Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension: realising the potential of multimodal management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. Important advances have enabled better understanding, characterisation, and treatment of this condition. Guidelines recommending systematic follow-up after acute pulmonary embolism, and the insight that CTEPH can mimic acute pulmonary embolism on initial presentation, have led to the definition of CTEPH imaging characteristics, the introduction of artificial intelligence diagnosis pathways, and thus the prospect of easier and earlier CTEPH diagnosis. In this Series paper, we show how the understanding of CTEPH as a sequela of inflammatory thrombosis has driven successful multidisciplinary management that integrates surgical, interventional, and medical treatments. We provide imaging examples of classical major vessel targets, describe microvascular targets, define available tools, and depict an algorithm facilitating the initial treatment strategy in people with newly diagnosed CTEPH based on a multidisciplinary team discussion at a CTEPH centre. Further work is needed to optimise the use and combination of multimodal therapeutic options in CTEPH to improve long-term outcomes for patients.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Incidence of chronic thromboembolic pulmonary hypertension in Taiwan

BACKGROUND

The diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) is complex, and the modality of treatment is surgery and targeted medication. Patients with CTEPH could have a poor prognosis if their diagnosis or treatment is delayed. The incidence of CTEPH and its clinical features are largely unknown in Taiwan, even among other Asian populations. In this study, we aimed to investigate the geodemographics of CTEPH in Taiwan and describe the practical management and treatment outcomes in patients with CTEPH.

METHODS

This study retrospectively enrolled patients in the Taiwan cohort - Registry of CTEPH. The study was conducted over 2 years inclusive of follow-up. The enrolment criteria depended on the current global guideline.

RESULTS

From January 2018 to March 2020, 107 CTEPH patients enrolled in the Taiwan registry. All patients received right heart catheterisation examinations. The overall median age was 61.4 ± 16.5 years, and the cohort was dominated by female patients (75/107). Risk factors included pulmonary embolism (81.3%), deep vein thrombosis (22.4%), and previous major surgery (20.6%). Twenty-one (19.6%) patients underwent pulmonary endarterectomy operation alone, and 38 (35.5%) patients underwent balloon pulmonary angioplasty alone.

CONCLUSION

To our knowledge, this is the first national cohort study that demonstrated the raw CTEPH incidence in Taiwan. It also showed the CTEPH incidence between male and female patients in the Asian population was different from the Caucasian population.

Chronic Thromboembolic Pulmonary Hypertension: Endovascular Treatment

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare cause of pulmonary hypertension; less than 5% of pulmonary hypertension is caused by recurrent pulmonary thromboembolism (PTE). By definition, CTEPH happens within the first two years after symptomatic PTE; however, cases are often diagnosed without a history of acute PTE. Because of the poor functional status and chronicity of this disease, the classic and curative strategy of open pulmonary endarterectomy cannot be applied in some patients with lesions that involve the distal subsegmental pulmonary artery. Bridging therapy is needed for cases that are technically operable but have an unacceptable risk-benefit assessment or residual symptomatic pulmonary hypertension following surgical removal. Groups in Europe and Japan recently introduced balloon pulmonary angioplasty or percutaneous transluminal pulmonary angioplasty, which has led to significant improvement in functional and hemodynamic parameters in patients with CTEPH. This article introduces recent updates in patient selection and interventional procedures for this chronic and devastating disease.

Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

PURPOSE

To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE).

MATERIALS AND METHODS

62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs).

RESULTS

The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population).

CONCLUSION

Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging.

