Assessment of the current and emerging criteria for the histopathological classification of lung neuroendocrine tumours in the lungNENomics project.

BACKGROUND: Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort presents a unique opportunity to assess the strengths and limitations of current World Health Organization (WHO) classification criteria and to evaluate the utility of emerging markers. PATIENTS AND METHODS: Patients were diagnosed based on the 2021 WHO criteria, with atypical carcinoids (ACs) defined by the presence of focal necrosis and/or 2-10 mitoses per 2 mm2. We investigated two markers of tumour proliferation: the Ki-67 index and phospho-histone H3 (PHH3) protein expression, quantified by pathologists and automatically via deep learning. Additionally, an unsupervised deep learning algorithm was trained to uncover previously unnoticed morphological features with diagnostic value. RESULTS: The accuracy in distinguishing typical from ACs is hampered by interobserver variability in mitotic counting and the limitations of morphological criteria in identifying aggressive cases. Our study reveals that different Ki-67 cut-offs can categorise LNETs similarly to current WHO criteria. Counting mitoses in PHH3+ areas does not improve diagnosis, while providing a similar prognostic value to the current criteria. With the advantage of being time efficient, automated assessment of these markers leads to similar conclusions. Lastly, state-of-the-art deep learning modelling does not uncover undisclosed morphological features with diagnostic value. CONCLUSIONS: This study suggests that the mitotic criteria can be complemented by manual or automated assessment of Ki-67 or PHH3 protein expression, but these markers do not significantly improve the prognostic value of the current classification, as the AC group remains highly unspecific for aggressive cases. Therefore, we may have exhausted the potential of morphological features in classifying and prognosticating LNETs. Our study suggests that it might be time to shift the research focus towards investigating molecular markers that could contribute to a more clinically relevant morpho-molecular classification.

Cystic fibrosis-related diabetes screening at a large pediatric center.

OBJECTIVE: Cystic Fibrosis Foundation guidelines recommend annual diabetes screening by oral glucose tolerance test (OGTT) in pediatric patients with cystic fibrosis (CF) starting at the age of 10 years. Adherence to these guidelines proves to be challenging, and the nationwide screening rates are still considered suboptimal. The aim of this study was to assess and improve the screening rates at our large pediatric center. METHODS: A 4-year retrospective audit of OGTT completion among pediatric patients with CF of age ≥10 years who are not yet diagnosed with diabetes was conducted. A collaborative working group was formed to identify the barriers to screening and formulate a quality improvement plan, which was monitored and evaluated for a 9-month period. RESULTS: Diabetes screening rates determined by OGTT completion at our center showed a gradual decline during the COVID-19 pandemic from 2019 to 2022. Following the implementation of the quality improvement plan during the summer of 2023, there was a marked increase in OGTT ordering compliance by providers as well as test completion by patients. Notably, the fractional OGTT completion rate rose from 45% during the preintervention phase (January-April 2023) to 70% during the postintervention phase (May-September 2023). CONCLUSION: Diabetes screening in pediatric patients with CF can be effectively improved by refining practices related to patient experience, care coordination, and laboratory testing strategies.

Controlled donation after circulatory death lung transplantation: Results of the French protocol including in situ abdominal normothermic regional perfusion and ex vivo lung perfusion.

BACKGROUND: The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT). METHODS: We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021. RESULTS: One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%. CONCLUSION: After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.

Cystic fibrosis lung transplant recipients 10 years of age or younger: Predisposing factors for end-stage disease.

BACKGROUND: The largest age group among children and adolescents referred for lung transplantation for cystic fibrosis (CF) have been those in the pubertal or postpubertal age range. However, over 100 younger patients with CF have undergone lung transplantation over the last three decades in the United States. METHODS: We performed a retrospective review of our experience with 18 children with CF who underwent lung transplantation in our center before the age of 11 years and compared them to our older CF lung transplant recipients and our larger CF Center population. RESULTS: The transplant population was demographically distinct from our CF center in terms of ethnicity, country of origin, and insurance status. Other notable findings were a high prevalence of methicillin-resistant Staphylococcus aureus, a high prevalence of CF-related diabetes mellitus, and a high prevalence of consolidated lobar or whole lung disease. Posttransplant outcomes were comparable to those older than 10 years of age in our center until 5 years after transplant after which the younger cohort showed a superior enduring survival. CONCLUSIONS: In an era of increasingly effective medications modifying the natural history of CF, identification of risk factors for early severe lung disease in CF remains relevant to permit interventions to prevent or postpone the time of future lung transplantation.

