There are some differences between elderly and young adult patients regarding the anatomy of upper airways. Elderly patients have larger upper airways than young adult patients at all pharyngeal levels as revealed by CT. Another study explained that there is a progressive descent of the larynx and epiglottis with aging, which lengthens the upper airway and possibly makes it more likely to collapse.

The aim of this study is to compare the clinical efficacy of laryngeal mask airway (LMA) in elderly patients with young adults. In this study, the investigators will measure the ease of insertion, success rate of insertion, the time of insertion, oropharyngeal leak pressure, gastric leak pressure, fiberoptic position and intraoperative complications of the classic LMA.

Inclusion Criteria:

• Patients aged 20-40 and 65-85years
• ASA status 1-2
• Undergoing minor urologic surgery or lower extremity surgery
• Undergoing general anesthesia using classic LMA

Exclusion Criteria:

• Predicted difficult airway
• Increased risk of aspiration
• Gastroesophageal reflux
• Neuromuscular disease
• Significant acute or chronic lung disease