The first guide to diagnose, treat and prevent infections of blood vessels, grafts and endovascular devices was issued Thursday by the American Heart Association.

Infections can occur after procedures to open clogged arteries or to place devices that prevent aneurysms from rupturing, said vascular surgeon John Eidt, M.D., vice chair for faculty development in the department of surgery at Baylor University Medical Center in Dallas, who was not involved in writing the new scientific statement.

People with peripheral artery disease or an abdominal aortic aneurysm may require a graft or stent-graft. PAD typically causes narrowing of the leg arteries, resulting in pain and difficulty walking. If left untreated, PAD can lead to gangrene and amputation of a limb. An abdominal aortic aneurysm enlarges the aorta, the large blood vessel supplying blood to the abdomen, pelvis and legs.

Vascular surgeons reroute — or bypass — blood flow around a clogged vessel by attaching a healthy artery or vein from the patient or a cadaver, or a fabric blood vessel. The new vessel is called a vascular graft. In other cases, surgeons cut out the diseased part of the vessel and sew in the vascular graft.

Other procedures use an endovascular stent-graft to reinforce blood vessels with weak spots, or aneurysms, using fabric-covered metal scaffolding delivered through a catheter. The stent-graft helps prevent an aneurysm from rupturing.

The infections addressed by the statement are “life-threatening or limb-threatening,” said Walter R. Wilson, M.D., chair of the statement writing group and an infectious disease specialist at the Mayo Clinic in Rochester, Minnesota. “We’re trying to bring an awareness to clinicians: They need to think of these infections that may not be on their checklist.”

Eidt, a Society for Vascular Surgery volunteer, said the new statement provides a “framework” for preventing, diagnosing and treating a wide variety of vascular infections.

“No institution, to my knowledge, has zero infections,” said Eidt. “We’re like cobblers trying to make a good pair of shoes, one patient at a time. How you make the diagnosis and what treatment plan you come up with is very surgeon- and institution-driven.”

Vascular graft infections and aneurysms occur in many parts of the body, according to the statement. They can occur in the groin, abdomen, chest or legs. Infection rates range from 1 percent to 6 percent depending on where the graft is located in the body.

Infections can occur months to years after vascular procedures. Symptoms range from fever, chills, elevated white blood cells and signs of bloodstream infection to painful swelling, draining wounds and pain.

Mycotic, or infectious aneurysms, another type of infection addressed by the statement, occur in up to 5 percent of patients. Such infections cause few symptoms and often go undiagnosed until autopsy.

“Certain tests can be used to detect mycotic aneurysm, but if we don’t know what tests to do, we can miss the diagnosis and patients may have a sudden, possibly fatal rupture,” Wilson said.

An infectious aneurysm can result from infections in other parts of the body, blood vessel trauma from catheterization, traumatic injury or intravenous drug use.

People who are most likely to require vascular surgery and develop infections are overweight or obese, have diabetes, high blood pressure or smoke, the statement said.

“It seems like our standard patient has multiple health problems,” Eidt said.

Most bacteria causing infections are already in the patient’s body, he said. Having multiple procedures “dramatically increases the risk of surgical graft infections.”

The statement recommends antibiotics for patients before vascular graft surgery. Antibiotics should also be considered for patients receiving an endovascular device, according to the statement.

Vascular surgeons should lead infection treatment, Eidt said. “The vascular surgeon is the general contractor and the prime decision-maker, and we call in others to help with other pieces of the puzzle depending on what organs are affected.”

However, many patients do not receive ongoing health care from a vascular surgeon after a procedure. They therefore need to tell their primary care doctor that they have a graft, even it if was placed years ago, Wilson said.

“Months to even years later, people who have undergone an abdominal aneurysm repair can develop a fever of unknown origin with bacteria in the bloodstream. In looking for the cause, it may not come up that five years ago they underwent a repair of an abdominal aneurysm,” Wilson said.

Paying closer attention to patients can alert doctors to the risk of infection, he said.

“If doctors let patients talk, and really listen without interrupting, they’ll tell you what’s wrong.”