BACKGROUND The Fontan procedure has revolutionized the treatment of univentricular hearts. However, it is associated with severe complications such as protein-losing enteropathy, plastic bronchitis, and peripheral edema that may involve the lymphatic circulation. We aimed to assess lymphatic function and morphology in patients with a univentricular circulation. METHODS The functional state of lymphatic vessels in the lower extremities of patients with a Fontan circulation (n=10) was investigated using the novel technique near-infrared fluorescence imaging and compared with an age-, sex-, and weight-matched control group of healthy volunteers (n=10). The lymphatic morphology was described using T2-weighted magnetic resonance imaging, and microvascular permeability was estimated by strain gauge plethysmography. RESULTS The Fontan patients had 17% lower lymphatic pumping pressure (50±3.1 mm Hg) compared with controls (60±2.8 mm Hg; P=0.0341) and a 62% higher contraction frequency (0.8±0.1 min-1) compared with the healthy controls (0.5±0.1 min-1; P=0.0432). Velocity by which the lymph is moved and refill time after manual emptying of the lymphatic vessels showed no differences between the 2 groups. The thoracic duct was elongated 10% ( P=0.0409) and with an abnormal course in the Fontan patients compared with normal. No difference in microvascular permeability was found between the 2 groups. CONCLUSIONS Patients with a Fontan circulation have an impaired lymphatic pumping capacity and morphologically changed thoracic duct. Our results indicate a challenged lymphatic vasculature in the Fontan circulation and may play a role in the pathogenesis of the complications that are seen in Fontan patients. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov . Unique identifier: NCT03379805.

中文翻译：

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Fontan循环患者的淋巴管的形态和功能。

背景技术Fontan手术已经彻底改变了单心室心脏的治疗。但是，它伴随着严重的并发症，例如蛋白质丢失性肠病，可塑性支气管炎和可能涉及淋巴循环的外周水肿。我们旨在评估单室循环患者的淋巴功能和形态。方法使用新型技术近红外荧光成像技术研究Fontan循环（n = 10）患者下肢淋巴管的功能状态，并与年龄，性别和体重匹配的对照组进行比较。健康的志愿者（n = 10）。使用T2加权磁共振成像描述淋巴形态，并通过应变仪体积描记法评估微血管通透性。结果Fontan患者的淋巴泵压（50±3.1 mm Hg）比对照组（60±2.8 mm Hg； P = 0.0341）低17％，收缩频率（0.8±0.1 min-1）比对照组低62％。健康对照（0.5±0.1 min-1; P = 0.0432）。手动排空淋巴管后淋巴移动的速度和补充时间显示两组之间没有差异。与正常人相比，丰坦患者的胸导管延长了10％（P = 0.0409），并且病程异常。两组之间的微血管通透性没有差异。结论Fontan循环患者淋巴泵能力受损，胸导管形态发生改变。我们的结果表明，在Fontan循环中淋巴管系统受到挑战，并可能在Fontan患者中发现的并发症的发病机理中发挥作用。临床试验注册网址：https://www.clinicaltrials.gov。唯一标识符：NCT03379805。