CHICAGO - Some patients painstakingly vet their surgeons to find a highly skilled professional to perform their operation, only to discover later they didn't get the person they wanted or expected.

A different physician can step in for legitimate reasons, such as a medical emergency involving the surgeon. And at academic medical centers, residents and other junior health professionals often perform procedures under supervision. Medical experts and patient advocates agree that is acceptable as long as patients are informed and give consent.

But in some cases, there can be an actual bait-and-switch, when a prominent surgeon promises to carry out the procedure but does not.

It's not clear how often such "ghost surgeries" occur, because they are not tracked or studied. But lawsuits provide a glimpse of unhappy patients who had bad outcomes, started to look into what went wrong, and learned they were mistaken on which doctor did the procedure.

Denyse Richter, of New Hampshire filed a medical malpractice case after her heart was severely damaged in a cardiac operation. She had sought out a renowned, triple board-certified cardiologist, but instead the procedure was performed by a less experienced provider. Now Richter requires a pacemaker.

"I sought the rock star, and I got the opening act," said Richter, whose case went to a jury in 2008 before being settled for an undisclosed amount.

Patient advocates say it's not uncommon to hear from people with similar stories, although such cases can be difficult to win in court.

"We can go into the operating room, be sedated and have a different person we know nothing about cut into our bodies," said Dr. Julia Hallisy, a dentist who is president of The Empowered Patient Coalition, based in San Francisco. "It's alarming and disconcerting on so many levels, not just from a medical or legal standpoint, but from a trust and ethical standpoint."

Hallisy got interested in ghost surgery in 1998, when a review of her late daughter's medical records revealed the name of the surgeon she had expected to perform a biopsy wasn't in the operative notes. Listed instead were two medical residents, Hallisy said.

The surgeon had appeared after the procedure - dressed in scrubs and holding a vial containing a piece of her daughter's bone - to say it went well, Hallisy said.

It "seemed intentionally misleading," she said. The family felt manipulated and filed a complaint with the California medical board. Hallisy said the experience motivated her to start an advocacy group.

The American College of Surgeons tells its members it's unethical to mislead a patient about the identity of the person performing an operation.

"This principle applies to the surgeon who performs the operation when the patient believes that another physician is operating and to the surgeon who delegates a procedure to another surgeon without the knowledge and consent of the patient," the guidelines state.

Those guidelines also make clear the surgeon is responsible for the patient's welfare throughout the operation, including remaining in the operating room.

Dr. Joanne Conroy, chief health care officer for the Association of American Medical Colleges, representing the nation's medical schools and teaching hospitals, said informed consent has greatly improved.

"Over the last 30 years, we have become much more explicit about the fact that students will be involved in your care," she said. "We have been much more granular about talking about their involvement and talking to patients about their presence."

But even patients who shop around for a surgeon may not take the time to understand what exactly will happen in the operating room. At least one study reported most people don't read their consent form, which spells out who will be involved in critical parts of the procedure.

As stark as some situations may seem, experts say a gray area exists where misunderstandings between patients and providers can occur. Advocates advise patients to review their surgical consent form early enough to ask questions about who will be involved with the procedure and to discuss any concerns with their surgeons.

"A true informed consent process begins with a transparent sharing of information," said Patty Skolnik, executive director of Citizens for Patient Safety, "and that has to be an effective and open communication between the patient and the health professional."

In the case involving Northwestern urologist Dr. Robert Nadler, Mary Ann Bart, of Springfield, Ill., said she made sure her consent form reflected her wishes by writing that "consent is for Dr. Nadler to perform procedure himself."

But according to Bart's lawsuit, the doctor never scrubbed in for the procedure to remove her recurrent kidney stones, despite a verbal promise and Nadler's signature on the form. Instead, she alleges, one of his urology fellows did the operation.

Complications from the surgery required Bart to be resuscitated twice, and she has suffered medical and emotional problems that may not have happened had Nadler overseen her care during and after the operation, her lawsuit charges.

"There's no part of my mind or body that was not affected by this," Bart said.

Neither Nadler nor the urology fellow named in the suit, Dr. David Rebuck, responded to requests for an interview, and Northwestern declined to comment on the lawsuit, citing pending litigation.

"We are an academic medical center where it's part of our mission to teach, develop and employ the very best physicians, nurses and health specialists," a statement from the hospital said. "It's this aspect of our health system - the fact that we're a teaching hospital - that speaks to how and why we are among the nation's most advanced and among patients' most preferred hospitals."

The statement said "generally speaking, surgical consent forms allow for supervision and assistance from multiple staff members. This differs significantly from 'informed consent,' which can't be generalized, as it signifies a patient-physician conversation, and every physician has a different approach."

In Richter's case, she had opted to have a heart procedure so she could stop taking the medication that had kept her lifelong arrhythmia under control. Richter, 39 at the time, wanted to have a baby.

She said Dr. Laurence Epstein, chief of the cardiac arrhythmia service at Brigham and Women's Hospital in Boston, had agreed to handle her operation himself. But he booked a conflicting appointment days earlier and, instead of notifying her or rescheduling, asked an associate to step in without telling her.

The physicians' attorney, Philip E. Murray Jr., said the associate was well-qualified, and the doctors did not try to carry out a bait-and-switch. When Epstein realized he was running late, he called the hospital to instruct the associate, Dr. Kyoko Soejima, to offer Richter a choice between waiting for Richter or allowing Soejima to do the procedure, Murray said.

Richter then gave the OK to proceed without Epstein, Murray said. Richter said she does not recall discussing the matter with Soejima and said she would not have agreed to go ahead without Epstein.

"I was devastated," Richter said. "The outcome didn't need to happen, because if I had had the surgery I needed done, by the surgeon I contracted with, it probably wouldn't have happened. I was dumbfounded that they could do something like this without your knowledge."

What to consider before your surgery

Most operations are planned, which gives patients the opportunity to ask questions and deal with consent issues. Although consent forms differ depending on the institution, they should include the name of the doctor performing the operation and the procedure you're authorizing. It might also ask permission to administer anesthesia and attend to unforeseen problems discovered during surgery.

A teaching facility might ask for approval for other things as well, such as use of photographic or other nonmedical equipment and the presence of observers. Some hospitals and doctors will hand you a consent form early on; others will offer it closer to surgery, maybe even the same day.

•If you have concerns about who will be providing your surgical care, experts suggest you:

•Request the surgical consent form in advance of your operation and give yourself enough time to read it.

•Consider who will perform all aspects of your procedure, including the anesthesia.

•Educate yourself about the facility's and surgeon's policies on teaching and supervising students and trainees.

•Ask if the surgeon is going to perform the entire operation.

•Find out if the surgeon will be present the entire time, and if not, how long he might be gone and who will be in charge during his absence.

•Cross out parts of the consent form you are not in agreement with and write down your expectations, initialing the changes, but discuss it with your surgeon first. Don't wait until the last minute.

•Realize if your surgeon disagrees with you, he could cancel your operation and you might have to find another doctor. You, too, can call off your operation.

•Make sure your surgeon is named on the consent form; don't sign a blank form.

•Inquire about the policy for informing patients about changes in who will perform parts, or all, of your operation.

Remember informed consent involves more than just filling out a form. It involves communication and transparency. Try to be respectful and nonconfrontational throughout this process.