Search PubMed⌕ Search

Biomedical subjects

Woong-Han Kim

Publications and source records attributed to Woong-Han Kim.

At least 19 recordsLinked to original sources

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↗

Hydrothorax in a patient with Denys-Drash syndrome associated with a diaphragmatic defect.

The Wilms tumor suppressor gene, WT1, plays an important role in the development of the urogenital system and the gonads, and clinical syndromes associated with WT1 mutations, such as WAGR syndrome, Denys-Drash syndrome and Frasier syndrome, typically manifest as renal and genitourinary abnormalities. WT1 may also play an important role in the development of the diaphragm, and recently several papers have reported an association between WT1 mutations and diaphragmatic hernias. In addition, WT1 mutations were also detected in some patients with Meacham syndrome, a rare malformation syndrome comprising congenital diaphragmatic hernia, double vagina, sex reversal, and cardiac malformations. Here, we report a case of an infant with typical clinical features of Deny-Drash syndrome and a heterozygous missense mutation, Arg366His, in the WT1 gene, in whom a diaphragm defect was detected after starting peritoneal dialysis. Diaphragmatic defects are rare but may be considered as clinical manifestations of WT1 mutation syndromes. In addition, we suggest that WT1 abnormalities should be suspected in patients with chronic renal failure who develop hydrothorax after peritoneal dialysis, especially in those with genitourinary abnormalities.

Amino Acid Substitution↗

Pulmonary artery banding before the Damus-Kaye-Stansel procedure.

Subaortic stenosis (SAS) in a single ventricle leads to myocardial hypertrophy and compromises Fontan results. Moreover, controversy exists concerning the optimal surgical strategy for relieving SAS. We have applied pulmonary artery banding (PAB) before the Damus-Kaye-Stansel procedure (DKS), and here we analyze factors that influence systemic ventricular compliance. Thirteen patients underwent PAB before DKS. Median PAB duration was 5.5 months (range, 20 days to 17.7 months). Procedures administered concomitantly with DKS were Blalock-Taussig shunt (n = 6), bidirectional cavopulmonary shunt (n = 5), and Fontan operation (n = 2). All survived and were doing well after a median follow-up 2.7 years. Cardiac catheterization before DKS showed that the mean pressure gradient across the systemic ventricular outflow tract and PAB were 20.6 +/- 10.1 and 67.4 +/- 10.2 mmHg, respectively. After DKS, systemic ventricular end diastolic pressure (SVEDP) was significantly correlated with PAB duration (r = 0.65, p = 0.022), but not with PAB or systemic ventricle outflow tract pressure gradients. After DKS, SVEDP decreased or fell to within the range in patients with PAB duration less than 7 months (p < 0.05). Seven patients had a successful Fontan operation, and 6 without risk factors are waiting operation. SVEDP was found to be correlated with PAB duration, and our findings indicate that short-term PAB can be considered a safe option in patients with a single ventricle and SAS.

Discrete Subaortic Stenosis↗

Improving results of the Fontan procedure in patients with heterotaxy syndrome.

BACKGROUND: The Fontan operation in patients with heterotaxy syndrome has been associated with a poor prognosis. We studied whether the outcome of those patients with heterotaxy syndrome improved compared with those who did not have the syndrome after an extracardiac Fontan operation. METHODS: A retrospective review was performed on 185 patients who had undergone an extracardiac Fontan operation between 1996 and 2005. RESULTS: Sixty-two of the patients had heterotaxy syndrome (33.5%). Forty-one had right isomerism and 21 had left isomerism. Heterotaxy syndrome was commonly associated with a morphologic right ventricle (59.7%), a common atrioventricular valve (72.6%), an interrupted inferior vena cava (25.8%), a separate hepatic vein (30.6%), and extracardiac pulmonary venous drainage (16.1%). The hospital mortality rate was higher in the heterotaxy syndrome than nonheterotaxy (4.8% vs 2.4%; p = 0.05). Eight-year survivals were 91.9 +/- 3.2% in the nonheterotaxy group and 89.3 +/- 4.2 % in the heterotaxy group (p = 0.39). At 8 years, freedom from reoperation was 90.2 +/- 3.2% in the nonheterotaxy group and 78.5 +/- 6.2% in the heterotaxy group (p = 0.15). The outcomes (other than those of arrhythmia) were no different between the two groups. The incidences of early and late postoperative arrhythmia were 29.0% and 25.4%, respectively, in heterotaxy patients, and 15.4% and 10.8% in nonheterotaxy patients (p < 0.05). Bradyarrhythmia was found to be more common. During follow-up, atrioventricular valve regurgitation of more than mild was more common in heterotaxy patients (33.9% vs 18.9%; p = 0.05). CONCLUSIONS: Midterm outcomes after an extracardiac Fontan operation in heterotaxy and nonheterotaxy patients are similar, except arrhythmia and atrioventricular valve regurgitation.

