Growth Pattern of the Neo-Aorta after Arterial Switch Operation during Childhood

Background and Objectives@#Neo-aortic root dilatation (ARD) and annular dilatation (AAD) tend to develop after arterial switch operation (ASO). However, the trend of neo-aortic growth has not been well established. This paper aims to identify this trend, its associated factors, and predictors of neo-aortic dilatation after ASO. @*Methods@#We analyzed the growth trend of the neo-aortic root, annulus, and sinotubular junction (STJ) z-scores using random coefficients model and the risk factors affecting neoaortic dilatation in 163 patients who underwent ASO from 2006 to 2015. @*Results@#Among 163 patients, 41 had a ventricular septal defect, and 11 had Taussig-Bing (TB) anomaly. The median follow-up duration was 6.61 years. The increased in the neo-aortic root z-score was different between the trapdoor and non-trapdoor coronary artery transfer techniques (0.149/year, p<0.001 vs. 0.311/year, p<0.001). Moreover, the neo-aortic annulus and STJ z-score significantly increased over time after ASO (0.067/year, p<0.001; 0.309/ year, p<0.001). Pulmonary artery banding (PAB) was rather a negative affecting factor. The probabilities of freedom from ARD, AAD, and neo-aortic STJ dilatation at 10 years after ASO were 33.4%, 53.9%, and 65.4%. Neo- aortic regurgitation within 1 year was the predictor of ARD, AAD, and neo-aortic STJ dilatation. TB anomaly, PAB, and native pulmonary sinus z-score were other predictors for ARD. @*Conclusion@#The growth of neo-aortic root, annulus, and STJ after ASO was greater than somatic growth during childhood. The coronary artery transfer technique affected the growth pattern of the neo-aortic root.

Growth Pattern of the Neo-Aorta after Arterial Switch Operation during Childhood

Background and Objectives@#Neo-aortic root dilatation (ARD) and annular dilatation (AAD) tend to develop after arterial switch operation (ASO). However, the trend of neo-aortic growth has not been well established. This paper aims to identify this trend, its associated factors, and predictors of neo-aortic dilatation after ASO. @*Methods@#We analyzed the growth trend of the neo-aortic root, annulus, and sinotubular junction (STJ) z-scores using random coefficients model and the risk factors affecting neoaortic dilatation in 163 patients who underwent ASO from 2006 to 2015. @*Results@#Among 163 patients, 41 had a ventricular septal defect, and 11 had Taussig-Bing (TB) anomaly. The median follow-up duration was 6.61 years. The increased in the neo-aortic root z-score was different between the trapdoor and non-trapdoor coronary artery transfer techniques (0.149/year, p<0.001 vs. 0.311/year, p<0.001). Moreover, the neo-aortic annulus and STJ z-score significantly increased over time after ASO (0.067/year, p<0.001; 0.309/ year, p<0.001). Pulmonary artery banding (PAB) was rather a negative affecting factor. The probabilities of freedom from ARD, AAD, and neo-aortic STJ dilatation at 10 years after ASO were 33.4%, 53.9%, and 65.4%. Neo- aortic regurgitation within 1 year was the predictor of ARD, AAD, and neo-aortic STJ dilatation. TB anomaly, PAB, and native pulmonary sinus z-score were other predictors for ARD. @*Conclusion@#The growth of neo-aortic root, annulus, and STJ after ASO was greater than somatic growth during childhood. The coronary artery transfer technique affected the growth pattern of the neo-aortic root.

