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OBJECTIVES Mechanical composite valve grafts (MCVGs) are the first-line therapy for aortic root replacement in young adults. Decellularized aortic homografts (DAH) present a promising novel alternative due to their lower thrombogenicity. We aimed to compare both treatment options regarding survival and valve-related adverse events. METHODS This study was designed as a single-centre retrospective cohort study including patients who underwent root replacement with MCVG or DAH between 2000 and 2022. Urgent or emergent procedures were excluded. RESULTS The study cohort included 289 patients (MCVG n  = 216, DAH n  = 73) with a mean age of 48.5 ± 12 years (MCVG 49 ± 12 years vs DAH 47 ± 11 years; P  = 0.23) and a median EuroScore II of 1.7% (1.2, 2.6). The 30-day mortality was 1% (n  = 3). Cumulative survival at 3 years was 99% for DAH and 94% for MCVG, respectively (P  = 0.15). Mean follow-up was 98.9 ± 72.7 months. Bleeding events (n  = 14, 6.5%) and thromboembolism (n  = 14, 6.5%) were only observed in the MCVG group (P  = 0.19 and 0.09, respectively). Four cases (5%) of moderate structural valve deterioration occurred, all in the DAH group (P  ≤ 0.001). The cumulative incidence of a composite end point of valve-related adverse events was significantly higher in the MCVG group (P  = 0.0295). CONCLUSIONS Aortic root replacement with MCVGs and decellularized aortic homografts showed low mortality in an elective setting. Patients in the homograft cohort demonstrated significantly higher freedom from valve-related adverse events. DAH present a promising treatment option for young patients requiring root replacement; however, data on long-term durability are needed. [ABSTRACT FROM AUTHOR]

OBJECTIVES Aortic valved allografts (homografts) have been used alternatively to mechanical or biological valve prostheses in expectation of better durability; however, homograft valves do degenerate, and redo procedures have proven challenging due to heavy wall calcification. The aim of the study was to compare the outcome of open surgical (SAVR) and transcatheter aortic valve replacement (TAVR) in degenerated homografts. METHODS Between 1993 and 2022, 81 patients underwent repeat aortic valve procedures having previously received an aortic homograft. The redo had become necessary due to regurgitation in 85% and stenosis in 15%. Sixty-five percent underwent open surgery, 35% TAVR. RESULTS Isolated SAVR was possible in 79%, and root procedures were necessary in 21%. TAVR was performed in 79% via transfemoral and 21% via transapical access. Median prosthetic valve size was 23 (22.3–23.2) mm in the SAVR and 26 (25.2–26.9) in the TAVR group. Thirty-day mortality was 0% in the TAVR and 7% in the SAVR group (P  = n.s.). TAVR showed a significantly better outcome concerning prolonged ventilation (0 vs 21%, P  = 0.013) as well as ICU (1 vs 2 days; P  < 0.001) and in-hospital stay (10.5 vs 13 days; P  = 0.028). Five-year survival was statistically comparable between groups, and no severe leakage was observed. CONCLUSIONS SAVR following structural homograft degeneration shows acceptable results, but the perioperative risk remains substantial and poorly predictable. TAVR presents a reasonable and more easily accessible alternative and is associated with good short- and mid-term results. In the absence of relevant contraindications, TAVR is presently the preferred treatment option for these patients at our center. [ABSTRACT FROM AUTHOR]

Relevant pressure recovery (PR) has been shown to increase functional stenotic aortic valve orifice area and reduce left ventricular load. However, little is known about the relevance of PR in the pulmonary artery. The study examined the impact of PR using 2D‐echocardiography in the pulmonary artery distal to the degenerated homograft in patients after Ross surgery. Ninety‐two patients with pulmonary homograft were investigated by Doppler echocardiography (mean time interval after surgery 31 ± 26 months). PR was measured as a function of pulmonary artery diameter determined by computed tomography angiography. Homograft orifice area, valve resistance, and transvalvular stroke work were calculated with and without considering PR. PR decreased as the pulmonary artery diameter increased (r = −0.69, p < 0.001). Mean PR was 41.5 ± 7.1% of the Doppler‐derived pressure gradient (Pmax), which resulted in a markedly increased homograft orifice area (energy loss coefficient index [ELCOI] vs. effective orifice area index [EOAI], 1.3 ± 0.4 cm2/m2 vs. 0.9 ± 0.4 cm2/m2, p < 0.001). PR significantly reduced homograft resistance and transvalvular stroke work (822 ± 433 vs. 349 ± 220 mmHg × ml, p < 0.0001). When PR was considered, the correlations of the parameters used were significantly better, and 11 of 18 patients (61%) in the group with severe homograft stenosis (EOAI <0.6 cm2/m2) could be reclassified as moderate stenosis. Our results showed that the Doppler measurements overestimated the degree of homograft stenosis and thus the right ventricular load, when PR was neglected in the pulmonary artery. Therefore, Doppler measurements that ignore PR can misclassify homograft stenosis and may lead to premature surgery. [ABSTRACT FROM AUTHOR]

Aortic homografts are composed of aortic roots and variable lengths of the arch and ascending aorta, harvested from donor hearts. They are primarily used in extensive aortic root endocarditis due to its resistance to reinfection. They are, however, prone to structural failure. Redo aortic root surgery is challenging, especially in the setting of aneurysms or pseudoaneurysms (PSAN) lying immediately posterior to the sternum or adhering to it. We present a 43-year-old female with two aortic homograft pseudoaneurysms following her fourth aortic valve and ascending aortic procedure. The first PSAN was described as immediately cranial to proximal homograft anastomosis, measuring 21x8 millimeters. It harbored potential for intraoperative rupture because of its proximity to the posterior sternal table. The second one was 36x20 millimeters, adjacent to the distal homograft anastomosis. The surgical plan entailed institution of peripheral hypothermic cardiopulmonary bypass due to an almost inevitable risk of bleeding from the retrosternal pseudoaneurysm. While the actual sternotomy was uneventful, the PSAN ruptured after sternal retraction. The ensuing massive bleeding was expected and was successfully managed during hypothermic circulatory arrest. The patient had an unremarkable postoperative course and was discharged home. [ABSTRACT FROM AUTHOR]

