What is ETA therapy ?
In ETA™ (Endoscopic Topical Application™) therapy, an endoscope equipped with apparatus consist of 〈an injection tube with a liquid absorbing material (retaining material) attached to the tip for injecting and applying drug solutions〉, 〈an aspiration tube appropriate to the injection tube〉 and 〈an assisting device for moving and fixing these tubes in the endoscope body〉 are used. In addition to these medical instruments, appropriate control of the injector and aspiration machine connected to the injection and aspiration tubes, respectively, ensures that the liquid drug is applied to and permeated into the desired local surface under the monitoring of an endoscope.
By using a bladder endoscope equipped with the medical apparatus for ETA therapy (shown as an example of a prototype) as shown in the figure below, it becomes possible to apply medicines such as local anesthetics and silver nitrate in the required amount to specific areas of the bladder mucosa, which is rich in sensory nerves related to urinary frequency, nocturia, and bladder pain.
Appearance of the medical apparatus for ETA therapy (shown as an example of a prototype)
① A tip of an injection tube for injecting and applying drug liquid with a circular liquid absorbing and retaining material attached to the tip. The injection tube is inserted into the corresponding aspiration tube.
② The above-mentioned injection tube moved forward relative to the aspiration tube.
③ An assisting device for moving and fixing the injection tube and aspiration tube, used by attaching it to the endoscope.
In ETA therapy, the appropriate amount of drug solution can be appropriately applied to the mucosal surface and lesion area in the vesico-luminal organ (under air perfusion), and excess drug solution can be appropriately aspirated to prevent the injected drug solution from dripping. This enables a novel endoscopic treatment that involves topical administration. In general, when applying relatively high concentration drugs or drugs with strong effects that are difficult to intraluminal injection or spraying to the mucosal surfaces of the bladder or large intestine, etc., and to ensure treatment only to the necessary areas, it is necessary to administer the liquid in such a way that it does not spread or drip into unintended surrounding areas. ETA therapy is considered to be very useful in such cases.
Furthermore, in ETA therapy, the moisture adhering to the surface of the mucous membrane and lesion at the application target site is thoroughly suctioned out through a liquid absorbent material before the application begins, allowing the medicine injected from the injection tube to remain at its high concentration on the application. This is the advantage of being able to apply the liquid medicine more effectively in ETA therapy. For example, it is known that the surface of the bladder mucosa is covered with a layer of glycosaminoglycan (GAG), which makes the mucosal surface slippery and acts as a barrier. By removing as much adhering moisture as possible from the site using suction, it is expected to improve the non-adherence of the medicine at the site and prevent the applied medicine from diluting.
As described above, ETA therapy uses a relatively safe and easy technique of application with liquid medicine and can be expected to efficiently and effectively produce therapeutic effects locally at the affected area. Conventional endoscopic treatment focuses on modalities such as “Cauterizing” (electrocautery), “Cutting” (electroablation), and “Injecting” (submucosal/intramuscular injection of medicine) the affected lesion. However, a new treatment modality called “Applying” (liquid medicine application to the lesion) based on ETA therapy has been developed, expanding the options of treatment strategies for endoscopic diseases.
On the other hand, endoscopic examination and treatment continue to expand their role as minimally invasive medicine in various medical fields. ETA therapy is expected to use not only in the bladder and urethra, but also in the gastrointestinal tract, respiratory tract, otorhinolaryngology, joint cavities, etc.