Subunit-Based Intraflap Debulking Technique for Secondary Contouring After Free Flap Reconstruction

Despite advances in surgical technique for flap thinning, secondary debulking is often needed in areas with thin soft tissue coverage. Flaps spanning multiple anatomical subunits pose a particular challenge, as central bulkiness, often located near subunit junctions, is difficult to address with traditional margin-based approaches and may obscure natural contours. We introduced a subunit-based intraflap debulking technique, placing incisions across the flap along anatomical subunit borders and evaluated its safety and effectiveness.

We retrospectively reviewed patients who underwent free flap reconstruction between 2021 and 2025 and later received secondary debulking using this technique. The procedure involved placing intraflap incisions along internal subunit borders, excising central redundant skin and adjacent fatty tissue in a cone-shaped fashion, and reapproximating the flap to restore natural subunit boundaries. Their postoperative outcomes were evaluated.

A total of 22 cases were treated using the subunit-based intraflap approach, most commonly for lower extremity reconstructions, particularly of the foot, with the superficial circumflex iliac artery perforator flap being the most frequently used in the initial surgery. Debulking was performed at a median of 10 months following the initial reconstruction. No postoperative complications, including wound dehiscence, delayed wound healing, seroma, hematoma, or infection, were observed. The median time to complete healing was 14 days. All patients reported satisfaction with the aesthetic outcome.

The subunit-based intraflap debulking technique appears to be a safe approach for secondary contouring after free flap reconstruction in selected cases, allowing effective central debulking and restoration of natural subunit borders.