The graft-to-capacity ratio: volumetric planning in large-volume fat transplantation.

[BACKGROUND] Variability in large-volume fat transplantation has been linked to technique. Meanwhile, the recipient-site volume and its relation to the volume of grafted fat have been relatively overlooked. Graft-to-capacity concepts are evidenced in other soft-tissue transplantation procedures such as skin and hair transplantation. The authors define the graft-to-capacity ratio as the volume of grafted fat in relation to the volume of the recipient site. The authors postulate its theoretical limits, and empirically analyze its potential clinical importance in large-volume fat transplantation.

[METHODS] Thirty cases of large-volume fat transplantation to the breast were reviewed. All patients underwent (1) preoperative quantitative volumetric analysis using three-dimensional breast imaging and (2) large-volume fat transplantation using the large-syringe technique. The volume of fat transplanted into each breast at the time of surgery was noted. Quantitative volumetric breast imaging was repeated 12 months postoperatively.

[RESULTS] The average graft-to-capacity ratio was 117 percent, with a standard deviation of 22 percent, consistent with deduced theoretical limits. Cases where the graft-to-capacity ratio exceeded 1 SD demonstrated lower percentage volume maintenance. Cases where the graft-to-capacity ratio was lower than 1 SD appeared to demonstrate higher percentage volume maintenance. Univariate linear regression of percentage volume maintenance as a function of the graft-to-capacity ratio demonstrated a significant inverse relationship.

[CONCLUSION] The graft-to-capacity ratio appears to be a relevant variable in percentage volume maintenance outcomes and may be useful in establishing consistency in large-volume fat transplantation.

[CLINICAL QUESTION/LEVEL OF EVIDENCE] Therapeutic, IV.