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Corrosion casting of the subglottis following endotracheal tube intubation injury: a pilot study in Yorkshire piglets.

Kus LH, Sklar MC, Negandhi J, Estrada M, Eskander A, Harrison RV, Campisi P, Forte V, Propst EJ - J Otolaryngol Head Neck Surg (2013)

Bottom Line: The subglottic region was evaluated using scanning electron microscopy looking for angiogenic and hypoxic or degenerative features and groups were compared using Mann-Whitney tests and Friedman's 2-way ANOVA.Amongst hypoxic/degenerative features, extravasation was the only feature that was significantly higher in the accelerated subglottic injury group (P=.000).Subglottic injury due to intubation and hypoxia may lead to decreased angiogenesis and increased blood vessel damage resulting in extravasation of fluid and a decreased propensity toward wound healing in this animal model.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Purpose: Subglottic stenosis can result from endotracheal tube injury. The mechanism by which this occurs, however, is not well understood. The purpose of this study was to examine the role of angiogenesis, hypoxia and ischemia in subglottic mucosal injury following endotracheal intubation.

Methods: Six Yorkshire piglets were randomized to either a control group (N=3, ventilated through laryngeal mask airway for corrosion casting) or accelerated subglottic injury group through intubation and induced hypoxia as per a previously described model (N=3). The vasculature of all animals was injected with liquid methyl methacrylate. After polymerization, the surrounding tissue was corroded with potassium hydroxide. The subglottic region was evaluated using scanning electron microscopy looking for angiogenic and hypoxic or degenerative features and groups were compared using Mann-Whitney tests and Friedman's 2-way ANOVA.

Results: Animals in the accelerated subglottic injury group had less overall angiogenic features (P=.002) and more overall hypoxic/degenerative features (P=.000) compared with controls. Amongst angiogenic features, there was decreased budding (P=.000) and a trend toward decreased sprouting (P=.037) in the accelerated subglottic injury group with an increase in intussusception (P=.004), possibly representing early attempts at rapid revascularization. Amongst hypoxic/degenerative features, extravasation was the only feature that was significantly higher in the accelerated subglottic injury group (P=.000).

Conclusions: Subglottic injury due to intubation and hypoxia may lead to decreased angiogenesis and increased blood vessel damage resulting in extravasation of fluid and a decreased propensity toward wound healing in this animal model.

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Related in: MedlinePlus

SEM imaging of corrosion casted control trachea. (A) External surface showing longitudinal vessels (LV) that give off circumferential branches (CB) connected by vertical branches (VB) that course deeply to form a dense capillary plexus. (B) The lumenal surface is an interconnected mesh of capillaries with vessel buds, sprouts, and intussusceptions. Hypoxic or degenerative features are not visible.
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Figure 4: SEM imaging of corrosion casted control trachea. (A) External surface showing longitudinal vessels (LV) that give off circumferential branches (CB) connected by vertical branches (VB) that course deeply to form a dense capillary plexus. (B) The lumenal surface is an interconnected mesh of capillaries with vessel buds, sprouts, and intussusceptions. Hypoxic or degenerative features are not visible.

Mentions: All 3 experimental animals survived hypoxic conditions and corrosion casting was successful in all 6 animals. Gross inspection of casts from control animals revealed the subglottic and tracheal vasculature to be cylindrical, measuring approximately 0.3 mm in thickness (Figure 2). There were two large longitudinal vessels (LV, one on each side) at the posterior aspect of the trachea near the tracheoesophageal groove (Figure 2). Regularly-spaced circumferential branches (CB) coursed between the longitudinal vessels which interdigitated with the dense vasculature of the esophagus posteriorly and anastomosed anteriorly in the midline of the trachea (Figure 2). Smaller vertical branches (VB) connected the circumferential vessels and travelled deeply to form a dense plexus of fine capillaries on the lumenal side of the specimen. SEM of the posterior surface of the trachea demonstrated this complex vascular network of longitudinal, circumferential and vertical vessels in better detail (Figure 4), which was vastly different in appearance than the vascular network on the lumenal surface that demonstrated a fairly uniform interconnected mesh of capillaries (Figure 5).


