Application of Three-Dimensional Printed Models in Congenital Heart Surgery: Surgeon's Perspective

To treat congenital heart disease, it is important to understand the anatomical structure correctly. Three-dimensional (3D) printed models of the heart effectively demonstrate the structural features of congenital heart disease. Occasionally, the exact characteristics of complex cardiac malformations are difficult to identify on conventional computed tomography, magnetic resonance imaging, and echocardiography, and the use of 3D printed models can help overcome their limitations. Recently, 3D printed models have been used for congenital heart disease education, preoperative simulation, and decision-making processes. In addition, we will pave the way for the development of this technology in the future and discuss various aspects of its use, such as the development of surgical techniques and training of cardiac surgeons.

Application of Three-Dimensional Printed Models in Congenital Heart Surgery: Surgeon's Perspective

To treat congenital heart disease, it is important to understand the anatomical structure correctly. Three-dimensional (3D) printed models of the heart effectively demonstrate the structural features of congenital heart disease. Occasionally, the exact characteristics of complex cardiac malformations are difficult to identify on conventional computed tomography, magnetic resonance imaging, and echocardiography, and the use of 3D printed models can help overcome their limitations. Recently, 3D printed models have been used for congenital heart disease education, preoperative simulation, and decision-making processes. In addition, we will pave the way for the development of this technology in the future and discuss various aspects of its use, such as the development of surgical techniques and training of cardiac surgeons.

Staged Repair of Truncus Arteriosus Associated with Complete Atrioventricular Septal Defect

We report a case of successful repair of truncus arteriosus (TA) associated with complete atrioventricular septal defect (c-AVSD) using a staged approach. TA associated with c-AVSD is a very rare congenital cardiac anomaly. No report of successful staged repair in South Korea has yet been published. We performed bilateral pulmonary artery banding when the patient was 33 days old, and total correction using an extracardiac conduit was performed at the age of 18 months. The patient recovered uneventfully and is doing well.

Changes of the Structural and Biomechanical Properties of the Bovine Pericardium after the Removal of alpha-Gal Epitopes by Decellularization and alpha-Galactosidase Treatment

BACKGROUND: Bovine pericardium is one of the most widely used materials in bioprosthetic heart valves. Immunologic responses have been implicated as potential causes of limited durability of xenogenic valves. This study aimed to determine the effectiveness of decellularization and alpha-galactosidase (alpha-gal) to remove major xenoreactive antigens from xenogenic tissues. MATERIALS AND METHODS: Recombinant Bacteroides thetaiotaomicron (B. thetaiotaomicron) alpha-gal or decellularization, or both were used to remove alpha-gal from bovine pericardium. It was confirmed by alpha-gal-bovine serum albumin-based enzyme-linked immunosorbent assay (ELISA), high-performance anion exchange chromatography, flow cytometry, 3,3'-diaminobenzidine-staining, and lectin-based ELISA. The mechanical properties of bovine pericardium after decellularization or alpha-gal treatment were investigated by tests of tensile-strength, permeability, and compliance. Collagen fiber rearrangement was also evaluated by a 20,000x transmission electron microscope (TEM). RESULTS: Recombinant B. thetaiotaomicron alpha-gal could effectively remove alpha-gal from bovine pericardium B. thetaiotaomicron (0.1 U/mL, pH 7.2) while recombinant human alpha-gal removed it recombinant human alpha-gal (10 U/mL, pH 5.0). There was no difference in the mechanical properties of fresh and recombinant alpha-gal-treated bovine pericardium. Furthermore, the TEM findings demonstrated that recombinant alpha-gal made no difference in the arrangement of collagen fiber bundles with decellularization. CONCLUSION: Recombinant B. thetaiotaomicron alpha-gal effectively removed alpha-gal from bovine pericardium with a small amount under physiological conditions compared to human recombinant alpha-gal, which may alleviate the harmful xenoreactive immunologic responses of alpha-gal. Recombinant alpha-gal treatment had no adverse effects on the mechanical properties of bovine pericardium.

