TULSA, Okla. (AP) — A 15th medical negligence complaint has been filed against an Oklahoma City surgeon who made international headlines after performing a risky operation in 2006 that left a Russian teen brain dead.

Plaintiff Linda K. Martin filed the civil complaint against surgeon Paul Christopher Francel in Oklahoma County District Court last Wednesday.

Meanwhile, as many as 11 of the cases against Francel could go to mediation this month.

Martin's attorney, Marissa Osenbaugh, did not discuss the specifics of the complaint Monday, but said, "any time a doctor has that many claims in that short amount of time, it obviously raises some questions."

David McPhail, an attorney for Francel, said Monday he was undecided whether he would represent Francel in the Martin case. He has previously said that he has ordered his client not to discuss any of the other cases.

Along with the negligence complaints, Francel is a defendant in a wrongful death complaint brought by Sabit Kurbanov, the father of the 16-year-old Russian boy Francel operated on.

Francel has already agreed not to practice medicine while under investigation by state medical officials, and the Oklahoma Board of Medical Licensure and Supervision will not say if the investigation stems from the Russian boy's death or other matters. The probe could take several months.

Francel attracted international attention in 2006 after agreeing to perform a free — and risky — operation on David Kurbanov, who came to St. Anthony Hospital in Oklahoma City to have a lifesaving procedure.