Stents absorbibles y sistema de implantación de stent traqueal absorbible en modelo animal.

Los stents son dispositivos artificiales que se introducen en la luz de una estructura tubular para proporcionar soporte en caso de obstrucción, estenosis o bloqueo y mantener así el flujo habitual. Comúnmente se implantan en vasos sanguíneos, uréteres, vías biliares, árbol traqueobronquial o tubo gastrointestinal, y los materiales usados son derivados de plásticos o metales, y están recubiertos o no con medicamentos. A pesar de sus numerosas ventajas, en patologías de curso pasajero supone un gran inconveniente su extracción o en su defecto la permanencia de un cuerpo extraño en el cuerpo, pudiendo ser causante de futuras obstrucciones. Desde hace unos años se han aprobado los stents absorbibles o biodegradables, fabricados con biopolímeros como el PLLA o la polidoxanona, entre otros, o aleaciones de metales, fundamentalmente de magnesio y hierro; materiales que son inocuos para el organismo, capaces de degradarse completamente en un determinado periodo de tiempo, hasta que la estructura dañada se repare y retome su función. Aunque los stents absorbibles tienen un gran futuro en la medicina, aún hacen falta muchas investigaciones para perfeccionar algunas características, como su fuerza radial o la velocidad de degradación. Actualmente ya se están aplicando en diferentes localizaciones para la resolución de enfermedades como la arterial coronaria, la estenosis esofágica, la anastomosis colorrectal, la estenosis ureteral, etc. Pero en otros casos no hay todavía una solución lo suficientemente resolutiva como es el caso de la vía aérea. Por ello, se describe y pone a prueba el método de implantación de un stent traqueal absorbible en conejos (Oryctolagus cuniculus), mediante vía percutánea. Los resultados son satisfactorios, ya que parece un método sencillo y fácil, que podría aplicarse en el árbol traqueobronquial de pacientes. Palabras clave: stent; estenosis; stent absorbible; traqueal

New tracheal stainless steel stent pilot study: twelve month follow-up in a rabbit model

Background Canine tracheal collapse is a complex airway pathology without promising treatment results. Currently nitinol stents are the best surgical option; however, some professionals are doubting if stent placement is the best option due to the associated complications. Objective Determine the technical feasibility, safety, and long-term follow-up after the implantation of a new tracheal stent designed for canine tracheal collapse. Methods Thirteen healthy, adult female New Zealander rabbits were involved in this pilot study.A new intra-tracheal device (Reference number 902711 patent registered as CasMin-Twine) was implanted in ten animals. Deployment was performed under general anesthesia, making a puncture incision via a 21 Gauge needle in the intra-tracheal space where the stent was introduced with a screwing process. The device was fixed to the tracheal wall with a non-absorbable suture. Computerized Tomography (CT) and an endoscopy to study structural abnormalities were performed after 30, 90 and 365 days after stent placement. Results Technical and clinical success was 100%. There was no significant change in behavior or respiratory disorders. CT studies showed no significant alterations. After the 30 days, 60% of the animals showed partial endothelization in the endoscopy study, and only one animal still presented partial endothelization after 12 months. Mucus accumulation was only present in 40% of cases and classified as low, without respiratory consequences. Only one animal presented a single granuloma at caudal stent tip. Conclusions This new tracheal stent (CasMin-Twine) is an effective and safe procedure with promising results, and also shows the possibility of removing the device after endothelization has been produced. New studies should be carried out to evaluate the effectiveness in patients with tracheomalacia. Clinical Significance/Impact This new product can give veterinarians a new option of treatment for this complicated pathology. Minimizing specific equipment for its deployment, CasMin-Twine will be more accessible for all professionals

A new airway spiral stent designed to maintain airway architecture with an atraumatic removal after full epithelization - Research of feasibility and viability in canine patients with tracheomalacia

Objective: Surgical management of tracheomalacia is a challenge, with current treatments still presenting numerous complications. In the field of veterinary medicine, this same pathology is present in a significant number of dogs. For this reason, we present an experimental clinical trial performed on canines with tracheobronchomalacia, using a new atraumatic removable tracheal spiral stent (SS). Both implantation procedure and clinical improvement have been analyzed in this study.Methods: In this study, four small dogs, a mean weight of 4.89 kg and body condition scores IV‐V, were included. SS was implanted by two different surgical approaches. Image and clinical follow‐up have been performed during 90 days. Symptoms were evaluated from 1 to 10 every week. Results: This study achieved 100% technical and clinical success. Median tracheal diameters were as follows: cervical 10.85 (3.3), inlet 7.75 (2.1), and carina 7.75 (1.9) mm, and length was 77.5 (26) mm. A 12 × 10 × 100‐mm SS was implanted in all cases. Goose honk cough punctuation improved from 8 to 1; also, there were important changes in exercise intolerance, a mean weight loss of 8.76%. The values of modified Karnofsky scale varied from 50 (20) before surgery to 90 (10) after 30 days of surgery. Neither granuloma tissue nor fractures of the prosthesis was observed.Conclusion: The results in dogs are promising, and a new therapeutic alternative seems to be available for veterinarian field. The similarity of this disease between dogs and newborns suggests that this SS design can also be useful for human trials

A New Removable Helical Metallic Stent for the Treatment of Tracheomalacia in Children: Study in Pathological Animal Model

Background: Congenital tracheomalacia is a pathology with no consensus of medical or surgical approach. The permanent nature and the major complications associated with metallic stents have limited their use over the years. The purpose of this study was to evaluate the feasibility of a helical stent design removal. Methods: Ten dogs diagnosed with tracheal collapse and treated with the helical stent were involved in the study. Animals were classified into three groups depending on stent indwelling time. Prior to the removal, endoscopic evaluation was performed to assess endothelization grade, mucous accumulation, and the presence of stenosis. During the removal, bleeding, fracture, or impossibility of removal were noted. After the removal, all macroscopic mucosal changes were recorded. Results: Technical success was 100%, without any complications. Complete epithelization of the stent was visualized in 7/10 animals. The removal procedure duration ranged from 2–12 min. At post-removal endoscopy, bleeding or epithelial damage, was visualized in any case. Stent fracture during removal occurred in one animal. Conclusions: The removal of a metallic stent with spiral geometry is feasible, simple, and without complications, regardless of the degree of neo-epithelialization