Risk Factors of On-Pump Conversion during Off-Pump Coronary Artery Bypass Graft

BACKGROUND: Off-pump coronary artery bypass grafting (OPCABG) procedures can avoid the complications of an on-pump bypass. However, some cases unexpectedly require conversion to cardiopulmonary bypass during OPCABG. The risk factors associated with a sudden need for cardiopulmonary bypass were analyzed. METHODS: This retrospective study included 283 subjects scheduled for OPCABG from 2001 to 2010. These were divided into an OPCABG group and an on-pump conversion group. Preoperative, operative, and postoperative variables were compared between the 2 groups. RESULTS: Of the 283 patients scheduled for OPCABG, 47 (16%) were switched to on-pump coronary artery bypass grafting (CABG). The mortality of the both the OPCABG and on-pump conversion groups was not significantly different. The major risk factors for conversion to on-pump CABG were congestive heart failure (CHF) (odds ratio [OR], 3.5; p=0.029), ejection fraction (EF) <35% (OR, 4.4; p=0.012), and preoperative beta-blocker (BB) administration (OR, 0.3; p=0.007). The use of intraoperative (p=0.007) and postoperative (p=0.021) inotropics was significantly higher in the conversion group. The amount of postoperative drainage (p<0.001) and transfusion (p<0.001) also was significantly higher in the conversion group. There were no significant differences in stroke or cardiovascular complications between the groups over the course of short-term and long-term follow-up. CONCLUSION: Patients who undergo OPCABG and have CHF or a lower EF (<35%) are more likely to undergo on-pump conversion, while preoperative BB administration could help prevent conversions from OPCABG to on-pump CABG.

Clinical Effect of Left Ventricular Dysfunction in Patients with Mitral Stenosis after Mitral Valve Replacement

BACKGROUND: Mitral stenosis (MS) remains one of the important heart diseases. There are many factors that influence the clinical outcomes, and little is known about how left ventricular (LV) dysfunction clinically affects the prognosis of the patient with MS after mitral valve replacement (MVR). We reviewed our clinical experiences of MVR in patients with MS who had LV dysfunction. METHODS: Between January 1991 and January 2013, 110 patients with MS who underwent MVR were analyzed and divided into two groups according to ejection fraction (EF). Group 1 (EF≤45%) included 13 patients and group 2 (EF>45%) included 97 patients. RESULTS: Thromboembolism occurred in 8 patients after MVR (group 1: n=3, 23.1%; group 2: n=5, 5.2%) and its incidence was significantly higher in group 1 than in group 2 (p=0.014). There were 3 deaths each in groups 1 and 2 during follow-up. The overall rate of cardiac-related death in group 1 was significantly higher than in group 2 (group 1: n=3, 23.1%; group 2: n=3, 3.1%; p=0.007). The cumulative survival rate at 1 and 15 years was 83.9% and 69.9% in group 1 and 97.9% and 96.3% in group 2 (p=0.004). The Cox regression analysis revealed that survival was significantly associated with postoperative stroke (p=0.011, odds ratio=10.304). CONCLUSION: This study identified postoperative stroke as an adverse prognostic factor in patients with MS after MVR, and as more prevalent in patients with LV dysfunction. Postoperative stroke should be reduced to improve clinical outcomes for patients. Preventive care should be made in multiple ways, such as management of LV dysfunction, atrial fibrillation, and anticoagulation.

Right Coronary Artery to Left Ventricular Fistula with Giant Right Coronary Artery Aneurysm / 대한내과학회지

A 35-year-old male with exertional dyspnea was transferred to our hospital for evaluation of a diastolic murmur and cardiomegaly discovered by chest X-ray. Two-dimensional and Doppler echocardiographic studies revealed an aneurysmal dilation of the right coronary artery (RCA) and diastolic inflow from the RCA to the left ventricle (LV) through a myocardial defect 11 mm in diameter in the basal inferior LV wall. Coronary computed tomography angiography (CCTA) confirmed the presence of a giant RCA to LV fistula. Due to the risks for developing overt left heart failure and spontaneous rupture of the giant RCA, the RCA was obliterated surgically. Coronary-cameral fistulas are a rare congenital coronary artery anomaly. A fistula between the coronary artery and LV, especially when combined with coronary artery aneurysm, is a rare occurrence in the literature. Here, we report a case of a giant RCA to LV fistula detected by echocardiography and CCTA.

