Pulmonary Artery Interventions: An Overview

1. Pulmonary Artery Interventions: An Overview Speaker int. 李冠賢 Supervisor Dr. 郭雪梨 VS. 鍾達榮 RadioGraphics 2005; 25:1653–1667

2. Pulmonary Embolism • The general mortality rate for massive pulmonary embolismwith resultant systemic shock is approximately 30%. • When PE occurs in a patient with underlyingcardiopulmonary disease, it is often associated with right ventriculardysfunctionandcompromised hemodynamics of the cardiopulmonarysystem and, thus, requires more aggressive treatment than anticoagulation. • Medical thrombolysis combined with anticoagulationis the established standard treatmentfor massive and/or life-threateningpulmonary embolism.

3. Pulmonary Embolism Patients with contraindications to thrombolytic drugs…. • Percutaneous catheter-based treatmentis a possible alternative to surgical embolectomy.

4. Pulmonary Embolism Massive pulmonary embolism in a 65-year-old man. /p catheter-based thrombolysis performed by using streptokinase Reestablished perfusion Multiple filling defects • Intra–pulmonary arterial infusion of thrombolytic drugs accelerates clot lysis and hastens the reestablishment of normal pulmonary artery circulation.

5. Pulmonary Artery Stenosis • Intravascular stent implantation has become the first-line treatmentfor pulmonary artery stenosis that occurs as a complicationof a cardiac anomaly and causes right ventricular outflow obstruction. • Percutaneous transluminal balloon angioplasty, performedbecause of concerns about a potential mismatch between stentand blood vessel size after somatic growth and about the long-termsafety of metallic stents in young children, also has been successful.

6. Pulmonary Artery Stenosis • Pulmonary artery stenosis in adults is encountered mainly inpatients with pulmonary vasculitis and rarely is associatedwith other conditions. Patients with systemicvasculitis such as that in Behçet disease or Takayasuarteritis have been reported to have pulmonary arterial involvement,with consequent aneurysms, pseudoaneurysms, and stenoses. • Pulmonary artery stenosis may cause hemoptysis because of the development of systemic hypervascularization.

7. Pulmonary Artery Stenosis Massive hemoptysis in a 50-year-old woman with Takayasu arteritis and systemic hypervascularization of the upper lobe of the right lung depicted at aortography. Enlarged atrial artery branch Embolization of the atrial artery with n-butyl-cyanoacrylate. Supplying collateral flow to the right pulmonary artery A stenosis of the right pulmonary artery Right coronary artery That was subsequently treated with balloon angioplasty

8. Pulmonary Artery Stenosis Massive hemoptysis in a 50-year-old woman with Takayasu arteritis and systemic hypervascularization of the upper lobe of the right lung depicted at aortography. 13 years later Persistent occlusion of the atrial artery Patency of the right coronary artery No residual stenosis in the right pulmonary artery

9. Pulmonary Artery Stenosis Incorrect diagnosis • In patientswith progressive dyspnea and elevation of PApressure, the finding of unmatched segmental perfusion defectsof the lungs frequently has led to an incorrect diagnosis ofchronic thromboembolic disease. • The recognition of isolatedpulmonary artery stenosis, particularly in patients with a previousdiagnosis of chronic thromboembolic disease, radically changesthe management plan. Angioplasty may be performed toredistribute pulmonary arterial flow toward low-resistance territories,reduce right ventricular pressure, and alleviate symptoms.

10. Pulmonary Artery Stenosis Chronic thromboembolic disease in a 70-year-old woman with equal high pulmonary artery and arterial pressures. Middle lobe of the right lung Poststenotic aneurysm Marked stenosis of the pulmonary artery in the middle lobe of the right lung and a poststenotic aneurysm Angiogram shows inflation of the balloon during angioplasty Marked redistribution of blood flow throughout the middle lobe of the lung

11. Pulmonary Artery Pseudoaneurysms • Rare condition, which are associated withtrauma (from use of a Swan-Ganz or Cournand catheter), congenitalheart disease, necrotic cavitary lung carcinoma, or other factors. • Theprimary symptom: hemoptysis,which is often massive. • Several potential causes of hemoptysishave been described: Necrotizing pneumonia, bacterialendocarditis, mucormycosis, tuberculosis, and vasculitis (asin Behçet disease). • Because of the risk of pseudoaneurysm enlargementand rupture, which leads to death in approximately 50% of patients,prompt therapy is required. Percutaneous embolization isa minimally invasive alternative to open thoracotomy and resectionof both the pseudoaneurysm and the affected lobe.

12. Pulmonary Artery Pseudoaneurysms • Pseudoaneurysm Due to Lung Cancer • Massive hemoptysis in patients with carcinoma of the lung canbe successfully managed with transcatheter embolization of eitherthe bronchial arteries or collateral arteries to the affectedlung. • Significant bleeding from the pulmonary artery israre and usually is secondary to an erosive pulmonary arterypseudoaneurysm associated with a necrotic cavitary lesion.

13. Pseudoaneurysm Due to Lung Cancer Carcinoma of the lung in a 50-year-old man Cavitated perihilar mass with nodular enhancement inside the cavity Upper-lobe consolidation and central excavation in the right lung.

