Obstructive pathology was found in 26 children, which included endoluminal foreign body, mucus plugs in 13 children, endobronchial tumour in three children and extrinsic compression (lymph node, aberrant Vessels, mediastinal cysts/tumours) of the tracheobronchial tree in 10 children. In 17 children, no obstructive lesion was identified. Excellent positive correlation was obtained, between MDCT-VB and bronchoscopy/surgery, however, in one child with endobronchial obstruction caused by tracheitis, low dose MDCT-VB was normal, but bronchoscopy revealed granularity and plaques.

CONCLUSION

MDCT-Virtual bronchoscopy is useful in evaluating bronchial stenosis and obstruction caused by both endoluminal pathology and external compression and has the advantage of looking beyond stenosis. Its main application lies in providing the exact location of suspected foreign body, prior to bronchoscopy. However, it fails to disclose exact nature of obstructing pathology.

Advanced visualization of airways with 64-MDCT: 3D mapping and virtual bronchoscopy

OBJECTIVE

The purpose of this pictorial essay is to review the current role of virtual bronchoscopy and 3D imaging of the airways in clinical practice.

CONCLUSIONS

Virtual bronchoscopy produces high-resolution images of the tracheobronchial tree and endobronchial views that simulate the findings at conventional bronchoscopy. Interest in virtual bronchoscopy is increasing as a result of improvements in computer hardware and software and advances in MDCT that allow acquisition of isotropic data.

Preoperative evaluation of the trachea in a child with pulmonary artery sling using 3-dimensional computed tomographic imaging and virtual bronchoscopy

Pulmonary artery sling is frequently accompanied by tracheal anomalies other than local compression, including focal/segmental or extensive stenosis (ring-sling complex). Recent advances in computed tomography technology, such as multidetector computed tomography with 3-dimensional imaging (3-D) and virtual bronchoscopy (VB), offer important and accurate information of the entire tracheobronchial tree. We report on the value of 3-D imaging and VB in the preoperative assessment of a 4-year-old child with pulmonary artery sling and long segment tracheal stenosis owing to complete cartilaginous rings; we suggest that 3-D imaging and VB are important contributions in this assessment.

Utilization of low-dose multidetector CT and virtual bronchoscopy in children with suspected foreign body aspiration

BACKGROUND

Foreign body aspiration is common in children, especially those under 3 years of age. Chest radiography and CT are the main imaging modalities for the evaluation of these children. Management of children with suspected foreign body aspiration (SFBA) mainly depends on radiological findings.

OBJECTIVE

To investigate the potential use of low-dose multidetector CT (MDCT) and virtual bronchoscopy (VB) in the evaluation and management of SFBA in children.

MATERIALS AND METHODS

Included in the study were 37 children (17 girls, 20 boys; age 4 months to 10 years, mean 32 months) with SFBA. Chest radiographs were obtained prior to MDCT in all patients. MDCT was performed using a low-dose technique. VB images were obtained in the same session. Conventional bronchoscopy (CB) was performed within 24 h on patients in whom an obstructive abnormality had been found by MDCT and VB.

RESULTS

Obstructive pathology was found in 16 (43.25%) of the 37 patients using MDCT and VB. In 13 of these patients, foreign bodies were detected and removed via CB. The foreign bodies were located in the right main bronchus (n = 5), in the bronchus intermedius (n = 6), in the medial segment of the middle lobe bronchus (n = 1), and in the left main bronchus (n = 1). In the remaining three patients, the diagnosis was false-positive for an obstructive pathology by MDCT and VB; the final diagnoses were secretions (n = 2) and schwannoma (n = 1), as demonstrated by CB. In 21 patients in whom no obstructive pathology was detected by MDCT and VB, CB was not performed. These patients were followed for 5-20 months without any recurrent obstructive symptomatology.

CONCLUSIONS

Low-dose MDCT and VB are non-invasive radiological modalities that can be used easily in the investigation of SFBA in children. MDCT and VB provide the exact location of the obstructive pathology prior to CB. If obstructive pathology is depicted with MDCT and VB, CB should be performed either for confirmation of the diagnosis or for the diagnosis of an alternative cause for the obstruction. In cases where no obstructive pathology is detected by MDCT and VB, CB may not be clinically useful.

Value of virtual tracheobronchoscopy and bronchography from 16-slice multidetector-row spiral computed tomography for assessment of suspected tracheobronchial stenosis in children

PURPOSE

To evaluate the value of dose-reduced 16-slice multidetector-row spiral computed tomography (16-MDCT) using virtual tracheobronchoscopy (VTB) and virtual bronchography (VBG) in children with suspected tracheobronchial stenosis.

