Aortic Homograft Research Articles

Aortic Valve Replacement in Adult Patients with Decellularized Homografts: A Single-Center Experience.

decellularized aortic homografts (DAH) represent a promising alternative for aortic valve replacement in young adults due to their low immunogenicity and thrombogenicity. Herein, we report our midterm, single-center experience in adult patients with non-frozen DAH from corlife. safety, durability, and hemodynamic performance were evaluated according to current guidelines in all consecutive patients who had received a DAH at our center since 03/2016. seventy-three (mean age 47 ± 11 years, 68.4% (n = 50) male) patients were enrolled. The mean diameter of the implanted DAH was 24 ± 2 mm. Mean follow-up was 36 ± 27 months, with a maximum follow-up of 85 months and cumulative follow-up of 215 years. No cases of stenosis were observed, in four (5.5%) cases moderate aortic regurgitation occurred, but no reintervention was required. No cases of early mortality, non-structural dysfunction, reoperation, valve endocarditis, or thrombosis were observed. Freedom from bleeding and thromboembolic events was 100%; freedom from re-intervention was 100%; survival was 98.6% (n = 72). early and mid-term results showed low mortality and 100% freedom from reoperation, thromboembolic events, and bleeding at our center. However, in order for this novel approach to be established as a valid alternative to aortic valve replacement in young patients, long-term data are required.

Technique and Outcomes of Concomitant Aortic and Caval Resection and Reconstruction for Retroperitoneal Tumors

Major vascular involvement is often considered a contraindication to resection of malignant tumors, but in highly selected patients it can be performed safely, with results that are highly dependent upon the tumor biology. Resection of both the aorta and inferior vena cava (IVC) is a rare undertaking, requiring both favorable tumor biology and a patient fit for a substantial surgical insult; nevertheless, it provides the possibility of a cure. Patients requiring resection and reconstruction of both the aorta and IVC from 2009 through 2019 at two university medical centers were included. Patient characteristics, operative technique, and outcomes were retrospectively collected. We identified nine patients, all with infrarenal reconstruction or repair of the aorta and IVC. All cases were performed with systemic heparinization and required simultaneous aortic and caval cross-clamping for tumor resection. No temporary venous or arterial bypass was used. Since arterial reperfusion with the IVC clamped was poorly tolerated in one patient, venous reconstruction was typically completed first. Primary repair was performed in one patient, while eight required replacements. In two patients, aortic homograft was used for replacement of both the aortoiliac and iliocaval segments in contaminated surgical fields. In the remaining six, Dacron was used for arterial replacement; either Dacron (n=2) or PTFE (n=4) were used for venous replacement. Patients were discharged after a median stay of 8 days (range: 5-16). At median follow up of 17 months (range 3-79 months), two patients with paraganglioma and one patient with Leydig cell carcinoma had cancer recurrences. Venous reconstructions occluded in three patients (38%), though symptoms were minimal. One patient presented acutely with a thrombosed iliac artery limb and bilateral common iliac artery anastomotic stenoses, treated successfully with thrombolysis and stenting. Patients with tumor involving both the aorta and IVC can be successfully treated with resection and reconstruction. En bloc tumor resection, restoration of venous return before arterial reconstruction, and most importantly, careful patient selection, all contribute to positive outcomes in this otherwise incurable population.

Preliminary results in tracheal replacement using stented aortic matrices for primary extensive tracheal cancer.

Recent studies have demonstrated the feasibility and favorable long-term results of tracheobronchial replacement using stented cryopreserved aortic allografts. We propose to investigate the outcomes of this emerging technique in the subgroup of patients with extensive tracheal cancer. This study was based on 13 patients with primary extensive tracheal cancer extracted from the prospective registry TRITON-01 (ClinicalTrials.gov Identifier: NCT04263129), which included 40 patients in total. We analyzed early and late outcomes in this subset of patients. From March 2019 to September 2022, 13 patients were included in the study. There were 9 female and 4 male patients, with a mean age of 53.9years [36-71 years]. They had tracheal replacement for extended adenoid cystic carcinoma (n=11), squamous cell carcinoma (n=1), and mucoepidermoid carcinoma (n=1). A venovenous extracorporeal membrane oxygenation was used in the 6 last cases. The mean length of resection was 81 mm [50-120 mm]. There was no 30-day postoperative mortality. A complete resection (R0) was achieved in 11 patients. The main late complications consisted of tracheal granulomas related to the stent and requiring repeated bronchoscopies (n=9), pneumonia (n=3), airway infection (n=1), bronchoesophageal fistula (n=1), mechanical stent obstruction requiring change (n=2), and mediastinitis treated by antibiotics, drainage, and omentoplasty (n=1). With a maximal follow-up of 3years and 7months, cancer recurrence was observed in 2 patients. All patients were alive at last follow-up except 2 (84.6%). Airway replacement using stented CAA represents a feasible and promising solution for extensive tracheal cancer.

