Total cavopulmonary connection with an extracardiac conduit: experience with 100 patients

BACKGROUND: In the Fontan procedures total cavopulmonary connection with an extracardiac conduit is a concern. The potential benefits of an extracardiac conduit may be the avoidance of postoperative supraventricular arrhythmias over the long-term, hemodynamic benefits due to laminar flow, possibility of completion without anoxic arrest, and applicability to anomalous systemic or pulmonary venous return, or both anomalous systemic and pulmonary venous return. We demonstrate early to midterm results of total cavopulmonary connection with an extracardiac conduit. METHODS: Between March 1994 and February 2000, a total of 100 patients underwent total cavopulmonary connection with an extracardiac conduit. In 27 patients, who underwent a single stage total cavopulmonary connection operation, 7 were done without palliation. Seventy-three patients had undergone a bidirectional Glenn shunt before completion of the total cavopulmonary connection. We used an expanded polytetrafluoroethylene tube graft as the extracardiac conduit. RESULTS: Cardiopulmonary bypass time was 133.2+/-55.2 minutes. Myocardial ischemic time was 38.5+/-23.2 minutes in 40 patients who needed cardioplegic cardiac arrest for intracardiac procedures. Intraoperative fenestration was done in only 1 patient. There were no operative deaths. During follow-up of 37.3 months, there were 5 late deaths. When compared with the patients treated by the lateral tunnel technique in our institute, there was no significant difference in actuarial survival rate, but the event free rate of the extracardiac conduit group was significantly superior to the lateral tunnel group. CONCLUSIONS: Total cavopulmonary connection with the extracardiac conduit produced good results in short to midterm follow-up.     

Five- to fifteen-year follow-up of fresh autologous pericardial valved conduits

OBJECTIVE: Evaluate long-term results of autologous pericardial valved conduits in the pulmonary outflow. METHODS: Between June 1983 and October 1993, 82 conduits were placed in the outflow of the venous ventricle. Patients who received homografts (n = 2 patients), heterografts (n = 3 patients), and valveless conduits (n = 19 patients) and those patients who died within 90 days after the operation were excluded. Fifty-four survivors of pulmonary outflow reconstruction with fresh autologous pericardial valved conduits were followed up from 5 to 15 years (mean, 7.47 +/- 2.8 years). Diagnosis include d -transposition of great arteries (n = 16 patients), L -transposition of great arteries (n = 14 patients), tetralogy of Fallot, pulmonary atresia with ventricular septal defect (n = 11 patients), truncus arteriosus (n = 10 patients), and double-outlet ventricle (n = 3 patients). Implantation age ranged from 0.25 to 24 years (mean, 5.2 +/- 4.2 years). Median conduit diameter was 16 mm. Two-dimensional echocardiographic Doppler evaluations were made yearly; 9 patients underwent cardiac catheterization. Reintervention for stenosis was indicated when the pressure gradient exceeded 50 mm Hg. RESULTS: Three late deaths were unrelated to the conduit. Thirty-five autologous pericardial valved conduits increased in diameter (1-7 mm), remained unchanged in 15 patients, and reduced 1 to 2 mm in 4 patients. The median diameter was 18 mm at the last evaluation (P =.0001). Eight patients required conduit-related reoperation 3 to 8 years after the implantation. Two patients underwent balloon dilation of the autologous pericardial valved conduit. No conduit had to be replaced. Freedom from reintervention at 5 and 10 years was 92% and 76%, being 100% at 10 years for conduits larger than 16 mm at time of implantation. CONCLUSIONS: Autologous pericardial valved conduits show excellent long-term results and compare favorably with other conduits.     

