Use of Pain Scale VAS Pain Scale Score: The primary end point is the clinical report of pain. Pain intensity will be assessed using a 100 mm VAS with anchors of "no pain" and "worst pain imaginable" and a 4-point category scale ("none", "mild", "moderate", and "severe") once pre-operatively and over the post-operative observation period at 30-minute intervals during the post- surgical time. The category scale is included for purposes of obtaining a patient-reported assignment of moderate pain (definition of clinically significant pain), and for computing the cut-offs for pain sensitivity.