Pulmonary Microvascular Disease

Transcription

1 Pulmonary Microvascular Disease CS Restrepo M.D. (UT Health San Antonio, TX) D. Vargas M.D. (University of Colorado in Denver, CO) Saboo M.D. (UT Southwestern, Dallas TX) A.J. Baxi M.D. (UT Health San Antonio, TX Disclosure: Nothing to disclose

2 Introduction The pulmonary microvasculature (arterioles, venules and capillaries) can be affected in numerous conditions. Congenital malformations, inflammatory conditions (vasculitis), idiopathic, proliferative, neoplastic, thrombotic and non-thrombotic embolisms can affect the small vessels of the lung with significant morbidity and mortality. Overview Small vessel vasculitis Hepatopulmonary syndrome Pulmonary veno-occlusive disease Pulmonary capillary hemangiomatosis Pulmonary lymphangiectasia Hereditary hemorrhagic telangiectasia Intravascular metastases Lymphangitic carcinomatosis Non-thrombotic pulmonary embolism

3 Small vessel vasculitis (SVV) Lung involvement is most commonly seen with the primary, idiopathic, small-vessel, or ANCA associated vasculitides; Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. However, primary, idiopathic medium and large-vessel vasculitis, primary immune complex mediated vasculitis, and secondary vasculitis are all capable of presenting with lung involvement. Imaging spectrum is wide, from extensive air-space consolidation to airway involvement, pulmonary nodules and cavitation. Hansell DM. Radiology 2002;225:

4 Microscopic polyangiitis (MPA) ANCA vasculitis in a 63 year old female with hemoptysis. CT shows multifocal parenchymal opacities with airspace consolidation in the lower lobes.

5 Eosinophilic granulomatosis with polyangiitis (EGPA) Churg-Strauss syndrome in a 48 y/o male with hystory of asthma and nasal polyposis. Graoundglass and patchy consolidation are noted in the bilateral upper lobes.

6 Granulomatosis with polyangiitis (GPA) Granulomatosis with polyangiitis (Wegener s ) in a 57 y/o male with cough and hemoptysis. CT shows cavitary and non-cavitary nodular opacities.

7 Hepatopulmonary syndrome (HPS) Clinical syndrome characterized by the triad of hypoxemisa caused by intrapulmonary vascular dilations (IPVDs) in the setting of chronic liver disease, portal hypertension, or congenital portosystemic shunts. Prevalence: 25 % of patients with chronic liver disease Pathopysiology: Chronic liver disease increases the circulatory level of nitric oxide (NO) and endothelin-1 (ET-1), potent pulmonary vasodilators. Pathology: Gross dilation of the pulmonary capillary vessels with an absolute increase in the number of capillaries. Physiology: Ventilation-Perfusion (V/Q) mismatch, Diffusion- Perfusion impairment, and anatomic shunt. Only effective treatment is liver transplantation.

8 Imaging findings in HPS Chest radiograph may reveal increased interstitial markings due to increased IPVDs CT angiography: Most significant imaging findings is the presence of IPVDs and include: - Dilated peripheral subpleural pulmonary vessels that do not taper normally and extend to the pleural surface (most common finding, 85%) - Vessels with increased pulmonary artery to bronchus ratio - Small peripheral arteriovenous malformations (rare15%) Nuclear medicine: Tc99m MAA (micro-aggregated albumin) may show uptake in the kidneys or brain secondary to intrapulmonary shunt. Kim YK, Kim Y, Shim SS. RadioGraphics 2009;29(3):

9 Hepatopulmonary syndrome in a 63 y/o cirrhotic male with hypoxemia. CT shows dilated vessels in the lung periphery.

10 Hepatopulmonary Syndrome VQ scan in a 46 y/o male with alcoholic cirrhosis and hypoxemia. Perfusion exam with 99m Tc MAAT demonstrated abnormal uptake within the brain, bilateral kidneys, bowels, spleen and liver. Also noted is thyroid and salivary gland uptake without activity in the stomach, which may related to small amount of free pertechnetate in the blood pool

11 Pulmonary Veno-Occlusive Disease (PVOD) Rare cause of pulmonary hypertension (PH), roughly represent 5%-10% of all cases of idiopathic PH Characterized by occlusion or narrowing of pulmonary veins and venules by collagen-rich fibrous tissue. Alveolar capillaries become dilated and engorged. Capillary proliferation may occur mimicking capillary hemangiomatosis. Most cases are diagnosed in infants or young adults Etiology remains unknown. May be idiopathic or associated with other conditions like HIV, connective tissue disease, sarcoidosis, chemotherapy and bone marrow transplantation. Poor prognosis with median survival <3 years

12 PVOD: Imaging findings Evidence of pulmonary hypertension (RV enlargement etc.) Signs of post-capillary venous hypertension (septal thickening, mosaic attenuation, multiple small nodules, pleural effusion, pericardial effusion) Centrilobular ground-glass opacities Mediastinal lymphadenopathy Normal-sized large pulmonary veins and left atrium Montani D, et al. Eur Respir J 2009;33(1):

13 PVOD in a young female patient with arterial pulmonary hypertension. CECT shows ground-glass opacities, mosaic pattern of lung attenuation, and interlobular septal thickening in addition to enlarged pulmonary arteries.

