Department of Vascular and Endovascular Surgery, Gabriel Montpied Hospital, University Hospital of Clermont-Ferrand, Clermont-Ferrand, France.
Department of Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; Heart and Vascular Research Institute, Harry Perkins Medical Research Institute, Perth, Western Australia, Australia.
J Vasc Surg Venous Lymphat Disord. 2024 Jul;12(4):101895. doi: 10.1016/j.jvsv.2024.101895. Epub 2024 Apr 26.
Iliocaval thrombotic obstruction is a challenging condition, especially because thrombus age and corresponding pathological remodeling at presentation are unknown, which directly impacts management. Our aim was to assess the ability of magnetic resonance imaging (MRI) in determining age thresholds of experimentally created inferior vena cava (IVC) thrombosis in pigs.
We used a previously described swine model of IVC thrombosis. The animals underwent MRI at baseline, immediately after thrombosis creation, and after a follow-up period extending from 2 to 28 days. Thirteen pigs were divided into three groups according to disease chronicity: acute group (AG; n = 5), subacute group (SAG; n = 4), and chronic group (CG; n = 4), with a mean thrombosis age of 6.4 ± 2.5 days, 15.7 ± 2.8 days, and 28 ± 5.7 days, respectively. A T-weighted volumetric interpolated breath-hold examination sequence was used to anatomically delineate IVC thrombus as a region of interest. Three other MRI sequences were used to assess the thrombus signal.
The Kruskal-Wallis test showed a statistically significant difference in T relaxation times after contrast injection (P = .026) between the three groups of chronicity. The AG (360.2 ± 102.5 ms) was significantly different from the CG (336.7 ± 55.2 ms; P = .003), and the SAG (354.1 ± 89.7 ms) was significantly different from the AG (P = .027). There was a statistically significant difference in native T relaxation times (P = .038) between the three groups. The AG (160 ± 86.7 ms) was significantly different from the SAG (142.3 ± 55.4 ms; P = .027), and the SAG was significantly different from the CG (178.4 ± 11.7 ms; P = .004).
This study highlighted MRI characteristics in a swine model that might have the potential to significantly differentiate subacute and chronic stages from an acute stage of deep vein thrombosis in humans. Further clinical studies in humans are warranted.
In addition to providing a better understanding of venous thrombosis remodeling over time, magnetic resonance imaging has the potential to be a tool that could allow us to characterize the composition of venous thrombus over an interval, allowing for a refined analysis of the local evolution of venous thrombosis. We propose a noninvasive and innovative method to characterize different thresholds of chronicity with magnetic resonance imaging features of central deep vein thrombosis of the inferior vena cava experimentally obtained using a totally endovascular in vivo swine model, mimicking human pathophysiology. Being able to determine these features noninvasively is critical for vascular specialists when it comes to choosing between fibrinolytic therapy, percutaneous thrombectomy, or surgical management.
髂静脉血栓形成是一种具有挑战性的疾病，特别是因为血栓的年龄和相应的病理重塑在发病时是未知的，这直接影响到治疗方案的选择。我们的目的是评估磁共振成像（MRI）在确定猪实验性下腔静脉（IVC）血栓形成年龄阈值方面的能力。
我们使用了先前描述的 IVC 血栓形成猪模型。动物在基线、血栓形成后即刻以及从 2 天到 28 天的随访期后进行 MRI 检查。13 只猪根据疾病的慢性程度分为三组：急性组（AG；n=5）、亚急性组（SAG；n=4）和慢性组（CG；n=4），血栓形成的平均年龄分别为 6.4±2.5 天、15.7±2.8 天和 28±5.7 天。使用 T 加权容积内插屏气检查序列将 IVC 血栓作为感兴趣区进行解剖描绘。另外使用了三种其他 MRI 序列来评估血栓的信号。
Kruskal-Wallis 检验显示三组慢性程度之间的 T1 弛豫时间在对比剂注射后有统计学上的显著差异（P=0.026）。AG（360.2±102.5 ms）与 CG（336.7±55.2 ms；P=0.003）之间有显著差异，SAG（354.1±89.7 ms）与 AG（P=0.027）之间也有显著差异。三组之间的 T1 弛豫时间有统计学上的显著差异（P=0.038）。AG（160±86.7 ms）与 SAG（142.3±55.4 ms；P=0.027）之间有显著差异，SAG 与 CG（178.4±11.7 ms；P=0.004）之间也有显著差异。
本研究强调了 MRI 特征在猪模型中的表现，这些特征可能具有显著区分人类深静脉血栓形成的亚急性和慢性阶段与急性阶段的潜力。需要在人类中进行进一步的临床研究。
除了提供对静脉血栓形成随时间重塑的更好理解外，磁共振成像还有可能成为一种工具，可以帮助我们在一段时间内对静脉血栓的组成进行特征描述，从而对静脉血栓的局部演变进行更精细的分析。我们提出了一种非侵入性和创新性的方法，使用完全血管内体内猪模型，模拟人体生理学，对实验性下腔静脉中心深静脉血栓形成的不同慢性程度的 MRI 特征进行特征描述。当涉及到选择纤维蛋白溶解治疗、经皮血栓切除术还是手术治疗时，血管专家能够无创地确定这些特征是至关重要的。
