Right ventricle to pulmonary artery conduit: a comparison of long-term graft-related events between bovine jugular vein conduit, aortic homograft, and porcine-valved conduits.

Background: The optimal conduit for right ventricle to pulmonary artery (RV-PA) reconstruction does not exist. Reinterventions are common due to conduit stenosis and endocarditis. Tailoring conduit choice according to patients' characteristics could improve the outcomes. The study aimed to compare graft-related events (infective endocarditis, transcatheter pulmonary valve replacement (PVR), transcatheter conduit dilatation, surgical conduit replacement, and transcatheter pulmonary branch intervention for RV-PA reconstruction using bovine jugular vein, aortic homograft, and porcine-valved conduits. Methods: In a retrospective cohort study, 155 patients with 193 procedures that were done in King Faisal Specialist Hospital and Research Center-Jeddah (KFSHRC JED) for implanting RV-PA conduits from 1999 to 2021 were included. The patients were grouped according to the type of conduit into 3 groups; Group 1 (n=153) received bovine jugular vein (BJVs) grafts, Group 2 (n=29) received aortic homografts, Group 3 (n=11) received porcine-valved conduits. Factors associated with graft-related events were evaluated using stepwise Cox regression analysis. Results: Patients with BJVs were significantly younger than those with porcine-valved conduits 3 (P=0.009). The weight of BJVs patients was significantly lower than homografts (P=0.002) and porcine-valved conduits patients 3 (P<0.001). The conduit size was as expected significantly lower in BJVs patients than patients who received porcine-valved conduits (P<0.001) and patients who received aortic homografts (P<0.001). There was no difference between Group 2 and 3 (P=0.084). Operative mortality occurred in 13 patients: 12 (7.84%) with BJV conduit and 1 (9.09%) with porcine valved conduit (P=0.351). Male gender [odds ratio (OR): 10.04; 95% confidence interval (CI): 1.28-78.86; P=0.028] and smaller conduit size (OR: 0.78; 95% CI: 0.61-0.99; P=0.048) were associated with increased operative mortality. Freedom from graft-related events at 5 and 10 years was 67% and 52% in BJVs patients, 74% and 36% in patients who received aortic homografts, and 53% in patients who received porcine-valved conduits. Factors associated with increased graft-related events were male gender (HR: 1.58; 95% CI: 1.004-2.50, P=0.048) and younger age (HR: 0.995; 95% CI: 0.991-0.999, P=0.041). Conclusions: RV-PA reconstruction was associated with low mortality, unrelated to the conduit type. Reinterventions for graft-related events were common. The durability and graft-related events might be comparable among BJV grafts, aortic homografts, and porcine-valved conduits. Factors associated with increased graft-related events in this study were male gender and younger age.

Epoxy- versus Glutaraldehyde-Treated Bovine Jugular Vein Conduit for Pulmonary Valve Replacement: A Comparison of Morphological Changes in a Pig Model.

Valved conduits are often required to replace pulmonary arteries (PA). A widely used Contegra device is made of bovine jugular vein (BJV), preserved with glutaraldehyde (GA) and iso-propanol. However, it has several drawbacks that may be attributed to its chemical treatment. We hypothesized that the use of an alternative preservation compound may significantly improve BJV conduit performance. This study aimed to compare the macroscopic and microscopic properties of the BJV treated with diepoxide (DE) and GA in a porcine model. Twelve DE-BJVs and four Contegra conduits were used for PA replacement in minipigs. To assess the isolated influence of GA, we included an additional control group-BJV treated with 0.625% GA (n = 4). The animals were withdrawn after 6 months of follow-up and the conduits were examined. Explanted DE-BJV had a soft elastic wall with no signs of thrombosis or calcification and good conduit integration, including myofibroblast germination, an ingrowth of soft connective tissue formations and remarkable neoangiogenesis. The inner surface of DE-BJVs was covered by a thin neointimal layer with a solid endothelium. Contegra grafts had a stiffer wall with thrombosis on the leaflets. Calcified foci, chondroid metaplasia, and hyalinosis were observed within the wall. The distal anastomotic sites had hyperplastic neointima, partially covered with the endothelium. The wall of GA-BJV was stiff and rigid with degenerative changes, a substantial amount of calcium deposits and dense fibrotic formations in adventitia. An irregular neointimal layer was presented in the anastomotic sites without endothelial cover in the GA BJV wall. These results demonstrate that DE treatment improves conduit integration and the endothelialization of the inner surface while preventing the mineralization of the BJV, which may reduce the risk of early conduit dysfunction.

