Variations in Pulse Oximetry Plethysmographic Waveform Amplitude and Hemodynamic Assessment Induced by Passive Leg Raising in Spontaneously Breathing Adult Volunteers / 대한구급학회지

BACKGROUND: In hemodynamically unstable patients with spontaneous breathing activity, predicting volume responsivenss is a difficult challenge. Our objective was to test whether the respiratory changes in pulse oxymetry plethysmographic waveform amplitude (POP) and in stroke volume (deltaSV) could predict fluid responsiveness to passive leg raising (PLR) in normal volunteers. METHODS: We investigated 25 normal volunteers. We assessed hemodynamic status (HR, SBP, MAP, CI and SVI) and calculated the respiratory variation in pulse oximetry plethysmographic waveform amplitude at supine and after PLR. We attached a pulse oximeter of 25 spontaneously breathing volunteers as several time points: after 1 min and 5 min in supine position and during PLR at 60degrees. Heart rate, non-invasive blood pressures (mean arterial pressure, systolic blood pressure), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP defined as (POPmax-POPmin)/[(POPmax+POPmin)/2] were recorded using monitor. RESULTS: Comparing to supine and PLR, systolic blood pressure and mean arterial pressure were not different, but the change in cardiac index, stroke volume and respiratory variation in POP were significant different. In response group (> or =10% in deltaCI), the change in cardiac index, stroke volume and respiratory variation in POP were significant greater. CONCLUSION: PLR induces a significant decrement of variation in POP amplitude among spontaneouely breathing volunteers. We suppose that the changes in stroke volume and the respiratory variation in pulse oximetry plethysmographic waveform amplitude induced by PLR predict fluid responsiveness in spontaneous breathing patients.

Da Vinci Robot-Assisted Pulmonary Lobectomy in Early Stage Lung Cancer: 3 cases report / 대한흉부외과학회지

Video-assisted pulmonary lobectomy was introduced in the early 1990's by several authors, and the frequency of video-assisted thoracic surgery (VATS) lobectomy for lung cancer has been slowly increasing because of its safety and oncologic acceptability in patients with early stage lung cancer. However, VATS is limited by 2D imaging, an unsteady camera platform, and limited maneuverability of its instruments. The da Vinci Surgical System was recently introduced to overcome these limitations. It has a 3D endoscopic system with high resolution and magnified binocular views and EndoWrist instruments. We report three cases of da Vinci robot system-assisted pulmonary lobectomy in patients with early stage lung cancer.

The Comparison Study of Early and Midterm Clinical Outcome of Off-Pump versus On-Pump Coronary Artery Bypass Grafting in Patients with Severe Left Ventricular Dysfunction (LVEF< or =35%) / 대한흉부외과학회지

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) has been proven to result in less morbidity. The patients who have left ventricular dysfunction may have benefits by avoiding the adverse effects of the cardiopulmonary bypass. The present study compared early and midterm outcomes of off-pump versus on-pump coronary artery bypass grafting (On pump CABG) in patients with severe left ventricular dysfunction. MATERIAL AND METHOD: Ninety hundred forth six patients underwent isolated coronary artery bypass grafting by one surgeon between January 2001 and Febrary 2005. Data were collected in 100 patients who had left ventricular ejection fraction (LVEF) less than 35% (68 OPCAB; 32 On pump CABG). Mean age of patients were 62.9+/-9.0 years in OPCAB group and 63.8+/-8.0 years in On pump CABG group. We compared the preoperative risk factors and evaluated early and midterm outcomes. RESULT: In OPCAB and On pump CABG group, mean number of used grafts per patient were 2.75+/-0.72, 2.78+/-0.55 and mean number of distal anastomoses were 3.00+/-0.79, 3.16+/-0.72 respectively. There was one perioperative death in OPCAB group (1.5%). The operation time, ventilation time, ICU stay time, CK-MB on the first postoperative day, and occurrence rate of complications were significantly low in OPCAB group. Mean follow-up time was 26.6+/-12.8 months (4~54 months). Mean LVEF of OPCAB and On pump CABG group improved significantly from 27.1+/-4.5% to 40.7+/-13.0% and 26.9+/-5.4% to 33.3+/-13.7%. The 4-year actuarial survival rate of OPCAB and On pump CABG group were 92.2%, 88.3% and the 4-year freedom rates from cardiac death were 97.7%, 96.4% respectively. There were no significant differences between two groups in 4 year freedom rate from cardiac event and angina. CONCLUSION: OPCAB improves myocardial function and favors early and mid-term outcomes in patients with severe left ventricular dysfunction compared to On pump CABG group. Therefore, OPCAB is a preferable operative strategy even in patients with severe left ventricular dysfunction.

