Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Department of Biomedical Science, Graduate school of University of Ulsan College of Medicine, Seoul, Korea.
PLoS One. 2023 May 23;18(5):e0285384. doi: 10.1371/journal.pone.0285384. eCollection 2023.
Cancer-related lymphedema (LE) is often caused by radiotherapy and surgery such as lymph node dissection (LND). Previous studies have reported that exercise is beneficial to relieve LE, but the changes in the lymphatic system following exercise are still unclear. This study aimed to examine the changes in lymphatic drainage pathways over the exercise period and beneficial effects of exercise in rats with LE. Twelve rats were randomly allocated into exercise and control groups (EG and CG; n = 6 each). To obtain LE, inguinal and popliteal LND followed by 20 Gy irradiation was performed. Treadmill exercise was 30 minutes/day, 5 days/week over the four-week period. Consecutive indocyanine green (ICG) lymphography images were collected and classified into five patterns: i) linear; ii) splash; iii) stardust; iv) diffuse, and v) none. Ankle thickness was measured weekly. Histopathological evaluation was performed to examine the skin thickness, collagen area fraction (%) and lymphatic vessel density in harvested tissue. ICG lymphography exhibited more linear and splash patterns in the EG at week 3. The difference of swelling between both groups was significantly different at week 4 (p = 0.016). Histopathologic data revealed a thinner epidermis (p = 0.041) and dermis (p = 0.002), lower collagen area fraction (%, p = 0.002), and higher lymph vessel density (p = 0.002) in the EG than the CG. In conclusion, we found that postoperative exercise can facilitate improvement in lymphatic fluid retention in the lymphedema rat model, resulting in improvement of pathological conditions in the lymphatic system.
癌症相关的淋巴水肿（LE）通常由放疗和手术引起，如淋巴结清扫术（LND）。先前的研究报告表明，运动有助于缓解 LE，但运动对淋巴系统的影响仍不清楚。本研究旨在探讨 LE 大鼠在运动期间淋巴引流途径的变化以及运动的有益作用。将 12 只大鼠随机分配到运动组（EG）和对照组（CG）（n = 6 只）。为了获得 LE，进行了腹股沟和腘窝 LND ，然后进行 20 Gy 照射。跑步机运动持续四周，每天 30 分钟，每周 5 天。连续采集吲哚菁绿（ICG）淋巴造影图像，并将其分类为五种模式：i）线性；ii）飞溅；iii）星尘；iv）弥漫，和 v）无。每周测量踝部厚度。进行组织学评估，以检查收获组织中的皮肤厚度、胶原面积分数（%）和淋巴管密度。ICG 淋巴造影在第 3 周显示 EG 中出现更多的线性和飞溅模式。第 4 周两组之间的肿胀差异具有统计学意义（p = 0.016）。组织病理学数据显示，EG 的表皮（p = 0.041）和真皮（p = 0.002）更薄，胶原面积分数（%，p = 0.002）更低，淋巴管密度（p = 0.002）更高。总之，我们发现术后运动可促进淋巴水肿大鼠模型中淋巴液潴留的改善，从而改善淋巴系统的病理状况。
