Chronic pulmonary embolism and pulmonary hypertension

Incomplete resolution of acute pulmonary embolism (PE) is frequently observed after acute PE and may rarely result in chronic thromboembolic pulmonary hypertension (CTEPH). The underlying pathophysiological mechanism is largely unknown. Evidence underlines the concept of a dual pulmonary vascular compartment model consisting of increased pulmonary vascular resistance by both large vessel obstruction and distal small vessel obliteration, the latter initiated by pathological vascular remodeling. Up to 40% of patients with established CTEPH have no prior history of symptomatic venous thromboembolism. CTEPH is associated with a poor prognosis if left untreated. Therefore, the diagnostic approach of CTEPH aims at assessing the location and extent of the embolic obstruction, establishing the operability and prognosis of the patients and ruling out other variations of pulmonary hypertension with distinct indicated treatment. Heart catheterization for invasive pressure measurements and pulmonary catheter angiography is obligatory for the final diagnosis. Pulmonary thromboendarterectomy is the treatment of choice. In certain patients with persistent or recurrent pulmonary hypertension after surgery or with inoperable disease, pharmacotherapy might be beneficial.     

肺动脉血栓内膜剥脱术后再灌注肺水肿的进展

肺血栓栓塞症是一种常见、多发且病死率和致残率高的疾病。大多数急性肺动脉血栓栓塞经及时的溶栓抗凝等治疗和 (或 )自身的纤溶系统能将血栓不同程度地溶解 ,另有0 1%～ 0 2 %的患者因血栓在急性期未能溶解或栓塞反复发生进而发展成慢性栓塞性肺动脉高压。慢性栓塞性肺动脉高压溶栓无效 ,抗凝、扩血管治疗效果不佳 ,其病理过程多呈进行性加重或稳定一段时间后再次加重 ,自然预后差。肺动脉平均压 >3 0ｍｍＨｇ(1ｍｍＨｇ =0 13 3ｋＰａ)的慢性栓塞性肺动脉高压患者 5年生存率为 3 0 % ,肺动脉平均压 >5 0ｍｍＨｇ者仅为 10 %。肺动脉血…     

Retrograde pulmonary perfusion improves results in pulmonary embolectomy for massive pulmonary embolism

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, they still range from 30% to 45% when the surgery is performed on critically ill patients, and the rates reach 60% in patients who have experienced cardiac arrest before the procedure. The causes of death in these patients are generally attributed to right heart failure due to persistent pulmonary hypertension, intractable pulmonary edema, and massive parenchymal and intrabronchial hemorrhage. Clinical and experimental findings indicate that venous air embolism causes severe or even lethal damage to the pulmonary microvasculature and the lung parenchyma consequent to the release of endothelium-derived cytokines. These findings are similar to those observed when severely compromised patients undergo pulmonary embolectomy-air entrapped in the pulmonary artery during embolectomy can lead to fatal outcomes.Besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, retrograde pulmonary perfusion fills the pulmonary artery with blood and prevents pulmonary air embolism. In this retrospective study, we analyzed a series of 21 consecutive critically ill patients in whom we applied retrograde pulmonary perfusion while performing standard pulmonary embolectomy. No patient died or experienced major postoperative complications. We believe that the use of retrograde pulmonary perfusion decreases morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.     

Cavitating pulmonary infarcts revealing thromboembolic pulmonary hypertension

Several etiologies are involved in the pathogenesis of cavitating pulmonary disease including neoplastic, infectious or inflammatory processes. Another is pulmonary infarction associated with venous thromboembolism. The lung cavities tend to be located peripherally and are the result of pulmonary embolism. We report the case of a woman with chronic thromboembolic pulmonary hypertension (CTEPH), associated with familial thrombophilia, revealed by cavitating pulmonary infarcts. CTEPH is sometimes diagnosed during an episode of recurrent pulmonary embolism following previously unnoticed lesions. Thrombophilias such as isolated elevated factor VIII are risk factors for CTEPH.     

