Ruptured Idiopathic Pulmonary Artery Aneurysm: Unusual Case of Hemothorax Treated by Selective Embolization

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1 Ruptured Idiopathic Pulmonary Artery Aneurysm: Unusual Case of Hemothorax Treated by Selective Embolization KK Haridas, George Mathew Neeraakal, Sreekant Moorthy, Nirmal Kumar Prabhu, Viveka Kumar Departments of Cardiology and Radiology, Amrita Institute of Medical Sciences and Research Centre, Cochin Aneurysm of the peripheral pulmonary arteries is rare. Rupture of pulmonary artery aneurysms manifesting as recurrent hemoptysis wit exsanguination is well recognized. We report the case of a young woman who presented with massive hemothorax and shock at the sixth month o pregnancy due to a ruptured lingular artery aneurysm. She was treated with selective coil embolization of the lingular artery to achiev hemostasis. Subsequently, clot evacuation from the pleural space was done. This case is reported for its unsuspected presentation, rarity and to highlight th use of catheter coil embolization to achieve control of bleeding and exclusion of the aneurysm from the pulmonary circulation. (Indian Heart 2001; 53: ) Key Words: Pulmonary artery aneurysm, Hemothorax, Coil embolization Unsuspected hemothorax usually occurs in inflammatory or malignant conditions of the lung and pleura, following trauma or vascular bleeding int the pleural space. Arteriovenous malformations are well recognized causes of hemothorax. Ruptured aortic, intercostal and pulmonary arter aneurysms can potentially present with hemothorax. We report the case of an idiopathic pulmonary artery aneurysm in a young, pregnant woma presenting as hemothorax and shock. She was managed successfully by coil embolization. Case Report A 27-year-old woman who was 24 weeks pregnant, was hospitalized with sudden onset of left-sided chest pain and shock. Clinical assessmen revealed features of shock, low hematocrit, mediastinal shift to the right and absent air entry over the left side of the chest. Chest X-ray revealed massive pleural collection on the left side with mediastinal shift to the right (Fig. 1a). A diagnostic pleural aspiration showed hemorrhagic fluid. A emergency spiral CT scan with intravenous contrast revealed evidence of a massive left-sided hemothorax with collapsed left lung and a contrast enhancing discrete subpleural mass lesion in the region of the lingular segment of the left lung, suggesting a vascular malformation or a lingula

2 artery aneurys (Fig. 1b). A diagnostic venous digital subtraction angiography (DSA) with fetal shielding performed on an emergency basis reveale a discrete subpleural aneurysm of the lingular branch of the left pulmonary artery (Figs 2a and b). After correcting the shock with colloi replacement and inotropes, coil embolization of the lingular artery was planned to achieve hemostasis. The left pulmonary artery was selectively cannulated with a 6 F multipurpose end-hole catheter (Cook MPB). The pulmonary artery pressures an pulmonary capillary wedge pressures were low normal. Using a Terumo 0.035" guidewire the lingular artery was cannulated. The wire wa exchanged for a 0.018" floppy-tip extra support coronary wire for deep wiring of the peripheral segment of the lingular artery. A selectiv angiogram was performed to delineate the lingular artery. Two 4 6 mm embolization coils (Cook) were delivered proximal to the aneurysm. A additional 3 5 mm coil was placed in a minor proximal branch which skirted the aneurysm. Following coil embolization, the aneurysm wa excluded from the left pulmonary arterial circulation (Fig. 3a). The patient s hematocrit and hemodynamic condition remained stable. A left pleural drain was placed, following which there was partial relief of the hemothorax. However, nonexpansion of the left lung warranted subsequent left thoracotomy for clot evacuation. During thoracotomy, an infarcted left lingular segment was observed which was resected fo pathological studies. Periprocedural blood culture was sterile. The patient had fetal loss which needed evacuation on the fifth day post procedure Maternal recovery was uneventful with complete expansion of the left lung (Fig. 3b). She remains well on one-month follow-up.

