Free flap reconstruction of sarcoma defects in the setting of radiation: a ten-year experience

Wound healing after surgery for soft tissue sarcomas, and the effect of primary plastic reconstruction - A retrospective cohort study

BACKGROUND

Immediate vascularized reconstruction after sarcoma resection may reduce wound complications common in primary closure, but previous research is conflicting. The present study analysed wound complication rates and compared wound-related outcomes among immediate vascularized reconstruction with primary closure.

MATERIALS AND METHODS

Patient- and tumour characteristics were collected from patients who received primary surgery with curative intent between 2010 and 2020 at the Stockholm Sarcoma Centre. Clinical outcomes were sought in free text in medical records. The primary outcome measures were early (<30 days) wound complications. Secondary outcome measures included late (30-day to 2-year) wound complications, time to wound healing, 30-day postoperative complications according to Clavien Dindo, and health care consumption.

RESULTS

A total of 482 patients were included, of whom 69 had immediate vascularized reconstruction. Comparison of early complications for reconstructive surgery with primary closure revealed a significantly higher complication rate for the first group (59.4 % vs 29.8 %, p < 0.01). The groups had comparable health care consumption the first and second postoperative years. In-depth analyses identified BMI >25, smoking and high-grade lesions as factors with adverse effects on wound healing.

CONCLUSIONS

Sarcoma patients experience high rates of wound complications and consume considerable health care resources. Reconstructed individuals were more susceptible to such complications than were subjects with primary closure.

Hypoxia as a stimulus for tissue formation: The concept of organogenesis in microsurgically vascularized tissue engineering constructs

Axial vascularization of tissue constructs is essential to maintain an adequate blood supply for a stable regeneration of a clinically relevant tissue size. The versatility of the arterio-venous loop (AVL) has been previously shown in various small and large animal models as well as in clinical reports for bone regeneration. We have previously demonstrated the capability of the AVL to induce axial vascularization and to support the nourishment of tissue constructs in small animal models after applying high doses of ionizing radiation comparable to those applied for adjuvant radiotherapy after head and neck cancer. We hypothesize that this robust ability to induce regeneration after irradiation could be related to a state of hypoxia inside the constructs that triggers the HIF1 (hypoxia induced factor 1) - SDF1 (stromal derived factor 1) axis leading to chemotaxis of progenitor cells and induction of tissue regeneration and vascularization. We analyzed the expression of HIF1 and SDF1 via immunofluorescence in axially vascularized bone tissue engineering constructs in Lewis rats 2 and 5 weeks after local irradiation with 9Gy or 15Gy. We also analyzed the expression of various genes for osteogenic differentiation (collagen 1, RUNX, alkaline phosphatase and osteonectin) via real time PCR analysis. The expression of HIF1 and SDF1 was enhanced two weeks after irradiation with 15Gy in comparison to non-irradiated constructs. The expression of osteogenic markers was enhanced at the 5-weeks time point with significant results regarding collagen, alkaline phosphatase and osteonectin. These results indicate that the hypoxia within the AVL constructs together with an enhanced SDF1 expression probably play a role in promoting tissue differentiation. The process of tissue generation triggered by hypoxia in the vicinity of a definite vascular axis with enhanced tissue differentiation over time resembles hereby the well-known concept of organogenesis in fetal life.

Flap Reconstruction Outcome Following Surgical Resection of Soft Tissue and Bone Sarcoma in the Setting of (Neo)adjuvant Therapy: A Sarcoma Center Experience

BACKGROUND

Soft tissue and bone sarcomas are heterogeneous groups of malignant tumors. The shift in their management, with an emphasis on limb salvage, has deemed the involvement of reconstructive surgeons an integral part of their multidisciplinary treatment. We present our experience with free and pedicled flaps in the reconstruction of sarcomas at a tertiary referral university hospital and major sarcoma center.

MATERIALS AND METHODS

All patients undergoing flap reconstruction after sarcoma resection over a 5-year period have been included in the study. Patient-related data and postoperative complications were collected retrospectively, ensuring a minimum follow-up of 3 years.