Pentagalloyl glucose-stabilized decellularized bovine jugular vein valved conduits as pulmonary conduit replacement.

Congenital heart diseases (CHD) are one of the most frequently diagnosed congenital disorders, affecting approximately 40,000 live births annually in the United States. Out of the new patients diagnosed with CHD yearly, an estimated 2,500 patients require a substitute, non-native conduit artery to replace structures congenitally absent or hypoplastic. Devices used for conduit replacement encounter limitations exhibiting varying degrees of stiffness, calcification, susceptibility to infection, thrombosis, and a lack of implant growth capacity. Here, we report the functionality of pentagalloyl glucose (PGG) stabilized decellularized valved bovine jugular vein conduit (PGG-DBJVC). The PGG-DBJVC tissues demonstrated mechanical properties comparable to native and glutaraldehyde fixed tissues, while exhibiting resistance to both collagenase and elastase enzymatic degradation. Subcutaneous implantation of tissues established their biocompatibility and resistance to calcification, while implantation in sheep in the pulmonary position demonstrated adequate implant functionality, and repopulation of host cells, without excessive inflammation. In conclusion, this PGG-DBJVC device could be a favorable replacement option for pediatric patients, reducing the need for reoperations required with current devices. STATEMENT OF SIGNIFICANCE: Congenital Heart Disease (CHD) is a common congenital disorder affecting many newborns in the United States each year. The use of substitute conduit arteries is necessary for some patients with CHD who have missing or underdeveloped structures. Current conduit replacement devices have limitations, including stiffness, susceptibility to infection and thrombosis, and lack of implant growth capacity. Pentagalloyl glucose-stabilized bovine jugular vein valved tissue (PGG-DBJVC) offers a promising solution as it is resistant to calcification, and biocompatible. When implanted in rats and as pulmonary conduit replacement in sheep, the PGG-DBJVC demonstrated cellular infiltration without excessive inflammation, which could lead to remodeling and integration with host tissue and eliminate the need for replacement as the child grows.

Long-Term Follow-Up of Right Ventricle to Pulmonary Artery Biologic Valved Conduits Used in Pediatric Congenital Heart Surgery.

Valved conduit reconstruction between the right ventricle (RV) and the pulmonary circulation is often necessary in the surgical treatment of complex congenital heart defects. The aim of this study is to evaluate the long-term performance of the three types of conduits we have used and assess risk factors for conduit failure. Retrospective, single-center review of 455 consecutive pediatric patients with 625 conduits from 1990 to 2019 undergoing RV-to-pulmonary artery (PA) reconstruction with a valved conduit. The three conduit types investigated were pulmonary homograft, aorta homograft, and bovine jugular vein (BJV) graft. Overall patient survival was 91.4%, freedom from conduit replacement (FCR) was 47.4%, and freedom from reintervention (FFR) was 37.8% with a median follow-up of 8.7 years (interquartile range 4.3-13.3 years). For pulmonary homografts, 10-, 20-, and 28-year FCR was 79.6%, 68.6%, and 66.0%, respectively. For aortic homografts, 10-, 20-, and 30-year FCR was 49.8%, 31.5%, and 23.0%, respectively. For BJV grafts, 10- and 19-year FCR was 68.1% and 46.0%, respectively. When controlling for baseline variables, FCR was similar for pulmonary homografts and BJV grafts. Overall patient survival was excellent. Risk factors for conduit failure in patients operated with reconstruction of the RV-PA outflow tract included low age, low weight, small conduit size, and certain cardiac diagnoses. There was no evidence for a shorter life span of the second graft. Pulmonary homografts and BJV grafts performed similarly but the risk of endocarditis was greater in the BJV group.

Decellularized bovine jugular vein and hand-sewn ePTFE valved conduit for right ventricular outflow tract reconstruction in children undergoing Ross procedure.

