73.13 The Effect of Growth on Serial Haller Indices

Posted on January 18, 2016

A. S. Poola1, B. G. Dalton1, K. W. Gonzalez1, D. C. Rivard2, J. F. Tobler2, C. W. Iqbal1 1Children’s Mercy Hospital – University Of Missouri Kansas City,Pediatric Surgery,Kansas City, MO, USA 2Children’s Mercy Hospital – University Of Missouri Kansas City,Radiology,Kansas City, MO, USA

Introduction:
The Haller Index (HI) has been used as a marker for severity of pectus excavatum. However, how the HI may be affected by growth of the chest wall over time is unknown. Understanding this effect would be valuable in determining if the HI is a useful and objective measure of correction in pectus excavatum; specifically, patients undergoing investigational techniques for repair such as magnetic correction which results in a more gradual change of the chest wall

Methods:

A single institution, retrospective chart review from 2004-2014 was conducted. Patients aged 0-18 years without known chest wall deformities that underwent at least 5 computed tomography (CT) scans were included to assess for changes in the anterior-posterior (AP) dimension, transverse dimension, and the HI.

Results:
Forty-four patients were identified. All patients had an oncologic diagnosis for which serial chest CT scans were obtained. 59 percent of the patients were male. The mean age at initial CT evaluation was 12 years (range: 4-16 years). The mean time between initial and 5th CT scan was 41 months (range: 7-80 months). Over that period, the mean change in height was 10 cm (range: 0-32 cm). Thirty two patients grew more than 5 cm during this time. The mean AP diameter changed at a different rate than the mean transverse diameter (0.9 versus 1.6 cm, p=0.005). This affected the HI over that time which differed by a mean of 0.2 (range: 0.0-0.8).

Conclusion:
Based on serial CT imaging, the rate of growth of the AP diameter and the transverse diameter of the chest varies over time which can affect the HI by as much as 0.8. Therefore, other objective measures should be sought that may more effectively measure pectus excavatum severity for use in investigational trials.