A Literature Review on the Use of Aortic Allografts in Modern Cardiac Surgery for the Treatment of Infective Endocarditis: Is There Clear Evidence or Is It Merely a Perception?

Infective valve endocarditis is caused by different pathogens and 60% of those involve the aortic valve with valve failure. Although S. aureus is recognized as the most frequently isolated causative bacterium associated with IE in high-income countries, Gram-positive cocci nevertheless play a crucial role in promoting infection in relation to their adhesive matrix molecules. The presence of pili on the surface of Gram-positive bacteria such as in different strains of Enterococcus faecalis and Streptococcus spp., grants these causative pathogens a great offensive capacity due to the formation of biofilms and resistance to antibiotics. The indications and timing of surgery in endocarditis are debated as well as the choice of the ideal valve substitute to replace the diseased valve(s) when repair is not possible. We reviewed the literature and elaborated a systematic approach to endocarditis management based on clinical, microbiological, and anatomopathological variables known to affect postoperative outcomes with the aim to stratify the patients and orient decision making. From this review emerges significant findings on the risk of infection in the allograft used in patients with endocarditis and no endocarditis etiology suggesting that the use of allografts has proved safety and effectiveness in patients with both pathologies.

Surgical treatment of aortic root abscess: 10-year single center experience

The issue of optimal surgical scope in patients with aortic root abscess due to infective endocarditis remains open, since there are different strategies and interventional methods. In addition, the guidelines do not give preference to any particular type of surgical intervention and recommend an individual approach to each situation. The study included 25 patients with aortic root abscess due to aortic valve infective endocarditis. The most frequently performed surgical intervention in patients was the Ross procedure (n=12, 48%). Eight (32%) patients of the center underwent aortic homograft root replacement. Combined surgery was performed in 7 (28%) patients as follows: 3 (12%) patients — interventions on the mitral valve (all patients underwent mitral valve repair due to mitral valve involvement in abscess), 3 (12%) — coronary artery bypass grafting, 1 (4%) — ascending aortic replacement due to dilatation. Five- and ten-year survival after surgical treatment of patients with aortic root abscess was 86,9% and 78,6%, respectively. There was no reintervention and recurrence of infective endocarditis in the long-term period.

Surgical treatment of aortic root abscess: 10-year single center experience

The issue of optimal surgical scope in patients with aortic root abscess due to infective endocarditis remains open, since there are different strategies and interventional methods. In addition, the guidelines do not give preference to any particular type of surgical intervention and recommend an individual approach to each situation. The study included 25 patients with aortic root abscess due to aortic valve infective endocarditis. The most frequently performed surgical intervention in patients was the Ross procedure (n=12, 48%). Eight (32%) patients of the center underwent aortic homograft root replacement. Combined surgery was performed in 7 (28%) patients as follows: 3 (12%) patients — interventions on the mitral valve (all patients underwent mitral valve repair due to mitral valve involvement in abscess), 3 (12%) — coronary artery bypass grafting, 1 (4%) — ascending aortic replacement due to dilatation. Five- and ten-year survival after surgical treatment of patients with aortic root abscess was 86,9% and 78,6%, respectively. There was no reintervention and recurrence of infective endocarditis in the long-term period.

