[Background, Necessity and Methodology of the S3 Guideline "Perioperative Management of Gastrointestinal Tumours (POMGAT)"].

Malignancies are among the most common diseases, especially in old age, and are responsible for 25% of all deaths in Germany. Especially carcinomas of the gastrointestinal tract can be cured in most cases only through extensive surgery with significant morbidity. About 25 years ago, the multimodal, perioperative Fast Track (FT) concept for reducing postoperative complications was introduced and additional elements were added in the following years. Meanwhile, there is growing evidence that adherence to the key elements of more than 70% leads to reduction in postoperative adverse events as well as a shorter hospital stay and could be associated with an improved oncological outcome. Despite the high level of awareness and the proven advantages of the FT concept, the implementation and maintenance of the measures is difficult and results in an adherence of only 20 - 40%. There are many reasons for this: In addition to a lack of interdisciplinary and interprofessional cooperation and the time consuming and extended logistical efforts, limited human resources are often listed as one of the main causes. We took these aspects as an opportunity and started to develop a S3 guideline for perioperative treatment to accelerate the recovery of patients with gastrointestinal malignancies. By creating a consensus- and evidence-based, multidisciplinary guideline, many of the problems listed above could probably be solved by optimising and standardising interdisciplinary care, which is particularly important in a setting with many different disciplines and their competing interests. Furthermore, the standardisation of the perioperative procedures will reduce the time and logistical effort. The presentation of the evidence allows increased transparency and justifies the additional personnel expenditure on hospital medicine and health insurance companies. In addition, the evidence-based quality indicators generated during the development of the guideline make it possible to include perioperative standards in certification systems and thus to measure and check the quality of perioperative care.