There are two kinds of endotracheal tubes used for general anesthesia. One is a common tube made of plastic or silica gel, which is easy to fold. The other is a steel wire reinforced catheter, which is not easy to fold. The former is relatively cheap and enough for most general anesthesia operations; The latter is expensive, but for those operations that require inversion of posture and have special requirements for posture, this catheter has special advantages, which can ensure airway patency and intraoperative ventilation safety. Therefore, these two catheters are not good, but each has its own advantages, depending on the situation.

As for the steel pipe and stainless steel you mentioned, I have never heard of it. ...