The mechanical characteristics and performance evaluation of a newly developed silicone airway stent (GINA stent)
GINA stent, a radiopaque silicone airway stent that was recently developed by the authors, was designed to minimize migration, mucostasis, and granulation tissue formation. The mechanical tests performed in the current study confirmed that the GINA stent has a lower possibility of migration and granulation tissue formation, compared to the Dumon stent. Moreover, the results of the performance evaluation using porcine models suggest that the performance of the GINA stent is not inferior to that of the Dumon stent.
The conditions regarding an ideal airway stent are cost-effectiveness, ease of insertion and removal, devoid of migration or granulation tissue formation, not excessive but adequate expansion force against airway stenosis, adequate flexibility to preserve the airway physiology, and without any impairment of the mucociliary clearance7. However, no stent is capable of fulfilling all of the aforementioned conditions; if one characteristic is superior, another tends to be inferior. For instance, if the stent has low expansion force and the likelihood of granulation tissue formation is reduced, the airway fixation of the stent declines, thereby increasing the risk of stent migration. Accordingly, metal stents have a low migration rate, but a high rate of granulation tissue formation, whereas silicone stents have a high migration rate, but a low rate of granulation tissue formation1. In terms of the inhibition of mucostasis in the stent, it is desirable to maintain the mucociliary clearance, and necessary to be flexible so that the stent inner diameter is sufficiently reduced during exhalation. The uncovered metal stent could best preserve the mucociliary clearance. However, removal of the stent is difficult, owing to epithelialization, in addition to the problem of tissue ingrowth within the stent. Consequently, an uncovered metal stent is not recommended for the management of benign airway stenosis; the use is restricted to the palliation of malignant airway stenosis, but tumor ingrowth should be a concern8. After all, improving the flexibility of the stent (enabling the reduction of stent cross-sectional area) is the most rational method of resolving mucostasis, thereby facilitating the removal of airway secretions through the enhanced expiratory flow.
In the present study, the GINA stent showed a lower expansion force and higher flexibility, compared to the Dumon stent. Although the current study did not observe any substantial difference between the two types of stents with regard to the formation of granulation tissue in the porcine models, it could be attributed to the short observation period. Granulation tissue formation is a common complication of silicone airway stents, although less than in metal stents1,4,9. Excessive expansion force and low flexibility are the predisposing factors associated with granulation tissue formation9,10,11,12. The low expansion force and high flexibility of the GINA stent implies that less force is required to expand and bend the stent, resulting in less pressure on the airway, leading to diminished mucosal inflammation and granulation tissue formation.
Despite the low expansion force, the GINA stent displayed a higher anti-migration force, compared to the Dumon stent, which was further confirmed by the animal experiments. The aforesaid superiority can be attributed to the creative surface design of the GINA stent, which comprises a right-angled triangle-shaped outer ring pertaining to the cartilaginous trachea and a raised, three-line a
GINA stent, a radiopaque silicone airway stent that was recently developed by the authors, was designed to minimize migration, mucostasis, and granulation tissue formation. The mechanical tests performed in the current study confirmed that the GINA stent has a lower possibility of migration and granulation tissue formation, compared to the Dumon stent. Moreover, the results of the performance evaluation using porcine models suggest that the performance of the GINA stent is not inferior to that of the Dumon stent.
The conditions regarding an ideal airway stent are cost-effectiveness, ease of insertion and removal, devoid of migration or granulation tissue formation, not excessive but adequate expansion force against airway stenosis, adequate flexibility to preserve the airway physiology, and without any impairment of the mucociliary clearance7. However, no stent is capable of fulfilling all of the aforementioned conditions; if one characteristic is superior, another tends to be inferior. For instance, if the stent has low expansion force and the likelihood of granulation tissue formation is reduced, the airway fixation of the stent declines, thereby increasing the risk of stent migration. Accordingly, metal stents have a low migration rate, but a high rate of granulation tissue formation, whereas silicone stents have a high migration rate, but a low rate of granulation tissue formation1. In terms of the inhibition of mucostasis in the stent, it is desirable to maintain the mucociliary clearance, and necessary to be flexible so that the stent inner diameter is sufficiently reduced during exhalation. The uncovered metal stent could best preserve the mucociliary clearance. However, removal of the stent is difficult, owing to epithelialization, in addition to the problem of tissue ingrowth within the stent. Consequently, an uncovered metal stent is not recommended for the management of benign airway stenosis; the use is restricted to the palliation of malignant airway stenosis, but tumor ingrowth should be a concern8. After all, improving the flexibility of the stent (enabling the reduction of stent cross-sectional area) is the most rational method of resolving mucostasis, thereby facilitating the removal of airway secretions through the enhanced expiratory flow.
