Power 80% A sample size calculation comparing proportions was performed which compared 0.55 (bundled cords) incidence of thermal injury versus 0.23 (unbundled cords) incidence of thermal injury. A sample size of 36 per group has the power (1-β) 0.80 to detect a difference assuming α=0.05. We estimate a 15% dropout rate (this would be individuals who between their consent in pre-operative clinic and their operation decide to withdraw from the study). A 15% dropout rate is conservative in light of our prior experience recruiting similar patients when 0% (0/40) of individuals dropped out. Total sample size is estimated to be 72 (36 for each of two groups) plus 11 (15% dropout) for a total of 84 subjects.