Background: The Ross procedure is recommended as an optimal aortic valve replacement (AVR) in children and young adults due to several advantages. Nevertheless, multiple reconstructions of the right ventricular outflow tract (RVOT) with new valve conduits have caused some concern regarding the durability of the Ross AVR. Decellularized bovine jugular vein conduit (BJVC) (DP-BJVC) and hand-sewn expanded polytetrafluoroethylene valved conduits (ePTFE VC) are widely employed to reconstruct the RVOT with satisfactory long-term outcomes. However, few studies have compared the safety and efficacy between the two valve conduits. We aimed to evaluate the early outcomes and report our single center experience in the application of these conduits. Methods: Twenty-two pediatric patients (aged < 18 years) who underwent Ross procedures with DP-BJVC and ePTFE VC in our center between 1 June, 2017 and 31 January, 2022 were enrolled. The Kaplan-Meier method was used to evaluate survival, freedom from RVOT reintervention, and freedom from RVOT graft dysfunction. Mixed-effects analysis with the Geisser-Greenhouse correction and Sidak's multiple comparisons test for post-hoc analysis was employed to compare the peak gradient across the conduit at varying follow-ups. Results: All patients were followed up in full. The total early survival rate was 90.9%; two patients in the DP-BJVC group died. There was no significant difference in early mortality, cross-clamp time (p = 0.212), in-hospital stay (p = 0.469), and RVOT graft thrombosis or endocarditis between the two groups. There was similarly no significant difference between Kaplan-Meier freedom from RVOT graft dysfunction curve (P = 0.131). The transprosthetic gradient gradually increased over time in both groups and was significantly higher in the DP-BJVC group at follow-up (P < 0.05). Conclusions: Both conduits show excellent early and midterm outcomes for RVOT reconstruction in the Ross procedure. We suggest that DP-BJVC is more suitable for infants, and ePTFE conduit is more suitable for older children who require larger conduits.

Current development of bovine jugular vein conduit for right ventricular outflow tract reconstruction.

Right ventricular outflow tract (RVOT) reconstruction is a common surgical method to treat congenital cardiac lesions, and bovine jugular vein conduit (BJVC) has become a prevalent candidate of prosthetic material for this procedure since 1999. Although many clinical studies have shown encouraging results on BJVCs, complications such as stenosis, aneurysmal dilatation, valve insufficiency, and infective endocarditis revealed in other clinical outcomes still remain problematic. This review describes the underlying mechanisms causing respective complications, and summarizes the current technological development that may address those causative factors. Novel crosslinking agents, decellularization techniques, conduit coatings, and physical reinforcement materials have improved the performances of BJVCs. The authors expect that the breakthroughs in the clinical application of BJVC may come from new genetic research findings and advanced characterization apparatuses and bioreactors, and are optimistic that the BJVC will in the future provide sophisticated therapies for next-generation RVOT reconstruction.

Risk factors for early adverse outcomes after bovine jugular vein conduit implantation: influence of oversized conduit on the outcomes.

OBJECTIVES: We investigated potential risk factors for early failure of bovine jugular vein conduit (Contegra®) implantation for right ventricular outflow tract (RVOT) reconstruction. METHODS: A single-centre retrospective review of 115 consecutive patients (54 males) who underwent RVOT reconstruction with Contegra between 2016 and 2019 was performed. Overall survival, explantation-free survival and freedom from significant RVOT lesions (valve regurgitation ≥ moderate or flow velocity ≥3.5 m/s) were investigated. RESULTS: Median age, body weight and Contegra diameter were 10.3 months [interquartile range (IQR) 5.7-26.9 months], 7.8 kg (IQR 6.3-12.4 kg) and 14 mm (IQR 12-16 mm), respectively. During the median follow-up duration of 25.1 months, there were 7 deaths, 34 significant RVOT lesions, 10 endocarditis episodes and 15 explantations. Overall survival and explantation-free survival at 3 years were 94.8% and 78.4%, respectively. Significant RVOT lesions (n = 34) comprised 20 stenoses, 8 regurgitations and 6 combined lesions. Freedom from significant RVOT lesions at 3 years was 62.6%. Cox regression identified higher indexed Contegra size (Contegra diameter/body weight, mm/kg) as the only risk factor for decreased time to explantation or death (hazard ratio 2.32, P < 0.001) and time to significant RVOT lesions development (hazard ratio 2.75, P < 0.001). The cut-off value of indexed Contegra size for significant RVOT lesions at 12 months was 1.905 mm/kg (sensitivity, 0.75; specificity, 0.78; area under the curve, 0.82). CONCLUSIONS: Outcomes of RVOT reconstruction using Contegra were acceptable. However, oversized Contegra should be avoided when possible. IRB APPROVAL DATE: 26 October 2020. IRB REGISTRATION NUMBER: S2020-2505-0001.

Individualized right ventricular outflow tract reconstruction using autologous pulmonary tissue in situ for the treatment of pulmonary atresia with ventricular septum defect.