Arterial Switch Operation in Patients with Intramural Coronary Artery: Early and Mid-term Results

BACKGROUND: The intramural coronary artery has been known as a risk factor for early death after an arterial switch operation (ASO). We reviewed the morphological characteristics and evaluated the early and mid-term results of ASO for patients with an intramural coronary artery. MATERIALS AND METHODS: From March 1994 to September 15th 2010, 158 patients underwent ASO at Dong-A and Pusan National University Hospitals for repair of transposition of the great arteries and double outlet right ventricle. Among these patients, 14 patients (8.9%) had an intramural coronary artery. Mean age at operation was 13.4+/-10.2 days (4 to 39 days) and mean body weight was 3.48+/-0.33 kg (2.88 to 3.88 kg). All patients except one were male. Eight patients had TGA/IVS and 4 patients had an aortic arch anomaly. Two patients (14.3%) had side-by-side great artery relation, of whom one had an intramural right coronary artery and the other had an intramural left anterior descending coronary artery. Twelve patients had anterior-posterior relation, all of whom had an intramural left coronary artery (LCA). The aortocoronary flap technique was used in coronary transfer in 8 patients, of whom one patient required a switch to the individual coronary button technique 2 days after operation because of myocardial ischemia. An individual coronary button implantation technique was adopted in 6, of whom 2 patients required left subclavian artery free graft to LCA during the same operation due to LCA injury during coronary button mobilization and LCA torsion. RESULTS: There was 1 operative death (7.1%), which occurred in the first patient in our series. This patient underwent an aortocoronary flap procedure for coronary transfer combining aortic arch repair. Overall operative mortality for 144 patients without an intramural coronary artery was 13.2% (19/144). There was no statistical difference in operative mortality between the patients with and without an intramural coronary artery (p>0.1). There was no late death. The mean follow-up duration was 52.1+/-43.0 months (0.5 to 132 months). One patient who had a subclavian artery free graft required LCA stenting 6.5 years after surgery for LCA anastomotic site stenosis. No other surviving patient needed any intervention for coronary problems. All patients had normal ventricular function at latest echocardiography and were in NYHA class 1. CONCLUSION: The arterial switch operation in Transposition of Great Arteries or Double Outlet Right Ventricle patients with intramural coronary can be performed with low mortality; however, there is a high incidence of intraoperative or postoperative coronary problems, which can be managed with conversion to the individual coronary button technique and a bypass procedure using a left subclavian free graft. Both aortocoronary flap and individual coronary button implantation techniques for coronary transfer have excellent mid-term results.

Analysis of Neonatal Gastrointestinal Diseases in a Neonatal Intensive Care Unit for 3 Years Neonatal GI Diseases in a NICU for 3 Years

PURPOSE: To report our experience of gastrointestinal operations performed in neonates including low birth weight infants and to evaluate their clinical characteristics. METHODS: We retrospectively reviewed the medical records of patients who underwent neonatal gastrointestinal surgery or had necrotizing enterocolitis (NEC) or inguinal hernia from January 2008 to December 2010 at Pusan National University School of Medicine. RESULTS: The main disease was anorectal malformation and male patients were dominant. Twenty four patients (19.2%) had one or more associated anomalies including hydronephrosis and congenital heart disease. Eighteen patients (43.9%) of anorectal malformation had other anomalies. Seventy six percent of NEC cases were very low birth weight infants. Concerning mean days of full enteral feeding after operation, NEC patients needed 30.8 days, which was the longest period. Overall mortality of operation (except NEC and inguinal hernia operation) was 1.6%. The mortality of NEC with surgical treatment was 18.8%. The direct bilirubin in the operation group was significant higher than in the non-operation group in NEC patients. CONCLUSION: The morbidity and mortality after neonatal gastrointestinal surgery were excellent. The direct bilirubin in the operation group was significant higher than in the non-operation group in NEC.

Outcome of Staged Repair of Tetralogy of Fallot with Pulmonary Atresia and a Ductus-dependent Pulmonary Circulation: Should Primary Repair Be Considered?

