Relationship of the number and size of superficial groin lymph nodes with the stage of secondary lymphatic edema

PURPOSE: This study evaluated the relationships of the size and number of superficial groin lymph nodes with the lower limb lymphedema stage and thus examined the role of superficial lymphatic lymph nodes in secondary lymphedema development. METHODS: We determined the number and size of superficial groin lymph nodes using horizontal plane computed tomography (CT) and the lymphedema stage in the lower limbs of 25 patients with gynecologic cancer. RESULTS: The patients had an average of 2.92 (range, 1-7) superficial groin lymph nodes; the mean size of the 146 evaluated lymph nodes was 7.55 mm (range, 5-15 mm). In 19 of 25 patients (76%), the side with major edema contained fewer superficial groin lymph nodes. In total, 22 patients (88%) had fewer superficial groin lymph nodes or a smaller total lymph node size on the edematous dominant side. CONCLUSIONS: In this evaluation of the link between superficial groin lymph node laterality and secondary lymphedema staging, we found that patients with large lymph node numbers and sizes tended to present with a relatively earlier stage of lymphedema. Our results therefore suggest that the size and number of superficial groin lymph nodes affect the lymphedema stage

A Novel Lymphaticovenular Anastomosis Rat Model

INTRODUCTION:　 Lymphaticovenular anastomosis (LVA) has become an important procedure for the surgical treatment of lymphedema. In the past, the anatomy of the lymphatic system of animal models has been reported. However, to our knowledge, there have been few reports of animal models of LVA including training model. In this study, we report on a relatively simple and ideal animal LVA model based on peritoneal lymph ducts and veins.　 PATIENTS AND METHODS:　 For 10 rats, diameters of lumbar lymphatic ducts and iliolumbar veins in the peritoneal cavity on both sides were measured, and LVA was performed. In addition, we measured the diameters of 28 lymphatic ducts and veins in 8 patients who had previously undergone LVA and compared the results with those obtained in this rat model.　 RESULTS:　 The mean diameter of the lymphatic ducts was 0.61 mm, and the iliolumbar veins were 0.81 mm. On the other hand, the mean diameters of the 28 lymphatic ducts and veins of the 8 patients in whom we performed LVA were 0.58 and 0.76 mm, respectively. The differences in the diameters of the lymph vessels and veins between the rats and patients were not statistically significant.　 CONCLUSIONS:　 We report on an LVA model involving the use of the lumbar lymphatic duct and iliolumbar veins of rats. The diameter, nature, and placement of the anastomosis using this model are very similar to that noted during real human surgery. We believe that our rat model will be useful as a practical training model for LVA and in studies on postoperative changes in LVA

Histologic Evaluation of Lymphaticovenular Anastomosis Outcomes in the Rat Experimental Model: Comparison of Cases with Patency and Obstruction

BACKGROUND: Lymphaticovenular anastomosis plays an important role in the surgical treatment of lymphedema. The outcomes of lymphaticovenular anastomosis are evaluated based on changes in edema; however, isolated assessment of the anastomosis itself is difficult. The authors used an animal experimental model to conduct a detailed examination of histologic changes associated with lymphaticovenular anastomosis and determined the factors important for success. METHODS: The experimental lymphaticovenular anastomosis model was created using lumbar lymph ducts and iliolumbar veins of Wistar rats. The authors performed anastomosis under a microscope and reviewed postoperative histologic changes using optical and electron microscopy. In addition, electron microscopy and histology were used for detailed examination of the area in the vicinity of the anastomotic region in cases with patency and obstruction. RESULTS: The patency rates immediately after, 1 week after, and 1 month after lymphaticovenular anastomosis were 100 percent (20 of 20), 70 percent (14 of 20), and 65 percent, respectively. A detailed examination of the anastomotic region with electron microscopy revealed that, in cases with patency, there was no notable transformation of the endothelial cells, which formed a smooth layer. In contrast, in obstruction cases, the corresponding region of the endothelium was irregular in structure. CONCLUSIONS: Vessel obstruction after lymphaticovenular anastomosis may be associated with irregular arrangement of the endothelial layer, leading to exposure of subendothelial tissues and platelet formation. One part of the postoperative changes after anastomosis and a cause of obstruction were elucidated in this study. The authors' results may enable improvements in lymphaticovenular anastomosis by translating back to real clinical operations