Quantitative assessment and risk factors for chest wall deformity resulting from tissue expansion for breast reconstruction.

[BACKGROUND] Chest wall deformity after tissue expansion for breast reconstruction is less recognized than complications such as infection, hematoma, skin necrosis and capsular contracture. However, the condition should not be discounted because pain, rib fracture and dyspnea may occur in severe cases. The aim of this study is to evaluate the extent of chest wall deformity quantitatively using computed tomography (CT) and to identify risk factors for this condition after tissue expansion.

[METHODS] The subjects were 34 patients who underwent unilateral two-stage reconstruction and were examined by multidetector-row CT before expander surgery and during maximal tissue expansion. Chest wall deformity was assessed quantitatively using the Chest Wall Deformity Index (CWDI), which was measured before expander surgery (pre-CWDI) and during maximal tissue expansion (post-CWDI). Post minus pre (post-pre) CWDI was used as the index of chest wall deformity in the assessment of risk factors.

[RESULT] Post-CWDI was significantly higher than pre-CWDI (3.66 ± 3.23% vs. 0.03 ± 2.74%, P < 0.001 by paired t test), showing that chest wall deformity occurred after maximum expansion. In a multiple linear regression model, capsular contracture emerged as a significant predictor of increased post-pre CWDI (P = 0.003). BMI was a significant predictor of decreased post-pre CWDI (P = 0.003), but this result may have been due to the measurement method.

[CONCLUSIONS] Our findings suggest that chest wall deformity is common after maximum tissue expansion for breast reconstruction. Awareness of the possibility of chest wall deformity during tissue expansion is important, particularly in cases with capsular contracture.