Chronic solitary pulmonary nodule due to unsuspected pulmonary infarction from silent pulmonary embolism

Abstract A case of pulmonary embolism showing a longstanding solitary pulmonary nodule is presented. An asymptomatic 57 year-old man with a solitary nodule in the right lower lobe was referred to our hospital. A pulmonary perfusion-ventilation scan following a sudden onset of dyspnoea established the diagnosis of recurrent pulmonary embolism. The nodule gradually disappeared after anticoagulant treatment, indicating that the nodule was pulmonary infarction from silent pulmonary embolism. Although the incidence of pulmonary infarction is low in Japan, this case suggests that pulmonary infarction from silent pulmonary embolism should be considered as one important cause of a solitary pulmonary nodule.     

Reperfusion pulmonary edema after pulmonary artery thromboendarterectomy

Pulmonary artery thromboendarterectomy (PAT) is a potentially curative procedure in chronic, major vessel thromboembolic pulmonary hypertension. However, postoperative reperfusion pulmonary edema (RPE) has been a serious complication, often requiring prolonged mechanical ventilation. This entity has been described only anecdotally in the past. To characterize it more fully, we retrospectively analyzed the course and potential determinants of RPE after thromboendarterectomy in 22 patients who had PAT at our institution from 1969 through 1984. Particular attention was directed to clinical data, thrombus location, areas operated, postoperative roentgenograms, and preoperative and postoperative hemodynamic data. In all patients but 1, RPE developed within 72 h after surgery, corresponding to anatomic locations distal to vessels subjected to PAT. Regions of lung not reperfused at surgery were uniformly spared. Pulmonary capillary wedge and/or left atrial pressures preoperatively and postoperatively were not elevated. None of the preoperative data predicted which patients would develop more persistent RPE. These observations suggest that the phenomenon of RPE is a peculiar, focal form of pulmonary edema, the basis for which remains to be defined.     

Nitroglycerin-responsive pulmonary hypertension in idiopathic pulmonary hemosiderosis

Idiopathic pulmonary hemosiderosis (IPH) is an uncommon disease found predominantly in pediatric patients. It can produce severe chronic pulmonary injury that results in chronic hypoxemia, pulmonary insufficiency, and progressive pulmonary fibrosis, leading to irreversible pulmonary hypertension and death. We studied the pulmonary hemodynamics in an 9-yr-old boy with IPH to determine if pulmonary hypertension contributed to exacerbations of this disease. Our results showed that this patient demonstrated pulmonary hypertension during acute exacerbations. Initially, the elevated pulmonary artery pressure responded both to oxygen and to a pulmonary vasodilator in the form of nitroglycerin. However, this improvement was not sustained. We conclude that pulmonary hypertension is probably a result of chronic hypoxemia experienced by patients with pulmonary hemosiderosis. Further investigation is warranted to assess whether or not intervention aimed at reducing pulmonary artery pressure in IPH improves outcome.     

Primary pulmonary artery sarcoma mimicking pulmonary thromboembolism

A 69-year-old woman presenting with dyspnea had a pericardial window created for fibrinous pericarditis. The patient subsequently developed pulmonary hypertension and a ventilation perfusion scan was compatible with pulmonary thromboembolism. A primary tumour of the pulmonary artery was suggested by angiography, computerized axial tomography and magnetic resonance imaging. Pathology confirmed a spindle cell pulmonary artery sarcoma.     

Residual pulmonary thromboemboli after acute pulmonary embolism

BackgroundAfter an acute pulmonary embolism (PE), the complete resolution of thromboemboli may not be routinely achieved. The rate of persistence may depend on the time and the diagnostic technique used for evaluation.Patients and methodsPatients were diagnosed with acute PE by means of computed tomography angiography (CTA). While they were receiving anticoagulant therapy, a second CTA was used to explore the rate of persistence of residual thromboemboli. During the initial episode, the plasma levels of Troponin I and natriuretic peptide, patient demographics, and hemodynamic and gas exchange data were evaluated as risk factors for persistence of pulmonary thromboemboli.ResultsIn this study 166 patients were diagnosed. A second CTA was not made in 46 (28%) patients for different reasons. In 120 (72%) patients a second CTA was made 4.5 [SD2.34] months after the initial episode (range 2–12 months). Complete clearance of thrombi occurred in 89 (74%, 95% CI 65–81) patients. Residual thrombi remained in 31 (26%, 95% CI 18–34) patients. In 6%, 13% and 81% of the patients the size of the residual thrombi was greater, similar to and smaller than initially diagnosed, respectively.The risk factors for residual thrombi included the thrombotic burden (OR 1.95), the alveolar to arterial difference of oxygen (OR 1.64), and the clinical antecedents of venous thromboembolic disease (OR 0.65).ConclusionsAfter 4.5 months of anticoagulant therapy, residual pulmonary thromboemboli persisted in 26% of the patients. The risk factors for residual thromboemboli include a greater initial thrombotic burden, a deeper gas exchange disturbation and a history of previous venous thromboembolism.     

