miR-124-3p downregulates EGR1 to suppress ischemia-hypoxia reperfusion injury in human iPS cell-derived cardiomyocytes.

Ischemic heart diseases are a major global cause of death, and despite timely revascularization, heart failure due to ischemia-hypoxia reperfusion (IH/R) injury remains a concern. The study focused on the role of Early Growth Response 1 (EGR1) in IH/R-induced apoptosis in human cardiomyocytes (CMs). Human induced pluripotent stem cell (hiPSC)-derived CMs were cultured under IH/R conditions, revealing higher EGR1 expression in the IH/R group through quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB). Immunofluorescence analysis (IFA) showed an increased ratio of cleaved Caspase-3-positive apoptotic cells in the IH/R group. Using siRNA for EGR1 successfully downregulated EGR1, suppressing cleaved Caspase-3-positive apoptotic cell ratio. Bioinformatic analysis indicated that EGR1 is a plausible target of miR-124-3p under IH/R conditions. The miR-124-3p mimic, predicted to antagonize EGR1 mRNA, downregulated EGR1 under IH/R conditions in qRT-PCR and WB, as confirmed by IFA. The suppression of EGR1 by the miR-124-3p mimic subsequently reduced CM apoptosis. The study suggests that treatment with miR-124-3p targeting EGR1 could be a potential novel therapeutic approach for cardioprotection in ischemic heart diseases in the future.

Using the DNA Integrity Number to Analyze DNA Quality in Specimens Collected from Liquid-Based Cytology after Fine-Needle Aspiration of Breast Tumors and Lesions.

INTRODUCTION: Cancer genome analysis using next-generation sequencing requires adequate and high-quality DNA samples. Genomic analyses were conventionally performed using formalin-fixed paraffin-embedded sections rather than cytology samples such as cell block or smear specimens. Specimens collected from liquid-based cytology (LBC) have the potential to be sources of high-quality DNA suitable for genetic analysis even after long-term storage. METHODS: We collected breast tumor/lesion fractions from 92 residual LBC specimens using fine-needle aspiration (FNA) biopsy, including breast carcinoma (1 invasive carcinoma and 4 ductal carcinomas in situ), papillomatous lesion (5 intraductal papillomas), and fibroepithelial lesion (19 phyllodes tumors and 53 fibroadenomas) samples, and others (1 ductal adenoma, 1 hamartoma, 1 fibrocystic disease, and 7 unknown). DNA was extracted from all samples and subjected to DNA integrity number (DIN) score analysis. RESULTS: Average DIN score collected from 92 LBC specimens was significantly higher score. In addition, high-quality DNA with high DIN values (7.39 ± 0.80) was successfully extracted more than 12 months after storage of residual LBC specimens. CONCLUSION: Residual LBC specimens collected from FNA of the breast were verified to carry high-quality DNA and could serve as an alternate source for genetic analysis.

Surgical treatment for a child with traumatic ventricular septal rupture and ventricular aneurysm.

A five-year-old boy was diagnosed with the ventricular septal rupture and ventricular aneurysm after blunt chest trauma in child abuse. Because of the intractable heart failure, he underwent operation in subacute period. Postoperative course was uneventful. The blunt cardiac injury in children can be caused by mild trauma and can be lethal. Surgical intervention should be considered when the clinical condition is unstable.

Pleurodesis using OK-432 for persistent pleural effusion after cardiac surgery in the neonatal period or early infancy.

OBJECTIVE: To evaluate the efficacy of pleurodesis using OK-432 after cardiac surgery in the neonatal period or early infancy. METHODS: We retrospectively reviewed the data of 11 consecutive patients who underwent cardiac surgery in the neonatal period or early infancy and pleurodesis using OK-432 for persistent postoperative pleural effusion in two institutions. RESULTS: The median age at surgery was 8 days (interquartile range [IR], 2-18) with a body weight of 2.84 kg (IR, 2.30-3.07). The maximum amount of pleural drainage before pleurodesis was 94.7 (IR, 60.2-107.7) ml/kg/day. Pleurodesis was initiated at postoperative day 20 (IR, 17-22) and performed in bilateral pleural spaces in seven patients and unilateral in four. The median numbers of injection were 4 (IR, 3-6) times per patient and 3 (IR, 2-3) times per pleural space. In 10 patients, pleural effusion was decreased effectively, and drainage tubes were removed without reaccumulation within 15 (IR, 12-28) days after initial pleurodesis. However, in one patient, with severe lymphedema, pleural effusion was uncontrollable, resulting in death due to sepsis. Adverse events were observed in nine patients; temporal deterioration of lung compliance and arterial blood gas occurred in two, insufficient drainage requiring new chest tube(s) in five, temporal atrial tachyarrhythmia in one, and lymphedema in four. CONCLUSIONS: Pleurodesis using OK-432 is effective and reliable for persistent postoperative pleural effusion in neonates and early infants. Most of the complications, which derived from inflammatory reactions, were temporary and controllable. However, severe lymphedema is difficult to control.