14 Pulmonary Capillary Hemangiomatosis (PCH) PCH is a rare cause of PH, characterized by extensive proliferation of pulmonary capillaries within alveolar septae, by endothelial cells with no mitotic activity. PCH is clinically and radiographically indistinguishable from PVOD, making microscopic diagnosis essential for diagnosis. Also considered an idiopathic disease although numerous associations have been reported Similar to PVOD prognosis is poor and lung transplantation is the only definitive treatment. Frazier AA, et al. RadioGraphics 2007;27:

15 Pulmonary Capillary Hemangiomatosis 38 y/o male with Pulmonary hypertension 2ary to pulmonary capillary hemangiomatosis; brother also had the same condition. Both received bilateral lung transplant. Explanted lungs confirmed the diagnosis originally made from open lung biopsy.

16 Pulmonary Capillary Hemangiomatosis PCH in a young adult male. CECT reveal lymphadenopathy with prominent peripheral and peribronchovascular lymphatics.

17 Pulmonary Lymphangiectasia Pathologic dilation of pulmonary subpleural, interlobular, perivascular and peribronchial lymphatics 0.5% prevalence in infants who are stillborn or die in the neonatal period Associated with congenital chylothorax and nonimmune hydrops fetalis Poor prognosis before effective mechanical ventilation became available Improvement after the first year of life Barker PM et al. Eur Respir J 2004;24:413 Bellini C et al. Lymphology 2005;38:111

18 Primary Pulmonary Lymphangiectasia Primary pulmonary lymphangiectasia in a 3 week old male with respiratory distress. Chest x ray and CT shows a diffuse interstitial process with interlobular septal thickening.

19 Congenital Lymphangiectasia

20 Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu) Hereditary hemorrhagic telangiectasia is a vascular dysplasia that can involve the lungs, brain upper gastrointestinal tract and liver 5-15% of patients have pulmonary AVM that present as solitary or multiple masses on chest radiographs Most commonly in lower lobes of lung Few patients present a diffuse form of AVM involving every subsegmental artery of at least one lobe, which has higher morbidity and mortality Prevalence of 1:10,000 Autosomal dominant linked to two loci Mutations of ENG, long arm of chromosome 9 (HHT1) Mutations in gene encoding for activan A receptor, type II kinase, long arm of chromsome 12 Faughnan ME, et al. CHEST 2000;117:31-38 Pierucci P et al. CHEST 2008;133:

21 Hereditary Hemorrhagic Telangiectasia (HHT) 18-month-old girl with hemoptysis and numerous bilateral arteriovenous malformations.

22 Lymphangitic carcinomatosis More commonly seen in adenocarcinomas Tumoral spread into the lymphatic usually by hematogenous seeding or by retrograde spread from the hilar / mediastinal lymph nodes Both peripheral and central lymphatics may be involved Manifest as nodular and irregular interlobular septal thickening and / or thicken peribronchovascular interstitium Lymphangitic carcinomatosis in a 54 y/o female with lung adenocarcinoma.

23 Intravascular pulmonary metastases Seen in patients with invasive tumors including renal cell, hepatic and pancreatic carcinomas and sarcomas. At CT affected patients show multifocal dilation and beading of peripheral subsegmental pulmonary arteries. Follow-up studies show interval enlargement and proliferation of the intravascular tumor, different from tumor embolism in which the embolized lesion shows no growth. Thrombotic microangiopathy with fibrocellular intimal hyperplasia of small pulmonary arteries and arterioles induced by tumor microemboli can also occur. Ting PT et al. J Can Assoc Radiol 2005;56:214 Franquet T et al. AJR 2002;179:897

24 Intravascular metastases in a 55 y/o male with advanced renal cell carcinpma. CT shows beaded branching tubular lesions in the bilateral lungs.