Background: Surgical repair for patients with congenital heart disease (CHD) often incorporates homograft tissue or other foreign material that can lead to allosensitization. We sought to identify the relationship between pre‐sensitization prior to heart transplant and exposure to homograft tissue in CHD patients. Methods: Retrospective chart review of all CHD patients who underwent heart transplant at a major pediatric transplant center between 1/1/2011‐3/31/18. Operative records determined use of homograft tissue or foreign material. Panel reactive antibody (PRA) and LuminexTM single‐antigen bead (SAB) testing results were reviewed. Statistical analysis determined odds of pre‐sensitization in patients exposed to homograft tissue. Results: Fifty‐six CHD patients underwent transplant during the review period. Thirteen patients (23%) were pre‐sensitized by PRA>10%. By SAB testing, 33 patients (59%) developed any anti‐HLA antibody >0 MFI, 30 patients (54%) >2000 MFI, and 19 patients (34%) >6000 MFI. Patients with homografts were more likely to be pre‐sensitized by PRA (OR = 7.31, p =.007), and to have developed any anti‐HLA antibody at various levels, >0 (OR = 4.52, p =.034), >2000 (OR = 8.59, p =.003), and >6000 (OR = 8.50, p =.004). Of patients with homografts, those pre‐sensitized by PRA had longer exposure times (9.80 vs 4.96 years, p =.025). There was no difference in exposure time with relation to pre‐sensitization by SAB testing. Conclusions: Previous exposure to homograft tissue appears to increase the odds of pre‐sensitization by either the PRA or SAB testing. Longer exposure time to homograft tissue prior to transplant is associated with increased pre‐sensitization at transplant as determined by PRA, though not by SAB testing. [ABSTRACT FROM AUTHOR]

Background: Partial anomalous pulmonary venous connection (PAPVC) occurs when at least one pulmonary vein drains into the right atrium or its tributaries rather than the left atrium, most commonly connecting with the superior vena cava (SVC). The Warden procedure involves transecting the SVC proximal to the uppermost connection of the pulmonary vein followed by proximal SVC reattachment to the right atrial appendage. However, descending thoracic aortic homograft replacement for SVC translocation has recently been introduced as a modified technique. Aims: This commentary aims to discuss the recent study by Said et al. who reported their experiences with six PAPVC cases undergoing a modified Warden procedure using thoracic aortic homograft SVC translocation. Methods: A comprehensive literature search was performed using multiple electronic databases to collate the relevant research evidence. Results: The Warden procedure is associated with a 10% incidence of SVC obstruction with many requiring reintervention. Meanwhile, using the aortic homograft for SVC translocation, Said et al. observed no SVC obstructions. In addition, this modified technique does not require anticoagulation and has demonstrated an improvement in long‐term SVC patency. Nevertheless, it can be considered an expensive procedure. Moreover, since the thoracic aortic homograft utilized is biological tissue, only long‐term follow‐up will determine whether calcification and graft degeneration is an issue. Conclusion: It can be concluded that the modified Warden procedure is a safe and effective method to reconstruct the systemic venous drainage into the right atrium when a direct anastomosis under tension might be prone to re‐stenosis. [ABSTRACT FROM AUTHOR]

Background The ideal skin substitute should be more similar to normal skin function while causing fewer reactions. The purpose of this study was to assess the effect of radiotherapy on minimizing acute rejection and enhancing wound healing in children with deep burns. Patients and Methods A prospective randomized control study included 34 children admitted to the burn unit with deep burns under the age of 12 years. Through the tomotherapy device, a skin homograft from a related living donor was exposed to a local dose of radiotherapy of 500 centigray (cGy). It was immediately used for coverage of the prepared bed after the irradiation was completed. Results The mean values of the laboratory parameters (ESR, CRP, IL-6, and TNF) for all burn patients in the study showed a significant difference, with p < 0.001. The mean ± standard deviation (SD) of the time from homograft coverage to the appearance of rejection was 9.62 ± 1.45 in group 1 and 14.35 ± 2.8 in group 2, with p < 0.001 (highly significant difference), indicating that exposure to radiotherapy can reduce graft rejection. Conclusions The exposure of skin homografts from related living donors to a local low dose of radiotherapy can reduce a graft's ability to initiate inflammatory and immunological reactions, thereby minimizing rejection of a graft and enhancing epithelialization in children with deep second- and third-degree burns. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES Decellularized homograft valves (DHVs) have shown promising clinical results, particularly in the treatment of congenital heart disease. However, DHV appears to elicit an immune response in a subset of young patients, indicated by early valve degeneration. As the decellularization process is quality controlled for each DHV, we hypothesized that there may be residual immunogenicity within the extracellular matrix of DHV. METHODS A semi-quantitative dot blot analysis was established to screen for preformed recipient antibodies using secondary anti-human antibodies. Fifteen DHV samples (7 aortic, 8 pulmonary) were solubilized and exposed to serum from 20 healthy controls. RESULTS The sera from young controls (n = 10, 18–25 years) showed significantly stronger binding of preformed antibodies than sera from older individuals (n = 10, 48–73 years). The difference between the means of arbitrary units was 15.1 ± 6.5 (P = 0.0315). There was high intraindividual variance in the mean amounts of arbitrary units of antibody binding with some healthy controls showing >10 times higher antibody binding towards 2 different DHV. The amount of preformed antibodies bound to DHVs was higher in aortic than in pulmonary DHVs. The mean number of antibody binding (in arbitrary units) was 17.2 ± 4.5 in aortic and 14.5 ± 4.7 in pulmonary DHV (P  = 0.27). The amount of preformed antibodies bound to pulmonary DHVs was statistically significantly higher in the sera of healthy males (n  = 10) than in the sera of healthy females (n  = 10). The mean number of arbitrary units was 17.2 ± 4.2 in male and 11.7 ± 5.3 in female sera (P  = 0.036). Antibody binding to aortic DHV was also higher in males, but not significant (18.8 ± 5.0 vs 15.6 ± 4.0). Blood group (ABO) incompatibility between the serum from controls and DHV showed no impact on antibody binding, and there was no age-related impact among DHV donors. CONCLUSIONS Residual immunogenicity of decellularized homografts appears to exist despite almost complete cell removal. The established dot blot method allows a semi-quantitative assessment of the individual immune response towards extracellular DHV components and potentially the possibility of preoperative homograft matching. [ABSTRACT FROM AUTHOR]

