Giant left atrium associated with mitral valve disease may cause morbidity from compression of adjacent structures. We present a case of recurrent left lung collapse caused by massive left atrial enlargement.
A 53-year-old man with a history of mitral valve prolapse and severe mitral regurgitation presented in acute pulmonary edema and required immediate intubation. He had several preceding admissions for heart failure and had become increasingly breathless (New York Heart Association class IV). He had previously declined mitral valve replacement surgery. Echocardiography performed two months ago showed a giant left atrium (13x12 centimeters), normal left ventricular function, severe pulmonary hypertension (pulmonary artery systolic pressure 65 millimeters of mercury), severe mitral and tricuspid regurgitation. He improved with diuretic therapy and was extubated two days later. The following day, he developed respiratory distress and was re-intubated. Chest radiographs showed left lung collapse that re-expanded with positive-pressure ventilation (Figure 1). He developed a second episode of left lung collapse after being weaned off the ventilator and was intubated again. Bronchoscopy revealed pulsatile extrinsic compression of the distal end of the left main bronchus (Figure 2) and the scope could not be passed into the upper or lower lobar bronchi. The patient underwent mitral and tricuspid valve replacement. In addition, left atrial reduction by plicating the posteroinferior wall using a trans-septal approach was done, thereby relieving bronchial compression. There were no further episodes of lung collapse and post-operative bronchoscopy showed patent bronchi. After a post-operative period complicated by brainstem hemorrhage, prolonged intubation requiring tracheostomy and nosocomial infection, he was weaned off the ventilator and successfully rehabilitated. Echocardiography showed reduction of left atrial size to 7x5 centimeters.
Giant left atrium are defined as those measuring more than 8 centimeters in diameter on echocardiography(1) and are typically found in patients with severe mitral regurgitation from rheumatic heart disease or mitral valve prolapse. It causes morbidity by compressing adjacent structures, for example Ortner’s syndrome and esophageal compression. Less common presentations include hyperlucent lung(2) and atelectasis after pericardial decortication(3). However, to the authors’ knowledge, recurrent collapse of the lung has not been reported in the English-language medical literature. In our patient, having established on bronchoscopy that the cause of recurrent lung collapse was due to extrinsic compression by a giant left atrium, we considered the treatment options. Endobronchial stenting was excluded as there were concerns about the risk of perforation into the left atrium with continuing external pressure. In addition, the site of compression was at the distal end of the main bronchus and involved the bifurcation of the lobar bronchi. As such, stenting was not appropriate. We concluded that definitive surgical treatment with prosthetic valve replacement was necessary to correct the underlying pathology. In addition, left atrial reduction surgery, first advocated by Kawazoe(4), was required to reduce bronchial compression.
Recurrent left lung collapse caused by giant left atrium compressing on left main bronchus should be surgically treated with mitral valve replacement and left atrial reduction surgery.
G. Phua, None.