Masae Haga

Evaluation of an internal thoracic artery as a coronary artery bypass graft by intercostal duplex scanning ultrasonography

OBJECTIVES Although angiography is often used to determine whether the internal thoracic artery is appropriate as a coronary bypass graft, but use of duplex scanning ultrasonography for this purpose is not yet widespread. METHODS The internal diameter and flow of the internal thoracic artery were measured using intercostal duplex scanning in 100 patients during April 1995. The ultrasonographic device (sonos 2000, Hewlett Packard) used had a linear probe delivering a frequency of 7.5 MHz. Bilateral internal thoracic arteries and their blood flow were imaged clearly in all subjects. Diameter was compared by angiography and duplex scanning ultrasonography in 20 patients. RESULTS The average internal diameter of internal thoracic artery was 2.19 +/- 0.46 mm (right) or 2.13 +/- 0.32 mm (left) in men and 2.05 +/- 0.44 mm (right) or 2.09 +/- 0.42 mm (left) in women. The gender difference was statistically significant (p = 0.05). The maximum systolic blood flow velocity through the internal thoracic artery was 0.85 +/- 0.34 m/s (right) or 0.84 +/- 0.36 m/s (left) in men and 0.87 +/- 0.28 m/s (right) or 0.82 +/- 0.28 m/s (left) in women. The average internal thoracic arterial blood flow (F) was 54.6 +/- 29.0 ml/min (right) or 50.9 +/- 28.8 ml/min (left) in men and 56.8 +/- 38.2 ml/min (right) or 58.2 +/- 33.4 ml/min (left) in women. Duplex scanning ultrasonography using an intercostal approach enables easy imaging of bilateral internal thoracic arteries and visualizes entire internal thoracic artery structure by simply changing the probe position. CONCLUSION Intercostal duplex scanning ultrasonography is thus recommended for reliable evaluation of the internal diameter and blood flow of the internal thoracic artery.

Thoracic aortic aneurysm complicated with severe coronary arterial occlusive disease.

The patient was a 77-year-old female who had been treated medically for angina pectoris since 5 years ago. Expanded aneurysms in the distal aortic arch and in the descending thoracic aorta were seen during follow-up. She presented continuous back-pain at rest along with increasing size of the aneurysms despite antihypertensive therapies after admission. First, two saphenous vein grafts were anastomosed to the left anterior descending artery and obtuse marginal artery under beating heart. Next, the proximal portion of the left subclavian artery was clamped and divided. To this graft, the proximal ends of the coronary bypassed vein grafts were anastomosed and coronary perfusion was established and maintained until this artery was anastomosed to the aortic graft. Then, the aneurysms in the distal arch and descending thoracic aorta were excised and the aorta and its two pairs of intercostal arteries were reconstructed. The Postoperative course was uneventful with favorable cardiac function.