Heart Transplantation in Patients with Superior Vena Cava to Pulmonary Artery Anastomosis: A Single-Institution Experience

BACKGROUND: Heart transplantation (HTx) can be a life-saving procedure for patients in whom single ventricle palliation or one-and-a-half (1½) ventricle repair has failed. However, the presence of a previous bidirectional cavopulmonary shunt (BCS) necessitates extensive pulmonary artery angioplasty, which may lead to worse outcomes. We sought to assess the post-HTx outcomes in patients with a previous BCS, and to assess the technical feasibility of leaving the BCS in place during HTx. METHODS: From 1992 to 2017, 11 HTx were performed in patients failing from Fontan (n=7), BCS (n=3), or 1½ ventricle (n=1) physiology at Asan Medical Center. The median age at HTx was 12.0 years (range, 3–24 years). Three patients (27.3%) underwent HTx without taking down the previous BCS. RESULTS: No early mortality was observed. One patient died of acute rejection 3.5 years after HTx. The overall survival rate was 91% at 2 years. In the 3 patients without BCS take-down, the median anastomosis time was 65 minutes (range, 54–68 minutes), which was shorter than in the patients with BCS take-down (93 minutes; range, 62–128 minutes), while the postoperative central venous pressure (CVP) was comparable to the preoperative CVP. CONCLUSION: Transplantation can be successfully performed in patients with end-stage congenital heart disease after single ventricle palliation or 1½ ventricle repair. Leaving the BCS in place during HTx may simplify the operative procedure without causing significant adverse outcomes.

Surgical Reconstruction for High-Output Chylothorax Associated with Thrombo-Occlusion of Superior Vena Cava and Left Innominate vein in a Neonate

We report a case of high-output chylothorax associated with thrombo-occlusion of the superior vena cava (SVC) and left innominate vein (LIV) following an arterial switch operation in a neonate. The chylothorax was resolved by 3 weeks after surgical reconstruction of the SVC and LIV using fresh autologous pericardium. We confirmed the patency of the SVC and LIV with a 1-year follow-up computed tomographic scan at our outpatient clinic.

Extracorporeal Membrane Oxygenation Cannula Malposition in the Azygos Vein in a Neonate with Right-Sided Congenital Diaphragmatic Hernia / 대한구급학회지

Malposition of the extracorporeal membrane oxygenation (ECMO) venous cannula in the azygos vein is not frequently reported. We hereby present such a case, which occurred in a neonate with right-sided congenital diaphragmatic hernia. Despite ECMO application, neither adequate flow nor sufficient oxygenation was achieved. On the cross-table lateral chest radiograph, the cannula tip was identified posterior to the heart silhouette, which implied malposition of the cannula in the azygos vein. After repositioning the cannula, the target flow and oxygenation were successfully achieved. When sufficient venous flow is not achieved, as in our case, clinicians should be alerted so they can identify the cannula tip location on lateral chest radiograph and confirm whether malposition in the azygos vein is the cause of the ineffective ECMO.

Extracorporeal Membrane Oxygenation Cannula Malposition in the Azygos Vein in a Neonate with Right-Sided Congenital Diaphragmatic Hernia / 대한중환자의학회지

Malposition of the extracorporeal membrane oxygenation (ECMO) venous cannula in the azygos vein is not frequently reported. We hereby present such a case, which occurred in a neonate with right-sided congenital diaphragmatic hernia. Despite ECMO application, neither adequate flow nor sufficient oxygenation was achieved. On the cross-table lateral chest radiograph, the cannula tip was identified posterior to the heart silhouette, which implied malposition of the cannula in the azygos vein. After repositioning the cannula, the target flow and oxygenation were successfully achieved. When sufficient venous flow is not achieved, as in our case, clinicians should be alerted so they can identify the cannula tip location on lateral chest radiograph and confirm whether malposition in the azygos vein is the cause of the ineffective ECMO.

Pulmonary Atresia with Ventricular Septal Defect and Major Aortopulmonary Collaterals Associated with Left Pulmonary Artery Interruption

A multistage plan and multidisciplinary approach are the keys to successful repair in patients with pulmonary atresia (PA) with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCAs). In this article, we present a multidisciplinary approach adopted to treat a patient with PA with VSD and MAPCAs associated with left pulmonary artery interruption.

