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

Abstract

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.

In Vivo Molding of Airway Stents

“…Furthermore, helical airway stents made from superelastic nitinol (NiTi) metal have previously been demonstrated to possess a number of desirable properties including resistance to migration, minimal disruption to mucus flow, and the ability to maintain patency of malacic airways while not eroding through tracheal tissue. [ 12,22,23 ] Moreover, if a helical stent becomes endothelialized, it can be removed with minimal damage to the airways using an unscrewing motion similar to how a corkscrew is removed from a cork. [ 12 ]…”

“…While the use of polymers enables the design of stents with a broad range of mechanical stiffnesses, they are also much more compliant than metals. Since helical NiTi stents have been demonstrated to provide sufficient radial support and resistance to migration while not eroding through tracheal tissue, [ 12,22,23 ] our goal was to demonstrate that we could fabricate in vivo molded stents of a comparable stiffness. We selected tubing with an inner diameter of 1.14 mm and an outer diameter of 1.57 mm.…”

State of the Science in Tracheal Stents: A Scoping Review

“…Twenty-eight studies employed bare metallic stents, grouped into four distinct types: steel, [10][11][12][13][14][15][16][17][18][19] nitinol (Ni-Ti alloy), 4,12,13,[19][20][21][22][23][24][25][26][27][28][29] magnesium alloys, [30][31][32][33] and elgiloy (Co-Cr-Ni alloy) 23,34 as outlined in portions of Tables I-III. Only two studies failed to identify the metal used in the employed tracheal stent.…”

“…Only two studies failed to identify the metal used in the employed tracheal stent. 35,36 Of the studies on bare-metal stents, eight were in humans, 4,[10][11][12][13][34][35][36] four in swine, 15,17,19,26 seven in rabbits, 14,16,25,29,[31][32][33] five in canines, [20][21][22][23][24] one in sheep, 18 one in felines, 28 and one in rats. 30 Nitinol, steel, and elgiloy stents were used in human as well as pre-clinical studies, while magnesium alloy stents were trialed only in animal models to determine feasibility and biocompatibility.…”

Wet Adhesive Hydrogels to Correct Malacic Trachea (Tracheomalacia): A Proof of Concept

“…These changes in tracheal shape are accountable for airway collapse during expiration and forceful efforts in an intrathoracic segment of the trachea. This condition prevents normal breathing and could be life-threatening, especially for newborns [1] . In neonates, infants, and small children, tracheal lumen obstruction up to 50% due to a posterior to anterior collapse (tracheal muscle movement towards the cartilage ring) can be physiological, collapse exceeding 50% obstruction will cause respiratory symptoms and collapse >75% will be critical.…”