Objective

Although the development of lymphatic collaterals is expected following lymphedema, little is known about the anatomic details of such compensatory pathways or their association with symptoms. Magnetic resonance lymphangiography (MRL) has been shown to be superior to lymphoscintigraphy and indocyanine green lymphography in visualizing lymphatics. This study aimed to analyze MRL images of lower limbs to elucidate the patterns of lymphatic collateral formation and their association with the clinical stages of lymphedema.

Methods

We enrolled 56 consecutive patients (112 lower limbs) with lymphedema who underwent MRL. Two radiologists performed a consensus reading of MRL images for the presence or absence of collateral lymphatic pathways, and the results were compared with the clinical stages. Furthermore, the frequency of abnormal MRL findings in 43 asymptomatic lower limbs of patients with unilateral lymphedema was analyzed and compared with that in the 69 symptomatic lower limbs of the patients. The imaging findings were also compared with the cause of lymphedema.

Results

All three collateral pathways (anterolateral, deep, and posteromedial lymphatics) were visualized at a higher (P < .05) frequency in stage II than in stage 0 lower limbs. The frequency of visualization of the three collaterals was significantly higher in symptomatic (stages I-III) lower limbs than in asymptomatic (stage 0) lower limbs. Most (76.8%) of the symptomatic limbs exhibited at least one of these collaterals, and the frequency was significantly higher than in the asymptomatic limbs (P < .001). Most (81.4%) of the asymptomatic (stage 0) lower limbs had at least one abnormal finding in terms of lymphatic circulation, although this proportion was significantly lower compared with the symptomatic limbs (98.6%). The collaterals tended to appear less frequently in primary lymphedema than in secondary lymphedema, reaching statistical significance in the posteromedial lymphatics.

Conclusions

These results suggested that the two superficial lymphatic groups and the deep lymphatic system act as major collaterals of the lower limbs in patients with lymphedema. Furthermore, MRL of most patients with unilateral lymphedema demonstrated abnormal findings, including collateral formation, not only in the affected lower limb but also in the asymptomatic lower limb. In primary lymphedema, the collaterals may appear less frequently than in secondary lymphedema. Collaterals should be taken into consideration in planning the site of lymphaticovenous anastomosis and assessing disease progression. MRL can visualize preclinical alterations in lymphatic flow and compensatory pathways; therefore, we expect that it will be useful for the early diagnosis of lymphedema.

中文翻译：

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磁共振淋巴血管造影分析下肢淋巴水肿患者的侧支淋巴循环

客观的

尽管预计在淋巴水肿后会出现淋巴侧支，但对这种代偿途径的解剖学细节或它们与症状的关系知之甚少。磁共振淋巴管造影（MRL）在可视化淋巴管造影方面优于淋巴闪烁显像和吲哚菁绿淋巴造影。本研究旨在分析下肢的MRL图像，以阐明淋巴侧支形成的模式及其与淋巴水肿临床分期的关系。

方法

我们招募了56例接受MRL的连续性淋巴水肿患者（下肢112例）。两位放射线医师对MRL图像是否存在侧支淋巴途径进行了共识读取，并将结果与​​临床阶段进行了比较。此外，分析了43例单侧淋巴水肿无症状下肢患者的MRL异常发现频率，并将其与69例有症状下肢患者的MRL结果进行比较。影像学检查结果也与淋巴水肿的原因进行了比较。

结果

在第三阶段，所有三个侧支通路（前外侧，深部和后内侧淋巴管）的可视化 频率均高于（0级）下肢（P <.05）。有症状的下肢（I-III期）的三个侧支的可视化频率显着高于无症状的下肢（0期）。多数（76.8％）有症状的肢体表现出至少其中的一种侧支，其频率显着高于无症状肢体（P <.001）。在无症状（0级）下肢中，大多数（81.4％）在淋巴循环方面至少有一个异常发现，尽管与有症状的肢体（98.6％）相比，这一比例要低得多。侧支在原发性淋巴水肿中的出现频率往往少于继发性淋巴水肿，在后内侧淋巴管中达到统计学意义。

结论

这些结果表明，两个浅表淋巴组和深部淋巴系统是淋巴水肿患者下肢的主要侧支。此外，大多数单侧淋巴水肿患者的MRL不仅在受影响的下肢而且在无症状的下肢中均表现出异常的发现，包括侧支形成。与原发性淋巴水肿相比，原发性淋巴水肿的侧支出现频率更低。在计划淋巴管静脉吻合术的部位和评估疾病进展时，应考虑到附带因素。MRL可以可视化临床前淋巴流量和代偿途径的改变；因此，我们希望它将对淋巴水肿的早期诊断有用。