Effects of volume on outcome in hepatobiliary surgery: a review with guidelines proposal

: The positive relationship between volume and outcome in hepatobiliary surgery has been demonstrated for many years. As for other complex surgical procedures, both improved short- and long-term outcomes have been associated with a higher volume of procedures. However, whether the centralization of complex hepatobiliary procedures makes full sense because it should be associated with higher quality of care, as reported in the literature, precise criteria on what to centralize, where to centralize, and who should be entitled to perform complex procedures are still missing. Indeed, despite the generalized consensus on centralization in hepatobiliary surgery, this topic remains very complex because many determinants are involved in such a centralization process, of which some of them cannot be easily controlled. In the context of different health systems worldwide, such as national health systems and private insurance, there are different stakeholders that demand different needs: politicians, patients, surgeons, institutions and medical associations do not always have the same needs. Starting from a review of the literature on centralization in hepatobiliary surgery, we will propose some guidelines that, while not data-driven due to low evidence in the literature, will be based on good clinical practice.