Rare but devastating infection: Graft Infections of Thoracic Aortic Repair Grafts

Authors:
Alexander Harper, Henry Kwon, Loay Kabbani, Milosh Djuric, Sana Soman

Body of Abstract:
Open and endovascular stent graft treatment for thoracic aortopathy has increased in the past decade. Thoracic endovascular aortic repair (TEVAR) has become a treatment modality for patients who may not have tolerated an open procedure and has increased in the past decade. A rare but devastating complication from grafts is infection of graft material.  Principals in treating this disease has been gleamed from infections of abdominal aortic aneurysm repairs or aortoiliac occlusive disease.

At a single institution tertiary referral center from January 2015 to November 2024, all patients treated for their initial event of an infection or inflammatory reaction due to vascular graft or implants were evaluated. Devices or grafts that were not endovascular stent grafts or grafts used for open repair of thoracic or abdominal aorta were excluded. The sample size and incidence of disease precluded any meaningful statistical comparisons.

In total, 41 patients were treated for an infection of an aortic graft: 2 for grafts in the ascending aorta and arch, one for a TEVAR graft, 1 for thoracoabdominal grafts, 16 patients for abdominal aortic grafts, and 15 with aortoiliac grafts.  The incidence of graft infection is low but those who did  have a graft infection, the mortality rate for grafts placed in the arch, TEVAR, and thoracoabdominal grafts were 100%. Grafts placed distal to the diaphragm mortality rates were 25% for abdominal aortic grafts and 6.7% for aortoiliac graft infections.

Infections of thoracic grafts were from gram positive species including staphylococcus aureus, methicillin resistant staphylococcus aureus (MRSA), and streptococcus pneumoniae. Inciting incidents included dental procedures, septic arthritis, and a fistula between the bronchus and aorta. Two patients underwent replacement of the grafts while two had no viable surgical options for replacing the infected graft. Mortalities associated with abdominal aortic graft infections had cultures that were positive for staphylococcus aureus, candida, enteric micro-organisms, and one expired prior to cultures were obtained. Those who survived underwent surgery for replacement of their graft with cultures often consistent with enteric organisms.  Aortoiliac grafts infections had a wide variety of organisms. Those who survived were often sent home on a 6-week course of antibiotics and required transfer to a subacute skilled nursing facility.

Although rare, infections of graft material of the thoracic aorta carry significant mortality with little opportunity for operative intervention in comparison to those with abdominal aortic graft infections and distal graft infections. Medical and surgical management is limited, and significant care should be taken in prevention of infections of these grafts.