Radiofrequency ablation versus surgical resection for the treatment of oligometastatic lung disease.

PURPOSE: The purpose of this study was to compare efficacy and tolerance between radiofrequency ablation (RFA) and surgery for the treatment of oligometastatic lung disease. MATERIALS AND METHODS: This retrospective study reviewed patients treated in two institutions for up to 5 pulmonary metastases with a maximal diameter of 4cm and without associated pleural involvement or thoracic lymphadenopathy. Patient demographics, tumor characteristics, treatment outcome, and length of hospital stay were compared between the two groups. Efficacy endpoints were overall survival (OS), progression-free survival (PFS) and pulmonary or local tumor progression rates. RESULTS: Among 204 patients identified, 78 patients (42 men, 36 women; mean age, 53.3±14.9 [SD]; age range: 15-81 years) were treated surgically, while 126 patients (59 men, 67 women; mean age, 62.2±10.8 [SD]; age range: 33-80 years) were treated by RFA. In the RFA cohort, patients were significantly older (P<0.0001), with more extra-thoracic localisation (P=0.015) and bilateral tumour burden (P=0.0014). In comparison between surgery and RFA cohorts, respectively, the 1- and 3-year OS were 94.8 and 67.2% vs. 94 and 72.1% (P=0.46), the 1- and 3-year PFS were 49.4% and 26.1% vs. 38.9% and 14.8% (P=0.12), the pulmonary progression rates were 39.1% and 56% vs. 41.2% and 65.3% (P>0.99), and the local tumour progression rates were 5.4% and 10.6% vs. 4.8% and 18.6% (P=0.07). Tumour size>2cm was associated with a significantly higher local tumor progression in the RFA group (P=0.010). Hospitalisation stay was significantly shorter in the RFA group (median of 3 days; IQR=2 days; range: 2-12 days) than in the surgery group (median of 9 days; IQR=2 days; range: 6-21 days) (P<0.01). CONCLUSION: RFA should be considered a minimally-invasive alternative with similar OS and PFS to surgery in the treatment of solitary or multiple lung metastases measuring less than 4cm in diameter without associated pleural involvement or thoracic lymphadenopathy.

Klippel-Trenaunay syndrome as a rare cause of chronic thromboemboembolic pulmonary hypertension.

Klippel-Trenaunay syndrome (KTS) is a congenital disorder characterized by cutaneous capillary malformations, soft tissue and bone hypertrophy, and multiple capillary, venous or lymphatic malformations. KTS is associated with recurrent thromboembolic events. We reported herein five cases of chronic thromboembolic pulmonary hypertension (CTEPH) associated with KTS (age minimum-maximum 26-50 years old, 3 males/2 females). Hemodynamics showed severe pulmonary hypertension (PH) with pulmonary vascular resistance ranging from 5.6 to 18.3 Wood units (WU), associated with marked clinical impairment (NYHA functional class III or IV in 4 patients). Computed tomography (CT) of the chest and pulmonary angiography confirmed proximal CTEPH accessible to surgical intervention in one patient and distal forms of CTEPH in 4 patients. Evolution after pulmonary endarterectomy showed hemodynamic normalization, while the patients with distal CTEPH had severe outcomes with 2 early deaths after PH diagnosis (44 and 35 months respectively). One patient with distal CTEPH was still alive 16 years after diagnosis on specific PH therapy and one was transplanted after 15 years because of right heart failure (death after 12 months). Histological analysis of the lung explants showed typical chronic thromboembolic material specific for CTEPH. In conclusion, KTS may be complicated by severe CTEPH requiring careful anticoagulation and multidisciplinary follow-up in expert centers to screen for disease potentially accessible to endarterectomy. In the modern management era of CTEPH, balloon pulmonary angioplasty will certainly be an interesting option in patients with inoperable disease.