14. Pseudoaneurysm Due to Lung Cancer Carcinoma of the lung in a 50-year-old man Complete occlusion of the pseudoaneurysm. Reduction of blood flow in the arterial branches to the lower and middle lobes with coil embolization, and packing of the pseudoaneurysm (arrow) with n-butyl-cyanoacrylate and coils.

15. Pulmonary Artery Pseudoaneurysms Pseudoaneurysm from Manipulation of a Swan-Ganz Catheter Rupture of the pulmonary artery or one of its branches during right heart catheterization is a rare complication encountered in 0.001%–0.5% of cases. The mortality rate associated with pulmonary artery rupture, however, is as high as 50%.Sudden hemoptysis or hemothorax may result and requires emergent management. Delayed hemoptysis related to a pseudoaneurysm also has been reported. To correct these complications, embolization may be performed with n-butyl-cyanoacrylate and/or metal coils

16. Pseudoaneurysm from Manipulation of a Swan-Ganz Catheter Cardiac failure due to pulmonary artery rupture in an 89-year-old man after Swan-Ganz catheterization Nodule

17. Pseudoaneurysm from Manipulation of a Swan-Ganz Catheter Cardiac failure due to pulmonary artery rupture in an 89-year-old man after Swan-Ganz catheterization Pseudoaneurysm Complete occlusion of the pseudoaneurysm (arrow) with coils.

18. Pulmonary Artery Pseudoaneurysms Pseudoaneurysm in Behçet Disease • Behçet disease is a chronic, systemic collagen-vascular disorder of unknown origin that mainly affects young men from Mediterranean(地中海) countries, the Middle East, or Japan. • Current diagnostic criteria for Behçet disease consist of the presence of recurrent oral ulcerations plus two additional criteria including recurrent genital ulcerations, eye lesions, skin lesions, and positive pathergy tests. • Pulmonary involvement, which is present in 5% of affected patients, occurs in a late stage of the disease. The presence of a pulmonary artery pseudoaneurysm suggests a poor prognosis, with massive hemoptysis being associated with a high mortality rate. The apparent pulmonary artery aneurysms in patients with Behçet disease are pseudoaneurysms that arise as complications of vasculitis and transmural necrosis.

19. Pseudoaneurysm in Behçet Disease Large pulmonary artery pseudoaneurysm in a 28-year-old man with Behçet disease A large left pulmonary artery pseudoaneurysm Embolization of the pseudoaneurysm with multiple coils

20. Pulmonary Artery Pseudoaneurysms Pseudoaneurysm in Behçet Disease • In most patients, the pseudoaneurysms are multiple, bilateral, saccular, and partially or completely thrombosed; the pulmonary arteries distal to the pseudoaneurysms also are thrombosed. • Selective transcatheter embolization is a valuable alternative to surgery. The technique of embolization varies from one center to another, with some interventional radiologists using coils while others favor acrylic glue.

21. Pseudoaneurysm in Behçet Disease Bilateral pulmonary artery pseudoaneurysms in a 34-year-old man with Behçet disease. Bilateral pseudoaneurysms (arrow) and the occlusion of distal pulmonary artery branches

22. Pseudoaneurysm in Behçet Disease Bilateral pulmonary artery pseudoaneurysms in a 34-year-old man with Behçet disease. Balloon-assisted technique

23. Pulmonary Artery Aneurysms • Rare condition • The causes of these lesions arenot well known, but pulmonary artery aneurysms may be congenitalor acquired in origin. Pulmonary hypertension is reputed tobe an important factor in the pathogenesis of pulmonary arteryaneurysms. Themajor complication of pulmonary artery aneurysm is hemoptysis,which results from rupture and which is frequently fatal. • Clear guidelines for treatment do not exist, but treatment is recommendedin the presence of a progressive increase in size. Transcatheterembolization with steel coils is an effective and safe methodof preventing aneurysm rupture.

24. Pulmonary Artery Aneurysms Pulmonary artery aneurysm in a 78-year-old woman with a chronic cough. 3-cm-diameter aneurysm in the apical pulmonary artery of the culmen Increasedin the size of the nodule

25. Pulmonary Artery Aneurysms Pulmonary artery aneurysm in a 78-year-old woman with a chronic cough. Selective embolization of the arterial supply to the aneurysm with the use of detachable microcoils

26. Pulmonary Artery Aneurysms Pulmonary artery aneurysm in a 78-year-old woman with a chronic cough. Complete exclusion of the aneurysm, with patency maintained in the distal pulmonary artery branches

27. Pulmonary Arteriovenous Malformations • Most commonly congenital in origin. • From 60% to 90% of patients with pulmonary arteriovenous malformations have hereditary hemorrhagic telangiectasia, which is also known as Rendu-Osler-Weber syndrome; however, abnormal communication between blood vessels of the lung also may be found in a variety of acquired conditions.

