Five-Year Outcomes of Successful Percutaneous Coronary Intervention with Drug-Eluting Stents versus Medical Therapy for Chronic Total Occlusions

PURPOSE: Many recent studies have reported that successful percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) for chronic total occlusion (CTO) has more beneficial effects than failed CTO-PCI; however, there are only limited data available from comparisons of successful CTO-PCI with medical therapy (MT) in the Korean population. MATERIALS AND METHODS: A total of 840 consecutive CTO patients who underwent diagnostic coronary angiography, receiving either PCI with DESs or MT, were enrolled. Patients were divided into two groups according to the treatment assigned. To adjust for potential confounders, propensity score matching (PSM) analysis was performed using logistic regression. Individual major clinical outcomes and major adverse cardiac events, a composite of total death, myocardial infarction (MI), stroke, and revascularization, were compared between the two groups up to 5 years. RESULTS: After PSM, two propensity-matched groups (265 pairs, n=530) were generated, and the baseline characteristics were balanced. Although the PCI group showed a higher incidence of target lesion and vessel revascularization on CTO, the incidence of MI tended to be lower [hazard ratio (HR): 0.339, 95% confidence interval (CI): 0.110 to 1.043, p=0.059] and the composite of total death or MI was lower (HR: 0.454, 95% CI: 0.224 to 0.919, p=0.028), compared with the MT group up to 5 years. CONCLUSION: In this study, successful CTO PCI with DESs was associated with a higher risk of repeat PCI for the target vessel, but showed a reduced incidence of death or MI.

Surgical Removal of a Left Ventricular Thrombus Which Showed Morphologic Changes Over Time in a Patient with Stress-Induced Cardiomyopathy

Although stress-induced cardiomyopathy (SCMP) is a reversible disease and the prognosis is usually excellent, several complications can occur and can result in fatal adverse events. The formation of left ventricular (LV) thrombus is one of these critical complications of SCMP. This report describes a case of SCMP complicated by formation of a LV thrombus that became increasingly mobile as LV contractility recovered, and for which surgical removal was performed. Here, we report a case of SCMP complicated by LV thrombus and review the literature regarding this topic.

Short- and Long-Term Results of Triple Valve Surgery: A Single Center Experience

Triple valve surgery is usually complex and carries a reported operative mortality of 13% and 10-yr survival of 61%. We examined surgical results based on our hospital's experience. A total of 160 consecutive patients underwent triple valve surgery from 1990 to 2006. The most common aortic and mitral valve disease was rheumatic disease (82%). The most common tricuspid valve disease was functional regurgitation (80%). Seventy-four percent of the patients were in New York Heart Association (NYHA) class III and IV. Univariate and multivariable analyses were performed to identify predictors of early and late survival. Operative mortality was 6.9% (n=11). Univariate factors associated with mortality included old age, preoperative renal failure, postoperative renal failure, pulmonary complications, and stroke. Of them, postoperative renal failure and stroke were associated with mortality on multivariable analysis. Otherwise, neither tricuspid valve replacement nor reoperation were statistically associated with late mortality. Survival at 5 and 10 yr was 87% and 84%, respectively. Ninety-two percent of the patients were in NYHA class I and II at their most recent follow-up. Ten-year freedom from prosthetic valve endocarditis was 97%; from anticoagulation-related hemorrhage, 82%; from thromboembolism, 89%; and from reoperation, 84%. Postoperative renal failure and stroke were significantly related with operative mortality. Triple valve surgery, regardless of reoperation and tricuspid valve replacement, results in acceptable long-term survival.

Small Aortic Annulus in Aortic Valve Replacement; Comparison between Aortic Annular Enlargement Group and Patient-prosthesis Mismatch Group / 대한흉부외과학회지