Objective: Surgical reoperation for aortic homograft structural valve degeneration (SVD) is a high‐risk procedure. Transcatheter aortic valve replacement (TAVR) for homograft‐SVD is an alternative to reoperation, but descriptions of implantation techniques are limited. This study compares outcome in patients undergoing into two groups by the type of previously implanted aortic valve prosthesis: TAVR for failed aortic homografts (TAVR‐H) or for stented aortic bioprostheses (TAVR‐BP). Methods: From 2015 to 2017, TAVR was performed in 41 patients with SVD. Thirty‐three patients in the TAVR‐BP group (six for SVD of valved conduits), and eight patients in the TAVR‐H group. The Valve Academic Research Consortium criteria were used for outcome reporting purposes. Results: The patients with TAVR‐BP had predominant prosthetic stenosis (94%, p =.002), whereas TAVR‐H individuals presented mostly with regurgitation (88%, p = <.001). Patients with TAVR‐H received: Sapien‐3 (6), Sapien‐XT (1), and CoreValve (1) devices. Low, 40% ventricular fixation in relation to homograft annulus was attempted to anchor the prosthesis on the homograft suture‐line. One patient with TAVR‐BP experienced intraoperative distal prosthesis migration and Type‐B aortic dissection, and two patients in the TAVR‐H group had late postoperative proximal device migration. In both groups, there was zero 30‐day mortality, stroke, or pacemaker implantation. Conclusions: TAVR for failing aortic homografts may be a feasible and safe alternative to high‐risk surgical reintervention. Precise, 40%‐ventricular device positioning appears crucial for prevention of late paravalvular leak/late prosthesis migration and minimizing the risk of repeat surgical intervention. [ABSTRACT FROM AUTHOR]

Background: Homograft tissue is an important reconstructive material used in the surgical correction of a variety of congenital heart defects. The aim of this study is to evaluate the long-term outcome of pulmonary artery (PA) branch patches used in the reconstruction of the thoracic aorta in children.Methods: Retrospective review of 124 consecutive pediatric patients undergoing corrective surgery for their congenital heart defects between 2001 and 2016. Survival, reoperation, and reintervention data were collected, as well as imaging data to assess for presence of recoarctation, dilation, or aneurysm formation in the area of patch reconstruction.Results: Overall 15-year survival was 83.9% and 15-year freedom from reintervention in the area of patch reconstruction was 89.2%. Rates of mortality (0%), cardiac transplantation (0%), and reoperation (0.8%) attributable to the area of patch reconstruction were low. The frequency of catheter-based intervention in the area of patch reconstruction was 9.7%; such interventions were successful in all but one patient, who ultimately underwent successful surgical aortoplasty.Conclusions: Homograft patches harvested from PA branches are an effective reconstructive material used for reconstruction of the aorta in small children. Long-term results show no risk of aneurysm formation and low rates of stenosis formation. [ABSTRACT FROM AUTHOR]

Objective: In the previous decade, several reports have been published regarding implants inserted in autografts, but none have analyzed implants inserted in fresh-frozen bone allografts. Thus, a retrospective study was planned to verify if 4-months' delay from grafting to implant insertion is a safe period before prosthetic rehabilitation of implants placed in fresh-frozen bone allografts. Method and Materials: Between December 2003 and December 2006, 22 patients (10 women and 12 men with a median age of 51 years) underwent grafting with horizontal augmentation without membrane and 88 implants inserted thereafter. The mean implant follow-up was 27 months. Implants used were 30 double etched (3i, Osseotite, Biomet), 10 SLA1 (Astratech), 26 anodic oxidized (Nobel Biocare), 12 CaPO4 ceramic-blasted (Lifecore Biomedical), 7 SLA2 (Sweden & Martina Spa), 2 ITI (Straumann), and 1 Biotec (Povolaro di Dueville). Implant diameter and length ranged from 3.25 to 5.0 mm and from 8.0 to 15.0 mm, respectively. Implants were inserted to replace 10 incisors, 7 canines, 36 premolars, and 35 molars. Results: No implants were lost (ie, survival rate = 100%). No difference was detected when comparing implants loaded after 4 months versus those loaded after 6 or more months (209 implants). Conclusion: Four-months' delay from grafting to implant insertion is a safe period to obtain a high survival rate and success rate for implants inserted in fresh-frozen bone. [ABSTRACT FROM AUTHOR]

Background: Redo surgery in patient who underwent aortic valve replacement with an aortic homograft can result technically challenging because of the massive calcification of the conduit.Case Presentation: We present a case of a patient who underwent open surgery on cardiopulmonary bypass assistance to implant a standard transcatheter aortic bioprosthesis through aortotomy in an off-label procedure and we discuss its safety and feasibility.Conclusions: The combination of open cardiac surgery and open trans-aortic implant of a transcatheter prosthesis may reduce the surgical risk shrinking the technical difficulties that the implantation of a standard surgical prosthesis would have given. [ABSTRACT FROM AUTHOR]