[Treatment of chronic thromboembolic pulmonary hypertension in elderly patients]. / Traitement du cœur pulmonaire post-embolique chez le sujet âgé.

AIM OF THE STUDY: To establish efficacy and security of invasive treatments for chronic thromboembolic pulmonary hypertension (CTEPH) in elderly patients (≥80 years old): pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA). PATIENTS AND METHODS: Between 2014 and 2017, 549 CTEPH patients were addressed to our hospital for PEA (364 patients) or BPA (225). From this total, patients 80 years old and over were: 17 treated by PEA and 21 by BPA. Demographic characteristics as well as hemodynamic parameters, results and complications were compared for both groups (Young - Y - versus Old - O). RESULTS: Elderly BPA patients presented a higher functional class (mean O: 3,16 versus Y: 2,73; P=0,001), with similar hemodynamics parameters compared with the younger patients. Indication for BPA in the elderly was the presence of comorbidities contraindicating surgery in 33% of cases vs. 9,3% in the younger group (P=0,005). Response to treatment was comparable in both groups with significant reductions of mPAP, PVR and improvement of functional class. Complications rate was alike between groups for hemoptysis, reperfusion lesions or mortality, with the exception of a higher incidence of contrast-induced nephropathy, without need for dialysis, in the elderly group (O: 8,4% versus 2,6%; P=0,010). Elderly PEA patients were more often male (O: 76,5% versus Y: 50,1%; P=0,034) and with a lower creatinine clearance (O: 57,6±13,4 versus Y: 72,2±21,2mL/min/m2; P=0,004). Functional class, hemodynamics, surgical times and in-hospital stay was similar between groups. There is a non-significant trend towards higher in-hospital mortality in the elderly group, CONCLUSIONS: In our experience, treatment of CPC PE in elderly patients, either by PEA or BPA is effective with acceptable complication rates.

Radiotherapy for Tracheal-Bronchial Cystic Adenoid Carcinomas.

AIMS: Primary tracheal-bronchial adenoid cystic carcinoma (thoracic adenoid cystic carcinoma; TACC) is a rare and aggressive malignant tumour. Radiotherapy results have not been previously individualised in this setting. PATIENTS AND METHODS: Records of 31 patients with TACC (74% tracheal and 26% bronchial) who received radiotherapy between February 1984 and September 2014 were retrospectively analysed. RESULTS: Surgical removal of the primary tumour was carried out for most (71%) patients, and 13/22 (59%) had R1 or R2 (1/22) margins. The mean tumour size was 4.1 cm, 10 (32%) had associated lymph node involvement and 13 (41%) had perineural invasion (PNI). Adjuvant and definitive radiotherapy were delivered for 22 (71%) and nine patients, respectively. The mean delivered dose was 62 Gy (40-70 Gy) and eight patients had a radiotherapy boost (mean 19 Gy, range 9-30 Gy, two with endobronchial brachytherapy). At a median follow-up of 5.7 years, the 5 year overall survival and progression-free survival (PFS) rates were 88% and 61%, respectively. There were three local relapses and 10 metastatic relapses (mean delay 3.2 years), resulting in 5 year local and metastatic relapse rates of 10% and 26%, respectively. The prognostic factors in the univariate analysis for both decreased overall survival and PFS were: age ≥50 years (hazard ratio 6.2 and 3.8) and the presence of PNI (hazard ratio 10.3 and 4.1); and for PFS only: a radiotherapy dose ≤ 60 Gy (hazard ratio 3.1). Late toxicities were: tracheotomy due to symptomatic tracheal stenosis (n = 5), G3 dyspnoea (n = 4), hypothyroidism (n = 5) and pericarditis (n = 4). CONCLUSION: Radiotherapy dose may affect local control and the presence of PNI should be considered as an adverse prognostic factor. TACC irradiation conferred good local control rates, when comparing these results with historical series.

Extended surgery for T4 lung cancer: a 30 years' experience.