Midterm follow-up of the status of Gore-Tex graft after extracardiac conduit Fontan procedure

Objective: Extracardiac conduit Fontan procedure has some theoretical advantages over other types of Fontan procedures, such as optimized flow dynamics, a lower frequency of arrhythmias, and technical ease of procedure. However, lack of growth potential and thrombogenicity of the artificial conduit is the main concern and can possibly lead to reoperation for the conduit stenosis. In this study, we investigated the change and the status of the Gore-Tex graft used in extracardiac conduit Fontan procedure. Methods: Between 1996 and 2005, 154 patients underwent extracardiac conduit Fontan procedure using Gore-Tex graft. Among these, 46 patients underwent cardiac catheterization during follow-up period. We measured the internal diameter of the conduit and inferior vena cava angiographically. Results: Mean follow-up duration was 36.1 ± 19.7 months. The conduit diameter used was 16 mm in 10 patients, 18 mm in 16, 20 mm in 14, 22 mm in 4, and 24 mm in 2 patients. The mean conduit-to-inferior vena cava cross-sectional area ratio was 1.25 ± 0.33. According to the conduit size used, this ratio was 1.03 ± 0.17 for 16 mm conduits, 1.33 ± 0.37 for 18 mm, 1.33 ± 0.36 for 20 mm, 1.28 ± 0.26 for 22 mm, and 1.05 ± 0.06 for 24 mm conduits (p < 0.05, 16 mm vs 18 mm and 20 mm). The mean percent decrease of the conduit cross-sectional area was 14.3 ± 8.5%, and this did not differ significantly according to the conduit size (p = 0.82). Follow-up duration and the percent decrease of the conduit cross-sectional area did not show significant correlation (r = 0.22, p = 0.14). There was no reoperation due to conduit stenosis. Conclusions: During midterm follow-up of about 3 years, the conduit cross-sectional area decreased by 14%, and this did not differ according to the conduit size used. The extent of decrease of the conduit cross-sectional area remained stable irrespective of the follow-up duration. Sixteen millimeters conduit showed no evidence of clinically significant stenosis, but careful follow-up is warranted because of the possible conduit stenosis relative to the patients’ somatic growth.     

Valved and nonvalved right ventricular--pulmonary arterial extracardiac conduits. An experimental comparison

Extracardiac conduits are essential in operations for congenital discontinuity between the right ventricle and the pulmonary artery. The disturbing degree of obstruction reported in clinical series of extracardiac conduits containing porcine valves has been attributed in part to early valve deterioration and the development of a thick neonintimal lining within the Dacron graft. This study compares the hemodynamic differences and the thickness of the neointimal lining in right ventricular extracardiac conduits with and without a porcine valve. Woven Dacron conduits (16 mm) were implanted in 15 adult mongrel dogs, and then the proximal pulmonary artery was occluded with Dacron tape. In six dogs, the extracardiac conduit contained a porcine valve, whereas in the other nine it did not. Cardiac output, transconduit gradient, and resistance were measured at operation and 6 and 12 months postoperatively in both groups. No hemodynamic differences were noted. After 1 year, the thickness of the neointimal lining was threefold greater in valved conduits (1,370 +/- 313.1 mu versus 367 +/- 28.07 mu, p less than 0.005). The neointima along the Dacron graft was thickest proximal and distal to the porcine valve. The luminal peel in valved conduits contained fenestrations and intimal flaps, similar to those observed clinically. In our model, a porcine valve in a right ventricular extracardiac conduit is associated with intimal hyperplasia not seen in nonvalved conduits. If the pulmonary vascular resistance is normal, then the absence of a valve within the conduit does not significantly change hemodynamics and may warrant clinical application to prevent late conduit obstruction.     

