WASHINGTON Bleeding during or after superficial cutaneous surgery may provoke more worry from both patients and their clinicians, but thrombotic events actually have greater consequences and are harder to detect, Dr. Clark C. Otley said at the annual meeting of the American Academy of Dermatology.
Bleeding "almost never causes a permanent disability," but a thrombotic complication that occurs after stopping a patient's blood thinner perioperatively "is much more serious and underappreciated because they're going to go to an ER for their stroke and you may never know about it," said Dr. Otley, who is a professor of dermatology at the Mayo Clinic, Rochester, Minn.
Based on the results of a survey of dermatologic surgeons, Dr. Otley found that 72% of them believed that they could tell if a patient was taking a blood thinner based on how the patient "oozed" intraoperatively.
In another study, however, with 110 patients undergoing cutaneous excisional surgery, Dr. Otley and his colleagues found that blinded dermatologic surgeon observers were able to determine if patients were taking a blood-thinning agent with a sensitivity of only 14% and a false-positive rate of 16% (Plast. Reconstr. Surg. 2002;110:98103).
In another blinded study of 100 patients undergoing coronary artery bypass graft who were taking a placebo or aspirin, cardiac surgeons were correct about the patients' blood thinner status only 51% of the time.
"I would argue that, objectively, you really can't tell whether somebody [is] on a blood thinner," he said.
Of 11 studies that have evaluated patient risk of hemorrhage while on blood thinners, 10 have found no increased risk of severe hemorrhagic complications.
In the one conflicting study of 21 patients, warfarin complications such as persistent bleeding, hematoma, infection, and graft loss occurred (Aesthetic Plast. Surg. 2002;26:4835).
In a member survey of the American College of Mohs Micrographic Surgery and Cutaneous Oncology, 168 surgeons reported 46 patients who had thrombotic events within a 3-day period before or after stopping a blood thinner, including three deaths.
This yielded a rate of 1 thrombotic event per 12,816 operations, or 1 of every 6,219 operations in which warfarin was discontinued and 1 of every 21,448 when aspirin was not used (J. Am. Acad. Dermatol. 2003;48:2337).
Another more recent study reported thrombotic complications in 126 patients, including 15 deaths.
"Medically necessary blood thinners should, in general, be continued if there aren't countermanding variables that indicate a need to stop them," Dr. Otley commented.