KEY POINTS

• Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

Successful balloon pulmonary angioplasty with gadolinium contrast media for a patient with chronic thromboembolic pulmonary hypertension and iodine allergy

A 28-year-old male was referred to our hospital with dyspnea. He was diagnosed as having chronic thromboembolic pulmonary hypertension, and a pulmonary endarterectomy (PEA) was performed. However, exertional dyspnea remained because of residual pulmonary hypertension; therefore, the patient was re-admitted to our hospital 1 year after PEA. We performed computed tomography and pulmonary angiography and found web and band lesions in the distal pulmonary artery with a high pulmonary artery pressure. Although further management was complicated because the patient had an anaphylactic shock to iodine-based contrast media, we eventually completed five sessions of balloon pulmonary angioplasty (BPA) using gadolinium contrast medium. His symptoms and hemodynamics dramatically improved after a series of BPA. After 15 months, mean pulmonary arterial pressure reduced from 67 mmHg to 20 mmHg, and subjective symptoms improved from stage Ⅳ to I as per the WHO classification system. BPA is a potential procedure for residual pulmonary hypertension after PEA and could be safely performed using gadolinium contrast medium for patients with iodine allergy.

Diagnostic accuracy of computed tomography for chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

This study aimed to determine the diagnostic accuracy of computed tomography imaging for the diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH). Additionally, the effect of test and study characteristics was explored. Studies published between 1990 and 2015 identified by PubMed, OVID search and citation tracking were examined. Of the 613 citations, 11 articles (n=712) met the inclusion criteria. The patient-based analysis demonstrated a pooled sensitivity of 76% (95% confidence interval [CI]: 69% to 82%), and a pooled specificity of 96% (95%CI: 93% to 98%). This resulted in a pooled diagnostic odds ratio (DOR) of 191 (95%CI: 75 to 486). The vessel-based analyses were divided into 3 levels: total arteries、main+ lobar arteries and segmental arteries. The pooled sensitivity were 88% (95%CI: 87% to 90%)、95% (95%CI: 92% to 97%) and 88% (95%CI: 87% to 90%), respectively, with a pooled specificity of 90% (95%CI: 88% to 91%)、96% (95%CI: 94% to 97%) and 89% (95% CI: 87% to 91%). This resulted in a pooled diagnostic odds ratio of 76 (95%CI: 23 to 254),751 (95%CI: 57 to 9905) and 189 (95%CI: 21 to 1072), respectively. In conclusion, CT is a favorable method to rule in CTEPH and to rule out pulmonary endarterectomy (PEA) patients for proximal branches. Furthermore, dual-energy and 320-slices CT can increase the sensitivity for subsegmental arterials, which are promising imaging techniques for balloon pulmonary angioplasty (BPA) approach. In the near future, CT could position itself as the key for screening consideration and for surgical and interventional operability.

Chronic thromboembolic pulmonary hypertension: an underdiagnosed entity?

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only cause of pulmonary hypertension for which there is a potential cure, which is in the form of pulmonary endarterectomy. There is a strong link between pulmonary embolism (PE) and the development of CTEPH. Although CTEPH was initially believed to be a rare complication, this belief has been reconsidered following several studies suggesting that up to 8.8% of patients develop CTEPH within the 2 years after PE. However, considering the incidence of PE, there is a significant discrepancy in the number of patients who are diagnosed, referred, and treated for CTEPH. Potential reasons for this include its often vague clinical presentation, the variable association of CTEPH with PE, and discrepancies when interpreting imaging studies. Underdiagnosis of CTEPH is preventing patients from accessing potentially curative therapy. Increased awareness about this condition is an important initial step to improving diagnostic rates and treatment.

Natural history of venous thromboembolism

Venous thromboembolism (VTE) originates in systemic venous thrombosis and has different etiological mechanisms and natural history from arterial thrombosis. VTE typically originates as deep venous thrombosis in a lower extremity, where it may give rise to acute symptoms “upstream” from the obstructed vein, result in pulmonary embolism, and/or cause chronic venous obstruction. Pulmonary embolism may result in acute respiratory symptoms, cardiovascular collapse and, uncommonly, may also cause chronic disease.

Rapid clearance of circulating haptoglobin from plasma during acute pulmonary embolism in rats results in HMOX1 up-regulation in peripheral blood leukocytes

BACKGROUND

Acute pulmonary embolism (PE) causes pulmonary hypertension (PH) via several mechanisms including pulmonary vasospasm. We hypothesize that PE with associated PH leads to alterations in plasma protein concentrations indicative of disease severity and prognosis.

