ClavienDindo

The Clavien-Dindo classification is a standardized system for categorizing postoperative complications by severity. It was introduced in 2004 by Clavien, Demartines, and Dindo and is widely used to provide a consistent framework for reporting surgical outcomes across specialties.

The system assigns complications to five grades (I–V) based on the required therapeutic interventions rather than the underlying cause. Grade I includes minor deviations from the normal postoperative course not requiring pharmacological treatment or operative, endoscopic, or radiological interventions. Grade II requires pharmacological treatment. Grade III necessitates surgical, endoscopic, or radiological intervention, with IIIa performed without general anesthesia and IIIb with general anesthesia. Grade IV encompasses life-threatening complications with single-organ dysfunction (IVa) or multi-organ dysfunction (IVb). Grade V represents patient death.

The Clavien-Dindo classification is valued for its objectivity and reproducibility, enabling meaningful comparisons of surgical quality and risk across studies and registries. It is applicable to a wide range of surgical disciplines and has been incorporated into many clinical trials and quality improvement initiatives. Some adaptations and complementary indices have been proposed to capture the burden of multiple complications or to tailor the system to specific specialties.

Limitations include potential interobserver variability and the challenge of distinguishing planned versus unplanned interventions in some contexts. The classification emphasizes treatment requirements rather than patient-centered impact or functional outcomes, and it may not fully reflect the long-term consequences of certain complications. Nevertheless, Clavien-Dindo remains a widely adopted standard for reporting surgical adverse events.