25 Nonthrombotic Pulmonary Embolism Biologic agents Septic embolism Fat embolism Amniotic fluid embolism Tumor embolism Hydatid embolism Nonbiologic agents Talc embolism Silicone embolism Cement embolism Glue embolism Catheter embolism Gas embolism Lipiodol embolism Bach AG, Restrepo CS, et al. Imaging of nonthrombotic pulmonary embolism: Biological materials, nonbiological materials, and foreign bodies. European Journal of Radiology 2013;82(3):e120-41

26 Fat Embolism Pathophysiology Long bone fractures (1%-20%) Hemoglobinopathies Severe burn Soft tissue injury Diabetes Pancreatitis Neoplasm Imaging Findings Bilateral opacities that resemble pulmonary edema or ARDS 1=3 days after trauma Normal heart size No redistribution No pleural effusion

27 60 y/o F Day 1 Day 3

28 Talc granulomatosis Talc (magnesium silicate) is an insoluble filler used in several oral medications. When oral medications are crushed, dissolved, and injected intravenously, talc particles embolize small pulmonary vessels. The talc particles may then migrate into the pulmonary interstitium, where they induce a foreign-body reaction and fibrosis. Acute injection may result in acute right ventricular failure and shock. Chronic injection can result in emphysema, pulmonary hypertension, and cor pulmonale Nandavaram S et al. Vasc Med Surg 2016;4(3):272

29 Talc embolism in a 29 year old female, with history of IV drug abuse. CECT obtained few days before she died, shows innumerable small pulmonary nodules bilaterally with denser opacities in the posterior aspect of the lungs. Autopsy demonstrated diffuse embolization of pulmonary arteries and arterioles with endovascular talc particles throughout the pulmonary vasculature as well as granulomas.

30 Glue embolization (Glue lung) Embolization therapy of vascular malformations and tumors with cyanoacrilate glue - Isobutyl-2-cyanoacrylate (IBCA) - N-butyl-2-cyanoacrylate (NBCA) Pulmonary embolism is frequent (35%) Usually asymptomatic Respiratory distress, lung infarct, pleural effusion and death can occur Kjellin IB et al. Pediatr Radiol 2000; 30:279 Pelz DM, et al. AJNR 1995;16:19

31 Extensive pulmonary glue embolization during endovascular embolization of a vein of Galen cerebral malformation in a 7 year old male. Patient developed cough and respiratory symptoms during the procedure.

32 Silicone and Oil Pulmonary Embolism Illicit injection for cosmetic purpose Fluid silicone Non-medical silicone (sealant) Respiratory symptoms 15 min-2 days after injection Fever in 50%, ARDS in 60% Death in 20% Peripheral GGO and interlobular septal thickening Peripheral air-space disease in 70% ARDS in a transsexual, 28 y/o patient with SOB two days after gluteal injection of undisclosed amount of silicone. Restrepo CS, et al. J Computer Assist Tomogr 2009;33:233

33 A C B D Silicone pulmonary embolism in two different patients. A an B. 36 y/o female with bilateral silicone gluteal injection three days earlier. C, D. 32 y/o male with pectoralis muscle injection 12 hours earlier.

34 SUMMARY Pulmonary microvascular disease The pulmonary microvasculature (arterioles, venules and capillaries) can be affected in numerous conditions. Congenital malformations, inflammatory conditions (vasculitis), idiopathic, proliferative, neoplastic, thrombotic and non-thrombotic embolisms can affect the small vessels of the lung with significant morbidity and mortality. Overview Small vessel vasculitis Hepatopulmonary syndrome Pulmonary veno-occlusive disease Pulmonary capillary hemangiomatosis Pulmonary lymphangiectasia Hereditary hemorrhagic telangiectasia Intravascular metastases Lymphangitic carcinomatosis Non-thrombotic pulmonary embolism

35 References Hansell DM. Small-vessel disease of the lung: CT-pathologic coreelates.radiology 2002;225: Kim YK, Kim Y, Shim SS. Thoracic complications of liver cirrhosis: radiologic findings. RadioGraphics 2009;29(3): Montani D, et al. pulmonary veno-acclussive disease. Eur Respir J 2009;33(1): Frazier AA, et al. Pulmonary veno-occlussive disease and pulmonary capillary hemangiomatosis.radiographics 2007;27: Faughnan ME, et al. Diffuse pulmonary arteriovenous malformation: characteristics and prognosis. CHEST 2000;117:31-38 Bach AG, Restrepo CS, et al. Imaging of nonthrombotic pulmonary embolism: Biological materials, nonbiological materials, and foreign bodies. European Journal of Radiology 2013;82(3):e Restrepo CS, et al. Silicone pulmonary embolism: report of 10 cases and review of the literature. J Computer Assist Tomogr 2009;33:233 Presenting author contact information: Carlos S. Restrepo M.D. RestrepoC@UTHSCSA.edu