Case report: atypical fungal obstruction of the left ventricular assist device outflow cannula

Abstract

We describe a very rare case of outflow cannula obstruction with fungal infectious thrombus formation. Discussion includes the etiology, diagnosis, and management of fungal infection complications related with long-term mechanical circulatory support. Left ventricular assist devices (LVADs) are increasingly used as bridge to transplant and permanent long-term therapy in the population with end-stage heart failure. Even though better clinical outcomes have been achieved with the newer-generation continuous-flow devices, infection complications are still a major risk for patients with continuous-flow LVAD implantation in long-term follow-up [Ann Thorac Surg 90:1270-1277, 2010]. Device-related infections can be categorized as driveline infections, pump-pocket infections, and LVAD-associated endocarditis [Expert Rev Med Devices 8: 627-634, 2011]. The microbiological profile is very heterogeneous; the most common pathogens are Staphylococcus, Pseudomonas, Streptococcus species, and Candida. Severe fungal infection may lead to dysfunction of the LVAD due to obstructive mass formation within the device. Due to the only anecdotal reports in the current literature, we present a very rare case of outflow fungal infectious thrombus formation leading to outflow cannula obstruction in patient with LVAD.

Fungal prosthetic aortic valve endocarditis and endarteritis: An unusual cause of aortic root vegetations

“…Candida endocarditis has been known to affect both native and prosthetic valves, and vegetations affecting all four heart valves have been well documented in the literature. 38,39 Extracardiac sites of infection following Candida endocarditis have also been described. [22][23][24][25][26] Exogenous material in the body, such as CEID, are particularly susceptible to infection with C albicans as the microorganism produces a highly organized biofilm covered in an extracellular matrix that facilitates binding.…”

Endocarditis in left ventricular assist device

“…In bacterial endocarditis, the reported complications include mycotic embolism causing intraparenchymal bleeding and systemic mycotic emboli (2,(22)(23)(24)(25)(26). In fungal endocarditis, the reported complications include vegetation obstructing the inflow and outflow valves and also obstruction of the outflow cannula (20,29,31).…”

“…All high-risk patients on LVAD should be treated with fluconazole prophylaxis. Patients diagnosed with candida endocarditis should be treated with an echinocandin (20). Prophylaxis for aspergillosis is not routinely administered.…”

“…Eventually, his blood cultures came back negative after a prolonged course of antibiotics but the patient died due to other complications (24). species (20). Staphylococcus aureus is the most common pathogen in LVAD endocarditis, which has the propensity to adhere itself due to possession of Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMM) (21).…”

“…Out of the 7 patients reported with fungal endocarditis, 6 of them had anti-fungal treatment and LVAD explantation. Heart transplantation was done in 5 of the patient due to the availability of donor's heart (20,29,31). But it's strongly emphasized that eradication of fungemia with drugs alone without LVAD removal is an impossible task (15).…”