The correction index: Setting the standard for recommending operative repair of pectus excavatum

Background The Haller index, derived from a chest computed tomography scan, remains the standard for determining candidacy for pectus excavatum repair (Haller index ≥3.25). However, it has been suggested that this index may not accurately reflect pectus severity in patients with abnormal chest wall morphologies. This study explores a new, more appropriate criteria for recommending repair based on a correction index, while still incorporating the standard set by the Haller index. Methods A database of 75 patients with pectus excavatum who received computed tomography scans was compiled. For each patient, a staff radiologist calculated the Haller index, a correction index, and an ideal chest index from the computed tomography image with the greatest sternal depression. A correlation was assessed between all Haller and correction indices and separately for those with standard and nonstandard chest dimensions as assessed by an ideal chest index. Results There was a modest correlation between the Haller and correction indices measured in this cohort (r = 0.79; p < 0.0001). When patients with aberrant ideal chest dimensions were removed from analysis, Haller and correction indices showed a stronger correlation (r = 0.86; p < 0.0001). Conclusions The correction index provides an accurate assessment of pectus severity, and by the nature of the measurement, reflects the potential degree of operative repair. The Haller index correlates well with the correction index in pectus patients with standard chest wall dimensions, but is quite discrepant in the nonstandard chest. We recommend operative repair for pectus excavatum with a correction index of 28% or more, because this value correlates with the long-accepted standard (Haller index ≥3.25) and this index remains accurate even in nonstandard chest morphologies.