View large Download slide View large Download slide OBJECTIVES The aim of this study was to compare the performance of pulmonary homografts with stentless bioprosthetic valves [Medtronic Freestyle™ (Medtronic, Minneapolis, MN, USA)] in the pulmonary position in patients with congenital heart disease (CHD) younger than 20 years. METHODS Between January 2000 and December 2017, 215 patients were retrospectively identified from hospital databases in 3 congenital heart centres in Australia. Valve performance was evaluated using standard criteria. Propensity score matching was used to balance the 2 treatment groups. RESULTS Freedom from reintervention for patients who received a pulmonary homograft (n  = 163) was 96%, 88% and 81% at 5, 10 and 15 years and for patients who received a Freestyle™ valve (n  = 52) was 98%, 89% and 31% at 5, 10 and 15 years, respectively. Freedom from structural valve degeneration for patients with a homograft was 92%, 87% and 77% at 5, 10 and 15 years and for patients with a Freestyle valve was 96%, 80% and 14% at 5, 10 and 15 years, respectively. In the first 10 years, there was no difference in outcomes [reintervention hazard ratios (HR) = 0.69, 95% confidence intervals (CI) (0.20–2.42), P  = 0.56; structural valve degeneration HR = 0.92 (0.34–2.51), P  = 0.87]. After 10 years, the recipients of the Freestyle valves were at higher risk of both outcomes [reintervention HR = 7.89; 95% CI (2.79–22.34), P  < 0.001; structural valve degeneration HR = 7.41 (2.77–19.84), P  < 0.001]. The findings were similar when analysed by implantation in the orthotopic position and in the propensity-matched groups. CONCLUSIONS The Freestyle stentless bioprosthetic valve is a comparable alternative to cryopreserved pulmonary homografts up to 10 years after implantation when implanted in an orthotopic pulmonary position in patients younger than 20 years with CHD. [ABSTRACT FROM AUTHOR]

Microbiological contamination of retrieved tissues has become an issue of key importance and is a critical aspect of allograft safety, especially in the case of multi-tissue donations, which frequently become contaminated during retrieval and handling. We analysed contamination in 11,129 tissues with a longitudinal contamination profile for each individual tissue. Specifically, 10,035 musculoskeletal tissues and 1094 cardiovascular tissues were retrieved from a total of 763 multi-tissue donors, of whom 105 heart-beating organ donors and 658 deceased tissue donors. Of the 1955 tissues found to be contaminated after the first decontamination step, 1401 tissues (72%) were contaminated by the same species as the one(s) isolated at retrieval (Time1) and 554 (28%) by different species. Among the 113 tissues testing positive after the 2nd decontamination (Time3), 36 tissues (32%) were contaminated by the same species detected at Timel while the contaminating species differed from Time1 in 77 tissues (68%). The higher the number of contaminating species per tissue the higher the percentage of tissues in which contamination changed over time compared to Time1. The analysis revealed a 28% incidence of new species in tissues already testing positive after retrieval and of 3.5% of tissues becoming positive after admission to the tissue bank. Of these, coagulase-negative Staphylococcus accounted for over 70% of new contaminations. [ABSTRACT FROM AUTHOR]

OBJECTIVES We aimed to compare the long-term performance of pulmonary homografts and stented bioprosthetic valves in the pulmonary position in patients aged 10–20 years. METHODS Between January 1995 and December 2015, 188 patients aged 10–20 years undergoing pulmonary valve replacement were identified retrospectively from hospital databases in both congenital cardiac centres in Brisbane. Valve performance was evaluated using previously described standard criteria. Propensity score matching was used to balance the 2 treatment groups. RESULTS Freedom from structural valve degeneration in homografts (n  = 131) was 97%, 92% and 85% at 3, 5 and 10 years, respectively, and 91% and 53% at 3 and 5 years, respectively, in the bioprosthesis group (n  = 57). Freedom from reintervention in homografts was 96%, 93% and 88% at 3, 5 and 10 years, respectively, and 93% and 68% at 3 and 5 years, respectively, in the bioprosthesis group. The unadjusted Cox regression analysis demonstrated that a bioprosthesis was at 5.64 times the risk of structural valve degeneration and 3.89 times the risk of reintervention. The Cox regression analysis performed on the propensity matched sample (45 pairs of patients) revealed that a bioprosthesis was at almost 10 times the risk of experiencing structural valve degeneration [hazard ratio (HR) = 9.18] and at more than 8 times the risk of undergoing a reintervention (HR = 8.34). CONCLUSIONS In our patient population, pulmonary homografts outperformed stented bioprosthetic valves within 5 years when implanted in the pulmonary position in patients aged 10–20 years. We recommend the use of a pulmonary homograft for pulmonary valve replacement in this age group in patients undergoing surgery for congenital heart disease. [ABSTRACT FROM AUTHOR]

OBJECTIVES Recent studies have shown favourable early results with decellularized allografts (DAs) for right ventricular outflow tract reconstruction during the Ross procedure. However, mid- and long-term outcome data are still scarce. The objective of this study was to compare the durability of fresh DAs with standard cryopreserved allografts (SCAs) in patients undergoing the Ross procedure. METHODS Two hundred patients underwent the Ross procedure with DA and 202 with SCA. Using propensity score matching, mid- and long-term clinical outcome and echocardiographic allograft function over time were compared. RESULTS One hundred and thirty DA patients (median age 28 years, 71.5% men, mean follow-up 4.2 ± 2.6 years) were matched with 130 SCA patients (median age 30 years, 69.2% men, mean follow-up 13 ± 4.5 years). After matching, there were no differences in baseline characteristics. In the matched DA vs SCA groups, actuarial 8-year freedom from allograft dysfunction (DA = 86.7% vs SCA = 87.3%, P  = 0.183) and freedom from allograft reintervention (DA = 99.2% vs SCA = 97.6%, P  = 0.642) were comparable. Longitudinal echocardiographic analyses showed a significantly lower progression rate of peak right ventricular outflow tract gradients in the DA group during the first 3 years after the operation. Absolute gradients over time were slightly lower in DA when compared with SCA, although 95% confidence intervals overlapped. CONCLUSIONS Up to 8 years of follow-up, DA and SCA used for right ventricular outflow tract reconstruction in the Ross procedure are associated with comparably excellent clinical and haemodynamic outcome. Longer follow-up and dedicated echocardiographic studies are still necessary to confirm the long-term performance of the DAs. [ABSTRACT FROM AUTHOR]

