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

Area of Science:

• Plastic Surgery
• Surgical Outcomes
• Biostatistics

Background:

• Accurate estimation of resection weight in reduction mammoplasty (RM) is crucial for surgical planning and predicting outcomes.
• Current formulas for estimating resection weight have limitations, complicating insurance approvals and precise surgical planning.

Purpose of the Study:

• To evaluate the accuracy of commonly used formulas for estimating resection weight in reduction mammoplasty.
• To compare calculated resection weights using existing formulas against actual weights in a large patient cohort.

Main Methods:

• A comprehensive literature search identified relevant studies on reduction mammoplasty.
• Regression analysis was performed on a cohort of 1128 reduction mammoplasty patients to assess the accuracy of five common formulas (Appel, Boukovalas, Descamps, Eder, Kocak).
• Calculated resection weights were compared to actual resection weights, with R-squared values determined for different formula applications.

Main Results:

• Analysis included 14 manuscripts encompassing 2232 patients (3320 breasts).
• Regression analyses in the study cohort showed low R-squared values for all tested formulas, indicating poor correlation between calculated and actual resection weights.
• Specific R-squared values varied between formulas and patient groups (e.g., >500g vs. <500g resections), with some formulas yielding indeterminate results.

Conclusions:

• Existing formulas for estimating reduction mammoplasty resection weight are not accurate and are unreliable for surgical planning.
• The observed inaccuracies may stem from formulas being tailored to specific surgical techniques or cohorts.
• Further research is needed to develop more reliable methods for predicting resection weight in reduction mammoplasty.