Preoperative estimation of breast resection weight in patients undergoing inferior pedicle reduction mammoplasty: the Bilgen formula

Resection Weight Formulas for Reduction Mammoplasty: A Systematic Review and Regression Analysis

PURPOSE

Estimating resection weight for patients undergoing reduction mammoplasty (RM) informs surgical planning and outcomes. Existing formulas have limitations that make insurance coverage and accurate surgical planning challenging. We identified the most commonly used scales to evaluate their accuracy in estimating resection weight by applying them to a database of patients to compare calculated and actual resection weights.

METHODS

A database search was conducted using combinations of relevant terms. A regression analysis was conducted using formulas with strong R2 values (0.72-0.93) on a cohort of 1128 RM patients at a single institution.

RESULTS

A total of 570 articles were identified. Fourteen manuscripts (n = 2232 patients [3320 breasts]) were ultimately included for review. Data on incisional patterns, pedicle supply, and breast measurements, such as sternal notch to nipple distance (n = 8 [57.1%]) or nipple to inframammary fold distance (n = 5 [35.7%]), were recorded. R2 values in our cohort (>500 g, n = 891; <500 g, n = 237) were calculated via regression analyses with five formulas: Appel (0.391 vs 0.146), Boukovalas (0.3552 vs 0.043), Descamps (0.391 vs 0.238), Eder (0.328 vs 0.114), and Kocak (0.3283 vs R2 indeterminate).

CONCLUSIONS

Our analysis suggests that formulas reporting strong R2 values may have resulted from tailoring to surgeons' technique. Variation between cohorts is inevitable; however, we expect reliable results given our large sample. It is reasonable to conclude that existing formulas are not accurate representations of resection weights and thus are unreliable for surgical planning.

Impact of sternal notch-to-nipple distance and resection weight asymmetry on complication rates and patient reported outcomes in reduction mammaplasty

While there are numerous predictive models for estimating resection weight, their accuracy may not be strong. Through institutional data of patients who received reduction mammaplasty, this study demonstrates that preoperative sternal notch-to-nipple distance is not an optimal predictive factor for differences in final resection weight, complication rates, and patient reported outcomes. Our results showed that there is a weak correlation between preoperative sternal notch to nipple asymmetry and final resection weight asymmetry. Additionally, significant breast asymmetry is not tied to an increase in complication rates or poorer patient reported outcomes. There is an indication to reconsider the use of such absolute measures for determining who may benefit from reduction mammaplasty.