Corrosion casting of the subglottis following endotracheal tube intubation injury: a pilot study in Yorkshire piglets.

Kus LH, Sklar MC, Negandhi J, Estrada M, Eskander A, Harrison RV, Campisi P, Forte V, Propst EJ - J Otolaryngol Head Neck Surg (2013)

SEM imaging of corrosion casted control trachea. (A) External surface showing longitudinal vessels (LV) that give off circumferential branches (CB) connected by vertical branches (VB) that course deeply to form a dense capillary plexus. (B) The lumenal surface is an interconnected mesh of capillaries with vessel buds, sprouts, and intussusceptions. Hypoxic or degenerative features are not visible.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815236&req=5

Figure 4: SEM imaging of corrosion casted control trachea. (A) External surface showing longitudinal vessels (LV) that give off circumferential branches (CB) connected by vertical branches (VB) that course deeply to form a dense capillary plexus. (B) The lumenal surface is an interconnected mesh of capillaries with vessel buds, sprouts, and intussusceptions. Hypoxic or degenerative features are not visible.
Mentions: All 3 experimental animals survived hypoxic conditions and corrosion casting was successful in all 6 animals. Gross inspection of casts from control animals revealed the subglottic and tracheal vasculature to be cylindrical, measuring approximately 0.3 mm in thickness (Figure 2). There were two large longitudinal vessels (LV, one on each side) at the posterior aspect of the trachea near the tracheoesophageal groove (Figure 2). Regularly-spaced circumferential branches (CB) coursed between the longitudinal vessels which interdigitated with the dense vasculature of the esophagus posteriorly and anastomosed anteriorly in the midline of the trachea (Figure 2). Smaller vertical branches (VB) connected the circumferential vessels and travelled deeply to form a dense plexus of fine capillaries on the lumenal side of the specimen. SEM of the posterior surface of the trachea demonstrated this complex vascular network of longitudinal, circumferential and vertical vessels in better detail (Figure 4), which was vastly different in appearance than the vascular network on the lumenal surface that demonstrated a fairly uniform interconnected mesh of capillaries (Figure 5).

Bottom Line: The subglottic region was evaluated using scanning electron microscopy looking for angiogenic and hypoxic or degenerative features and groups were compared using Mann-Whitney tests and Friedman's 2-way ANOVA.Amongst hypoxic/degenerative features, extravasation was the only feature that was significantly higher in the accelerated subglottic injury group (P=.000).Subglottic injury due to intubation and hypoxia may lead to decreased angiogenesis and increased blood vessel damage resulting in extravasation of fluid and a decreased propensity toward wound healing in this animal model.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Purpose: Subglottic stenosis can result from endotracheal tube injury. The mechanism by which this occurs, however, is not well understood. The purpose of this study was to examine the role of angiogenesis, hypoxia and ischemia in subglottic mucosal injury following endotracheal intubation.

Methods: Six Yorkshire piglets were randomized to either a control group (N=3, ventilated through laryngeal mask airway for corrosion casting) or accelerated subglottic injury group through intubation and induced hypoxia as per a previously described model (N=3). The vasculature of all animals was injected with liquid methyl methacrylate. After polymerization, the surrounding tissue was corroded with potassium hydroxide. The subglottic region was evaluated using scanning electron microscopy looking for angiogenic and hypoxic or degenerative features and groups were compared using Mann-Whitney tests and Friedman's 2-way ANOVA.

Results: Animals in the accelerated subglottic injury group had less overall angiogenic features (P=.002) and more overall hypoxic/degenerative features (P=.000) compared with controls. Amongst angiogenic features, there was decreased budding (P=.000) and a trend toward decreased sprouting (P=.037) in the accelerated subglottic injury group with an increase in intussusception (P=.004), possibly representing early attempts at rapid revascularization. Amongst hypoxic/degenerative features, extravasation was the only feature that was significantly higher in the accelerated subglottic injury group (P=.000).

Conclusions: Subglottic injury due to intubation and hypoxia may lead to decreased angiogenesis and increased blood vessel damage resulting in extravasation of fluid and a decreased propensity toward wound healing in this animal model.

Show MeSH
Related in: MedlinePlus