Breast cancer patients who had reconstructive surgery using implants immediately after they had mastectomies were twice as likely to acquire infections as women who immediately had breast reconstruction using their own tissue, a study published on Monday said.

The two-year study found that 5.3 percent or 50 of nearly 950 patients, who had mastectomies or beast reconstructions procedures at Washington University-affiliated hospitals between 1999 and 2002, developed infections within a year of their procedures, either inside of outside the hospital. The infections happened at an average of 47 days following the surgery.

“The surgical site infection rates following breast surgery seem to be much greater than the nationally reported incidence of 2 percent and much higher than what is expected for clean surgical procedure,” Margaret A. Olsen of the Washington University School of Medicine in St. Louis wrote in her report, according to Reuters.

The authors explain that reported infections at surgical sites following mastectomies and other breast procedures range from 1 percent to 28 percent.

Physical and mental damages were not the only damages the patients undergoing this kind of surgery suffered. The study authors said the cost of the follow-up medical care is roughly 4,000 U.S. dollars per patient. Costs were taken from the hospital accounting database and included those from the original admission to the hospital for surgery as well as any readmissions within one year of surgery.

“Patients with surgical site infections had significantly higher hospital costs associated with surgery and during the one-year period after surgery compared with uninfected patients, and they had a significantly longer total length of hospital stay,” authors wrote in the study.

Olsen also urged doctors to respect specific rules before doing this kind of surgery in order to prevent infections. She recommended administering preventive antibiotics in a correct way before surgery, maintaining meticulous hand hygiene and ensuring timely removal of wound drains.

The study, supported by an Epicenter Prevention Program Cooperative Agreement for the Centers for Disease Control and Prevention was published in this month’s issue of the Archives of Surgery.