Introduction: Pancreatic graft thrombosis (PAT) is a major surgical complication, able to cause graft loss in pancreatic transplantation. The recently proposed Cambridge Pancreas Allograft Thrombosis (CPAT) grading system provides diagnostic, prognostic and therapeutic recommendations.

Methods and Results: We retrospectively studied the incidence and grade of PAT using the CPAT grading system in a series of 344 simultaneous pancreas-kidney (SPK) transplant recipients (grafted from 2005 to 2019), who underwent routine CT imaging. The analysis of CT scans, performed independently by a radiologist and a surgeon, revealed signs of PAT in 215 patients (106 grade 1, 85 grade 2, 24 grade 3). In the present study PAT incidence was high because all the recipients underwent CT scan and all grades of thrombosis were considered, contrasting with the majority of studies, where CT scans were not performed routinely in all the recipients but only in those showing graft dysfunction, or following patient symptomatology, and grade 1 thromboses were not considered. The patients who developed PAT were compared to 104 patients with no signs of PAT at the CT scan. Demographic data of the two groups (thrombosis and non-thrombosis) did not show any significant difference, except for the higher number of male donors in the thrombosis group. Pancreatic graft survival was significantly shorter in the thrombosis group.  PAT was cause of graft loss in 41 recipients (11.9%) during the follow-up, but 37 of them (10.8%) have lost their pancreatic graft within the first 30 post-operative days. Graft loss due to PAT was significantly associated with grade 2 and 3 thrombosis. The risk of graft loss did not differ   between recipients with grade 0 or grade 1 thrombosis. In the present study the patients with grade 1 thrombosis had a favorable course since none of them had lost their graft of PAT. On the contrary, patients with grades 2 or 3 were at a significantly higher risk of graft loss due to PAT (7/25 and 17/25, respectively) compared to patients with grades 0 or 1; moreover, whatever the cause of pancreatic graft loss (i.e pancreatitis or bleeding) the risk was significantly associated with the grades 2 and 3. Other factors influencing the occurrence of graft loss were recipient’s age, the development of hyperglycemia, hemorrhage and abdominal pain. PAT did not influence hospitalization duration or patient survival.

Conclusion: The CPAT grading system was successfully implemented in a large series of SPK transplantations and proved applicable in clinical practice. The indications for anticoagulation remain to be studied, although protocol CT imaging and treatment with anticoagulation for partial thrombosis will be standard approach in our patients.