Novel operative technique for Scimitar syndrome: Posterior flap technique.

Various surgical techniques have been reported for Scimitar syndrome, because of the heterogenous anatomy of the disease. We developed a novel surgical method to repair Scimitar syndrome, in which, a new pulmonary venous route is constructed behind the inferior vena cava using autologous flaps of the inferior vena cava and the interatrial septum. An adult case of Scimitar syndrome was repaired by this method with good results.

The first successful case of ABO-incompatible living-donor lobar lung transplantation following desensitization therapy.

ABO-incompatible (ABO-I) living-donor lobar lung transplantation (LDLLT) was successfully performed in a 14-year-old girl who suffered from bronchiolitis obliterans due to graft-versus-host disease following hematopoietic stem cell transplantation. In the ABO-I LDLLT procedure, the blood type O patient received a right lower lobe donated from her blood type B father and a left lower lobe donated from her blood type O mother. Desensitization therapy, using rituximab, immunosuppressants, and plasmapheresis, was implemented for 3 weeks prior to transplantation to reduce the production of anti-B antibodies in the recipient and prevent acute antibody-mediated rejection after ABO-I LDLLT.

Influence of the bronchus on the vascular growth of major aortopulmonary collateral arteries.

OBJECTIVES: Patients with major aortopulmonary collateral arteries (MAPCAs) often require additional surgical or catheter intervention after unifocalization (UF) due to stenosis and poor growth. We hypothesized that the UF design influences vascular growth; assessment was based on the passing route related to the bronchus. METHODS: We enrolled 5 patients with pulmonary atresia (PA), ventricular septal defect and MAPCA who underwent UF and subsequent definitive repair at our institute from 2008 to 2020. Angiography and computed tomography scans were routinely performed before surgical intervention to clarify pulmonary circulation and the relationships between MAPCAs and the bronchus, which revealed peculiar MAPCAs directed to the pulmonary hilum passing behind the bronchus (defined as retro-bronchial MAPCAs; rbMAPCAs). Vascular growth of rbMAPCAs, non-rbMAPCAs and the native pulmonary artery were assessed using the angiograms before and after repair. RESULTS: The angiogram before UF [age 42 (24-76) days, body weight 3.2 (2.7-4.2) kg] showed that the diameter of the original unilateral PA, rbMAPCA and non-rbMAPCA was 19.95 ± 6.65, 20.72 ± 5.36 and 20.29 ± 7.42 mm/m2, respectively (P = 0.917). UF was completed in a single-stage with the placement of modified Blalock-Taussig shunt through median sternotomy at the age of 1.6 (1.0-2.5) months. Angiograms performed 3.0 (1.0-10.0) years after UF completion demonstrated a smaller rbMAPCA diameter at peri-bronchial region (3.84 ± 2.84 mm/m2) compared to the native unilateral PAs (16.11 ± 5.46 mm/m2, P < 0.0001) and non-rbMAPCA (10.13 ± 4.44 mm/m2, P = 0.0103). CONCLUSIONS: RbMAPCAs tend to be stenosed at the point where they cross the bronchus and emerge in the middle mediastinum after in situ UF.

Comparison of living-donor lobar lung transplantation and cadaveric lung transplantation for pulmonary hypertension.