Living-donor Sequential ABO-incompatible Kidney Transplantation after Liver Transplantation in a Patient with Alcoholic Liver Cirrhosis and End-stage Renal Disease / 대한이식학회지

A 47-year-old man developed chronic alcoholic liver cirrhosis and end-stage renal disease. He underwent blood-type-compatible liver transplantation with a graft from his daughter. After 8 months, sequential ABO-incompatible (ABOi) kidney transplantation was performed, with his brother as the donor (A to O). The patient had anti-A antibody titers (1:256). We performed pretransplant desensitization, including administration of rituximab, mycophenolate mofetil, tacrolimus, and prednisolone 2 weeks before the scheduled transplantation, and plasmaphresis (PP) and administered an intravenous immunoglobulin injection. The patient underwent PP before kidney transplantation until the anti-A antibody titer was <1:8. The patient achieved normal renal function within 4 posttransplantation days. Postoperative bleeding (diffuse hemorrhage) requiring additional blood transfusions and radiological intervention (drainage procedure) occurred 9 days after transplantation. The patient was discharged on day 20 of hospitalization. Nine months after the kidney transplantation, the recipient's and donor's liver and kidney functions were normal. ABOi renal transplantation after liver transplantation can be successfully performed in patients with high baseline anti-ABO antibody titers after preconditioning with rituximab and PP, and quadruple immunosuppressive therapy. However, caution is required regarding an increased risk of bleeding complications.

Cardiac Resynchronization Therapy in Infant with Dilated Cardiomyopathy during Extracorporeal Membrane Oxygenator

Although heart transplantation is a final therapeutic option in pediatric patients with dilated cardiomyopathy (DCMP), the shortage of pediatric heart donors is a major obstacle. In adults with DCMP characterized by cardiac dyssynchrony, cardiac resynchronization therapy (CRT) is known to be an effective treatment option. However, there is a lack of evidence on the effectiveness of CRT in infants with DCMP. Several studies have reported improvement in hemodynamics and cardiac performance following CRT in infants with DCMP. Here, we report CRT in an infant with DCMP during extracorporeal membrane oxygenation with 5 months of follow-up.

Heart Transplantation in a Patient with Left Isomerism

We report the case of a 37-year-old man who suffered from biventricular failure due to left isomerism, inferior vena cava interruption with azygos vein continuation, bilateral superior vena cava, double outlet of right ventricle, complete atrioventricular septal defect, pulmonary stenosis, and isolated dextrocardia. Heart transplantation in patients with systemic venous anomalies often requires the correction and reconstruction of the upper & lower venous drainage. We present a case of heart transplantation in a patient with left isomerism, highlighting technical modifications to the procedure, including the unifocalization of the caval veins and reconstruction with patch augmentation.

Outcomes of Home Monitoring after Palliative Cardiac Surgery in Infants with Congenital Heart Disease

PURPOSE: Common conditions, such as dehydration or respiratory infection can aggravate hypoxia and are associated with interstage mortality in infants who have undergone palliative surgery for congenital heart diseases. This study was done to evaluate the efficacy of a home monitoring program (HMP) in decreasing infant mortality. METHODS: Since its inception in May 2010, all infants who have undergone palliative surgery have been enrolled in HMP. This study was a prospective observational study and infant outcomes during HMP were compared with those of previous comparison groups. Parents were trained to measure oxygen saturation, body weight and feeding volume and to contact the hospital through the hotline for emergency situations. Telephone counseling was conducted by clinical nurse specialists every week post discharge. RESULTS: Forty-one infants were enrolled in HMP. Nine hundred telephone counseling sessions were conducted. Seventy-three infants required telephone triage with the most common conditions being gastrointestinal (50.7%) and respiratory symptoms (32.9%). With HMP intervention, interstage mortality decreased from 18.6% (8/43) to 9.8% (4/41) (chi2=1.15, p=.283). CONCLUSION: Results indicate that active measures and treatments using the HMP decrease mortality rates, however further investigation is required to identify various factors that contribute to hemodynamic complications during the interstage period.

