Homograft Degeneration Research Articles

A Systematic Review of Clinical Outcomes of Pedicled Flap Repairs of the Knee Extensor Mechanism.

Rupture of the extensor mechanism of the knee has severe functional morbidity, and repair can be complicated by infection, allograft degeneration, and recurrent rupture. Techniques of autologous tissue repair utilizing pedicled flaps such as the gastrocnemius offer vascularized methods of reconstruction, with potentially diminished complication rates. The goal of this study was to evaluate the functional outcomes and complications associated with pedicled flap repair of the knee extensor mechanism. A systematic review was conducted following the Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines. Publications that focused on local myocutaneous flaps as a means for reconstruction were included. Causes for knee extensor mechanism deficit, flap characteristics, ambulation rate, changes in range of motion pre- and postoperation, and postoperative complications were analyzed. Technique reports including primary suture repairs, synthetic mesh, and allograft use were excluded. An initial 119 studies were identified, with final review of 22 observational studies encompassing 128 cases of pedicled flap reconstructions. The gastrocnemius (88.2%, n = 113), quadriceps (6.3%, n = 8), and a combination of the vastus and gastrocnemius flaps (5.5%, n = 7), were the most frequently utilized flaps. Functional outcomes were favorable with 87.2% of patients achieving ambulation without external support. Variability in range of motion outcomes across different flap may be secondary to the patient characteristics as well as extent of initial injury. Autologous pedicle flap reconstruction of the knee extensor mechanism emerges as a viable option for cases characterized by extensive defects and insufficient soft tissue coverage, which are not amenable to direct suture repairs or allografts. Postoperative assessments revealed that the majority of patients experienced improved ambulation status, with no instances of deterioration noted among the patients.

Aortic valved homograft degeneration: surgical or transcatheter approach for repeat aortic valve replacement?

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. 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. 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. 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.

BIOPROSTHETIC VALVE IMPLANTATION AS TYPE OF TRANSPLANTATION: IMMUNOLOGICAL CONSEQUENCES OF NEW CONCEPT

HighlightsImmune processes and mechanisms underlying bioprosthetic heart valve degeneration and rejection of allografts and xenografts are similar.Manufacturers and surgeons can implement effective approaches to prevent immune rejection in the process of production and implantation of prosthetic heart valves in order to delay the process of structural valve degeneration. AbstractBioprosthetic heart valves (BHV) are characterized by low thrombogenicity, thus circumventing the need for long‐term anticoagulation. However, BHV lifespan is limited to 10–15 years because its tissue components are subject to degeneration. Recent research data indicate that immune responses forming the basis of humoral and cellular rejection of allografts and xenografts play a major role in the development of structural valve degeneration (SVD). This review summarizes up-to-date data on immune processes involved in SVD pathogenesis. Moreover, the latest achievements in the development of strategies to reduce the immunogenicity of BHV, such as data on immune compatibility of allogeneic material and the process of deriving low immunogenic biomaterial from genetically modified animals, decellularization of BHV, and the ways of slowing the process of degeneration are analyzed.

Bovine jugular vein conduit replacement after homograft degeneration in patients with tetralogy of Fallot: The results of re-redo cases.

This study aims to present our experience and results in terms of reconstruction with bovine jugular vein conduit in re-redo patients who developed severe homograft degeneration with pulmonary homograft valve replacement. Between May 2018 and May 2021, a total of 10 re-redo patients (4 males, 6 females; mean age: 16.5±3.0 years; range, 12 to 21 years) who underwent bovine jugular vein conduit replacement due to homograft degeneration were retrospectively analyzed. The clinical, pre-, intra-, and postoperative data of the patients were recorded. The mean age of the second operation (homograft replacement) was 8.5±3.8 (range, 4 to 14) years in the patients who underwent homograft replacement. No postoperative mortality was observed. When the pre- and postoperative findings were compared, the right ventricular outflow tract gradient, the degree of pulmonary and tricuspid regurgitation, and right ventricular dilatation were regressed (p<0.05). A significant improvement in the New York Heart Association functional class was observed in all patients after surgery. After tetralogy of Fallot corrective surgery, repetitive surgical interventions are inevitable due to pulmonary valve deterioration. Therefore, a bovine jugular vein conduit may be a good alternative for conduit preference after pulmonary homograft failure in re-redo cases.