Arterial conduits for hepatic artery revascularisation in adult liver transplantation

Arterial complications after orthotopic liver transplantation (OLT), including hepatic artery thrombosis (HAT), are important causes of early graft failure. The use of an arterial conduit is an accepted alternative to the utilisation of native recipient hepatic artery for specific indications. This study aims to determine the efficacy of arterial conduits and the outcome in OLT. We retrospectively reviewed 1,575 cadaveric adult OLTs and identified those in which an arterial conduit was used for hepatic revascularisation. Data on the primary disease, indication for using arterial conduit, type of vascular graft, operative technique and outcome were obtained. Thirty-six (2.3%) patients underwent OLT in which arterial conduits were used for hepatic artery (HA) revascularisation. Six of these were performed on the primary transplant, while the rest (n=30) were performed in patients undergoing re-transplantation, including six who had developed hepatic artery aneurysms. The incidence of arterial conduits was 0.4% (6/1,426 cases) in all primary OLTs and 20.1% (30/149 cases) in all re-transplants. Twenty-nine procedures utilised iliac artery grafts from the same donor as the liver, six used iliac artery grafts from a different donor, and a single patient underwent a polytetrafluoroethylene (PTFE) graft. Two techniques were used: infra-renal aorto-hepatic artery conduit and interposition between the donor and recipient native HAs, or branches of the HAs. The 30-day mortality rate for operations using an arterial conduit was 30.6%. Three conduits thrombosed at 9, 25 and 155 months, respectively, but one liver graft survived without re-transplantation. The arterial conduits had 1- and 5-year patency rates of 88.5% and 80.8%. The 1- and 5-year patient survival rates were 66.7% and 44%. We can thus conclude that an arterial conduit is a viable alternative option for hepatic revascularisation in both primary and re-transplantation. Despite a lower patency rate than that of native HA in the primary OLT group, the outcomes of arterial conduit patency and patient survival rates are both acceptable at 1 and 5 years, especially in the much larger re-OLT group.     

Depopulated vena caval homograft: a new venous conduit

OBJECTIVE: Completion of the Fontan procedure is frequently performed by using an extracardiac conduit between the inferior vena cava and the pulmonary artery. Most centers use a polytetrafluoroethylene graft for the extracardiac conduit, and because re-endothelialization is unlikely, anticoagulation is used for a variable period. This study explores the use of an alternate large-caliber venous conduit. METHODS: The superior vena cava was replaced in 8 minipigs with either a polytetrafluoroethylene interposition graft (2 pigs) or a depopulated (acellular), cryopreserved superior vena caval homograft (6 pigs). After 6 months, the animals were killed, and the grafts were examined for patency and histology, including immunostaining. No anticoagulation was used. RESULTS: Polytetrafluoroethylene grafts have a cross-sectional luminal narrowing, ranging from 16% to 40%. Histology showed only partial intimal ingrowth, with excessive subendothelial fibrosis and early calcification. In contrast, the depopulated venous homografts showed minimal luminal narrowing, ranging from 2% to 9%. These grafts were completely repopulated by the recipient with an endothelial lining, which stained positively for factor VIII, and a subendothelial region appropriately recellularized by myofibroblasts, which stained positively for smooth muscle actin and procollagen. There was no evidence of an immune response to the venous homografts, as judged by staining for T-cell surface antigen, CD4, and CD8. Thrombus was not seen in any of the grafts. CONCLUSION: Depopulated, cryopreserved vena caval homografts might be superior conduits for cavopulmonary connection during completion of the Fontan operation by using the extracardiac conduit technique.     

The role of arterial conduits for revascularisation in adult orthotopic liver transplantation

The successful outcome in orthotopic liver transplantation (OLT) is critically dependent on the uncompromised hepatic graft blood inflow. Arterial conduits represent a good solution in cases where conventional revascularisation is not possible. The purpose of this systematic review is to analyse the published evidence on the use of arterial conduits in adult OLT. After review of the Pubmed and EMBASE databases, 19 relevant studies were identified and analysed.Even though patient survival was comparable, most large studies reported worse 1-, 3- and 5-year graft survival rates compared to grafts with standard arterial revascularisation. Primary grafts were more commonly affected than re-grafts. Early and late hepatic artery thrombosis occurred more commonly, while the use of an arterial conduit was identified as an independent risk factor. The overall biliary complications were comparable, however, ischaemic cholangiopathy was encountered about 3 times more in patients with arterial conduits and strongly correlated with the occurrence of late HAT.In conclusion, the use of arterial conduit is a useful option in adult OLT in cases that the conventional revascularisation technique cannot be used or results in suboptimal arterial inflow. More studies directly addressing issues such as pre-operative evaluation regarding the need for arterial conduit, the types of vessels used, positioning of the conduit and post-operative management are required.     