Background: Repair of congenital heart defects involving the right ventricular outflow tract may require the implantation of a right ventricle to pulmonary artery conduit. This conduit is likely to be replaced during childhood. This study compares the operative outcomes of the replacement procedure of Contegra® and homografts in pulmonary position.Methods: From 1999 to 2016, 82 children underwent 87 right ventricle to pulmonary artery conduit replacements (60 Contegra® and 27 homografts). Demographics, operative and clinical data were obtained through a retrospective review of the medical records. The two groups were matched for comparison using propensity score matching. All the procedures were performed by the same team of surgeons.Results: No statistically significant difference was observed between the two groups when considering the operative data for anesthesia, surgery, cardiopulmonary bypass and aortic clamping durations. A peroperative complication rate of 13.47% and 15.36% in Contegra® and homograft replacement groups respectively (p value = 0.758) was observed. There was no difference regarding the blood loss and fluid input. No statistically significant difference was observed between the two groups for the post-operative morbidity. We considered the Pediatric Risk of Mortality (PRISM) score, the day of extubation, the day of withdrawal of inotropic drugs, the length of the intensive care unit stay and the length of hospital stay. The overall mortality is 2.3% but there is no statistically significant difference between the two groups.Conclusion: Right ventricle to pulmonary artery conduit replacement procedure can be achieved with a low surgical morbidity or mortality, not influenced by the type of conduit that is replaced. Therefore, the choice between homograft or Contegra® for right ventricle to pulmonary artery reconstruction should not be influenced by the future surgical risk during the replacement procedure.Trial Registration: NCT03048071 . Registered 9 February 2017 (retrospectively registered). [ABSTRACT FROM AUTHOR]

Durability and the rate of complications of homograft heart valves, adjusted for patient-related contributors and surgical techniques, rely mainly on the quality of allografts which in turn are mirrored in the donor characteristics and most importantly recovery and processing procedures. Aimed to assess the quality, a study was conducted to figure out the durability and late outcome following homograft replacement with valved conduits procured by the Iranian Tissue Bank. Retrospectively, the pre-implantation, perioperative and follow-up data of 400 non-consecutive recipients of cryopreserved heart valves (222 pulmonary and 178 aortic) from 2006 to 2015 were collected and analyzed in terms of variables reflecting late outcome including adverse events and durability. In the context of durability, the event of interest was defined as the need for homograft replacement and homograft-related death. The mean follow-up time (SD) of study entrants (male/female ratio, 1.4) was 49.8 (36.3) months. Median age at the time of implantation was 11 years. Total 10-years mortality was 21 % (84/400), including 66.7 % early (30-days mortality: 56/84) and 33.3 % late (28/84). Overall late complication rate was 2 %. Median survival time was 120 months (95 % CI 83.3-156.6). The pulmonary valves appeared to be more durable (P value <0.001) and survival probabilities in small sized grafts were lower (P value 0.008). One-, five-, and ten-year graft survival was 82, 76 and 73 %, respectively. The evidences suggest that the homografts function satisfactory with low rate of late complications; nevertheless, more emphasis should be given to make long-term durability comparable. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Treatment of infected thoracic aortic grafts is associated with considerable morbidity and mortality. The replacement of an infected graft is an effective strategy, yet a complex surgical endeavour, especially if the aortic root or aortic arch is involved. In situ graftsparing surgical therapy with continuous mediastinal irrigation after surgical debridement might offer an alternative in the management of early graft infections in the thoracic aorta. METHODS: Between 1996 and August 2015, 25 patients were treated in our institution for early graft infection after thoracic aortic surgery via sternotomy. In 11 patients, the infected prosthesis was replaced by a cryopreserved homograft or a biological valved pericardial xenograft. In 14 patients, an attempt to salvage the graft was made by resternotomy, aggressive debridement and subsequent continuous mediastinal antibiotic irrigation over a course of 2 weeks, accompanied by systemic antibiotic therapy. RESULTS: In-hospital mortality was comparable (replacement group: 2/11 = 18%, graft-sparing group: 2/14 = 14%, P = ns). The time interval from the initial surgery was significantly shorter in the graft-sparing group (replacement group: 165 days [range 95-300 days] and graftsparing group: 24 days [range 15-93 days], P = 0.004]. Two patients (14%), who were treated with the graft-sparing approach >100 days after the initial surgery, were retreated for infection, and 1 due to an intra-aortic infection of an aortic arch hybrid stent graft was not amenable to external irrigation (median follow-up: 1.5 years [range 1.1-2.1 years]). One patient in the replacement group (9%) was reoperated on due to homograft degeneration (median follow-up: 6.0 years [3.0-8.9 years]). CONCLUSIONS: In situ graft-sparing surgical therapy is safe and effective if diagnosis and treatment of aortic graft infection is initiated promptly and aggressively (ideally <1 month post-surgery). Our method produces good midterm results (3 years). For aortic graft infections that become clinically apparent >3-6 months after surgery, replacement of grafts with biological conduits (homografts or pericardial xenografts) most likely remains the best treatment option. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Decellularized homografts have shown auspicious early results when used for pulmonary valve replacement (PVR) in congenital heart disease. The first clinical application in children was performed in 2002, initially using pre-seeding with endogenous progenitor cells. Since 2005, only non-seeded, fresh decellularized allografts have been implanted after spontaneous recellularization was observed by several groups. METHODS: A matched comparison of decellularized fresh pulmonary homografts (DPHs) implanted for PVR with cryopreserved pulmonary homografts (CHs) and bovine jugular vein conduits (BJVs) was conducted. Patients' age at implantation, the type of congenital malformation, number of previous cardiac operations and number of previous PVRs were considered for matching purposes, using an updated contemporary registry of right ventricular outflow tract conduits (2300 included conduits, >12 000 patient-years). RESULTS: A total of 131 DPHs were implanted for PVR in the period from January 2005 to September 2015. Of the 131, 38 were implanted within prospective trials on DPH from October 2014 onwards and were therefore not analysed within this study. A total of 93 DPH patients (58 males, 35 females) formed the study cohort and were matched to 93 CH and 93 BJV patients. The mean age at DPH implantation was 15.8 ± 10.21 years (CH 15.9 ± 10.4, BJV 15.6 ± 9.9) and the mean DPH diameter was 23.9 mm (CH 23.3 ± 3.6, BJV 19.9 ± 2.9). There was 100% follow-up for DPH, including 905 examinations with a mean follow-up of 4.59 ± 2.76 years (CH 7.4 ± 5.8, BJV 6.4 ± 3.8), amounting to 427.27 patient-years in total (CH 678.3, BJV 553.0). Tetralogy-of-Fallot was the most frequent malformation (DPH 50.5%, CH 54.8%, BJV 68.8%). At 10 years, the rate of freedom of explantation was 100% for DPH, 84.2% for CH (P = 0.01) and 84.3% for BJV (P= 0.01); the rate of freedom from explantation and peak trans-conduit gradient =50 mmHg was 86% for DPH, 64% for CH (n.s.) and 49% for BJV (P < 0.001); the rate of freedom from infective endocarditis (IE) was 100% for DPH, 97.3 ± 1.9% within the matched CH patients (P = 0.2) and 94.3 ± 2.8% for BJV patients (P = 0.06). DPH valve annulus diameters converged towards normal Z-values throughout the observation period, in contrast to other valve prostheses (BJV). CONCLUSIONS: Mid-term results of DPH for PVR confirm earlier results of reduced re-operation rates compared with CH and BJV. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Small-sized homografts are rare but may be required for the reconstruction of the right ventricular outflow tract (RVOT). Down-sizing adult-sized homografts can be an option to overcome the shortage of availability. METHODS: Since 1994, we have been down-sizing adult-sized homografts by excising one cusp. The aim of the study was to analyse the durability of down-sized homografts and compare it with small-sized homografts in a paediatric population. All patients below a body weight of 14 kg were included in the study. The end-point of the study was homograft failure. RESULTS: A total of 152 patients met the inclusion criteria of the study, of which 82 patients (54%) received a down-sized homograft. The median age was 17.1 (0.3-64.8) months and the mean weight 8.4 ± 3.4 kg. Fifty-eight patients (38%) were under 1 year and 10 (6.5%) under 1 month of age at the time of homograft implantation. The mean homograft size of the whole study population was 14.7 ± 2.5 mm and the mean z-score was 1.6 ± 0.9. The median follow-up time was 10 (0.03-19.7) years. Early mortality after homograft implantation was 5% (n = 8), 4 of these patients had received a down-sized homograft. The study population comprised early survivors, that is, 144 patients. During follow-up, a total of 46 homografts failed, 23 in each group, after a mean time of 5.7 ± 4.2 years. Freedom from homograft failure was 94.6 ± 2.6, 87.2 ± 4 and 68.6 ± 6.6% for down-sized homografts and 95.2 ± 2.7, 78.7 ± 5.5 and 61 ± 7% for small-sized homografts at 1, 5 and 10 years, respectively (P = 0.3). Risk factors for homograft failure in the multivariable analysis were a homograft z-score of <1 and age below 1 year at the time of implantation (P = 0.02). CONCLUSION: Down-sized homografts demonstrated a durability similar to that of small-sized homografts. Therefore, down-sizing adultsized homografts by creating a bicuspid valve to fit into the corresponding RVOT in children with congenital heart defects is an excellent method to overcome the shortage of small-sized homografts. [ABSTRACT FROM AUTHOR]