3 Fig. 1. (a) Chest X-ray showing massive hemothorax on the left side. Fig. 2. (a) Nonselective venous DSA shows collapsed left lung (upper and (b) Spiral CT scan picture shows hemothorax with a collapsed left lung and an enhancing vascular lesion suggestive of the aneurysm (arrow). lower arrows) with the aneurysm (middle arrow). (b) On the right side, selective left pulmonary artery angiogram shows the aneurysm (arrow) with the feeder vessel. Pathology: (Figs 4a and b) Gross examination of the lung revealed a thin-walled aneurysm cm with an infarcted adjacent lung. There was luminal thrombus. Microscopy revealed a true thin-walled aneurysm lined by the three arterial layers. There was mild fibrointimal hyperplasia. There was no evidenc of any inflammatory cell response in the wall or adjacent lung.

4 Fig. 3a. DSA showing the final result after coil embolization. Fig. 3b. Chest X-ray showing the fully expanded lungs after thoracotomy and clot removal. Arrows show the coils. Fig. 4. Histology of the aneurysm. (a) Low-power view showing arrows pointing to the intima (upper) and adjacent lung. (b) High-power view showing fibrointimal hyperplasia. Discussion Pulmonary artery aneurysm was first described by Churton. 1 Aneurysms involving the central and proximal pulmonary arteries can occur i patients with congenital heart disease and after surgical correction for various heart diseases. Inflammatory disease states and arteritis ca produce multiple aneurysms of the branch pulmonary arteries. 2 In Takayasu s arteritis, multiple aneurysms involving the pulmonary arteries wit

5 or without stenosis reflect the inflammatory nature of this condition. 2 Mycotic aneurysms in the branch pulmonary arteries can follow septi embolism from the heart or venous system. 3 5 These may be isolated or multiple. Rupture of these aneurysms can result in fatal hemoptysis an exsanguination. 6 Our patient did not have any previous history of sepsis and her periprocedural blood cultures were sterile. In the setting o pregnancy, the sudden onset of chest pain with hemothorax pointed to a vascular bleed. Hereditary pulmonary telangiectasia is known to ruptur during pregnancy and can result in hemoptysis or rarely hemothorax. 7,8 Conditions such as pulmonary embolism rarely produce hemorrhagic shoc although nonhemorrhagic shock may occur, which is difficult to differentiate from the former. The source of the bleed in our patient was no evident until contrast CT scan was performed. Conventionally, the treatment for ruptured or leaking pulmonary aneurysms has been surgical. Recently, interventional treatment has made rapi strides in the management of intracranial and peripheral bleeds The hemodynamic state of our patient carried a high risk for genera anesthesia. Moreover, having diagnosed a bleeding subpleural aneurysm there was a genuine risk in performing a thoracotomy. The bleed coul have been temporarily tamponaded by a tension hemothorax. Sudden release of intrapleural pressure could potentially be associated with the ris of exsanguination due to rebleeding. Therefore, a catheter-based procedure to achieve exclusion of the aneurysm from the pulmonary arteria circulation seemed the most attractive option in this patient. If done sufficiently early, the simple procedure of placement of a chest tube may hav enabled evacuation of the blood and resulted in lung expansion without a thoracotomy for clot evacuation. Although fibrinolytics have been used to dissolve and drain pleural clots, in this situation there was a chance of resumption of bleeding from th communication between the aneurysm and the pleura. Catheter-based thrombo-occlusive treatment for a ruptured aneurysm can be aimed a thrombosing the aneurysm itself by deploying thrombogenic material into it or excluding the aneurysm by occluding the entry and exit points o the vessel from it. In our patient, the location of the aneurysm was very peripheral in the lung parenchyma and justified the proposal of occludin only the entry point into the aneurysm to exclude it from the phasic pulmonary arterial pressure head. Subsequent clotting of the aneurysm woul protect leakage from the less pulsatile and lower pulmonary venous pressures. This was reconfirmed by the absence of ongoing bleeding at th time of thoracotomy. We also achieved the semantic satisfaction of placing less thrombogenic material into the body by targeting the feede branch into the aneurysm rather than packing the aneurysm itself with coils. This case demonstrates that ruptured idiopathic subpleural aneurysm of peripheral pulmonary arterial branches can rarely present as hemothora with shock. This can be effectively managed by catheter-based techniques. Further experience in this field will be needed to assess the long-term efficacy and potential limitations of catheterbased therapy for bleeding pulmonary artery aneurysms. Correspondence: Dr KK Haridas, Chairman, Department of Cardiology, Amrita Institute of Medical Sciences and Research Centre, Amrita Lane, Elamakkara, PO Cochin [email protected] References

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