Shimizu M, Yoshikawa N, Yagi Y, Tsumura Y, Kukida A, Hirakawa K, Hotta A, Nakamoto A, Ohira N, Tatekawa S. Masui. 2014 Aug;63(8):841-5
Bronchoscopic view through the i-gel was graded after insertion, whereupon tracheal intubation was performed and the i-gel removed. First attempt at intubation successful in all 52 patients.
Link to abstract