BACKGROUND: The effect of patient-prosthesis mismatch (PPM) on the clinical outcome following aortic valve replacement (AVR) remains controversial. This study compared the surgical outcomes of AVR between patients with a patient-prosthesis mismatch and those having undergone an aortic annular enlargement. MATERIAL AND METHOD: Six hundred and twenty seven adult patients, who underwent AVR with stented bioprosthetic or mechanical valves, between January 1996 and February 2006, were evaluated. PPM was defined as an indexed effective orifice area (iEOA) < or =0.85 cm2/m2, and severe if the iEOA < or =0.65 cm2/m2. PPM was present in 103 (16.4%, PPM group) patients, and severe in 11 (1.8%, SPPM group). During the period of the study, 21 patients underwent an AVR with annular enlargement (AE group). RESULT: The mean iEOA of the AE group was larger than that of the PPM group (0.95 vs. 0.76 cm2/m2, p=0.00). The AE group had longer CPB, ACC and operation times than the PPM group, and showed a tendency toward higher operative mortality (14.3% vs. 2.9%, p=0.06). The SPPM group had higher AV pressure gradients (peak/mean) than the AE group (72/45 mmHg vs. 38/25 mmHg, p=0.02/0.06) and suffered more AV related events (AV reoperation or severe aortic stenosis)(45.5% vs. 9.5%, p=0.03). LV masses were not regressed in the patients who experienced an AV related event. CONCLUSION: During AVR in patients with a small aortic annulus, annular enlargement should be carefully applied taking into account the high risk of operative mortality due to annular enlargement and co-morbidities of patients. Aortic annular enlargement; however, should be considered as an alternative method in patients expected to have a severe PPM after an AVR.

Surgical Treatment of Cardiac Myxoma: A 20 Years of Experiences / 대한흉부외과학회지

BACKGROUND: Myxoma makes up close to 50% of adult primary cardiac tumors, and this mainly occurs in the left atrium, and rarely in the right atrium or ventricle. The patients clinically present with symptoms of hemodynamic obstruction, embolization or constitutional changes. Diagnosis is currently established most appropriately with 2-D echocardiography. Surgical resection of myxoma is a safe and effective treatment. MATERIAL AND METHOD: We reviewed our clinical experience in the diagnosis and management of 57 cases of cardiac myxoma that were seen over a 20-year period from July 1984 to July 2004. RESULT: The mean age of the patients was 53.5+/-14.0 years (range: 12 to 76 years). There were 38 (67%) females and 19 (33%) males. The preoperative symptoms included dyspnea on exertion in 27 patients, palpitation in 4, chest pain in 9 and syncopal episode in 4. The diagnosis was made by echocardiography alone in 51, and by combination of echocardiography, CT and angiography in 6. The tumor attachment sites were the interatrial septum in 50, the mital valve annulus in 3 and the left atrial wall in cases. The tumor was excised successfully via biatriotomy in 33 (58%), left atriotomy in 15 (26%), the septal approach via right atriotomy in 3, Inverted T incision in 3 and the extended septal approach in 3. The follow-up time ranged from 1 to 229 months (mean follow-up: 84.0+/-71.3 months). There were no early and late deaths and no recurrence during the follow-up period except for follow-up loss in 5 patients. CONCLUSION: It's concluded that excision of cardiac myxoma is curative and the long-term survival is excellent. Immediate surgical treatment was indicated because of the high risk of embolization or of sudden cardiac death. Radical tumor excision may prevent recurrences.

A case of acute myocardial infarction caused by a septic coronary embolism and treated with embolectomy / 대한내과학회지

An acute myocardial infarction caused by a septic coronary embolism is a known complication of infective endocarditis and usually carries a fatal prognosis. We experienced a case of a 27-year-old man with an acute myocardial infarction caused by a coronary embolism due to bacterial endocarditis. An echocardiogram demonstrated mitral valve regurgitation with highly mobile multiple vegetations. Because of the high risk of systemic embolization and congestive heart failure, the patient underwent emergency surgery. Mitral valve replacement and an embolectomy were performed successfully without any surgical complications.

Risk Factor Analysis for Spinal Cord and Brain Damage after Surgery of Descending Thoracic and Thoracoabdominal Aorta / 대한흉부외과학회지