OBJECTIVE

To identify plasma proteins altered in abundance by PE in rats.

METHODS

Plasma samples were obtained from rats at 2, 6 and 18 h after experimental PE produced with intrajugular injection of polystyrene beads at three different levels of severity (mild, moderate and severe). Total plasma protein was separated using two-dimensional sodium dodecylsulfate-polyacrylamide gel electrophoresis (2D SDS-PAGE) and candidate protein spots altered in expression by PE were identified by mass spectroscopy. Haptoglobin identity and amount was verified by western blot analysis.

RESULTS

The PE model produced a dose-dependent increase in right ventricular systolic pressure (RVSP) (mmHg) at 2 h: mild 39+/-1.7, moderate 40+/-1.8 and severe 51+/-1.3 mmHg, coincident with significant increases in free plasma (hemoglobin). Combined 2D SDS-PAGE and Western blot analysis indicated time- and dose-dependant loss of plasma haptoglobin levels in response to acute PE. Haptoglobin (HP) was essentially absent from plasma within 2 h of severe PE. Clearance of HP from plasma was accompanied by increased expression of heme oxygenase-1 (hmox1) in peripheral blood leukocytes and in HMOX1 enzyme activity in the liver.

CONCLUSIONS

PE that causes pulmonary hypertension is associated with haptoglobin depletion and up-regulation of HMOX1 enzyme.

The impact of strict infection control on survival rate of prenatally diagnosed isolated congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Although the prognosis of congenital diaphragmatic hernia (CDH) is determined by the degree of pulmonary hypoplasia, there may be an occult contribution of infection to outcomes. The purpose of this study is to evaluate the effects of our new supportive therapy to prevent infectious complications on mortality and morbidity of CDH.

METHODS

Among 57 cases with CDH treated between 2002 and 2007, 43 prenatally diagnosed isolated cases were enrolled in this study. All patients were managed by a lung-protective strategy and delayed surgery. Since January 2006, we have optimized our perioperative care to reduce infectious complications by using peripherally inserted central catheters and restriction of invasive procedures including extracorporeal membranous oxygenation (ECMO). The survival rate, intubation period, maximum serum C-reactive protein (CRP) level, and complications were compared before and after the introduction of refined supportive therapy.

RESULTS

There were 25 cases (12 liver-up, 13 liver-down) treated before 2006 and 18 cases (8 liver-up, 10 liver-down) after 2006. ECMO was required for stabilization in five cases before 2006. The survival rates of total, liver-up, and liver-down cases improved from 60, 42, 77, to 83, 63, 100% after 2006, respectively. The intubation period was shortened from 37.8 +/- 24.3 to 22.2 +/- 10.8 days, and the maximum serum CRP level declined from 12.8 +/- 11.5 to 2.2 +/- 1.6 mg/dl after 2006. Nine cases developed sepsis before 2006 whereas no patients suffered from sepsis or pneumonia after 2006.

CONCLUSION

The new supportive therapy with strict infection control improved survival rate of prenatally diagnosed CDH without using ECMO.

Pulmonary hypertension: clinical manifestations, classification and diagnosis

Dyspnoea on exertion is the most common presenting symptom of pulmonary hypertension (PH), often a progressive and ultimately fatal condition. However, the presenting manifestations are protean, and more subtle features such hoarseness (caused by compression of the left recurrent laryngeal nerve) challenge master clinicians. Clinician scientists have refined the clinical classification in a manner that aids in accurate diagnosis and facilitates communication among healthcare providers and research investigators. Diagnostic algorithms emphasize confirmation and characterization of PH by catheterisation as well as differentiating between the current classes based upon essential and contingent diagnostic tests.

