Usefulness of the Clavien-Dindo Classification to Rate Complications after Carotid Endarterectomy and Its Implications in Patient Prognosis

Abstract

Our primary objective was to test if the Clavien-Dindo classification (C-D-C) is also applicable for the assessment of carotid surgery and how well it correlates with patient prognosis in the mid-term follow-up. From January 2011 to March 2014, a total of 248 consecutive open surgical carotid revascularization procedures were performed at one academic institution. All patients, symptomatic and asymptomatic, had a high-grade (>70%) stenosis and were operated on under general anesthesia. Physicians graded all complications that were identified in the first 30days after surgery according to C-D-C. Complications were considered "minor" if they were of C-D-C grades I or II. Complications were considered "major" if they were of C-D-C grades III (those requiring surgical, endoscopic, or radiological intervention) or IV (those that are life-threatening). In the analysis of the overall survival, we have found the following differences: (1) survival at 12months (no complication [NC]: 96.3%, minor complications [Cmin]: 94.3%, major complications [Cmaj]: 85.7%), (2) at 24months (NC: 93.1%, Cmin: 92.8%, Cmaj: 64.3%), and (3) at 36months (NC: 87.7%, Cmin: 81.7%, Cmaj: 64.3%). These differences were significant (P=0.014). When analyzing the stroke-free survival after surgery, the survival rates were as follows: (1) at 12months (NC: 94.2%, Cmin: 91.3%, Cmaj: 84.6%), (2) at 24months (NC: 87.7%, Cmin: 82.3%, Cmaj: 61.5%), and (3) at 36months (NC: 81.13%, Cmin: 76.5%, Cmaj: 61.5%). The significance of the difference is P=0.016. In the analysis of cardiovascular event-free survival, taking into account not only stroke and myocardial infarction but also major amputation, the survival analysis shows the following results: (1) at 12months (NC: 90.3%, Cmin: 76.1%, Cmaj: 60%), (2) at 24months (NC: 81.1%, Cmin: 61.1%, Cmaj: 50%), and (3) at 36months (NC: 73%, Cmin: 56.8%, Cmaj: 0%). These data also show a difference between the groups (P<0.001). The C-D-C is applicable for patients who underwent a carotid endarterectomy, and the classification seems to make a good correlation of the grade of the complication and the prognosis during follow-up. More studies are needed with larger numbers of patients and longer follow-up times to clarify the use of the C-D-C after vascular surgery and identify high-risk patients. It can also be helpful to homogenize reports and make them comparable.