The use of an aortic allograft in infection of an aortic prosthesis in a patient with a multi-storey lesion of the arterial bed of the lower extremities

The article presents a clinical case of treatment of patient K, 61 years old, with previously performed aorto-femoral bifurcation bypass surgery for critical lower limb ischemia. 6 months after the initial surgery, the patient developed thrombosis of the right arm of the prosthesis. After another 3 months, a persistent subfebrile body temperature appeared, multiple fistula passages formed with the release of pus in the areas of postoperative scars on the hips. Infection of a synthetic prosthesis was diagnosed. A decision was made to perform repeated surgical intervention in the volume of abdominal aortic reprosthetics with a cadaveric allograft. The surgery was performed at the clinic of the Faculty of Surgery of SamSMU: removal of the bifurcation synthetic prosthesis; rehabilitation of the prosthesis bed; reprosthetics of the aorta with vascular aortic allograft; endarterectomy from the deep artery of the thigh on both sides; bifurcation aorto-femoral reprosthetics; femoral-popliteal bypass with allograft on the right. The postoperative period was uneventful. Healing of wounds on the hips by secondary tension due to marginal skin necrosis. Critical limb ischemia was stopped. The patient was discharged on the 20th day in a satisfactory condition.CONCLUSION. The use of allografts makes it possible to perform reprosthetics of the abdominal aorta in case of infection of synthetic prosthesis and simultaneous reconstruction of the femoral-popliteal segment.

Association between postoperative exposure to fine particulate matter and patency of the right ventricle–pulmonary artery conduit

BackgroundAmbient air pollution is a leading risk factor for cardiovascular diseases. No study has investigated the association between exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM2.5) and the prognosis of patients undergoing surgery for the right ventricle–pulmonary artery (RV-PA) conduit. MethodsFrom 2013 to 2020, patients with six complicated congenital heart defects who had undergone surgery for the RV–PA conduit were selected. Four conduit materials were used: bovine jugular vein graft (BJV), pulmonary homograft (PHG), aortic homograft (AHG), and handmade tri-leaflet expanded polytetrafluoroethylene (ePTFE) conduit. Telephone interviews were used to confirm the postoperative address of patients. The monthly average PM2.5 concentration was obtained from the ChinaHighPM2.5 dataset using the place of residence of patients. By comparing findings of echocardiography undertaken before patients' return to their residence and during re-examination, we defined an increase in the trans-conduit peak velocity of ≥1.5 m/s as the study endpoint. ResultsWe enrolled 232 patients. Compared with BJV conduits, homografts (AHGs and PHGs) (0.052 (95 % CI = 0.005–0.558), P = 0.015) and ePTFE conduits (0.009 (95 % CI = 0.002–0.054), P < 0.001) were protective factors. The cumulative monthly PM2.5 concentration (10 μg/m3) was a risk factor (1.014 (95 % CI = 1.001–1.026), P = 0.028). Winter experience was a risk factor (1.971 (95 % CI: 1.021–3.804), P = 0.043). In the subgroup analysis, Spearman correlation analysis indicated BJV conduits (r = 0.680, P < 0.001), PHGs (r = 0.559, P = 0.020), and AHGs (r = 0.745, P = 0.021) had medium-to-high positive correlations between the cumulative PM2.5 concentration and change in the conduit velocity. For ePTFE, the correlation was weak and not significant (r = 0.222, P = 0.073). ConclusionsPostoperative exposure to PM2.5 affects the patency of biologic prosthetic conduits (especially xenografts). The increase in the velocity of the ePTFE conduit is not associated with PM2.5 exposure, and is a suitable material for patients living in areas with high pollutant concentrations.

Meta-Analysis of Single-Cell RNA-Seq Data Reveals the Mechanism of Formation and Heterogeneity of Tertiary Lymphoid Organ in Vascular Disease.