OBJECTIVES: Living-donor lobar lung transplantation (LDLLT) is a life-saving procedure for critically ill patients with various lung diseases, including pulmonary hypertension (PH). However, there are concerns regarding the development of heart failure with pulmonary oedema after LDLLT in which only 1 or 2 lobes are implanted. This study aimed to compare the preoperative conditions and postoperative outcomes of LDLLT with those of cadaveric lung transplantation (CLT) in PH patients. METHODS: Between 2008 and 2021, 34 lung transplants for PH, including 12 LDLLTs (5 single and 7 bilateral) and 22 bilateral CLTs, were performed. Preoperative variables and postoperative outcomes were retrospectively compared between the 2 procedures. RESULTS: Based on the preoperative variables of less ambulatory ability (41.7% vs 100%, P < 0.001), a higher proportion of World Health Organization class 4 (83.3% vs 18.2%, P < 0.001) and higher mean pulmonary artery pressure (74.4 vs 57.3 mmHg, P = 0.040), LDLLT patients were more debilitated than CLT patients. Nevertheless, hospital death was similar between the 2 groups (8.3% vs 9.1%, P > 0.99, respectively). Furthermore, the 5-year overall survival rate was similar between the 2 groups (90.0% vs 76.3%, P = 0.489). CONCLUSIONS: Although LDLLT patients with PH had worse preoperative conditions and received smaller grafts than CLT patients, LDLLT patients demonstrated similar perioperative outcomes and prognoses as CLT patients. LDLLT is a viable treatment option for patients with PH.

Outcome and growth of lobar graft after pediatric living-donor lobar lung transplantation.

BACKGROUND: Living-donor lobar lung transplantation (LDLLT) remains a life-saving option for pediatric patients with respiratory failure. However, the long-term survival and post-transplant quality of adult lobar grafts transplanted into children are unknown. Therefore, this study aimed to evaluate the outcomes of pediatric LDLLT and post-transplant graft growth. METHODS: We retrospectively reviewed the prospectively collected clinical data of 25 living-donor lung transplantations performed in 24 pediatric recipients aged ≤17 years. The annual pulmonary function test data and computed tomography scans of 12 recipients, followed up for >5 years without significant complications, were used to evaluate growth in height, graft function, and radiological changes. The Kaplan-Meier method and simple linear regression were performed for analysis. RESULTS: Bilateral lower lobe transplantation was performed in 12 patients, unilateral lower lobe transplantation in 12, and bilateral middle lobe transplantation in 1. The median volumetric size matching at transplantation was 142% (range, 54%-457%). The 5- and 10-year overall survival rates were 87.7% and 75.1༅, respectively. Chronic lung allograft dysfunction occurred in 2 patients. During a median follow-up of 6 years, the median increases in height and vital capacity were 14.4% (range, 0.80%-43.5%) and 58.5% (range, 6.7%-322%), respectively. Graft weight was positively correlated with graft volume (r2=0.622, p<0.001) after the graft volume exceeded the original lobar volume in the donor. CONCLUSIONS: This study shows that pediatric LDLLT offers satisfactory long-term survival, with the growth of mature adult lobes transplanted into growing children.

Living-donor segmental lung transplantation for pediatric patients.

OBJECTIVE: The preset study evaluated the outcome of living-donor segmental lung transplantation for pediatric patients. METHODS: Between August 2009 and May 2021, we performed living-donor segmental lung transplantation in 6 critically ill pediatric patients, including 1 patient on a ventilator alone and another patient on a ventilator and extracorporeal membrane oxygenation (ECMO). There were 4 male and 2 female patients, with a median age of 7 years (range, 4-15 years) and a median height of 112.7 cm (range, 95-125.2 cm). The diagnoses included complications of allogeneic hematopoietic stem cell transplantation (n = 4) and pulmonary fibrosis (n = 2). All patients received bilateral lung transplantation under cardiopulmonary bypass. A basal segment and a lower lobe were implanted in 3 patients, and a basal segment and an S6 segment were implanted in the other 3 patients. In 2 patients, the right S6 segmental graft was horizontally rotated 180° and implanted as the left lung. RESULTS: Among the 9 segmental grafts implanted, 7 functioned well after reperfusion. Two rotated S6 segmental grafts became congestive, with 1 requiring graft extraction and the other venous repair, which was successful. There was 1 hospital death (14 days) due to sepsis and 1 late death (9 years) due to leukoencephalopathy. The remaining 4 patients are currently alive at 9 months, 10 months, 1.3 years, and 1.9 years. CONCLUSIONS: Living-donor segmental lung transplantation was a technically difficult but feasible procedure with acceptable outcomes for small pediatric patients with chest cavities that were too small for adult lower lobe implantation.

A prospective analysis of two studies that used the 5-mm interval slices and 5-mm margin-free method for ipsilateral breast tumor recurrence after breast-conserving surgery without radiotherapy.