Background The bovine jugular vein ( Contegra) conduit has been described as an alternative to the homograft for right ventricle ( RV) to pulmonary artery ( PA) connection. We assessed the outcomes of Contegra conduits and homografts at a single institution. Methods We conducted a retrospective review of children ( n = 249) who underwent RV-to- PA conduit ( Contegra or homograft) implantation from 2001 to 2011. Results Median operation age was 4.8 years (2 days-18 years). Indications for surgery were as follows: primary conduit insertion ( n = 131; 53%), previous conduit failure ( n = 57; 23%) or Ross procedure ( n = 61; 25%). There were 113 (45%) Contegra conduits and 136 (55%) homografts (92 pulmonary, 44 aortic) inserted. Early mortality was 5% ( n = 12). Overall survival was 89% (95% confidence interval ( CI): 84-92%) at 5 years and 87% (95% CI: 81-92%) at 10 years. Mortality was associated with smaller conduit size ( P = 0.044) and syndrome diagnosis ( P = 0.012). Freedom from reoperation was 85% (95% CI: 77-91%) and 75% (95% CI: 59-86%) at 5 years for homografts and Contegra conduits, respectively. Patients required conduit replacement (15%) for endocarditis ( n = 4; 11%) or graft failure ( n = 34; 89%). Eleven patients developed distal conduit stenosis with the majority occurring in Contegra conduits ( n = 7; 64%) ( P = 0.004). A larger conduit ( P = 0.007) was protective against reoperation. There was no difference in reoperation between conduits ( P = 0.41). Mean follow-up was 5 ± 3.2 years (96% complete). Majority of survivors (99%) were in New York Heart Association Class II/ I. Conclusion The Contegra conduit and homograft demonstrate similar mid-term outcomes in children. Smaller conduit size is associated with higher graft failure and mortality. [ABSTRACT FROM AUTHOR]

