Pulmonic stenosis

INTRODUCTION: Unilateral pulmonary artery stenosis(PAS) is an uncommon but reported complication of many cardiothoracic surgeries. We present an unusual presentation of PAS following the Ross operation that ultimately leads to symptomatic pulmonary hypertension.

CASE PRESENTATION: A 24-year-old Hispanic male was referred to the pulmonary hypertension clinic with symptoms of progressive right heart failure. Two years prior he developed endocarditis complicated by embolic strokes and seizures. He later underwent a Ross operation. The postoperative course was difficult but he had gradual improvement in his functional status. Upon presentation to our clinic he complained of severe dyspnea at approximately 100 yards of ambulation with occasion midsternal chest pain. He denied dyspnea at rest, palpitations, orthopnea, and paroxysmal nocturnal dyspnea. Past medical history was otherwise unremarkable. No other surgeries had been performed. He denied other risk factors for pulmonary hypertension. Physical examination demonstrated normal blood pressure and pulse. His general appearance was only noted for multiple tattoos. There was no jugular venous distention. Lungs were clear. Cardiac exam revealed a normal S1, prominent S2 and a holosystolic murmur along the left sternal border. Extremities were without cyanosis, clubbing, or edema. He had a moderate left hemiplegia. Laboratory data including serologic screening for pulmonary hypertension were unrevealing. Ventilation/Perfusion lung scan showed decreased perfusion to the right lung. Pulmonary angiography (Figure 1) demonstrated stenosis at the level of the distal anastomosis of the pulmonary homograft as well as tight stenosis within the right pulmonary artery. Right heart catheterization (Table 1) demonstrated elevated right ventricular pressures (mean of 31 mm Hg) and less markedly elevated pulmonary artery pressures (mean 25 mm Hg) distal to the main artery stenosis. Pulmonary artery saturation was 65.2%. Also noted was a pressure drop-off across the stenosis of the right pulmonary artery. Pulmonary artery occlusion pressure and cardiac output were normal (8.4L/min). The patient underwent cardiac reoperation for tricuspid valve repair and direct evaluation of the pulmonary artery stenosis. The distal anastomosis on the pulmonary homograft was stenotic. The right pulmonary artery was noted to be severely stenotic. Further dissection revealed the presence of a Prolene suture placed through the proximal right pulmonary artery causing the stenosis. This suture was removed and the artery was successfully dilated to the size of a #10 dilator. The main pulmonary artery at the site of stenosis was enlarged with a Dacron patch. The tricuspid valve was repaired. The postoperative course was uncomplicated and exercise tolerance continues to improve. His limitations due to dyspnea upon exertion have been dramatically decreased with relief of the pulmonary artery stenoses.

DISCUSSIONS: Our case is a unique cause of pulmonary hypertension due to an unreported complication of the Ross operation. Main PAS is a well-recognized complication of placement of a pulmonic homograft. Unilateral stenosis is also a reported complication of lung transplantation, including contralateral PAS following single lung transplantation. Unilateral stenosis has been previously reported with other cardiothoracic surgeries. In our case lung perfusion scanning, pulmonary angiography, and right heart catheterization demonstrated the presence of hemodynamically significant unilateral stenosis in addition to an anastomotic stenosis. A suture as the etiology was surprising. After surgical correction, the patient was able to make expected gains in exercise tolerance. It can be inferred that both areas of stenosis contributed to the patient's symptoms based upon hemodynamic data, intraoperative findings, and post-operative improvement.

CONCLUSION: Pulmonary artery stenosis is an unusual complication of the Ross Procedure. Unilateral pulmonary artery stenosis has not been reported but should be considered when pulmonary hypertension develops after this procedure.

DISCLOSURE: Timothy Mooring, None.

Timothy S. Mooring MD * Victor J. Test MD Scott and White Hospital and Clinics, Temple, TX

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