Nuss procedure is proved to be an effective technique for correction of pectus excavatum (PE). However, the cosmetic results for asymmetric morphological varieties have been skeptical because the original Nuss technique often failes to achieve a post-repair symmetry in asymmetric types. Consequently, to solve this problem, we have developed several new techniques for the repair of asymmetric PE. To prove the efficacy of these new techniques by means of numerical analysis, we created new CT indices.
Between August 1999 and April 2004, 469 patients underwent PE repair with our modified Nuss technique in a single institution. We retrospectively analyzed pre and post-operative CT scans of 308 patients in order to calculate new CT indices. The indices are: Depression Index (DI), Asymmetry Index (AI), Eccentricity Index (EI), and Unbalance Index (UI) (Figure 1). Changes of these indices following the repair are evaluated to assess the results of the repair.
Modified techniques applied for each asymmetric type (n=204, 43.5%) were asymmetric bar technique (n=184, 39.2%) for eccentric type; seagull bar technique (n=42, 9.0%) and crest compression technique (n=19, 4.1%) for unbalanced type. DI (2.053+/−2.040 vs. 1, p<0.01) and AI (1.067+/−0.072 vs. 1.021±0.025, p<0.01) were decreased postoperatively. In comparison of AI’s, preoperative values of symmetric and asymmetric type were different (1.036±0.042 vs. 1.107±0.080, p<0.01) but postoperatively the difference became not significant (1.019±0.022 vs. 1.024±0.028, p=0.08), which means asymmetric types are corrected to a symmetric configuration. EI (1.550±0.326 vs. 1, p<0.01) and UI (1.39±0.219 vs. 1, p<0.01) were also decreased postoperatively.
The new CT Indices are useful in precise understanding of the degrees of depression and asymmetries as well as comparing pre and post-operative morphological changes. Assessment of AI revealed that our modifications of Nuss technique are effective in the symmetrical correction of asymmetric PE.
With our modified techniques tailored to each specific type of asymmetry, indications of the Nuss procedure can be expanded to virtually all morphological varieties of PE.
H.J. Park, None.