Surgery for tumors in the abdomen, retroperitoneum, and pelvis requires technical skills and expertise sometimes beyond the capability of a single surgeon. This holds especially true if curative tumor resection involves replacement of arteries and veins, which needs careful planning to avoid long periods of ischemia, and the selection and provision of vascular substitutes according to anatomical position, postsurgical therapy, and adjuncts to avoid thrombosis and infection of vascular grafts. Since the works of Fortner, the value of close collaboration between general and vascular surgeons has been demonstrated, but many of the former even today continue to attempt the operation alone, although the result is not always a masterpiece. The authors refer to their experience in major tumor surgery in either the single management of vascular complications or collaboration. The potential value of close collaboration is presented by negative examples, and a plea is made for a less "eminence"-based management of these sometimes difficult cases, which is based on vast positive experience with vascular diseases of the aorta and the visceral and iliac arteries and veins, including safety measures and adjuncts.