Outcomes Following in Situ Reconstruction for Aortic Infection with the Neo-Aortoiliac System and Aortic Homograft

In situ reconstruction is one of the primary surgical options for primary aortic and graft and endograft infections. One institution's outcomes following aortic reconstruction with femoro-popliteal vein (i.e., the neo-aortoiliac system) and cryopreserved aortic allografts are described. A retrospective review was performed of any patient who underwent aortic reconstruction with femoropopliteal vein or cryopreserved aortic allograft from 2013-2022 at a single tertiary-care institution. Twenty four patients underwent in situ reconstruction with the neo-aortoiliac system or with cadaveric allograft for primary or secondary aortic infection from 2013-2022. Short-term (30-day) mortality remains low (3/24 or 12.5%) despite the high incidence of major postoperative complications that necessitated reintervention in 11/24 or 45.8% of the cohort, most often for recurrent intracavitary infection. Gram-negative and drug-resistant pathogens were the most commonly implicated organisms in recurrent intra-abdominal infection. Management of early allograft degeneration is also described with extra-anatomic bypass grafting, conduit/graft embolization, which is then followed by allograft explantation and wide surgical debridement. Despite low short-term (30-day) mortality, all-cause 1-year mortality remains elevated at 38.1% (8/21) in those with an adequate follow-up interval. In situ reconstruction for primary or secondary aortic infections results in excellent short-term patient outcomes but is characterized by a high incidence of reintervention and an elevated all-cause 1-year mortality.

Ross Operation in Pediatric Population: Impact of the Surgical Timing and the Native Pulmonary Diameter on the Outcome.

Aortic valve replacement early in life may be inevitable. Ross operation, until present day, remains the favorite surgical option in pediatrics with irreparable aortic valve disease. Nonetheless, the necessity for re-operation was always its principal limitation due to aortic valve failure or homograft degeneration. We present our 25years of experience in the pediatric population. From August 1994 until June 2018, 157 children below 18years underwent the Ross operation. This retrospective review aims at assessing the long-term outcomes, as well as the risk factors for re-operation after Ross procedure. Median age was 10.9years, of which seven patients were infants, 79 children, and 71 adolescents. The median follow-up time was 14years. Hospital mortality was 0.6%. Freedom from autograft re-operation for children was 96.7% and 94.1% at 10 and 20years, respectively; whereas for adolescents, it was 92.6% and 74.9% at 10 and 20years. For children, freedom from homograft re-operation was 92.5%, 83.5%, and 56.2% at 10, 15, and 20years; while for adolescents, it was 96.8%, 91.8%, and 86.7% at 10, 15, and 20years. Homograft size (p = 0.008) and childhood (p = 0.05) were risk factors for homograft re-operation. Pulmonary valve diameter > 24mm (p = 0.044) and adolescence (p = 0.032) were risk factors for autograft re-operation. Our experience demonstrated excellent early and late survival. While children have preferential outcomes concerning autograft re-operation, those who received a smaller homograft had a higher right-sided re-intervention incidence than adolescents. Pulmonary diameter > 24mm at surgery was an indicator of future autograft failure.

Serial assessment of early antibody binding to decellularized valved allografts.