BACKGROUND: The tetralogy of Fallot (TOF) with pulmonary atresia (PA) and a ductus-dependent pulmonary circulation (no major aorto-pulmonary collateral arteries (MAPCAs)) has been treated with staged repair or primary repair depending on the preference of surgeons or institutions. We evaluated the 19-year outcome of staged repair for this anomaly to find out whether our surgical strategy should be changed. MATERIALS AND METHODS: Forty-four patients with TOF/PA with patent ductus arteriosus (PDA) who underwent staged repair from June 1991 to October 2010 were included in this retrospective study. The patients with MAPCAs were excluded. The average age at the first palliative shunt surgery was 40.8+/-67.5 days (range: 0~332 days). Thirty-one patients (31/44, 70%) were neonates. The average weight was 3.5+/-1.6 kg (range: 1.6~8.7 kg). A modified Blalock-Taussig (BT) shunt was performed in 38 patients, classic BT shunt in 4 patients, and central shunt in 2 patients. Six patients required concomitant procedures: pulmonary artery angioplasty was performed in 4 patients, pulmonary artery reconstruction in one patient, and re-implantation of the left pulmonary artery to the main pulmonary artery in one patient. Four patients required a second shunt operation before the definitive repair was performed. Thirty-three patients underwent definitive repair at 24.2+/-13.3 months (range: 7.3~68 months) after the first palliative operation. The average age at the time of definitive repair was 25.4+/-13.5 months (range: 7.6~68.6 months) and their average weight was 11.0+/-2.1 kg. For definitive repair, 3 types of right ventricular outflow procedures were used: extra-cardiac conduit was performed in 30 patients, trans-annular patch in 2 patients, and REV operation in 1 patient. One patient was lost to follow-up after hospital discharge. The mean follow-up duration for the rest of the patients was 72+/-37 months (range: 4~160 months). RESULTS: Ten patients (10/44, 22.7%) died before the definitive repair was performed. Four of them died during hospitalization after the shunt operation. Six deaths were thought to be shunt-related. The average time of shunt-related deaths after shunt procedures was 8.7 months (range: 2 days~25.3 months). There was no operative mortality after the definitive repair, but one patient died from dilated cardiomyopathy caused by myocarditis 8 years and 3 months after the definitive repair. Five-year and 10-year survival rates after the first palliative operation were 76.8% and 69.1%, respectively. CONCLUSION: There was a high overall mortality rate in staged repair for the patients with TOF/PA with PDA. Majority of deaths occurred before the definitive repair was performed. Therefore, primary repair or early second stage definitive repair should be considered to enhance the survival rate for patients with TOF/PA with PDA.

Comparison of Different Methods of Aortic Valve Conduit Xenograft Preservation in an Animal Experiment Model; Fresh Cryopreservation versus Acellularized Cryopreservation / 대한흉부외과학회지

BACKGROUND: The commercially used vascular xenografts have some problems such as calcification, fibrosis and tissue degeneration that are associated with inflammatory and immunologic reactions. We compared two methods of xenograft preservation (fresh cryopreservation versus acellularized cryopreservation) of goat aorta. MATERIAL AND METHOD: Aortic valved xenografts were harvested from adult pigs, and these were preserved using fresh cryopreservation (FC group, n=4) or acellularized crypreservation (AC group, n=4). These xenografts were implanted into adult goats. There were 2 short-term survivors (less than 100 days) and 2 long-term survivors in each group. These xenografts were explanted and they underwent microscopic examination. RESULT: The goats survived 31, 40, 107 and 411 days in the FC group and the other goats survived 5, 40, 363 and 636 days in the AC group. All the short-term survivors in each group expired because of rupture at the proximal anastomosis site. Marked neutrophil infiltration was observed in the FC group FC and lymphocytes were observed in the AC group. There were no differences in the occurrence of calcification, fibrosis and thrombosis among the groups. CONCLUSION: Some goats survived more than 100 days after the xenograft implantation irrespective of the methods of preservation. Because severe tissue degeneration developed in both groups, we think these methods are not appropriate for xenograft preservation of aorta. It was worth a preliminary trial for improving the preservation method or to modify the processing of xenografts.

Outcome of the Modified Norwood Procedure: 7 Years of Experience from a Single Institution / 대한흉부외과학회지