BACKGROUND: Breast-conserving surgery with radiotherapy is one of standard treatments for early breast cancer. However, it is regarded as an option to treat elderly patients with small hormone receptor-positive breast cancer with breast-conserving surgery and hormone therapy without radiotherapy. We conducted two sequential prospective studies to examine the feasibility of breast-conserving surgery without radiotherapy since 2002 and present the results. PATIENTS AND METHODS: Primary female breast cancer patients who fulfilled the strict eligibility criteria were prospectively enrolled in two sequential studies named WORTH 1 and 2. The surgical materials were sliced in 5-mm intervals and all slices were examined microscopically. Postoperative radiotherapy was not allowed, but tamoxifen or anastrozole was administered for 5 years. Ipsilateral breast tumor recurrence (IBTR)-free survival was the primary outcome. RESULTS: The data of the two studies were combined (N = 321). The median follow-up period for IBTR was 94 months (4-192 months). Only three patients were treated with adjuvant chemotherapy. The 5- and 10-year IBTR-free rates were 97.0% and 90.5%, respectively. The age at operation and PR status affected IBTR rates independently. When we calculated IBTR-free rates of patients who were 65 years of age or older at the time of surgery and had PR-positive tumors, the 5- and 10-year IBTR rates were both 98.4%. CONCLUSIONS:  Our "5-mm-thick slice and 5-mm free-margin" method may be effective to select patients who can be treated by breast-conserving surgery and hormone therapy without radiotherapy.

Tricuspid valve repair with papillary muscle approximation for congenital tricuspid valve regurgitation due to tricuspid valve dysplasia.

We experienced a case of a 1-year-old female with congenital tricuspid valve regurgitation caused by tricuspid valve dysplasia. The anterior and septal leaflets were particularly dysplastic, and leaflet tethering was observed. The anterior papillary muscle was approximated to the interventricular septum, and a commissural edge-to-edge suture was inserted on the anteroseptal commissure. Tricuspid valve regurgitation improved to be trivial after surgery and has not worsened 1 year later. Papillary muscle approximation could be one of the feasible reparative techniques for congenital tricuspid valve regurgitation.

[A Case of Triple Negative Breast Cancer with Successful Control of Recurrent Disease Activity for More than Ten Years].

A woman in her 70s underwent mastectomy plus axillary lymph node excision(Bt plus Ax)in December 2011 for left breast cancer classified as pT2N1M0, pStage ⅡB. The tumor was identified as an invasive ductal carcinoma(IDC), neural/ glial antigen 2(NG2), pT2(35 mm), INF γ, ly2, v0, g+, f+, s+, extensive intraductal component(EIC)-negative, ICT- positive, NCAT-positive, n(4/18), estrogen receptor(ER)-negative, progesterone receptor(PgR)-negative, human epidermal growth factor receptor 2(HER2)-negative, Ki-67 30-40%. Postoperative adjuvant fluorouracil plus epirubicin HCl plus cyclophosphamide(FEC)plus paclitaxel(PTX)therapy was administered. The patient refused to undergo postoperative radiation therapy. Two years after the surgery, she was diagnosed as having a lung metastasis and local disease recurrence. Biopsy of the local recurrent lesion revealed the same histopathological diagnosis as before. Capecitabine was selected for treatment of the recurrent lesion. After 2 years of capecitabine treatment, the response was rated as progressive disease (PD). At this time, eribulin mesylate was selected, along with intensity-modulated radiation therapy(IMRT). This resulted in disappearance of the tumor on imaging. However, considering that the histological findings did not suggest complete response(CR)and that the tumor was triple-negative(TN), we adopted a strategy of continuing the drug therapy at reduced dose level. With this strategy, the disease activity could be successfully controlled for 6.5 years. Subsequently, liver metastasis was detected, and the drug was switched to vinorelbine ditartrate(a drug with less non-hematological toxicity). Meanwhile, a breast cancer susceptibility gene(BRCA)analysis was performed in January 2021, which was negative. Subsequently, in September 2021, we obtained a positive result for PDL1-SP142 and negative result for 22C3. About half a year later, ie, in October 2021(11 years after the surgery), we detected an increase in the size of the liver metastasis and selected atezolizumab and nab-PTX for treatment. Applicable regimens of drug therapy are still available at present and drug therapy has been continued based on a discussion and mutual understanding of the adverse reactions, etc. with the patient. Few reports have been published concerning long-term survivors among TN breast cancer cases.

A novel approach for the endothelialization of xenogeneic decellularized vascular tissues by human cells utilizing surface modification and dynamic culture.