Balloon-occlusion pulmonary cineangiography for diagnosing pulmonary embolism

For the angiographic diagnosis of pulmonary embolism (PE) we performed balloon-occlusion pulmonary cineangiography in ten consecutive patients. The technical aspects of the balloon-occlusion cineangiographic technique are reviewed, and its complementary role in the diagnosis of PE are outlined and illustrated with several examples.     

Ruptured pulmonary artery aneurysm mimicking pulmonary embolism

Aneurysms of the pulmonary artery are very rare pathological vascular conditions. Peripheral pulmonary aneurysms have been reported only in a few cases. The causes of these aneurysms include extensive degenerative changes, traumas, infection and congenital malformations. Because of the imminent danger of rupture, surgical treatment should always be preferred. The following case report demonstrates one of a multitude of possible misdiagnoses for rupture of a pulmonary aneurysm.     

Acute pulmonary embolism and pulmonary infarction]

32 cases of pulmonary embolism were reported, 18 cases had been autopsied (massive pulmonary embolism 9 cases. moderate pulmonary embolism 23 cases). The incidence risk factors pathogenesis, clinical manifestations of pulmonary embolism were presented. The relation between pulmonary embolism and pulmonary infarction and treatment of massive pulmonary infarction were discussed.     

特发性肺纤维化与肺动脉高压

特发性肺纤维化（idiopathic pulmonary fibrosis,IPF）是指原因不明并以普通型间质性肺炎（usual interstitial pneumonia,UIP）为特征性病理改变的一种慢性炎症性间质性疾病，主要表现为弥漫性肺泡炎、肺泡单位结构紊乱和肺纤维化。病情多呈进行性发展，晚期可出现发绀、肺动脉高压（pulmonary arterial hypertension, PAH）、肺源性心脏病、右心功能不全等。     

慢性阻塞性肺疾病与肺构形重建

目的　观察慢性阻塞性肺疾病（ Ｃ Ｏ Ｐ Ｄ） 合并肺心病尸检２０ 例的肺部病变特征及其与肺构形重建的关系。方法　常规或低压（１８４ ～３３４ ｍ ｍ Ｈｇ） 福尔马林灌注固定肺组织。用点计数法检测大肺片的肺气肿百分值。常规切片、 Ｚｅｉｓｓ 显微测微器定量测量细支气管的病变特征和肺间质纤维化所占百分值。天狼猩红苦味酸染色,偏振光镜观察,真彩色图像分析Ⅰ、Ⅲ两型胶原分布比值。结果　 Ｃ Ｏ Ｐ Ｄ 病例中以不规则型和囊泡型肺气肿最多见（１７／２０） ,１３ 例有中度和重度肺气肿,心重＞ ４００ｇ 者６ 例。肺纤维化组织占肺总切面积平均为（２７１ ±２９） ％ ,对照组为（１２０ ±１８） ％ ;Ⅰ型与Ⅲ型胶原面积比为５６∶１ ,对照组为１３∶１ ; Ｃ Ｏ Ｐ Ｄ 组１ ５０４ 支细支气管均有慢性细支气管炎,其中合并急性炎症者占３８ ％ ;管腔狭窄和纤维性闭锁者占５３ ％ 。结论　急、慢性细支气管炎和细支气管周围炎是 Ｃ Ｏ Ｐ Ｄ 的重要肺部病变,也是导致肺组织和血管构形重建的重要环节。