Arrhythmias, Cardiac↗

Mid-term follow-up of neoaortic regurgitation after the arterial switch operation for transposition of the great arteries.

OBJECTIVE: The aim of this study was to determine the outcome of the neoaortic valve after the arterial switch operation for transposition of the great arteries. METHODS: A retrospective review of arterial switch operations that were performed during the period from 1991 to 2003 was conducted. We followed patients with echocardiography. When regurgitation of the neoaortic valve was observed we analyzed the risk factors. RESULTS: One hundred and three patients underwent a successful arterial switch operation. Eighty-one males and 22 females participated in the study. Follow-up period was 77+/-42 months. The age and body weight at the time of the arterial switch operation were 1.4+/-2.8 months and 3.8+/-1.0 kg, respectively. Preoperative pulmonary valve regurgitation was found in six patients (two patients had grade I and four patients had grade II). In the postoperative echocardiography, 52 patients demonstrated neoaortic valve regurgitation (26 patients had grade I, 25 patients had grade II, and 1 patient had grade III). At the last follow-up visit, 61 patients demonstrated neoaortic regurgitation (18 patients had grade I, 37 patients had grade II, 5 patients had grade III, and 1 patient had grade IV). Neoaortic valve regurgitation increased progressively with follow-up (p-value<0.01). The size discrepancy between the aorta and the pulmonary artery was correlated with neoaortic valve regurgitation (p-value=0.02). The age and body surface area, relationship of the great arteries, coronary arterial pattern, pulmonary artery banding, use of trap-door technique, myocardial ischemic time, use of total circulatory arrest, and existence of ventricular septal defect were not significant risk factors. CONCLUSIONS: Neoaortic valve regurgitation progressed after the arterial switch operation. The degree of regurgitation was more severe in patients with a size discrepancy between the aorta and the pulmonary artery preoperatively.

Aortic Valve↗

Recovery of acute myocarditis with biventricular assist device in infant.

A 5-month-old boy was admitted to hospital presenting with cardiogenic shock. The echocardiographic examinations revealed a severe ventricular dysfunction. Despite the aggressive medical therapy, his hemodynamic status progressively deteriorated. Mechanical circulatory support was initially provided with extracorporeal membrane oxygenation (ECMO). Because his hemodynamic condition had not improved, the ECMO was removed and a biventricular assist device (BVAD) was instituted. After 10 days, the ventricular function had recovered and the BVAD could be removed. This report describes a successful bridge to recovery using a BVAD in an infant suffering from acute myocarditis.

Acute Disease↗

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↗

Catheter closure of tube graft fenestration in extracardiac Fontan operation.

As the extracardiac Fontan operation evolves, a reliable method for creating and subsequently closing communications between the systemic and pulmonary venous chambers would become useful. We describe a simple and safe technique of fenestration amenable to coil occlusion, which can be carried out in most cardiac catheterization laboratories.

Abnormalities, Multiple↗

Late occurrence of adenosine-sensitive focal junctional tachycardia in complex congenital heart disease.