Purposes The rationale of this study was to assess morphologically the effects of implantation of decellularized aortic and pulmonary homografts into growing sheep, with the objective to establish type and extent of cell repopulation and propensity to dystrophic calcification over a prolonged period of time. Methods Pulmonary and aortic homografts were obtained from healthy euthanized juvenile sheep (35–45 kg). Complete decellularization was accomplished in 0.5% sodium deoxycholate and 0.5% sodium dodecylsulfate for 24 h. Twelve homografts from 11 animals were studied as follows: - 2 native (1 pulmonary and 1 aortic) from the same animal; - 2 decellularized unimplanted (1 aortic and 1 pulmonary), from two different animals; - 8 decellularized (2 aortic and 6 pulmonary), implanted in 8 female animals for 14–21 months. Gross, X-ray, histology, immunohistochemistry, morphometry, transmission electron microscopy and calcium content spectroscopy investigations were carried out. Results Decellularization appeared complete in unimplanted homografts. The extracellular matrix was intact. Explanted homografts showed soft, pliable cusps without gross calcium deposits and tears; calcium content showed slight difference between aortic and pulmonary cusps (5.505±2.04 vs. 2.77±1.06 mg/g dry weight, P = .04). Microscopic calcifications were observed in two aortic homografts on smooth muscle cells of repopulated homograft wall and on valvular interstitial cells, respectively. Inflammatory infiltrates were never seen. Cell repopulation occurred in homograft wall with actin smooth muscle and vimentin positive cells in media lamellar units (cell density per millimeter squared, 885.4±424.38 in native vs. 172.64±160.33 in implanted homograft, P < .01) as well as in cusps (cell density per millimeter squared, 495.96±63.92 in native vs. 184.66±140.74 in implanted homograft, P < .01). The percentage area of recellularization was 71.27±3.03 in the homograft wall and 22.16±3.06 in the cusps. Thickness of pulmonary explanted homograft wall and cusps was 900.68±321.52 μm vs. 994.36±135.92 μm and 204.75±66.64 μm vs. 231.04±105.94, respectively ( P = NS), whereas in aortic homograft wall and cusps it was 1358.604±423.79 μm vs. 2065.32±431.46 μm, P = .016, and 248.01±93.95 μm vs. 390.30±104.81 μm, P = .03, respectively. The endothelial lining was restored. Conclusion Endogenous cell repopulation in decellularized homografts occurs and persists following implantation, at both wall and cusp level, without evidence of immune reaction. Even in the long term, the cusps exhibit no structural deterioration and negligible calcification. [ABSTRACT FROM AUTHOR]

Background: Aortic valve replacement in a patient with an aortic homograft can be very challenging, especially when concomitant mitral valve surgery needs to be performed.Case Presentation: We report a case of implantation of a sutureless aortic valve bioprosthesis combined with mitral valve replacement in a patient with a severely calcified aortic homograft where conventional valve replacement was technically unfeasible.Conclusions: We believe that sutureless AVR is a viable option especially for young patients with a high surgical risk where conventional valve replacement cannot be achieved. [ABSTRACT FROM AUTHOR]

Institutional practice at our hospital (Boston Children's Hospital) is to culture homografts before implantation during congenital cardiac surgery. Over a 4-year period, 5% (73 of 1376) of these cultures were positive, but the results had minimal clinical impact. Our experience demonstrates that there is limited utility in preimplantation cultures of cardiac homografts. [ABSTRACT FROM AUTHOR]

Background: Reconstruction of microtia is a challenging issue in otology. Autogenous costochondral reconstruction is the most widely accepted approach. However, it is time-consuming and has some limitations. Irradiated homograft costal cartilage has been proposed as a suitable alternative. In the present study, we represent our experience with this approach. Patients and Methods: A total of 19 ears were treated with irradiated homograft costal cartilage prepared from 18 to 40 years old cadaver under a standardized processing method. The reconstruction was achieved a two-stage procedure with at least 3 months interval. Results: The study population included 9 (56.25%) males and 7 (43.75%) females with the mean age of 13.7 ± 5.1 years. Microtia was bilateral in 3, right-sided in 8 and left-sided in 5 subjects. Averagely, subjects were followed for 36.0 ± 9.9 months during which none of the cases showed cartilage resorption. Short-term and long-term complications were negligible. Totally, 90% of subjects were satisfied with the procedure. Conclusion: Irradiated homograft costal cartilage resulted in relatively high satisfaction and low complication rates for auricular reconstruction. Esthetic appearances of the reconstructed auricle were acceptable. The advantages of this approach are the elimination of additional incisions for graft harvesting and donor-site morbidity. [ABSTRACT FROM AUTHOR]

Purpose: This randomized controlled trial compared fresh-frozen versus autologous bone blocks for maxillary horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. Materials and Methods: Twenty-four patients were allocated to the autologous and fresh-frozen groups in a 1:1 ratio. Patients underwent computed tomography scans 1 week and 6 months after surgery for graft volume and density analysis. Doxycycline was administered at day 120 and day 150 to label new bone formation. Biopsy for histologic and histomorphometric analyses was performed at reentry for implant insertion, 6 months after grafting. Results: Fresh-frozen grafts had lower density than autologous bone. Autologous and fresh-frozen grafts lost, respectively, 25% and 52% of their initial volume ( p = .0041). Histology revealed the presence of newly formed bone within both graft types, but clear signs of inflammation were present in fresh-frozen blocks. Conclusions: According to these 6-month results, autologous bone blocks are preferable to fresh-frozen bone grafts. [ABSTRACT FROM AUTHOR]

Superior vena cava (SVC) reconstruction is occasionally required in the treatment of benign and malignant conditions. We report a patient with symptomatic SVC obstruction secondary to mediastinal fibrosis successfully reconstructed with an aortic allograft. [ABSTRACT FROM AUTHOR]

OBJECTIVES The management of infected Dacron grafts in the ascending aortic position involving the aortic arch and aortic root remains a technical challenge. Total replacement of the infected graft material with cryopreserved homografts appears to be an effective treatment strategy for these patients. METHODS Seventeen consecutive patients were operated on for infection of their ascending aortic graft where the aortic arch was also involved 26 ± 33 months after initial surgery, in 70%, for type A aortic dissection (12 acute aortic dissection type A and 1 chronic aortic dissection type A). The aortic root was additionally affected in 14 patients. Computed tomography and echocardiography follow-up was performed in all patients. RESULTS Hospital mortality was 24% (n = 4). Cardiopulmonary bypass and aortic cross-clamp times were 288 ± 128 and 165 ± 78 min, respectively. In 14 patients, the aortic root was replaced. Hypothermic circulatory arrest was necessary in all patients (41 ± 25 min) with additional cold selective antegrade cerebral perfusion in 14 (41 ± 30 min). During follow-up, 1 patient died due to a cerebral haemorrhage at 3 months and another at 4 years, of pulmonary embolism. Two patients were successfully reoperated on for degeneration of the aortic valve at 16 and 94 months; 1 patient had an early degeneration of the homograft and needed re-replacement with a homograft. In 2 other patients, a stent graft had to be placed to cover the distal anastomosis between the homograft and native aorta. In all others, recent follow-up revealed no degeneration of the implanted homografts. CONCLUSIONS Surgery for infected Dacron grafts in the ascending aortic position with involvement of the arch can be performed with an acceptable perioperative mortality. In case of degeneration of the valve, reoperations can be performed with good results in experienced hands. Therefore, we consider the concept of complete explantation of all infected material and replacement with homografts a successful treatment strategy. Nevertheless, close follow-up of the patients is mandatory so as not to miss any degeneration or reinfection of the implanted grafts. [ABSTRACT FROM PUBLISHER]

