Clinical trial NCT02620319: Biodegradable Stents in the Management of Stenoses of the Large Airways
Official title: Biodegradable Stents in the Management of Stenoses of the Large Airways
Study type: INTERVENTIONAL
Overall status: SUSPENDED
Phase: NA
Conditions: Tracheal Stenosis
Keywords: bronchoscopy
polydioxanone
absorbable implants
stents
Lead sponsor: Thomayer University Hospital
Sponsor class: OTHER
Collaborators: name: Ministry of Health, Czech Republic
name: University Hospital Olomouc
name: University Hospital, Motol
First posted: 2015-12-03
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: The objective of this project is to determine whether biodegradable polydioxanone stents are efficient in the treatment of adult patients with tracheobronchial stenoses.

Detailed description: Background:

The ideal airway stent has yet to be developed. Biodegradable (BD) stents are made of knitted polymer fibers that degrade when placed in the body; extraction of the device is, therefore, unnecessary. Several in vitro and in vivo studies of tracheal BD stents composed of various materials have been conducted.

Polydioxanone is a biodegradable polymer in the polyester family, which has attracted a lot of interest due to its exquisite biocompatibility and is currently available on the market in the form of absorbable suture material. It is degraded by hydrolysis (of its ester bonds), which is accelerated under low potential of Hydrogen (pH) conditions, into harmless degradation products. Polydioxanone tracheal stents appear to be well tolerated by the tracheal mucosa, retain their mechanical strength for as long as 6 weeks, and, in animal models, completely degrade after approximately 15 weeks. They have been successfully used in humans as mechanical support for tracheal transplants, during treatment of obstructive airway complications after lung transplantation, and in children with airway stenosis.

Hypotheses:

Biodegradable stents can be used in adult patients as a temporary mechanical support of narrowed airways, they allow healing of the airways or secure the airways until another (anticancer, anti-inflammatory) therapy manages the cause of the narrowing. Biodegradable stents are expected to have advantages over classical stents, namely good biocompatibility, fair adaptation to the anatomy of the airways, they do not limit the transportation of secretions substantially.

Objectives:

The primary objective of this study is to show that BD stents can be safely used and are effective in the treatment of adult patients with tracheal narrowings.

The secondary objectives are: to observe and analyze mucosa - BD stent interaction, to assess degradation of stents and its consequences.

Design:

Prospective interventional study conducted in three hospitals in the Czech Republic.

Methods:

The investigators intend to enroll adult participants suffering from significant large airway stenoses in which the stenting is generally considered to be effective. Every participant is reviewed by at least two interventional pulmonologists and a thoracic surgeon to determine the best therapeutic option. Bronchoscopy and computed tomography of the trachea is considered essential to confirm the diagnoses. All participants sign an informed consent form prior to undergoing the procedure.

During the stent implantation, the trachea is intubated with a rigid bronchoscope, participants are placed under total intravenous anesthesia and jet ventilation. The investigators intend to use self-expandable, biodegradable, polydioxanone tracheal stents, the SX-ELLA Stent DV Tracheal (DV Stent), manufactured by ELLA-CS, s.r.o., Hradec Kralove, Czech Republic. Stent is standardly equipped with radiopaque markers at distal and proximal end. It is delivered in sterile packed, separately from original delivery system into which the stent immediately before implantation is placed. As mentioned, stent is made of synthetic polymer - braided polydioxanone fiber widely used for absorbable surgical suture. The suture has successfully been used in the surgery, orthopedics and dental surgery for more than 25 years. It is known that the material is subjected to the bulk hydrolytic degradation in the body. No toxic substances arise within the degradation process. The ultimate degradation substance is 2-hydroxyacetic acid that is finally metabolized to water and carbon dioxide. The data about local reaction produced by polydioxanone implants, incl. buried sutures are contradictory. Majority of them report very low tissue reaction.