BACKGROUND: Although supraventricular tachycardia in complex congenital heart disease (CHD) has been reported after surgical repair, its exact electrophysiologic identification has been limited to intraatrial reentrant tachycardia (IART). Moreover, junctional tachycardia (JT) has not previously been described as a cause of late postoperative arrhythmia. METHODS AND RESULTS: Since 1993, a total of 12 patients with congenital heart disease presented with paroxysmal focal JT. The patients with only typical immediate postoperative junctional ectopic tachycardia were excluded. Medical records, standard electrocardiography and Holter monitoring were reviewed. An intracardiac electrophysiologic (EP) study was performed in 11 patients. Ten patients were in post-Fontan status (5.7% of total Fontan survivors). Focal JT occurred more frequently in heterotaxy syndrome among the Fontan survivors (7/52 vs. 3/124; P < 0.05). The commonest anatomy of the atrioventricular (AV) junction was complete AV canal in 8 patients. EP characteristics of focal JT were as follows: (1) various tachycardia mechanisms were identified (increased automaticity or a triggered mechanism in 6/11, and focal reentry in 5/11, including one concealed nodofascicular pathway) (2) ventriculoatrial conduction during tachycardia was either dissociation (7/12) or variable (5/12) (3) All JTs were terminated by adenosine. Class III antiarrhythmic agent was effective in 5/6. His bundle ablation was performed in one Fontan patient, who already had pacemaker because of accompanying intractable IART and sinus node dysfunction. CONCLUSION: Focal JT may be a source of late term supraventricular tachycardia in patients with complex CHD. The tachycardia mechanism was either automatic/triggered or reentrant. In all patients, JT was effectively terminated by adenosine.

Adenosine↗

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↗

Predictive value of intraoperative transesophageal echocardiography in complete atrioventricular septal defect.

BACKGROUND: Intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography have been useful in assessing cardiac function in complete atrioventricular septal defects. However, it has been suggested that a discrepancy exists between intraoperative and postoperative findings, and that intraoperative findings cannot reliably predict long-term results. This study aims to determine whether this discrepancy exists and to assess whether it is possible to predict follow-up results using intraoperative transesophageal echocardiography. METHODS: A retrospective analysis was made in 35 patients who underwent biventricular repair by one surgeon between November 1997 and January 2004. All patients received intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography at 19.1 +/- 18.02 months (range, 7 days to 5 years; median, 15.1 months). RESULTS: In left-sided atrioventricular valve regurgitation, 34.3% (12 of 35) of patients showed discrepancy during follow-up, and 28.6% (10 of 35) showed progression of regurgitation (from grade I to II). In right-sided atrioventricular valve, 11.4% (4 of 35) of patients showed discrepancy, 9.6% (3 of 35) showed progression of regurgitation (from grade I to II). CONCLUSIONS: In complete atrioventricular septal defects, intraoperative transesophageal echocardiography did not show the same findings as that of follow-up transthoracic echocardiography in some cases. However, this discrepancy is not so great as to require reoperation in early to midterm follow-up. Therefore, intraoperative transesophageal echocardiography may be used as tool to predict durability of surgical results and to decrease the incidence of reoperation in complete atrioventricular septal defects.

Adolescent↗

Fontan conversion with arrhythmia surgery.

OBJECTIVE: Hemodynamic abnormalities and refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with Fontan conversion and concomitant arrhythmia surgery. METHODS: Between January 1996 and February 2004, 16 patients underwent Fontan conversion and arrhythmia surgery. Mean age at the initial Fontan operation was 5.1+/-3.5 (range: 2-15) years and mean age at Fontan conversion was 17.0+/-5.8 (range: 6-30). The initial Fontan operations were atriopulmonary connections in 14 patients, extracardiac lateral tunnel in 1, and intracardiac lateral tunnel in 1. The types of arrhythmia included atrial flutter in 10 patients and atrial fibrillation in 3. Fontan conversion operation was performed with intracardiac lateral tunnel in 5 patients and extracardiac conduit in 11. Arrhythmia surgery included isthmus cryoablation in 10 patients and right-sided maze in 3. RESULTS: There has been no mortality. At Fontan conversion operation, 7 patients required permanent pacemaker. All patients have improved to New York Heart Association class I or II. With a mean follow-up of 26.9+/-30.6 (range:1-87) months, 16 patients had sinus rhythm, 2 patients had transient atrial flutter which was well controlled, and 2 patients required permanent pacemaker during follow-up. CONCLUSIONS: Fontan conversion with concomitant arrhythmia surgery and permanent pacemaker placement is safe, improves New York Heart Association functional class, and has a low incidence of recurrent arrhythmias. In most patients, concomitant permanent pacemakers are needed.