Tertiary lymphoid organs (TLOs) are ectopic lymphoid organs developed in nonlymphoid tissues with chronic inflammation, but little is known about their existence in different types of vascular diseases and the mechanism that mediated their development. To take advantage of single-cell RNA sequencing techniques, we integrated 28 single-cell RNA sequencing data sets containing 5 vascular disease models (atherosclerosis, abdominal aortic aneurysm, intimal hyperplasia, isograft, and allograft) to explore TLOs existence and environment supporting its growth systematically. We also searched Medline, Embase, PubMed, and Web of Science from inception to January 2022 for published histological images of vascular remodeling for histological evidence to support TLO genesis. Accumulation and infiltration of innate and adaptive immune cells have been observed in various remodeling vessels. Interestingly, the proportion of such immune cells incrementally increases from atherosclerosis to intimal hyperplasia, abdominal aortic aneurysm, isograft, and allograft. Importantly, we uncovered that TLO structure cells, such as follicular helper T cells and germinal center B cells, present in all remodeled vessels. Among myeloid cells and lymphocytes, inflammatory macrophages, and T helper 17 cells are the major lymphoid tissue inducer cells which were found to be positively associated with the numbers of TLO structural cells in remodeled vessels. Vascular stromal cells also actively participate in vascular TLO genesis by communicating with myeloid cells and lymphocytes via CCLs (C-C motif chemokine ligands), CXCL (C-X-C motif ligand), lymphotoxin, BMP (bone morphogenetic protein) chemotactic, FGF-2 (fibroblast growth factor-2), and IGF (insulin growth factor) proliferation mechanisms, particularly for lymphoid tissue inducer cell aggregation. Additionally, the interaction between stromal cells and immune cells modulates extracellular matrix remodeling. Among TLO structure cells, follicular helper T, and germinal center B cells have strong interactions via TCR (T-cell receptor), CD40 (cluster of differentiation 40), and CXCL signaling, to promote the development and maturation of the germinal center in TLO. Consistently, by reviewing the histological images from the literature, TLO genesis was found in those vascular remodeling models. Our analysis showed the existence of TLOs across 5 models of vascular diseases. The mechanisms that support TLOs formation in different models are heterogeneous. This study could be a valuable resource for understanding and discovering new therapeutic targets for various forms of vascular disease.

Three Decades of Experience with Aortic Prosthetic Valve Endocarditis.

The objective of this study was to evaluate early and long-term outcomes of patients with aortic prosthetic valve endocarditis (a-PVE) treated with a prosthetic aortic valve (PAV), prosthetic valved conduit (PVC), or cryopreserved aortic homograft (CAH). A total of 144 patients, 115 male and 29 female, aged 67 ± 12 years, underwent surgery for a-PVE at our institution between 1994 and 2021. Median time from the original cardiac surgery was 1.9 [0.6-5.6] years, and 47 (33%) patients developed an early a-PVE. Of these patients, 73 (51%) underwent aortic valve replacement (AVR) with a biological or mechanical PAV, 12 (8%) underwent aortic root replacement (ARR) with a biological or mechanical PVC, and 59 (42%) underwent AVR or ARR with a CAH. Patients treated with a CAH had significantly more circumferential annular abscess multiple valve involvement, longer CPB and aortic cross-clamping times, and needed more postoperative pacemaker implantation than patients treated with a PAV. No difference was observed in survival, reoperation rates, or recurrence of IE between patients treated with a PAV, a PVC, or a CAH. CAHs are technically more demanding and more often used in patients who have extensive annular abscess and multiple valve involvement. However, the use of CAH is safe in patients with complex a-PVE, and it shows excellent early and long-term outcomes.

Tracheal Replacement with Cryopreserved Aortic Homograft Maintained by Custom 3D Printed Plastic External Splint

Tracheal Replacement with Cryopreserved Aortic Homograft Maintained by Custom 3D Printed Plastic External Splint

The Use of the Cryopreserved Aortic Homograft for Aortic Valve Replacement: Is It Still an Option?

The indications for cryopreserved allografts in aortic valve replacement are still debatable. We aim to identify factors influencing early and long-term durability of the aortic homograft and to define subgroups of patients with an improved long-term quality of life, survival, and freedom from structural valve degeneration (SVD). We evaluated our series of 210 patients who underwent allograft implantation with a retrospective cohort study design over a period of 20 years. Endpoints were overall mortality, cardiac mortality related to SVD, the incidence of SVD, reoperation, and a composite endpoint comprising major adverse cardiac and cerebrovascular events (MACCEs), which includes cardiac death both related and not related to SVD, subsequent aortic valve surgery, new or recurrent infection of implanted allograft, recurrent aortic regurgitation, rehospitalization for heart failure, an increase in New York Heart Association (NYHA) class of ≥1, or cerebrovascular events. The primary indication for surgery was endocarditis (48%), which was also a predisposing factor for increased cardiac mortality. Overall mortality was 32.4% with a 27% incidence of SVD and mortality associated with SVD of 13.8%. Reoperation occurred in 33.8% and MACCEs in 54.8%. Long-term NYHA functional class and echocardiographic parameters improved over time. Statistical analysis demonstrated that root replacement technique and adult age were protective factors for SVD. We found no statistically significant difference in the clinical outcomes analyzed between women of childbearing age who had children after surgery and the rest of the women. The cryopreserved allograft is still a valid option in aortic valve replacement, providing acceptable durability and clinical outcomes with optimal hemodynamic performance. SVD is influenced by the implantation technique. Women of childbearing age might have additional benefits from this procedure.

