Preface

The field of organ transplantation continues to evolve and is a highly effective therapy for patients with end-organ dysfunction (liver, kidney, pancreas, heart, lung) with a wide range of medical conditions. Improvement of perioperative care, surgical technique and immunosuppression in recent years has led to the transformation of organ transplantation into a safe and routine procedure with steadily improving results.

Organ donation plays a key role in the transplant process and corresponds to many fields of medical knowledge as well as social and ethical aspects. New advancements in surgery have allowed for more efficient and refined multi-organ procurements with minimal complications and decreased ischemic injury events. However, the increasing number of patients on transplant waiting lists and the limited donor pool have led to increased demand for new approaches, such as splitting organs, living donation and tissue engineering. In recent years, trends halve shifted towards marginal grafts, which are grafts from higher-risk donors.

Transplantation is a complex process that requires the effort and effective collaboration of a wide range of medical specialists (medical doctors, surgeons, anesthesiologists, psychologists, coordinators, etc.) and institutions. Good results are a function of the proper selection of donors and recipients. Further research will lead to a better understanding of the pathophysiology of the immune response and help scientists to develop more effective strategies for improving graft and patient survival.

> **Vassil Mihaylov, MD, PhD, FACS** Associate Professor, HPB and Transplant surgery, Military Medical Academy, Sofia, Bulgaria
