Introduction

Response to anticoagulation varies during management of acute hospitalized pulmonary embolism. We aimed to study thrombus histology in pulmonary embolism samples removed during acute surgical embolectomy to evaluate whether thrombus morphology was similar between patients and whether there was an association with duration of symptoms and/or resolution on follow up imaging.

Methods

This was a retrospective observational single center study at the University of Rochester Medical Center. We evaluated patients that underwent acute surgical embolectomy and followed up in our clinic 2 – 4 months after the event with Ventilation/Perfusion (V/Q) scan obtained for all regardless of symptoms. Thromboemboli were formalin fixed and processed for light microscopy in the hospital histopathology laboratory. Four-micron thick sections were stained with hematoxylin and eosin, Masson trichrome, and Verhoeff elastic tissue stains. Immunohistochemistry was performed using anti-CD31 and anti-CD68. Slides were independently evaluated for time-dependent microscopic changes using Irniger's classification by two blinded pathologists.

Results

Sixteen patients underwent embolectomy with fifteen having V/Q imaging at follow up. The majority of patients were female. Samples showed a generally similar overall architecture that included a central core composed primarily of red blood cells and fibrin and an outer layer of platelets and monocytes. Two samples had evidence of fibrosis and recanalization.

Conclusions

We found heterogeneous histopathology in samples obtained during acute embolectomy. Further prospective studies should systematically characterize clot morphology and evaluate treatment response and outcomes. Careful thrombus specimen measurement and consistent sampling for sections will be required to draw firm conclusions.

中文翻译：

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未开发的资源：从中度或高危肺栓塞患者中恢复的血栓特征

介绍

急性住院肺栓塞治疗期间对抗凝的反应各不相同。我们旨在研究在急性手术取栓期间取出的肺栓塞样本中的血栓组织学，以评估患者之间的血栓形态是否相似，以及是否与症状持续时间和/或随访影像学分辨率有关。

方法

这是罗切斯特大学医学中心的一项回顾性观察性单中心研究。我们评估了接受急性手术取栓术的患者，并在事件发生后 2-4 个月在我们的诊所进行了随访，无论症状如何，所有患者都获得了通气/灌注 (V/Q) 扫描。血栓栓塞经福尔马林固定并在医院组织病理学实验室进行光学显微镜检查。用苏木精和伊红、Masson 三色和 Verhoeff 弹性组织染色剂对四微米厚的切片进行染色。使用抗CD31和抗CD68进行免疫组织化学。由两名盲法病理学家使用 Irniger 分类独立评估载玻片的时间依赖性微观变化。

结果

16 名患者接受了栓子切除术，其中 15 名患者在随访时进行了 V/Q 成像。大多数患者为女性。样品显示出大致相似的整体结构，包括主要由红细胞和纤维蛋白组成的中央核心以及血小板和单核细胞的外层。两个样本有纤维化和再通的证据。

结论

我们在急性取栓期间获得的样本中发现了异质组织病理学。进一步的前瞻性研究应系统地描述凝块形态并评估治疗反应和结果。需要仔细的血栓标本测量和切片的一致采样才能得出可靠的结论。