Systematic classification of morbidity and mortality after thoracic surgery

Background: Objective reporting of postoperative complications is the foundation of surgical quality assurance. We developed a system to identify both presence and severity of thoracic morbidity and mortality, and evaluated its feasibility and utility over the first two years of its implementation.

Methods: The system was based on the Clavien-Dindo classification, in which the severity of a complication is proportional to the effort to treat it. Definitions were developed by peer review and questionnaire. All patients undergoing thoracic surgery (January 2008 to December 2009) were prospectively evaluated.

Results: A total of 953 patients (mean age 61 years; range, 14 to 95) underwent thoracic surgery (total # cases 1260), of which 369 patients had at least one complication (29.3% procedures). Grades I and II include minor complications requiring no therapy or pharmacologic intervention only. Grades III and IV are major complications that require surgical intervention or life support. Grade V complications result in patient death. Grades I, II, III, and IV complications comprised 4.9%, 63.9%, 21.1%, and 7.8% of all complications; overall mortality rate (grade V) was 2.2%. The most common complications were prolonged air leak (18.8%) and atrial fibrillation (18.2%) after pulmonary resection, and atrial fibrillation (11.5%) after esophagectomy-gastrectomy. Prolonged air leak led to a major complication (13%), readmission (17%), or prolonged hospital stay (29%) to a greater extent than atrial fibrillation (3%, 2%, and 7%, respectively).

Conclusions: This standardized classification system for identifying presence and severity of thoracic surgical complications is feasible, facilitates objective comparison, identifies burden of illness of individual complications, and provides an effective method for continuous surgical quality assessment.