The Clavien-Dindo Classification

The therapy used to correct a specific complication is the basis of this classification in order to rank a complication in an objective and reproducible manner.


It consists of 7 grades (I, II, IIIa, IIIb, IVa, IVb and V). The introduction of the subclasses a and b allows a contraction of the classification into 5 grades (I, II, III, IV and V) depending on the size of the population observed or the of the focus of a study.


Complications that have the potential for long-lasting disability after patient’s discharge (e.g.: paralysis of a voice cord after thyroid surgery) are highlighted in the present classification by a suffix (“d” for disability). This suffix indicates that a follow-up is required to comprehensively evaluate the outcome and related long-term quality of life.



Grade IAny deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions
Allowed therapeutic regimens are: drugs as antiemetics, antipyretics, analgetics, diuretics and electrolytes and physiotherapy. This grade also includes wound infections opened at the bedside.
Grade IIRequiring pharmacological treatment with drugs other than such allowed for grade I complications.
Blood transfusionsand total parenteral nutritionare also included.

Grade III

Requiring surgical, endoscopic or radiological intervention

       - IIIa

Intervention not under general anesthesia

       - IIIb

Intervention under general anesthesia

Grade IV

Life-threatening complication (including CNS complications)* requiring IC/ICU-management

       - IVa

single organ dysfunction (including dialysis)

       - IVb

Grade VDeath of a patient


*brain hemorrhage, ischemic stroke, subarrachnoidalbleeding,but excluding transient ischemic attacks (TIA);IC: Intermediate care; ICU: Intensive care unit.






Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004; 240(2):205-213.


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Clavien PA, Barkun J, de Oliveira ML, et al. The Clavien-Dindo classification of surgical complications: five-year experience. Ann Surg 2009; 250(2):187-196.


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Slankamenac K, Graf R, Barkun J, et al. The comprehensive complication index: a novel continuous scale to measure surgical morbidity. Ann Surg 2013; 258(1):1-7.


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