OBJECTIVE: The study aims to evaluate the feasibility and effectiveness of an individualized procedure for right ventricular outflow tract (RVOT) reconstruction in pulmonary atresia with ventricular septal defect (PA-VSD). METHODS: RVOT was reconstructed using autologous pulmonary artery tissue preserved in situ as the posterior wall and a bovine jugular vein patch (BJVP) as the anterior wall in patients with PA-VSD (observation group). The size of the BJVP made from a bovine jugular vein conduit (BJVC) was individually calculated using a formula based on the child's weight and the size of the autologous pulmonary artery (the diameter of BJVC DB⁢J⁢V⁢C = Dt⁢h⁢e⁢o⁢r⁢e⁢t⁢i⁢c⁢a⁢l-W⁢z^-4π). Its effect was then compared with the conventional modified Rastelli procedure based on the BJVC (control group). RESULTS: A total of 22 patients that underwent the new procedure were simultaneously compared with the 25 patients in the control group. No deaths occurred in both groups. Notably, there were no significant differences in mechanical ventilation, ICU and postoperative residence, cardiopulmonary bypass, and aortic cross-clamp time. In the follow-up, which spanned for 8-12 years (mean 9.2 years), only four cases with moderate regurgitation were noted in the observation group without obstruction. In the control group, two patients had a conduit replacement. Three patients suffered from anastomotic stenosis, which was corrected by balloon dilatation. CONCLUSION: Individualized RVOT reconstruction with autologous pulmonary tissue preserved in situ as the posterior wall is adequate for treating PA-VSD.

Comparison of homografts and bovine jugular vein conduits in the pulmonary position in patients <20 years of age.

OBJECTIVE: To compare the performance of homografts and bovine jugular vein (BJV) conduits in the pulmonary position. METHODS: All patients with congenital heart disease up to age 20 years who underwent pulmonary valve replacement with homografts or BJV at 3 centers in Australia were evaluated. There were 674 conduits, with 305 (45%) pulmonary homografts (PHs), 303 (45%) BJV conduits, and 66 (10%) aortic homografts (AHs). Endpoints were freedom from reintervention, structural valve degeneration (SVD), and infective endocarditis (IE). Propensity score matching was used to balance the comparison of PH and BJV conduits. RESULTS: The median follow-up was 6.4 years (interquartile range, IQR, 3.1-10.7 years). Freedom from reintervention at 5 and 10 years was 92% and 80%, respectively, for PH, 74% and 37% for BJV, and 75% and 47% for AH. BJV conduits had a higher risk of reintervention (P < .001) and SVD (P < .001) compared with PHs. These findings were confirmed with propensity score matching valid for conduit size >15 mm. AHs >15 mm had a higher risk of reintervention (P < .001) and SVD (P < .001) compared with PHs >15 mm. The performance of AHs and BJV conduits was similar across all sizes (reintervention, P = .94; SVD, P = .72). The incidence of IE was 1% for PH, 10% for BJV, and 1.5% for AH. CONCLUSIONS: In patients age <20 years with a conduit >15 mm, PHs outperformed BJV conduits and AHs in the pulmonary position. The performance of AH and BJV was comparable. Small conduits (≤15 mm) had similar performance across all conduit types.

Bovine jugular vein conduit: What affects its elastomechanical properties and thermostability?

The aim of this study was to compare the mechanical properties and thermal stability of the venous wall depending on the treatment method used, and, accordingly, on those structural changes in the tissue that this treatment causes. Bovine jugular vein walls (BJVWs) cross-linked with glutaraldehyde (GA), ethylene glycol diglycidyl ether (DE), and Contegra commercial conduit were evaluated using uniaxial stretching [with and without pre-conditioning (PreC)], differential scanning calorimetry, amino acid analysis, and attenuated total reflection infrared spectroscopy. Fresh BJVW was used as a control. It was shown that failure stress in non-PreC GA-treated and DE-treated materials was lower than that in fresh and Contegra counterparts. Contegra samples were the stiffest among the tested materials. Cyclic preloading leads to distortion of the mechanical behavior of this material, which is heterogeneous in composition and structure. The denaturation temperatures (Td ) of all cross-linked BJVWs were higher than the Td of the fresh vein. The microstructures of the tested BJVWs did not exhibit any differences, but the cross-linking density and hydration of the DE-vein were the highest. GA-cross-linking or DE-cross-linking and isopropanol exposure (Contegra) changed the protein secondary structures of the tested materials in different ways. We hypothesized that the protein secondary structure and hydration degree are the main causes of differences in the mechanical properties and thermal stability of BJVW.

