Clinical Experiences of MIDCAB - Developmental Stage and Early Short-term Results / 대한흉부외과학회지

BACKGROUND: Minimally invasive direct coronary artery bypass surgery(MIDCAB) has been increasing in interest along with the new techniques in myocardial immobilization for easier and safer procedures. Until the opening of the era of new techniques, adequate accuracy and good patency of grafts were debatable. Our experiences of MIDCAB were studied according to the stages of technical developments. Material and Methods: Since March 1996, 55 patients have undergone MIDCAB procedures. The patients of off-pump CABG(no cardiopulmonary bypass under full sternotomy) were excluded from the study. In the early experience(Stage I), a left anterior small thoracotomy through the left parasternal incision was performed(n=6); then an approach through the lower partial sternotomy was used(Stage II, n=33); and recently, a chest wall elevator for harvesting the internal thoracic artery and the foot plate for myocardial immobilization have been used(USSC, Norwalk, CT)(Stage III, n=16). RESULT: The surgical procedures of four patients in the Stage II group have been converted to conventional bypass because of the deeply seated left anterior descending coronary artery in two patients, fracture of the calcific lesion in the right coronary artery in one patient, and a cardiogenic shock during hypothermia in the other patient with ventricular dysfunction. Two patients in stage II experienced symptomatic recurrences after surgery and restenosis was verified on angiocardiography. They were managed by interventional procedures. All the other patients were doing well without symptoms, except one patients in Stage II who underwent PTCA procedure for a lesion in the circumflex artery during the follow up period. CONCLUSION: The new and specialized devices are essential to the development of MIDCAB surgery. MIDCAB and the hybrid procedures in multi-vessel disease are on the way to further development. So far, our experience is limited only to a single device among the many new devices for the purpose.

Repair of Complete Atrioventricular Septal Defect with Surgical Modification / 대한흉부외과학회지

BACKGROUND: Recent advances in understanding the anatomy of the complete atrioventricular septal defect(including right-dominant unbalanced atrioventricular septal defect) have led to alternative methods of repairing these defects. MATERIAL AND METHOD: From May 1997 to July 1998, 8 consecutive infants(age range, 2 to 28 months, mean body weight 6.0+/-2.2 kg) received a single-stage intracardiac repair of the complete atrioventricular septal defect with modified surgical methods. Depending on the specific anatomic structure, the procedure was simplified in 3 patients by a direct closure of the ventricular element of the defect(Group I). Two patients judged unsuitable for direct closure due to a potential left ventricular outflow tract obstruction had received a standard two-patch repair(Group II). The remaining 3 patients with right-dominant unbalanced complete atrioventricular septal defect underwent biventricular repair; to enlarge the orifice of the left atrioventricular valve, the ventricular septal patch was placed slightly more to the right of the ventricular crest, a left sided bridging leaflet was augmented with an autologous pericardial patch, and the leaflet was repaired with a double- orifice(Group III . RESULT: In all 8 patients, the postoperative echocardiography demonstrated good hemodynamics. Seven patients were weaned from the ventilators after a mean 3+/-1 days, and 1 patient was weaned after 24 days due to a reoperation and emphysematous lung problem. A reoperation was performed in 1 patient for progressive left atrioventricular valve regurgitation due to leaflet tearing. There were no early and late mortalities. At the time of the latest review, judging from the echocardiographic criteria, left atrioventricular valve stenosis was mild in 1 patient(mean pressure gradient 6.5 mmHg, 13.5%), left atrioventricular valve regurgitation was absent or grade I in 7 patients(87.5%). The right atrioventricular valve regurgitation was absent or grade I in all 8 patients(100%). CONCLUSION: Infants with complete atrioventricular septal defect were treated with either a simplified approach with direct closure of the ventricular element of the defect or a modified surgical technique for a right-dominant unbalanced atrioventricular septal defect, depending on the anatomic structure. The results were no operative mortalities and low morbidity.