Intraoperative measurement of graft blood flow - a necessity in liver transplantation

Abstract Portal venous and hepatic arterial flow was measured intraop-eratively in the 70 most recent patients undergoing liver transplantation in our institution. Impaired graft flow due to vascular abnormalities was detected in six patients. One patient suffered from arterial steal due to stenosis of the recipient celiac trunk with blood shunting from the hepatic to the splenic artery. Ligation of the recipient hepatic artery restored the arterial graft flow. In two patients we found reduced portal venous flow due to large portosystemic collaterals. The collaterals accountable for the impaired portal flow were identified and ligated, which restored portal venous graft flow. Excessive sensitivity of the portal venous flow to the position of the graft was found in a 6-month-old boy. Portal venous flow varied considerably, depending upon the position of the graft, and intraoperative flow measurement allowed the best position of the graft to be identified. Two patients developed arterial thrombosis in the early postoperative course. Immediate laparatomy with thrombectomy resulted in good, palpable pulsation in the graft artery in both patients. Intraoperative flow measurement demonstrated satisfactory arterial flow in one patient, whereas there was no net flow in the other patient's graft artery. Pulsation in this patient was caused by blood oscillating in and out of the liver. In conclusion, we find that causes of primary graft dysfunction due to technically flawed reperfusion of the graft can be identified and alleviated by intraoperative measurement of the flow in the graft vessels.     

Intraoperative measurement of graft blood flow — a necessity in liver transplantation

Portal venous and hepatic arterial flow was measured intraoperatively in the 70 most recent patients undergoing liver transplantation in our institution. Impaired graft flow due to vascular abnormalities was detected in six patients. One patient suffered from arterial steal due to stenosis of the recipient celiac trunk with blood shunting from the hepatic to the splenic artery. Ligation of the recipient hepatic artery restored the arterial graft flow. In two patients we found reduced portal venous flow due to large portosystemic collaterals. The collaterals accountable for the impaired portal flow were identified and ligated, which restored portal venous graft flow. Excessive sensitivity of the portal venous flow to the position of the graft was found in a 6-month-old boy. Portal venous flow varied considerably, depending upon the position of the graft, and intraoperative flow measurement allowed the best position of the graft to be identified. Two patients developed arterial thrombosis in the early postoperative course. Immediate laparatomy with thrombectomy resulted in good, palpable pulsation in the graft artery in both patients. Intraoperative flow measurement demonstrated satisfactory arterial flow in one patient, whereas there was no net flow in the other patient's graft artery. Pulsation in this patient was caused by blood oscillating in and out of the liver. In conclusion, we find that causes of primary graft dysfunction due to technically flawed reperfusion of the graft can be identified and alleviated by intraoperative measurement of the flow in the graft vessels.     

Early and late results of fresh autologous pericardial valved conduits

The objective of this study was to evaluate the early and late results of an autologous pericardial valved conduit in the pulmonary circulation. Between 1983 and 1997, 86 autologous pericardial valved conduits were used to achieve venous ventricle-pulmonary artery continuity. The mean patient age at the time of implantation was 4.16 ± 4.10 years (15 days to 24 years). All patients had two-dimensional postoperative and yearly Doppler echocardiograms in which the valve function and the presence of distal, valvar, and proximal stenosis were evaluated. There were 13 early deaths (15%). Twenty-one patients (24.4%) showed trivial, 54 (62.8%) mild, nine (10.4%) moderate, and two (2.3%) severe pulmonary regurgitation in the early postoperative period. The 73 survivors were monitored from 1 to 15 years (mean, 6.5 years; median, 7.1 years). There were five late deaths. The mean conduit diameter at the time of implantation was 15.8 mm, increasing to 18.21 mm at last evaluation (P < .0001). There were nine reoperations, with only one conduit replacement. Freedom from reintervention at 5 and 10 years was 89% and 80%, respectively. In conclusion, autologous pericardial valved conduits provide good early and excellent long-term results that compare favorably with those of other conduits. Copyright © 1999 by W.B. Saunders Company     