BACKGROUND: We assessed the early and mid-term results of the modified Norwood procedure for first-stage palliation of hypoplastic left heart syndrome (HLHS) and its variants to identify the risk factors for hospital mortality. MATERIAL AND METHOD: Between March, 2003, and December, 2009, 23 patients (18 males and 5 females) with HLHS or variants underwent the modified Norwood procedure. The age at operation ranged from 3 to 60 days (mean, 11.7+/-13.2 days) and weight at operation ranged from 2.2 to 4.8 kg (mean, 3.17+/-0.52 kg). We used a modified technique that spared the anterior wall of the main pulmonary artery in 20 patients. The sources of pulmonary blood flow were RV-PA conduit in 15 patients (group I) and RMBTS in 8 (group II). Follow-up was completed in 19 patients (19/20, 95%) in our hospital (mean 26.0+/-22.8 months). RESULT: Early death occurred in 3 patients (3/23, 13%), of whom 2 had TAPVC. Fourteen patients underwent subsequent bidirectional cavopulmonary connection (BCPC, stage 2) and seven underwent the Fontan operation (stage 3). Three patients died between stages, 2 before stage 2 and one before stage 3. The estimated 1-year and 5-year survival rates were 78% and 69%, respectively. On multivariate regression analysis, aberrant right subclavian artery (RSCA) and associated total anomalous pulmonary venous connection (TAPVC) were risk factors for hospital mortality after stage 1 Norwood procedure. CONCLUSION: HLHS and its variants can be palliated by the modified Norwood procedure with low operative mortality. Total anomalous pulmonary venous connection adversely affects the survival after a stage 1 Norwood procedure, and interstage mortality rates need to be improved.

Staged Repair of Esophageal Atresia with Tracheoesophageal Fistula in a Very Low-birth-weight Infant: A case report / 대한흉부외과학회지

There are still some controversies in treatment strategy for the very low-birth-weight baby with esophageal atresia even though the result of primary repair has been improving. We report a successful end to end anastomosis with staged approach in one of twin weighing 1,270 g at birth.

Outcomes of the arterial switch operation in complete transposition of the great arteries / 소아과

PURPOSE: The arterial switch operation (ASO) has become the preferred procedure for the surgical management of transposition of the great arteries (TGA). We conducted a retrospective evaluation of our experience in 30 patients seen from January 2003 to July 2008, in order to determine outcomes and related risk factors after the arterial switch operation. METHODS: Patients charts, surgical reports, and echocardiograms were retrospectively reviewed. And they were analyzed in 2 different groups: complex (n=16) versus simple TGAs (n=14). Complex TGAs are TGAs with VSD or the Taussig-Bing anomaly with or without aortic arch anomalies. Simple TGAs are defined as TGAs with intact ventricular septum having no such anomalies. Median follow-up time was 44 months (3-63 months). RESULTS: Hospital mortality was 0%. However, follow-up echocardiographies revealed potential complications, including stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, and right or left ventricular outflow tract obstructions. Great arterial relationship (side-by-side), association of aortic arch anomalies, and the existence of the Taussig-Bing anomaly were assessed as significant risk factors of neo-aortic and/or neo-pulmonary valvar regurgitation in this series. On the other hand, right or left ventricular outflow tract obstructions were more frequently found in patients demonstrating VSD, side-by-side positioned great arteries, or associated coronary anomalies. CONCLUSION: The ASO is the procedure of choice in the treatment of TGA. However, special attention and follow-ups are needed to detect residual problems like the stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, as well as ventricular outflow tract obstructions.

Bivalvation Valvuloplasty for Common Atrioventricular Valve Regurgitation in Functional Single Ventricle; Early and Mid-term Results / 대한흉부외과학회지

BACKGROUND: Atrioventricular valve regurgitation in pediatric patients with a functional single ventricles (FSV) - has been known as one of the important risk factors for death and unfavorable long-term results after a Fontan operation. We evaluated early and mid-term results of bivalvation valvuloplasty in FSV patients. MATERIAL AND METHOD: We retrospectively evaluated 11 patients with a functional single ventricle who underwent bivalvation valvuloplasty between 1999 and 2007. The degree of common atrioventricular valve regurgitation (CAVVR) was determined by color Doppler echocardiography (regurgitation grade scoring, trivial; 1, mild; 2, moderate; 3, severe; 4). Mean age at valve surgery was 6.9+/-7.0 months (median 4 months, 24 days~21 months) and mean body weight was 6.2+/-2.8 kg (3.1~11.3 kg). Nine patients had isomerism heart and two of them had TAPVC. The concomitant procedures were performed in all but one patient. Additional commissural closure was performed in 3 patients and commissural annuloplasty in another 3 patients. RESULT: There was one hospital death after surgery. A 32-day old patient who had been preoperatively dependent on a ventilator died of air way and lung problems 4.3 months after pulmonary artery banding and bivalvation valvuloplasty. Mean follow-up duration was 40 months (4.3~114 months). Mean preoperative CAVVR score was 3.3+/-0.6, which decreased to 1.9+/-0.7 postoperatively (p<0.0001). This residual regurgitation slightly increased to 2.2+/-0.4 (no statistical significance) after a mean follow-up of 14.3 months. Six patients (60%) required re-operations for residual regurgitation at a subsequent bidirectional cavopulmonary shunt or Fontan operation. One patient with Ebsteinoid malformation of the right sided atrioventricular valve required valve replacement due to stenoinsufficiency. Another patient required edge-to-edge repair at the right sided AV valve (between the right mural leaflet and the bridging leaflets). The remaining 4 patients required additional suture placements between bridging leaflets with or without commissural annuloplasty. All survivor had trivial or mild CAVVR at the latest follow-up. CONCLUSION: Bivalvation valvuloplasty for CAVVR in FSV patients is an effective and safe procedure. However, significant numbers of the patients have small residual regurgitation and require additional valve procedures at subsequent operations. Long-term observations to monitor progression of the CAVVR is mandatory.

