Right atrial thrombus in an asymptomatic hemodialysis patient with malfunctioning catheter and patent foramen ovale

Abstract

The creation of an accurate functioning arteriovenous fistula has been a long-lasting problem in the hemodialysis setting. In spite of recent guidelines and largely because of the old age of the current dialysis population and a high incidence of diabetes mellitus, atherosclerosis, and related vascular problems, it is not always possible to create an adequate fistula. In that case, long-term tunneled indwelling central vein catheters are a frequently used alternative. Of the many possible complications related to venous access in hemodialysis patients, catheter dysfunction is the most prevalent. We report a 23-year-old female hemodialysis patient in whom such malfunctioning was followed by echocardiography that revealed a large right atrial thrombus (RAT) in close contact to the tip of a long-term indwelling catheter in the presence of a patent foramen ovale. Although RAT is a rare complication in hemodialysis patients, it has very specific therapeutic implications. The present patient underwent a successful surgical atrial thrombectomy. Our experience underscores that in cases of malfunctioning catheter, echocardiographic screening is mandatory.

Large Right Atrial Thrombus Associated with Central Venous Catheter Requiring Open Heart Surgery

“…Type B thrombus forms around foreign bodies in the right atria [3], such as in our case paper. Pathogenesis for type B RAT includes mechanical irritation of the right atrial wall [4], intraluminal clot elongation [5], hypercoagulability in HD patients [6], and fluid dynamics of the right atria [7]. RAT type B may be asymptomatic [3] in presentation as in our case; other associated symptoms may arise from complications of RAT which include pulmonary embolism, systemic embolism, infected thrombi, and hemodynamic compromise [3].…”

“…CRAT is underreported phenomena because of two folds; first, some patients are entirely asymptomatic at presentation of CRAT [7]; second, diagnostic accuracy of TEE may be limited if catheter tip is proximal in superior vena cava [7]. …”

“…In suspected cases, TEE can be done and TEE has a better sensitivity and specificity compared to TTE [7]. Cardiac MRI with gadolinium contrast can be a useful tool for diagnosis and for tissue characterization but was avoided in our case because of risk of nephrogenic systemic fibrosis [8].…”

The Dilemma in Treatment of hemodialysis patients with catheter-induced right atrial thrombi (CRAT): A case report

“…According to Stavroulopoulos et al, surgical thrombectomy is recommended whenever other medical treatments fail or in certain situations like contraindications to anticoagulant therapy, concurrent cardiac abnormalities, presence of endocarditis with cardiac surgery indication and if size of thrombus is ≥ 6 cm. However, one case report suggested that thrombi larger than 2 cm should undergo surgical thrombectomy in the absence of any surgery contraindication [5]. In our case, due to the size and the hypermobility of the thrombus, we postulated that successful rate for medical treatment was low and decided to manage the patient with surgical removal of thrombus.…”

“…Type A thrombi usually form in peripheral veins while type B thrombi develop inside of the right heart atrium and ventricle [4]. CRAT is an underestimated condition, partly because some patients are asymptomatic on presentation and partly by reason of the TTE limitation in diagnosis of CRAT particularly if catheter tip is proximal in superior vena cava (SVC) [5]. TTE has 50 to 60% sensitivity for detection of right heart thrombi while TEE has better sensitivity and specificity [5].…”