A Rare Cause of Secondary Hypertension in A Young Adult

Reninoma is a rare, renin-secreting, benign renal neoplasm that can cause secondary hypertension. We report a case of a 21-year-old man who suffered from progressively worsening headache for 2 months with a history of hypertension for 7 years. Laboratory studies showed normal potassium level, increased basal plasma renin activity, and normal serum aldosterone level. Abdominal computed tomography and magnetic resonance imaging revealed a small mass in the middle region of the right kidney. Partial nephrectomy was performed; immunohistochemical results demonstrated typical features of reninoma. Postoperatively, blood pressure and potassium level were normal at the 2-month follow-up.

Zanamivir Oral Delivery: Enhanced Plasma and Lung Bioavailability in Rats

The objective of this study was to enhance the oral bioavailability (BA) of zanamivir (ZMR) by increasing its intestinal permeability using permeation enhancers (PE). Four different classes of PEs (Labrasol(R), sodium cholate, sodium caprate, hydroxypropyl beta-cyclodextrin) were investigated for their ability to enhance the permeation of ZMR across Caco-2 cell monolayers. The flux and Papp of ZMR in the presence of sodium caprate (SC) was significantly higher than other PEs in comparison to control, and was selected for further investigation. All concentrations of SC (10-200 mM) demonstrated enhanced flux of ZMR in comparison to control. The highest flux (13 folds higher than control) was achieved for the formulation with highest SC concentration (200 mM). The relative BA of ZMR formulation containing SC (PO-SC) in plasma at a dose of 10 mg/kg following oral administration in rats was 317.65% in comparison to control formulation (PO-C). Besides, the AUC0-24 h of ZMR in the lungs following oral administration of PO-SC was 125.22 +/- 27.25 ng hr ml(-1) with a Cmax of 156.00 +/- 24.00 ng/ml reached at 0.50+/-0.00 h. But, there was no ZMR detected in the lungs following administration of control formulation (PO-C). The findings of this study indicated that the oral formulation PO-SC containing ZMR and SC was able to enhance the BA of ZMR in plasma to an appropriate amount that would make ZMR available in lungs at a concentration higher (>10 ng/ml) than the IC50 concentration of influenza virus (0.64-7.9 ng/ml) to exert its therapeutic effect.

A Case of Right Sinus of Valsalva Rupture with Dissection into Interventricular Septum Causing Left Ventricular Outflow Tract Obstruction

Sinus of Valsalva aneurysm (SVA) is an uncommon anomaly of the aorta. Rupture of SVA often precipitates dramatic clinical complications, including heart failures. Right SVAs are the most common type, and when they rupture, they usually rupture into the right ventricle or right atrium. Rupture into left ventricle or interventricular septum is rare. Herein, we report a case of right SVA rupture with dissection into interventricular septum, which produced significant left ventricular outflow tract obstruction and aortic regurgitation. The case was successfully treated by surgical operation.

A Case of Right Sinus of Valsalva Rupture with Dissection into Interventricular Septum Causing Left Ventricular Outflow Tract Obstruction

Sinus of Valsalva aneurysm (SVA) is an uncommon anomaly of the aorta. Rupture of SVA often precipitates dramatic clinical complications, including heart failures. Right SVAs are the most common type, and when they rupture, they usually rupture into the right ventricle or right atrium. Rupture into left ventricle or interventricular septum is rare. Herein, we report a case of right SVA rupture with dissection into interventricular septum, which produced significant left ventricular outflow tract obstruction and aortic regurgitation. The case was successfully treated by surgical operation.