OBJECTIVES Although data from large series indicate the satisfactory performance of bioprosthetic valves in the right ventricular outflow tract (RVOT), replacement of the pulmonary valve in adult patients undergoing the Ross procedure is usually performed with pulmonary allografts. We evaluated the outcomes of homografts vs. bioprosthetic RVOT replacement after the Ross procedure in adults. METHODS Between 1996 and 2011, a total of 186 adult patients (141 male; mean age 44 ± 10 years) underwent aortic root replacement with a pulmonary autograft. The RVOT was replaced with a homograft in 113 patients and with stentless bioprostheses (Medtronic Freestyle®) in 73. Patients were followed for a mean of 6 years (range 1–15 years; 1106 patient years). RESULTS Twelve patients required reintervention owing to dysfunction of the RVOT replacement, which was caused by endocarditis (n = 4), degeneration (n = 2) or stricture at the proximal suture line (n = 6). For homografts, the incidence of reintervention was 1 in 150 patient years, compared with 1 in 36 patient years for stentless bioprostheses (P = 0.007). The median gradient was 15 mmHg for the homograft group and 24 mmHg for bioprosthesis (P < 0.0001). The incidence of gradients >40 mmHg was 10-fold higher in the bioprosthetic group. CONCLUSIONS Patients with bioprostheses in the RVOT position after the Ross procedure showed a significantly higher risk of reintervention or pulmonary valve dysfunction. The main problem, early development of a stricture at the proximal suture line, has to be solved to achieve satisfactory bioprosthetic function in the RVOT. [ABSTRACT FROM AUTHOR]

Introduction: In the past 50 years, human cardiovascular tissue allografts, also called homografts, have been implanted into patients with different valvular diseases. The use of these allografts and the number of cardiovascular tissue banks and their respective techniques increased. We conducted a survey to establish the quantity of allografts processed, and issued by, European tissue banks. The survey also included the collection of other relevant statistics. Methods: In 2011, the Foundation of European Tissue Banks collected data from 19 different cardiovascular tissue banks in 11 European countries. Results: From 2007 to 2010 the data show a decrease in the number of hearts received, from 1700 to 1640 in 18 tissue banks; the average number of hearts received for cardiovascular tissue processing decreased from 113 to 91. The number of heart valves issued for transplantation increased from 1272 in 2007 to 1486 in 2010. The average rate of discard because of microbiological contamination was 20.7%, while 4.2% of the grafts were not used because of positive serology. Half of the tissue banks issued arterial grafts, while 3 banks also issued veins and pericardium. An overview of decontamination methods shows considerable methodological differences between 17 cardiovascular tissue banks. Conclusions: From the experience in Europe, it can be concluded that cardiovascular tissue banks have an established place in the domain of cardiovascular surgery. The statistics show fluctuating data concerning the demand for human cardiovascular allografts and methodological questions. There is room for growth and improvement with respect to validation of decontamination methods. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Histological evaluation of the fate of implanted ossicular homografts in adult New Zealand white rabbits after inactivation/preservation procedure. Design: The study was conducted on 10 pathogen free adult NZ white rabbits at the animal laboratory of Alexandria University Hospitals. Under general and local infiltrative anesthesia middle ear ossicles (incus and malleus) were collected bilaterally from another five rabbits. These ossicles underwent inactivation/preservation procedure using sodium hydroxide followed by autoclaving at 134°C for 8min and kept in a sterile autoclavable package. The treated ossicles were randomly implanted in the middle ear cavity of recipient rabbits. After one month, both the homograft and the ossicle of the same rabbit were retrieved and histologically examined. Results: All the harvested control ossicles from the same ear showed the regular histological structure of the compact bone. All harvested specimens of inactivated/preserved ossicular homograft maintained their shape, contour, size and physical integrity and were surrounded by a variable layer of fibro-vascular tissue. There was bone proliferative activity with new bone formation at the periphery underneath the periosteum and remodeling was evident around the bone marrow spaces. All harvested ossicular homografts did not show any granulomatous foreign body reaction. Conclusion: Inactivated/preserved ossicular homograft can be considered for partial ossicular reconstruction in some selected indications for patients lacking suitable autograft ossicles. [Copyright &y& Elsevier]

Abstract: Failure to develop antibodies to nonself A and B blood group antigens is well described after infant ABO-incompatible heart transplantation and suggests that exposure to incompatible ABO antigens early in life may lead to tolerance rather than immunogenicity. If this finding is also true following ABO-incompatible cryopreserved homograft implantation, then such patients who require transplantation may be able to accept certain ABO-incompatible organs. In this study, we measured anti-A and -B antibody titers (isohemagglutinins) and allosensitization to human leukocyte antigens (HLA) in 21 patients after homograft placement (12 of whom were <1 year of age at initial homograft exposure) in childhood. We also examined homograft explant specimens for endothelial preservation and expression of HLA and A and B blood group antigens. We observed no differences in isohemagglutinins between patients who received ABO-incompatible versus ABO-compatible homografts. Allosensitization to HLA was present in 88% of patients (9 of 9 ABO-incompatible recipients and 5 of 7 ABO-compatible recipients). In 7 homograft explant specimens (median implant duration 10.1 years), the vasa vasorum endothelium was intact with ABO blood group antigen expression on 3 of 5 non-O homografts. These data suggest that tolerance to incompatible A and B blood group antigens does not occur following placement of ABO-incompatible homografts in childhood. [Copyright &y& Elsevier]