Which parameters might predict complications after natural orifice endoluminal surgery (NOTES)? Results from a randomized comparison with open surgical access in pigs - Fritscher-Ravens, A; Ghanbari, A; Thompson, S; Patel, K; Kahle, E; Fritscher, T; Niemann, H; Koehler, P; Milla, P (Endoscopy, 2007)