Does Bilateral Pedicle Internal Thoracic Artery Harvest Increase the Risk of Mediastinitis?

PURPOSE: Bilateral in situ internal thoracic artery (ITA) bypassing may result in excellent myocardial revascularization without increasing the risk of deep sternal wound infection. Although there have been concerns with the use of pedicled bilateral ITA, the risk of infection may not be greater than the use of skeletonized ITA. MATERIALS AND METHODS: The present study was retrospectively undertaken to determine if pedicled BITA grafts are associated with a higher risk of sternal wound complications. A total of 207 patients who underwent bilateral ITA bypasses with or without existing diabetes mellitus, and 162 patients of those received bilateral pedicled ITA and 98 patients received unilateral ITA bypass grafts. RESULTS: No sternal wound complications were noted in either the bilateral ITA or unilateral left ITA groups. CONCLUSION: Bilateral pedicled ITA harvesting was not associated with a greater incidence of infectious sternal complications compared to patients receiving unilateral ITA bypass grafts.

Study on an Effective Decellularization Technique for Cardiac Valve, Arterial Wall and Pericardium Xenographs: Optimization of Decellularization / 대한흉부외과학회지

BACKGROUND: We attempted to reproduce a previously reported method that is known to be effective for decellularization, and we sought to find the optimal condition for decellularization by introducing some modificationsto this method. MATERIAL AND METHOD: Porcine semilunar valves, arterial walls and pericardium were processed for decellularization with using a variety of combinations and concentrations of decellularizing agents under different conditions of temperature, osmolarity and incubation time. The degree of decellularization and the preservation of the extracellular matrix wereevaluated by staining with hematoxylin and eosin and with alpha-Gal and DAPI in some of the decellularized tissues. RESULT: Decellularization was achieved in the specimens that were treated with sodium deoxycholate, sodium dodesyl sulfate, Triton X-100 and sodium dodesyl sulfate with Triton X-100 as single-step methods, and this was also achieved in the specimens that were treated with hypotonic solution --> Triton X-100 --> sodium dodesyl sulfate, sodium deoxycholate --> hypotonic solution --> sodium dodesyl sulfate, and hypotonic solution sodium dodesyl sulfate as multi-step methods. CONCLUSION: Considering the number and the amount of the chemicals that were used, the incubation time and the degree of damage to the extracellular matrix, a single-step method with sodium dodesyl sulfate and Triton X-100 and a multi-step method with hypotonic solution followed by sodium dodesyl sulfate were both relatively optimal methods for decellularization in this study.

A Study on an Effective Decellularization Technique for a Xenograft Cardiac Valve: the Effect of Osmotic Treatment with Hypotonic Solution / 대한흉부외과학회지

