田中 稔¹, 阿部 稔雄¹, 日比 範夫²

Minoru TANAKA¹, Toshio ABE¹, Norio HIBI²

¹名古屋大学医学部胸部外科, ²掛川市立総合病院内科

¹Department of Thoracic Surgery, Nagoya University, School of Medicine, ²Department of Internal Medicine, Kakegawa Municipal Hospital

キーワード : Intraoperative echocardiography, Valvular function, Open heart surgery

Valvular function was evaluated by intraoperative M–mode, two–dimensional, pulsed Doppler and real–time two–dimensional Doppler echocardiography in 107 patients, of whom 97 had aquired valvular disease and 7 had Stanford type A aortic dissection. Intraoperative echocardiography (IOE) was performed by placing a transducer sterilized by ethelene oxide gas directly on the surface of the heart or great vessels before cannulation for cardiopulmonary bypass (CPB) and after discontinuance of CPB. In addition to a commercially available transducer, we have developed a new one for intraoperative use. In 18 patients (16.8%), emergency surgery was performed without preoperative angiography or cardiac catheterization. Intraoperative echocardiography allowed us to make a precise diagnosis and to perform the correct surgical procedure for all 18 patients, whose diagnoses were infective endocarditis in 6, prosthetic valve dysfunction in 4, severe valvular disease in 6 and aortic dissection in 2. In 87 patients, 115 diseased valves were replaced with prosthetic valves, the function of which was also evaluated intraoperatively. In 2 patients who suffered hemodynamic deterioration upon discontinuance of CPB following mitral valve replacement, intraoperative echocardiography revealed prosthetic valve dysfunction, making it possible to repair the dysfunction. Both of them survived the catastrophic event due largely to a rapid and accurate diagnosis. In 44 patients who underwent valvular repair–aortic valve resuspension for aortic regurgitation secondary to aortic dissection in 5, mitral valve repair in 14 and tricuspid valve repair in 25–the presence and severity of residual regurgitation and stenosis was assessed after CPB. One patient was found to have significant tricuspid regurgitation and successfully underwent tricuspid valve replacement before chest closure. The usefulness of this method was also confirmed in 4 patients who needed emergency surgery for prosthetic valve dysfunction. In a patient who survived strut fracture of a Björk–Shiley mitral valve, IOE aided in detecting and retrieving the dislodged disc. In another patient who suffered thrombosed valve seven years after aortic and mitral valve replacement with Björk–Shiley valves, it was an important intraoperative method for determining which valve was thrombosed.
In conclusion, IOE has the potential for reducing the morbidity and mortality associated with surgery for valvular disease and aortic dissection by allowing the surgeons to obtain additional information that helps them in decision making with regard to appropriate surgical management, and to assess the result of the operation before chest closure.