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Cheong Lim

Publications and source records attributed to Cheong Lim.

16 recordsLinked to original sources
PubMed2006

One-stage total repair of aortic arch anomaly using regional perfusion.

OBJECTIVE: Primary repair of aortic arch obstructions and associated cardiac anomalies is a surgical challenge in neonates and infants. Deep hypothermic circulatory arrest prolongs myocardial ischemia and might induce cerebral and myocardial dysfunction. METHODS: From March 2000 to December 2005, 69 neonates or infants with aortic arch anomaly underwent one-stage biventricular repair with continuous cerebral perfusion in the presence of a nonworking beating heart using the dual perfusion technique on the innominate artery and aortic root. Preoperative diagnoses of arch anomaly comprised aortic coarctation (n=54) or an interrupted aortic arch (n=15). Combined anomalies were ventricular septal defect (n=52), anomalous origin of the right pulmonary artery from ascending aorta (n=3), hypoplastic left heart syndrome (n=2), truncus arteriosus (n=2), atrioventricular septal defect (n=2), double outlet right ventricle (n=1), total anomalous pulmonary venous return (n=1), partial anomalous pulmonary venous return (n=1), and aortic stenosis (n=1). RESULTS: The mean regional perfusion time was 27.8+/-9.8 min. There was no operative mortality. Postoperative low cardiac output was present in four patients (5.8%). A neurologic complication was noted in one patient (1.5%) who developed transient chorea, but recovered completely. During 32.8+/-17.5 months of follow-up, one late death (1.5%) occurred. There was neither reoperation associated with arch anomaly nor recoarctation except in one patient. One patient developed left main bronchial compression necessitating aortopexy. CONCLUSIONS: One-stage total arch repair using our regional perfusion technique is an excellent method that may minimize neurologic and myocardial complications without mortality. Our surgical strategy for arch anomaly has a low rate of residual and recurrent coarctation when performed in neonates and infants.

Aortic Arch Syndromes↗
PubMed2005

Surgical strategy for pulmonary coarctation in the univentricular heart.

OBJECTIVE: The placement of a modified Blalock-Taussig shunt in patients suffering from pulmonary coarctation can result in the aggravation of uneven pulmonary blood flow. This may subsequently obviate the possibility of future performance of the Fontan procedure. The objective of this study was to evaluate mid-term results in patients with pulmonary coarctation who had undergone the placement of a modified Blalock-Taussig shunt, coupled with a pulmonary artery angioplasty. METHODS: We retrospectively reviewed the records of 13 patients who had undergone the placement of a modified Blalock-Taussig shunt, coupled with concomitant pulmonary angioplasty, between September 1998 and August 2002. All patients received follow-up angiographic evaluations. RESULTS: On the ipsilateral side of the modified Blalock-Taussig shunt, we observed a significant increase in the pulmonary artery index during a mean follow-up period of 11+/-5 months (preoperative 82+/-37 mm2/m2, follow-up 129+/-57, p=0.03). On the contralateral side, we also observed a significant increase in the pulmonary artery index (preoperative 90+/-56 mm2/m2, follow-up 137+/-56, p=0.047). There was one late death. During the follow-up period (mean 23+/-18 months), 10 patients received either a bidirectional or total cavopulmonary shunt and five of these patients underwent extracardiac Fontan operations. CONCLUSIONS: Our study demonstrated that the placement of a modified Blalock-Taussig shunt, with concomitant pulmonary artery angioplasty, constitutes a good initial surgical strategy in cases of univentricular heart with pulmonary coarctation.

Anastomosis, Surgical↗
PubMed2005

Alternative Fontan connection for apicocaval juxtaposition.

We present an alternative technique to the modified Fontan procedure used in a 3-year-old boy who had complex heart defects with bilateral superior vena cava and apicocaval juxtaposition. The left superior vena caval pathway was used behind the ventricle to connect the inferior vena cava to the pulmonary artery. We proved the technical feasibility of this with good midterm results at the 5-year follow-up angiography.

Abnormalities, Multiple↗
PubMed2005

Management of left atrial endocardium after extensive thrombectomy.

Thrombosis at the left atrium is a common phenomenon in patients with chronic mitral valve disease and atrial fibrillation. When thrombus organizes and evolves into chronic phase, clean thrombectomy can become a challenge during heart surgery because of dense adhesions and the lack of clean cleavage plane. Leaving residual thrombotic material or roughened endocardial surface after thrombectomy could be a potential source for further thrombosis and a nidus for thromboembolism. We recently managed such a patient successfully using extensive thrombectomy and endocardial coverage with a fresh autologous pericardial patch.

Atrial Appendage↗
PubMed2005

Prediction of graft flow impairment by intraoperative transit time flow measurement in off-pump coronary artery bypass using arterial grafts.