Effects of Preoperative Continuous Use of Aspirin and Plavix in Off-pump Coronary Artery Bypass Surgery / 대한흉부외과학회지

BACKGROUND: The benefits of preoperative use of aspirin and plavix in coronary patients have been well documented. Due to their bleeding tendency, there have been many discussions about when to stop the antiplatelet agent before operation. We evaluated the effects of preoperative continuous use of aspirin and plavix in OPCAB patients. MATERIAL AND METHOD: 123 patients underwent OPCAB from March, 2004 to Feb., 2005. We divided them into two groups; those who had continuous administration of aspirin and plavix during the preoperative period (n= 45, 36.6%) and those who discontinued them at least one day before the operation (n=78, 63.4%). We then compared the platelet count, hemoglobin/hematocrit level, graft patency, postoperative bleeding and related complications, and operation time between the two groups. The patients were also divided into long-term users (> or =1 month) and short-term users (<1 month), with the aforementioned factors equally compared. RESULT: There was no statistical difference between the two groups regarding postoperative bleeding, related complications, graft patency, operation time and mortality. Continuous users showed significantly low platelet levels on immediate post operation (p=0.02), postoperative day (POD) #1 (p=0.002) and POD #2 (p=0.021), respectively. But there was no difference on POD #7. Long-term users showed statistically significant difference in pre- and postoperative platelet count, but none in postoperative bleeding and related complications. CONCLUSION: Continuous use of aspirin and plavix did not increase postoperative bleeding or related complications. Also graft patency and mortality had no statistical differences in continuous users. We think that there is no need to stop aspirin and plavix before OPCAB.

Spontaneous Recovery of Renal Function after Off-pump Coronary Artery Bypass Grafting in Chronic Renal Failure Patients / 대한흉부외과학회지

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) has shown better outcome in chronic renal failure (CRF) patients by avoiding the effects of cardiopulmonary bypass. We evaluated renal function after OPCAB in CRF patients. MATERIAL AND METHOD: 656 patients underwent OPCAB between January, 2001 and December, 2004. Data were collected in 26 CRF patients (Cr>1.7 mg/dL). Preoperative/postoperative creatinine (Cr) levels, creatinine clearance and postoperative data were evaluated. We divided the patients into group 1 (Cr or =3 mg/dL). RESULT: Three patients started dialysis after surgery. Preoperative mean creatinine level (4.19+/-3.4 mg/dL) was elevated to 4.36+/-2.7 mg/dL at the third postoperative day and decreased below preoperative level at the fifth postoperative day. In group 1 (mean Cr level=1.87+/-0.25 mg/dL), Cr level reached its peak level of 2.19+/-0.52 mg/dL at the fourth postoperative day (p=0.017), with subsequent decrease. Patients without pre- or postoperative dialysis (n=15) showed peak Cr elevation on postoperative day four (p=0.017) and subsequent decrease (p=0.01). Postoperative creatinine clearance showed reverse correlation with creatinine level. CONCLUSION: Creatinine level was elevated at third/fourth postoperative day, but decreased 5 days after surgery. Thus, if urgent dialysis is not indicated, postoperative renal replacement therapy in CRF patients may be better to be considered after four days observation.

