The long-term result of total repair for tetralogy of Fallot

OBJECTIVE

The objective of this study was to evaluate the long-term outcome of total repair for tetralogy of Fallot.

METHODS

Between April 1986 and December 2007, a total of 734 patients underwent total repair for tetralogy of Fallot. There were 444 males and 290 females. The median age and weight were 17.2 months (0.4-329.6 months) and 9.5kg (2.6-53.5kg). The median follow-up duration was 150.2 months (1.9-356.2 months).

RESULTS

There were 27 early deaths (3.7%) and 13 late deaths. A longer cardiopulmonary bypass time and the use of total circulatory arrest were risk factors for early death. The overall survival rate was 94.8%, 92.8% and 92.8% at 10, 20 and 25 years, respectively. The presence of pulmonary atresia was a risk factor for long-term survival. Re-operation or re-intervention was required in 224 patients (31.7%). The most common causes of re-operation or re-intervention were pulmonary regurgitation in 109 patients and branch pulmonary artery stenosis in 127 patients. Freedom from re-operation or re-intervention rate was 81.5%, 68.9% and 46.6% at 5, 10 and 20 years, respectively. Reconstruction of the right ventricular outflow tract with other than non-trans-annular repair and branch pulmonary arterioplasty at the time of total repair were the risk factors for late re-operation or re-intervention. The use of a monocusp patch was not associated with early mortality or re-operation. At the latest follow-up, most patients were in the New York Heart Association functional class 1 or 2.

CONCLUSIONS

The long-term outcome of total repair for tetralogy of Fallot was satisfactory. A longer cardiopulmonary bypass time and the use of deep hypothermic circulatory arrest were associated with early mortality. The patients with pulmonary atresia have poorer late survival. Preservation of the pulmonary annulus can reduce the re-operation rate. A small pulmonary artery that requires augmentation may increase the risk of re-operation. The use of a monocusp in patients who underwent trans-annular repair has no benefit for early survival, the postoperative recovery and avoidance of re-operation. Age was not a risk factor for early mortality and re-operation.

Outcomes of biventricular repair for congenitally corrected transposition of the great arteries

BACKGROUND

This study was undertaken to evaluate long-term results of biventricular repairs for congenitally corrected transposition of the great arteries, and to analyze the risk factors that affect mortality and morbidity.

METHODS

Between 1983 and 2009, 167 patients with congenitally corrected transposition of the great arteries underwent biventricular repairs. The physiologic repairs were performed in 123 patients, and anatomic repairs in 44. Average follow-up was 9.3 +/- 6.6 years.

RESULTS

Kaplan-Meier estimated survival was 83.3% +/- 0.5% at 25 years in biventricular repair. In anatomic repair, left ventricular training and right ventricular dysfunction had negative impact on survival, but bidirectional cavopulmonary shunt had positive impact on survival. The reoperation-free ratio was 10.1% +/- 7.8% at 22 years after physiologic repair, and 46.2% +/- 12.4% at 15 years after anatomic repair (p = 0.885). Freedom from any arrhythmia was 49.6% +/- 7.5% at 22 years after physiologic repair, and 60.8% +/- 14.8% at 18 years after anatomic repair (p = 0.458). Freedom from systemic atrioventricular valve and ventricular dysfunction as well as tricuspid valve and right ventricular dysfunction was significantly higher in anatomic repair than in physiologic repair.

CONCLUSIONS

Long-term results of biventricular repair were satisfactory. Patients presenting with right ventricular dysfunction or need for left ventricular training represent a high-risk group of anatomic repair for which selection criteria are particularly important. Late functional outcomes of anatomic repair were excellent compared with physiologic repair. Anatomic repair is the procedure of choice for those patients if both ventricles are adequate or if surgical technique is modified with the help of additional a bidirectional cavopulmonary shunt.

Long-term outcomes after an arterial switch operation for simple complete transposition of the great arteries

BACKGROUND AND OBJECTIVES

Although coronary artery obstruction, aortic insufficiency (AI), and pulmonary stenosis (PS) have been reported after arterial switch operation (ASO), limited long-term studies on ASO exist. Our study aimed to examine long-term outcomes after ASO for simple complete transposition of the great arteries (TGA).

SUBJECTS AND METHODS

All 108 patients with simple complete TGA who underwent ASO at Seoul National University Children's Hospital between 1987 and 2004 were enrolled. We retrospectively reviewed the patients' medical records and the results of various functional and imaging studies.

