An alternative model for prediction of transplant-free survival in patients with implantation of transjugular intrahepatic portosystemic shunt (TIPS): The Freiburg risk score - Bettinger, D; Sturm, L; Pfaff, L; Giesler, M; Schmidt, A; Boettler, T; Weiss, KH; Heinzow, H; Thimme, R; Schultheiss, M (Zeitschrift für Gastroenterologie, 2019)