In the present study, the GINA stent showed a lower expansion force and higher flexibility, compared to the Dumon stent. Although the current study did not observe any substantial difference between the two types of stents with regard to the formation of granulation tissue in the porcine models, it could be attributed to the short observation period. Granulation tissue formation is a common complication of silicone airway stents, although less than in metal stents1,4,9. Excessive expansion force and low flexibility are the predisposing factors associated with granulation tissue formation9,10,11,12. The low expansion force and high flexibility of the GINA stent implies that less force is required to expand and bend the stent, resulting in less pressure on the airway, leading to diminished mucosal inflammation and granulation tissue formation.
Despite the low expansion force, the
GINA stent, a radiopaque silicone airway stent that was recently developed by the authors, was designed to minimize migration, mucostasis, and granulation tissue formation. The mechanical tests performed in the current study confirmed that the GINA stent has a lower possibility of migration and granulation tissue formation, compared to the Dumon stent. Moreover, the results of the performance evaluation using porcine models suggest that the performance of the GINA stent is not inferior to that of the Dumon stent.
The conditions regarding an ideal airway stent are cost-effectiveness, ease of insertion and removal, devoid of migration or granulation tissue formation, not excessive but adequate expansion force against airway stenosis, adequate flexibility to preserve the airway physiology, and without any impairment of the mucociliary clearance7. However, no stent is capable of fulfilling all of the aforementioned conditions; if one characteristic is superior, another tends to be inferior. For instance, if the stent has low expansion force and the likelihood of granulation tissue formation is reduced, the airway fixation of the stent declines, thereby increasing the risk of stent migration. Accordingly, metal stents have a low migration rate, but a high rate of granulation tissue formation, whereas silicone stents have a high migration rate, but a low rate of granulation tissue formation1. In terms of the inhibition of mucostasis in the stent, it is desirable to maintain the mucociliary clearance, and necessary to be flexible so that the stent inner diameter is sufficiently reduced during exhalation. The uncovered metal stent could best preserve the mucociliary clearance. However, removal of the stent is difficult, owing to epithelialization, in addition to the problem of tissue ingrowth within the stent. Consequently, an uncovered metal stent is not recommended for the management of benign airway stenosis; the use is restricted to the palliation of malignant airway stenosis, but tumor ingrowth should be a concern8. After all, improving the flexibility of the stent (enabling the reduction of stent cross-sectional area) is the most rational method of resolving mucostasis, thereby facilitating the removal of airway secretions through the enhanced expiratory flow.
In the present study, the GINA stent showed a lower expansion force and higher flexibility, compared to the Dumon stent. Although the current study did not observe any substantial difference between the two types of stents with regard to the formation of granulation tissue in the porcine models, it could be attributed to the short observation period. Granulation tissue formation is a common complication of silicone airway stents, although less than in metal stents1,4,9. Excessive expansion force and low flexibility are the predisposing factors associated with granulation tissue formation9,10,11,12. The low expansion force and high flexibility of the GINA stent implies that less force is required to expand and bend the stent, resulting in less pressure on the airway, leading to diminished mucosal inflammation and granulation tissue formation.
Despite the low expansion force, the GINA stent displayed a higher anti-migration force, compared to the Dumon stent, which was further confirmed by t
GINA stent, a radiopaque silicone airway stent that was recently developed by the authors, was designed to minimize migration, mucostasis, and granulation tissue formation. The mechanical tests performed in the current study confirmed that the GINA stent has a lower possibility of migration and granulation tissue formation, compared to the Dumon stent. Moreover, the results of the performance evaluation using porcine models suggest that the performance of the GINA stent is not inferior to that of the Dumon stent.
The conditions regarding an ideal airway stent are cost-effectiveness, ease of insertion and removal, devoid of migration or granulation tissue formation, not excessive but adequate expansion force against airway stenosis, adequate flexibility to preserve the airway physiology, and without any impairment of the mucociliary clearance7. However, no stent is capable of fulfilling all of the aforementioned conditions; if one characteristic is superior, another tends to be inferior. For instance, if the stent has low expansion force and the likelihood of granulation tissue formation is reduced, the airway fixation of the stent declines, thereby increasing the risk of stent migration. Accordingly, metal stents have a low migration rate, but a high rate of granulation tissue formation, whereas silicone stents have a high migration rate, but a low rate of granulation tissue formation1. In terms of the inhibition of mucostasis in the stent, it is desirable to maintain the mucociliary clearance, and necessary to be flexible so that the stent inner diameter is sufficiently reduced during exhalation. The uncovered metal stent could best preserve the mucociliary clearance. However, removal of the stent is difficult, owing to epithelialization, in addition to the problem of tissue ingrowth within the stent. Consequently, an uncovered metal stent is not recommended for the management of benign airway stenosis; the use is restricted to the palliation of malignant airway stenosis, but tumor ingrowth should be a concern8. After all, improving the flexibility of the stent (enabling the reduction of stent cross-sectional area) is the most rational method of resolving mucostasis, thereby facilitating the removal of airway secretions through the enhanced expiratory flow.
In the present stud