Decellularized xenogeneic vascular grafts can be used in revascularization surgeries. We have developed decellularization methods using high hydrostatic pressure (HHP), which preserves the extracellular structure. Here, we attempted ex vivo endothelialization of HHP-decellularized xenogeneic tissues using human endothelial cells (ECs) to prevent clot formation against human blood. Slices of porcine aortic endothelium were decellularized using HHP and coated with gelatin. Human umbilical vein ECs were directly seeded and cultured under dynamic flow or static conditions for 14 days. Dynamic flow cultures tend to demonstrate higher cell coverage. We then coated the tissues with the E8 fragment of human laminin-411 (hL411), which has high affinity for ECs, and found that Dynamic/hL411showed high area coverage, almost reaching 100% (Dynamic/Gelatin vs Dynamic/hL411; 58.7 ± 11.4 vs 97.5 ± 1.9%, P = 0.0017). Immunostaining revealed sufficient endothelial cell coverage as a single cell layer in Dynamic/hL411. A clot formation assay using human whole blood showed low clot formation in Dynamic/hL411, almost similar to that in the negative control, polytetrafluoroethylene. Surface modification of HHP-decellularized xenogeneic endothelial tissues combined with dynamic culture achieved sufficient ex vivo endothelialization along with prevention of clot formation, indicating their potential for clinical use as vascular grafts in the future.

Pioglitazone-incorporated microspheres targeting macrophage polarization alleviates cardiac dysfunction after myocardial infarction.

OBJECTIVES: Excessive and chronic inflammation after a myocardial infarction (MI) is associated with left ventricular remodelling and impaired cardiac function. Among inflammatory cells, macrophages play a critical role in polarizing proinflammatory M1 or the reparative M2 subtype. Pioglitazone (PGZ) is reported to regulate macrophage polarization to the M2 subtype. Our goal was to validate the therapeutic effects and the mechanisms of PGZ utilizing a drug delivery system. METHODS: Poly L-lactic-co-glycolic acid microspheres (MS) incorporating PGZ were prepared. To validate the therapeutic potential of PGZ-MS, Sprague-Dawley rats were subjected to permanent left coronary artery ligation to induce an MI. Placebo-MS (100 µg) or PGZ-MS (100 µg) was injected to the infarct region just after induction. Cardiac function and size were assessed by echocardiography. At 28 days after surgery, the rats were sacrificed, and the excised hearts were evaluated histologically. RESULTS: Sustained release of PGZ from the PGZ-MS was confirmed in vitro. PGZ-MS significantly rehabilitated cardiac dysfunction after an MI (fractional shortening: MI vs MI+placebo-MS vs MI+PGZ-MS, 24.4 ± 1.1 vs 24.3 ± 1.6 vs 32.2 ± 1.4%; P = 0.0035) with reverse remodelling. Immunohistochemical analyses revealed that PGZ-MS enhanced macrophage polarization (ratio of M2 subtype: 0.39 ± 0.03 vs 0.42 ± 0.02 vs 0.54 ± 0.02; P = 0.0004) and attenuated apoptosis of cardiomyocytes in the ischaemic border zone. CONCLUSIONS: We confirmed macrophage polarization by sustained release of PGZ, which resulted in amelioration of adverse left ventricular remodelling and cardiac dysfunction. Drug delivery system-based macrophage polarization might serve as a promising strategy in cardiac regenerative therapy for ischaemic heart disease. (241 words).

New strategy to resume and taper epoprostenol after lung transplant for pulmonary hypertension.

OBJECTIVE: The perioperative outcome of lung transplantation (LTx) for patients with severe pulmonary hypertension (PH) remains poor due to the occurrence of primary graft dysfunction (PGD) from left ventricular failure. We hypothesized that tapering pretransplant use of epoprostenol rather than abrupt discontinuation after transplantation might improve perioperative outcomes. METHODS: We performed 23 LTxs for patients with severe PH who received epoprostenol therapy from 2008 until 2021. In the discontinued group (n = 6), epoprostenol was discontinued after the establishment of extracorporeal circulation. In the tapered group (n = 17), epoprostenol was discontinued and resumed after reperfusion, and then gradually tapered over the following 2 weeks. We assessed survival, bleeding, blood transfusion, re-opening of the chest, oxygenation, PGD score, extracorporeal membrane oxygenation (ECMO) requirement for recovery after transplantation, and duration of mechanical ventilation. RESULTS: The PGD score was significantly lower in the tapered group than in the discontinued group at 0 h, 24 h, and 48 h after LTx. In addition, the discontinued group required longer mechanical ventilation than the tapered group. Delayed chest closure and post-transplant ECMO use for recovery occurred significantly more frequently in the discontinued group. CONCLUSIONS: To resume and taper epoprostenol administration after reperfusion in patients with severe PH may be a valuable new strategy associated with better perioperative outcomes.