Reverse right ventricular remodeling after pulmonary endarterectomy in patients with chronic thromboembolic pulmonary hypertension: Utility of magnetic resonance imaging to demonstrate restoration of the right ventricle

OBJECTIVES

Pulmonary arterial hypertension causes right ventricular remodeling; that is, right ventricular dilatation, hypertrophy, and leftward ventricular septal bowing. We studied the effect of pulmonary endarterectomy on the restoration of right ventricular remodeling in patients with chronic thromboembolic pulmonary hypertension by magnetic resonance imaging.

METHODS

In 17 patients with chronic thromboembolic pulmonary hypertension, before and at least 4 months after pulmonary endarterectomy, and in 12 healthy controls, right ventricular and left ventricular end-diastolic and end-systolic volumes (milliliters) and mass (grams per meter squared) and leftward ventricular septal bowing (1 divided by the radius of curvature in centimeters) were determined by magnetic resonance imaging.

RESULTS

Before pulmonary endarterectomy, right ventricular volumes, left ventricular end-diastolic volume, right ventricular mass, and leftward ventricular septal bowing differed significantly between patients with chronic thromboembolic pulmonary hypertension and healthy control subjects. After pulmonary endarterectomy, pulmonary hemodynamics improved, and right and left ventricular volumes and leftward ventricular septal bowing normalized; right ventricular mass decreased significantly (46 +/- 14 to 31 +/- 9 g x m(-2), P< .0005), but did not completely normalize. The change in total pulmonary resistance correlated with the change in right ventricular ejection fraction (r = 0.50, P < .05), right ventricular mass (r = 0.63, P < .01), and leftward ventricular septal bowing (r = 0.50, P < .05).

CONCLUSIONS

Right ventricular remodeling was observed in patients with chronic thromboembolic pulmonary hypertension and restored almost completely after a hemodynamically successful pulmonary endarterectomy. Magnetic resonance imaging is a valuable tool to evaluate cardiac remodeling and function in patients with chronic thromboembolic pulmonary hypertension, both before and after pulmonary endarterectomy.

Diagnosis and treatment of deep-vein thrombosis

Deep-vein thrombosis (DVT) is a common condition that can lead to complications such as postphlebitic syndrome, pulmonary embolism and death. The approach to the diagnosis of DVT has evolved over the years. Currently an algorithm strategy combining pretest probability, D-dimer testing and compression ultrasound imaging allows for safe and convenient investigation of suspected lower-extremity thrombosis. Patients with low pretest probability and a negative D-dimer test result can have proximal DVT excluded without the need for diagnostic imaging. The mainstay of treatment of DVT is anticoagulation therapy, whereas interventions such as thrombolysis and placement of inferior vena cava filters are reserved for special situations. The use of low-molecular-weight heparin allows for outpatient management of most patients with DVT. The duration of anticoagulation therapy depends on whether the primary event was idiopathic or secondary to a transient risk factor. More research is required to optimally define the factors that predict an increased risk of recurrent DVT to determine which patients can benefit from extended anticoagulant therapy.

Pulmonary endarterectomy

Chronic thromboembolic pulmonary hypertension is a condition that is recognised in an increased percentage of patients. Pulmonary endarterectomy is recognised as being the only curative option for a subgroup of those patients, but anaesthesiologists and intensivists face many challenges in how they manage these patients perioperatively. Ultimately, it is the combination of skills in a multidisciplinary team that leads to a successful procedure and dramatically improves patient's quality of life and life expectancy.

Life-threatening acute and chronic thromboembolic pulmonary hypertension and subclavian vein thrombosis

Severe thromboembolic pulmonary hypertension is an infrequent but potentially fatal complication of effort thrombosis (Paget-Schroetter syndrome) of the upper extremity. It has been sporadically reported in the literature, but in most cases has affected young, otherwise healthy athletes. Because this syndrome has been rarely described, it is likely underdiagnosed, and optimal evaluation and treatment has not been established. We describe three young athletic persons who developed thrombosis of the subclavian vein after repetitive motion of the upper extremity, and in whom life-threatening pulmonary hypertension resulted from acute and chronic pulmonary emboli. We then review the mechanism, clinical presentation, diagnosis, and available therapeutic modalities.

