急性肺动脉血栓栓塞症的诊断及外科治疗

目的探讨急性肺动脉血栓栓塞症的快速诊断、手术治疗和围手术期处理方法。方法 15例急性肺动脉栓塞症患者均在全麻体外循环下行肺动脉血栓切除术。结果术后10 d动脉血氧分压、动脉血氧饱和度均显著高于术前（P〈0.05）;术后10 d心脏超声右室横径、主肺动脉宽度、三尖瓣反流压差和反流面积均明显缩小（P〈0.05）。全组无手术死亡、并发症,术后全部病例心功能完全恢复正常。结论术前及时明确诊断、严格掌握手术适应证和手术时机、手术彻底清除血栓是治疗急性肺动脉血栓栓塞症成功的关键。     

Unusual cause of acute right ventricular dysfunction: rapid progression of superior vena cava aneurysm complicated by thrombosis and pulmonary thromboembolism

Aneurysms of the major thoracic veins are rare. They are usually asymptomatic and thus treated conservatively. We report an extremely rare case of rapidly progressing superior vena cava (SVC) aneurysm complicated by thrombosis and acute pulmonary thromboembolism (PTE) with right ventricular dysfunction. Thrombolytic therapy for hemodynamically significant acute PTE was harmful to the patient in the present case, because it induced further thrombosis and mobilization of the thrombi within the aneurysm, subsequently causing de novo PTE. Surgical aneurysmectomy combined with pulmonary artery embolectomy would be a treatment of choice in patients with SVC aneurysm complicated by acute PTE.     

慢性肺动脉血栓栓塞动物模型的建立

背景：目前国内外接近人体生理学的慢性肺动脉血栓栓塞的动物模型较少见。 目的：采用自体血栓反复注射法建立慢性肺动脉血栓栓塞的动物模型。 方法：将家兔随机分为栓塞组和假栓塞组,栓塞组家兔肺动脉多次注入自体血栓,假栓塞组用生理盐水替代血栓。 结果与结论：栓塞组干预4周后解剖肺动脉并经病理检测可发现有血栓机化,肺动脉CT造影均可见局部肺动脉截断征,以及炎症、梗死、胸膜增厚等间接征象,肺动脉解剖及病理均可发现实验兔肺动脉血栓形成机化及慢性炎症改变。结果证实,采用兔自体血栓反复注射法可成功建立慢性肺血栓栓塞动物模型。     

A case of deep vein thrombosis and pulmonary thromboembolism after intravenous immunoglobulin therapy

Although high-dose intravenous immunoglobulin (IVIG) is generally considered a safe medication for various immune-mediated diseases, thrombotic events have been reported as a complication of the therapy. We report a case who developed thrombotic complications after receiving IVIG. A 56-yr-old woman with idiopathic thrombocytopenic purpura received IVIG at a dose of 400 mg/kg/day for five days. Three days after the administration of IVIG, the patient developed painful edema in the left leg. Lower extremity doppler ultrasound revealed deep vein thrombosis in the left leg. Chest computed tomography (CT) scan demonstrated a filling defect indicating thromboembolism of the right pulmonary artery. After three weeks of enoxaparin therapy, her symptoms and pulmonary embolism on CT improved. This case suggests clinicians should be cautious in the development of thromboembolism by administration of IVIG, especially in patients with thrombophilia.     

Evaluation of autologous blood clot subsegmental pulmonary thromboembolism in minimally invasive experimental canine model

The incidence and significance of subsegmental pulmonary (SSP) thromboembolism is currently under investigation. We aimed to evaluate the clinical and diagnostic features of SSP thromboembolism in an experimental canine model. Obstruction of pulmonary arterial branches was induced in three beagle dogs by intravenous injection of a barium‐coated autologous blood clot (size, approximately 1.7 × 5 mm). The clinical signs, haemodynamic changes (blood pressure, electrocardiogram, echocardiography), coagulation (aPTT, PT, FDPs and D‐dimer test) and cytokine variations (TNF‐a, IL‐4, IL‐6, and IL‐10) were evaluated over a 24‐hour period. Multidetector computed tomography (MDCT) with contrast was conducted to evaluate the pulmonary obstruction, and histopathological confirmation was performed. Pulmonary artery pressure gradient (PAPG) was increased 12 h after the autologous blood clot injection (14.2 ± 2.8 mmHg to 23.6 ± 1.7 mmHg, P = 0.003) and normalized 24 h later (P < 0.01). Infused radiopaque clots were confirmed with MDCT and histopathological examination. Pulmonary parenchymal changes such as arterial dilation and inflammatory reactions were also confirmed in histopathological examinations and were barely observable in MDCT. Usually small emboli are not easily detected through CT imaging, and the clinical relevance of these emboli is controversial. In this experimental study, we made radiopaque small emboli and induced SSP thromboembolism. Thus, we infer that obstruction of the small segmental and subsegmental pulmonary arteries does result in a pulmonary thromboembolism (PTE) and PTE‐related pulmonary parenchymal changes which could be clinically significant.     