BACKGROUND: We assessed the validity of intraoperative transit time flow measurement (TTFM) in predicting graft flow abnormalities. METHODS: Intraoperative graft flow measurement using TTFM and early postoperative coronary angiography was performed in 58 patients who underwent total arterial off-pump coronary artery bypass. Five variables (flow pattern, mean flow, pulsatility index, insufficiency ratio, and fast Fourier transformation ratio) were measured and compared between 103 normal and 14 abnormal (occluded or competitive) grafts. RESULTS: The grafts anastomosed to the right coronary territories showed significantly less diastolic dominant pattern, lower mean flow and fast Fourier transformation ratio, and higher pulsatility index than grafts to the left coronary artery territories (p < 0.05). None of the abnormal grafts showed a diastolic dominant flow pattern. The abnormal grafts demonstrated significantly lower mean flow and fast Fourier transformation ratio and higher pulsatility index and insufficiency ratio than normal grafts (p < 0.05). When our criteria for detection of abnormal graft flow, [(1) systolic dominant or balanced pattern of the flow curve in the left coronary territories, systolic dominant pattern of the flow curve in the right coronary territories; (2) mean flow < 15 mL/min; (3) pulsatility index > 3 in the left coronary territories and > 5 in the right coronary territories; and (4) insufficiency ratio > 2%] were applied, the sensitivity and specificity of TTFM to detect the graft flow abnormality were 96.2% and 76.9%, respectively. CONCLUSIONS: Our data suggest that TTFM is a reliable intraoperative tool to predict graft flow impairment.

Coronary Angiography↗
PubMed2004

Early replacement of pulmonary valve after repair of tetralogy: is it really beneficial?

OBJECTIVES: Debate on the proper timing of pulmonary valve replacement (PVR) after repair of tetralogy of Fallot (TOF) is still continuing. Significant pulmonary regurgitation (PR) could result in right ventricular (RV) dysfunction, exercise intolerance, arrhythmia, and sudden death. We analyzed clinical results of PVR after repair of TOF to investigate potential risk factor for late outcomes. METHODS: From January 1993 to July 2002, 58 patients (38 males and 20 females) received PVR after repair of TOF. More than moderate degree of PR was observed in these patients by echocardiography. Mean age at PVR was 13.5+/-9.6 years (1.2-44) and TOF repair was performed at 5.2+/-7.1 years of age (0.5-34). Therefore, PVR was performed at 8.3+/-5.2 years (4 months-28 years) after repair. Preoperative electrocardiogram showed complete right bundle branch block in 49 patients (84.5%). Mean duration of QRS complex was 142+/-30 ms. Major arrhythmia occurred in eight patients. Twenty-nine patients complained decreased physical activity and 10 patients showed clinical signs of right heart failure. RESULTS: Early death occurred in one patient (2.5%). Major complication occurred in three patients (complete heart block in two, aortic rupture in one). Follow-up was performed for 2.5+/-2.4 years (46 days-10.3 years). There was no late death. Postoperative cardiothoracic ratio was significantly decreased (0.61+/-0.07 to 0.55+/-0.06, P < 0.001). Marked symptomatic improvement was noted in all patients. Postoperative symptomatic group (n = 14) showed older age at repair of TOF (12.5+/-10.7 vs 2.6+/-2.3 years, P = 0.003), older age at PVR (23.2+/-12.8 vs 10.1+/-5.0 years, P = 0.001), longer interval between repair of TOF and PVR (10.6+/-7.0 vs 7.5+/-4.2 years, P < 0.05), higher degree of functional class (2.4+/-0.5 vs 1.4+/-0.8, P < 0.001), and longer duration of hospitalization (30.0+/-14.2 vs 18.9+/-11.4 days, P = 0.004) than postoperative asymptomatic group (n = 43). CONCLUSIONS: In patients with significant PR after repair of TOF, PVR had clinical benefits including symptomatic improvement with low mortality and morbidity. Proper timing must be carefully selected according to objective evaluation of RV function. In our study, earlier PVR prior to symptomatic manifestation showed beneficial effects.

Adolescent↗
PubMed2003

Staged biventricular repair of Taussig-Bing anomaly with subaortic stenosis and coarctation of aorta.

We present successful procedures for 2 infants who had the Taussig-Bing anomaly with subaortic stenosis and coarctation of the aorta. The initial procedure was coarctoplasty and the Damus-Kaye-Stansel procedure with modified Blalock-Taussig shunt. The second procedure was intraventricular repair (Kawashima procedure), Damus-Kaye-Stansel take-down and the reuse of native aortic and pulmonary valves 19 and 25 months later. Both patients survived the operations and postoperative hemodynamics were excellent at both 28 and 59 months follow-ups.

Aortic Coarctation↗
PubMed2003

Commissural malalignment of aortic-pulmonary sinus in complete transposition of great arteries.