Conduits for Right Ventricular Outflow Tract Reconstruction in Infants and Young Children.

Purpose of Review: Right ventricular outflow tract (RVOT) reconstruction remains a challenge due to the lack of an ideal conduit. Data and experience are accumulating with each passing day. Therefore, it is necessary to review this topic from time to time. This is a 2021 update review focused on the history, evolution, and current situation of small-sized conduits (≤ 16 mm) for RVOT reconstruction in infants and young children. Recent Findings: Currently, the available small-sized (≤16 mm) conduits can meet most clinical needs. Homograft is still a reliable choice for infants and young children validated by a half-century clinical experience. As an alternative material, bovine jugular vein conduit (BJVC) has at least comparable durability with that of homograft. The performance of expanded polytetrafluoroethylene (ePTFE) is amazing in RVOT position according to limited published data. The past century has witnessed much progress in the materials for RVOT reconstruction. However, lack of growth potential is the dilemma for small-sized conduits. Tissue-engineering based on cell-free scaffolds is the most promising technology to obtain the ideal conduit. Summary: No conduit has proved to have lifelong durability in RVOT position. We are far from the ideal, but we are not in a state of emergency. In-depth clinical research as well as innovation in material science are needed to help improve the durability of the conduits used in infants and young children.

Midterm Outcomes of Crosslinked Acellular Bovine Jugular Vein Conduit for Right Ventricular Outflow Tract Reconstruction.

Objectives: Conduits for reconstructing right ventricular outflow tract (RVOT) in children with congenital heart disease have evolved for better durability over the past decades, but conduits failure remains common. We designed decellularized and photooxidatively crosslinked bovine jugular vein conduit (DP-BJVC) and now aim to evaluate the midterm results of DP-BJVC for RVOT reconstruction. Methods: Ninety patients (median age: 4.2 years) undergoing RVOT reconstruction using DP-BJVC were prospectively followed for median of 4.7 years (range: 0.2-16.1 years). Kaplan-Meier analysis was used to examine the survival, freedom from conduit explantation and catheter-based reintervention. Risk factors were analyzed with Cox regression analysis. Results: Follow-up was completed in 92% of patients. There were five (5.6%) early deaths. The 10-year survival rate was 85.2%, with palliative procedure at DP-BJVC implantation as the risk factor. The 10-year freedom from conduit explantation and reintervention were 84.4 and 67.3% respectively, with previous cardiac operation as the only risk factor for explantation. Complications during the follow-up included conduit stenosis (peak gradient ≥50 mmHg) in 12 (12.9%), severe regurgitation in 2 (2.4%), and infective endocarditis in 2 (2.4%). The annual increase in gradient was highest in the first year (P = 0.003), but not appreciably afterwards. The echo-measured annulus diameter trends to increase by an average of 0.37 mm per year. Calcification appeared mild in the failed conduits. Conclusions: DP-BJVC provides satisfactory durability and functionality for RVOT reconstruction for children, with low morbidity of stenosis and endocarditis, as well as increase in diameter mildly with age in midterm follow-ups.

Immobilized Bisphosphonates as Potential Inhibitors of Bioprosthetic Calcification: Effects on Various Xenogeneic Cardiovascular Tissues.

Calcification is the major factor limiting the clinical use of bioprostheses. It may be prevented by the immobilization of bisphosphonic compounds (BPs) on the biomaterial. In this study, we assessed the accumulation and structure of calcium phosphate deposits in collagen-rich bovine pericardium (Pe) and elastin-rich porcine aortic wall (Ao) and bovine jugular vein wall (Ve) cross-linked with glutaraldehyde (GA) or diepoxy compound (DE). These tissues were then modified with pamidronic (PAM) acid or 2-(2'-carboxyethylamino)ethylidene-1,1-bisphosphonic (CEABA) acid. Tissue transformations were studied using Fourier-transform infrared spectroscopy. After subcutaneous implantation of the biomaterials in 220 rats, calcification dynamics were examined using atomic absorption spectrophotometry, light microscopy after von Kossa staining, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy The calcium content in all GA-cross-linked tissues and DE-cross-linked Ao increased to 100-160 mg/g on day 60 after implantation. BPs prevented the accumulation of phosphates on the surface of all materials and most effectively inhibited calcification in GA-cross-linked Ao and DE-cross-linked Pe. PAM containing -OH in the R1 group was more effective than CEABA containing -H in R1. The calcification-inhibitory effect of BPs may be realized through their ability to block nucleation and prevent the growth of hydroxyapatite crystals.

