Why do pancreas transplants thrombose?

Hypercoagulable state associated with kidney-pancreas transplantation. Thromboelastogram-directed anti-coagulation and implications for future therapy

BACKGROUND

The clinical consequences of type 1 diabetes mellitus (IDDM) include diabetic triopathy: retinopathy, nephropathy, and neuropathy, as well as microangiopathy, accelerated atherosclerotic disease, and hypercoagulability. The etiology of the hypercoagulability is multifactorial, involving various clotting factors or pathways (for example platelets, fibrinogen, individual components of the clotting system and/or fibrinolysis in different studies). The development of end-stage renal disease (ESRD), with the uremia-related platelet effect has the potential to protect from the existing hypercoagulable state. This has important implications for surgery, particularly simultaneous pancreas-kidney (SPK) transplantation, where the pancreas has historically been prone to thrombosis. This has led us to perform intra-operative thromboelastograms (TEG's) to evaluate the patient's current coagulation status.

METHODS

A TEG was performed in 85 SPK recipients along with a control group of 54 non-diabetic kidney transplant (KT) recipients.

RESULTS

For each of the 4 TEG coagulation parameters, the SPK recipients were significantly more hypercoagulable than the non-diabetic KT recipients. The use of intra-operative heparin is based on the degree of hypercoagulability by TEG and degree of operative hemostasis. There has been one PT lost to thrombosis (1%) in the first week following transplantation during this time.

CONCLUSION

The use of TEG is a helpful adjunct to SPK surgery, demonstrating the patient's current coagulation status. Nearly all SPK recipients (type 1 IDDM with ESRD) have been demonstrated to be hypercoagulable. The TEG allows the judicious use of anti-coagulation at the time of surgery, and beyond.