Living donor liver transplantation for patients with alcoholic liver disease

BACKGROUNDS/AIMS: Since most transplantation studies for alcoholic liver disease (ALD) were performed on deceased donor liver transplantation, little was known following living donor liver transplantation (LDLT). METHODS: The clinical outcome of 18 ALD patients who underwent LDLT from Febraury 1997 to December 2004 in a large-volume liver transplantation center was assessed retrospectively. RESULTS: The model for end-stage liver disease score was 23+/-11, and mean pretransplant abstinence period was 16+/-13 months, with 14 (77.8%) patients being abstinent for at least 6 months. Graft types were right lobe grafts in 11, left lobe grafts in 2 and dual grafts in 5. Graft to recipient body weight ratio was 0.94+/-0.16. The relapse rates in patients who did and did not maintain 6 months of abstinence were 7.1% and 50%, respectively (p=0.097). Younger recipient age was a significant risk factor for alcohol relapse (p=0.027). Five recipients with antibody to hepatitis B surface antigen (HBsAg) received core antibody-positive liver graft, but two of them showed positive HBsAg seroconversion. Overall 5-year patient survival rate following LDLT was 87.8%, with a 5-year relapse rate of 16.7%. CONCLUSIONS: Pretransplant abstinence for 6 months appears to be benefical for preventing posttransplant relapse. Life-long prophylactic measure should be followed after use of anti-HBc-positive liver grafts regardless of hepatitis B viral marker status of the recipient.

Analysis of Biliary Stricture after ABO Incompatible Adult Living Donor Liver Transplantation / 대한이식학회지

BACKGROUND: Despite recent improvements in survival outcome after ABO incompatible (ABOi) adult living donor liver transplantation (ALDLT), concerns about the incidence of biliary stricture (BS) still exist. However, reports on the actual incidence of BS have been scarce. METHODS: From November 2008 to August 2011, 77 cases of ABOi ALDLTs have been performed. We compared patient and graft survival and BS-free survival rates (BSFSR) between these ABOi ALDLTs and 734 ABO compatible (ABOc) ALDLTs performed during the same period. We also analyzed characteristics of BS in ABOi ALDLT. RESULTS: There was one mortality (1.3%) and one re-transplantation (due to small-for-size graft syndrome) among 77 cases of ABOi ALDLTs. Overall, 1-, 2-, and 3-year patient survival rates were 94.8%, comparable to ABOc ALDLTs (93.7%, 90.1%, 90.1%, P=0.20). BS occurred in 11 (13.8%) ABOi ALDLT patients. There were no significant differences in 1-, 2-, and 3-year BSFSR between ABOi and ABOc ALDLT patients (87.5% vs. 88.1%, 83.4% vs. 87.5%, and 83.4% vs. 86.4%, P=0.55). Among 10 patients with BS, four patients showed diffuse multiple intrahepatic strictures, which were linked to the death of two patients. CONCLUSIONS: The survival outcome of ABOi ALDLT is comparable to ABOc ALDLT. The incidence of BS of ABOi ALDLT was not superior to that of ABOc ALDLT. However, ABO incompatibility is related to the development of diffuse multiple intrahepatic BSs (rarely seen in ABOc ALDLT) and can cause graft failure and patient death.

The Application of a Bi-ventricular Assist Device for a Low Weight (2.4 kg) Neonate with Coarctation of the Aorta and Critical Aortic Stenosis / 대한흉부외과학회지

A 5-day-old neonate (body weight=2.4 kg) with coarctation of the aorta and critical aortic stenosis underwent an interventional balloon valvuloplasty for aortic stenosis. During the intervention, cardiac arrest occurred due to injury of the right carotid artery by the guide wire. An extracorporeal membrane oxygenator (ECMO) was applied. After 1 day's support, total surgical correction was achieved; however, in the immediate postoperative period, cardiac function was severely depressed. We applied a bi-ventricular assist device (bi-VAD) instead of an ECMO and we were able to wean the patient off the bi-VAD device after 3 days' support. The patient was discharged without severe complications.