Multiple peripheral pulmonary artery stenoses in adults: a rare cause of severe pulmonary hypertension necessitating lung transplantation

Stenoses of multiple peripheral pulmonary artery branches represent a rare cause of pulmonary hypertension in children, but the prognosis is very poor for such patients. Herein we describe 2 patients with multiple peripheral pulmonary artery stenoses (MPPAS) presenting with severe pulmonary arterial hypertension in adulthood, which has only once been described previously. Both patients lived without significant health problems for decades; however, after onset of symptoms, their medical condition declined rapidly, necessitating lung transplantation several months after the diagnosis despite vasodilator therapy. Because MPPAS mimics chronic thromboembolic pulmonary hypertension, this entity may being underdiagnosed, decreasing the possibility of adequate therapy.

Etiology-specific endothelin-1 clearance in human precapillary pulmonary hypertension

STUDY OBJECTIVES

Endothelin (ET)-1 is a mediator of vascular remodeling seen in human pulmonary hypertension (PH), and it is normally cleared via endothelial ET-B receptors. Increased levels of ET-1 are found in precapillary PH, partly from increased synthesis. We hypothesized that the endothelial dysfunction and vascular remodeling seen in human precapillary PH would also reduce ET-1 clearance.

DESIGN AND SETTING

Case series from a single institutional PH center.

PATIENTS

Thirty-four patients with pulmonary arterial hypertension (PAH; idiopathic [IPAH], n = 19; connective tissue disease [CTD], n = 15) and 11 patients with chronic thromboembolic PH were studied.

MEASUREMENTS AND RESULTS

Using indicator dilution methods, the first-pass extraction of radiolabeled ET-1 through the pulmonary circulation, and permeability surface (PS) area, an index of functional microvascular surface available for ET-1 clearance, were determined. Mean extraction for IPAH and thromboembolic PH groups was normal, but it was reduced in PAH from CTD; 69% of all patients studied had normal extraction. The mean PS product was reduced significantly for all three etiologies as compared to normal, but 58% of IPAH patients and 40% of CTD-related PAH patients had normal PS products.

CONCLUSIONS

Receptor-mediated ET-1 extraction and functional vascular surface area for clearance vary between etiologies of PAH. However, contrary to our hypothesis, endothelial ET-B receptor-mediated extraction is preserved in many patients. The scientifically significant finding of our study is that high ET-1 levels seen in patients with PAH must be predominantly due to excess synthesis rather than reduced clearance. The finding that endothelial ET-B receptors are still present and functional in PAH may also be of relevance to the choice of selective vs nonselective ET receptor antagonists.

Diagnosis and evaluation of the patient with pulmonary hypertension

The term pulmonary hypertension is as imprecise as the term heart failure. Elevation in pulmonary arterial pressure can be caused by heterogeneous processes with profoundly different treatment implications. Pulmonary hypertension can present at any age and across all demographic ranges. Despite major advances in pathogenesis and treatment for pulmonary arterial hypertension, the diagnosis of this life-threatening but treatable condition often remains delayed and incomplete. Because the presenting symptoms of pulmonary hypertension are nonspecific, a high index of suspicion is required for timely recognition. Accordingly, suspecting or recognizing pulmonary hypertension remains the first and critical hurdle in the diagnosis of pulmonary hypertension. This article reviews the stepwise approach necessary for an efficient and accurate diagnosis of pulmonary hypertension.

Chronic thromboembolic pulmonary arterial hypertension: correlation of postoperative results of thromboendarterectomy with preoperative helical contrast-enhanced computed tomography

INTRODUCTION

Pulmonary thromboendarterectomy is the treatment of choice for patients with chronic thromboembolic pulmonary arterial hypertension (CTEPH). Some patients do poorly after this procedure and may be better candidates for heart-lung transplant. The purpose of this study was to correlate preoperative findings on helical contrast-enhanced computed tomography (CT) with surgical outcome.

