A novel device for measurement of subglottic stenosis in 3 dimensions during suspension laryngoscopy.

Abstract

A challenge in treating subglottic stenosis is assessment of airway caliber before and after management. At present, surgeons lack a simple, efficient, and precise method of measuring subglottic stenosis intraoperatively. We present a novel, easily reproducible tool for measurement of the diameter, location, and length of subglottic stenosis during suspension laryngoscopy. A set of 5 Kirschner wires (30-cm length and 1.6-mm diameter) were bent 90° at both ends to produce a series of 10 short ends designed to measure airway diameter (0.3- to 2.1-cm length with 2-mm intervals). Short, bent ends of the measuring sticks were designed to measure airway diameter. Hash marks at 2-mm intervals were created along the long axis of the measuring sticks to measure subglottic stenosis length and location relative to the vocal cords. The measuring stick was tested in 10 adult patients undergoing suspension microlaryngoscopy for endoscopic treatment of subglottic stenosis between September 2012 and July 2013. The accuracy of the measuring stick was evaluated using an airway phantom. The measuring stick enabled easy and precise quantification of subglottic stenosis diameter (82.5% agreement with reference; interobserver agreement, r = 0.995; P < .001), length (72.5%; r = 0.995; P < .001) and location during suspension laryngoscopy. The measuring stick is inexpensive and simple to construct. It allows for safe, accurate, and practical measurement of subglottic stenosis diameter, length, and location during suspension laryngoscopy.