RESULTS

Among 108 cases of ASO for simple TGA, 96 have been followed-up through the present time (mean follow-up duration was 11.7+/-8.6 years: range= 4 to 23 years). The 20-year rates of freedom from significant AI, PS, and coronary obstruction were 78.6%, 67.8%, and 95.8%, respectively. AI showed a tendency to progress as follow-up time increased in 21.4% of the population studied (p=0.014); however, AS, PS, and PI showed no such progression. Late coronary artery occlusion was not associated with the initial coronary arterial pattern. Re-operations were done for 13 patients (13.5%) at an average of 8+/-4.3 years after ASO. The survival rate was 96%, while the re-operation-free was 90% at 10 years and 83% at 20 years. Most patients showed normal physical growth with good activity {98%; New York Heart Association (NYHA) class 1 activity} and normal development (96%).

CONCLUSION

Although most patients showed normal physical growth and development after successful ASO, meticulous long-term follow-up is necessary because of progressive AI and coronary complications.

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.

Extracardiac Fontan with T-shape conduit in non-confluent pulmonary arteries

A 34 months-old male patient with double inlet right ventricle with nonconfluent pulmonary arteries who underwent successful extracardiac fenestarated Fontan procedure using pre-designed T-shaped PTFE vascular graft after multi-step rehabilitation of the diminutive hilar pulmonary arteries. At first we performed 6 mm confluent pulmonary artery vascular graft implantation with 4 mm BT shunt at patient's 4 weeks old. At 9 months of patient, we upsized the confluent pulmonary arterial graft to 8 mm with bidirectional cavopulmonary connection, and, at 34 months, we performed extracardiac conduit Fontan procedure with pre-designed T-shape conduit including the confluent pulmonary arterial portion at last. Patient shows excellent functional status and development.

Follow-up of Shelhigh porcine pulmonic valve conduits

BACKGROUND

We implanted Shelhigh porcine pulmonic valve conduits because of the limited availability of homografts in our country. The aim of this study was to evaluate the short-term results of SPVC.

METHODS

From November 2002 to July 2005, the Shelhigh porcine pulmonic valve conduit was implanted in 73 patients (81 procedures) in the right ventricular outflow tract to correct congenital heart diseases. Operative procedures were Rastelli operation in 65, anatomic correction of atrioventricular discordance in 5, and Ross operation in 3. Age at operation was 6.8 +/- 7.5 years, including 11 patients under 1 year. The median conduit size was 18 mm (range, 12 to 24 mm).

RESULTS

There was no operative mortality and 1 nonconduit-related late death (mean follow-up, 11.3 +/- 10.7 months). Ten conduits (12.3%, 7 patients) were removed at a median of 9.6 months (range, 2.5 to 25.4) owing to obstruction in 9 and pseudoaneurysm in 1. In the explanted conduits, we found a prominent intimal peel at the distal anastomosis without leaflet calcification. Freedom from reoperation at 24 months was 87% +/- 11.7% in large-sized conduits (>or=18 mm) and 62.8% +/- 10.6% in small-sized conduits (<or=16 mm). Especially, 12-mm sized conduit showed 33.3% freedom from reoperation during the first 12 months of follow-up.

CONCLUSIONS

On the basis of our short-term results, Shelhigh porcine pulmonic valve conduits are not satisfactory. Small-sized conduits (<or=16 mm) fail earlier; large-sized conduits (>or=18 mm) fail after 2 years of implantation due to intimal peel formation at the distal segment.

Establishment and characterization of porcine Sertoli cell line for the study of xenotransplantation

BACKGROUND

An understanding of the main mechanism that determines the ability of immune privilege related to Sertoli cells (SC) will provide clues for promoting a local tolerogenic environment. In this report, we established neonatal porcine SC line and evaluated their characteristics.

METHODS

SC line was established following the transfection of primary SC (NPSC) from the testis of neonatal pig with plasmid pRNS-1 carrying genes for neomycin resistance and the SV40 large T antigen. Immunohistochemistry and RT-PCR were performed to evaluate the character of immortalized SC lines.

RESULTS

Our immortalized SC line (iPS) proliferated stably and had a phenotype similar to NPSC, as indicated by the immunoexpression of follicle stimulating hormone receptor (FSHR), and mRNA expression of androgen receptor (AR), and Wilms' tumor antigen (WT1). Interestingly, NPSC and iPS expressed mRNA of complement regulatory proteins (CRP) such as membrane cofactor protein (CD46), decay accelerating factor (DAF or CD55), and protectin (CD59), but CD59 mRNA expression was negligible in iPS.

CONCLUSION

These results suggest that iPS, immortalized by the introduction of SV40 T, retain their original characteristics, except for the relatively low expression of CD59, and that they may be useful for future in vitro and in vivo studies of immune privilege mechanisms related to SC.