BACKGROUND: Cellular remnants in the bioprosthetic heart valve are known to be related to a host's immunologic response and they can form the nidus for calcification. The extracellular matrix of the decellularized valve tissue can also be used as a biological scaffold for cell attachment, endothelialization and tissue reconstitution. Thus, decellularization is the most important part in making a bioprosthetic valve and biological scaffold. Many protocols and agents have been suggested for decellularization, yet there have been few reports about the effect of a treatment with hypotonic solution prior to chemical or enzymatic treatment. This study investigated the effect of a treatment with hypotonic solution and the appropriate environments such as temperature, the treatment duration and the concentration of sodium dodecylsulfate (SDS) for achieving proper decellularization. MATERIAL AND METHOD: Porcine aortic valves were decellularized with sodium dodecylsulfate at various concentrations (0.25%, 0.5%), time durations (6, 12, 24 hours) and temperatures (4degrees C, 20degrees C)(Group B). Same the number of porcine aortic valves (group A) was treated with hypotonic solution prior to SDS treatment at the same conditions. The duration of exposure to the hypotonic solution was 4, 7 and 14 hours and the temperature was 4degrees C and 20degrees C, respectively. The degree of decellularization was analyzed by performing hematoxylin and eosin staining. RESULT: There were no differences in the degree of decellularization between the two concentrations (0.25% 0.5%) of SDS. Twenty four hours treatment with SDS revealed the best decellularization effect for both groups A and B at the temperature of 4degrees C, but there was no differences between the groups at 20degrees C. Treatment with hypotonic solution (group A) showed a better decellularization effect at all the matched conditions. Fourteen hours treatment at 4degrees C with hypotonic solution prior to SDS treatment revealed the best decellularization effect. The treatment with hypotonic solution at 20degrees C revealed a good decellularization effect, but this showed significant extracellular matrix destruction. CONCLUSION: The exposure of porcine heart valves to hypotonic solution prior to SDS treatment is highly effective for achieving decellularization. Osmotic treatment with hypotonic solution should be considered for achieving decellularization of porcine aortic valves. Further study should be carried out to see whether the treatment with hypotonic solution could reduce the exposure duration and concentration of chemical detergents, and also to evaluate how the structure of the extracellular matrix of the porcine valve is affected by the exposure to hypotonic solution.

One Stage Repair of Berry Syndrome in a Neonate Using an Autologous Arterial Flap / 대한흉부외과학회지

Berry syndrome (a distal aortopulmonary window and a right pulmonary artery originating from the ascending aorta, an intact ventricular septum, a patent ductus arteriosus and an interrupted aortic arch) is a rare complex congenital cardiac malformation. We describe a case of one stage repair with using an autologous arterial flap in a 19-day-old neonate who was suffering with this malformation, and we report on the development of postoperative right pulmonary artery stenosis and its successful management with performing multiple balloon angioplasties.

Histidine-tryptophan-ketoglutarate Versus Blood Cardioplegic Solutions: A Prospective, Myocardial Ultrastructural Study / 대한흉부외과학회지

BACKGROUND: We performed a prospective clinical study to evaluate the ultrastructural integrity of the myocardium after using Histidine-Tryptophan-Ketoglutarate (HTK) solution in comparison with blood cardioplegic solution during congenital heart surgery. MATERIAL AND METHOD: Twenty two patients with acyanotic heart disease, who were scheduled for elective open heart surgery, were randomized into two groups. The HTK Group (n=11) received HTK cardioplegic solution; the blood group (n=11) received conventional blood cardioplegic solution during surgery. The preoperative diagnoses included ventricular septal defect (n=9) and atrial septal defect (n=2) in each group. A small biopsy specimen was taken from the right ventricle's myocardium, and this was processed for ultrastructural examination at the end of 30 minutes of reperfusion. Semiquantitative electron microscopy was carried out "blindly" in 4 areas per specimen and in 5 test fields per area by 'random systematic sampling' and 'point and intersection counting'. The morphology of the mitochondrial membrane and cristae were then scored. The interstitial edema of the myocardium was also graded. RESULT: The semiquantitative score of the mitochondrial morphology was 19.65+/-4.75 in the blood group and 25.25+/-5.85 in the HTK group (p=0.03). 6 patients (54.5%) in the blood group and 3 patients (27.3%) in the HTK group were grade 3 or more for the interstitial edema of the myocardium. CONCLUSION: The ultrastructural integrity was preserved even better with HTK solution than with conventional blood cardioplegic solution.

