Multicentered analysis of percutaneous sclerotherapies in venous malformations of the face oleh Vanessa F. Schmidt, Max Masthoff, Constantin Goldann, Richard Brill, Peter B. Sporns, Peter B. Sporns, Laura Segger, Victor Schulze-Zachau, Martin Takes, Michael Köhler, Sinan Deniz, Osman Öcal, Nabeel Mansour, Muzaffer Reha Ümütlü, Mwivano Dunstan Shemwetta, Balowa Musa Baraka, Eric M. Mbuguje, Azza A. Naif, Ofonime Ukweh, Ofonime Ukweh, Max Seidensticker, Jens Ricke, Bernhard Gebauer, Walter A. Wohlgemuth, Moritz Wildgruber