From the Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School; and Gordon Center for Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School.
Plast Reconstr Surg. 2022 Jan 1;149(1):130-141. doi: 10.1097/PRS.0000000000008631.
The real-time quantification of lymphatic flow remains elusive. Efforts to provide a metric of direct lymphatic function are not clinically translatable and lack reproducibility. Early reports demonstrate the promise of immediate lymphatic reconstruction (immediate lymphovenous bypass after lymphadenectomy) to reduce the risk of lymphedema development. However, there remains a heightened need to appraise this technique in a clinically translatable large-animal model. The aim of the authors' experiment was to evaluate the role of molecular imaging in the quantification of real-time lymphatic flow after lymphadenectomy, and lymphadenectomy with lymphovenous bypass using novel fluorophores in a swine model.
A lymphadenectomy or lymphadenectomy with subsequent lymphovenous bypass was performed in 10 female swine. After subdermal fluorophore injection, near-infrared molecular imaging of blood samples was used to evaluate change in lymphatic flow after lymphadenectomy versus after lymphadenectomy with lymphovenous bypass. Continuous imaging evaluating fluorescence of the superficial epigastric vein in the torso and adjacent skin was performed throughout all experiments. Findings between modalities were correlated.
The near-infrared dye signal in central and peripheral blood samples was often difficult to separate from background and proved challenging for reliable quantification. Venous and skin near-infrared imaging demonstrated a lymphatic clearance rate decrease of 70 percent after lymphadenectomy versus a decrease by only 30 percent after lymphadenectomy with immediate lymphovenous bypass.
In this article, the authors describe a noninvasive, swine, large-animal model to quantify lymphatic clearance using skin imaging. The authors' findings were consistent with results yielded from real-time imaging of the vein. The authors believe this model may have important implications for eventual direct translation to the clinical setting.
实时量化淋巴流量仍然难以实现。提供直接淋巴功能指标的努力在临床上不可转化，且缺乏重现性。早期报告表明，在淋巴结切除术后立即进行淋巴重建（即时淋巴静脉旁路）可以降低淋巴水肿发展的风险。然而，仍然需要在临床上可转化的大动物模型中评估这种技术。作者的实验目的是评估分子成像在淋巴结切除术后和使用新型荧光染料的淋巴结切除术后即时淋巴静脉旁路后实时淋巴流量定量中的作用。
在 10 头雌性猪中进行淋巴结切除术或淋巴结切除术后行淋巴静脉旁路术。皮下注射荧光染料后，使用近红外分子成像技术评估淋巴结切除术后与淋巴结切除术后行淋巴静脉旁路术的淋巴流量变化。在所有实验过程中，对胸壁和相邻皮肤的浅表腹壁静脉的荧光进行连续成像评估。比较不同模式下的结果。
中央和外周血样本中的近红外染料信号常常难以与背景区分开来，难以进行可靠的定量。静脉和皮肤近红外成像显示，淋巴结切除术后淋巴清除率下降 70%，而淋巴结切除术后立即行淋巴静脉旁路术仅下降 30%。
本文作者描述了一种非侵入性的、猪的大动物模型，可使用皮肤成像来定量淋巴清除。作者的发现与静脉实时成像的结果一致。作者认为，这种模型可能对最终直接转化为临床环境具有重要意义。