Treatment with bisphosphonates to mitigate calcification of elastin-containing bioprosthetic materials.

This study evaluated the ability of bisphosphonates (BPAs) of different molecular structures to mitigate the calcification of porcine aortic wall (PAW) and bovine jugular vein wall (BJVW). Tissues cross-linked with glutaraldehyde (GA) or diepoxide (DE) were modified with pamidronic acid (PAM), alendronic acid (ALE), neridronic acid (NER) (type 1 BPAs); 2-(2'-carboxyethylamino)ethylidene-1,1-bisphosphonic acid (CEABA), 2-(5-carboxypentylamino)ethylidene-1,1-bisphosphonic acid (CPABA) (type 2); and zoledronic acid (ZOL) (type 3). After implanting the tissue samples subcutaneously in 100 rats, calcification was examined using atomic absorption spectrophotometry (60-day explants) and light microscopy after von Kossa staining (10- and 30-day explants). The calcium contents in GA-BJVW and GA- and DE-PAW increased up to 100-120 mg/g after 60 days, while being 3 times lower in DE-BJVW. In modified and nonmodified PAW samples, calcium phosphates appeared by day 10 and were associated with elastic fibers and devitalized cellular elements. In all groups of BJVW samples, mineralization began in elastic fibers near the subendothelial layer. In addition, calcified collagen was found in the GA-BJVW samples. Minimal calcification was found in GA-PAW treated with type 1 BPAs and CEABA. For DE-PAW and GA-BJVW, the calcium level significantly decreased with PAM and CEABA. Meanwhile, ALE and NER were effective for DE-BJVW.

Bovine jugular vein conduit versus pulmonary homograft in the Ross operation.

OBJECTIVES: The Ross procedure involves using the native pulmonary valve for aortic valve replacement then replacing the pulmonary valve with an allograft or xenograft. We aimed to compare our age-matched experience with the bovine jugular vein conduit and the pulmonary homograft for pulmonary valve replacement during the Ross procedure in children. METHODS: Between 1998 and 2016, 15 patients <18 years of age underwent a Ross procedure using the bovine jugular vein conduit (Ross-Bovine Jugular Vein Conduit) at our institution. These patients were age-matched with 15 patients who had the Ross operation with a standard pulmonary homograft for right ventricular outflow tract reconstruction (Ross-Pulmonary Homograft). Paper and electronic medical records were retrospectively reviewed. RESULTS: The median age of the Ross-Bovine Jugular Vein Conduit and Ross-Pulmonary Homograft patients were 4.8 years (interquartile range 1.1-6.6) and 3.3 years (interquartile 1.2-7.6), respectively (p = 0.6). The median follow-up time for the Ross-Bovine Jugular Vein Conduit and Ross-Pulmonary Homograft groups were 1.7 years (interquartile range 0.5-4.9) and 6.8 years (interquartile range 1.9-13.4), respectively (p = 0.03). Overall, 5-year survival, freedom from redo aortic valve replacement, and freedom from pulmonary valve replacement were similar between groups. CONCLUSION: The bovine jugular vein conduit and pulmonary homograft have favourable mid-term durability when used for right ventricular outflow tract reconstruction for the Ross operation. The bovine jugular vein conduit may be a suitable replacement for appropriately sized patients undergoing a Ross aortic valve replacement, though longer follow-up is needed.

Mid-term outcomes following valved bovine jugular vein conduit versus autologous pericardium conduit for right ventricular outflow tract reconstruction / 第二军医大学学报