Effect of immature dendritic cell injection before heterotropic cardiac allograft

Although dendritic cells (DCs) are unrivaled for initiation of immune responses, the immunomodulatory capacity of chemically fixed DC has not been thoroughly evaluated. We monitored the tolerogenic capacity of chemically fixed DCs using allogeneic heart transplantations. Bone marrow progenitors were differentiated into immature DCs which were then chemically fixed and injected intravenously into recipient mice at 14 days before allogeneic heart transplantation. Chemically fixed DCs markedly prolonged graft survival in the major histocompatibility complex (MHC) I/II mismatch cardiac transplantation (B6 --> B10.A; median survival time [MST] 12.5 days vs >70 days). T cells that encountered chemically fixed DCs showed attenuated apoptotic cell death and inactivated phenotypes after allogeneic heterotropic heart transplantation. Furthermore, when DCs from interleukin (IL)-10-/- mice were treated, the in vitro T-cell response was greater than that from IL-12-/- mice. We have suggested that the chemically fixed DCs may mediate peripheral T-cell tolerance, with therapeutic potential for allogeneic transplantation.

Role of complement regulatory proteins in the survival of murine allo-transplanted Sertoli cells

Sertoli cells (SC) are known to contain immunoprotective properties, which allow them to survive as allografts without the use of immunosuppressive drugs. Experiments were designed to determine which factors are related to prolonged survival of allogeneic SC. Balb/c derived Sertoli (TM4) and colon cancer (CT-26) cell lines were implanted beneath the kidney capsule of non-immunosuppressed C57BL/6 mice and compared their survival as allografts. Compared to TM4 graft, which survived more than 7 days after transplantation, CT-26 showed massive infiltration of polymorphonuclear cells, necrosis and enlargement of draining lymph nodes. Cultured cell lines showed no differences in their expression patterns of FasL, TGF beta1, clusterin and two complement regulatory proteins (CRP, i.e., membrane cofactor protein, MCP; decay accelerating factor, DAF), but protectin (CD59), another member of CRP was expressed only on TM4. These results suggest that CD59 and unknown factors may contribute to the prolonged survival of SC in non-immunoprivileged sites.

Comparison of lateral tunnel and extracardiac conduit Fontan procedure

The purpose of this study was to compare the outcomes of lateral tunnel (LT) and extracardiac conduit (ECC) Fontan procedures at a single institution. From April 1995 to December 2006, 165 Fontan procedures were performed (67 LT, 98 ECC). Pre-, intra- and postoperative variable values were compared between two different techniques. Operative mortality was 5 (3 LT, 2 ECC). Immediate postoperative transpulmonary gradient (LT 8.5+/-ECC 2.5 vs. 6.6+/-2.4 mmHg) and central venous pressure (LT 18.3+/-3.8 vs. ECC 15.6+/-2.4 mmHg) showed significant difference (P<0.001). The LT patients had a higher incidence of sinus node dysfunction in the postoperative period (22.4% vs. ECC 11.2%; P=0.05). Mean follow-up was 74.1+/-31.5 months in LT, and 31.7+/-28.1 months in ECC patients. There was one late death. Actuarial survival at 10 years is 92% for LT, and 89% for ECC patients (P=0.796). The LT and ECC, both, showed comparable early and mid-term outcomes in operative morbidity and mortality, postoperative hemodynamics, survival. Use of ECC for modified Fontan operation reduces the risk of sinus node dysfunction and shows better outcome of immediate postoperative hemodynamics.

The effect of gynaecological laparoscopic surgery on cerebral oxygenation

During gynaecological laparoscopic surgery, alterations in cerebral blood flow and intracranial pressure are frequently reported. These changes affect cerebral perfusion pressure and thus may affect cerebral oxygenation. In this prospective study, the effect of gynaecological laparoscopic surgery on cerebral oxygenation was examined by following the changes in regional cerebral oxygen saturation (rSo2). Twenty-four female patients were enrolled. The mean rSo2 was 65.5 +/- 5.4% at baseline before surgery, 60.8 +/- 5.6% when the patient was placed in the Trendelenburg position, 57.1 +/- 9.3% after creation of pneumoperitoneum, and 64.0 +/- 7.3% after the completion of surgery. During the period of pneumoperitoneum, rSo2 fell below 50% in two hypercapnic patients. In comparison with baseline, rSo2 declined significantly in the Trendelenburg position. The creation of pneumoperitoneum itself did not decrease the average rSo2 value further unless the patients were hypercapnic.

Age-dependent expression of immune-privilege and proliferation-related molecules on porcine Sertoli cells

BACKGROUND

The immunoprotective nature of the testes has prompted numerous investigations into their supportive roles during allogeneic or xenogeneic cellular grafts. However, the optimal developmental stage of these cells in terms of maximum efficacy for cellular grafts has not been elucidated. In this study, the time-dependent expressions of immune-privilege- and proliferation-related molecules in Sertoli cells were determined.

