Introduction: The reconstruction of large posterior trunk defects can be challenging and frequently requires free tissue transfer. These defects are often the result of post-oncologic resection, and patients commonly receive perioperative radiotherapy. The use of free tissue transfer may increase the complexity of the reconstructions because of the limited availability of recipient vessels, need for intraoperative patient repositioning, and frequent inability of a single flap to cover these defects. There are few published reports on the use of multiple concurrent locoregional flaps for these challenging defects.

Methods: At The University of Texas M. D. Anderson Cancer Center, we have adopted a strategy for reconstruction of large posterior trunk defects using multiple pedicled muscle, musculocutaneous, and/or fasciocutaneous flaps to avoid free tissue transfer. The algorithm includes proper patient selection, systematic analysis of the defect and unresected locoregional tissue and evaluation of cutaneous coverage. We present a series of patients in whom 3 or more separate locoregional flaps were concurrently used to reconstruct massive posterior and lateral trunk defects after oncologic resection. The technique, patient and flap selection, pitfalls, and outcomes using this reconstructive algorithm are discussed.

Results: Three representative cases with various defect locations and characteristics are presented. Patient 1 underwent resection of a radiation induced osteosarcoma including full-thickness posterior chest wall, a left upper lobectomy, and multilevel partial vertebrectomies resulting in a 25 x 30 cm defect. Polypropylene mesh was used to close the (15 x 25 cm) chest wall defect, and the spine (T1-T10) was stabilized with bilateral titanium rods. Four separate muscle flaps were successfully used to completely cover the mesh and spinal hardware. Patient 2 had a spinal/paraspinal metastatic renal cell carcinoma that required wide excision including the adjacent paraspinal muscles and T2-T9 spinal stabilization. Reconstruction for the resulting (10 x 20 cm) defect required 4 locoregional muscle flaps and a local fasciocutaneous flap. Patient 3 underwent reconstruction following wide resection of a (13 x 3.5 cm) spinal leiomyosarcoma and unilateral spinal rod stabilization (T4-L3) with 4 local muscle flaps. Five days postoperatively, the patient required reoperation for additional (bilateral) spinal stabilization, necessitating disassembly of the existing multi-flap reconstruction and reorientation and re-inset of the existing flaps. An additional muscle flap was required to cover the additional hardware. In each of these cases, cutaneous coverage was achieved with a fasciocutaneous flap or local skin advancement. One patient had a complication: a 2 x 2 cm area of skin necrosis overlying vascularized muscle that was managed with dressing changes. The flaps used in these cases included various combinations of latissimus dorsi, trapezius, paraspinal, and serratus anterior muscle flaps and local fasciocutaneous flaps. Unresected segments of adjacent muscle were also used for flap reconstruction based on isolated segmental vascular pedicles resulting in excellent vascularity of the inset flap.

Discussion: A reliable algorithmic strategy for reconstructing massive back and trunk defects with locoregional flaps can be useful and may obviate free tissue transfer in select cases. Free flap reconstruction of these defects can be difficult because of the a relatively long distance to reliable recipient vessels, often requiring the use of vein grafts, and the frequent need for intraoperative patient repositioning. Multiple locoregional flaps have been used successfully to reconstruct these massive defects, even in the face of perioperative radiotherapy, bulky hardware, and partial resection of adjacent flap tissues. We have found that the use of 3 or more individual flaps does not increase morbidity or complication rates and reduces operative time compared to free flap procedures.

Conclusion: With proper patient selection, multiple locoregional flaps can be used safely and reliably to reconstruct large back and trunk defects with a low complication rate. In many cases, this technique offers a good alternative to a complex free tissue transfer.