Laryngopharyngeal mucosal injury after prolonged use of the ProSealTM LMA in a porcine model: A pilot study

Abstract

Purpose:Little is known about the potential for the cuff of the ProSeal™ laryngeal mask airway (PLMA) to cause laryngopharyngeal mucosal injury. The aim of this study was to investigate the effects of prolonged exposure of the laryngopharyngeal mucosa to the PLMA in an animal model. Methods:The PLMA was used for positive pressure ventilation in eight German country pigs randomized to receive different durations of anesthesia lasting three to 24 hr. Two additional pigs served as controls. Biopsies from 14 predetermined areas of the laryngopharyngeal mucosa were examined histopathologically using light microscopy. The number of areas with signs of mucosal damage was evaluated, and the degree of tissue damage was analyzed using a semiquantitative scoring system. Results:The number of areas with moderate to severe mucosal damage was 0-2 in animals anesthetized for less than 12 hr, 6 in animals anesthetized for 12-18 hr, and 12 in animals anesthetized for more than 18 hr. The severity of mucosal damage was also time-dependent, indicated by raising semiquantitative scores for epithelial and subepithelial mucosal damage. Conclusion:The histopathological findings of this study show that prolonged use of the PLMA in the pig for up to nine hours is associated with no, or only mild alterations in the laryngopharyngeal mucosa, whereas use for 12 hr or more is associated with clear signs of mucosal injury.

Prolonged use of the LMA Supreme™

“…4 In a pilot study in a porcine model, the authors concluded that only mild alterations in the laryngopharyngeal mucosa were seen with the LMA Proseal TM when used for up to nine hours, whereas mucosal injury occurs with more than 12 hr of use. 5 Given the lengthy duration of this case using an LMA Supreme during elective surgery, we conclude that the LMA Supreme could be useful for prolonged surgery, especially if tracheal intubation should be avoided. Nevertheless, further investigations are needed.…”

Prolonged Use of the Laryngeal Mask Airway ProSealTM: A Report of Seven Cases Lasting 5-11 h

“…The only disadvantages the LMA ProSeal TM has over the LMA Classic TM for prolonged use is that the airway tube has a narrower bore, making it less suitable for prolonged spontaneous breathing anaesthesia and less useful as an airway intubator. A histopathological study in German country pigs showed that the prolonged use of the LMA ProSeal TM for up to 9 h is associated with no or only mild mucosal ischemic injuries [30].…”

Nitrous oxide. Should it still be used in pediatric medicine ? (Part 1)

“…However, even tracheal rupture has been reported in two patients [44]. Damage from cuff expansion of laryngeal mask devices has also been published [45,46,47,48,49]. The diffusion is larger in silicone based tubes and laryngeal mask airways than in PVC based tubes and LMA's.…”