METHODS

To investigate the time course of the expression of proteins related to immune privilege and proliferation, immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed using testes of 18 Yorkshire pigs from birth to 20 weeks of age. We included fas ligand (FasL), transforming growth factor beta1 (TGF-beta1) and clusterin as the immune-protective molecules, and follicle stimulating hormone receptor (FSHR), p27Kip1, GATA-4 and Wilm's tumor antigen (WT1) as Sertoli cell proliferation markers. RT-PCR was used to complement histological assessment.

RESULTS

The expression of FasL in Sertoli cells gradually increased with age, whereas TGF-beta1 showed the reverse pattern, and clusterin expression showed no age-related difference. p27Kip1 showed a gradual increase in its expression from week 12, but GATA-4 showed earlier postnatal expression from birth to week 12. WT1 expression gradually increased from week 16.

CONCLUSION

We confirmed the age-dependent expression of immune-privilege- and proliferation-related molecules in porcine Sertoli cells. These data may be useful for determining the optimal time for harvesting Sertoli cells with respect to maximal immunoprotection and proliferative activity.

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.

Cyclosporine-induced renal injury induces toll-like receptor and maturation of dendritic cells

BACKGROUND

The toll-like receptor (TLR) is stimulated by not only pathogen-associated molecular patterns but also endogenous TLR ligands provided by injured cells. The influence of cyclosporine A (CsA)-induced renal injury on TLR expression and subsequent signaling pathway was evaluated.

METHODS

Induction of chronic CsA nephropathy was made by administering CsA (15 mg/kg/day) for 28 days in rats. The TLR2 and TLR4 mRNA and protein expression, TLR-signaling pathway (MYD88, NF-kappaB and AP-1), putative TLR ligand (heat shock protein 70 [HSP70]), and maturation of dendritic cells were evaluated in CsA-treated rat kidneys.

RESULTS

Long-term CsA treatment upregulated TLR2 and TLR4 mRNA and protein expression on renal tubular cells, and these were accompanied by increased MYD88, NF-kappaB and AP-1 expression. Putative TLR ligand (HSP70) was also significantly increased in CsA-treated rat kidney compared with vehicle-treated rat kidney. CsA-treatment increased expression of TNF-alpha mRNA, the number of dendritic cells, and expression of MHC class II antigen. Double-labeling of markers of dendritic cells and MHC class II antigen revealed that matured dendritic cells increased in CsA-treated rat kidney.

CONCLUSIONS

CsA-induced renal injury stimulates components of innate immunity, and this finding suggests close association between CsA-induced renal injury and activation of innate immunity.

Pulmonary root translocation for repair of Taussig-Bing anomaly with interrupted arch

Anterior translocation of the pulmonary root was used as a new approach to the staged repair of Taussig-Bing anomaly with an interrupted aortic arch. It was performed to construct the right ventricle outflow tract with intraventricular baffling of the left ventricle to the aorta as the second stage operation after repair of the interrupted arch and pulmonary artery banding. This technique allows minimization of pulmonary regurgitation and has the major theoretical advantage for growth potential, which could diminish the need for reoperation.

MHC expression in a human adult stem cell line and its down-regulation by hCMV US gene transfection

Due to their unique capacity to self-renew and for multiple differentiation, stem cells are considered promising candidates for cell replacement therapy in many devastating diseases. However, studies on immune rejection, which is a major problem facing successful stem cell therapy, are rare. In this study, we examined MHC expression in the M13SV1 cell line, which has previously been shown to have stem cell properties and to be non-tumorigenic, in order to determine whether human adult stem cells might be rejected after transplantation. Our results show low expression levels of MHC class I molecules on the surface of these cells. An induction of MHC class I expression was observed when the cells were treated with IFN-gamma. Maximal induction of MHC class protein expression was observed at 48 h after treatment with concentrations above 5 ng/ml of IFN-gamma. Elevated MHC class I levels were sustained for 72 h after withdrawing IFN-gamma. Therefore, we introduced human cytomegalovirus (hCMV) US genes, which are known to be able to reduce MHC class I expression on the cell surface after infection, into M13SV1 cells. Cells transfected with the hCMV US2, US3, US6 or US11 genes exhibited a reduction (40-60%) of MHC class I expression compared with mock-transfected cells. These results suggest that human adult stem cells are capable of expressing high levels of MHC class I proteins, and thus may be rejected on transplantation unless they are modified. In addition, viral stealth mechanisms can be exploited for stem cell transplantation.

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.