Nerve autofluorescence in near-ultraviolet light markedly enhances nerve visualization in vivo.

BACKGROUND: During surgery, surgeons must accurately localize nerves to avoid injuring them. Recently, we have discovered that nerves fluoresce in near-ultraviolet light (NUV) light. The aims of the current study were to determine the extent to which nerves fluoresce more brightly than background and vascular structures in NUV light, and identify the NUV intensity at which nerves are most distinguishable from other tissues. METHODS: We exposed sciatic nerves within the posterior thigh in five 250-300 gm Wistar rats, then observed them at four different NUV intensity levels: 20%, 35%, 50%, and 100%. Brightness of fluorescence was measured by fluorescence spectroscopy, quantified as a fluorescence score using Image-J software, and statistically compared between nerves, background, and both an artery and vein by unpaired Student's t tests with Bonferroni adjustment to accommodate multiple comparisons. Sensitivity, specificity, and accuracy were calculated for each NUV intensity. RESULTS: At 20, 35, 50, and 100% NUV intensity, fluorescence scores for nerves versus background tissues were 117.4 versus 40.0, 225.8 versus 88.0, 250.6 versus 121.4, and 252.8 versus 169.4, respectively (all p < 0.001). Fluorescence scores plateaued at 50% NUV intensity for nerves, but continued to rise for background. At 35%, 50%, and 100% NUV intensity, a fluorescence score of 200 was 100% sensitive, specific, and accurate identifying nerves. At 100 NUV intensity, artery and vein scores were 61.8 and 60.0, both dramatically lower than for nerves (p < 0.001). CONCLUSIONS: At all NUV intensities ≥ 35%, a fluorescence score of 200 is 100% accurate distinguishing nerves from other anatomical structures in vivo.

Resultados del tratamiento quirúrgico de sarcomas de partes blandas en adultos / Outcomes of surgical treatment of soft-tissue sarcomas in adults

Antecedentes: los sarcomas de partes blandas son raros tumores mesenquimáticos con varios tipos histológicos y diferentes comportamientos clínicos. Objetivo: describir las características clínicas y patológicas, así como los resultados del tratamiento quirúrgico de una serie de pacientes operados por sarcomas de partes blandas. Material y métodos: se realizó una revisión retrospectiva de las historias clínicas de 2403 pacientes operados entre octubre de 2014 y abril de 2018. Veintidós de ellos (0,91%) presentaron sarcomas de partes blandas. Resultados: el promedio de edad fue 52 años (rango 19-92), 13 (59%) eran mujeres. La localización de los tumores fue: miembro inferior en 12 casos, cabeza y cuello en 5, tronco en 3 y miembro superior en 2. Catorce casos (63,6%) fueron tumores de alto grado. Los tipos patológicos fueron: sarcoma pleomórfico 7 (32%), sarcoma sinovial 4 (18%), liposarcoma 3 (14%), otros 4 (36 %). Todos fueron extirpados en forma completa y en 5 casos (35,7%) requirieron amputación: 4 de miembro inferior y uno superior. Según el tamaño y la ubicación del tumor se emplearon diferentes procedimientos reconstructivos, incluyendo 3 colgajos libres. Aquellos pacientes con lesiones de alto grado o con márgenes histológicamente positivos recibieron radioterapia posoperatoria. Durante el seguimiento (promedio 16 meses), seis pacientes presentaron recidivas locales, cuatro con metástasis pulmonares sincrónicas, todos ellos con tumores de alto grado. La sobrevida global fue del 86,4%. Conclusión: los sarcomas de partes blandas son neoplasias infrecuentes e invasivas, ampliamente distribuidas, que requieren procedimientos quirúrgicos agresivos. Es necesario tratamiento adyuvante en casos seleccionados y seguimiento periódico debido a la alta tasa de recidiva y metástasis a distancia.

Background: Soft-tissue sarcomas (STS) are rare mesenchymal tumors with several histologic subtypes and different clinical patterns. Objective: The aim of this study was to describe the clinical and pathological characteristics and surgical outcomes of a series of patients with STS. Material and methods: The clinical records of 2403 undergoing surgery between October 2014 and April 2018 were retrospectively reviewed. Twenty-two patients (0.91%) presented STS. Results: Mean age was 52 years (range: 19-92) and 13 (59%) were women. The tumors were located in the lower extremities in 12 cases, head and neck in five, trunk in three and upper extremities in two. Fourteen cases (63.6%) were high-grade tumors. Pleomorphic sarcoma was the most common histologic type (32%) followed by synovial sarcoma (18%), liposarcoma (14%), and other types (36%). All the tumors were completely resected and five patients (35.7%) required amputation, four in the lower extremity and on in the upper extremity. Different reconstructive procedures were performed according to tumor size and location, including three free flaps. Those patients with high-grade sarcomas or with positive margins received postoperative radiotherapy. After a mean follow-up of 16 months, six patients presented local recurrences and four patients had synchronous metastatic disease in the lungs; all these patients had high-grade tumors. Overall survival was 86.4%. Conclusion: STS are rare and invasive neoplasms, widely distributed, requiring aggressive and occasionally complex surgical procedures. It is necessary to consider adjuvant treatments in selected cases and to maintain regular follow-up due to the high rate of recurrences and distant metastases.