MATERIALS AND METHODS

12 children (4 d to 3 years, body weight 1.2 kg to 13.5 kg) with stridor and suspected tracheobronchial stenosis were examined by contrast-enhanced low-dose 16-MDCT. Conventional axial slices, MPRs, VTB, and VBG were calculated. Image findings were correlated with the results of fiberoptic bronchoscopy (12 out of 12) as a gold standard and subsequent surgery (8 out of 12).

RESULTS

VTB and VBG demonstrated the fiberoptic bronchoscopically suspected tracheal stenosis in 11 of 12 children due to vascular compression because of the brachiocephalic trunk (6), a double aortic arch (2), a vascular compression of the left main bronchus (2), and a right aberrant subclavian artery (1). Eleven out of 12 stenoses were correctly depicted by conventional axial slices, MPRs, VTB, and VBG. Dose reduction was 79 to 85.8% compared to a standard adult chest CT.

CONCLUSION

Dose-reduced 16-MDCT with the use of VTB and VBG is effective for the evaluation of tracheobronchial stenosis in children and correlates well with fiberoptic bronchoscopy.

Use of 3-Dimensional Computed Tomography Reconstruction Studies in the Preoperative Assessment of Patients Undergoing Balloon Dilatation for Tracheobronchial Stenosis

BACKGROUND

Balloon dilatation (BD) is a useful method of treating tracheobronchial stenosis (TBS); however, accurate preoperative identification of the lesion is difficult. Three-dimensional computed tomography (3D-CT) is an imaging method that may allow more accurate definition of the lesion(s) preoperatively.

STUDY OBJECTIVE

It is the aim of this study to present our finding using 3D-CT as a part of the preoperative evaluation of patients with TBS undergoing BD.

METHODS

We studied a prospective case series of 17 consecutive patients who underwent 29 BDs for TBS from a variety of benign and malignant causes at a tertiary care hospital. All patients had a preoperative spiral CT; these data were processed by a software program, VIDA, which was developed at this institution, and 3D-CT reconstruction images of the TBS were created. This enabled accurate preoperative anatomic definition of the lesion. The patients subsequently underwent BD.

RESULTS

All 17 patients had lesions identified with 3D-CT. Six patients had tracheal lesions and 12 patients had main stem lesions. One patient had combined tracheal and main stem lesions and 2 other patients had bilateral main stem lesions. Nine out of 17 patients required only one BD. One patient had a failed BD. The remaining 6 patients required more than one BD for optimal results (up to a maximum of 4). The follow-up period ranged from 1 to 34 months.

CONCLUSIONS

3D-CT offers accurate definition of TBS, including anatomic location, number of lesions present and status of airway distal to lesion. In this study, all preoperative lesions were correctly identified prior to BD.

Multidetector-row computed tomography three-dimensional volume reformatted 'transparency' images to define an upper pouch fistula in oesophageal atresia

Oesophageal atresia (OA) is an important congenital malformation in which prompt diagnosis and appropriate management can significantly improve outcome. The surgical approach to repair of OA and associated tracheo-oesophageal fistulae (TOF) depends upon correct evaluation of the tracheobronchial tree. Three-dimensional imaging of the tracheobronchial tree using CT data to produce shaded surface displays and virtual bronchoscopy has been reported in paediatric and neonatal patients with OA and TOF and is described as accurate and helpful, non-invasively facilitating the appreciation of complex anatomy prior to surgery. We describe the technique of reconstructing 3D volume-reformatted 'transparency' images using insufflated air as a negative contrast medium. This technique is fast, accurate and produces high-quality images that are easy to reproduce.

Low-dose MDCT and virtual bronchoscopy in pediatric patients with foreign body aspiration

OBJECTIVE

The purpose of this study was to investigate the potential use of low-tube-current MDCT virtual bronchoscopy for the evaluation of children with suspected foreign body aspiration.

SUBJECTS AND METHODS

Low-tube-current MDCT was performed in 23 patients (10 girls, 13 boys) with a mean age of 3.3 years (9 months-13 years) with suspicion of foreign body aspiration. Chest radiographs were obtained before CT was performed. MDCT was performed using 25- to 50-mA tube currents. MDCT virtual bronchoscopy images were obtained. Neither sedation nor IV contrast medium was used during CT scanning. All patients underwent endoscopic evaluation within 24 hr after MDCT was performed. MDCT virtual bronchoscopy findings were retrospectively compared with the results of rigid bronchoscopy.

RESULTS

The mean tube current was 35 mA (range, 25-50 mA). Imaging quality was excellent in nine studies (39%), good in 12 studies (52%), and poor in two studies (9%). Motion artifacts were present on several slices in five examinations. In 15 patients, all foreign bodies detected by conventional bronchoscopy were also revealed on MDCT virtual bronchoscopy. The foreign body was in the right main bronchus in six patients, in the bronchus intermedius in one patient, and in the left main bronchus in eight patients. No discordance was found between the two techniques. MDCT revealed hyperaeration of the ipsilateral lung in five patients, atelectasis in five patients, infiltration in three patients, and infiltration and bronchiectasis in two patients; it showed infiltration in four patients and atelectasis in one of eight patients without a foreign body detected. There were no abnormal findings in three patients.