Multifocal distribution of pulmonary capillary haemangiomatosis

AIMS: We investigated a case of pulmonary capillary haemangiomatosis, a rare condition, to determine the extent of the pathological changes within the lungs. Systematic histological sampling has not previously been performed in this condition. METHODS AND RESULTS: A 52-year-old woman with a history of ischaemic cardiomyopathy suffered from repeated respiratory infections, which were attributed to chronic pulmonary congestion. She died suddenly of fulminant pulmonary thromboembolism. An autopsy was performed and lung tissue was sampled at multiple sites. Beside passive congestion, the lungs showed well-circumscribed areas containing proliferations of small capillaries infiltrating the pulmonary septa and the walls of otherwise normal blood vessels and bronchi. The most severely affected areas were found to be in the periphery of both lower lobes. A diagnosis of pulmonary capillary haemangiomatosis was made. CONCLUSIONS: This is the first case of pulmonary capillary haemangiomatosis in which systematic histological sampling has been performed. Mapping of lesions disclosed the multifocal distribution of pulmonary capillary haemangiomatosis in this patient.     

Aminoguanidine produces beneficial haemodynamic effects in a canine model of acute pulmonary thromboembolism

AIM: Activating the nitric oxide (NO)-cyclic guanosine 3',5'-monophosphate (cGMP) pathway improves haemodynamics following acute pulmonary thromboembolism (APT). However, the role of NO synthase (NOS) isoforms in the responses to APT has not been determined. We examined the effects of selective and non-selective inducible NOS (iNOS) inhibition. METHODS: Haemodynamic evaluations were performed in non-embolized dogs treated with saline (control group; n = 4), L-NAME (NAME group; n = 3), or aminoguanidine (AG group; n = 3), and in dogs that received the same drugs and were embolized with 5 mL kg(-1) of clots made with autologous blood (Emb group, n = 9; NAME + Emb group, n = 4 and AG + Emb group, n = 7). The lung concentrations of nitrite/nitrate (NOx) and cGMP were determined by chemiluminescence and ELISA respectively. RESULTS: Acute pulmonary thromboembolism increased mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) by 21.4 +/- 1.7 mmHg and by 843 +/- 34 dyn s cm(-5) m(-2), respectively, in Emb group. MPAP and PVRI increased to higher levels in the NAME + Emb group 15 min after APT and all dogs in this group died 15-30 min after APT. Conversely, lower MPAP and PVRI levels were found in the AG + Emb group 2 h after APT compared with the Emb group (both P < 0.05). Higher NOx concentrations were found in the Emb group compared with the other groups (all P < 0.05). Higher cGMP concentrations were found in the Emb and AG + Emb groups compared with the other groups (all P < 0.05). CONCLUSIONS: These results indicate that endogenous NO protects against APT-induced cardiovascular responses. Moreover, iNOS-derived NO possibly produces unfavourable effects, which are counteracted by aminoguanidine. However, non-NO-related mechanisms may also be involved.     

Malignant fibrous histiocytoma of the heart presenting as unilateral pulmonary thromboembolism and infarct

A malignant fibrous histiocytoma of the heart located at the pulmonic valve and thrombotic occlusion of branches of the left pulmonary artery with pulmonary infarct were found at autopsy in a 77-year-old man. The thrombi contained malignant cells. The patient had undergone left upper lobectomy four years earlier for thromboembolism with infarct, and review of the slides from that procedure revealed similar malignant cells within thrombi. This case is remarkable for the slow growth of the neoplasm and the prolonged survival of the patient, without specific therapy.     

Seasonal variation in the necropsy incidence of pulmonary thromboembolism in Hong Kong.

The seasonal variation in the necropsy incidence of significant pulmonary thromboembolism in Hong Kong was investigated. A total of 3446 adult Chinese necropsies carried out in Queen Mary Hospital, Hong Kong, from 1987 to 1992 showed an overall rate of 3.77% for significant pulmonary thromboembolism. The rates for individual months were calculated and compared. The pattern of seasonal variation showed that there are two troughs in early summer (June, July) and early winter (November, December), with rates between 1.6% and 2.4%. The rates in the months for the rest of the year were between 4.0% and 5.5%. The overall pattern was similar to that of the temperate zone although the climate was quite different.     