The Clinical Outcomes of Off-Pump Coronary Artery Bypass Grafting in the Octogenarians / 대한흉부외과학회지

BACKGROUND: With the increasing age of the population, coronary artery bypass grafting in the elderly patients is becoming common. Off-pump coronary artery bypass grafting (OPCAB) has been proven to be less morbidity and to facilitate early recovery. The elderly patients may have benefits by avoiding the adverse effects of the cardiopulmonary bypass. The purpose of this study is to evaluate our results of OPCAB in elderly patients. MATERIAL AND METHOD: A retrospective chart review was carried out for 12 patients aged over 80 years who underwent isolated OPCAB from January 2001 and March 2004. Data were collected risk factors for disease, extent of coronary disease, and in-hospital outcomes. Postoperative graft patency was evaluated in 9 patients by multi-slice computed tomography. RESULT: Eleven patients had triple vessel disease or left main disease. Four patients were suffered from preoperative CVA, and 4 patients had chronic obstructive pulmonary disease. Two patients had myocardial infarction (MI), among them 1 patient was suffered from pulmonary edema after preoperative MI. There was no perioperative death, perioperative MI, and no ventricular arrhythmia. Also there was no perioperative stroke and renal failure. But there was one deep sternal infection who recovered by treating of muscle flap. Atrial fibrillation was newly developed in 1 patient, but was well controlled by medication. Mean intubation time was 15.9+/-4.4 (8~20 hrs) hrs and mean ICU stay was 2.9+/-0.8 (2~4 days) days. Mean hospital day was 21.6+/-14.3 (13~56 days) days. Postoperative mean CK-MB was 11.3+/-14.1 ng/mL. Early postoperative graft patency rate was 100% (24/24). Follow-up was completed in all patients. In this time, there was no patients with angina or death. CONCLUSION: The results of this study suggest that OPCAB reduces morbidity and favors hospital outcomes. Therefore, OPCAB is safe, reasonable and might be preferable operative strategy in elderly patients.

Total Arterial Off-Pump Coronary Revascularization with Multiple Y Arterial Composite Grafts / 대한흉부외과학회지

BACKGROUND: Complete arterial off-pump coronary artery bypass grafting (OPCAB) by sequential anastomoses with one or two arterial grafts provides favorable outcomes. However, problems of insufficient graft length, hypoperfusion, kinking of graft, and unfavorable course of graft may be encountered. To solve these problems, we have used different technique with multiple arterial Y composite graft to allow end-to-side rather than sequential anastomoses and evaluated the results of this method. MATERIAL AND METHOD: Between February 2003 and October 2004, 71 patients underwent total arterial OPCAB using multiple arterial Y composite grafts with left internal mammary artery (LIMA), radial artery (RA), and right internal mammary artery (RIMA). We divided RA into multiple segments by number of distal target site after measuring of individual proper length and constructed arterial composite graft. One of segments was sutured end-to-side to LIMA and other segment was sutured end-to-side to the previously constructed radial graft. Postoperative graft patency was evaluated in 61 patients by multi-slice computed tomography. RESULT: An average of 2.5+/-0.6 arteries and 3.7+/-0.7 distal anastomoses per patient were done. There was no perioperative myocardial infarction, clinical hypoperfusion syndromes, and operative mortality. Postoperative mean CK-MB level was 17.4+/-29.7 IU/L. Overall graft patency was 99.1% (214/216)(LIMA: 100%, RA: 98.4%, RIMA: 100%). CONCLUSION: This technique allows total arterial OPCAB without technical problems and provides excellent early clinical results and graft patency. We believe that this technique is more convenient in the obtuse marginal area compared to sequential technique, and helpful in patients who require complex arterial grafting.

Off Pump Total Arterial Myocardial Revascularization / 대한흉부외과학회지

BACKGROUND: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. MATERIALS AND METHOD: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of 59.3+/-11.9 years (36~83). Mean ejection fraction was 55.4+/-14.0% (15~86). Angiography showed left main disease or triple-vessel disease in 81.9% of the patients. Indications of using arterial conduits was stenosis > or =50% of left anterior descending artery, stenosis > or =80% of branches of left circumflex artery, and stenosis > or =90% of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. RESULT: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were 2.86+/-0.78. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients (1.8%), renal failure in 4 patients (1.2%), perioperative myocardial infarction in 3 patients (0.9%), reoperation for bleeding in 3 patients (0.9%). There was no postoperative stroke. Patency rate of arterial conduits was 99.3% (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. CONCLUSION: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

The Comparison of Clinical Outcomes of Off-Pump versus On-Pump Coronary Artery Bypass Grafting in High Risk Patients / 대한흉부외과학회지

