Repairing Pretibial and Foot Soft Tissue Defects with Reverse Transplantation of the Medial Crural Fasciocutaneous Flap

The Effect of Perforator Skeletonization on Pedicled Fasciocutaneous Flaps of the Lower Extremity: A Systematic Review

Background Lower extremity defects often require free tissue transfer due to a paucity of local donor sites. Locoregional perforator-based flaps offer durable, single-stage reconstruction while avoiding the pitfalls of microsurgery. Multiple harvest techniques are described, yet few studies provide outcome comparisons. Specifically, no study has examined the impact of perforator flap pedicle skeletonization on reconstructive outcomes. This systematic review characterizes technique and impact of pedicle skeletonization on perforator-based fasciocutaneous flaps of the lower extremity.

Methods PubMed, Scopus, and the Cochrane Central Register of Controlled Trials were reviewed for literature examining perforator-based fasciocutaneous flaps from knee to ankle, from January 2000 through November 2018. The Preferred Reporting Items for Systematic Reviews-Individual Participant Data (PRISMA-IPD) structure was used.

Results Thirty-six articles were included for quantitative analysis. Of 586 flaps, 365 were skeletonized (60.1%) with 58 major (9.9%) and 19 minor complications (3.2%). With skeletonization, overall reoperative rate was higher (odds ratio [OR]: 9.71, p = 0.004), specifically in propeller (OR: 12.50, p = 0.004) and rotational flaps (OR: 18.87, p = 0.004). The complication rate of rotational flaps also increased (OR: 2.60, p = 0.04). Notably, skeletonization reduced complications in flaps rotated 90 degrees or more (OR: 0.21, p = 0.02). Reoperative rate of distal third defects (OR: 14.08, p = 0.02), flaps over 48 cm2 (OR: 33.33, p = 0.01), and length to width ratios over 1.75 (OR: 7.52, p = 0.03) was increased with skeletonization. Skeletonization increased complications in traumatic defects (OR: 2.87, p = 0.04) and reduced complications in malignant defects (OR: 0.10, p = 0.01).

Conclusion Pedicled, perforator-based flaps can provide a reliable locoregional alternative to free tissue transfer for lower extremity defects. Though skeletonization increased the overall reoperative rate, the complication rate for flaps with 90 degrees or more of rotation was significantly reduced. This suggests skeletonization should be considered when large rotational movements are anticipated to reduce complications that can arise from pedicle compression and venous congestion.

Biofabrication of thick vascularized neo-pedicle flaps for reconstructive surgery

Wound chronicity due to intrinsic and extrinsic factors perturbs adequate lesion closure and reestablishment of the protective skin barrier. Immediate and proper care of chronic wounds is necessary for a swift recovery and a reduction of patient vulnerability to infection. Advanced therapies supplemented with standard wound care procedures have been clinically implemented to restore aberrant tissue; however, these treatments are ineffective if local vasculature is too compromised to support minimally-invasive strategies. Autologous "flaps", which are tissues equipped with their own hierarchical vascular supply, can be harvested from one region of the patient and transplanted to the wound where it is reperfused upon microsurgical anastomosis to appropriate recipient vessels. Despite the success of autologous flap transfer, these procedures are extremely invasive, incur obligatory donor-site morbidity, and require sufficient donor-tissue availability, microsurgical expertise, and specialized equipment. 3D-bioprinting modalities, such as extrusion-based bioprinting, can be used to address the clinical constraints of autologous flap transfer, primarily addressing donor-site morbidity and tissue availability. This advancement in regenerative medicine allows the biofabrication of heterogeneous tissue structures with high shape fidelity and spatial resolution to generate biomimetic constructs with the anatomically-precise geometries of native tissue to ensure tissue-specific function. Yet, meaningful progress toward this clinical application has been limited by the lack of vascularization required to meet the nutrient and oxygen demands of clinically relevant tissue volumes. Thus, various criteria for the fabrication of functional tissues with hierarchical, patent vasculature must be considered when implementing 3D-bioprinting technologies for deep, chronic wounds.