Flap Thinning Technique: The Effect of Primary Flap Defatting

Sir: This communication is a commentary on the article entitled “Experimental Animal Model Proving the Benefit of Primary Defatting of Full-Thickness Random-Pattern Skin Flaps by Suppressing Perfusion Steal” by Chetboun and Masquelet (Plast. Reconstr. Surg. 120: 1496, 2007). We believe that this study will have a major impact on flap surgery. Moreover, it agrees with our previous anatomical and clinical studies1–3 that showed that the survival area of primary thinned random-pattern flaps is much larger than that of thick random-pattern flaps. Our focus on flap thinning techniques for over 15 years has allowed us to harvest extremely thin but large flaps that we use primarily to reconstruct large areas such as the face and neck. Our flaps are sometimes called “superthin flaps” (Fig. 1).1–3 The flap is primarily thinned to the layer where the subdermal vascular network (subdermal plexus) can be seen through the minimal fat layer. Moreover, much longer and larger flaps can be harvested according to the selection of the perforators attached to the flaps.Fig. 1.: The superthin flap. In this operation, we used curved scissors to avoid damaging the subdermal plexus. The flap is quite thin and the contour of the clavicle can be clearly seen in this clinical case.Our colleagues, Gao et al., reported experiments about the survival area of thin flaps using pigs in 1999 and 2000,4,5 and we introduced their studies in our other articles written in English.2,3 In their reports, they concluded that (1) the survival area of thin “random-pattern flaps” is much larger than that of thick random pattern flaps (Fig. 2); (2) in thin random pattern flaps, the survival area depends on the relationship between pedicle width and flap width; and (3) in thin random pattern flaps, the flaps with a pedicle width–to–flap width ratio of 1:2 have the largest survival area, and the limit of the surviving flap length is twice the flap width.Fig. 2.: Anatomical study of flap thinning. We have also confirmed that the survival area of thin so-called random pattern flaps is much larger than that of thick random pattern flaps, as mentioned in the study by Chetboun and Masquelet. The drawings show pedicle to width ratios of 1:1, 1:2, and 1:3 (left to right), with corresponding flap lengths and (in white) surviving areas. (Ogawa, R., Hyakusoku, H., Murakami, M., and Gao, J. H. Clinical and basic research on occipito-cervico-dorsal flaps: Including a study of the anatomical territories of dorsal trunk vessels. Plast. Reconstr. Surg. 113: 1923, 2004.)The results of our studies are consistent with the results of the report by Chetboun and Masquelet, in which plastic sheets were placed under the flap to suppress revascularization from the wound bed. We agree that this technique is helpful for studying blood flow from the skin pedicle. However, as revascularization from the wound bed can be considered to occur 2 or 3 days after the operation in a natural setting, there is a possibility that the congestion of the thin flap could be improved faster than that of thick flaps. Moreover, we should also discuss what constitutes a random-pattern flap and what constitutes an axial-pattern flap. Before the recent development of perforator flaps, blood flow from cutaneous perforators was considered not to have an “axial pattern.” Thus, the blood flow from the perforators in the pedicle of flaps in the study of Chetboun and Masquelet should have been studied by angiography. In future studies, we should consider these minor but nonetheless potentially important issues. However, we would like to compliment the authors on the results of their study, which are very encouraging and point the way to better flap surgery. Rei Ogawa, M.D., Ph.D. Hiko Hyakusoku, M.D., Ph.D.