T4 non-small cell lung carcinomas (NSCLC) were deemed unresectable. Advances in surgery have challenged this dogma. We describe technical aspects and result on superior vena cava (SVC), carinal, thoracic inlet tumor surgeries, and resection under cardiopulmonary bypass (CPB). SVC reconstruction requires hemodynamic control to reverse SVC clamping cerebral effects and excellent cephalic venous bed patency. Among 50 SVC resections, including 25 carinal pneumonectomies, post-operative mortality rate was 8%. In the N0-N1 group, 5- and 10-year survival rates were 46.6 and 37.7%, respectively. Right carinal pneumonectomy was performed through right thoracotomy. Sternotomy was favored for left carinal pneumonectomy or carinal resection alone. Among 138 carinal resections, including eight right upper lobectomies, 123 right pneumonectomies, four left pneumonectomies, and three isolated carinal resections, the post-operative mortality rate was 9.4%. In the N0-N1 patients, 5-year survival rate was 47%. 191 patients underwent resections of thoracic inlet tumors through a transclavicular cervicothoracic anterior approach combined in 63 patients with a posterior midline incision for limited spine invasion. In N0-N1 group, 5- and 10-year survival rates were 41.5 and 29.7%, respectively. CPB allowed resection of tumors invading the heart or great vessels in 13 patients. R0 resection and post-operative mortality rate were 94.4 and 5.5%, respectively. In this series of 388 T4 NSCLC, the post-operative mortality rate was 4%. In the R0 and N0-N1 groups, the 5-year survival rates were 44 and 41%, respectively. Surgical resection of T4 locally advanced NSCLC is worth being performed in selected N0-N1 patients, provided that a radical resection is expected.

Bronchial Paraganglioma with SDHB Deficiency.

Though most paragangliomas arise as sporadic tumors, the recent advantages in the genetic screening revealed that about 30 % of paragangliomas are linked to hereditary mutations, such as those involving SDH genes. A 22-year-old woman carrying a left main bronchus tumor underwent surgery in our institution. Her past medical history included a GIST without KIT or PDGFRA mutation. The histological examination revealed a nested proliferation of medium-sized cells expressing neuroendocrine markers (chromogranin A and synaptophysin). The neoplastic cells failed to express SDHB gene product. These findings led us to the final diagnosis of bronchial paraganglioma in the setting of Carney-Stratakis syndrome. Bronchial paragangliomas are exceedingly rare tumors with polymorphous clinical presentation, and usually benign clinical course. Though most paragangliomas are sporadic, some tumors are associated with specific hereditary disease, especially those occurring in young patients or in combination with other neoplasms.

Inactivation of p53 Is Sufficient to Induce Development of Pulmonary Hypertension in Rats.

OBJECTIVE: Pulmonary artery smooth muscle cells (PA-SMCs) in pulmonary arterial hypertension (PAH) show similarities to cancer cells. Due to the growth-suppressive and pro-apoptotic effects of p53 and its inactivation in cancer, we hypothesized that the p53 pathway could be altered in PAH. We therefore explored the involvement of p53 in the monocrotaline (MCT) rat model of pulmonary hypertension (PH) and the pathophysiological consequences of p53 inactivation in response to animal treatment with pifithrin-α (PFT, an inhibitor of p53 activity). METHODS AND RESULTS: PH development was assessed by pulmonary arterial pressure, right ventricular hypertrophy and arterial wall thickness. The effect of MCT and PFT on lung p53 pathway expression was evaluated by western blot. Fourteen days of daily PFT treatment (2.2 mg/kg/day), similar to a single injection of MCT (60 mg/kg), induced PH and aggravated MCT-induced PH. In the first week after MCT administration and prior to PH development, p53, p21 and MDM2 protein levels were significantly reduced; whereas PFT administration effectively altered the protein level of p53 targets. Anti-apoptotic and pro-proliferative effects of PFT were revealed by TUNEL and MTT assays on cultured human PA-SMCs treated with 50 µM PFT. CONCLUSIONS: Pharmacological inactivation of p53 is sufficient to induce PH with a chronic treatment by PFT, an effect related to its anti-apoptotic and pro-proliferative properties. The p53 pathway was down-regulated during the first week in the rat MCT model. These in vivo experiments implicate the p53 pathway at the initiation stages of PH pathogenesis.

[Surgical treatment of pulmonary arterial hypertension]. / Traitement chirurgical de l'hypertension artérielle pulmonaire.