Early result of Coronary Artery Bypass Grafting Using the Internal Thoracic and the Radial Arteries / 대한흉부외과학회지

BACKGROUND: Increasing interest in the use of arterial conduites is based on the better patency of the internal thoracic artery(ITA) than the saphenous vein graft and the hope that other arterial conuits will perform similarly over the long term. MATERIAL AND METHOD: Between May 1997 and July 1998, 43 patients underwent coronary artery bypass grafting with ITA and the radial artery(RA). There were 28 men and 15 women with a mean age of 61.5 years(range, 35 to 78). In 43 patents, 30 bilateral ITA(including 7 diabetes mellitus, 5 more older 70 years), 8 bilateral ITA only, 2 left ITA and both RA, 11 left ITA and left RA and 22 both ITA and left RA were used. RESULT: There was 1 hospital mortality. Of the 42 patients alive, 39 patients are asymptomatic. Postoperative complications were postoperative bleeding in 1 patients, and low cardiac output syndrome in 3. Follow-up angiography was performed in 5 patients after the operation(mean 3 months), and all ITA & RA grafts showed excellent results. CONCLUSION: We conclude that complete arterial revascularization with internal thoracic artery and radial artery is technically feasiale with low mortality and morbidity, and but long term follow-up is needed.

Reconstruction of Injured or Inadquate Left Internal Thoracic Artery in Cornonary Artery bypass Graft / 대한흉부외과학회지

BACKGROUND: Use of the left internal thoracic artery(ITA) to bypass the left anterior descending(LAD) coronary artery has become the standard of care based on its superior graft patency, reduced cardiac events, and enhanced survival. But rarely we encountered with injury to the artery during harvesting which leads to loss of the merits of surgery. We reconstructed inadequate ITAa with other arterial conduits so proximal stump to be a blood source if possible. MATERIAL AND METHOD: Between January 1996 and March 1999, 12 patients received bypass with the reconstructed left internal thoracic artery grafts to left anterior descending artery because of an injury(n=8), short or small(n=4). Right or left ITA was used to LAD as a free graft(n=2). And the other 10 left ITAs were extended with radial artery(n=6), right ITA(n=3), saphenous vein(n=1). Composite "T" graft was made with other arterial conduits in these extended graft(n=5). RESULT: There was only one morbidity of minor would problem, and no mortality. The patency of extended graft to LAD was complete in 5 patients who received angiography during the period of 2wks to 2 years postoperative, but one of side branch of "T" graft occluded. All of these patients were well. CONCLUSION: Reconstructive extension with the use of other arterial conduit for the injured proximal ITA is warranted in any patients with acceptable results.

Pulmonary Autograft Replacement in Native Aortic Root Abscess / 대한흉부외과학회지

Bacterial endocarditis of the native aortic valve is associated with significant morbidity and mortality despite aggressive medical and surgical treatment, especially when perivalvular tissue was invaded and destructed. The pulmonary autograft is full viable and immune compatible tissue. This paper describes successful Ross operation as total root replacement in 38 years old native valve endocarditis patient with aortic root abscess.

Minimally Invasive Coronary Artery Bypass Grafting / 대한흉부외과학회지

Minimally invasive coronary artery bypass grafting without using cardiopulmonary bypass (CPB) is a recently accepted modality of myocardial revascularization prcedures which is particularly suitable to the patients with lesions in the left anterior descending (LAD) and the right coronary arteries. Of the consecutive 35 patients of coronary artery bypass grafting performed at Sejong General Hospital from March to August 1996, six patients underwent minimally invasive coronary artery bypass grafting without CPB. All had stenotic lesions of the LAD more than 90%. Bypass grafting of the LAD was approached through midline sternotomy in one, through ministernotomy in two, and through limited left anterior thoracotomy in three patients, respectively. The internal mammary arteries were prepared without the use of thoracoscope. The mobilized mammary arteries were connected directly to the LAD in 5 patients, and the anastomosis required interposition of a segment of the radial artery in the remaining one. The diagonal branch was revascularized with the saphenous vein graft at the same time in one patient. No blood transfusion was necessary in 2 patients, and average blood required during surgery was 800ml in 4 patients. All patients were extubated from 4 to 14 hours (mean 9 hours) after operation. Early postoperative coronary angiography in 5 patients between 7 and 10 days after surgery has proved full patency of the grafts. With these limited clinical experiences, the clinical results demonstrated that minimally invasive coronary artery bypass grafting without CPB is an useful procedure especially in patients with isolated lesion in the proximal LAD.