Evaluations for surrounding tissue incorporation after implantation of synthetic vascular prostheses in animal models.

Incorporation of surrounding tissues after implantation of synthetic vascular prostheses potentially varies in accordance with implanted prostheses. To evaluate post-implant tissue incorporation, we examined surgical, histological and ultrastructural findings after implantation in animal models. Three types of commercially available prostheses were tested (Gelweave™; Group G, J Graft SHIELD NEO®; Group J and Triplex®; Group T). Prostheses were implanted into Sprague-Dawley rats subcutaneously or sutured on abdominal aorta of Japanese white rabbits. The tissues were surgically examined for adhesion and were subjected to histological evaluations for cellular and tissue infiltration and ultrastructural observations by scanning electron microscopy (SEM). Group G exhibited less tendency in adhesion formation in early phase (rat: G vs J, P < 0.0001; G vs T, P < 0.0001/rabbit: G vs J, P < 0.0001; G vs T, P = 0.059). In late phase, Group J showed highest adhesion (rat: G vs J, P = 0.0004; J vs T, P = 0.015/rabbit: G vs J, P = 0.0015; J vs T, P = 0.0044). In group G, a gap was observed between implants and surrounding tissues forming capsulation, whereas other groups exhibited tissue infiltration inside of the implants wall which were also confirmed by SEM. The tissue permeation toward the implants and adhesion was positively correlated (P < 0.0001). Surrounding tissue conformation varied in accordance with the type of prostheses. It is desirable to elucidate characteristics of each prosthesis to select suitable grafts for each patient to achieve a better surgical outcome.

[One-stage Radical Surgery for Aortoesophageal Fistula after Graft Replacement of Descending Aorta].

A 31-year-old woman was referred to our institution because of aortoesophageal fistula (AEF) six months after the descending aortic replacement for acute aortic dissection. We operated one-stage repair of the AEF. Thoracoscopic esophagectomy was firstly performed in prone position from right thoracic cavity, and then the esophagus was reconstructed with gastric conduit via posterior mediastinal route with omental flap. Secondly, graft replacement of the descending aorta using lateral oblique straight incision was performed and the graft was covered with omental flap simultaneously. The postoperative course was uneventful, and she started oral intake on the 13th day after surgery. Although the one-stage surgery for the AEF is highly invasive, it could be a good option for selected cases.

In vivo recellularization of xenogeneic vascular grafts decellularized with high hydrostatic pressure method in a porcine carotid arterial interpose model.

Autologous vascular grafts are widely used in revascularization surgeries for small caliber targets. However, the availability of autologous conduits might be limited due to prior surgeries or the quality of vessels. Xenogeneic decellularized vascular grafts from animals can potentially be a substitute of autologous vascular grafts. Decellularization with high hydrostatic pressure (HHP) is reported to highly preserve extracellular matrix (ECM), creating feasible conditions for recellularization and vascular remodeling after implantation. In the present study, we conducted xenogeneic implantation of HHP-decellularized bovine vascular grafts from dorsalis pedis arteries to porcine carotid arteries and posteriorly evaluated graft patency, ECM preservation and recellularization. Avoiding damage of the luminal surface of the grafts from drying significantly during the surgical procedure increased the graft patency at 4 weeks after implantation (P = 0.0079). After the technical improvement, all grafts (N = 5) were patent with mild stenosis due to intimal hyperplasia at 4 weeks after implantation. Neither aneurysmal change nor massive thrombosis was observed, even without administration of anticoagulants nor anti-platelet agents. Elastica van Gieson and Sirius-red stainings revealed fair preservation of ECM proteins including elastin and collagen after implantation. The luminal surface of the grafts were thoroughly covered with von Willebrand factor-positive endothelium. Scanning electron microscopy of the luminal surface of implanted grafts exhibited a cobblestone-like endothelial cell layer which is similar to native vascular endothelium. Recellularization of the tunica media with alpha-smooth muscle actin-positive smooth muscle cells was partly observed. Thus, we confirmed that HHP-decellularized grafts are feasible for xenogeneic implantation accompanied by recellularization by recipient cells.