28. Pulmonary Arteriovenous Malformations Simple arteriovenous malformation in a 43-year-old man with hereditary hemorrhagic telangiectasia. Feeding artery Vein Sac Complete occlusion of the malformation with coils Simple arteriovenous malformation of the pulmonary lingula

29. Pulmonary Arteriovenous Malformations • Pulmonary arteriovenous malformations provide direct capillary-free communications between the pulmonary and the systemic circulation, with three main clinical consequences: (a) Pulmonary arterial blood passing through these right-to-left shunts cannot be oxygenated, a situation that may lead tohypoxemia. (b) The absence of a normal filtering capillary bed allows particulate material (air bubbles or clots) to reach the systemic circulation directly (paradoxical embolism), with potential clinical sequelae in the cerebral circulation (transient ischemic attack, stroke, brain abscess). (c) These abnormal vessels, particularly in pregnant women, may rupture into the bronchus (hemoptysis) or the pleural cavity (hemothorax).

30. Pulmonary Arteriovenous Malformations Diffuse arteriovenous malformations in a 28-year-old woman with hereditary hemorrhagic telangiectasia and severe hypoxemia. Small malformations in subsegmental branches (arrows) of all the segmental pulmonary arteries

31. Endovascular Catheter-based Biopsy • Filling defects in the main pulmonary artery or branches are usually associated with thromboembolic disease. • When no symptomatic improvement is obtained despite anticoagulation therapy, or when the thrombus enhances at CT after the administration of iodinated contrast material or produces enlargement of the artery, evidence for another diagnosis (eg, that of angiosarcoma) may be sought at endovascular biopsy. • Various devices that are used for right or left ventricular biopsy also can be used to perform endovascular biopsy in the pulmonary arteries.

32. Endovascular Catheter-based Biopsy Cardiac insufficiency in a 30-year-old woman with no history of pulmonary embolism or deep venous thrombosis and with normal pulmonary artery pressure at angiography and normal flow in lower-limb vessels at Doppler US. Filling defect in an artery (arrow) in the lower lobe of the left lung Complete obstruction of the right pulmonary artery (not shown) also was found. Confirm the presence of the filling defect by selective pulmonary angiogram An organized thrombus was found at pathologic analysis, and the final diagnosis was thromboembolic disease. An endovascular biopsy was performed in the suspicious arterial segment

33. Percutaneous Retrieval of Foreign Bodies Percutaneous retrieval of intravascular foreign bodies is now a standard treatment. In the majority of cases, the procedure involves retrieval of catheter fragments from the superior vena cava, right side of the heart, or pulmonary artery. The standard technique involves the use of a catheter loop with a wire snare. Fragments of flexible catheters tend to migrate to the distal part of the left pulmonary artery, where they can be snared easily. A pigtail catheter also may be used to dislodge a long fragment of a catheter in a remote vessel by rotating and retracting the fragment to a position where it can be snared. Complications are rare if the procedure is performed by an experienced interventionalist.

34. Percutaneous Retrieval of Foreign Bodies Retrieval of a catheter fragment in a 56-year-old man, 3 months after venous catheter implantation for chemotherapy of colorectal cancer. A pigtail catheter Snaring A long fragment of the venous catheter lodged in the main pulmonary artery

35. Percutaneous Retrieval of Foreign Bodies Retrieval of a catheter fragment in a 56-year-old man, 3 months after venous catheter implantation for chemotherapy of colorectal cancer. Emergence of the fragment at the femoral puncture site Extraction

36. Other Techniques • Embolization for Flow RedistributionPulmonary artery flow redistribution by means of embolization has been proposed as a method for improving hypoxemia in patients with hepatopulmonary syndrome or diffuse arteriovenous malformations. However, after permanent lobar artery occlusion, even of only the most affected lobes, patients may be at risk of hemoptysis. • Angioscopy and Intravascular USIntravascular ultrasonography (US) may be helpful for precise assessment of peripheral pulmonary artery stenosis before angioplasty. In patients with chronic thromboembolic disease, angioscopy and intravascular US are useful to characterize thrombi and related pulmonary artery lesions. Pulmonary embolism may be differentiated from primary pulmonary hypertension with the use of percutaneous pulmonary angioscopy and biopsy. • Temporary Occlusion of the Pulmonary ArteryIn preparation for pulmonary resection, pressure in the right heart and pulmonary circulation, pulmonary ventilation, and partial pressure of the blood gases are sometimes measured before and after unilateral occlusion of the pulmonary artery. These parameters may be useful for predicting early postoperative morbidity and mortality. Severe pulmonary hemorrhage after cardiopulmonary surgery also may be treated with temporary balloon occlusion.

37. Conclusions • A close collaboration between interventional radiologists, pulmonologists, oncologists, anesthesiologists, and critical care physicians is mandatory for optimal patient management with full therapeutic options. Nowadays, the percutaneous catheter-based techniques used for emergent embolization of pulmonary artery pseudoaneurysms or pulmonary arteriovenous malformations, foreign body retrieval, and thrombolysis or fragmentation of massive pulmonary emboli are effective and safe alternatives to open surgery. • Interventional radiologists should undergo training in pulmonary arterial interventions to ensure the greatest benefits to patients from these procedures.

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