Objective To compare the mid-term outcomes of valved bovine jugular vein conduit and autologous pericardium conduit in reconstruction of right ventricular outflow tract. Methods Eighteen congenital heart disease patients were implanted with external conduits (included 11 valved bovine jugular vein conduits and 7 autologous pericardium conduits) for right ventricular outflow tract reconstruction between May 2013 and Jul. 2016. There were 11 males and 7 females at age of 2-16 (5.22±4.12) years. Preoperative clinical diagnoses included pulmonary artery atresia with ventricular septal defect (n＝7), double outlet of right ventricle with pulmonary stenosis (n＝4), persistent truncus arteriosus (n＝3), persistent truncus arteriosus with absence of right pulmonary artery (n＝1), corrected transposition of great arteries with pulmonary stenosis (n＝1), and transposition of great arteries with pulmonary stenosis (n＝2). The perioperative status was recorded. The cardiac ultrasound and computed tomography angiography (CTA) were used to evaluate the efficacy during 4-56 months of follow-up. Results There were no perioperative deaths in the bovine jugular vein conduit group, and 2 deaths in the autologous pericardium conduit group. One died of pulmonary hypertension crisis and the other died of low cardiac output syndrome. The ratio of right ventricular pressure to radial arterial pressure, duration of mechanical ventilation and intensive care unit (ICU) stay after surgery were significantly lower in the bovine jugular vein conduit group than those in the autologous pericardium conduit group (all P0.05). There were no significant differences in extracorporeal circulation time, aortic cross-clamping time, transvalvular gradient in right ventricular outflow tract, blood consumption or total hospitalization costs between the two groups (all P0.05). During follow-up, there were no deaths in the two groups, no reoperations in the bovine jugular vein conduit group, and 1 case received reoperation 2 years after surgery due to severe right ventricular dysfunction in the autologous pericardium conduit group. In the bovine jugular vein conduit group, the transvalvular gradients in right ventricular outflow tract at the last follow-up and before discharge were (22.91±7.31) mmHg (1 mmHg＝0.133 kPa) and (20.45±6.70) mmHg, respectively, and the difference was not significant (P0.05). In the autologous pericardium conduit group, the transvalvular gradient in right ventricular outflow tract was (29.20±18.09) mmHg at the last follow-up and (16.14±4.02) mmHg before discharge, and the difference was significant (P0.05). At the last follow-up after surgery, there were 8 cases of mild reflux and 3 cases of moderate reflux in the bovine jugular vein conduit group, and 1 case of mild reflux, 2 cases of moderate reflux and 2 cases of severe reflux in the autologous pericardium conduit group, and the difference between the two groups was significant (P0.05). Postoperative ultrasonography showed the thickened valve leaflets with good valve movement in the bovine jugular vein conduit. No calcification, thrombosis and infective endocarditis were found in the two groups. Postoperative cardiac CTA found that there was aneurysmal dilatation in 1 middle segment and 1 proximal anastomotic stoma of the bovine jugular vein conduit group, and no dilatation in the autologous pericardium conduit group. Conclusion Domestic valved bovine jugular vein conduit is suitable for right ventricular outflow tract reconstruction in patients with complex congenital heart malformations. Mid-term follow-up shows that bovine jugular vein conduit has good anti-reflux performance and no severe obstruction or calcification. It is obviously superior to autologous pericardium conduit. However, some bovine jugular vein conduits have aneurysmal dilatation in mid-term follow-up, which needs to be further improved.

Surgical outcome after complete repair of tetralogy of Fallot with absent pulmonary valve: comparison between bovine jugular vein-valved conduit and monocusp-valve patch.

BACKGROUND: The prognosis of tetralogy of Fallot with absent pulmonary valve (TOF/APV) without operation is poor. We evaluated the surgical outcome of TOF/APV in a single center. METHODS: Twenty-two TOF/APV patients underwent complete surgical correction in our hospital. Right ventricular outflow tract reconstruction was performed using bovine jugular vein (BJV)-valved conduit implantation (n = 10), homograft-valved conduit implantation (n = 2), or monocusp-valve patch (n = 10). Health-related quality of life (QOL) was evaluated during follow-up. RESULTS: The overall survival at 5 and 10 years was 86.4 ± 7.3% (confidence interval 69.4-97.2%). The survival rates were significantly different between patients with and without bronchial stenosis (40 and 100%, P = 0.0003, log-rank test). The survival of patients aged > 6 months was higher than those ≤ 6 months (100 vs. 40%, P = 0.0003, log-rank test). Patients with BJV-valved conduits had higher systolic gradients from the right ventricle to the pulmonary artery (RV-PA) compared to those with monocusp-valve patches. BJV-valved conduit implantation was a risk factor for post-operative pulmonary-valve stenosis. The QOL score for patients with BJV-valved conduits was lower than those with monocusp-valve patches (P < 0.05). No reoperation was performed during follow-up. CONCLUSIONS: Bronchial stenosis and lower age (≤ 6 months) were the main factors influencing post-operative survival. The use of a BJV-valved conduit was a main reason for RV-PA restenosis; thus, the use of a BJV-valved conduit may increase the need for repeat intervention and decrease the post-operative quality of life.

High incidence of late infective endocarditis in bovine jugular vein valved conduits.

