US Findings in Patients at Risk for Pancreas Transplant Failure

Abstract

Purpose To determine if ultrasonographic (US) findings, including Doppler US findings, are associated with subsequent pancreas transplant failure. Materials and Methods A cohort of adult patients who underwent pancreas transplantation at a tertiary institution over the course of 10 years (from 2003 to 2012) was retrospectively evaluated for failure, which was defined as return to insulin therapy or surgical graft removal. The institutional review board provided a waiver of informed consent. All US images obtained within the 1st postoperative year were reviewed for three findings: arterial flow (presence or absence of intraparenchymal forward diastole flow), splenic vein thrombus, and edema. These findings were correlated with pancreas graft failure within 1-year after surgery by using Cox proportional hazards models and hazard ratios. Results A total of 228 transplants were included (mean patient age, 41.6 years; range, 19-57 years; 122 men, 106 women). Absent or reversed arterial diastolic flow was identified in nine of 20 failed transplants (sensitivity, 45%; 95% confidence interval [CI]: 23, 68) and in 15 of 208 transplants that survived (specificity, 93% [193 of 208]; 95% CI: 89, 96). The Cox proportional hazard ratio was 6.2 (95% CI: 3.1, 12.4). Splenic vein thrombus was identified in 10 of 20 failed transplants (sensitivity, 50%; 95% CI: 27, 73) and in 25 of 208 transplants that survived (specificity, 88% [183 of 208]; 95% CI: 83, 92). The Cox proportional hazard ratio was 4.2 (95% CI: 2.4, 7.4). Edema had the lowest specificity (Cox proportional hazard ratio, 2.0; 95% CI: 1.3, 2.9). In the multivariate analysis, only absent or reversed arterial diastolic flow remained significantly associated with transplant failure (adjusted hazard ratio, 3.6; 95% CI: 1.0, 12.8; P = .045). Conclusion Absent or reversed diastolic arterial Doppler flow has a stronger association with transplant failure than does splenic vein thrombus or edema. (©) RSNA, 2016.

Susceptibility‐directed anticoagulation after pancreas transplantation: A single‐center retrospective study

“…Thrombosis of the distal splenic vein is especially common and is frequently accompanied by minimal or no obvious clinical manifestations. As such, it remains underdiagnosed, under‐reported, and furthermore considered as normal by some . Using early and frequent postoperative sonographic surveillance, we documented the proximal progression of what initially was an isolated distal splenic vein thrombosis in two patients.…”

“…At times, collaterals within the PA prevent ischemia . Therefore, the impact of thrombosis on parenchymal perfusion (diastolic flow) was graded and weighted in the TSS. A limited sonographic scoring of the splenic vein was previously described, while a more generalized, but CT‐based grading was recently proposed …”

“…Recipients were grouped into “graft thrombosis” (n = 36) or “no graft thrombosis” (n = 59), based on the presence or absence of pancreas graft thrombosis during first post‐transplant month, respectively. Our Thrombosis Severity Score (TSS) system is based on three graded parameters: (a) vessel (distal or mid‐splenic vein‐1; proximal splenic v.‐2; superior mesenteric v, portal v, splenic artery, or superior mesenteric artery ‐3; iliac vein or arterial Y‐graft ‐4); (b) occlusion (partial‐1; complete‐2); and (c) parenchymal diastolic arterial flow (normal‐1; absent or reversed‐2) . As such, the score was defined as:…”

Splenic Vein Thrombosis Following Pancreas Transplantation: Identification of Factors That Support Conservative Management

“…Our findings suggest that, in the absence of arterial signal abnormalities on ultrasound, non‐occlusive thrombus in the pancreas graft SV can be successfully treated with anticoagulation. Findings of arterial signal abnormalities on Doppler ultrasound such as absence or reversal of diastolic flow within the graft require urgent operative exploration, since this finding can signal extensive thrombus that may lead to graft loss . This observation may lead to more effective algorithms for the management of this potentially devastating complication.…”

Imaging in pancreas transplantation complications: Temporal classification

“…2,7 The ultrasound findings of venous thrombosis are the absence of venous flow and a high resistance arterial waveform, with reversed diastolic flow. 8 On an unenhanced CT, we may see the venous thrombus as a high-attenuation portal vein or splenic vein, and after the administration of intravenous contrast the thrombus is visualized as a filling defect 9 (Fig. 8).…”