RESULTS

A total of 90 patients underwent treatment with 26 free flaps and 64 pedicled flaps. Postoperative complications occurred in 37.7% of patients, and the flap failure rate was 4.4%. Diabetes, alcohol consumption and male gender were associated with increased early necrosis of the flap. Preoperative chemotherapy significantly increased the occurrence of early infection and late dehiscence, while preoperative radiotherapy was associated with a higher incidence of lymphedema. Intraoperative radiotherapy was associated with late seromas and lymphedema.

CONCLUSIONS

Reconstructive surgery with either pedicled or free flaps is reliable, but it can be demanding in the setting of sarcoma surgery. A higher complication rate is to be expected with neoadjuvant therapy and with certain comorbidities.

Use of a bovine pericardial patch angioplasty for completion of a complicated end to side anastomosis of a recipient vessel in the free flap reconstruction of a radiated wound: A case report

Soft tissue sarcomas treated by extensive surgical resection and adjuvant radiation can lead to large tissue deficits that require free flap repair. Significant radiation can further compromise vessels necessitating novel therapeutic approaches. We describe an 82-year-old man who presented with a posterior thigh sarcoma and underwent wide local tumor resection and immediate reconstruction with a microvascular free flap. Due to radiated recipient vessels, this case required bovine patch angioplasty as a conduit for end to side anastomosis. Initial resection and pathology revealed a large myxofibrosarcoma. Wide local resection and radiotherapy resulted in a large irradiated soft tissue defect of 26 x 15 x 4 cm with exposed, radiation damaged neurovascular structures, and a lack of available regional flap options. The planned free flap, a 30 x 8 cm skin island from the left latissimus dorsi muscle with end-to-side anastomosis to the popliteal artery was complicated by friability of the vessel wall and insufficient perfusion. Given the extent of resection and radiation, there were no alternative recipient vessels present within the field. A bovine pericardial patch angioplasty of 2.5 cm in length was performed to the diseased popliteal vessel and an end to side anastomosis was successfully performed between the thoracodorsal artery and the patch. Improved reperfusion of the free flap was noted immediately following anastomosis indicating completion of the anastomosis of our complicated recipient vessel. During the uncomplicated postoperative course, the flap had good perfusion with Doppler signals present, and incision sites intact at discharge from acute hospitalization. Recurrent sarcomas that have undergone extensive resection and radiotherapy pose significant reconstructive challenges. For defects that require free tissue reconstruction when there are limited options for healthy, recipient vessels, bovine pericardial patch angioplasty may act as a robust conduit for diseased vessels.

Practical Strategies in Reconstruction of Soft-Tissue Sarcoma

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Discuss the natural history and pathophysiology of sarcoma. 2. Summarize the most up-to-date multidisciplinary management of soft-tissue sarcoma. 3. Provide a synopsis of reconstructive modalities based on anatomical location. 4. Highlight some novel strategies for treatment of lymphedema and phantom limb pain that are common sequelae following treatment and resection of soft-tissue sarcomas.

SUMMARY

The management of soft-tissue sarcoma presents unique challenges to the reconstructive surgeon. The optimal management mandates a multidisciplinary approach; however, reconstruction must take into account the extent of the resection and exposed vital structures, but often occurs in the setting of adjuvant treatments including chemotherapy and radiation therapy. Reconstruction is based on the extent of the defect and the location of the primary tumor. As such, an evidence-based, algorithmic approach following the reconstructive ladder is warranted to minimize the risks of complications and maximize success, which varies from head and neck to torso to breast to extremity sarcomas. Aside from reconstruction of the defect, advances in the surgical treatment of lymphedema and neuropathic pain resulting from treatment and extirpation of soft-tissue sarcoma are critical to maintain function and patients' quality of life.

Fifty years of bone tumors

There have been enormous advances in the treatment of bone tumors over the past half-century. The most notable of these has been the transition from amputation as the standard of care to limb salvage surgery. This transition is the result of advances in imaging techniques, accurate diagnosis, systemic therapies (including chemotherapy), and prosthetic design for the reconstruction of musculoskeletal defects. Advances have also been made in the management of benign and metastatic bone tumors.