BACKGROUND: Bovine jugular vein (BJV) grafts (Medtronic, Inc, Minneapolis, Minn) are used to restore right ventricle-to-pulmonary artery continuity. Recent studies have associated these grafts with the development of infective endocarditis. The purpose of this study was to report the incidence of endocarditis in BJV grafts. METHODS: All BJV grafts placed in the right ventricle-to-pulmonary artery position between 2001 and 2017 at our institution were included. Freedom from endocarditis was analyzed using the Kaplan-Meier method and parametric survival regression models. RESULTS: Overall, 228 patients underwent placement of 253 BJV grafts. The median duration of conduit follow-up was 6 years (5 months to 14 years). Twenty-five conduits developed endocarditis, yielding an incidence of 10% at a median of 7.5 years after surgery. Median duration of symptoms before the diagnosis of endocarditis was 21 days (3-180 days). The most common infectious agents were viridans streptococci (n = 13; 52%). Freedom from endocarditis at 5 and 10 years was 97% and 77%, respectively. After controlling for confounders, BJV grafts had a higher incidence of endocarditis compared with homografts (P < .001). Twenty-three (92%) of the conduits that developed endocarditis were managed surgically, with no mortality. CONCLUSIONS: The incidence of late endocarditis affecting BJV is high. Increased surveillance and a high index of suspicion for endocarditis are warranted in patients who have undergone implantation of BJV grafts, especially if the graft has been in place for more than 7 years. When infective endocarditis has been diagnosed in these grafts, surgical replacement is recommended, with excellent outcomes.

Transcatheter Pulmonary Valve Replacement With the Melody Valve in Small Diameter Expandable Right Ventricular Outflow Tract Conduits.

OBJECTIVES: This study sought to evaluate the safety, feasibility, and outcomes of transcatheter pulmonary valve replacement (TPVR) in conduits ≤16 mm in diameter. BACKGROUND: The Melody valve (Medtronic, Minneapolis, Minnesota) is approved for the treatment of dysfunctional right ventricular outflow tract (RVOT) conduits ≥16 mm in diameter at the time of implant. Limited data are available regarding the use of this device in smaller conduits. METHODS: The study retrospectively evaluated patients from 9 centers who underwent percutaneous TPVR into a conduit that was ≤16 mm in diameter at the time of implant, and reported procedural characteristics and outcomes. RESULTS: A total of 140 patients were included and 117 patients (78%; median age and weight 11 years of age and 35 kg, respectively) underwent successful TPVR. The median original conduit diameter was 15 (range: 9 to 16) mm, and the median narrowest conduit diameter was 11 (range: 4 to 23) mm. Conduits were enlarged to a median diameter of 19 mm (29% larger than the implanted diameter), with no difference between conduits. There was significant hemodynamic improvement post-implant, with a residual peak RVOT pressure gradient of 7 mm Hg (p < 0.001) and no significant pulmonary regurgitation. During a median follow-up of 2.0 years, freedom from RVOT reintervention was 97% and 89% at 2 and 4 years, respectively, and there were no deaths and 5 cases of endocarditis (incidence rate 2.0% per patient-year). CONCLUSIONS: In this preliminary experience, TPVR with the Melody valve into expandable small diameter conduits was feasible and safe, with favorable early and long-term procedural and hemodynamic outcomes.

Globular chitosan treatment of bovine jugular veins: evidence of anticalcification efficacy in the subcutaneous rat model.

Vascular xenografts are widely used in cardiovascular surgery as an alternative to autologous vessels and vascular allografts. Calcification is one of the main drawbacks of vascular grafts, especially among young patients and children. Among different anticalcification approaches, chitosan emerges as a highly promising candidate due to its versatility, natural origin, and biocompatibility. We investigated the anticalcification efficacy of globular chitosan ("Chitozol") as it demonstrated the improved rate of water solubility as compared with conventional linear macromolecules of chitosan. In addition, we supposed that compact globular form of "Chitozol" molecules could provide effective penetration of extracellular matrix of bovine jugular veins (BJVs). Our results revealed that "Chitozol" treatment mitigated calcification in the experimental groups as compared to the control groups (without any treatment, conventional treatment with glutaraldehyde, and commercially available Contegra conduit). Different concentrations of "Chitozol" (0.3% and 3%), as well as different incubation times (15 and 30min), were equally effective in the prevention of calcification. In addition, "Chitozol" treatment with decellularization of BJVs demonstrated slightly improved stress-strain properties of unimplanted samples. Thus, the filling of fresh BJV with globular chitosan is proposed as a promising emerging treatment for the mitigation of calcific degeneration in BJVs xenografts.