ObjectivesDecellularized homograft valves (DHV) appear to elicit an immune response despite efficient donor cell removal.Materials and methodsA semiquantitative Dot-Blot analysis for preformed and new recipient antibodies was carried out in 20 patients following DHV implantation on days 0, 1, 7, and 28 using secondary antihuman antibodies. Immune reactions were tested against the implanted DHV as well as against the stored samples of 5 non-implanted decellularized aortic (DAH) and 6 pulmonary homografts (DPH).ResultsIn this study, 20 patients (3 female and 17 male patients) were prospectively included, with a median age of 18 years and an IQR of 12–30 years. Six patients received DPH and 14 received DAH. The amount of antibody binding, averaged for all patients, decreased on post-operative days 1 and 7 compared to pre-operative values; and on day 28, antibody binding reached close to pre-operative levels (16.8 ± 2.5 on day 0, 3.7 ± 1.9 on day 1, 2.3 ± 2.7 on day 7, and 13.2 ± 3.7 on day 28). In comparison with the results in healthy controls, there was a higher amount of antibody binding to DAH than to DPH. The mean number of arbitrary units was 18.4 ± 3.1 in aortic and 12.9 ± 4.5 in pulmonary DHV (p = 0.140). Male patients exhibited higher antibody binding to aortic DHV than female patients (19.5 ± 2.1 vs. 1.6 ± 6.7). The p-value calculation was limited, as only two female patients received DAH. There was no correlation between the amount of overall antibody binding to DHV with respect to donor age (Kruskal–Wallis test p = 0.550). DHV recipients with a sex mismatch to the donor showed significantly less antibody binding (6.5 ± 1.8 vs. 13.7 ± 1.8; p = 0.003). Our main finding was an increase in antibody binding in younger patients receiving decellularized aortic allografts. This increase was higher in patients with early degeneration signs but was not specific to the individual DHV implanted nor previous DHV implantation. Antibody binding toward explanted DHV was significantly increased in implicating antibody-mediated DHV degeneration.ConclusionSerial assessment of tissue-specific antibody binding revealed an increase in some patients within 4 weeks after surgery, who subsequently developed early signs of allograft degeneration. Further studies with larger sample sizes are needed to confirm the prognostic relevance of increased antibody activity in addition to targeted research efforts to identify the molecular agents triggering this type of antibody response.

Extrapulmonary tuberculosis - a diagnostic and therapeutic challenge

Allograft degeneration can be effectively treated with the use of covered stents. Transaxillary approach is an alternative to a compromised transfemoral access. Ipsilateral transradial access may increase the safety of a percutaneous transaxillary puncture.

The immediate meniscal allograft transplantation achieved better chondroprotection and less meniscus degeneration than the conventional delayed transplantation in the long-term.

The purpose of this study was to compare the long-term clinical and radiological outcomes between the immediate and delayed meniscus allograft transplantation (MAT). Nine menisci were transplanted immediately after total meniscectomy (immediate group, IM), and 10 menisci were delayed transplanted in patients with the median of 35months (range 9-92months) after total meniscectomy (delayed group, DE). Patient's subjective clinical outcomes including VAS, IKDC, Lysholm and Tegner scores as well as muscle strength measures were compared. Joint degeneration was evaluated by both radiographs to assess joint space width narrowing, Kellegren-Lawrence (KL) grade and MRI with T2 mapping sequences to quantitatively analyze both cartilage and meniscal allograft degeneration. The median follow-up time was 10.8years (range 10-14years). The IKDC (IM vs DE, 89.8 vs 80.9, n.s.) and Lysholm scores (IM vs DE, 87.7 vs 78.0, n.s.) were close in two groups, while the IM group showed slightly lower VAS (IM vs DE, 0.2 vs 1.5, p = 0.031), higher Tegner score (IM vs DE, 7 vs 3.5 p = 0.021) and better quadriceps muscle strength. The IM group had less joint space narrowing (IM vs DE, 0.35mm vs 0.71mm, n.s.), less KL grade progression (IM vs DE, 0.6 vs 1.7, p = 0.041) on radiographs and less chondral lesions development on MRIs (Cartilage Degeneration Index, IM vs DE, 252 vs 2038, p = 0.025). All meniscal grafts exhibited degeneration by showing grade 3 signal on MRI, and 4 (4/9) in the IM group and 8 (8/10) cases in the DE group. The T2 value of cartilage and meniscal allograft in the IM group was close to that of the healthy control and was significantly lower than that of the DE group. Compared to the conventional delayed MAT, the immediate MAT achieved better cartilage and meniscus protection in the long-term, while its superiority in patient-reported outcomes was limited. IV.

