Pulmonary artery dissection and rupture in a patient with idiopathic pulmonary artery hypertension.
Pulmonary artery dissection and rupture in a patient with idiopathic pulmonary artery hypertension.
复制标题
特发性肺动脉高压患者的肺动脉夹层和破裂。
DOI：
10.1164/rccm.201304-0693im
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发表时间：
2014
影响因子：
24.7
通讯作者：
Sadikot,RuxanaT
中科院分区：
文献类型：
--
作者：
Patel,Vipul;Mehta,HirenJ;Sadikot,RuxanaT
一位78岁女性特发性肺动脉高压(PAH)患者在接受波生坦、西地那非和曲普替尼的治疗后，因房颤和心室率过快而入院。CT肺血管造影(CTPA)显示肺动脉(PA)增大，无肺血栓形成。在过去的6个月中，PA直径显著增大(图1)。患者在没有任何可识别的病因的情况下，对PAH的次要原因进行了广泛的评估。两年前右心导管术显示PA压为12 2/42 mm Hg，平均69 mm Hg，肺动脉阻断压为11 mm Hg，心输出量为3 4 L/min。在过去的8年中，患者的PA压力没有任何明显的变化。在住院期间，她突然心跳骤停。尸检显示心包积血，主动脉夹层破裂(图2)，内膜分离(图3)。详细的大体和组织学检查显示PA中层肥大，有夹层迹象，并有愈合的迹象(图4)。PA中层弹力纤维受损。肺实质的组织学检查没有发现血管炎或其他已知与PA动脉瘤相关的原因的证据。PAH很少引起PA剥离，导致血管破裂。动脉破裂通常表现为心源性休克或猝死，并在死后被诊断。大多数PA夹层发生在慢性肺动脉高压引起的内侧退行性变、弹性纤维断裂和广泛的肺动脉树扩张的情况下(2)。拉普拉斯定律将顶壁张力描述为取决于压力和血管直径(3)。在PAH患者中，肺血管扩张但心功能保持不变，在用力过程中肺压力增加可能会导致壁壁张力增加，从而导致内膜撕裂。PA夹层中的假腔倾向于破裂，而不是像主动脉夹层中常见的那样形成折返处，导致心包填塞和随后的死亡，如所描述的病例。在6个月的时间里，我们的患者在CTPA上发现PA直径迅速增大。这是否是即将破裂和解剖的预兆，目前尚无定论。虽然在PAH之后通常不进行连续的CT扫描，但这一病例表明，直径的快速改变应该通过三维CT或磁共振血管成像进行进一步的评估，以排除灾难性事件。目前还没有明确的报告表明外科干预在快速扩张的PA的管理中的作用，以防止剥离。这个病例说明，在特定的病例中，通过某种形式的成像监测PA直径可能会提供预后线索。
A 78-year-old woman with idiopathic pulmonary arterial hypertension (PAH) who was on treatment with bosentan, sildenafil, and trepostinil was admitted with atrial fibrillation with rapid ventricular rate. Computed tomography (CT) pulmonary angiography (CTPA) showed an enlarged pulmonary artery (PA) without any pulmonary embolism. The PA diameter had significantly increased over the past 6 months (Figure 1). The patient had extensive evaluation for secondary causes of PAH without any identifiable etiology. Two years before, right heart catheterization showed a PA pressure of 122/42 mm Hg with a mean of 69 mm Hg, pulmonary artery occlusion pressure was 11 mm Hg, and the cardiac output was 3.4 L/min. The patient did not have any significant change in PA pressure over the preceding 8 years. During this hospitalization, she succumbed to a sudden asystolic cardiopulmonary arrest. Her autopsy showed hemo-pericardium with dissection and rupture of the main PA (Figure 2) with separation of the intimal surface (Figure 3). Detailed gross and histologic examination showed hypertrophy of tunica media of the PA and signs of prior dissections with some evidence of healing (Figure 4). Tunica media of PA showed damage to elastic fibers. Histology of lung parenchyma showed no evidence of vasculitis or other causes known to be associated with PA aneurysm. PAH rarely causes dissection of the PA leading to rupture of vessel. PA rupture usually manifests as cardiogenic shock or sudden death, and is diagnosed postmortem (1). The majority of PA dissections occur in the presence of medial degeneration with fragmentation of elastic fibers and generalized dilatation of the pulmonary arterial tree caused by chronic pulmonary hypertension (2). Laplace’s law describes parietal wall tension as being dependent on the pressure and diameter of the vessel (3). In patients with PAH who have dilated pulmonary vessels with preserved cardiac function, the increase of pulmonary pressure during exertion may cause an increase in parietal wall tension that could lead to development of an intimal tear. The false lumen in PA dissection tends to rupture rather than develop a reentry site as is usual in aortic dissection, resulting in pericardial tamponade (4) and subsequent death as in the case described. Our patient had a rapid increase in PA diameter noted on CTPA over a period of 6 months. Whether this was a harbinger of an impending rupture and dissection is a matter of speculation. Although PAH is routinely not followed by serial CT scan (5), this case suggests that a rapid change in diameter should warrant further evaluation by imaging with three-dimensional CT or magnetic resonance angiogram to exclude a catastrophic event. There are no definitive reports to indicate a role for surgical intervention for management of rapidly expanding PA to prevent a dissection. This case illustrates that in select cases, monitoring PA diameter by some form of imaging may provide prognostic clues.■