CONCLUSION

Evaluation of foreign body aspiration of the airway in children can be accomplished by using a low-tube-current MDCT protocol. It may be useful both in showing the exact location of a foreign body before bronchoscopy and in ruling out a foreign body in patients with a low level of suspicion and normal or nonspecific findings on chest radiography.

Sonographic evaluation of oesophageal atresia and tracheo-oesophageal fistula

BACKGROUND

Oesophageal atresia and tracheo-oesophageal fistula (TOF) in neonates and young infants is routinely diagnosed using frontal and lateral chest radiographs in the former and fluoroscopic studies in the latter.

OBJECTIVE

The aim of the study was to assess whether a combination of mediastinal and abdominal sonography can be used for the diagnosis of these anomalies in paediatric patients.

MATERIAL AND METHODS

Sonography was performed in 16 neonates (age range 1-20 days; mean 4 days) with radiologically confirmed oesophageal atresia or isolated TOF. A small volume of saline solution was instilled into the blind upper oesophageal pouch to document its extension.

RESULTS

Sonography identified 11 neonates with the most common type of oesophageal atresia (type IIIb), one patient with type II and one with type IIIa anomaly. The length of the upper pouch and the features of its wall were clearly documented in all cases. In one case, two upper TOF were first diagnosed by mediastinal sonography and later confirmed by fluoroscopy. In two of three cases with isolated TOF, the fistula could be located sonographically by detecting moving air bubbles. In all cases the position of the aortic arch, as well as associated malformations, could be documented during a single US examination.

CONCLUSIONS

These results indicate that mediastinal sonography is a useful tool for the diagnosis of oesophageal atresia and, if air bubbles can be detected, isolated TOF.

Is Virtual Bronchoscopy an Efficient Diagnostic Tool for the Thoracic Surgeon?

Virtual bronchoscopy has emerged over the past decade as a potentially complementary investigation to conventional bronchoscopy in the diagnosis, grading, and monitoring of pulmonary disease. A meta-analysis reporting on the use of virtual bronchoscopy has not yet been performed. The primary aim of this study is to evaluate its diagnostic accuracy compared to the gold standard investigation of conventional bronchoscopy (fiberoptic or rigid). Quantitative data synthesis included the calculation of independent sensitivity and specificity, construction of summary receiver operating characteristic curves, pooled analysis, and sensitivity analysis. Seventeen studies were identified comprising 459 patients. The calculated pooled sensitivity was 84% (95% CI, 78% to 89%), specificity 75% (95% CI, 62% to 85%) and area under the curve was 0.92, which shows good diagnostic performance. Meta-analysis confirms virtual bronchoscopy is very discriminating in the evaluation of patients with significant airway stenosis that is due to a wide spectrum of pathologic conditions. It can potentially have a beneficial role in selected thoracic patients (with bronchoesophageal fistulas, postlung transplantation, anastomoses, and suspected foreign body aspiration).

Long-term complications of congenital esophageal atresia and/or tracheoesophageal fistula

Congenital esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) are common congenital anomalies. Respiratory and GI complications occur frequently, and may persist lifelong. Late complications of EA/TEF include tracheomalacia, a recurrence of the TEF, esophageal stricture, and gastroesophageal reflux. These complications may lead to a brassy or honking-type cough, dysphagia, recurrent pneumonia, obstructive and restrictive ventilatory defects, and airway hyperreactivity. Aspiration should be excluded in children and adults with a history of EA/TEF who present with respiratory symptoms and/or recurrent lower respiratory infections, to prevent chronic pulmonary disease.

Grading Airway Stenosis Down to the Segmental Level Using Virtual Bronchoscopy

OBJECTIVE

To assess the sensitivity of noninvasive virtual bronchoscopy based on multirow detector CT scanning in detecting and grading central and segmental airway stenosis using flexible bronchoscopic findings as the reference standard.

MATERIALS AND METHODS

In a blinded controlled trial, multirow detector CT virtual bronchoscopy and flexible bronchoscopy were used to search for and grade airway stenosis in 20 patients. CT scan data were obtained with a multirow detector CT scanner using 4 x 1 mm collimation. Flexible bronchoscopy findings were graded by a pulmonologist and served as the reference standard for 176 central airway regions (ie, trachea, main bronchi, and lobar bronchi) and 302 segmental airway regions. The extent of airway narrowing was categorized as grade 0 (no narrowing), grade 1 (< 50%), or grade 2 (> or =50%).

