Most blood thinners safe to resume after flap surgery: Study

Blood thinners are a common medication for much of the older adult population, prescribed to prevent blood clots that can cause adverse events like heart attack or stroke. They are often stopped prior to most surgeries because of the risk of bleeding. However, according to a new study from the University of Missouri School of Medicine, holding blood thinners for too long could jeopardize the surgery’s success.

The researchers examined the outcomes of 470 patients who underwent free flap reconstruction, a common technique in head and neck surgeries that involves transplanting tissue from one part of the body to another. Most blood thinners were not associated with increased complications.

“There’s no set standard to follow on managing blood thinners before and after surgery, and that’s because these studies just haven’t been done with modern medications,” said Patrick Tassone, one of the study authors. “Our research is a nice way to start the conversation and bridge these two viewpoints.”

Complications occurred in roughly 17% of patients overall, including those not taking blood thinners. The real risk came from stopping blood thinners too early before surgery and waiting too long to restart them afterward.

“We’re looking at two competing risks: too much clotting or too much bleeding,” said Megan Gillespie, the study’s lead author. “We found that the timing of stopping and restarting blood thinners around surgery matters. When these medications were held longer, patients experienced more complications. Our goal is to better define that sweet spot for restarting blood thinners, so patients are protected from excessive bleeding and dangerous clotting alike.”

The average wait time to resume blood thinners was five days after surgery, but this long length may not be necessary, Tassone said.

“In my personal practice, I’ve become more confident with resuming blood thinners after about 48 hours,” Tassone said. “I would not do this for patients who had a bleeding event. To be definitive about it would require more data and further research.”

Free flap reconstruction surgeries in the head and neck are complicated operations on parts of the body that have robust blood supply. Although 95% are successful, understanding how to prevent bleeding events and entering the operating room again is key.

“Setting a standard on how to manage blood thinners during the operative period will help make more surgeries a success,” Tassone said.

Reference:

M.Gillespie, D.Hood, A. K.Dwivedi, T.Galloway, and P.Tassone, “Bleeding, Clotting, and Flap Failures: Management of Blood Thinners in Head & Neck Free Flaps,” The Laryngoscope (2026): 1–12, https://doi.org/10.1002/lary.70405.