BACKGROUND: Surgery of descending thoracic or thoracoabdominal aorta has the potential risk of causing neurological injury including spinal cord damage. This study was designed to find out the risk factors leading to spinal cord and brain damage after surgery of descending thoracic and thoracoabdominal aorta. MATERIAL AND METHOD: Between October 1995 and July 2005, thirty three patients with descending thoracic or thoracoabdominal aortic disease underwent resection and graft replacement of the involved aortic segments. We reviewed these patients retrospectively. There were 23 descending thoracic aortic diseases and 10 thoracoabdominal aortic diseases. As an etiology, there were 23 aortic dissections and 10 aortic aneurysms. Preoperative and perioperative variables were analyzed univariately and multivariately to identify risk factors of neurological injury. RESULT: Paraplegia occurred in 2 (6.1%) patients and permanent in one. There were 7 brain damages (21%), among them, 4 were permanent damages. As risk factors of spinal cord damage, Crawford type II.III (p=0.011) and intercostal artery anastomosis (p=0.040) were statistically significant. Cardiopulmonary bypass time more than 200 minutes (p=0.023), left atrial vent catheter insertion (p=0.005) were statistically significant as risk factors of brain damage. Left heart partial bypass (LHPB) was statistically significant as a protecting factor of brain (p=0.032). CONCLUSION: The incidence of brain damage was higher than that of spinal cord damage after surgery of descending thoracic and thoracoabdominal aorta. There was no brain damage in LHPB group. LHPB was advantageous in protecting brain from postoperative brain injury. Adjunctive procedures to protect spinal cord is needed and vigilant attention should be paid in patients with Crawford type II.III and patients who have patent intercostal arteries.

Risk Factor Analysis for Operative Death and Brain Injury after Surgery of Stanford Type A Aortic Dissection / 대한흉부외과학회지

BACKGROUND: Surgery for Stanford type A aortic dissection shows a high operative mortality rate and frequent postoperative brain injury. This study was designed to find out the risk factors leading to operative mortality and brain injury after surgical repair in patients with type A aortic dissection. MATERIAL AND METHOD: One hundred and eleven patients with type A aortic dissection who underwent surgical repair between February, 1995 and January, 2005 were reviewed retrospectively. There were 99 acute dissections and 12 chronic dissections. Univariate and multivariate analysis were performed to identify risk factors of operative mortality and brain injury. RESULT: Hospital mortality occurred in 6 patients (5.4%). Permanent neurologic deficit occurred in 8 patients (7.2%) and transient neurologic deficit in 4 (3.6%). Overall 1, 5, 7 year survival rate was 94.4, 86.3, and 81.5%, respectively. Univariate analysis revealed 4 risk factors to be statistically significant as predictors of mortality: previous chronic type III dissection, emergency operation, intimal tear in aortic arch, and deep hypothemic circulatory arrest (DHCA) for more than 45 minutes. Multivariate analysis revealed previous chronic type III aortic dissection (odds ratio (OR) 52.2), and DHCA for more than 45 minutes (OR 12.6) as risk factors of operative mortality. Pathological obesity (OR 12.9) and total arch replacement (OR 8.5) were statistically significant risk factors of brain injury in multivariate analysis. CONCLUSION: The result of surgical repair for Stanford type A aortic dissection was good when we took into account the mortality rate, the incidence of neurologic injury, and the long-term survival rate. Surgery of type A aortic dissection in patients with a history of chronic type III dissection may increase the risk of operative mortality. Special care should be taken and efforts to reduce the hypothermic circulatory arrest time should always be kept in mind. Surgeons who are planning to operate on patients with pathological obesity, or total arch replacement should be seriously consider for there is a higher risk of brain injury.

Outcomes of the Modified Maze Procedure for Chronic Atrial Fibrillation Combined with Rheumatic Mitral Valve Disease / 대한흉부외과학회지

BACKGROUNG: The aim of this study was to investigate the mid-term outcomes of our modifications to the maze procedure using cryoablation for treating atrial fibrillation associated with rheumatic mitral valve disease. MATERIAL AND METHOD: Between March 2000 and February 2004, 177 consecutive patients underwent the modified maze procedure with the use of cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, and were divided into three groups: (1) modified Cox-maze III (CM group, n=88); (2) modified Kosakai-maze (KM group, n=63); and (3) left atrial maze procedure (LA group, n=26). The postoperative and follow- up results were analyzed and compared between the groups. RESULT: There were three hospital deaths (1.7%) and no significant differences in the incidence of postoperative complications between the three groups. The operative time, such as the cardiopulmonary bypass and aortic crossclamp time, were significantly longer in the CM group than in the KM and LA groups, respectively (p<0.0001). The mean follow-up was 22.4+/-15.1 months (1~52.6 months) for all patients. One late death developed in the CM group (0.6%). At last follow-up, 139 patients exhibited sinus rhythm (79.9%), which was also regained in 67 patients (77.9%) in the CM group, 50 (80.7%) in the KM group and 22 (84.6%) in the LA group (p=0.743). The actuarial freedom from stroke at 4 years was 84.6+/-9.4% in the CM group, 95.0+/-4.9% in the KM group, and 92.9+/-6.9% in the LA group (p=0.916). CONCLUSION: The modified maze procedure using cryoablation is safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.