Transplantation of an Extremely Oversized Heart after Prolonged Extracorporeal Membrane Oxygenation Assistance in a 3-month-old / 대한흉부외과학회지

According to the 2007 International Society for Heart and Lung Transplantation (ISHLT) report, a congenital diagnosis, infantile transplantation and being on extracorporeal membrane oxygenation (ECMO) at the time of transplant are risk factors for mortality for the patients who undergo a heart transplant, and a large body weight ratio also increases the risk of mortality. The patient of this case underwent a Ross operation and mitral valve repair due to left ventricle outflow track obstruction and mitral regurgitation. But the baby was treated with ECMO due to heart failure after the operation. When he was 3-months-old and had been on 30 days of ECMO, he underwent a heart transplant with a heart that had a high donor-recipient weight ratio (4.42). We present this case from a technical standpoint and we include a review of the relevant literature.

The Dynamic and Histologic Changes of Variously Fixed Bovine Pericardiums Specimens after Mechanical Fatigue Stimuli / 대한흉부외과학회지

BACKGROUND: As cardiovascular operations become more complex and sophisticated, there is an increasing need for various bioprostheses for use as components of blood vessels and heart valves. We developed a fatigue stimuli test instrument to objectively evaluate the mechanical durability of a bioprosthesis, and we tested several currently- known processing methods for bovine pericardium and we then compared the results. MATERIAL AND METHOD: Fresh bovine pericardium was collected at the butcher shop with using aseptic technique, and each piece of pericardium was fixated and/or decellularized by 16 representative methods. We measured the permeability and compliance of the processed bovine pericardium samples, and measured them again after exposure to the fatigue stimuli. All the pieces of pericardium underwent microscopic examinations before and after the fatigue stimuli. RESULT: A mixture of glutaraldehyde and solvent treatment showed better mechanical durability than did the single glutaraldehyde treatment. High concentration glutaraldehyde treatment showed equal or no worse results than did low concentration glutaraldehyde treatment. After SDS (sodium dodecylsulfate) decellularization, the mechanical property of the bioprosthesis became much worse (20~190 times) and the mechanical durability to the fatigue stimuli was also very poor. CONCLUSION: We obtained the basic durability data after various fixation methods with using a home-made fatigue test instrument.

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.

Mechanism of Humoral and Cellular Immune Modulation Provided by Porcine Sertoli Cells

The understanding of main mechanisms that determine the ability of immune privilege related to Sertoli cells (SCs) will provide clues for promoting a local tolerogenic environment. In this study, we evaluated the property of humoral and cellular immune response modulation provided by porcine SCs. Porcine SCs were resistant to human antibody and complement-mediated formation of the membrane attack complex (38.41+/-2.77% vs. 55.02+/-5.44%, p=0.027) and cell lysis (42.95+/-1.75% vs. 87.99 +/-2.25%, p<0.001) compared to immortalized aortic endothelial cells, suggesting that porcine SCs are able to escape cellular lysis associated with complement activation by producing one or more immunoprotective factors that may be capable of inhibiting membrane attack complex formation. On the other hand, porcine SCs and their culture supernatant suppressed the up-regulation of CD40 expression (p<0.05) on DCs in the presence of LPS stimulation. These novel findings, as we know, suggest that immune modulatory effects of porcine SCs in the presence of other antigen can be obtained from the first step of antigen presentation. These might open optimistic perspectives for the use of porcine SCs in tolerance induction eliminating the need for chronic immunosuppressive drugs.