Adolescent↗

Twin AV node and induced supraventricular tachycardia in Fontan palliation patients.

INTRODUCTION: The coexistence of two distinct atrioventricular (AV) nodes has been described in congenital heart disease requiring Fontan type palliation. The purpose of this study was to evaluate the occurrence of twin AV node according to anatomical subgroups, and to determine its relation to tachycardia. METHODS: From 2001 to 2003, we performed an electrophysiologic (EP) study upon 52 consecutive patients who had undergone cardiac catheterization after Fontan completion. Atrial pacing was performed at three or more different atrial sites. RESULTS: In 10/52 patients, two different QRS complexes were recorded at different pacing sites, suggesting twin AV node (9/20 in right isomerism, 1/8 discordance AV connections, 0/24 other complex anomalies). AV reciprocating tachycardia (AVRT), presumably involving two AV nodes and a connecting sling, was induced in 6 of 10 patients who had twin AV node (4/6 used posterior AV node as an antegrade limb, 2/6 used an anterior AV node as an antegrade limb). Heterotaxy syndrome (P < 0.001) and complete AV septal defect (P = 0.002) were found to be risk factors for twin AV node. Junctional tachycardia (JT; HR > 150/min) with either VA dissociation (7/9) or second degree VA block (2/9) were induced by pacing or isoproterenol infusion in 9/52 patients. CONCLUSION: JT induction was associated with a twin AV node (P = 0.04), or a history of early postoperative junctional ectopic tachycardia (P = 0.02). A complicated AV node conduction system such as twin AV node was frequent in heterotaxy syndrome. Both AVRT and JT with VA block may be important causes of tachyarrhythmia in this patient group.

Adolescent↗

Extraanatomic ascending-to-descending aortic bypass graft for recurrent, diffuse aortic coarctation.

Surgical correction of recurrent coarctation of the aorta presents a formidable technical challenge. If the lesion is diffuse or has long-segment aortic hypoplasia, it can be more difficult to manage. We present a successful case of repair using an extraanatomic bypass graft from the innominate artery to descending aorta. This technique can be an effective and easy approach for selected cases of complex or reoperative aortic obstruction.

Aorta↗

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↗

Sinus node dysfunction after Fontan modifications--influence of surgical method.

BACKGROUND: Sinus node dysfunction (SND) is reported to be a troublesome complication following various types of Fontan operations. The correlation of post-Fontan SND with surgical methods was evaluated in this study. METHODS: By reviewing the medical records, surface ECGs, and Holter monitoring, the range of heart rate (HR) and the risk of SND at intermediate term after Fontan type operation (follow up: 41.3+/-13.1 months) were analyzed between two age matched groups of patients, consisting of the extracardiac conduit group (EC, n=33) and the lateral tunneling group (LT, n=35). RESULTS: Junctional rhythm was observed in nine out of 35 patients in LT and five out of 33 patients in EC during the follow-up period. Resting HR was faster in EC than that in LT (108+/-15 vs. 82+/-21, P<0.001). Average and maximal HR in Holter monitoring were also faster in EC than those in LT. SND was found in 13 cases (10 in LT, three in EC) during follow-up and one required pacemaker implantation. In the case of situs solitus heart, SND was less frequent in EC than in LT (0/16 vs. 8/26, P=0.01). In the case of heterotaxy syndrome, SND occurred in similar number of cases (3/17 vs. 2/9). The staged approach to Fontan completion did not influence SND. LT repair was the only factor causing sinus node dysfunction according to multivariate logistic regression (P=0.03, OR 5.96). CONCLUSIONS: Lateral tunnel type surgical repair was more likely to lead to the development of sinus node dysfunction than extracardiac conduit operation. In the case of heterotaxy syndrome, surgical method had no significant influence.

Cardiac Surgical Procedures↗