Long-Term Outcomes After Right Ventricular Outflow Tract Conduit Placement

Objective: Our aim was to report on the long-term outcomes of patients who underwent RV-PA conduit placement at our institute. Materials and Methods: We retrospectively reviewed 407 RV-PA conduit placements from January 1997 to December 2018. The primary outcomes were freedom from and risk factor(s) for conduit re-operation. The secondary outcomes were survival, freedom from conduit dysfunction and conduit-related catheter intervention. Results: Of all the included patients, 209 were male (51.4%) and the median age at the operation was nine years (IQR 6, 18 years). The most commonly used conduit types were bovine jugular vein conduit (125, 30.7%), pulmonary homograft (122, 30.0%), and aortic homograft (76, 18.7%). The median follow-up time was 5.1 years (IQR 0.9, 9.2 years). The overall survival was 92.2% at 5 years. Freedom from re-operation was 95.4% and 84.2%, at 5 and 10 years. Factors related to conduit reoperation were age at operation less than 1 year, diagnosis rather than pulmonary atresia or stenosis, conduit size less than 18 mm, and conduit z-score greater than 3 (all p&lt;0.01). In multivariate analysis, a significant contributing factor for re-operation was small conduit size (13 mm or smaller; HR 6.87 (95%CI 2.36, 20.01); p&lt;0.001, 14–17 mm; HR 3.20 (95%CI 1.28, 8.00); p=0.013). Freedom from conduit dysfunction was 84.4% and 61.6% at 5 and 10 years. Freedom from conduit intervention was 94.4% and 89.3% at 5 and 10 years. Conclusion: Our study showed that patients had excellent survival with acceptable freedom from re-operation despite deteriorated conduit function. Small conduit size is associated with re-operation.

A-146 TRACHEAL RECONSTRUCTION IN ADVANCED THYROID CANCER USING STENTED AORTIC MATRICES

Abstract Background Extensive airway involvement in thyroid cancer is associated with poor prognosis and constitutes one of the main causes of mortality. Airway replacement based on the implantation of stented aortic matrices emerges as a novel tool in the treatment of primary tracheobronchial malignancies and tracheal involvement in advanced thyroid cancer. Methods We conducted a retrospective cohort study including patients who had tracheal replacement with a stented aortic matrix for advanced thyroid cancer with (crico)-tracheal invasion at our centre. Cryopreserved aortic allografts were used for tracheal reconstruction. To prevent airway collapse, silicone stents were placed inside the grafts. The bioprostheses were covered with local muscle flaps. No immunosuppressive therapy was required. Results Over 5 years, 10 patients underwent tracheal replacement with stented aortic matrices. 2 patients underwent a concomitant thyroidectomy with neck dissection and 8 had thyroidectomy prior to airway replacement and presented with recurrence. A R0 resection was achieved in all patients. There were no cases of perioperative mortality. At a median follow-up of 19 months, 8 patients were alive and breathing and speaking normally. 2 patients died of causes unrelated to the graft. De novo generation of pseudocartilage was observed within the grafts. Conclusion Tracheal resection using stented aortic allografts is a simple and efficient technique of tracheal replacement that is becoming part of standard care at our institution. This approach allows for a R0 resection in advanced thyroid malignancies considered thus far as non-resectable.

Aortic Valve Reinterventions after Ozaki: Clinical Case Series from Four Centers

Introduction. One of surgical methods for treatment of aortic valve (AV) pathology is Aortic Valve Neocuspidalization Ozaki procedure (AVNeo). Thus, according to the latest systematic review, freedom from reoperation within one, three, five years after AVNeo was 98%, 97% and 96%. Available references provide few descriptions of reoperations after AVNeo. Aim. To analyze the immediate results of AV reinterventions after AVNeo. Materials and methods. In the medium term, reinterventions after AVNeo were necessary for 11 patients (4.3%). The age of patients ranged from 26 to 69 years. 11 patients who underwent surgery included 6 males and 5 females. Four patients had class III-IV CHF, according to NYHA classification. Three patients had previously been operated on for infective endocarditis (IE), and five patients had bicuspid aortic valve. The duration of follow-up, from AVNeo surgery to reinterventions, ranged from 3 to 43 months. Results and discussion. All patients underwent an isolated AV intervention. The main causes of dysfunction were IE (six patients) and leaflet rupture in the commissural area (five patients). Seven patients underwent aortic valve replacement with mechanical valves, one patient — with aortic homograft valve, one patient — with tissue valve and two patients underwent valve repair. In the early postoperative period, one patient had bleeding with the development of cardiac tamponade and one patient had a haemorrhagic stroke. No patients had ARF, perioperative myocardial damage, sternal infection or permanent pacemaker implantation. Two patients died during the hospital period. Conclusions. AV reinterventions are associated with a high incidence of complications and deaths. Therefore, prevention of IE and commissure enhancement should reduce the frequency of repeated interventions, which is to be confirmed by prospective studies in large cohorts of patients.