The first bronchoscopy follow up is carried out during the first post-implantation week, additional follow-ups (including clinical evaluation, bronchoscopy, basic spirometry, and chest X-ray if needed) are performed on a monthly or as-needed basis. If the restenosis threatens, the participant can be given another polydioxanone stent, as well as, he or she can be treated using mechanical removal of obstacles, balloon dilation, laser therapy and electrocautery.

Results are analyzed continuously, final evaluation is intended to be performed after reaching a sufficient number of participants. This includes statistical analysis of overall results in participants after complete stent degradation, assessment of major clinical signs and functional parameters, and especially, evaluations of endoscopic findings.

Eligibility criteria: Inclusion Criteria:

* significant large airway stenoses
* benign tracheobronchial stenosis of any origin in participants who can not go for surgery, or who refuse surgical treatment
* benign tracheobronchial stenoses of any origin when the surgery is planed after some delay, benign tracheobronchial stenoses when the effect of anti- inflammatory or anti-infective treatment is expected
* malignant tracheobronchial stenoses due to extrinsic compression when exhausted curative modalities
* malignant stenoses from extrinsic compression in participants undergoing the actinotherapy or receiving systemic anticancer therapy

Exclusion Criteria:

* stenoses of any origin which can be treated primarily surgically
* stenoses caused by intraluminal growth of tumor, tracheoesophageal or bronchoesophageal fistulas
* pregnancy

Primary outcomes:
measure: airway patency during the presence of the stent in the airways
timeFrame: residence time of the stent in the airways, i.e. as long as no stent material is found, up to 180 days after implantation, since then the stent is not considered to provide any mechanical support
Secondary outcomes:
measure: number of complications: infection, bleeding, migration, obstructive granulation tissue formation, sudden restenosis (of any origin, unexpected in relation to the degree of the stent degradation)
timeFrame: residence time of the stent in the airways (i.e. as long as no stent material is found, up to 180 days after implantation, since then the stent is not considered to provide any mechanical support) and 6 months thereafter
measure: evaluation of forced expiratory volume in 1 second (FEV1)
timeFrame: residence time of the stent in the airways (i.e. as long as no stent material is found, up to 180 days after implantation, since then the stent is not considered to provide any mechanical support) and 6 months thereafter
measure: evaluation of forced vital capacity (FVC)
timeFrame: residence time of the stent in the airways (i.e. as long as no stent material is found, up to 180 days after implantation, since then the stent is not considered to provide any mechanical support) and 6 months thereafter
measure: airway patency after complete degradation of the stent or loss of majority support functions
timeFrame: six months, beginning after identifying the complete degradation of the stent or 180 days after implantation
Other outcomes:
Locations:
city: Olomouc
country: Czechia
facility: Department of Respiratory Diseases and Tuberculosis, University Hospital Olomouc
city: Prague
country: Czechia
facility: Department of Respiratory Medicine, Thomayer Hospital
city: Prague
country: Czechia
facility: Department of Pneumology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital
Study officials:
affiliation: Department of Respiratory Medicine, Thomayer Hospital, Videnska 800, 140 59 Praha 4
name: Ludek Stehlik, MUDr.
role: PRINCIPAL_INVESTIGATOR
affiliation: Department of Pneumology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital
name: Miloslav Marel, Prof. MUDr.
role: STUDY_DIRECTOR
affiliation: Department of Respiratory Diseases and Tuberculosis, University Hospital Olomouc
name: Vitezslav Kolek, Prof. MUDr.
role: STUDY_DIRECTOR
affiliation: Department of Respiratory Medicine, Thomayer Hospital, Videnska 800, 140 59 Praha 4
name: Martina Vasakova, Prof. MUDr.
role: STUDY_DIRECTOR
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citation: Stehlik L, Guha D, Anandakumar S, Taskova A, Vasakova MK. Biodegradable tracheal stents: our ten-year experience with adult patients. BMC Pulm Med. 2024 May 15;24(1):238. doi: 10.1186/s12890-024-03057-y.