The formation of right atrial thrombus (RAT) has been reported in adults as a complication of tunnelled cuffed haemodialysis catheters [1,2] and untunnelled central venous catheters used for non-dialysis indications [3]. We describe the first case of RAT and its management complicating a temporary haemodialysis catheter which had been in situ for 8 weeks, 5 weeks more than the current recommendations [4].
Case. A 39-year-old man with diabetic nephropathy complicated by interstitial nephritis presented with acute renal failure and required urgent haemodialysis. He commenced haemodialysis via a KIMAL 11.5 French 15 cm pre-curved right temporary internal jugular catheter. He received standard intradialytic heparin with a bolus of 2000 U and 1500 U hourly. The temporary catheter was left in situ and not converted to a tunnelled catheter both as it was initially hoped that renal function would improve rapidly and because the patient's long-term goal was for peritoneal dialysis. Eight weeks after insertion of the catheter, he presented with a 2 week history of fever, malaise and arthropathy. Examination revealed a pyrexia of 37.6°C. Serum white cell count was 10.7 x 109/l and his C-reactive protein was 26 mg/l. A chest radiograph showed there was no focus of infection and the catheter tip was high in the right atrium. The patient was not on antimicrobials, and one set of blood cultures was negative. The differential diagnosis was of an inflammatory arthritis or a reaction to Venofer. The catheter was not removed. On the day after admission, a quiet, pan systolic murmur was detected.
An urgent trans-thoracic echocardiogram (TTE) was obtained and showed a large mass adherent to the right atrium. The decision was made to proceed to sternotomy and cardiotomy for examination and removal of the mass. It was felt that attempted thrombolysis may dislodge any thrombus and could cause a fatal pulmonary embolus. The operative findings were of a 4 x 3 cm mass firmly adherent to the right atrial wall. The dialysis catheter was located in the middle of the mass. The mass was removed and the patient made an uneventful recovery. Post-operative examination of the mass showed that it was pure thrombus.
Discussion. There have been 22 cases of RAT reported as a complication of the use of tunnelled cuffed haemodialysis catheters [5]. The presence of infection was associated with a higher mortality of 33% compared with 14% in subjects without infection. The optimal management of dialysis catheter-associated RAT is unclear. Thrombectomy has been reported to be associated with a lower mortality compared with conservative management with anticoagulation and antibiotics; however, this may reflect selection bias, with more stable patients undergoing surgery [5].
It has been suggested that if the thrombus is small (<2 cm), anticoagulation is tried for 6 months followed by a repeat echo and catheter removal. In the presence of bacteraemia, the catheter would be removed first followed by anticoagulation. If the thrombus is larger than 2 cm, especially in the presence of infection, urgent thrombectomy together with antibiotics and anticoagulation should be considered [5].
A recent review [6] has suggested that if haemodialysis is likely to be required for 14 days or more, a tunnelled cuffed catheter (TCC) should be used instead of a temporary uncuffed catheter. The authors report a reduction in both removal rates and infection for TCCs, although no cases of RAT were encountered. This strategy might help reduce the rate of catheter-related thrombotic complications, given that uncuffed catheters are more thrombogenic than TCCs and would have been an appropriate choice in the case presented.
The case we present highlights a serious complication of a short-term catheter used for longer-term haemodialysis access. If RAT complicates a temporary catheter used for long-term access, the management will be similar to that of RAT complicating a tunnelled catheter and depends on the size of thrombus and the presence of bacteraemia.
Conflict of interest statement. None declared.
Renal Unit Royal Devon and Exeter Hospital Barrack Road Exeter EX2 5DW Email: gavin_dreyer{at}hotmail.com
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