Assessment of the Quality of Esophago-gastric Anastomosis by Endoscopic Examination Cervical Versus Intrathoracic Anastomosis / 대한흉부외과학회지

BACKGROUND: Mortality and morbidity of anastomotic complications after esophagectomy have gradually decreased in recent years. However, swallowing difficulties and reflux symptoms after esophagogastrostomy continue to be a burden jeopardizing the quality of life. In the present study, we evaluated the quality of esophagogastrostomy by analyzing anastomotic stenosis and reflux esophagitis. MATERIAL AND METHOD: A retrospective analysis was made in 74 patients who underwent esophagogastrostomy after esophagectomy by one surgeon between January 1995 and December 2004. 53 patients of them received endoscopic examination during follow-up (29+/-23.6 months, range 5~111 months). Reflux esophagitis and stenosis at anastomostic site were analyzed according to the techniques and locations of esophagogastrostomy. RESULT: The median age at the time of repair was 60.3+/-8.87 years (range 39~81 years). 23 patients received a hand-sewn esophagogastric anastomosis and 30 patients a circular stapled one. There was no significant statistical difference in terms of anastomotic stenosis (p=0.64) and reflux esophagitis (p=0.41) between the two groups. Cervical anastomosis was performed in 26 patients and intrathoracic anastomosis in 27 patients. No significant statistical difference in anastomotic stenosis between the two groups was found (p=0.44), but reflux esophagitis was noted in 3 patients in the cervical anastomosis group and 14 patients in the intrathoracic anastomosis group (p=0.003). CONCLUSION: Cervical anastomosis was supposed to have a better quality of esophagogastrostomy by lowering the risk of reflux esophagitis. In the future, the comprehensive study including a patient's subjective symptom and Barrett's metaplasia should be performed in larger cases.

Right Ventricular Perforation and Left Hemothorax by Permanent Transveneous Pacemaker Lead: Report of 1 Case / 대한흉부외과학회지

Bleeding due to cardiac perforation by endocardial pacemaker lead is a rare complication. We report one case of left hemothorax due to right ventricular perforation after the insertion of permanent transvenous pacemaker. Operative finding showed a pacing lead penetrating right ventricle, pericardium, and left pleura sequentially, but there was no evidence of hemopericardium.

Aortic Valve Papillary Fibroelastoma: Report of 1 Case / 대한흉부외과학회지

Papillary fibroelastomas are benign, and they are the second most common primary cardiac tumors usually involving the cardiac valve. Papillary fibroelastoma attached to the free margin of right coronary cusp of the aortic vlave was found incidentally during the work-up of a 51-year-old woman, who was presented with palpitation and dyspnea. During the operation, the tumor mass was excised without leaving defect on the aortic valve leaflet.

Homograft Aortic Root Replacement / 대한흉부외과학회지

BACKGROUND: Homograft aortic valve replacement (AVR) has many advantages such as excellent hemodynamic performance, faster left ventricular hypertrophy regression, resistance to infection and excellent freedom of thromboembolism. To find out the results of homograft AVR, we reviewed our surgical experiences. MATERIAL AND METHOD: Eighteen patients (male:female=16:2, mean age=39.3+/-16.2 years, range: 14~68 years) who underwent homograft aortic valve replacement between May 1995 and May 2004 were reviewed. The number of homografts was 20 (17 aortic and 3 pulmonic homografts) including two re-operations. Ten patients had a history of previous aortic valve surgery. Indications for the use of a homograft were native valve endocarditis (n=7), prosthetic valve endocarditis (n=5), or Behcet's disease (n=8). The homograft had been implanted predominantly as a full root except in one patient in the subcoronary position. RESULT: Mean follow-up was 41.3+/-26.2 months. There was one operative mortality. Postoperative complications included postoperative bleeding in 3 patients, and wound infection in 1. There was no late death. Three patients underwent redo-AVR. The etiology of the three reoperated patients was Behcet's disease (p=0.025). Freedom from reoperation was 87.5+/-8.3%, 78.8+/-11.2% at 1, 5 years respectively. In patients with infective endocarditis, there was no recurrence of endocarditis. There was no thromboembolic complication. CONCLUSION: Although longer term follow-up with larger numbers of patients is necessary, the operative and mid-term results for homograft AVR was good when we took into account the operative risks of Behcet's disease or infective endocarditis. Behcet's disease was a risk factor for reoperation after the homograft AVR. We think homograft AVR is the procedure of choice, particularly in patients with infective endocarditis.

