Assessment of Viability of the Pancreas for Transplantation Using Contrast-Enhanced Ultrasound

IntroductionThe main concern in pancreas transplantation is potential thrombosis of the graft due to poor perfusion.AimTo assess the viability of the pancreas before transplantation by using contrast-enhanced ultrasound scan (CEUS).MethodsTen harvested pancreatas were studied using an iU22 (Philips, Bothell, USA) scanner together with an L9-3 linear probe for the CEUS. The ultrasound contrast agent SonoVue (Bracco spa, Milan), which is a commercially available second-generation microbubble-based agent, can be visualized in real time at low acoustic pressure (mechanical Index of 0.06). Prior to transplantation, the pancreas is placed in Via Span solution (Bristol-Mayer Squibb AB, Bromma, Sverige). Baseline conventional scale sonography is first performed to assess the parenchyma, which appears as homogenous soft tissue. The donor pancreas arterial supply is cannulated (16 gauge) and infused with Via Span solution. Two milliliters of SonoVue is slowly injected and the pancreas is scanned using the low MI nonlinear imaging mode to visualize the microbubbles enhancement of the pancreas to ensure uniform perfusion of the whole organ. Perfusion was scored visually (0 to 5) subjectively by two observers.ResultsFour grafts were not transplanted for different reasons. Lack of a recipient was the cause in one case with a high score (case 1). Cases 4 and 5 were turned down based on clinical evaluation, and arterial thrombosis was the cause in case 7. The last three cases showed a low mean perfusion score of 1.2. Of the six transplanted pancreatas, the four, that were successfully transplanted displayed a mean perfusion score of 4, compared with a mean score of 1.5 for the two cases who suffered rejection following transplantation.ConclusionCEUS offers the potential to assess the perfusion of the pancreas transplant preoperatively, which may improve the selection criteria and potentially impact the outcomes of transplantation.