Aortic allografts for surgical treatment of prosthetic valve endocarditis

Background: Prosthetic valve endocarditis, the most severe form of infective endocarditis, occurs in 1-6% of patients with valve prostheses and is still associated with poor prognosis and high in-hospital mortality.Objective: To assess outcomes of allograft aortic root replacement in patients with prosthetic valve endocarditis.Methods: The retrospective analysis included adult patients with prosthetic valve endocarditis, who underwent allograft aortic root replacement between 2011 and 2022.Results: Of 15 study patients, early infective endocarditis was found in 60.0% of the cases. The most common cause was Staphylococcus aureus (26.7%). Early mortality was 13.3%. Thromboembolic events occurred in 2 patients (13.3%). The median follow-up period was 48.5 (6-140) months. Late death was reported in 1 patient. The 5-year survival rate was 79.0%. One patient had recurrent infective endocarditis. Two patients underwent reintervention: one for a proximal anastomotic pseudoaneurysm and another one for structural degeneration of the allograft. Five-year freedom from reintervention was 91.7%.Conclusion: Due to the high rate of the freedom from recurrent infective endocarditis, allograft aortic root replacement is an effective treatment for patients with prosthetic valve endocarditis. Received 7 November 2022. Revised 9 December 2022. Accepted 20 December 2022. Funding: The study was supported by the grant of the president of the Russian Federation (No. 075-15-2022-823). Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: A.V. Bogachev-ProkophievData collection and analysis: A.V. Karadzha, A.N. Pivkin, A.S. ZalesovStatistical analysis: R.M. Sharifulin, A.V. AfanasyevDrafting the article: R.M. Sharifulin, A.V. AfanasyevCritical revision of the article: A.V. Bogachev-Prokophiev, S.I. ZheleznevFinal approval of the version to be published: A.V. Bogachev-Prokophiev, R.M. Sharifulin, S.I. Zheleznev, A.V. Karadzha, A.V. Afanasyev, A.N. Pivkin, A.S. Zalesov

Application of aortic allograft in trachea transplantation

The use of tracheal implants for tracheal reconstruction remains a challenge in thoracic medicine due to the complex structure of the trachea in mammalian organisms, including smooth muscles, cartilage, mucosa, blood vessels, cilia, and other tissues, and the difficulty in achieving tracheal regeneration using implants from either allografts or synthetic biomaterials. This project used the Lee-Sung strain pig, a swine breed local to Taiwan, as the experimental subject. The aorta of the pig was harvested, decellularized to form the scaffold, and transplanted into the trachea of allogeneic pigs together with growth factors. Postoperative physiological function and tissue changes were observed. The postoperative physiological parameters of the LSP were monitored, and they were sacrificed after a certain period to observe the pathological changes in the tracheal epithelial cells and cartilages. Overall, six LSP tracheal transplantations were performed between March 4, 2020, and March 10, 2021. These included aortic patch anastomosis for pig 1 and aortic segmental anastomosis for pigs 2-6. The shortest and longest survival periods were 1 day and 147 days, respectively. Excluding the pig that survived for only 1 day due to a ruptured graft anastomosis, all other subjects survived for over 1 month on average. In this study, we grafted a decellularized porcine aorta into a recipient pig with a tracheal defect. We found cryopreservation of the allogeneic aorta transplantation was a feasible and safe method for the management of airway disease, and immunosuppressants were unnecessary during the treatment course.