Reduction Aortoplasty with Suture Plication Technique for Dilatation of the Ascending Aorta associated with Aortic Valve Disease / 대한흉부외과학회지

BACKGROUND: Reduction aortoplasty has been advocated for dilatation of the ascending aorta associated with aortic valve disease in older, high-risk patients. We report our results with modification of reduction aortoplasty and aortic valve replacement. MATERIAL AND METHOD: Between July 2001 and December 2002, 14 consecutive patients who underwent modification of reduction aortoplasty, suture plication technique without excision of the dilated aortic wall, were reviewed. The mean age was 63.7+/-6.7 (50 to 75) years. Ten patients had congenital bicuspid aortic valve. Twelve patients had severe aortic valve stenosis and 6 had regurgitation of grade III~IV. The diameter of the ascending aorta was measured before and immediately after surgery and 6 and 12 months postoperatively using echocardiography or computed tomography. Follow-up was complete in an average of 14.7+/-5.4 (7 to 24) months. RESULT: There were no early postoperative deaths and no bleeding complications. Reduction aortoplasty with suture plication technique decreased the diameter of ascending aorta from 49.4+/-3.5 mm preoperatively to 33.2+/-3.4 mm postoperatively (p<0.001). During follow-up, there were no late deaths and no aneurysm recurrence on the ascending aorta. CONCLUSION: Suture plication technique of reduction aortoplasty without excision of the dilated aortic wall offers good early and short-term results in older, high-risk patients with dilatation of the ascending aorta associated with aortic valve disease. Surgical long-term results of our technique should be evaluated in further studies.

The Recovery of Left Ventricular Function after Coronary Artery Bypass Grafting in Patients with Severe Ischemic Left Ventricular Dysfunction: Off-pump Versus On-pump / 대한흉부외과학회지

BACKGROUND: Adverse effects of cardiopulmonary bypass can be avoided by "Off-pump" coronary artery bypass (OPCAB) surgery. Recent studies have reported that OPCAB had the most beneficial impact on patients at highest risk by reducing bypass-related complications. The purpose of this study is to compare the outcome of OPCAB and conventional coronary artery bypass grafting (CCAB) in patients with poor left ventricular (LV) function. MATERIAL AND METHOD: From March 1997 to February 2004, seventy five patients with left ventricular ejection fraction (LVEF) of 35% or less underwent isolated coronary artery bypass grafting at our institute. Of these patients, 33 patients underwent OPCAB and 42 underwent CCAB. Preoperative risk factors, operative and postoperative outcomes, including LV functional change, were compared and analysed. RESULT: Patients undergoing CCAB were more likely to have unstable angina, three vessel disease and acute myocardial infarction among the preoperative factors. OPCAB group had significantly lower mean operation time, less numbers of total distal anastomoses per patient and less numbers of distal anastomoses per patient in the circumflex territory than the CCAB group. There was no difference between the groups in regard to in-hospital mortality (OPCAB 9.1% (n=3) Vs. CCAB 9.5% (n=4)), intubation time, the length of stay in intensive care unit and in hospital postoperatively. Postoperative complication occurred more in CCAB group but did not show statistical difference. On follow-up echocardiography, OPCAB group showed 9.1% improvement in mean LVEF, 4.3 mm decrease in mean left ventricular end-diastolic dimension (LVEDD) and 4.2 mm decrease in mean left ventricular end-systolic dimension (LVESD). CCAB group showed 11.0% improvement in mean LVEF, 5.1 mm decrease in mean LVEDD and 5.5 mm decrease in mean LVESD. But there was no statistically significant difference between the two groups. CONCLUSION: This study showed that LV function improves postoperatively in patients with severe ischemic LV dysfunction, but failed to show any difference in the degree of improvement between OPCAB and CCAB. In terms of operative mortality rate and LV functional recovery, the results of OPCAB were as good as those of CCAB in patients with poor LV function. But, OPCAB procedure was advantageous in shortening of operative time and in decrease of complications. We recommend OPCAB as the first surgical option for patients with severe LV dysfunction.