BACKGROUND: Translocation of the coronary artery to the neoaorta is essential in the arterial switch operation. The goal of this study is to investigate (1) the frequency of commissural malalignment in complete transposition of the great arteries, (2) the usefulness of echocardiography in diagnosis of commissural malalignment, and (3) the impact of commissural malalignment on surgery. METHODS: We retrospectively reviewed the medical records of 28 patients with complete transposition of the great arteries who underwent an arterial switch operation from February 2000 to August 2001. RESULTS: Commissural malalignment was expected preoperatively in 11 patients by echocardiography and was confirmed in 13 patients intraoperatively. Four patterns of commissural malalignment were present: (1) sinus-facing of the pulmonary valve, (2) sinus-facing of the aortic valve, (3) sinus-facing of both valves, and (4) bicuspid pulmonary valve (functionally sinus-facing). Two patterns of severity were present: major and minor. To avoid torsion and stretching of the coronary arteries during surgery, various methods were needed: more extensive dissection of the coronary artery, trap door incision, supracommissural or juxtacommissural transfer, both coronary transfer to the same sinus, tube reconstruction of the coronary artery, and neoaorta dextrorotation anastomosis. One patient who had severe commissural malalignment died during the operation, and the cause of death was probably stretching or torsion of the coronary artery. CONCLUSIONS: The recognition of malalignment of the facing sinus in transposition of the great arteries can be detected preoperatively by echocardiography. The surgical procedure of the arterial switch operation is influenced by the presence of commissural malalignment. Preoperative awareness of commissural malalignment seems to be helpful for surgeons to predict the need for an alternative operational procedure.

Adolescent↗
PubMed2003

Aortic arch reconstruction using regional perfusion without circulatory arrest.

OBJECTIVES: Deep hypothermic circulatory arrest during repair of aortic arch anomalies may induce neurological complications or myocardial injury. Regional cerebral and myocardial perfusion may eliminate those potential side effects. METHODS: From March 2000 to March 2002, 48 neonates or infants with complex arch anomaly were operated on using the regional perfusion technique. Thirty-three patients were male and the median age was 24 days (range 5-301 days). Preoperative diagnosis consisted of coarctation or interruption of the aorta associated with ventricular septal defect (group I, n = 26) and arch anomaly with complex intracardiac defects such as hypoplastic left heart syndrome or its variants (group II, n = 22). Arterial cannula was inserted through the innominate artery and the flow rate was regulated to about 50-100 ml/kg per min during regional perfusion. Simultaneous myocardial perfusion was maintained using a Y-connected infusion line. Cardioplegia was applied during intracardiac repair. RESULTS: Cardiopulmonary bypass and aortic cross-clamp times were 154 +/- 49 and 39 +/- 34 min, respectively. Temporary circulatory arrest for intracardiac procedures was performed in eight patients. However, the mean arrest time was minimized (range 1-18 min). The descending aorta clamping time was 33 +/- 16 min. Operative mortality rates in each group were 0 and 18.2% (0/26 and 4/22). Late mortality rates were 0 and 11.1% (0/26 and 2/18) during 9.1 months of follow-up. Complications consisted of low cardiac output in eight cases, transient neurological problems in two cases, and transient renal insufficiency in two cases, respectively. CONCLUSIONS: Regional perfusion is feasible and can be used with acceptable results. It may reduce potential complications following aortic arch reconstruction using circulatory arrest. However, repair of aortic arch in the patients with complex intracardiac defects still imposes a significant rate of mortality and morbidity.

Aorta, Thoracic↗
PubMed2002

Bilateral skeletonized internal thoracic artery graftings in off-pump coronary artery bypass: early result of Y versus in situ grafts.

BACKGROUND: Use of bilateral skeletonized internal thoracic arteries (ITAs) in off-pump coronary artery bypass (OPCAB) retains several advantages that may eventually result in better patient outcomes. We compared the early results of OPCAB using bilateral ITAs as Y grafts with results of OPCAB using bilateral ITAs as in situ grafts. METHODS: A total of 223 consecutive patients who underwent OPCAB using bilateral skeletonized ITAs as Y grafts (group I, n = 113) or in situ grafts (group II, n = 110) were studied. RESULTS: Both the number of distal anastomoses per patient and the number of distal anastomoses per bilateral ITA were higher in group I (3.5 +/- 1.0 and 2.9 +/- 0.7) than in group II (3.0 +/- 0.7 and 2.4 +/- 0.5) (p < 0.01). Hospital mortality was 1.8% (2/113) in group I and 0.9% (1/110) in group II (p = ns). There were no differences in postoperative complications including atrial fibrillation (13.3% vs 10.9%), perioperative myocardial infarction (0.9% vs 2.7%), mediastinitis (0.9% vs 1.8%), and hypoperfusion syndrome (0.9% vs 0%) between groups I and II (p = ns). Postoperative coronary angiographies performed in 110 patients in group I and 108 patients in group II showed 99.0% (382/386) overall patency and 99.4% (319/321) patency for distal anastomoses using ITAs in group I, and 98.1% (312/318) overall patency and 98.1% (258/263) patency for distal anastomoses using ITA in group II. There were no significant differences in graft patency rates between the two groups (p = ns). CONCLUSIONS: Our results demonstrate that OPCAB using bilateral skeletonized ITAs is technically feasible, with excellent graft patency. Using bilateral skeletonized ITAs as Y grafts increases the number of distal anastomoses that can be performed and does not cause additional postoperative morbidity.