Impact of storage time prior to cryopreservation on mechanical properties of aortic homografts

Optimal time spans in homograft procurement are still debatable among tissue banks and needs to be further investigated. Cell viability decreases at longer preparation intervals, but the effect on collagen and elastic fibers has not been investigated to the same extent. These fibers are of importance to the homograft elasticity and strength. The objective of this study was to analyze the mechanical properties of homograft tissue at different time spans in the procurement process. Ten aortic homografts were collected at the Tissue Bank in Lund. Twelve samples were obtained from each homograft, cryopreserved in groups of three after 2–4 days, 7–9 days, 28–30 days, and 60–62 days in antibiotic decontamination. Mechanical testing was performed with uniaxial tensile tests, calculating elastic modulus, yield stress and energy at yield stress. Two randomly selected samples were assessed with light microscopy. Procurement generated a total of 120 samples, with 30 samples in each time group. Elastic modulus and yield stress was significantly higher in samples cryopreserved after 2–4 days (2.7 MPa (2.5-5.0) and 0.78 MPa (0.68-1.0)) compared to 7–9 days (2.2 MPa (2.0-2.6) and 0.53 MPa (0.46–0.69)), p = 0.008 and 0.011 respectively. Light microscopy did not show any difference in collagen and elastin at different time spans. There was a significant decrease in elastic modulus and yield stress after 7 days of decontamination at 4 °C compared to 2–4 days. This could indicate some deterioration of elastin and collagen at longer decontamination intervals. Clinical significance of these findings remains to be clarified.

Surgical management of large tracheoesophageal fistula in infants after button battery ingestion.

In recent years, an increase in severe and even fatal outcomes related to oesophageal or airway button battery (BB) ingestion by infants and small children has been reported. Extensive tissue necrosis caused by lodged BB can lead to major complications, including tracheoesophageal fistula (TEF). In these instances, best treatment remains controversial. While small defects may warrant a conservative approach, surgery often remains inevitable in highly complex cases with large TEF. We present a series of small children that underwent successful surgical management by a multidisciplinary team in our institution. This is a retrospective analysis of n = 4 patients <18 months undergoing TEF repair from 2018 to 2021. Surgical repair under extracorporeal membrane oxygenation (ECMO) support was feasible in n = 4 patients by reconstructing the trachea with decellularized aortic homografts that were buttressed with pedicled latissimus dorsi muscle flaps. While direct oesophageal repair was feasible in 1 patient, 3 required esophagogastrostomy and secondary repair. The procedure was completed successfully in all 4 children with no mortality and acceptable morbidity. Tracheo-oesophageal repair after BB ingestion remains challenging and is associated with major morbidity. Bioprosthetic materials in conjunction with the interposition of vascularized tissue flaps between trachea and oesophagus appear to be a valid approach to manage severe cases.

Aortic root allograft reoperations

ObjectiveTo investigate outcomes after aortic root allograft reoperation, identify risk factors for morbidity and mortality, and describe practice evolution since publication of our 2006 allograft reoperation study. MethodsFrom January 1987 to July 2020, 602 patients underwent 632 allograft-related reoperations at Cleveland Clinic: 144 before 2006 (early era, which suggested radical explant was superior to aortic-valve-replacement-within-allograft [AVR-only]), and 488 from 2006 to present (recent era). Indications for reoperation were structural valve deterioration in 502 (79%), infective endocarditis in 90 (14%), and nonstructural valve deterioration/noninfective endocarditis in 40 (6.3%). Reoperative techniques included radical allograft explant in 372 (59%), AVR-only in 248 (39%), and allograft preservation in 12 (1.9%). Perioperative events and survival were assessed among indications, techniques, and eras. ResultsOperative mortality by indication was 2.2% (n = 11) for structural valve deterioration, 7.8% (n = 7) in those with infective endocarditis, and 7.5% (n = 3) for nonstructural valve deterioration/noninfective endocarditis, and by surgical approach 2.4% (n = 9) after radical explant, 4.0% (n = 10) for AVR-only, and 17% (n = 2) for allograft preservation. Operative adverse events occurred in 4.9% (n = 18) of radical explants and 2.8% (n = 7) of AVR-only procedures (P = .2). Patients undergoing radical explants received larger valves than those undergoing AVR-only (median, 25 vs 23 mm). ConclusionsAortic root allograft reoperations present a technical challenge but can be performed with low mortality and morbidity. Radical explant offers outcomes similar to AVR-only while allowing for implant of larger prostheses. Increasing experience with allograft reoperations has permitted excellent outcomes; thus, risk of reoperation should not dissuade surgeons from using allografts for invasive aortic valve infective endocarditis and other indications.