Outcomes of Mitral Valve Repair: Quadrangular Resection versus Chordal Replacement

BACKGROUND: Mitral valve repair for posterior mitral leaflet (PML) prolapse has been considered to be a standard treatment because of its high success rate and high level of patient satisfaction. The aim of this study was to evaluate the clinical results of two different techniques of PML prolapse, quadrangular resection (QR) and chordal replacement (CR). MATERIALS AND METHODS: The subjects consisted of 56 patients who had undergone mitral valve repair for PML prolapse between November 1997 and December 2010. The patients were divided into two groups according to surgical technique. Among them, 31 patients underwent QR (group QR) and 25 patients had CR (group CR). We reviewed the medical records of the patients retrospectively to compare the clinical outcomes of both groups. RESULTS: After mitral valve repair, the degree of mitral regurgitation (MR) in both groups decreased to the to a mild degree or less and the amount of remnant MR was slightly higher in the CR group but it was not statistically different. Three patients received mitral valve-related reoperation (2 in the QR group and 1 in the CR group). Freedom from mitral valve-related reoperation at 7 years was 93% for the QR group and 96% for the CR group and was not significantly different between the two groups. CONCLUSION: Both QR and CR showed excellent long-term results and were considered equally effective methods for PML prolapse.

Left Atrial Myxoma Presenting with Unusual Cystic Form

Cardiac myxomas are the most common primary benign tumors of uncertain etiology. They usually present as polypoid or oval-shaped masses projecting into a heart chamber from the interatrial septum and have a soft, gelatinous consistency without a cystic structure. We report a case of left atrial myxoma with a single cystic form.

Continuous "Over and Over" Suture for Tricuspid Ring Annuloplasty

BACKGROUND: A ring implantation in the tricuspid annulus requires many interrupted mattress sutures for correction of tricuspid regurgitation (TR). In this study, tricuspid ring annuloplasty was performed by 2-0 polypropylene continuous suture instead of multiple interrupted 2-0 polyester mattress sutures, and the efficacy of the method was evaluated. MATERIALS AND METHODS: This study included 20 patients who underwent tricuspid ring annuloplasty by continuous suture between May 2009 and July 2010. Four of the patients had an isolated TR, and the rest had a left-sided cardiac lesion. The concomitant tricuspid annuloplasty was performed after the left-sided heart surgery was completed and a Duran flexible ring prosthesis was used. RESULTS: There was no perioperative mortality or conduction problem. More than a moderate degree of TR was improved to less than a mild degree after the procedure. After the ring annuloplasty, the right atrial volume decreased from 123.7+/-69.2 mL to 74.5+/-37.4 mL, and the mean right atrial pressure was lowered from 18.7+/-12.2 mmHg to 8.9+/-5.5 mmHg. CONCLUSION: The continuous "over and over" suture may be a useful procedure for fixing the ring to the annulus and making an intentional annular placation in performing tricuspid ring annuloplasty.

Clinical Experience of the Surgical Treatment of Cardiac Tumor / 대한흉부외과학회지

BACKGROUND: Primary cardiac tumors are extremely rare. The most common type are benign myxomas, and these are almost completely curable with early surgery. Malignant tumors, however, such as sarcomas, are difficult to remove surgically, and their prognosis is known to be poor. In this study, data on patients who had undergone surgical treatment of cardiac tumor in the authors' hospital were collected and analyzed. MATERIAL AND METHOD: The subjects included 28 patients who had undergone surgical treatment of cardiac tumor from August 1993 to December 2008. Their medical records were reviewed and retrospectively analyzed. RESULT: The patients were aged from 20 to 76 years (mean age: 54.2+/-15.6), and 11 were male (39%) and 17 female (61%). Fifteen of them (54%) underwent emergency surgery to improve heart failure symptoms. The most common preoperative symptom was dyspnea (15 cases, 54%). Preoperative echocardiography was performed on all the patients. The average size of the tumor as measured during the operation was 7.0+/-6.9 cm (the average length of the long axis was 2~40 cm), and the sites of tumor attachment were the interatrial septum (18 cases, 64%), the left atrium (9 cases, 32%), the mitral valve annulus (2 cases, 7%), and the left ventricle (2 cases, 7%). The operation was performed with an incision through both atria in all the patients, and a complete excision was made in 25 cases (89%). According to the biopsy results, there were 4 cases of sarcoma (14%), 1 case of lipoma (4%), and 23 cases of myxoma (82%). The three cases in which the tumors were not completely excised were sarcomas. No operative deaths occurred after the operations. Outpatient follow-up was possible for 24 cases (86%), with a mean follow-up period of 46.8+/-42.7 months. Late death occurred in 3 of the 24 patients; each of these patients had sarcomas. Of these patients, the first had undergone two repeat surgeries, the second had metastatic sites removed, and the last had only chemotherapy. The average recurrence time was 12.7+/-10.8 months, and the average metastasis time was 20.5+/-16.8 months. CONCLUSION: Most cardiac tumors are benign myxomas. In principle, they should be surgically treated because they can create risks such as embolism, and can be radically treated when surgically removed. In most cases, however, malignant sarcomas are already considerably advanced with severe infiltration into the neighboring tissues at the time of diagnosis. The surgical removal of malignant sarcomas is known to be difficult because of the advanced stage and degree of infiltration. We suggest that excision of the removable portion of the tumor sites to alleviate symptoms such as heart failure can improve quality of life.

