INTRODUCTION: Bullous disease in which a bulla occupies more than one third of the hemithorax is known as giant bullous emphysema. These bullae are easily distended, are preferentially filled during inspiration, and can compress adjacent normal lung parenchyma without contributing significantly to gas exchange. In these patients, bullectomy can be performed to improve respiratory mechanics and improve dyspnea. We present a patient who had a giant bulla that not only impaired pulmonary function, but also impaired right ventricular filling by mass-effect.
CASE PRESENTATION: A 35 year old male tobacco and marijuana smoker with history of a spontaneous pneumothorax 10 years ago presented to the emergency room with fevers, chills, and dyspnea. A CT of his chest showed bilateral upper lobe bullous emphysema with evidence of consolidation in the left upper lobe. Furthermore, it showed a giant right upper lobe bulla that herniated across the midline, causing shift of cardiomediastinal contents into the left hemithorax. EKG showed right axis deviation, and echocardiogram showed increased thickness of the right ventricular wall and a small pericardial effusion. The patient was treated with a long course of antibiotics and recovered from his acute infection. An outpatient cardiac MRI showed that his giant RUL bulla exerted significant mass-effect on the right ventricle: it caused tubular extrinsic compression, paradoxical motion of the right ventricular wall, and impaired right ventricular filling. Pulmonary function tests showed mild obstruction and significant air trapping (RV = 193% of normal) and the patient continued to have dypsnea on exertion. The patient was referred for video assisted thoracoscopy for bullectomy. After bullectomy, his FEV1 increased by 0.59L (20%) and residual volume decreased by 0.66L (30%) over his preoperative values. Furthermore, his follow-up echocardiogram revealed normal RV size and function.
DISCUSSIONS: Surgical resection for bullous emphysema is generally recommended when the bulla is larger than one third of the hemithorax, when there is significant compression and impairment of adjacent lung tissue, and when the patient has a preoperative FEV1 less than 50% of predicted (1). One case series of 43 patients who underwent resection of giant emphysematous bullae had improved FEV1, RV, and six minute walk test up to three years after surgery (2). Our patient did not have significant obstruction (his preoperative FEV 1 was 86%), but nonetheless, the bulla's remarkable mass effect on his heart was concerning. Direct cardiac compression from bullous lung disease and its long term implications has not been reported. We hypothesized that this patient’s symptoms may have been related to the cardiac compression caused by his bulla and left untreated may have progressed to worsening right heart failure. Bullectomy successfully restored his cardiac function as well as improved his pulmonary status.
CONCLUSION: Giant bullae may not only impair respiratory mechanics, but can also cause cardiac dysfunction via mass effect. When faced with a patient with a giant bulla, cardiac evaluation should be considered and bullectomy may be a good treatment option.
DISCLOSURE: Thanh Huynh, No Financial Disclosure Information; No Product/Research Disclosure Information