Replacement of Obstructed Extracardiac Conduits with Autologous Tissue Reconstructions (Peel operation); Early and Midterm Results / 대한흉부외과학회지

BACKGROUND: Reoperation is usually required for a right ventricle to pulmonary artery conduit obstruction caused by valve degeneration, conduit peel formation or somatic growth of the patient. An autologous tissue reconstruction (peel operation), where a prosthetic roof is placed over the fibrotic tissue bed of the explanted conduit, has been used to manage conduit obstructions at our institute since May 2002. Herein, the early and midterm results are evaluated. MATERIAL AND METHOD: Between May 2002 and July 2006, 9 patients underwent obstructed extracardiac conduit replacement with an autologous tissue reconstruction, at a mean of 5.1 years after a Rastelli operation. The mean age at reoperation was 7.5+/-2.4 years, ranging from 2.9 to 10.1 years. The diagnoses included 6 pulmonary atresia with VSD, 2 truncus arteriosus and 1 transposition of the great arteries. The preoperative mean systolic gradient was 88.3+/-22.2 mmHg, ranging from 58 to 125 mmHg. The explanted conduits were all Polystan valved pulmonary conduit (Polystan, Denmark). A bioprosthetic valve was inserted in 8 patients, and a monocusp ventricular outflow patch (MVOP) was used in 1 patient. The anterior wall was constructed with a Gore-Tex patch (n=7), MVOP (n=1) and bovine pericardium (n=1). Pulmonary artery angioplasty was required in 5 patients and anterior aortopexy in 2. The mean cardiopulmonary bypass time was 154 minutes, ranging from 133 to 181 minutes; an aortic crossclamp was not performed in all patients. The mean follow-up duration was 20 months, ranging from 1 to 51 months. All patients were evaluated for their right ventricular outflow pathway using a 3-D CT scan. RESULT: There was no operative mortality or late death. The mean pressure gradient, assessed by echocardiography through the right ventricular outflow tract, was 20.4 mmHg, ranging from 0 to 29.6 mmHg, at discharge and 26 mmHg, ranging from 13 to 36 mmHg, at the latest follow-up (n=7, follow-up duration >1 year). There were no pseudoaneurysms, strictures or thrombotic occlusions. CONCLUSION: A peel operation was concluded to be a safe and effective re-operative option for an obstructed extracardiac conduit following a Rastelli operation.

Can Peritoneal Dialysis Remove Endothelin-1 after Cardiopulmonary Bypass for Repair of Congenital Heart Disease? / 대한흉부외과학회지

BACKGROUND: Lung injury that follows bypass has been well described. It is manifested as reduced oxygenation and lung compliance and, most importantly, increased pulmonary vascular resistance reactivity; this is a known cause of morbidity and mortality after repair of congenital heart disease. Injury to the pulmonary vascular endothelium, and its associated alterations of endothelin-1, is considered to be a major factor of bypass-induced lung injury. Removing endothelin-1 after bypass may attenuate this response. This study measured the concentration of serum and peritoneal effluent endothelin-1 after performing bypass to determine if endothelin-1 can be removed via peritoneal dialysis. MATERIAL AND METHOD: From March 2005 to March 2006, 18 patients were enrolled in this study. Peritoneal catheters were placed at the end of surgery. Serum samples were obtained before and after bypass, and peritoneal effluents were obtained after bypass. Endothelin-1 was measured by enzyme linked immunosorbent assay (ELISA). RESULT: In the patients with a severe increase of the pulmonary artery pressure or flow, the mean preoperative plasma endothelin-1 concentration was significantly higher than that in the patients who were without an increase of their pulmonary artery pressure or flow (4.2 vs 1.8 pg/mL, respectively, p<0.001). The mean concentration of plasma endothelin-1 increased from a preoperative value of 3.61+/-2.17 to 5.33+/-3.72 pg/ml immediately after bypass. After peritoneal dialysis, the mean plasma endothelin-1 concentration started to decrease. Its concentration at 18 hours after bypass was significantly lower than the value obtained immediately after bypass (p=0.036). CONCLUSION: Our data showed that the plasma endothelin-1 concentration became persistently decreased after starting peritoneal dialysis, and this suggests that peritoneal dialysis can remove the circulating plasma endothelin-1.

Midterm Result of Starnes Operation: A case report / 대한흉부외과학회지

We report here on the midterm results after a Starnes operation for a severely symptomatic neonate with Ebstein's anomaly. A one-day-old baby presented with cyanosis and severe cardiomegaly. We performed patch closure of the tricuspid valve with a central shunt after failure of tricuspid valve repair with vertical plication of the atrialized ventricle at her age of 19 days. The coronary sinus was drained into the right ventricle. She underwent bidirectional cavopulmonary shunt and extracardiac conduit Fontan operation at her age of 16 and 30 months, respectively. She is now 56 months old and is doing very well. The recent follow-up study revealed that she was in normal sinus rhythm and had a normal sized left ventricle with good function and the small right ventricle without thrombus formation.