Background: Off-pump coronary artery bypass grafting (Off-Pump CABG) has been proven to have less morbidity and to facilitate early recovery. High-risk surgical patients may have benefitted by avoiding the adverse effects of the cardiopulmonary bypass. We compared the effectiveness of Off-Pump CABG with that of coronary artery bypass using cardiopulmonary bypass (On-Pump CABG) in high-risk patients. Material and Method: 682 patients (424 Off-Pump CABG and 258 On-Pump CABG) underwent isolated coronary artery bypass grafting between January 200l and June 2003. Patients who were considered high risk were selected High risk is defined as the presence of one or more of nine adverse prognostic factors. Data were collected from 192 patients in Off-Pump CABG and 100 in On-Pump CABG for risk factors, extent of coronary disease, and in-hospital outcomes. Result: Off-Pump CABG group and On-Pump CABG group did not show differences in their preoperative risk factors. We used more arterial grafts in Off-Pump CABG group (p<0.05). Postoperative results showed that operative mortality (0.5% in Off-Pump CABG versus 2.0% in On-Pump CABG), renal failure (2.6% in Off-Pump CABG versus 7.0% in On-Pump CABG), and perioperative myocardial infarction (l.5% in Off-Pump CABG versus l.0% in On-Pump CABG) did not differ significantly. However, Off-Pump CABG had shorter mean operation time (p<0.05), lower mean CK-MB level (p<0.05), lower rate of usage of inotropics (p<0.05), shorter mean ventilation time (p<0.05), lower perioperative stroke (0% versus 2.0%), and shorter length of stay (p<0.05) than On-Pump CABG. On-Pump CABG had more distal grafts (p<0.05) than Off-Pump CABG. Although Off-Pump CABG and On-Pump CABG did not show statistical differences in mortality and morbidity was more frequent in CABG. Conclusion: Off-Pump CABG reduces morbidity and favors hospital outcomes. Therefore, Off-Pump CABG is safe, reasonable and may be a preferable operative strategy for high-risk patients.

Surgical Treatment of Varicose Vein - TIPP(Transilluminated Powered Phlebectomy / 대한흉부외과학회지

The present study was done to determine the efficacy and safety of varicose vein removal using a minimally invasive, powered vein-extracting device with cutaneous transillumination and tumescent anesthesia techniques and then compared this to a retrospective group of conventional phlebectomy operations. There were 133 limbs in 104 patients(72 women, 32 men) treated with the use of the vein extractor aided by transcutaneous illumination. The hydrodissection was performed with TrivexTM Irrigated Illuminator(Smith and Nephew ) system using normal saline after the 2~3mm sized skin incision. Varicose clusters were extracted by the use of TrivexTM Resector(Smith and Nephew ) system under transillumination. After the varisoce vein extraction, the operation area was compressed with surgical pad for bleeding control. The complication rate was 3.84%. The mean number of incisions was 3.24 and mean operative time per limb was 65.9 minutes. The mean hospitalization was 1.86 days. The varicose vein extraction using transilluminated powered phlebectomy(TIPP) is a safe, efficacious and cosmetically satisfactory method. The procedure decreases the operating time and the number of incisions repuired to remove varicose clusters. Further evaluation and long term follow up will be necessary to determine the recurrence rate and long term complications.

Bilateral Sequential Single Lung Transplantation for Eisenmenger's Syndrome / 대한흉부외과학회지

Eisenmenger's syndrome is the disease of right to left shunt developing from the increased pulmonary vascular resistance caused by excessive pulmonary blood flow in patients with abnormal connections of systemic to pulmonary blood passage. The heart-lung transplantation was the only curative method in early transplantation period, but good results after bilateral lung transplantation have been reported as the fact that right heart function improved by only lung transplantation. We successfully carried out bilateral sequential single lung transplantation in a 34-year-old female patient with Eisenmenger's syndrome with large PDA. We report this case with a brief review of the literature.

Bilateral Sequential Single Lung Transplantation for Eisenmenger's Syndrome / 대한흉부외과학회지

Eisenmenger's syndrome is the disease of right to left shunt developing from the increased pulmonary vascular resistance caused by excessive pulmonary blood flow in patients with abnormal connections of systemic to pulmonary blood passage. The heart-lung transplantation was the only curative method in early transplantation period, but good results after bilateral lung transplantation have been reported as the fact that right heart function improved by only lung transplantation. We successfully carried out bilateral sequential single lung transplantation in a 34-year-old female patient with Eisenmenger's syndrome with large PDA. We report this case with a brief review of the literature.