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a severe disease that has undergone a dramatic improvement in therapeutic management over the past 20 years. Among the new therapeutic options, surgery has the potential to dramatically improve or, in some cases, cure PAH. BACKGROUND: Surgical treatment of PAH includes pulmonary endarterectomy which can cure PAH when the cause is obstruction of the pulmonary arteries by fibrous tissue resulting from pulmonary embolism, by tumours as angiosarcomas, and echinococcus cysts. Transplantation is required in end-stage PAH after failure of medical treatment. Atrial septostomy and Potts procedure are palliative surgical procedures that can delay transplantation. VIEWPOINT: Extracorporeal cardiopulmonary support is the latest surgical improvement, not only as a bridge to transplantation in end-stage PAH but also during recovery after transplantation or pulmonary endarterectomy. CONCLUSIONS: Surgery is part of the therapeutic management of PAH. Dialogue between physicians and surgeons is a prerequisite for any reasoned therapeutic decision.

Enhancement of non-coronary collateral blood flow from the internal thoracic arteries: the theoretical and practical basis of an alternative method of myocardial blood supply.

Non-coronary collateral blood flow arrives to the heart from mediastinal, bronchial, and pericardial channels. These enter the heart through the pericardial reflections surrounding the pulmonary and systemic veins, as well as from the vasa vasorum of the aorta and the pulmonary artery leading to and from the myocardium. Before the advent of cardiopulmonary bypass surgery, surgical bilateral ligature of the internal thoracic arteries (ITAs) was performed in patients with ischemic heart disease to increase the perfusion pressure within the channels leading to the heart. Nowadays, the occurrence of natural collaterals between coronary and extracardiac arteries including the ITAs, the potential hemodynamic effects of ITA ligation, the potential of ITAs for developing important collateral branches, and the current availability of angiogenic growth factors could pave the way for the development of a new field in cardiovascular research aimed at developing an alternative strategy of myocardial blood supply by means of the surgical and biological enhancement of non-coronary collateral circulation.

Outcome after combined pulmonary endarterectomy and mitral valve replacement.

Concomitant pulmonary endarterectomy and cardiac surgery has rarely been described in the literature. We report a 30-year-old patient who underwent pulmonary endarterectomy and concomitant mitral valve replacement associated with closure of a patent foramen ovale.

Surgical treatment of celiac artery aneurysm associated with median arcuate ligament.

Celiac artery aneurysms are rare but potentially fatal because of the risk of rupture. Atherosclerosis and fibrous dysplasia are the two most common etiologies. Median arcuate ligament compression of the celiac artery is common but usually asymptomatic. We report three cases of post-stenotic celiac artery aneurysm with median arcuate ligament compression admitted to our hospital over the past two years. Although the incidence is rare with only 8 cases reported in the literature, a median arcuate ligament may have a role in the development of celiac artery aneurysms and its presence can influence the surgical strategy.

[Postembolic pulmonary hypertension]. / Hypertension pulmonaire postembolique.

INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease characterized by the persistence of thromboemboli obstructing the pulmonary arteries as an organized tissue. The consequence is an increase in pulmonary vascular resistance resulting in pulmonary hypertension (PH) and progressive right heart failure. BACKGROUND: It is difficult to recognize the postembolic nature of PH because there is no known history of thromboembolic disease in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the ventilation-perfusion scanning. When CTEPH is suspected, pulmonary angiography and high-resolution CT scan are required to establish the diagnosis and to assess the operability. Pulmonary angiography is always performed in conjunction with a diagnostic right heart catheterization, which is required to confirm the diagnosis of PH and to determine the degree of hemodynamic impairement. If there is a good correlation between the pulmonary vascular resistance and the anatomical obstruction, pulmonary endarterectomy (PEA) must be proposed. Otherwise, vasodilator and antiproliferative treatments and lung transplantation represent interesting alternatives. VIEWPOINT AND CONCLUSION: PEA remains the treatment of choice for eligible patients. Nevertheless, there is a need to conduct randomized trials to assess the efficacy of novel medical therapies in some situations: (1) in inoperable CTEPH due to distal lesions, (2) before PEA (therapeutic bridge) in patients who are considered "high risk" due to extremely poor hemodynamics, (3) in patients with persistent pulmonary hypertension after surgery.