Congenital Quadricuspid Aortic Valve / 대한흉부외과학회지

Quadricuspid aortic valve is a rare congenital abnormality but it is well recognized as the cause of significant aortic regurgitation. We describe 5 patients who underwent surgery for severe aortic regurgitation associated with quadricuspid valve. In all patients, this abnormality had been incidentally detected during surgery. Two of the patients had infective endocarditis. In accordance with the Hurwitz and Roberts classification, two valves were type d, two were type a, and one was type c.

The Results of Extracardiac Fontan Operation in the Patients with Heterotaxy Syndrome / 대한흉부외과학회지

BACKGROUND: Historically the Fontan operation in patients with single ventricle and heterotaxy syndrome has been associated with high mortality because of systemic or pulmonary anomalous venous drainage, incompetent common atrioventricular valve, right ventricle type univentricular heart, and arrhythmia. MATERIAL AND METHOD: A retrospective review of 62 patients (age: 54.79+/-33.97 months) with heterotaxy syndrome who underwent a extracardiac Fontan operation between 1996 and 2005 was performed. Twenty one patients had left atrial isomerism, and 41 had right isomerism. The Fontan procedure was staged in all but 2 patients, and a fenestration was less placed in left isomerism. RESULT: Left isomerism was associated more with interrupted inferior vena cava and pulmonary arteriovenous fistula, and right isomerism was associated more with anomalous pulmonary venous drainage, common atrioventricular valve and morphologic right ventricle. There were 3 hospital deaths (4.8%), and 3 late deaths (5.2%) with a follow-up duration of 48.8+/-31.0 months. Eight-year survivals were 90.5+/-6.4% in left isomerism and 88.6+/-5.4% in right isomerism (p=0.94). At 8 years, freedom from reoperation was 73.9+/-11.3% in left isomerism, and 82.3+/-6.7% in right isomerism (p=0.87). Atrioventricular valve regurgitation progressed after Fontan operation in heterotaxy syndrome, and reoperation for pulmonary arteriovenous fistula and permanent pacemaker implantation for sinus node dysfunction were required more in left isomerism. CONCLUSION: The extracardiac Fontan operation can now be performed in patients with heterotaxy syndrome with excellent survival. However, morbidity in terms of postoperative atrioventricular valve regurgitation, arrhythmia, and pulmonary arteriovenous fistula remains significant.

Acute Myocardial Infarction after Embolic Occlusion of Left Anterior Descending Artery by Prosthetic Valve Thrombosis: Report of 1 case / 대한흉부외과학회지

Acute myocardial infarction due to coronary occlusion by emboli originating from the prosthetic valve thrombosis is very rare but fatal disease which needs immediate diagnosis and urgent treatment. We report a case of acute myocardial infarction after left anterior descending embolic occlusion in whom had previous mitral valve replacement. Redo valve replacement following the interventional catheterization and antiplatelet therapy lead to successful results.

Leaflet Escape of Edwards Duromedics Mechanical Heart Valve: Report of 1 case / 대한흉부외과학회지

Edwards Duromedics Valve has been suspended from the market since May 1988 due to the frequent reports of leaflet escape. There were 2 case-reports of leaflet escapes in this country. We report a case of leaflet escape in an Edwards Duromedics bileaflet valve, in the mitral position.

Significance of Microembolic Signals during Oxygen Inhalation in Patients with Prosthetic Mechanical Heart Valve / 대한흉부외과학회지

BACKGROUND: Transcranial Doppler ultrasonography (TCD) can detect microembolic signals (MES) in the patients with a potential embolic source. Clinical significance of MES has not been demonstrated in patients with prosthetic mechanical heart valves. We studied the correlation between cerebral thromboemoblic events after the mechanical heart valve surgery (MHVS) and residual MES during TCD monitoring with 100% oxygen inhalation in patients with mechanical heart valves. MATERIAL AND METHOD: Twenty patients with previous cerebral thromboemoblic events after MHVS and a sex- and age-matched control group (n=30) were studied. TCD monitoring was performed from unilateral middle cerebral artery. After baseline monitoring for 20 minutes, 6L of oxygen was inspired for 40 minutes. RESULT: The site of valve and the duration after MHVS of the patients did not differ from those of controls. During baseline monitoring, there was no significant difference in MES prevalence or counts compared to controls. During oxygen inhalation, patients showed a higher MES prevalence (55%, 27.6%, p=0.045) and a more frequent MES counts (p=0.027) compared to controls. CONCLUSION: TCD monitoring with oxygen inhalation may be useful to differentiate clinically significant MES in patients with mechanical heart valve.