Cryopreserved aortic homografts for complex aortic valve or root endocarditis: a 28-year experience.

The aim of this study was to evaluate early- and long-term outcomes of cryopreserved aortic homograft (CAH) implantation for aortic valve replacement (AVR) or aortic root replacement (ARR) in patients with or without complex infective endocarditis. All adult patients undergoing AVR or ARR with CAH at our institution between January 1993 and July 2021 were included in the study. One hundred four patients, 75 males and 29 females, aged 59 ± 17 years, underwent AVR or ARR with CAH for infective endocarditis (n = 94, 90%) or aortic valve disease (n = 10, 10%). There were 33 (35%) native valve endocarditis and 61 (65%) prosthetic valve endocarditis, which were complicated by annular abscess in 77 (82%) patients, mitral valve endocarditis in 13 (14%) and tricuspid valve endocarditis in 13 (14%). The mean cardiopulmonary bypass time was 214 ± 80 min and the mean aortic cross-clamping time was 164 ± 56 min. There were 12 (12%) hospital deaths and 7 (7%) postoperative low cardiac output syndrome requiring extracorporeal membrane oxygenation in 4 patients and intra-aortic balloon pump in 3. Thirty-nine (42%) patients died during the follow-up (94% complete). The mean survival time was 13.9 ± 1.2 years. Twenty-five patients (26%) underwent late reoperation for aortic homograft degeneration (n = 17, 18%), homograft endocarditis (n = 6, 7%), homograft dehiscence (n = 1, 1%) and mitral valve regurgitation (n = 1, 1%). The mean survival free from reintervention was 15.7 ± 1.2 years. AVR or ARR with a CAH for complex endocarditis is associated with satisfactory hospital survival, considering the critical patient presentation at surgery, and excellent survival free from recurrent infection. Need for reoperation late after surgery is similar to other biological prostheses.

Manifestations of A Rare Italian Variant of Transthyretin Amyloidosis

Background Hereditary forms of amyloidosis are rare, but diagnosis will impact the treatment course of the patient and have lasting implications for other family members. Case 77 year old gentleman of Italian descent with a history of systolic heart failure (ejection fraction of 41%), hypertension, bilateral carpal tunnel syndrome, persistent atrial fibrillation (pulmonary vein isolation in 2013), history of mixed aortic valve disease status post 24 mm homograft presents with homograft degeneration. He subsequently underwent an aortic valve replacement with #23 CE valve and a 30 mm hemashield graft, mitral valve replacement and Left atrial appendage ligation. Left atrial appendage and mitral valve tissue were positive for amyloid on thioflavin S stain and immunohistochemical staining with strong reactivity to transthyretin. TTR genotyping confirmed an Italian variant c.252T>G; p.Phe84Leu (old nomenclature Phe64Leu). A technetium pyrophosphate (TcPYP) scan was not suggestive of cardiac amyloidosis (H/CL ratio G; p.Phe84Leu mutation. He has been referred to neuromuscular clinic for further evaluation and potential initiation of a medical therapy. Conclusion The two brothers highlight some of the difficulty associated with the diagnosis of amyloidosis given its variable clinical phenotype. Additionally, it is known that myocardial uptake in bone compound scintography scans can be falsely negative for unclear reasons in patients with c.252T>G; p.Phe84Leu mutations. Lastly, the isolated left atrial uptake on TcPYP scans should be further investigated as an early manifestation of cardiac amyloidosis.