Pericardial tissue valves and Gore-Tex conduits as an alternative for right ventricular outflow tract replacement in children

BACKGROUND: There is still no perfect conduit for reconstruction of the right ventricular outflow tract (RVOT) in children. Homografts are not always available in the appropriate size, and degenerate in a few years. This study evaluates the pericardial valve with Gore-Tex conduit as an alternative for RVOT construction. METHODS: From January 1, 1993, to September 30, 1999, a pericardial tissue valve was inserted in all patients undergoing RVOT reconstruction or pulmonary valve replacement (PVR) who were large enough to accommodate a tissue valve. In patients without a native main pulmonary artery, a new technique was used to construct an RV-PA conduit out of a flat sheet of Gore-Tex, as Dacron frequently leads to stenosis. Data were collected by retrospective review, follow-up echocardiograms, and assessment by a single cardiologist. RESULTS: There were 48 patients, 22 undergoing a PVR alone and 26 a RV-PA valved Gore-Tex conduit. Diagnosis included tetralogy of Fallot (n = 25); truncus arteriosis (n = 9); ventricular septal defect with PA (n = 5); DORV (n = 4); D-TGA with PS (n = 2); and 1 each IAA with sub AS, VSD with PI, and PS s/p Ross procedure. Patient age ranged from 3 to 33 years and 98% were reoperations. The valve sizes ranged from 19 to 33 mm and the median hospital length of stay was 4 days. There were 2 (4.2%) perioperative and 1 (2.1%) late deaths, none related to the valve or Gore-Tex conduit. At a follow-up of 15 to 86 months (mean 43 +/- 16 months), all remaining 45 patients are New York Heart Association class I, all valves are functional, and no patient has required valve or conduit replacement or revision; more importantly, echocardiogram revealed no significant valve or conduit stenosis (mean gradient 16 +/- 8 mm Hg) and no evidence of regurgitation or structural degeneration. CONCLUSIONS: A pericardial tissue valve and Gore-Tex conduit provides a reliable alternative for RVOT reconstruction in pediatric patients. It is readily available, molds in the limited retrosternal space, and has outstanding intermediate results with no evidence of failure or deterioration up to 7 years after insertion.     

Fluid dynamic comparison of intra-atrial and extracardiac total cavopulmonary connections

OBJECTIVE: Extracardiac total cavopulmonary connection has recently been introduced as an alternative to intra-atrial procedures. The purpose of this study was to compare the hydrodynamic efficiency of extracardiac and intra-atrial lateral tunnel procedures in total cavopulmonary connections. METHODS: Intra-atrial lateral tunnel, extracardiac tunnel, and extracardiac conduit with and without caval vein offset were performed on explanted sheep heart preparations and studied in an in vitro flow loop. A rate of fluid-energy dissipation analysis was performed for each model using simultaneous measurement of pressure and flow at each inlet and outlet of the right side of the heart. Preparations were perfused by using a steady flow blood pump at 4 flow indices (1-6 L/min/m 2) with the inferior vena cava carrying 65% of the total venous return. RESULTS: Fluid-power losses were consistently lower for the extracardiac conduit procedure compared with the two tunnel configurations (P <.01). A further reduction in energy dissipation of up to 36% was noted in the extracardiac procedure, with 5 mm offset of the extracardiac conduit toward the distal right pulmonary. The intra-atrial and extracardiac tunnel procedures were least efficient, with losses 73% greater than the optimal extracardiac conduit procedure. CONCLUSIONS: The extracardiac conduit procedure provides superior hemodynamics compared with the intra-atrial lateral tunnel and extracardiac tunnel techniques. This hydrodynamic advantage is markedly enhanced by the use of conduit-superior vena cava offset, particularly at high physiologic flows that are representative of exercise. These data suggest additional rationale for the use of extracardiac conduit procedures for final-stage completion of the Fontan circulation.     