Use of the Native Aortic Valve as the Pulmonary Valve in the Ross Procedure / 대한흉부외과학회지

Aortic valve replacement in young patients has its problems. Biologic prosthetic valves degenerate and need replacement. Metalic prosthetic valves are more durable, however, anticoagulation which has its inherent problems is inevitable. The use of Ross procedure in young patients is gaining wider acceptance. The need of foreign pulmonary valve in right ventricular outflow tract (RVOT) will require reoperation due to RVOT obstruction, later. To overcome this problem, we reimplanted the native aortic valve in the pulmonary position in 21 year old female patient operated on utilizing the Ross procedure for aortic insufficiency. We experienced that the diseased aortic valve worked well in the pulmoanry position because of low pulmonary artery pressure and resistance.

Early Results of Extracardiac Fontan Operation / 대한흉부외과학회지

Between August 1996 and August 1997, 22 patients underwent extracardiac Fontan operations. The basic diagnoses included univentricular heart of the right ventricular type (n=12); univentricular heart of the left ventricular type (n=4); tricuspid atresia (n=4); left isomerism, transposition of great arteries, ventricular septal defect and pulmonary stenosis (n=1); and criss-cross heart with uneven ventricle (n=1). The median age of the 14 men and 8 women was 29 months (range from 21 months to 26 years). Previous procedures included bidirectional cavopulmonary shunt (n=15, interval=15.6+/-3.4 months), Kawashima operation (n=4, interval=37.5+/-20 months), and classic Glenn shunt (n=1, interval=14 years). In 2 patients, extracardiac Fontan operations were done without any previous procedures. A 16-to 22-mm flexible Gore-Tex tube graft (n=18), Hemashield graft (n=3), or, alternatively, a nonvalved aortic allograft (n=1) was cut and anastomosed end-to-end between inferior vena cava and undersurface of pulmonary artery using Gore-Tex or Prolene suture in a running fashion. In risk Fontan patients (n=12), a communication between the extracardiac conduit and the right atrium was constructed. In the most 13 recent patients, the procedures were done without cross-clamping of the aorta and with a beating heart. Operative mortality was 9.1% (n=2). Complications included persistent chest tube drainage for more than 7 days (n=5), chorea (n=2), and low cardiac output (n=1). There were no late deaths. Follow-up echocardiogram (mean: 6 months) demonstrated satisfactory hemodynamic results in the surviving 20 patients. Potential advantages of this technique consist of minimization of surgical manipulation of atrial tissue, reduction or elimination of myocardial ischemia, creationof a uniform and stable inferior vena cava-to-pulmonary artery conduit, and increased flexibility and safety in certain high-risk patients such as those with increased pulmonary vascular resistance, pulmonary hypertension, and impaired ventricular function. Further investigations during a longer follow-up are needed to confirm the intermediate and long-term results, especially the reduction of late atrial arrhythmias.

Simplified Approach to Repair of Complete Atrioventricular Septal Defect / 대한흉부외과학회지

Recent advances in understanding the anatomy of complete atrioventricular septal defect have led to alternative methods of repairing these defects. Here we report two cases of complete atrioventricular septal defect repair by direct closure of the ventricular element of the defect. Follow-up for average of 3 months suggests that, when direct closure can be performed, the results can be comparable with those of the standard technique. Our initial success with this approach is encouraging; however, longer follow-up and more experiences are required to establish whether it will be broadly applicable.

Early Results of Coronary Bypass Surgery in Patients with Severe Left Ventricular Dysfunction / 대한흉부외과학회지

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60+/-5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class III in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4+/-4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 +/-8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5+/-1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 +/-13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.