Treatment of Vasodilatory Shock after Cardiac Surgery:Low Dose Arginine Vasopressin Therapy: Three cases report / 대한흉부외과학회지

The vasodilatory shock after cardiopulmonary bypass is defined as the condition involving severe and persistent form of hypotension, tachycardia, normal or increased cardiac output and decreased systemic vascular resistance. Because of the unsuccessful response to infusion of fluids or catecholamine vasopressors, a sustained systemic shock state occurs and results in a high morbidity and mortality. We successfully treated this syndrome of 3 patients after open heart surgery with low dose of arginine vasopressin(AVP). Therefore,we report these cases with a review of related articles.

Tracheal augmentation with Bovine pericardium / 대한흉부외과학회지

This case describes a tracheal stenosis complicated by endobronchial truberculosis. A 50-year-old female with progressive dyspnea was referred to us for the management of long segmental tracheal stenosis. Treatment modalities for tracheal stenosis include open surgical resectin and reconstruction, mechanical dilation, laser resection, and placement of an airway prosthesis. The following is a report of a successful treatment of a long segmental tracheal stenosis through a tracheal augmentation and the use of al Bovine pericardium. This technique may provide a relief from tracheal stenosis.

Hyperhidrosis Treated by Thoracoscopic Sympathicotomy / 대한흉부외과학회지

BACKGROUND: Hyperhidrosis of the palms, axillae and face has a strong negative impact on social and professional life. The present existing non-operative therapeutic options seldom give sufficient relief and have a transient effect. A definitive cure can be obtained by upper thoracic sympathectomy. However, this is offset by the occurrence of a high rate of side effects, such as embarrassing compensatory sweating. MATERIAL AND METHOD: From Sep. 1997 to Feb. 1998, 89 cases of the needle(2 mm) thoracoscopic thoracic sympathicotomy were performed. The second thoracic ganglion was resected by cutting with a endoscissors. RESULT: A bilateral procedure takes less than 25 min and requires just one night in hospital. There have been no mortality or life-threatening complications. One patient(<2%) required intercostal drainage because of pneumothorax. Primary failure occurred in one cases(<2%) and recurrent hyperhidrosis occurred in no cases. The patients with failure was successfully re-sympathicotomy. At the end of postoperative follow-up(median 3 months), 96.6% of the patients were satisfied. Compensatory sweating occurred in 57 cases(64.0%) with fourteen of those cases classified as either embarrassing in 10 cases(11.2%) or disabling in 4 cases(4.5%). CONCLUSION: Endoscopic transthoracic sympathicotomy is an efficient, safe and minimally invasive surgical method for the treatment of palmar and craniofacial hyperhidrosis.

According to Extent of Sympathectomy, Compensatory Hyperhidrosis in Essential Hyperhidrosis / 대한흉부외과학회지

BACKGROUND: Since 1992, we developed the technique for video endoscopic sympathectomy to treat palmar hyperhidrosis. It was soon proven to be a simple and effective therapy for essential hyperhidrosis. Compensatory hyperhidrosis, however, is the main cause of patient dissatisfaction after video-assisted thoracoscopic sympathectomy. According to many authors, initial satisfaction rate was high(94-98%), but it was declined with time (66%) due to mainly to embarrassing side effects. MATERIAL AND METHOD: From January 1992 to February 1998, the thoracoscopic T2 sympathicotomy, T2 sympathectomy and T2-4 sympathectomy were performed in 315 patients suffering from Essential hyperhidrosis in the Department of Thoracic and Cardiovascular Surgery in the Respiratory Center of Yongdong Severance Hospital Seoul, Korea. Eighty-nine patients underwent T2 sympathicotomy, and Eighty-eight patients underwent division T2 sympathectomy. RESULT: All of the treated patients obtained satisfactory alleviation of essential hyperhidrosis. The global rate of compensatory sweating were ; 64.0% in T2 sympathicotomy, 73.8% in T2 sympathectomy and 87.8% in T2-4 sympathectomy. The rate of embarrassing or disabling compensatory sweating was significantly higher in T2 sympathicotomy 15.7%(14/89) and in T2 sympathectomy 32.8%(28/88) than in T2-4 sympathectomy 58.0%(80/138) with significancy in statistic analysis(p<0.05). Video- assisted thoracoscopic sympathectomy is an effective minimally invasive and effective procedure. CONCLUSION: We suggest that the incidence and degree of compensatory hyperhidrosis was closely related to the extent of thoracic sympathectomy.

