Successful outcome after massive bleeding in a heart transplant recipient with mycotic aortitis. Case report

Pseudoaneurysm of the ascending aorta: case report of a donor-derived Pseudomonas infection in a heart transplant recipient

Background

Mycotic aortic pseudoaneurysm is a rare complication after heart transplantation (HTX) with remarkable mortality. Intrathoracic infection is a well-documented predisposing factor for this disease. Staphylococcus aureus, Pseudomonas aeruginosa or Candida species are commonly isolated from resected specimens of the pseudoaneurysms. We demonstrate a unique case of mycotic pseudoaneurysm caused by presumably donor-derived Pseudomonas infection in a heart transplant recipient.

Case presentation

Our 67-year-old male patient treated with diabetes mellitus underwent HTX. The donor suffered from epiglottic abscess and pneumonia with known microorganisms including Pseudomonas, therefore both the donor and recipient received targeted antimicrobial therapy and prophylaxis. Five months after the uneventful HTX, lab test of the asymptomatic patient showed moderate, increasing C-reactive protein level without obviuos source of infection. Chest computed tomography showed a large (90 mm) saccular dilatation of the tubular portion of ascending aorta. Urgent surgical intervention identified a pseudoaneurysm, histological examinations and cultures of the resected aorta verified Pseudomonas aeruginosa aortitis, while all blood cultures remained negative. Retrospective interrogation of other transplanted organs of the donor supported donor-derived infection as the transport fluid of the right kidney grew Pseudomonas. The patient received 3 weeks of ceftazidime followed by 7 months of oral ciprofloxacin therapy. One year after the operation the patient was asymptomatic with normal inflammatory markers.

Conclusions

Donor-derived infection is a rare but potential cause of aortitis. Early diagnosis, surgical intervention and adjuvant antibiotic therapy seem to be the keys to successful management of mycotic pseudoaneurysms after HTX.

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

Clinical significance of donor-unrecognized bacteremia in the outcome of solid-organ transplant recipients

We evaluated the clinical significance of unrecognized bacteremia in the organ donor (i.e., blood culture results that were reported to be positive after transplantation) on the outcome of transplant recipients. Twenty-nine of 569 liver and heart donors (5%) had bacteremia at the time of organ procurement, but there were no documented instances of transmission of the isolated bacteria from the donor to the recipient. Unrecognized bacteremia in the donor does not have a negative clinical impact on the outcome of organ transplant recipients.

The spectrum of aortic complications after heart transplantation

BACKGROUND

The connection between the donor and the recipient aorta is a potential source of early and late complications as a result of infection, compliance mismatch, and technical and hemodynamic factors. Moreover, the abrupt change in systolic pressure after heart transplantation involves the entire thoracic aorta in the risk of aneurysm formation. The aim of this study was to analyze the types of aortic complications encountered in our heart transplantation series and to discuss etiology, diagnostic approach, and modes of treatment.

METHODS

Of the 442 patients having orthotopic heart transplantation and the 11 patients having heterotopic heart transplantation at our center, 9 (2%) sustained complications involving the thoracic aorta. These 9 patients were divided into four groups according to the aortic disease: acute aortic rupture (2 patients); infective pseudoaneurysm (3 patients); true aneurysm and dissection of native aorta (2 patients); and aortic dissection after heterotopic heart transplantation (2 patients). Surgical intervention was undertaken in 8.

RESULTS

Five (83%) of 6 patients who underwent surgical treatment for noninfective complications survived the operation, and 4 are long-term survivors. One patient who underwent a Bentall procedure 71/2 years after heterotopic heart transplantation died in the perioperative period of low-output syndrome secondary to underestimated chronic rejection of the graft. One patient with pseudoaneurysm survives without surgical treatment but died several years later of cardiac arrest due to chronic rejection. Both patients operated on for evolving infective pseudoaneurysm died in the perioperative period.

CONCLUSIONS

Infective pseudoaneurysms of the aortic anastomosis are associated with a significant mortality. In noninfective complications, an aggressive surgical approach offers good long-term results. The possibility of retransplantation in spite of complex surgical repair should be considered in the late follow-up after heart transplantation, due to the increasing incidence of chronic rejection.