Analysis of Failure-mechanisms of Cryopreserved Vascular Allografts in Peripheral Reconstructions

Introduction: Cryopreserved vascular allografts represent a well known option in the treatment of vascular infections. Moreover several groups also suggested their use in case of patients with no suitable veins requiring an infragenicular bypass. The aim of the present study was to evaluate the failure mechanisms of cryopreserved allografts in peripheral reconstructions in a cohort of patients treated at a single Institution. Methods: We retrospectivly analized a prospectively collected database comprising all patients undergoing a peripheral reconstruction with cryopreserved arterial or venous allografts between August 2010 and January 2019. The composite result of graft failure (occlusion + degeneration + any graft-related complication) was calculated as a primary endpoint. In case of reintervention hystological analysis of a segment of allograft was performed. Results: A total of 20 patients [mean age 66.1 +/- 10.3 yy, M 66% (12/18)] underwent 25 vascular in-situ reconstruction with cryopreserved arterial or venous allografts. Indication for treatment was infection of a previous prosthetic graft in 12 cases, critical limb ischemia in 8, allograft degeneration in 3 and mycotic pseudoaneurym in 2. Type of reconstruction are reassumed in table I Table I. Type o.... In 17 cases an arterial allograft was used (11 single segment, 6 multiple segments) and in 8 cases a vein allograft (6 single segment, 2 multiple segments). At 30 days there were 3 deaths (1 myocardial infarction, 1 rupture of thoracic aortic aneurysm, 1 anastomotyc disrupture) with 2 additional deaths during follow up (1 drug overdose, 1 intestinal ischemia). Mean follow-up was 31 months (min 1 - max 81) with no patients lost to follow up. Overall graft failure occurred in 7 cases (28%) (3 aneurysmal degenerations, 2 occlusions, 2 anastomotyc disrupture) with reintervention with allograft performed in 4 cases. There was no statistical difference in the incidence of the composite endpoint between venous and arterial grafts [OR 0.71 (0.098 - 5.2), p 1], between patients with infection and without infection [OR 1.8 (0.26 - 12), p 0.66] and between single and multiple segments grafts [OR 2.8 (0.42 - 2.9), p 0.34], although occlusions occurred only in veins (2/8, 25%) and aneurismal degeneration only in arterial allografts (3/17, 17%). Hystological analysis was available for 5 allografts: 2 anastomotyc disruptures showing wall necrosis due to infection, 3 aneurysmal degenerations showing a chronic flogistic pattern suggestive of immune-mediated rejection. Kaplan-Meier estimates showed an overal 26% of freedom from graft failure at 60 months, with no difference between patients with and without infection and venous and arterial allografts (Logrank test p: 019 and 0.26 respectively). Conclusion: In our series the failure rate of allografts was not low, although their use was limited to very high risk situations. Accurate follow up is mandatory as the risk of aneurysmal degeneration is not negligible with arterial allografts, although they seem to offer a better patency rate compared to veins. Immune-mediated rejection plays a role in aneurysmal degeneration while uncontrollable infection greatly hinders the early postoperative outcome.Table IType of peripheral reconstruction with allografts and type of allografts usedType of ReconstructionN (%)Type of allografts (N)Composite axillo-femoral bypass1 (4%)Single Arterial (1)Femoral tibial bypass4 (16%)Multiple Arterial (2) Single Venous (1) Multiple Venous (1)Femoral femoral crossover bypass2 (8%)Single Arterial (2)Below knee femoral popliteal bypass5 (20%)Single Arterial (1) Multiple Arterial (3) Single Venous (1)Above knee femoral popliteal bypass2 (8%)Single Arterial (1) Single Venous (1)Iliac femoral bypass3 (12%)Single Arterial (2) Multiple Arterial (1)Femoral truncal bypass2 (8%)Single Venous (1) Multiple Venous (1)Common femoral reconstruction4 (16%)Single Arterial (3) Single Venous (1)Bypass of a dilated segment of a previous allograft2 (8%)Single Arterial (2) Open table in a new tab Disclosure: Nothing to disclose

Recurrent rapid homograft degeneration and extensive calcification

Recurrent rapid homograft degeneration and extensive calcification

Primary arthroplasty in healed osteoarticular allograft in patients with history of primary femoral bone tumors

