According to [the expert’s] report, he did not consult any of the medical literature concerning Mersilene mesh or any of the documentation about the product. He also gave no reasons or explanation for his conclusions. It is a well established rule that without more than his credentials and subjective opinion, an expert’s testimony that a medical condition simply is so is not admissible.
[Plaintiff’s surgeon] testified that he was aware of the risks inherent in using Mersilene mesh, and stated that he was personally aware of the possibility of adverse events including extrusion and erosion. . . . [He] also testified that he read the Contraindications section of the Mersilene package insert, which advised that . . . subsequent infection may require removal of the material. [He] saw infection as a very serious potential issue and took that possibility into account in deciding whether surgery with Mersilene mesh was the best option for Smith.