Taking blood thinners before minor procedures safe for stroke patients

Many patients who have experienced strokes or mini strokes take blood thinners such as aspirin or warfarin (Coumadin) to reduce the risk of blood clots that can cause strokes.

This can pose a dilemma when a patient needs to undergo a surgical procedure, because blood thinners can increase the risk of bleeding. But a new guideline from the American Academy of Neurology advises that it is likely safe to continue taking blood thinners before minor procedures such as dental procedures, cataract surgery or dermatologic procedures. The guideline is published in Neurology, the official scientific journal of the American Academy of Neurology.

"This guideline is expected to be useful to neurologists, primary care physicians, surgeons, dentists and other healthcare providers caring for these patients," said Dr. Jose Biller, chair of the Department of Neurology of Loyola University Medical Center. Dr. Biller is one of nine co-authors of the guideline; three other authors also have Loyola ties.

The physicians evaluated evidence from 133 studies. Among their findings:

• There's a high likelihood that taking aspirin or warfarin before dental procedures will not increase the bleeding risk.
• Aspirin is likely to not increase bleeding risk before such procedures as cataract surgery, dermatologic procedures, prostate biopsy and carpal tunnel syndrome surgery. Similarly, warfarin likely will not increase the bleeding risk in dermatologic procedures and invasive ocular anesthesia.
• Aspirin possibly does not increase bleeding risk for such procedures as retinal surgery and ultrasound-guided biopsy.
• Aspirin is likely to increase the bleeding risk in orthopaedic hip procedures.

The authors provide three hypothetical examples of how the guideline could be applied:

• A 65-year-old man who had a stroke one year ago is due for routine colonoscopy screening. Given that the patient may not need to have a polyp removed during the colonoscopy -- and there's only a 2 percent chance of bleeding even if a polyp is removed -- his neurologist recommends he continue taking aspirin.
• A 70-year-old breast cancer patient who had a previous stroke is undergoing a mastectomy. There is little research on the bleeding risk of taking aspirin before such invasive procedures. So to be safe, the neurologist and patient decide to discontinue aspirin seven days before surgery, and restart it the day after surgery.
• A 60-year-old man who's had a stroke is undergoing cataract surgery. The neurologist reviews the guideline and finds the risks associated with warfarin during ophthalmologic procedures have not been established with sufficient precision. Nevertheless, the patient would rather face the risk of increased bleeding than risk another stroke. So the ophthalmologist, neurologist and patient decide to continue warfarin during the cataract surgery.