Intraparenchymal pulmonary lipoma: pathologic-radiologic correlation of a rare presentation of a common neoplasm

We report a rare case of pulmonary intraparenchymal lipoma. Lipomas are benign adipocytic tumors, which are ubiquitous in distribution, particularly in the subcutis and soft tissue. Visceral lipomas, in particular, pulmonary lipomas, are rarely reported. Even rarer are intraparenchymal lipomas, such as this case, of which less than 10 have been reported in the medical literature. The radiologic (computed tomographic scan) findings of pulmonary lipoma may be somewhat difficult to evaluate. In this case, on initial review, the computed tomographic findings were not diagnostic, but retrospective analysis revealed attenuation values suggestive of an adipocytic lesion. A high index of suspicion and careful attention to attenuation values are therefore required for radiologic diagnosis. Excision is necessary for histologic confirmation, which is generally relatively straight forward, although admixture with fibrous tissue and some cytologic atypia may pose diagnostic challenges.     

Choriocarcinoma-associated pulmonary thromboembolism and pulmonary hypertension: a case report

Cases of pulmonary embolism and pulmonary artery hypertension caused by choriocarcinoma represent a rare clinical emergency. We report a case of a 25-year-old woman who presented with pulmonary embolism and hypertension and died soon after complete pulmonary embolectomy. A related literature review revealed that almost all of these patients had previously experienced a spontaneous abortion (average, 6 months) and were not pregnant.     

Pulmonary thromboembolism: frequency, site, and vascular change in 103 autopsy cases

For investigation of the incidence of pulmonary thromboembolism, the sites of thromboemboli, pulmonary vascular changes, detailed clinical and autopsy records, and histological sections of a series of 103 autopsied adults were reviewed. Pulmonary thromboembolism was observed in 38.8% of these cases. Pulmonary thromboembolism tended to be more frequent in older, younger, female, and cancer patients. Thromboembolism was found most frequently in arterioles, followed by muscular arteries. A significant correlation (P less than 0.02) was found between the incidence of pulmonary thromboembolism and the histological changes of endothelial protrusion and vacuolization of the intima in these small pulmonary arteries, but no correlation was found between that of pulmonary thromboembolism and constriction figures. These endothelial changes probably represent previous vasoconstriction. The present observations suggest a significant relationship between pulmonary thromboembolism and vasoconstriction of small pulmonary arteries and suggest that widespread vasoconstriction of pulmonary arteries is important in the pathogenesis and pathophysiology of this condition.     

Sudden and unexpected death in infancy and childhood due to pulmonary thromboembolism. An autopsy study

Because massive pulmonary thromboembolism is a rarely described cause of sudden and unexpected death in the pediatric age group, a 50-year retrospective review of autopsy cases at the Hospital for Sick Children, Toronto, Canada, was conducted to determine the local incidence and clinicopathologic features of such patients. Only 8 cases (0.05%) from a total of approximately 17,500 autopsies were found. The ages ranged from 1 month to 13 years and predisposing factors included recent surgery, congenital heart disease, in-dwelling venous catheters, sepsis, an arteriovenous malformation, occult malignancy, and prolonged immobility. This study confirms that pulmonary thromboembolism is a diagnosis that must be considered in cases of sudden and unexpected death in the pediatric age group. Its incidence, however, appears to be extremely low even in a relatively high-risk population.     

Colonic lipoma with florid vascular proliferation and nodule-aggregating appearance related to repeated intussusception

A unique case of repeatedly intussuscepted colonic lipoma mimicking an epithelial tumor in a 50-year-old man is reported. The tumor was located in the ascending colon and was approximately 5 cm in diameter. Colonoscopic and barium-enema examinations suggested a huge epithelial tumor because of its nodule-aggregating appearance. In contrast, computed tomography examination showed a fatty element in the core of the lesion. The biopsy specimens suggested a primary angiomatous lesion because of its pronounced vascular proliferation. Because the presumed diagnoses based on the examinations were different, the preoperative diagnosis was not confirmed. The tumor was composed of intramural lipoma with a multiple polypoid mucosa overlay. This lesion was unique in that the lipoma appeared to be within the muscularis propria and the multiple polypoid appearance of its covering mucosa. The mucosal changes including florid vascular proliferation, fibromuscular obliteration and epithelial regeneration suggested a reparative process, with ischemic damage due to the effects of intussusception being the most likely event. It should be kept in mind that even a simple lipoma can have a unique appearance reminiscent of epithelial tumor when it repeatedly experiences intussusception.     

