Yes, a patient can file a malpractice suit, despite signing a consent form under at least two conditions.
For example, if a doctor does not explain all of the risks associated with the treatment to the patient. Prior to the signing the consent form, which details the risks, the doctor is responsible to make sure the patient understands the risks involved. Often, in the interest of time, the health care provider doesn’t disclose every single possible risk, instead emphasizing the common and biggest risks. Sometimes in a rushed environment that task is delegated to medical assistant who does not have all the information to adequately inform the patient. The information gets lost and the patient lacks all the correct information to make an informed decision.
If patients do not understand the risks because they were downplayed or glossed over, that is another potential malpractice scenario. Another is when a patient consents to one procedure but the doctor performs a different one. Usually this happens when a procedure for one body part is performed on another. Even if it is successful, the patient can sue for lack of informed consent. This doesn’t apply if the surgeon discovers a similar medical problem and fixes it during the initial procedure. An example of this includes a planned double bypass surgery becoming a triple bypass when the surgeon discovers additional damage during the surgery.