A TECHNIQUE TO PREVENT BAR DISPLACEMENT IN THE NUSS PROCEDURE
Claire E. Graves, MD1, Andrew Phelps, MD1, Olajire Idowu, Jr., MD2, Sunghoon Kim, MD2, Benjamin E. Padilla, MD1.
1University of California, San Francisco Benioff Children’s Hospital, San Francisco, CA, USA, 2University of California, San Francisco Benioff Children’s Hospital, Oakland, CA, USA.
Purpose: Bar displacement is a serious complication of the Nuss procedure. Three types of displacement have been well described: lateral sliding, bar flipping and posterior disruption. We propose a simple modification in bar placement and fixation that safeguards against all three mechanisms of displacement.
Methods: Nuss bar length is chosen to extend just beyond the pectus ridge on each side. Using the external bar bender, we make a gentle curve on each side of the bar, corresponding to the peak of each pectus ridge. The ends of the bar are left straight. After the bar is inserted and flipped, a stabilizer is placed on each end and slid medially, just lateral to the chest wall insertion site. After the stabilizers are in position, in situ bar benders are used to complete the curvature of the bar around the chest wall.
Results: This technique addresses all three methods of displacement (Fig.1). Lateral sliding is prevented by locking the stabilizers in place with in situ bending just lateral to the chest exit site (A). The bar cannot move laterally as the stabilizers abut the chest wall exit site (B). Placing the stabilizers more medially positions them at the inflection point where the ribs angle superiorly. Thus the stabilizers straddle two ribs on the anterior chest (C). The stabilizers therefore have a broader base of support, preventing bar flipping. Finally, placing the stabilizers more anterior allows them to directly counteract the posterior pressure on the bar from the sternum. Instead of relying on the intercostal musculature, the ribs themselves serve to support the stabilizers and bar from posterior dislocation.
Conclusion: We report a technical modification of pectus bar placement and stabilization to minimize the risk of three common mechanisms of displacement.