The Björck classification of the open abdomen revisited: clarifying concepts for modern complex abdomen management

Abstract Introduction The open abdomen (OA) has become an integral component of modern acute care, trauma, and vascular surgery. Since 2009, the Björck classification, amended in 2016, has provided a common language for describing the status and progression of the OA and remains the most widely used system worldwide. More than fifteen years of international experience, together with advances in temporary abdominal closure, negative pressure wound therapy, mesh-mediated fascial traction, critical care, more timely effective septic source control and abdominal wall reconstruction, have broadened the spectrum of patients encountered and altered the natural history of the OA. In this setting, certain concepts within the classification—particularly developing fixation and the frozen abdomen—are interpreted inconsistently among surgeons and institutions. Materials and methods In this narrative review, we revisit the contemporary application of the Björck classification and argue that its principal current challenge is one of interpretive consistency rather than validity. Conclusion We distinguish OA from complex abdomen, clarify the practical meaning of each grade, and emphasise that anatomical grade describes a current state rather than an inevitable trajectory. The aim is to preserve the simplicity and structure of the original framework while improving communication, research comparability, and clinical decision-making in the management of patients with complex OA conditions. To this end we propose that interpretation is enhanced by considering two complementary domains: a contamination domain, already embedded in the amended system, and a surgical accessibility domain that describes the progressive loss of operative access from free access through developing fixation to loss of lateral access (the frozen abdomen).