BackgroundRoughly 25–35% of patients who are treated with osteoarticular allograft for primary bone sarcomas or aggressive benign bone tumors require surgery in the long-term due to degenerative changes of the articular surface of the allograft. There are three established methods of reconstruction for this complication; a total hip arthroplasty (THA) or total knee arthroplasty (TKA) in the retained osteoarticular allograft, a proximal or distal endoprosthesis after removal of the allograft, and an allograft-prosthesis composite (APC). The aims of this study are 1) to determine the rate of complication and failure of THA/TKA in healed femoral allograft; 2) to compare the methods of revision for allograft degeneration; and 3) to compare the use of arthroplasty in healed allograft to that of arthroplasty in native bone. MethodsWe included all patients with primary bone sarcomas and locally aggressive primary benign bone tumors treated between 1984 and 2014 with an osteoarticular allograft followed by any subsequent arthroplasty technique as described above. Complications and reasons for failure are described following the classification of Henderson et al. Failure was defined as any complication leading to removal of the initial treatment construct. Failure rates of these groups were compared to primary arthroplasty in a live host bone (Control Group). ResultsComplications happened in 25 (61.0%) of the patients with a THA/TKA in the retained allograft, of these, 24 (58.5%) experienced failure, the most common being structural failure/type III (14, 58.3%). Thirteen patients (81.3%) with an endoprosthesis after removal of the allograft experienced complications, all of whom failed. The most common failure modes were aseptic loosening/type II (4, 30.8%) and infection/type IV (5, 38.5%). Complications in patients with an APC were experienced by 12 (85.7%) patients, 11 (78.6%) of whom failed. The most common failure mode was infection/type IV (4, 36.4%). Significantly (p < 0.001) fewer failures were observed in the control group compared to patients with an arthroplasty in a healed allograft. ConclusionsWe found no significant difference in the outcome of treating patients with allograft and subsequent degenerative bone disease with a THA/TKA in a retained allograft, an endoprosthesis after removal of the allograft, or a primary APC, although infection is a significantly greater cause of failure in the latter two. Primary arthroplasty in healed allografts is a less extensive surgery than removing the allograft and shows comparable complication and failure rates. Level of evidenceLevel III, Therapeutic Study.

Right ventricular outfl ow tract revalvulation using the Melody Valve: The next frontier

Congenital heart lesions with abnormal right ventricular outfl ow tract anatomy will require early surgical intervention. Re-intervention rates in these patients are high due to homograft degeneration. Until recently, surgery was the only treatment option for right ventricular outfl ow tract dysfunction. Percutaneous pulmonary valve implantation has been introduced as a new therapeutic alternative to prolong conduit life span and to reduce surgical re-intervention rates. Short- and mid-term results have been favourable and showed that it is a safe and effective therapy. These are reviewed with emphasis on the Melody valve.

Dysfunctional pulmonary artery conduit and co-existing large pseudoaneurysm: well-suited for a percutaneous approach with the Melody valve?

Pseudoaneurysm formation is a rare but potentially life-threatening complication after surgical repair of congenital heart disease. We present a boy with truncus arteriosus communis 14 years after homograft placement in pulmonary position. On follow-up, he presented progressive chronic homograft degeneration. Moreover, a large pseudoaneurysm in the right ventricular outflow tract was surprisingly depicted. We opted for a two-stage interventional approach.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-3273-3) contains supplementary material, which is available to authorized users.