New approach to the surgical management of pulmonary arteriovenous malformations after cavopulmonary anastomosis

The development of pulmonary arteriovenous malformations after cavopulmonary bypass in patients with congenital heart disease is well documented. We report successful management of pulmonary arteriovenous malformations after cavopulmonary bypass in a patient with an interrupted inferior vena cava (IVC) and multiple hepatic veins utilizing an extracardiac conduit from the hepatic veins to the hemiazygous continuation of the interrupted IVC. This technique, performed without circulatory arrest or an atriotomy, may limit morbidity associated with intracardiac procedures in patients with single ventricle morphology. Furthermore, this case suggests an alternative technique for completion Fontan in patients with an interrupted IVC and multiple hepatic venous drainage.     

The somatic growth of autologous vessels in venous pathway after extracardiac total cavopulmonary connection

Abstract   Objective: In a total cavopulmonary connection (TCPC) with an extracardiac conduit, the future development of stenosis in the venous pathway and distortion of the pulmonary artery according to the somatic growth of the patients is a major concern for surgeons and pediatricians. Methods: Thirty patients who underwent extracardiac TCPC (EC-TCPC) between 1990 and 1998 and who had received at least two postoperative angiograms were enrolled in this study. To evaluate the postoperative change in the anastomosis, the cross-sectional area of the venous root at three different points was measured on the first and second angiograms after the EC-TCPC. Further, to evaluate the somatic growth of the autologous tissue, 12 patients who grew more than 10 cm in height after the completion of the EC-TCPC were selected among the 30 patients. We measured the length of three different parts, the diameter of the pulmonary artery, length of the artificial graft, and length between the branching point of the hepatic vein and artificial graft's anastomotic site to the inferior vena cava. Results: The cross-sectional area at each point did not change during the follow-up, and the pressure gradient across the grafts has not been observed. The diameter of the pulmonary artery and length of the inferior vena cava above the hepatic vein insertion grew similarly during the follow-up. Conclusions: The mid-term clinical results after the completion of the EC-TCPC, including the somatic growth of the venous pathway, were satisfactory. (246 words)     

Autologous tissue-fragmented extracardiac conduit with rapid, stable endothelialization due to angiogenesis.

OBJECTIVES: Autologous angiogenic cytokines are known to activated by mincing stimulation, and well regulated in vivo. We applied this tissue fragmentation technique to a low-pressure pulmonary extracardiac conduit to obtain rapid endothelialization and stable neointima formation due to angiogenesis. METHODS: Subcutaneous adipose tissue was obtained, minced, suspended, and sieved through highly porous fabric vascular prosthesis by pressurized injection. The adipose tissue fragmented graft with an autologous fresh pericardial monocusp valve was implanted between the right ventricle and the pulmonary artery in 13 dogs. The same grafts without fragments were implanted in 8 dogs as controls. No anticoagulation therapy was given. RESULTS: Grafts were removed 6 to 1,128 days after implantation. In the developed grafts, angiogenesis occurred throughout the interstices of the graft wall from the adventitial side, and host cells proliferated and migrated. Endothelialization was completed throughout developed grafts at 2 weeks. The intima was still thin up to 1,128 days and free of degenerative changes. In control grafts, however, capillary infiltration was limited to perigraft tissue at 2 weeks and endothelialization was not completed by 3 months. Under the endothelial cell layer, laminal elastic fibers were formed through the developed graft wall by 4 months and still maintained at 1,128 days. CONCLUSIONS: The results demonstrated that adipose tissue fragmented extracardiac conduits induce rapid endothelialization and maintained thin intima with laminal elastic fibers. Long-term durability is expected based on results from using this technique in a low-pressure pulmonary system in dogs.     

