TY - JOUR
T1 - An external validation of a novel predictive algorithm for male nipple areolar positioning
T2 - an improvement to current practice through a multicenter endeavor
AU - Timmermans, Floyd W.
AU - Ruyssinck, Laure
AU - Mokken, Sterre E.
AU - Buncamper, Marlon
AU - Veen, Kevin M.
AU - Mullender, Margriet G.
AU - Claes, Karel E.Y.
AU - Bouman, Mark Bram
AU - Monstrey, Stanislas
AU - van de Grift, Timotheus C.
N1 - Funding Information: We would like to thank all the participants for their contribution. Publisher Copyright: © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
PY - 2023
Y1 - 2023
N2 - The correct positioning of nipple-areolar complexes (NAC) during gender-affirming mastectomies remains a particular challenge. Recently, a Dutch two-step algorithm was proposed predicting the most ideal NAC-position derived from a large cisgender male cohort. We aimed to externally validate this algorithm in a Belgian cohort. The Belgian validation cohort consisted of cisgender men. Based on patient-specific anthropometry, the algorithm predicts nipple-nipple distance (NN) and sternal-notch-to-nipple distance (SNN). Predictions were externally validated using the performance measures: R 2-value, means squared error (MSE) and mean absolute percentage error (MAPE). Additionally, data were collected from a Belgian and Dutch cohort of transgender men having undergone mastectomy with free nipple grafts. The observed and predicted NN and SNN were compared and the inter-center variability was assessed. A total of 51 Belgian cisgender and 25 transgender men were included, as well as 150 Dutch cisgender and 96 transgender men. Respectively, the performance measures (R 2-value, MSE and MAPE) for NN were 0.315, 2.35 (95%CI:0–6.9), 4.9% (95%CI:3.8–6.1) and 0.423, 1.51 (95%CI:0–4.02), 4.73%(95%CI:3.7–5.7) for SNN. When applying the algorithm to both transgender cohorts, the predicted SNN was larger in both Dutch (17.1measured(±1.7) vs. 18.7predicted(±1.4), p= <0.001) and Belgian (16.2measured(±1.8) vs. 18.4predicted(±1.5), p= <0.001) cohorts, whereas NN was too long in the Belgian (22.0measured(±2.6) vs. 21.2predicted(±1.6), p = 0.025) and too short in the Dutch cohort (19.8measured(±1.8) vs. 20.7predicted(±1.9), p = 0.001). Both models performed well in external validation. This indicates that this two-step algorithm provides a reproducible and accurate clinical tool in determining the most ideal patient-tailored NAC-position in transgender men seeking gender-affirming chest surgery.
AB - The correct positioning of nipple-areolar complexes (NAC) during gender-affirming mastectomies remains a particular challenge. Recently, a Dutch two-step algorithm was proposed predicting the most ideal NAC-position derived from a large cisgender male cohort. We aimed to externally validate this algorithm in a Belgian cohort. The Belgian validation cohort consisted of cisgender men. Based on patient-specific anthropometry, the algorithm predicts nipple-nipple distance (NN) and sternal-notch-to-nipple distance (SNN). Predictions were externally validated using the performance measures: R 2-value, means squared error (MSE) and mean absolute percentage error (MAPE). Additionally, data were collected from a Belgian and Dutch cohort of transgender men having undergone mastectomy with free nipple grafts. The observed and predicted NN and SNN were compared and the inter-center variability was assessed. A total of 51 Belgian cisgender and 25 transgender men were included, as well as 150 Dutch cisgender and 96 transgender men. Respectively, the performance measures (R 2-value, MSE and MAPE) for NN were 0.315, 2.35 (95%CI:0–6.9), 4.9% (95%CI:3.8–6.1) and 0.423, 1.51 (95%CI:0–4.02), 4.73%(95%CI:3.7–5.7) for SNN. When applying the algorithm to both transgender cohorts, the predicted SNN was larger in both Dutch (17.1measured(±1.7) vs. 18.7predicted(±1.4), p= <0.001) and Belgian (16.2measured(±1.8) vs. 18.4predicted(±1.5), p= <0.001) cohorts, whereas NN was too long in the Belgian (22.0measured(±2.6) vs. 21.2predicted(±1.6), p = 0.025) and too short in the Dutch cohort (19.8measured(±1.8) vs. 20.7predicted(±1.9), p = 0.001). Both models performed well in external validation. This indicates that this two-step algorithm provides a reproducible and accurate clinical tool in determining the most ideal patient-tailored NAC-position in transgender men seeking gender-affirming chest surgery.
KW - Mastectomy
KW - anthropometry
KW - gender surgery
KW - morphology
KW - nipple reconstruction
KW - transgender individual
UR - http://www.scopus.com/inward/record.url?scp=85118669552&partnerID=8YFLogxK
U2 - https://doi.org/10.1080/2000656X.2021.1994982
DO - https://doi.org/10.1080/2000656X.2021.1994982
M3 - Article
C2 - 34743656
SN - 2000-656X
VL - 57
SP - 103
EP - 108
JO - JOURNAL OF PLASTIC SURGERY AND HAND SURGERY
JF - JOURNAL OF PLASTIC SURGERY AND HAND SURGERY
IS - 1-6
ER -