The Clinical Outcome of Pulmonary Thromboendarterectomy for the Treatment of Chronic Pulmonary Thromboembolism / 대한흉부외과학회지

BACKGROUND: Diagnosing chronic pulmonary embolism at an early stage is difficult because of the patient's non-specific symptoms. This condition is not prevalent in Korea, and in fact, there have been only a few case reports on this in the Korean medical literature. We analyzed the surgical outcome of performing pulmonary thromboendarterectomy in patients with chronic pulmonary embolism. MATERIAL AND METHOD: The study subjects included those patients who underwent surgery for chronic pulmonary embolism from 1996 to 2008. For making the diagnosis, echocardiography, chest CT and a pulmonary perfusion scan were performed on the patients who complained of chronic dyspnea. RESULT: Pulmonary endarterectomy was performed as follows: by incision via a mid-sternal approach (7 patients); by incision via a left posterolateral approach (1 patient); using the deep hypothermic circulatory arrest technique (4 patients); under ventricular fibrillation (3 patients); and under cardioplegic arrest (1 patient). The postoperative systolic pulmonary artery blood pressure significantly decreased from a preoperative value of 78.9+/-14.5 mmHg to 45.6+/-17.6 mmHg postoperatively (p=0.000). The degree of tricuspid regurgitation was less than grade II after surgery. Two patients died early on, including one patient who had persistent pulmonary hypertension without improvement and right heart failure. CONCLUSION: Patients who have chronic pulmonary embolism are known to have a poor prognosis. However, we think that early surgical treatment along with making the proper diagnosis before the aggravation of right heart failure can help improve the quality of a patient's life.

Clinical Study of Composite Valve Graft Replacement of the Aortic Root / 대한흉부외과학회지

BACKGROUND: A composite valve graft replacement has been used for a variety of aortic root diseases. The aim of this study was to evaluate the mid-term results of this technique. MATERIAL AND METHOD: We conducted a retrospective analysis of aortic root composite valve graft replacements in 39 patients and these procedures were done at our institution between 1992 and 2009. The mean age of the patients was 49.2+/-16.4 years. The mean follow-up was 64.2+/-53.4 months (maximum: 176 months). RESULT: There were 4 hospital deaths (8.6%) due to emergency aortic dissection and 4 late deaths owing to several causes. The causes of late death were 2 ruptures of a remnant aneurysm, 1 subdural hemorrhage and 1 paravalvular leakage. The calculated survival rate was 93.5%, 85.0% and 85.0% at 1, 5 and 10 years, respectively. There were 3 cerebrovascular accidents during the follow up period. The rate of freedom from cerebrovascular accidents was 97.0%, 92.0% and 80.0% at 1, 5 and 10 years, respectively. All of these brain accidents were hemorrhage-related complications. CONCLUSION: A composite valve graft replacement of the aortic root was associated with favorable results. So, this technique seems to be a good method to treat various aortic root diseases.