57. Aortic valve replacement with sutureless valve and mitral valve repair in patient with infected aortic homograft

The approach of implanting aortic sutureless valve inside the calcific homograft is suitable in redo surgery especially if associated with mitral valve surgery. Aortic valve replacement in patients who have undergone previous aortic root replacement with an aortic homograft remains a technical challenge because of homograft degeneration and the need for a redo Bentall operation. We report a case of redo aortic valve replacement (valve in valve) with a sutureless valve and mitral valve repair by miniband annuloplasty in a female patient aged 64 years old who underwent aortic valve replacement with homograft 14 years ago and presented by sever aortic valve regurge and sever mitral valve regurge because of infective endocarditis. This technique allows rapid aortic valve replacement in a heavily calcified aortic root. It also avoids aortic valve size affection after mitral valve repair by ordinary methods especially in patients with small aortic annulus. This technique is particularly suitable in redo procedures for homograft degeneration, it avoids performing a redo Bentall operation with its known problems as well as to avoid patient prosthesis mismatch.

Over 20 years experience with aortic homograft in aortic valve replacement during acute infective endocarditis.

Despite the controversy, the aortic homograft is supposedly the best option in acute infective endocarditis (AIE), due to its resistance to reinfection. However, the technical complexity and the risk of structural deterioration over time have limited its utilization. The aim of this study was to evaluate the long-term results of aortic homograft for the treatment of infective endocarditis in our institution with particular attention to predictors of survival and homograft reoperation. The cohort includes 112 patients who underwent aortic valve replacement with an aortic homograft for AIE between January 1990 and December 2014. Fifteen patients (13.4%) died during the first 30 days after the operation. Two patients were lost to follow-up after discharge from the hospital; therefore, 95 patients were available for long-term analysis. The median duration of follow-up was 7.8 years (IQR 4.7-17.6). Five patients (5.3%) suffered a recurrence of infective endocarditis (1 relapse and 4 new episodes). Sixteen patients (16.8%) were reoperated for structural valve degeneration (SVD; n = 14, 87.5%) or for infection recurrence (n = 2, 12.5%). Freedom from homograft reoperation for infective endocarditis or structural homograft degeneration at 10 and 15 years postoperatively was 86.3 ± 5.5 and 47.3 ± 11.0%, respectively. For patients requiring homograft reoperation, the median interval to reintervention was 11.6 years (IQR 8.3-14.5). Long-term survival was 63.6% (95% CI 52.4-72.8%) and 53.8% (95% CI 40.6-65.3%) at 10 and 15 years, respectively. The use of aortic homograft in acute aortic valve endocarditis is associated with a remarkably low risk of relapsing infection and very acceptable long-term survival. The risk of reoperation due to SVD is significant after one decade especially in young patients. The aortic homograft seems to be ideally suited for reconstruction of the aortic valve and cardiac structures damaged by the infective process especially in early surgery.

Cryopreserved Arterial Allografts and ABO and Rhesus Compatibility

Arterial cryopreserved allografts are conduit of choice for arterial bypass in case of infection. They are sometimes submitted to accelerated degeneration: stenosis, thrombosis, or aneurysmal evolution. We hypothesized that ABO group and Rhesus compatibility could play a role in arterial cryopreserved allograft complications. Patients who benefit from allograft bypass from 2006 to 2011 were retrospectively compared, regarding ABO or rhesus compatibility and irregular agglutinins. Seventy-two patients were included. Regarding ABO mismatch, there was no difference in terms of death (51% vs. 43%, P=0.820), thrombosis (25% vs. 32%, P=0.78), rupture (9% vs. 0%, P=0.247), stenosis (3% vs. 12%, P=0.331), aneurysmal degeneration (16% vs. 12%, P=1), and 5years of secondary patency rate (34% vs. 39%, P=0.141). There was also no difference regarding Rhesus mismatch. Allograft degeneration does not seem to be related to ABO mismatch. This degeneration could be related to another way of immunogenicity, particularly Human Leukocyte Antigen mismatch, and needs further exploration.

Pericardial Tube Grafts: Bail-out Option or Routine Concept for Thoracic Aortic Infections?

Objectives: Thoracic aortic infections are a deadly disease. Homografts are considered the gold standard to replace the affected aorta. However, availability is limited and long term results may be limited by homograft degeneration. Pericardial tube grafts have been suggested as an alternative. Biological valved pericardial conduits are commercially available. We reviewed our data on pericardial tube graft implantations.