A South Dakota surgeon admitted to mistakenly removing an Iowa woman’s healthy kidney but denied that he breached the standard of care, according to the surgeon’s response to a lawsuit filed by the patient.

Dr. Scott Baker and The Surgical Institute of South Dakota acknowledged in an answer to Dena Knapp’s lawsuit that Baker removed Knapp’s right kidney instead of an adrenal gland and an associated mass, the Argus Leader reported. Knapp, of Milford, Iowa, filed the lawsuit last month alleging professional negligence.

She developed stage-three kidney disease after her October 2016 surgery.

Baker and the Sioux Falls hospital “deny the nature, scope and extent of plaintiff’s claimed injuries, losses and damages,” their response stated.

Knapp alleged that she wasn’t told about the mix-up until after she was released from the hospital. Baker had known on the day of the surgery that he hadn’t removed the adrenal gland because he was notified by Avera McKennan Hospital’s pathology department, according to the lawsuit.

But Baker denied the claim in his answer, claiming that Knapp was provided with the information on the day of her surgery.

Knapp’s medical records also indicated “a very superiorly located right adrenal gland,” which was near the large lobe of her liver, according to the defendant’s answer.

Baker and The Surgical Institute said they did not breach the standard of care by removing the kidney, failing to remove the adrenal gland and failing to admit the mistake. They also deny that Knapp suffered damages.

Knapp chose to have her adrenal gland removed at the Mayo Clinic in Rochester, Minnesota.