Optimal conduit size for extracardiac Fontan operation

Background: Lack of conduit growth potential and thrombogenicity are the main drawbacks of the extracardiac Fontan operation (ECFO). Optimal size of the conduit according to the patients age and inferior vena cava diameter has not been established. Objectives: We set out to ascertain whether the optimal dimensions of the conduit could be determined before an ECFO. Methods: Actual and expected age-related inferior vena cava diameters were compared with the extracardiac conduit diameter in 20 patients after ECFO. In 50 other pediatric and adult patients, the distance between intrapericardial part of the inferior vena cava and the undersurface of the right pulmonary artery (IVC–RPA) was measured. Cases of conduit thrombosis were analyzed. Results: The actual diameter of the inferior vena cava was variable and has a weak correlation with anthropmetric data and expected diameter (R=0.07–0.23, P=0.32–0.76). The IVC–RPA distance correlated with height (R=0.87, P=0.0001), but was also variable. At the age of 2–4 years and body weight 12–15 kg IVC diameter and IVC–RPA distance are equal to 60–80% of adult values. Conduit thrombosis developed in two patients with unfavorable Fontan hemodynamics and oversized conduits. Conclusions: Considering the inferior vena cava size, ECFO may be performed at the age of 2–3 years and at a body weight 12–15 kg, when a hemodynamically optimal almost adult sized conduit can be implanted. Optimization of the conduit is necessary on the basis of the actual inferior vena cava diameter and IVC–RPA distance. Anticoagulation postoperatively should be considered to prevent conduit thrombosis in patients with suboptimal Fontan circulation     

Bovine valved xenograft (Contegra) conduit in the extracardiac Fontan procedure: the preliminary experience

OBJECTIVE: Constructing a competent valve using the xenograft valved conduit (Contegra) in the extracardiac Fontan connection may maintain better forward flow into the pulmonary circulation. The preliminary results and potential advantages of using the Contegra are discussed in this review. METHOD: A retrospective review of 18 patients who underwent the extracardiac Fontan connection using the Contegra conduit from June 2002 to September 2005. RESULTS: Median age at the time of operation was 4.5 year (range 2.5-34 years). In 15 patients (83%) a 4 mm fenestration was created. Overall operative mortality was 11 % (two patients); one patient died because of arrhythmia & sepsis, and the other one due to thrombosed Fontan connection. The ranges of intensive care unit stay, chest tube duration, and hospital stay were 1-18 days (median, 2 days), 4-38 days (median, 7 days), and 5-47 days (median, 12.5 days), respectively. Follow-up is available for 15 (94%) patients at a mean of 15.8 months (range 8-48 months) postoperatively. They were all asymptomatic and their room air oxygen saturation ranged between 88% and 100% (mean, 96.1%). There have been no further thromboembolic episodes during follow up. Echocardiograms demonstrated patent conduit in all patients with no hepatic vein reversal flow except to a minimal degree in five patients; however the valve competency was demonstrated radiologically. CONCLUSIONS: The Contegra xenograft is a potential alternative conduit for the extracardiac Fontan connections. These encouraging preliminary results may support better pulmonary forward flow.     

Pedicled pericardial flap for pulmonary artery in adult dogs.

OBJECTIVE: Stenosis of extracardiac conduit after reconstruction of right ventricle outflow tract is a serious problem, and the purpose of this study was to identify the suitability of broadly pedicled autologous pericardial flap for the reconstruction of pulmonary artery trunk in adult dogs. METHODS: Eight mongrel dogs had replacement of a pulmonary artery trunk with extracardiac conduit, in which prosthetic vascular graft formed the posterior wall and pedicled (group P, n = 5) or free (group F, n = 3) autologous pericardium created the anterior wall. Six months after the operation, pressure gradient across the conduit were measured and put to death for pathological examinations. RESULTS: Pressure gradient across the conduit in groups F and P was 16.0 +/- 16.8 mmHg and 1.4 +/- 1.7 mmHg respectively. In the microscopic examination, flaps of group P had neo-intimal cells in the innermost layer, abundant cellular component with elastic fiber was seen within the middle layer, and collagen tissue within the outer layer. Conversely, the presence of calcification was shown within collagen fiber layer of all patches in group F. Sparse cellular component and the absence of neo-intimal cells were also observed in group F. CONCLUSIONS: Broadly pedicled pericardial flap is more conceivable to prevent the development of conduit stenosis after right ventricle outflow tract reconstruction, if compared with free pericardial patches.     

