CONTRAST ECHOES DETECTED DURING PERCUTANEOUS MITRAL BALLOON COMMISSUROTOMY WITH INOUE BALLOONS AND THEIR RELATION TO CEREBRAL MICROEMBOLIC SIGNALS

The aim of this study was to find out the mechanism of genesis of cont rast echoes detected with echocardiography during percutaneous mitral balloon commissurotomy (PMBC) procedures with Inoue balloons and to as sess their association with cerebral microembolic signals with transcr anial Doppler examinations. Ten Inoue balloons (Toray Instruments) wer e used in 10 patients (mean age 36 +/- 10 years). In all patients tran sesophageal echocardiographies with a multiplane 5 MHz probe were perf ormed immediately before and during the PMBC procedure. None of the pa tients had left atrial thrombus during the PMBC. All of the balloons w ere inflated within the left atriums and left ventricles and were test ed in saline to see whether there was a visible air leak after the PMB C procedures. Transcranial Doppler examinations were done with 2 MHz p robes from the middle cerebral artery. Contrast echoes were detected i n all patients during inflation and/or deflation, independent of the i ntracardiac sites. After a few cardiac cycles there was a very intense shower of microembolic signals detected with the transcranial Doppler examination, which persisted for all inflations and/or deflations. Al l balloons yielded visible air leaks from the two small holes at the w aist of the balloons in saline. There were a few contrast echoes recor ded in some of the patients during the exchange of equipment, and one patient had a transient neurologic and coronary ischemic event followi ng the introduction of the stretcher tube of the Inoue balloon. Intrac ardiac contrast echoes and transcranial microembolic signals during th e PMBC procedure were detected in all PMBC procedures and were due to air that was entrapped between the two latex layers of the Inoue ballo ons and air introduced from outside during the exchange of the, equipm ent.