Clinical-pathologoanatomic analysis of post-operative thromboembolism of pulmonary artery

Autopsy and clinical data were analysed for 803 surgical patients whose death was due to pulmonary artery thromboembolism (PAT). PAT was diagnosed intravitally in 32% of the deceased. 87% of the patients with PAT symptoms died within 2 hours. 3/4 of PATs developed in uneventful postoperative period, 1/4--in complications. The cause of PAT in 99.3% of cases were thromboses in vena cava inferior. In 88.3% of cases these thromboses ran latently. Frequency of postoperative PAT as a cause of death was 1.4% in 1972-1973, 2.1% in 1990-1991, 1.3% in 1997. The fall of the death rate is explained by introduction of drug prophylaxis of PAT.     

Spontaneous disruption of mycotic aneurysm involving innominate artery

We report a case of ruptured mycotic aneurysm involving innominate artery requiring an urgent surgical treatment. A 62-yr-old woman presented with fever and dyspnea. Previously, she was diagnosed with colon cancer and received right hemicolectomy and one cycle of adjuvant chemotherapy. On echocardiogram, pericardial effusion was noted and emergency pericardiocentesis was performed. CT scan revealed aortic aneurysm involving ascending aorta and innominate artery, and thrombi surrounding those structures. Patch repair of the defect in the ascending aorta and ringed Goretex graft to bypass the innominate and ascending aorta were performed. We believe that this is the first case of ruptured mycotic aneurysm involving innominate artery.     

Risk factors of recurrent venous thromboembolism: the role of residual vein thrombosis

In 313 consecutive symptomatic outpatients with proximal deep vein thrombosis (DVT) who had a conventional anticoagulation, an ultrasound assessment of the common femoral and the popliteal vein was performed three months after the acute episode, and then at 6, 12, 24, and 36 months. Veins were considered as recanalized in case of a vein diameter < 2.0 mm in a single determination, or < 3.0 mm in two consecutive determinations. Of the 58 patients who experienced recurrent episodes, 41 occurred while the patient still had residual thrombosis. The hazard ratio of recurrent thromboembolism was 2.4 (95% CI, 1.3 to 4.4; p =0.004) for persistent residual thrombosis versus early vein recanalization. In conclusion, residual venous thrombosis should be regarded as an important risk factor of recurrent thromboembolism.     

A case of pulmonary artery intimal sarcoma diagnosed with multislice CT scan with 3D reconstruction

Pulmonary artery intimal sarcoma is a rare highly lethal disease, with additional retrograde extension to pulmonic valve and right ventricle being an extremely rare condition. It is frequently mistaken for pulmonary thromboembolism. We report a case of 64-year-old woman with progressive dyspnea initially suspected and treated for pulmonary thromboembolism. Her helical chest CT scan with 3 dimensional (3D) reconstruction combined with echocardiography revealed a compacting main pulmonary artery mass extending to the right ventricular outflow tract and the right pulmonary artery. After excision of the mass, the patient's condition improved dramatically, and the pathologic findings revealed pulmonary intimal sarcoma. This report emphasizes that helical chest CT with 3D reconstruction can be an important tool to differentiate the characteristics of pulmonary artery lesions, such as intimal sarcoma and thromboembolism.     

Sudden death caused by pulmonary thromboembolism in Proteus syndrome

We report 3 patients with Proteus syndrome (PS) who died suddenly from pulmonary embolism (PE). The first patient was a male diagnosed with PS at 12 years who had varicose veins, portal vein thrombosis, right iliac vein occlusion and recurrent PE. At age 25 years, he was admitted to the hospital with a severe headache. Despite therapeutic doses of warfarin, investigations for an acute episode of breathlessness showed PE and he was unable to be resuscitated. The second case was a 9-year-old male with PS who collapsed at home and could not be revived. Autopsy revealed that the cause of death was a PE associated with thrombosis of the deep veins (DVT). The third patient was a 17-year-old female undergoing inpatient treatment for sinusitis when she unexpectedly arrested. She could not be revived and a full autopsy revealed a large PE with no identified DVT. We conclude that PE is a serious complication of PS and recommend vigilance concerning the signs and symptoms of thrombosis and PE in individuals with PS, including children. Aggressive evaluation and treatment should be considered urgently in patients with PS and signs or symptoms of DVT.     

Thrombotic pulmonary arteriopathy in polycythemia vera.

Pulmonary infarction and hemorrhage are important differential diagnoses in pulmonary coin lesions, especially in patients with underlying hematologic malignancies. We report a 58-year-old female patient suffering from polycythemia vera presenting with multiple pulmonary coin lesions. Open lung biopsy and subsequent histologic investigations showed organized pulmonary infarction and primary pulmonary thrombotic arteriopathy. Although histologic features are non-contributory in distinguishing organized thrombosis from organized thromboembolism, the clinical setting and localization of the lesions suggest that in the present case the vascular lesions are due to organized thrombosis.