Establishment of Featal Heart Surgery with an Improvement of the Placental Blood Flow in Cardiopulmonary Bypass Using Fetal Lamb Model / 대한흉부외과학회지

BACKGROUND: We tested the effect of indomethacine and total spinal anesthesia on the improvement of placental flow during cardiopulmonary bypass on fetal lamb. MATERIAL AND METHOD: Twenty fetuses at 120 to 150 days of gestation were subjected to bypass via trans-sternal approach with a 12 G pulmonary arterial cannula and 14 to 18 F venous cannula for 30 minutes. All ewes received general anesthesia with ketamine. In all the fetuses, no anesthetic agents were used except muscle relaxant. Ten served as a control group in which placenta was worked as an oxygenator during bypass (Control group). The remainder worked as an experimental group in which pretreatment with indomethacine and total spinal anesthesia was performed before bypass with the same extracorporeal circulation technique as control group (Experimental group). Observations were made every 10 minutes during a 30-minute bypass and 30-minute post bypass period. RESULT: Weights of the fetuses ranged from 2.2 to 5.2 kg. In Control group, means of arterial pressure decreased from 44.7 to 14.4 mmHg and means of PaCO2 increased from 61.9 to 129.6 mmHg at each time points during bypass. Flow rate was suboptimal (74.3 to 97.0 ml/kg/min) during bypass. All hearts fibrillated immediately after the discontinuation of bypass. On the contrary, in Experimental group, means of arterial pressure reamined higher (45.8 to 30 mmHg) during bypass (p<0.05). Means of PaCO2 were less ranging from 59.8 to 79.4 mmHg during bypass (p<0.05). Flow rates were higher (78.8 to 120.2 ml/ kg/min) during bypass (p<0.05). There were slower deterioration of cardiac function after cessation of bypass. CONCLUSION: In this study, we demonstrated that the placental flow was increased during fetal cardiopulmonary bypass in the group pretreated with indomethacine and total spinal anesthesia. However, further studies with modifications of the bypass including a creation of more concise bypass circuit, and a use of axial pump are mandatory for the clinical application.

Aortic Valvuloplasty in Pediatric Age / 대한흉부외과학회지

BACKGROUND: In this study, we retrospectively analyzed the outcomes of aortic valvuloplasty in pediatric age. MATERIAL AND METHOD: Between January 1993 and March 2004, 35 patients underwent aortic valvuloplasty for aortic stenosis (AS) or aortic regurgitation (AR). The mean age was 81.1+/-61.5 (1~223) months. The mean follow up was 50.8+/-30.2 (3~121) months. Nine patients had AS, 21 had AR, and 6 had AS and AR. Valve morphology was tricuspid in 24 patients, bicuspid in 9, quadricuspid in 1, and unicuspid in 1. The mean peak pressure gradients of AS were 72.0+/-33.0 mmHg, and the mean grades of AR were 3.1+/-0.9. RESULT: There was one late mortality without early mortality. After operation, AS improved with mean peak pressure gradients of 23.5+/-21.0 mmHg (p<0.05), and AR improved with mean grades of 1.9+/-0.8 (p<0.05). At mean follow up of 35.0+/-23.0 months, AS maintained with mean peak pressure gradients of 31.5+/-24.0 mmHg, but AR progressed with mean grades of 2.8+/-1.3 (p<0.05). Reoperation was required in 6 patients 38.3+/-21.8 months after the original operation. The actuarial figures for freedom from reoperation at 2, 5 and 8 years were 96.9+/-3.1%, 79.5+/-5.5%, and 56.8+/-11.4%, respectively. Age at operation, presence of AS, preoperative severity of AS or AR, and morphology of aortic valve were not significant risk factors for reoperation, and improvement of AS or AR. CONCLUSION: Aortic valvuloplasty showed good immediate postoperative valve function. Aortic valvuloplasty offers children many years with tolerable valve function and allows to postpone aortic valve replacement or Ross procedure in pediatric patients.