Atrial Fibrillation↗
PubMed2002

Truncus arteriosus with coarctation of persistent fifth aortic arch.

Truncus arteriosus is a rare form of congenital heart defect. Among cases, 10% to 20% are associated with arch anomalies, such as interruption, coarctation, or patent ductus arteriosus. We treated a rare case of combined truncus with complex arch anomaly. The patient was a 2-month-old girl weighing 3.8 kg. Echocardiogram and computed tomogram showed interrupted aortic arch, truncus arteriosus, persistent fifth aortic arch, and its coarctation. One-stage total correction was performed under cardiopulmonary bypass without circulatory arrest. The operation consisted of a Rastelli procedure with a 12-mm valved conduit, coarctoplasty, and intraventricular baffling. The patient recovered well without complications.

Aorta, Thoracic↗
PubMed2002

Off-pump coronary artery bypass with complete avoidance of aortic manipulation.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) with complete avoidance of aortic manipulation may further reduce perioperative morbidity in addition to the benefits achieved by avoiding cardiopulmonary bypass and cardioplegic arrest. METHODS: We prospectively analyzed 222 consecutive patients with multivessel disease who underwent OPCAB without aortic manipulation (group I), and compared them with 123 consecutive patients who underwent OPCAB using additional free arterial or saphenous vein grafts that were anastomosed on the ascending aorta (group II) and 76 consecutive patients who underwent on-pump conventional coronary artery bypass grafting (group III). RESULTS: No significant differences were noted in operative mortalities among the three groups (2/222, 3/123, and 2/76 in groups I, II, and III, respectively; p = NS). Fewer distal anastomoses were done in group I compared with groups II and III (3.2 +/- 0.9, 3.5 +/- 0.8, and 3.7 +/- 0.9 in groups I, II, and III, respectively; p < 0.001). No differences were noted in the incidences of postoperative morbidities such as mediastinitis, pulmonary complication, and reoperation for bleeding. The incidences of stroke, atrial fibrillation, and acute renal failure were significantly lower in group I than in group III (p < 0.05), although there were no significant differences between groups II and III. The incidence of perioperative myocardial infarction was significantly lower in group I than in groups II and III (p < 0.05), although there was no significant difference between groups II and III. CONCLUSIONS: Our results demonstrate that OPCAB with complete avoidance of aortic manipulation may further reduce the incidence of perioperative morbidities such as stroke, atrial fibrillation, acute renal failure, and perioperative myocardial infarction.

Acute Kidney Injury↗
PubMedDate not supplied

Delayed hyperenhancement by contrast-enhanced magnetic resonance imaging: Clinical application for various cardiac diseases.

The clinical applications of contrast-enhanced magnetic resonance (MR) imaging for defining viability are evolving as a result of the advantage of the technique's excellent spatial resolution. The value of delayed hyperenhancement imaging is for the accurate identification of the infarcted myocardium with resolution that allows determination of the transmural extent of myocardial injury. In addition, nonischemic patterns of myocardial injury such as dilated or hypertrophic cardiomyopathy have been reported in other disease states. Delayed hyperenhancement may have an additional role in guiding the management of or determining the prognosis for diseases such as myocarditis. In this study, the clinical application of delayed hyperenhancement is demonstrated for various cardiac diseases such as myocardial infarction, including right ventricular infarction; microvascular obstruction; and nonischemic cardiomyopathy such as dilated cardiomyopathy and myocarditis.

Contrast Media↗
PubMedDate not supplied

Various findings of cardiac thrombi on MDCT and MRI.

Cardiac thrombus accompanies risk for peripheral embolization, either into the systemic circulation (from the left heart) or into the pulmonary arteries (right heart). In fact, the presence of peripheral emboli should prompt the search for a source within the heart. Echocardiography is the present technique of choice. Also, computed tomography and magnetic resonance imaging may provide additional information. In this article, we will demonstrate various features of cardiac thrombus on computed tomography and magnetic resonance imaging such as mural thrombus after myocardial infarction, thrombus at left atrial appendage in patients with mitral stenosis, thrombus mimicking tumor, organized thrombus containing calcification at left atrium, and compact moderator band mimicking thrombus.

Contrast Media↗