Long-term outcome of right ventricular outflow tract reconstruction using a handmade tri-leaflet conduit.

OBJECTIVE: Since 1985, we have implanted handmade tri-leaflet conduits made of heterologous pericardium or expanded polytetrafluoroethylene (ePTFE), as an alternative to homograft for right ventricular outflow tract reconstruction. This report assesses the long-term outcome of these prostheses. METHODS: From 1985 to 2003, 216 handmade tri-leaflet conduits were implanted in 191 patients. Forty-two patients had previous conduit repairs. The mean age at operation was 8.1+/-7.7 years (range: 15 days-44 years). The underlying diagnoses were pulmonary atresia with ventricular septal defect in 83 patients, atrioventricular discordance in 36, transposition of the great arteries in 26, double outlet right ventricle in 14, and truncus arteriosus in 17. Whole heterologous pericardial tri-leaflet conduits were implanted in 169 patients, in the early series (porcine: 85; equine: 58; bovine: 26); bovine pericardial conduits containing ePTFE leaflets were implanted in 26 patients since 1996; whole ePTFE tri-leaflet rolls were employed in the most recent 21 patients. The conduit size was 21.1+/-3.1mm (range: 12-27 mm), 147.4+/-21.4% (range: 82.6-202.6%) of the anticipated diameter of the pulmonary valve. Follow-up was complete. RESULTS: There were 28 early deaths and 24 late deaths. The indication for conduit replacement was a peak instantaneous pressure gradient of greater than 50 mmHg. Sixty-five conduits required reoperation for conduit obstruction at 8.6+/-3.3 years after implantation. The freedom from reoperation at 5, 10, and 15 years was 93.9+/-1.9, 61.4+/-4.5, and 35.5+/-5.6%, respectively. Patients with smaller conduit size and young age at operation were predisposed to reoperation. None of the 47 ePTFE tri-leaflet conduits developed significant obstruction. The freedom from important pulmonary valve regurgitation (PR) as assessed by echocardiography was 68.3+/-3.7% at 5 years, 33.0+/-4.5% at 10 years, and 21.6+/-4.9% at 15 years. No patient required reoperation due to PR or right ventricular dysfunction. CONCLUSIONS: Handmade tri-leaflet conduits provide a reliable alternative for RVOT reconstruction in children, yielding as good a long-term outcome as do homografts. Longer follow-up is needed to determine how well ePTFE leaflets will fare.     

Modified Fontan operation for a single ventricle with a nonconfluent pulmonary artery]

A 8-year-old boy with a double inlet right ventricle with a non-confluent pulmonary artery was operated on with a modified Fontan operation. He had right isomerism, right aortic arch, bilateral superior caval veins, and left-sided inferior caval vein. Hepatic veins were separately drained to the right-side atrium. Left Blalock-Taussig shunt and right central shunt operations had been previously performed. Firstly, we had reconstructed the central pulmonary artery with a 16 mm porcine pericardial roll to unify the nonconfluent pulmonary arteries. Secondly, about 2 months after the first operation, we performed a modified Fontan operation. Systemic venous return from the inferior caval vein and the hepatic veins were drained to a reconstructed pericardial roll with an intraatrial Gore-Tex graft, and bilateral superior caval veins were also anastomosed to the roll. The structure of the pulmonary arterial system is one of the most important factors to determine the outcome of a modified Fontan operation. Even if the central pulmonary artery is absent, however, a modified Fontan operation is applicable for the patient whose peripheral pulmonary arteries have enough growth.