RESULTS

Flexible bronchoscopy revealed 30 stenoses in the central airways and 10 in the segmental airways. Virtual bronchoscopy detected 32 stenoses in the central airways (sensitivity, 90.0%; specificity, 96.6%; accuracy, 95.5%) and 22 in the segmental airways (sensitivity, 90.0%; specificity, 95.6%; accuracy, 95.5%). The number of false-positive findings was higher in the segmental airways (13 false-positive findings) than in the central airways (5 false-positive findings), which caused a lower positive predictive value for the segmental airways (40.9%) than for the central airways (84.4%). Flexible and virtual bronchoscopic gradings correlated better for central airway stenosis (r = 0.87) than for segmental airway stenosis (r = 0.61).

CONCLUSION

Although a high sensitivity was found for the detection of both central and segmental airway stenosis, the number of false-positive findings was higher for segmental airways. However, noninvasive multirow detector CT virtual bronchoscopy enables high-resolution endoluminal imaging of the airways down to the segmental bronchi.

Diagnosis of a proximal tracheoesophageal fistula using three-dimensional CT scan: a case report

Missed proximal tracheoesophageal fistulas (TEF) after repair of an esophageal atresia (EA) with distal TEF are rare. The diagnosis usually is made on the basis of bronchoscopy and esophagoscopy, which can be inaccurate. Recent advances in computerized tomography (CT) have allowed saggital, coronal, and 3-dimensional reconstruction of any structure or organ. The authors report a case in which 3-dimensional CT was used to assist in the diagnosis of a missed proximal TEF in a 16-year-old girl.

[Low dose multislice CT in the pediatric patient]

In the past years, multislice CT (MS-CT) has become an important diagnostic modality for the radiological evaluation of the thorax in children and adolescents. However, the higher stochastic radiation risks in pediatric patients, as compared to adults, necessitate a prudent use of MS-CT. This article presents an overview of the benefits of multislice CT and a variety of possibilities for radiation reduction in pediatric patients of different ages.

CT virtual bronchoscopy in the evaluation of children with suspected foreign body aspiration

OBJECTIVE

Computed tomography (CT) virtual bronchoscopy is a noninvasive technique that provides an internal view of trachea and major bronchi by three-dimensional reconstruction. The aim of this study was to investigate the usefulness of virtual bronchoscopy in the evaluation of suspected foreign body aspiration in children.

MATERIALS AND METHODS

Twenty-three children (12 girls, 11 boys) with a mean age of 2.4 years (8 months-14 years) who were admitted to emergency room with a suspicion of foreign body aspiration were included in this study. Chest radiograms, spiral computed tomography scans and virtual bronchoscopy images were obtained. Then, rigid bronchoscopy was performed within 24 h.

RESULTS

CT virtual bronchoscopy and conventional bronchoscopy revealed the location of the foreign body in seven patients. It was in the right main bronchus in four patients, in the right lower lobe bronchus in one patient, and in the left main bronchus in two patients. There was no discordance between two modalities. CT examination revealed hyperaeration of the ipsilateral lung in four patients, hyperaeration of the ipsilateral lung and mediastinal shift in one patient and bronchiectatic changes in one patient. CT detected no additional finding in one patient with a foreign body in the right main bronchus. In 10 of 16 patients without foreign body, CT examination demonstrated atelectasis, infiltration, peribronchial thickening, and paratracheal lymphadenpoathy.

CONCLUSION

Helical CT scanning with virtual bronchoscopy should be performed in only selected cases with suspected foreign body aspiration. When the chest radiograph is normal and the clinical diagnosis suggests aspirated foreign body, helical CT and virtual bronchoscopy can be considered in order to avoid needless rigid bronchoscopy.

Long-term complications of artificial airways

In summary, long-term complications of artificial airways are rare but important sequelae of artificial airways. Many of the potential long-term complications of translaryngeal intubation and tracheotomy are similar and overlapping. Although most patients who undergo these procedures tend to tolerate them without difficulties, significant morbidity and mortality may occur. Identifying the exact cause of the complication may not be possible at times, due to the multiple risk factors involved in the pathogenesis. It is hoped that understanding these potential complications will lead to a more vigilant preventive measures during the institution of long-term artificial airways and a judicious early search for the underlying pathology when a complication is suspected.

Virtual endoscopy in the diagnosis of an adult double tracheal bronchi case

We report a case of ipsilateral double tracheal bronchi supplying a tracheal lobe in a 42-year-old man, who presented with a 10-year history of recurrent respiratory infections. Diagnosis was established by chest computed tomography (CCT), virtual endoscopy and bronchoscopy. Both bronchi were surgically resected along with the right upper lobe of the lung and the associated tracheal lobe. To our knowledge, this is the first report of ipsilateral double tracheal bronchi in the adult life to be diagnosed and treated on the basis of modern radiological techniques and especially virtual endoscopy findings.