The Value of Capsule Thickness on Breast Ultrasound as an Indicator of the Severity of Capsular Contracture and Its Correlation with the Baker Classification

Abstract

Background: We conducted this study to explore the value of the capsule thickness as an indicator of the severity of capsular contracture (CC) alternatively to the Baker classification system in patients who were treated with an implant-based augmentation mammaplasty.

Methods: A total of 117 eligible patients (202 breasts) were included in the current study. We measured the capsule thickness using ultrasound and histologic examination in association with the Baker grades I, II, III and IV. Then, we analysed agreement of the capsule thickness between the two methods using an intra-correlation coefficient (ICC 2,1) with 95% confidence intervals (CIs). The CC of Baker grades II, III and IV (105 breasts), for which the capsule thickness could be measured using US, served as Model 1. Moreover, Model 1 including the CC of Baker grades I (97 breasts) served as Model 2.

Results: The capsule thickness was measured as 0.58 ± 0.11 (0.4-0.8) mm, 1.07 ± 0.16 (0.8-1.31) mm and 1.89 ± 0.55 (1-4.1) mm on ultrasound in association with Baker grades II, III and IV, respectively. In addition, it was also measured as 0.28 ± 0.07 (0.09-0.41) mm, 0.58 ± 0.08 (0.42-0.75) mm, 1.06 ± 0.14 (0.79-1.34) mm and 2.13 ± 1.14 (1.38-6.98) mm on histologic examination in association with Baker grades I, II, III and IV, respectively. In Model 1 and 2, the ICC was calculated as 0.942 (95%CI 0.914-0.961) and 0.955 (95%CI 0.940-0.966), respectively. The cut-off values between the Baker grades I-II, II-III and III-IV were calculated as 0. mm, 0.8 mm and 1.2 mm, respectively.

Conclusions: In conclusion, the capsule thickness might be used as an indicator of the severity of CC alternatively to the Baker classification system. But further studies are warranted to establish our results.

Level of evidence iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Keywords: Breast implants; Capsules; Implant capsular contracture; Microscopic findings; Morphological; Ultrasonography.