Obturator Bypass Surgery in a Patient with an Infected Femoral Artery Rupture after Performed ECMO: A case report / 대한흉부외과학회지

Infection of both native and prosthetic vessels in the groin is a very serious disease because of recurrent arterial rupture and sepsis, which can cause death. The successful treatment of groin infection, including infection of the femoral artery, requires extensive excision of the infected tissues and restoration of the circulation where the infected area is isolated. Here we describe a case of obturator bypass in a patient with infected femoral artery rupture that occurred after extracorporeal membrane oxygenation for myocarditis and severe heart failure.

Robot-assisted Thymectomy with the 'da Vinci' Surgical System in a Patient with Myasthenia Gravis: A case report / 대한흉부외과학회지

In the treatment of myasthenia gravis, thymectomy is generally accepted as the standard of therapy. For thymectomy, there have been various conventional open approaches including sternal splitting, but recently minimally invasive approaches have been increasingly applied. A 28-year-old man presenting with weakness of both hands and fatigability was diagnosed as having myasthenia gravis with thymic hyperplasia. He underwent a robot-assisted thymectomy with the 'da Vinci' surgical system. Through the right thoracic cavity, two thirds of the thymic gland was dissected, and the remainder was resected through the left; these procedures took, respectively, 1 hour and 30 minutes. The patient was discharged on the 8th postoperative day without complications. The minimally invasive approach with the 'da Vinci' surgical system is emerging as a popular choice and various advantages have been reported. Here we report the first successful case of robot-assisted thymectomy.

Repair of Ruptured Papillary Muscle of the Tricuspid Valve as a Cause of Tricuspid Insufficiency Following Blunt Chest Trauma / 대한흉부외과학회지

A 47-year-old man presented with complaints of chest pain and dyspnea caused by deceleration injury due to an automobile accident. Systolic cardiac murmur was audible at the right sternal border. An electrocardiogram showed sinus tachycardia. Transthoracic echocardiography revealed a flailing anterior leaflet of the tricuspid valve, papillary muscle rupture, and severe valve insufficiency. Rupture of papillary muscle of the anterior leaflet and chordae tendineae of the posterior leaflet were confirmed by right atrial incision under routine cardiopulmonary bypass. Artificial chordae tendineaes were implanted between the anterior and posterior leaflet and papillary muscles in the right ventricles. De-Vega annuloplasty was also added. This is a very rare case in which a surgery was done for tricuspid valve regurgitation caused by post-traumatic papillary muscle rupture.

Surgical Experience of Pericardial Mesothelioma: 2 Cases / 대한흉부외과학회지

Cardiac mesotheliomas are rare. It is difficult to diagnose them at an early stage because the symptoms are nonspecific. Here we report two cases that had been initially diagnosed as constrictive pericarditis but later were definitively diagnosed, after pericardiectomy, as mesothelioma. The two patients complained of dyspnea that lasted 4 months and 10 years. Chest CT showed mild pericardial effusion and thickened pericardium, which was found enveloping the heart without any lumps. Median sternotomy showed that the overall pericardium was thickened by more than 10 mm. Pericardiectomy (phrenic nerve to phrenic nerve) was performed and post-operative histology confirmed malignant mesothelioma. In one patient the disease recurred near the pericardium post-operatively at 7 months and the patient died at 11 months. The other patient received chemotherapy and was still alive at post-operative month 16. Pericardial mesothelioma is an extremely rare disease exhibiting clinical signs similar to those of constrictive pericarditis, and should be diagnosed at an early stage of onset.