The Clinical Experiences of Patch Angioplasty in Isolated Critical Left Main Coronary Artery Stenosis / 대한흉부외과학회지

The conventional surgical treatment of isolated critical stenosis of the left main coronary artery restores a less physiologic perfusion of the myocardium, leads to occlusion of the left coronary ostium, and consumes an appreciable length of bypass material. From June 1994 to February 1996, eleven patients, three male and eight female, underwent patch angioplasty and additional bypass graft to left anterior descending artery (10 internal mammary artery, 1 saphenous vein) in isolated critical left main coronary artery stenosis. Their ages ranged from 34 to 62 years, mean 44 years. All had 60% to 90% stenosis of the left main coronary artery and Class III angina. The angiogram showed nine osteal lesion and three main stem stenosis. The operation was performed with conventional cardiopulmonary bypass and cold blood cardioplegia. We approached anteriorly and used bovine pericardium as onlay patch in all patients. There were one leg wound dehiscence, but no operative deaths and infarctions. All patients are free of symptoms after a mean follow-up of 15.5 months. Angiographic restudy at an average 14.4 months was obtained in five patients and showed widely patent left main coronary artery with excellent runoff. But additional graft to left anterior descending coronary artery were stenosed in two patients and showed diminutive flow in others. Our preliminary results suggest that angioplasty of the left main coronary artery can be carried out with low operative risks. But additional bypass graft to left anterior descending coronary artery may be unnecessary. The technique appears to be a promising alternative to conventional coronary artery bypass grafting in isolated left main coronary artery stenosis.

Prediction of Improvement of Hibernating Myocardium after Coronary Artery Bypass Grafting: The role of dobutamine stress echocardiography / 대한흉부외과학회지

BACKGROUND: In patients with coronary artery disease, dysfunctional hypoperfused myocardium at rest may represent either nonviable or viable hibernating myocardium. Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia by dobutamine infusion. The purpose of the present study was to identify the prediction of improvement of regional left ventricular (LV) function after surgical revascularization. MATERIALS AND METHODS: Sixteen patients with chronic regional LV dysfunction underwent dobutamine stress echocardiography (DSE) (dobutamine: baseline, 5, 10, 20microgram/kg/min) before coronary artery bypass grafting (CABG) and underwent echocardiography at least 2 months after CABG. RESULTS: All patients were male with mean age of 58 years ranging from 42 to 73 years. The mean LV ejection fraction was 41.8% with a range from 19% to 55%. During DSE, there were no complications, also, there were no operative morbidities or mortalities. Improvement of wall motion within the dysfunctional myocardium was found in 8 (50%) of 16 patients in DSE. Among them, 6 patients (75%) showed functional recovery after CABG. Another 8 patients did not show improvement of wall motion in DSE. But among them, 3 patients (38%) showed functional recovery after CABG. 84 dysfunctional segments were found in 256 segments of 16 patients. Improvement of wall motion was found in 34 of 84 segments in DSE. Among them, 23 segments (74%) showed functional recovery after CABG. Another 53 segments did not show improvement of wall motion in DSE. But among them, 12 segments (23%) showed functional recovery after CABG. The sensitivity and specificity of DSE for the prediction of postoperative improvement of segmental wall motion were 66% and 84%, respectively. The positive and negative predictive value of DSE were 74% and 77%, respectively. In patients with chronic regional LV dysfunction, think that DSE is a good predictor of the improvement of dysfunctional segments after CABG.

