There are two categories of esophageal stricture in children: acquired and congenital.
The development of benign esophageal stricture is based on significant fibromuscular
alterations, inflammation in residual muscle layers and a deposition of collagen based on
an inflammatory process . In children, these changes are most common in the context of a
postoperative anastomotic stenosis in the case of esophageal atresia (usually type IIIb
according to Vogt), as well as after caustic injury, peptic stricture and eosinophilic
esophagitis. Rarely, children are born with congenital esophageal stricture. Therapeutic
radiation can lead to stenoses requiring dilation. Likewise, children suffering from
epidermolysis bullosa can suffer from esophageal stenosis. In rare cases, the ingestion
of a foreign body in children causes symptomatic stenosis as a buried foreign body
covered by esophageal hyper granulated tissue. Malignant stenosis is not considered in
this study, as its treatment is different.
There are different options for endoscopic esophageal dilations of clinically relevant
esophageal strictures, which promise effective treatment. Relevant strictures are usually
noticed by dysphagia.
One possible dilation method uses the Savary-Gilliard bougies. These are wire-guided
polyvinyl dilators. The advancement of the wire is performed under radiological
fluoroscopy. Once the guide wire is placed into the stomach, the dilator is passed over
the guidewire, lubricated, and pushed over the stenosis in order to dilate the stenotic
area. There are also non-guidewire bougie dilators. Longitudinal shearing force and
radial force occurs when the dilator passes across the stenotic area. Initially, the size
of the dilator that corresponds to the diameter of the stenosis is used. The same
procedure is then followed stepwise with a larger dilator of 1mm, respectively. It is
generally recommended not to increase the dilator size more than 3mm in a single session.
A major disadvantage of this method is the exclusively tactile control of the dilation.
At the end of the Bougie dilation, the result should be checked by reinserting the
endoscope to rule out deeper mucosal injuries and persistent bleeding.
Furthermore, there is experience in the treatment of esophageal stenosis in children with
balloon dilations. The balloon is inserted either blind or under endoscopic control, The
balloon is then mostly inflated to 1 mm beyond the estimated stenosis diameter and the
pressure is maintained for 1 minute or less. The dilation may be controlled
radiologically or endoscopically. A dilation up to 5mm above the initial stricture
diameter may not increase the risk of perforation. Only radial forces arise. Here, too,
insufficient visual control is to be criticized. In particular, the distal area of the
stenosis cannot be viewed during the procedure, or only with difficulty. In addition to
the poor visual control, there is no tactile control of the dilation, since the volume of
liquid applied to the balloon determines the diameter. Furthermore, there is no standard
protocol for the stepwise dilation that is required for treating children at different
ages. Finally, small esophageal balloons specifically for small children are missing,
which is why balloon catheters from other areas and indications are used (e.g. urological
balloon catheters, biliary catheters), respectively.
Due to the severely restricted visual control of the dilation with the current dilation
techniques, a conical cap made of transparent plastic was developed that can be attached
to the tip of standard endoscopes, the BougieCap (Ovesco, Tübingen). The cap is a
single-use product, available in different outer diameters (7- 16mm) and offers direct
visual and tactile control upon introduction into the upper gastrointestinal tract under
visual and tactile control. The advantage of this technique is that the endoscope acts as
a carrier of the radial and longitudinal force vectors for the dilation. A comparable
technique is one with the optical dilator, a clear, over-the-scope bougie with sequential
dilating segments. However, the limitation of this optical dilator is that it can only be
used for the dilation of relatively large stenoses (from 15mm) due to the large diameter.
A main reason why the optical dilator is not suitable for children.
There are currently no studies in the literature investigating the use of the BougieCap
technique for treating benign esophageal strictures in children.
The aim of this randomized controlled pilot study is to demonstrate the probable efficacy
of the BougieCap technique, the improvement of patient and operator dependent conditions
and the absence or reduction of related adverse events such as perforations, bleeding,
infections as well as the number of dilation sessions and intervals, compared to the
above mentioned other techniques.
The BougieCap is an endoscopic attachment cap for bougienage/dilatation of stenoses and
strictures of the upper gastrointestinal tract. No specific restrictions based on age,
weight, health status or ethnicity. The decision on whether a patient is eligible for
treatment with the product lies solely with the intended user. The BougieCap Ovesco is a
medical device primarily composed of the cap and the adhesive tape that may come into
contact with tissues (mainly Oesophagus mucosa) or bodily fluids (salive) during its
application. As per regulatory standards, it's crucial to note that this device does
not contain pharmaceuticals, human or animal tissues, their derivatives, or any other
biologically active substances.