Venous thrombosis of pancreatic transplants: diagnosis by duplex sonography

Our objective was to determine whether elevated pancreatic transplant arterial resistive index (RI) and absence of venous flow correlate with pancreatic transplant venous thrombosis. Thirteen episodes of surgically documented pancreatic venous thrombosis occurred in 175 pancreases that had been transplanted over a 3-year period. Duplex sonography was performed before surgical exploration in 11 cases. We retrospectively reviewed these 11 sonograms to determine whether blood was flowing in the veins and arteries of the graft. The RI was calculated from all pancreatic artery waveforms. We compared these arterial RIs and the presence or absence of venous flow with those of pancreatic grafts without venous thrombosis to determine sensitivity and specificity. In the venous thrombosis group, thrombosis occurred within 12 days of transplantation (mean, 3.5 days) in all 11 cases. Six cases of thrombosis (55%) occurred within 1 day. Arterial flow was detected within the graft in nine cases (82%) and in the stump of the donor artery between the graft and the recipient iliac artery in the two remaining cases. Antegrade diastolic flow was absent in all arterial tracings. Diastolic flow reversal was present in seven (78%) of nine grafts with detectable intrapancreatic arterial flow. Arterial RIs ranged from 1.00 to 2.00 (mean +/- SD, 1.27 +/- 0.29). Intrapancreatic venous flow was absent in all 11 cases. In the control group (43 examinations in 34 patients) RIs ranged from 0.46 to 1.29 (mean +/- SD, 0.72 +/- 0.18). Two of 43 arterial tracings had diastolic flow reversal (RI > 1.0). Venous flow was present in all examinations in the control group. A statistically significant difference existed between the RIs in the thrombosis group and the RIs in the control group (p = .0001). Reversal of diastolic flow in pancreatic transplant arteries is highly specific for detection of graft venous thrombosis during the first 12 days after transplantation. Our findings suggest that an RI greater than or equal to 1.00 and absence of venous flow, in combination, are highly sensitive and specific for the diagnosis of pancreatic graft venous thrombosis.