BACKGROUND Graft thrombosis is the leading cause of early graft failure in pancreas transplants. Direct anastomosis grafting of the portal vein to the iliac vein or vena cava generally appears narrowed on postoperative computed tomography (CT) scans. However, modification of surgical techniques may prevent venous narrowing, which also prevents thrombosis-related graft failure. MATERIAL AND METHODS We performed 31 solitary pancreas transplants since 2015. Retrospective analysis of these patients was performed. RESULTS Fence angioplasty was applied in the final 12 cases, and no technical failures or early graft losses occurred in these cases. Three graft losses, including 2 immunologic losses and 1 patient death with functioning graft, occurred after at least postoperative 4 months. The venous anastomoses were evaluated via intraoperative Doppler ultrasound and postoperative CT scans. Intraoperative Doppler ultrasound revealed improved spectral waves of venous anastomoses in the fence group (monophasic spectral wave, 42.9% vs. 0%, p=0.017). The fence-graft applied group had no cases of narrowing, whereas the non-fence group had high narrowing rates on CT scans (84.2% vs. 0%, p<0.001). Furthermore, with less use of postoperative heparin, postoperative bleeding rates were lower in the fence group (36% vs. 0%, p=0.026). CONCLUSIONS Fence angioplasty is a definitive method for avoiding venous anastomotic stenosis and preventing graft failure due to thrombosis.