LAUSR

The standard of care in extremity soft tissue sarcoma is multimodal therapy with surgery, radiation, and chemotherapy to achieve optimal outcomes [1]. Sarcomas often abut/infiltrate/encase major neurovascular structures. Surgery may entail resection structures or amputation with their attendant morbidity. Treatment strategies for these patients may include neoadjuvant therapy, resection, and reconstruction of nerves/vessels [2, 3]. Kawaguchi et al. [4] described the concept of qualitative margin assessment and classified anatomic structures into thin, thick, and very thick barriers for tumor spread. In this system, the epineurium and outer vessel sheath are equivalent to a 2-cm margin. The epineurium acts as a barrier and may prevent infiltration even when sarcomas surround and encase nerves. Matsumoto et al. [5] described the procedure of in situ preparation to prevent unnecessary resection of nerves/vessels in such patients. This is an intraoperative technique to (a) prepare the vessels and nerves, (b) evaluate the surgical margin, and (c) preserve the nerves/vessels if the surgical margin is uninvolved. In this paper, we attempt to explain patient selection and describe the surgical technique of in situ preparation. Surgical Technique