LAUSR

We enjoyed reading Keller et al.'s fascinating article [1] on the benefits of intercostal nerve cryoablation in lieu of thoracic epidural for pectus excavatum. Though very interesting, there are several practical issues with the study that decrease the utility of the cryoablation technique. Our specific and significant concerns with their retrospective study's methodology and analysis include: 1) suboptimal epidural management, 2) lack of standardization of painmanagement, 3) lack of blinding, 4) reoperation for 12% of patients and 5) shorter follow-up. Epidural management reported by the authors is less than optimal compared to our standardized protocol. The primary outcome of this retrospective study, the mean length of stay for patients undergoing pectus repair with intercostal cryoablation, was 3.47 ± 0.83 days, which was significantly shorter than the 5.79 ± 0.93 days in the epidural group. Our epidural patients are typically discharged on postoperative day 3 or 4, comparable to their cyroablation group. Had the authors provided more effective epidural analgesia in their study, there would have been no significant difference between both groups. The lack of standardization of protocol is anothermajor confounding variable. Gabapentin should have been added to both groups or not used at all to negate its effect on a study evaluating the effects of cryoablation alone. The use of additional local anesthetic infusion at the surgical wound is only used in the cryoablation group. At our institution, we have noted significant infection risk with local anesthetic infusions [2] (Apelt N, et al. Accepted for publication in your journal recently). The use of a local anesthetic infusion can cause an intense intercostalmotor block, less pain from sensory block and increasedmobility that could have facilitated bar displacements. Cyroablation could account for this increase in bar displacements as authors agreed. This elucidates our biggest concern that three patients (12%) in the cryoablation group had displacement of their Nuss bar and required reoperation to correct the displaced bar, but none in the epidural group; this is a major clinical and economic concern with cryoablation group.