Pseudoaneurysm and Intracardiac Fistula Caused by an Infected Paclitaxel-Eluting Coronary Stent

Abstract

A 54-year-old man with end-stage renal disease presented with chest pain. Five months before presentation the patient had a right-foot cellulitis that was treated with amoxicillin clavulanate. Two weeks later, the patient suffered an inferior wall ST-elevation myocardial infarction that required immediate percutaneous coronary intervention with paclitaxel-eluting stents (Taxus, Boston Scientific, Natick, Mass) in the proximal and mid-right coronary artery (RCA). Over the next 4 months, the patient had recurrent fevers and grew Staphylococcus aureus on repeat blood cultures. The source of infection was attributed to recurrent infected dialysis catheters. The patient had 3 catheter replacements and was treated with intravenous vancomycin and oral rifampin. On examination, the patient had a continuous murmur along the right sternal border and an elevated troponin I level of 2.45 ng/mL (normal range: 0.00 to 0.09 ng/mL).Coronary angiography revealed an occluded proximal RCA stent (asterisks in Figure 1, and Movie I, online-only Data Supplement), a large pseudoaneurysm off the stent (arrowhead in Figure 1), and a fistula into the right atrium (RA) (arrow in Figure 1). A 64-slice multidetector computed tomographic angiogram (GE Healthcare, Chalfont St. Giles, United Kingdom) confirmed both the pseudoaneurysm (arrowhead in Figures 2 and 3) and fistula into the RA (arrow in Figures 2 and 3). Transesophageal echocardiogram (Siemens, Malvern, Pa) identified serpiginous echodensities (arrowhead in Figure 4A, and Movie II, online-only Data Supplement) along the RA wall consistent with vegetation and a fistula inflow from the RCA (arrow in Figure 4B, and Movie III, online-only Data Supplement).The patient underwent a resection of the RCA stents and pseudoaneurysm, evacuation of the RA vegetation, and coronary bypass to the distal RCA with a saphenous vein graft. Microscopic specimen from the RA revealed tissue necrosis with a predominance of neutrophils consistent with an abscess ( Figure 5). The patient received intravenous nafcillin and oral rifampin for an additional 6 weeks after surgery. The patient is doing well 6 months after the operation.To date, there have been only 4 other reported cases of drug-eluting coronary stent infections. [1][2][3][4] In all cases S. aureus bacteremia was responsible for causing mycotic stent complications. Although mycotic aneurysms, pseudoaneurysms, and abscesses have been previously reported in both bare-metal and drug-eluting stent infections, this is the first reported case of an infected coronary stent that developed an intracardiac fistula. The mechanism of drug-eluting stent infection is not well understood. Potential causes for drugeluting stent infections include impairment of local immunosuppression and endothelialization caused by the paclitaxel or sirolimus released from the stent and/or bacteremia at the time of catheterization. [1][2][3][4] In fact, Ramsdale et al reported that up to 17.7% of patients who underwent complex percutaneous coronary interventions had detectable b...

Successful percutaneous treatment of a mycotic right coronary to right ventricle fistula

“…Acquired mycotic coronary fistulas are very rare, having been reported on four occasions previously [1][2][3][4] ; similar to our case, all cases occurred in the setting of staphylococcal sepsis and underlying renal impairment. These cases were, however, managed surgically with histology confirming a mycotic process.…”

Coronary Aneurysms After Drug-Eluting Stent Implantation

“…Focal infection. Some investigators have reported the exceedingly rare occurrence of mycotic CANs or coronary pseudoaneurysms after DES implantation (17)(18)(19)(20)(21). It has been suggested that local DES infection may result from direct contamination of the device at the time of delivery or from subsequent bacteremia.…”

“…The immunosuppressive activity of DES could be implicated. In most cases Staphylococcus aureus infections have been shown (17)(18)(19)(20)(21). These patients typically present with fever and systemic manifestations, including septicemia, and a clinical picture of fulminant infection with poor prognosis.…”

“…Although CAN may develop as a result of exaggerated positive remodeling of the vessel wall (13)(14)(15)(16), the underlying pathophysiology remains unknown. In some patients, this phenomenon has been linked to hypersensitivity reactions (15), bacterial arteritis (17)(18)(19)(20)(21), or other rare predisposing factors such as Kawasaki disease (14). Finally, it has also been suggested that DESrelated CAN might predispose to DES thrombosis (15,18).…”

Integrated Cardiothoracic Imaging with MDCT

“…Coronary mycotic aneurysms, pseudoaneurysms and abscesses have been previously reported in both bare-metal and drug-eluting stent infections (Jang et al 2007). However, no coronary-to-bronchial anastomoses have been described in this disease.…”