Surgical management of mediastinal goiters: when is a sternotomy required?

OBJECTIVE: Mediastinal goiters are frequently diagnosed, particularly in the elderly population. However, factors associated with an increased risk of median sternotomy have not been analyzed systematically. METHODS: Between 1980 and 2004, a total of 185 patients underwent surgery for mediastinal goiters in our institution. There were 126 women and 59 men with a median age of 68 years (range 24 to 94 years). The goiters were left-sided in 77 patients, right-sided in 69 patients, and bilateral in 39 patients. RESULTS: Clinical presentation was mainly dyspnea (37 %), palpation of a cervical mass (35 %), superior vena cava syndrome (5 %), dysphagia (4 %) and dysphonia (4 %). Goiters measured between 5 and 23 cm (median 10 cm) and were prevascular (38 %), retrovascular and paratracheal (33 %), and retrotracheal (27 %). Aberrant intrathoracic goiters were observed in 4 patients (2 %). The large majority of goiters could be removed transcervically, regardless of the location and extension of the goiters. A sternotomy was required in 13 patients (6 %), mainly because of recurrent goiter ( P = 0.1), ectopic goiter ( P < 0.001), or invasive carcinoma ( P < 0.001). Superior vena cava syndrome, emergent airway compression, dysphagia, retrotracheal goiter, or crossover goiters were not found to be associated with an increased risk of sternotomy. One patient (0.5 %) died postoperatively from massive intraoperative carcinomatous pulmonary emboli. Histology demonstrated a thyroid carcinoma in 18 patients (10 %). CONCLUSIONS: Surgery for mediastinal goiters should always be considered, even in elderly patients because of the high risk of tracheal compression and the low morbidity of the surgery. Most mediastinal goiters are benign and can be removed through a cervical approach. Sternotomy should only be performed in cases of previous cervical thyroidectomy, invasive carcinoma, or ectopic goiter.

[Surgical treatment of chronic thromboembolic pulmonary hypertension]. / Traitement chirurgical de la maladie thromboembolique pulmonaire chronique.

Chronic thromboembolic pulmonary hypertension is a condition that has long remained in the shadows, a kind of orphan disease, because of the lack of any curative treatment. The renewal of interest by pulmonary specialists, cardiologists and thoracic surgeon is due to the development over the past 20 years of major new treatments: lung transplantation, continuous prostacyclin infusion, and pulmonary endarterectomy, in chronological order. Most patients with postembolic pulmonary arterial hypertension (PEPAH) in a sufficiently proximal location can benefit from curative surgical treatment by bilateral endarterectomy of the pulmonary arteries. This complex surgery, performed under deep hypothermic circulatory arrest, clears out the pulmonary vascular bed down through its subsegmental branches and results in a frank reduction in pulmonary vascular resistance and normalization of cardiopulmonary function. It is a curative procedure with a perioperative mortality rate less than 7% and a definitive result, unlike pulmonary and cardiopulmonary transplantation, which have a postoperative mortality rate of 20% and a 5-year survival rate of 50%. It is difficult to recognize the postembolic nature of pulmonary hypertension because there is no known history of venous thrombosis or embolic phenomena in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the radioisotopic ventilation-perfusion scanning. To be accessible to endarterectomy, lesions must involve the main, lobar, or segmental arteries. When conducted by experienced operators according to specific protocols, pulmonary (frontal and lateral views of each lung) and multislice CT angiography optimize assessment of the lesion site. When the pulmonary vascular resistance evaluated by catheterization is correlated with the anatomical obstruction visible on the images, pulmonary endarterectomy has a mortality rate below 4% and offers the patient a substantial chance to regain normal cardiorespiratory function. In cases of pulmonary arterial hypertension due to older embolisms, major arteriolitis occurs in the nonobstructed areas and aggravates the pulmonary hypertension, which may become suprasystemic. The endarterectomy mortality rate is then higher, and in specific cases justifies preoperative medical treatment. Pulmonary or cardiopulmonary transplantation is indicated in this disease only when the lesions are too distal and thus inaccessible to endarterectomy.