CHICAGO – Bacterial contamination of sutures is surprisingly common, and periorificial sites have a suture contamination rate of nearly 100%, according to a study of sutures collected during Mohs micrographic surgeries in 182 patients.
There’s no direct correlation between suture contamination and surgery site infection, said Dr. Jeremy Sunseri of Brown University, Providence, R.I., who presented the unpublished study at the annual meeting of the American Society of Dermatologic Surgery. However, knowing the risk factors for suture contamination can help reduce the risk of infections and potential antibiotic overuse, he noted.
"For instance, the use of antibiotic-coated sutures in high-risk contamination sites, or variations on draping techniques in these areas, may prove beneficial," Dr. Sunseri noted.
The investigators removed 338 sutures directly from their sterile surgery sites, and placed them in Petri dishes with a growth medium used for the isolation of gram-positive organisms.
They further classified the sutures based on anatomic locations (17), type of surgical closure (5), and suture type (7).
More than 57% of all sutures had bacterial growth, and almost all of those collected from the nose, mouth/lip, eye/orbit were contaminated.
Sutures collected from the scalp, neck, trunk, and upper and lower extremities had significantly lower risk of contamination, ranging from 0% to 20%, with the exception of the groin, which showed a 100% contamination rate.
Sutures from flap repairs were the most frequently contaminated (71%). Sutures collected from complex closures also had a relatively high rate of contamination (68%).
Sutures from intermediate repairs had a contamination rate of 47%, while grafts, purse string closures, and incomplete closures had a 44% rate.
Staphylococci were the most commonly identified bacteria, notably isolates of of Propionibacterium acnes, Corynebacterium sp., and Rothia dentocariosa.
There were no significant differences in the contamination rates of the seven different types of sutures studied.
"The take-home message is that the suture is long and patients are dirty, so be careful where you put that suture," Dr. Sunseri said during his presentation.
Dr. Sunseri had no financial conflicts to disclose.
On Twitter @NaseemSMiller