METHODS

Thirty-seven patients (mean age 52.9, range 22-71) who underwent pulmonary thromboendarterectomy and had preoperative helical contrast-enhanced CT followed by High Resolution CT (HRCT) scans were included in the study. The CTs were evaluated for the presence of central and segmental disease and for the presence of mosaic perfusion pattern.

RESULTS

The presence of central disease, as well as the presence of segmental disease, correlated negatively with the postoperative mean pulmonary arterial pressure [r(c) = -0.401, P = 0.015, r(s) = -0.38, P = 0.024)] and the pulmonary vascular resistance [(r(c) = -0.37, P = 0.027, r(s) = -0.39, P = 0.019]. No correlation was found between the clinical variables and the presence of mosaic perfusion pattern.

CONCLUSION

Patients with CTEPH and evidence of chronic PE in the central or segmental pulmonary arteries have a better clinical outcome after pulmonary thromboendarterectomy than patients without these findings. The presence of mosaic perfusion pattern is not helpful in predicting postoperative outcome.

Surgical pathology of pulmonary thromboendarterectomy: a study of 54 cases from 1990 to 2001

Thromboendarterectomy is performed to treat chronic thromboembolic pulmonary hypertension with obstruction of main, lobar, or segmental pulmonary arteries. The present study evaluated surgical specimens removed between 1990 and 2001. Medical histories and microscopic slides were reviewed in each case. Study slides were stained with hematoxylin and eosin and Verhoeff-van Gieson and evaluated for thrombus, collagen, elastin, atherosclerosis, hemosiderin, calcification, and inflammation. The study group comprised 54 patients (30 women and 24 men), ranging in age from 33 to 77 years (mean, 58 years). Clinically, 28 (52%) had a history of deep leg vein thrombosis and 42 (78%) had a history of pulmonary embolism; 24 (44%) had both events. Coagulation abnormalities were documented in 15 (28%); autoimmune or hematologic disorders, in 8 (15%). Pulmonary thromboendarterectomy was bilateral in 52 patients (96%) and right-sided in 2. Six patients also had obstructions resected from the main pulmonary arteries. Obstruction limited to segmental arteries occurred only in women. Grossly, right-sided specimens were larger than left-sided ones (P = 0.003). Microscopically, ages of thrombi were uniform in 72% and variable in 28%. Intima was thickened in all patients and consisted of collagen (100%), elastin (67%), hemosiderin (56%), inflammation (53%), atherosclerosis (32%), and calcification (15%). We determined that pulmonary thromboendarterectomy was performed most often in middle-aged and elderly patients with a history of deep venous thrombosis or pulmonary embolism. Less than 50% of the patients had an identifiable coagulation, autoimmune, or hematologic abnormality. Most patients had bilateral disease and resections. Right-sided specimens were significantly larger than left-sided specimens, and lower lobe involvement was more common than involvement elsewhere. Resected tissues most commonly exhibited old organized thrombus.

Pulmonary thromboendarterectomy in the UK

This paper describes the disease of chronic thromboembolic pulmonary hypertension. This is a disease with an extremely poor prognosis, and the surgical procedure of pulmonary thromboendarterectomy represents the only possibility of a cure for patients with this condition. Further the paper describes the role and responsibilities of critical care nurses, specialist nurses in palliative care and pulmonary hypertension when caring for these patients before and after surgery.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) should be differentiated from other etiologies of pulmonary hypertension since surgical intervention may be potentially curative. The presentation of this illness is nonspecific and may mimic other cardiopulmonary disease states. Without treatment, progressive pulmonary hypertension, right heart failure, and death will ensue. Echocardiography, lung ventilation-perfusion scan, right heart catheterization, and angiography are required for proper diagnosis and preoperative assessment. Definitive treatment requires surgical resection of thromboembolic material. The role of medical therapy remains to be defined.