RALEIGH, N.C., June 22 (UPI) -- The Duke University Health System says tests show hydraulic fluid it mistakenly used instead of detergent in sterilizing surgical tools did no harm.
A letter from Duke Health Raleigh Hospital said officials "sincerely regret any concerns you may have experienced following your care."
Meanwhile, lawyers have subpoenaed the system, demanding the test results.
Nearly 4,000 patients were operated on using the tools, WRAL Raleigh, N.C., reported Wednesday. Attorney David Stradley said he asked Duke Health in February, shortly after news of the mistake surfaced, for a sample of the fluid.
The subpoena also requests independent tests be carried out on the fluid, used during November and December at two Duke-affiliated hospitals.
Duke Health has filed legal paperwork asking that some information be allowed to remain confidential.
