Quantitative Analysis of Nipple to Inframammary Fold Distance Variation in Tuberous Breast Augmentation: Is there a Progressive Lower Pole Expansion?

[INTRODUCTION] In patients with short nipple to inframammary fold (N-IMF) distance, as in tuberous breast, the cohesivity and gel distribution of shaped implants work as a controlled tissue expander, progressively adapting the tissues to the implant's shape. This phenomenon translates into a gradual increase of the N-IMF distance over time, but the true extent to which this occurs has not been quantified to date. This study aims to quantify the postoperative variation of the N-IMF distance in tuberous breast treated with shaped cohesive silicone breast implants.

[METHODS] We did a retrospective review of a prospective maintained database of all consecutive patients with bilateral Groulleau I and II tuberous breasts who underwent primary breast augmentation between April 2017 and May 2018 at our institution. To quantify the lower mammary pole's morphological changes, we evaluated the N-IMF distance under maximal stretch as an endpoint. We recorded this value at time 0 (preoperative), immediate post-op (equivalent to the distance planned preoperatively) and at month 1, month 6 and 1-year post-op. Then we calculated the average N-IMF distance variation of our sample of patients with a 99% interval of confidence for each breast obtained. Comparisons were performed using the Sign test and the Mann-Whitney U test.

[RESULTS] The average implant weight was 353g (range 290-450; SD ±46.147). Of the 54 breasts analyzed, the immediate post-op N-IMF distance was on average 2.43 cm longer than the preop IMF with a 99% confidence interval between 2.01 and 2.86 and SD of ±1.22. The mean difference between the preop N-IMF distance and after 1, 6 and 12 months was respectively 2.78 cm (SD,1.56) (99% CI, 2.24-3.34), 3.08 cm (SD, 1.57) (99% CI, 2.53-3.64), and 3.36 (1.55) (99% CI, 2.82-3.91) Comparing immediate postoperative nipple to inframammary fold distance (N-IMF) to the 1, 6 and 12 months N-IMF values, an average of 4.23% (CI 1.3-7.16), 7.74% (CI 4.25-11.23) and 10.84% (CI 7.21-14.49) of skin length, was gained respectively. According to implants' weight, subgroup analysis showed that implants > 400 g were associated with significantly higher N-IMF distance increase (p <0.05) compared to implants < 400 g.

[CONCLUSIONS] Our findings suggest that a significant progressive postoperative increase in N-IMF distance should be expected in all cases of tuberous breast augmentation with anatomical implants over a 1 year period. This aspect may have an important implication on the IMF incision and the new fold position preoperative planning. LEVEL OF EVIDENCE IV.