Classification system for minimally invasive thyroid surgery

Background: Minimally invasive thyroid surgery has been increasingly embraced in the United States and elsewhere. The surgical standards have yet to emerge, resulting in a sometimes confusing assortment of designations for the techniques. Design:Evidence-based analysis of prospectively collected data from a consecutive, single-surgeon experience with minimally invasive and conventional thyroid surgery. Methods and Materials: Demographic parameters were obtained on patients undergoing thyroid surgery at the Medical College of Georgia from February 2003 to June 2007. Particular attention was paid to patient and tumor characteristics thought to have relevance to eligibility for minimally invasive thyroid surgery. Normally distributed variables were subjected to parametric tests, nonnormally distributed variables to nonparametric tests. Results: A total of 359 patients underwent thyroidectomy during the study period; there were 57 males and 302 females, with a mean (± standard deviation) age of 45.9 ± 15.1 years. Predictably, there was a strongly positive correlation between incision length and both the size of the nodule (p = 0.0001) and the patient body mass index (p = 0.0001). A classification system was designed which established distinct and discrete levels for minimally invasive thyroidectomy (MIT I, II and III). Conclusions: A patient- and disease-driven classification system for assigning eligibility for incremental levels of minimally invasive thyroid surgery is proposed. This system allows for both uniform reporting of outcome measures across patient populations and a logical basis for determining patient eligibility.