The Effect of Preoperative Clopidogrel on the Postoperative Bleeding after OPCAB / 대한흉부외과학회지

BACKGROUND: Clopidogrel is widely used just before coronary artery bypass surgery, yet its pharmacological effect can cause postoperative bleeding-related complications. The purpose of this study was to find the effect of preoperative clopidogrel exposure on the blood transfusion requirement and on the rate of reexploration for bleeding control and the rate of readmission caused by bleeding in patients who undergo off-pump coronary artery bypass surgery (OPCAB). MATERIAL AND METHOD: This study included 103 patients who had been on clopidogrel preoperatively and they underwent OPCAB by one surgeon from January, 2005 to November, 2007. We divided the patients into two groups. Group 1 consisted of 45 patients who stopped cloidogrel 5 days before surgery and group 2 consisted of 58 patients who were taking clopidogrel within 5 days before surgery. Two groups were compared in terms of the bleeding related reoperation rate and the readmission rate, the amount of postoperative bleeding and the required amount of transfusion. RESULT: There were no significant differences between the two groups concerning the demographic, echocardiographic and hematologic features. There were no significant differences in the postoperative bleeding amount, but the amount of required transfusion was greater in group 2 (p=0.018). While group 1 showed a 0% reoperation rate for hemostasis and a 0% readmission rate as related to postoperative bleeding, group 2 showed a 6.9% reoperation rate and a 5.2% readmission rate, but there were no statistically significant differences between the two groups. CONCLUSION: Continuous use of clopidogrel did not cause postoperative major bleeding, but it can increase the amount of bleeding and the amount of required transfusion postoperatively. We think that discontinuation of clopidogrel for a while before elective OPCAB can help the patient's postoperative recovery.

da Vinci Robot-Assisted Esophagectomy for Esophageal Cancer: A Case of Esophago-gastrostomy through the Retrosternal Route : A case report / 대한흉부외과학회지

Operations using the da Vinci robot have performed in for many surgeries, but the adoption of robotics to general thoracic surgery has been slow. The patient (age 74, male) visited our hospital complaining of hiccups and dysphagia. The CT scan and endoscopic biopsy revealed esophageal cancer (squamous cell carcinoma). We performed transthoracic esophagectomy using a da Vinci robot and this was followed by gastric tube mobilization via laparoscopy. Cervical esophago-gastric anastomosis was done using the hand-sewn method. The gastric tube was brought into the neck through the retrosternal route. The patient was discharged without any complications. We report here on a case of successful da Vinci robotic esophgagectomy.

The Long-term Results of a Modified Maze Procedure with Using Cryoablation / 대한흉부외과학회지

BACKGROUND: Atrial fibrillation is associated with several complications such as cerebro-vascular accidents and peripheral arterial embolism. Most of the patients who have this arrhythmia chronically feel their heart beating and so they are frightened; therefore, the quality of a patient's life is decreased. The purpose of this article is to determine the long term results of a modified Maze procedure and the factors that influence the success of the procedure. MATERIAL AND METHOD: This study enrolled 88 patients who underwent the modified Maze with using cryoablation between June, 2001 and February, 2007. The 88 consecutive patients were divided into two groups according to how the pulmonary veins were isolated, that is, with or without cryoablation. There were 58 patients who were isolated by cutting and sewing in the right pulmonary veins and by cyroablation in the left pulmonary veins in group 1 (group 1, n=58), and 30 patients who underwent isolation by cryoablation in the right & left pulmonary veins were placed in group 2 (group 2, n=30). The ECG was checked at discharge to determine the sinus conversion rate and we followed up the patients to determine whether or not the patients maintained sinus rhythm. We also checked the ECG at the last visit to determine the patients' heart rhythm. RESULT: The mean follow up time was 44.3+/-19.2 months. At discharge, 72.4% of the patients in group 1 were in proper sinus rhythm and 66.7% of the patients in group 2 were in proper sinus rhythm. At the last follow up, 81% of the patients in group 1 were in normal sinus rhythm and 60% of the patients in group 2 were in normal sinus rhythm. When we analyzed the data via the Kaplan-Meier method, 86.5% of the patients were free from atrial fibrillation (% free from AF) at 1 year, 80% of the patients were free from atrial fibrillation at 5 year in group 1 and 70% of the patients were free from atrial fibrillation at 1 year and 51% of the patients in group 2 were free from atrial fibrillation at 5 year. CONCLUSION: The modified Maze technique using cryoablation was a simple and effective procedure. But the success rate of the Maze technique using cryoblation is lower than that of the standard Maze III. The method using cryoablation shorten the operation time, but we must conduct more studies to get a better result of the modified Maze technique with using cryoablation.