Development of an Occluder Device for Closure of Patent Ductus Arteriosus

BACKGROUND: Surgical correction of patent ductus arteriosus (PDA) is relatively safe and effective since it does not remain in the category of open-heart-surgery. Although the surgical practice for PDA is performed in almost all hospitals, they contain the problems of anxiety of patients, remained surgical wounds on patients' chests and complications of surgery and general anesthesia. Recently non-surgical methods for the obstruction of PDA have been developed and some of them including buttoned devices are used now. The success rates of these methods approach to 84%. But the problems of embolization, incomplete closure, hemolysis, stenosis of aorta and left pulmonary artery have been reported. We invented new PDA occluder , using stainless steel wire and polyurethane foam. Therefore we investigated the efficacy of occluding blood flow with the new PDA occluder in the vessels of experimental animals. METHOD: Using 304 stainless steel wire which is self-expandable stent, two star-shaped frames were made, each frame forming cone and facing the other's tip. And in the center of the frames polyurethane foam was inserted. 316L stainless steel wire was used to fix the elements described above and some portion of the wire was extracted outside of the frames, shaping hook or round loop with which the occluder could be pulled out in case of misplacement. To create the similar situation to PDA, we made shunts from artery to vein between carotid arteries and jugular veins with surgical bypass grafts or made shunts of direct artery to vein connections without grafts in 4 dogs and 1 pig. Through 8F sheath, we deployed the occluders into the shunts made of 5 grafts or made of 3 arterial ends. Also the occluders were inserted into the femoral artery of dog and iliac artery of pig. After deployment of occluders, angiograms were performed to obscure the efficacy of blocking blood flow and follow-up angiogrms were done in one and two weeks. The animals were sacrificed in one and two weeks to get the tissues including occluders inside. Gross findings were checked about thrombi formation in and around polyurethane foam. RESULTS: The 10 occluders were placed successfully except one site due to misplacement. The occluders successfully blocked the blood flows in all 10 sites within 3 - 60 minutes. Each follow-up angiogram for occluders in one and two weeks revealed good maintenance of blockade in blood flow. Observed gross findings on tissues were packed thrombi formation in the polyurethane foam and membrane formation along the occluder. CONCLUSIONS: This newly developed device revealed good efficacy for occlusion of blood flow including shunts in immediate and follow-up study. Practical method for the delivery of the device and some design modification for proper fitting into the PDA especially for small patients would be required. Longer period of follow-up with more animal experiments for other possible complications including distal embolization would be required also before clinical trial.

The Comparison of Protective Effects of Adenosine Included Cardioplegia According to Adenosine Dosage / 대한흉부외과학회지

BACKGROUND: Adenosine is secreted by myocardial cells during myocardial ischemia or hypoxia. It has many beneficial effects on arrhythmias, myocardial ischemia, and reperfusion ischemia. Although many investigators have demonstrated that cardioplegia that includes adenosine shows protective effects in myocardial ischemia or reperfusion injury, reports of the optimal dose of adenosine in cardioplegic solutions vary. We reported the results of beneficial effects of single dosage (0.75 mg/Kg/min) adenosine by use of self-made Langendorff system. But it is uncertain that dosage was optimal. The objective of this study is to determine the optimal dose of adenosine in cardioplegic solutions. MATERIAL AND METHOD: We used a self-made Langendorff system to evaluate the myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest (15degree C) with modified St. Thomas' Hospital cardioplegia including adenosine. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegia. Three groups of hearts were studied: (1) group 1 (n=10) : adenosine -0.5 mg/Kg/min, (2) group 2 (n=10): adenosine -0.75 mg/Kg/min, (3) group 3 (n=10) : adenosine -1 mg/Kg/min. RESULT: Group 3 resulted in a significantly rapid arrest time of the heart beat (p<0.05) but significantly slow recovery time of the heart beat after reperfusion (p<0.05) compared to groups 1 and 2. Group 2 showed a better percentage of recovery (p<0.05) in systolic aortic pressure, aortic overflow volume, coronary flow volume, and cardiac output compared to groups 1 and 3. Group 1 showed a a better percentage of recovery (p<0.05) in the heart rate compared to the others. In biochemical study of drained reperfusates, CPK and lactic acid levels did not show significant differences in all of the groups. CONCLUSION: We concluded that group 2 [adenosine (0.75 mg/Kg/min) added to cardioplegia] has better recovery effects after reperfusion in myocardial ischemia and is the most appropriate dosage compared to group 1 and 3.