A.M. Green1, G. Ramos-Gonzalez1, M. Mosha1, J. DeRosa1, H. Alemayehu2, C.D. Cappiello3, F. Demehri4, S.M. Kunisaki3, S.E. McLean5, J.A. Meisel2, R.T. Russell6, S. Scholz7, J.A. Taylor8, C.W. Snyder1, N.M. Chandler1 1Johns Hopkins All Children’s Hospital, Division Of Pediatric Surgery, St Petersburg, FLORIDA, USA 2Emory Children’s and Children’s Healthcare of Atlanta, Division Of Pediatric Surgery, Atlanta, GA, USA 3Johns Hopkins Children’s Center, Division Of General Pediatric Surgery, Baltimore, MD, USA 4Boston Children’s Hospital, Department Of Surgery, Boston, MA, USA 5University Of North Carolina At Chapel Hill, Division Of Pediatric Surgery, Chapel Hill, NC, USA 6University Of Alabama at Birmingham, Division Of Pediatric Surgery, Birmingham, Alabama, USA 7Children’s Hospital Of Pittsburgh Of UPMC, Division Of Pediatric Surgery, Pittsburgh, PA, USA 8University Of Florida, Division Of Pediatric Surgery, Gainesville, FL, USA
Introduction: Cross-sectional imaging is often used to determine the severity of pectus excavatum (PE) and may be required prior to surgical repair. After repair, there are few objective clinically useful ways to document improvement in the defect. Our institution developed and validated a novel caliper-based measurement, the modified percent depth (MPD), as an adequate surrogate for other radiographically based indexes (Haller Index/Correction Index). The benefit of MPD measurements is that it can be used to evaluate the defect over time without exposing patients to harmful radiation. The aim of this study was to objectively quantify the PE defect before and after repair utilizing the MPD.
Methods: This was a prospective observational study including 8 hospitals in a multicenter research consortium. Patients with PE who had at least one pre and postoperative MPD measurement were included in this analysis. The MPD was calculated using three measurements of the chest wall; the deepest point of the sternum to posterior midline and posterior midline to maximal point of anterior chest protrusion bilaterally. The MPD was calculated (Figure 1) for each patient pre and postoperatively. Demographics, surgical outcomes and median days between measurements before and after surgery were described. The mean pre and postoperative MPD were compared using paired T-test with significance set at p<0.05.
Results: A total of 250 patients were enrolled from 2021-2024. Sixty-nine had undergone repair of their PE with at least one MPD measurement pre and postoperatively. Mean age of the cohort was 16±1.6; most were male (88%). Most patients underwent minimally invasive repair (98.5%) with 1 bar and 2 stabilizers (92%). The mean postoperative length of stay was 2±1.3 days. The mean pre and postoperative MPD was 22.2±6.9 and 6.8±6.4, respectively. Median (IQR) days from preop MPD to surgery was 9 (0-90) and from surgery to postoperative MPD was 26 (19-55) days. Paired T-test indicated a significant decrease from the pre to postoperative MPD (mean difference =15.4, SD= 8.2, t(df)=15.6(68), p=<.0001).
Conclusion: Caliper-based measurements demonstrated a significant improvement in the mean MPD following pectus excavatum repair. Based on previous studies in normal controls, mean MPD was 4.2 (0.8-11.7), which reassures us that not only is surgery decreasing the PE defect, but also objectively returning the chest wall to near normal. Clinical caliper-based measurements are a reliable method of demonstrating improvement in the chest wall following surgical repair of PE and is an objective process to document the effectiveness of repair. MPD can also be utilized to monitor the long-term longevity of repair after bar removal.