We would like to thank Wurtz and colleagues for their comments on our article documenting the 4-year follow-up of the first tissue-engineered total tracheal replacement in a child (1). Although the fate of the tracheal allograft cannot be determined with certainty, serial endoscopy and computed tomography indicated that the graft embedded within the stent and remodeled over time, with growth occurring at the proximal and distal nonstented areas (Figure 1). Despite the loss of mechanical integrity when using a decellularized method, this case remains the most successful circumferential total tracheal replacement reported, albeit after several months of intensive treatment and the need for stenting. We look forward to reading the outlined large animal investigation using a cryopreserved allograft and hope to see biomechanical data to compare with our decellularized method. An omental-flap wrap is a useful technique prior to transplantation, as has been reported in bladder, bowel, and esophageal replacement (2-4); however, because of the emergent nature of our case, prevascularization was not possible. Instead, part of the omentum was transposed at the point of transplantation (5).Examples of circumferential tissue-engineered tracheal replacements to date have been limited by an ineffective mucosal layer. Respiratory mucosa provide a barrier against infection, allow for mucociliary clearance and may reduce fibroblastic infiltrate and subsequent stenosis (6). The use of an acellular stented allograft, as proposed by Wurtz and colleagues, might be possible in short segment replacements in which the distance for reepithelialization from the wound edge is small; however, conventional surgical techniques can currently address short segment disease. We would have concerns about adopting such an approach in a longsegment or total tracheal replacement in all but the most extreme circumstances because the length of time needed for reepithelialization-in our case, >12 months despite intraoperative attempts at epithelializationplaces the patient at risk of complications from infection, granulation and mucus retention. More research is needed into the isolation and expansion of epithelium for mucosal regeneration and into methods that reconstruct and deliver a functional mucosal layer within bioengineered airways.