Spinal Cord Injury Risk in Open Repair for Descending Thoracic and Thoracoabdominal Aneurysm.

Objective: In open repair for descending thoracic aortic aneurysm (DTAA) or thoracoabdominal aortic aneurysm (TAAA), the influence of re-interventions on spinal cord injury (SCI) remains unclear. This study evaluated the relationships between re-interventions, atherosclerosis, and SCI. Methods: We retrospectively reviewed 78 patients who underwent open surgical repair for DTAA or TAAA between April 2011 and May 2023. The associations of SCI with (i) re-interventions with a history of endovascular therapy and graft replacement and (ii) atherosclerotic factors, including monocyte count, triglyceride levels (TG), and intra-aortic plaques, were examined. Results: The rates of SCI complications and 30-day mortality were both 3.8% (3/78). There was no significant difference between the incidence of SCI in the re-intervention and first-time intervention groups (p >0.90). However, patients with protruding plaque on computed tomography (CT) were more affected by SCI than those without (13.3% vs. 1.6%, p = 0.034). Univariate analysis revealed that SCI was associated with increased monocyte count, TG, protruding plaques on CT, and intraoperative blood loss. Conclusion: Re-interventions for DTAA and TAAA showed no association with the development of SCI under appropriate protective measures. The implicated risk factors may be atherosclerosis factors such as elevated monocyte count, TG, and protruding plaques on CT.

What Is the Optimal Antithrombotic Therapy for Valsalva Thrombus Following Transcatheter Aortic Valve Replacement?

Thrombus formation between the native sinus of Valsalva and the implanted transcatheter heart valve is a rare complication that may be associated with an increased risk for thrombotic complications. This paper presents the course of 3 cases with Valsalva thrombus, with a focus on the management of antithrombotic therapy.

Repair of a right coronary artery rupture with perforated right ventricle following spontaneous pseudoaneurysm: a case report.

BACKGROUND: Following the rupture of a coronary artery, a patient's condition usually deteriorates rapidly due to cardiac tamponade. A pseudoaneurysm due to a coronary artery rupture is rare; however, when a spontaneous coronary artery pseudoaneurysm occurs without tamponade, it creates a fistula in the right ventricle, often requiring surgical repair. CASE PRESENTATION: This report describes the case of a 68-year-old man who presented with chest discomfort after a 12-day course of antibiotic treatment for bacteremia. Following coronary angiography, echocardiography, and enhanced computed tomography, he was diagnosed with a right coronary artery pseudoaneurysm accompanied with perforation of the right ventricle. Severe adhesions were observed during emergency surgery surrounding the entire heart. The patient presented with risk factors for coronary artery disease, including hypertension and smoking history. His coronary artery was severely calcified due to end-stage renal failure requiring dialysis; thus, a covered stent could not fit inside the arterial lumen. Consequently, coronary artery bypass grafting to the right coronary artery and right ventricle repair were performed. Unfortunately, the patient died postoperatively due to sepsis from intestinal translocation. This rare development was hypothesized to be an incidental result of the combination of severe post-inflammatory adhesions, extensive coronary artery calcification, and rupture of the calcification crevices. CONCLUSIONS: In the case of a severe post-inflammatory response, shock without cardiac tamponade may require further scrutiny by assuming the possibility of inward rupture. For patients in poor condition, two-stage surgical treatment might be considered after stabilization with a covered stent.

Relationship between false lumen morphology and entry tear in acute type A aortic dissection.

OBJECTIVES: This study aimed to investigate the relationship between false lumen morphology and the size, aortic segment and position of the entry tear for acute type A aortic dissection. METHODS: The records of patients who underwent emergency operation for acute type A aortic dissection in our institution between April 2011 and May 2022 were examined. Data regarding size, location and position of the entry tear and preoperative computed tomography findings were reviewed. The relationship of these variables with false lumen morphology was examined and retrospectively compared according to tear size. RESULTS: Of 243 cases, characteristics of the entry tear, visualized during surgery, were confirmed in 134 cases (age = 70.9 ± 12.6 years, male = 45.5%). Tear sizes at different aortic segments were not significantly different (P = 0.376). Tears posterior to the lesser curvature were significantly smaller than those anterior to the greater curvature (P = 0.004). A thrombosed false lumen was associated with a significantly smaller tear size and position on the posterior to the lesser curvature side in aortic cross-section (all P < 0.001). Multivariate analysis showed that tear size, the presence of re-entry and tear position anterior to the greater curvature were independent predictors of a patent false lumen. CONCLUSIONS: In acute type A aortic dissection, larger tear size, the presence of re-entry and tear position anterior to the greater curvature are risk factors for a patent false lumen. Although the results of this study are valid only for patients in whom intimal tears were detected during aortic surgery, this trend may provide information for pathophysiology of the disease.

Current Status of Off-Pump Coronary Artery Bypass.

PURPOSE: Off-pump coronary arterial bypass grafting (OPCAB) has become a common practice for coronary artery bypass grafting (CABG) in Japan, with approximately 65% CABG procedures currently being performed using OPCAB. However, it is unclear whether OPCAB is superior in terms of associated mortality, incidence of complications, graft patency rate, and long-term outcomes compared with conventional CABG (CCABG). METHODS: Literature consideration was performed, mainly based on observational studies involving large samples and randomized controlled trials (RCTs). RESULTS: Many RCTs indicated that the acute-phase and long-term mortality rates were comparable between CCABG and OPCAB or that OPCAB was inferior to CCABG. In contrast, many observational studies indicated that OPCAB was superior to CCABG. CONCLUSION: CABG is a delicate procedure, the outcomes of which vary in accordance with the patient's condition as well as the level of expertise of the associated institution and surgeon. In the future, we hope that reports will emerge with excellent results, including long-term results, from Japanese institutions experienced in performing OPCAB.

Stimulation of Caveolin-1 Signaling Improves Arteriovenous Fistula Patency.

Objective- Arteriovenous fistulae (AVF) are the most common access created for hemodialysis; however, many AVF fail to mature and require repeated intervention, suggesting a need to improve AVF maturation. Eph-B4 (ephrin type-B receptor 4) is the embryonic venous determinant that is functional in adult veins and can regulate AVF maturation. Cav-1 (caveolin-1) is the major scaffolding protein of caveolae-a distinct microdomain that serves as a mechanosensor at the endothelial cell membrane. We hypothesized that Cav-1 function is critical for Eph-B4-mediated AVF maturation. Approach and Results- In a mouse aortocaval fistula model, both Cav-1 mRNA and protein were increased in the AVF compared with control veins. Cav-1 KO (knockout) mice showed increased fistula wall thickening ( P=0.0005) and outward remodeling ( P<0.0001), with increased eNOS (endothelial NO synthase) activity compared with WT (wild type) mice. Ephrin-B2/Fc inhibited AVF outward remodeling in WT mice but not in Cav-1 KO mice and was maintained in Cav-1 RC (Cav-1 endothelial reconstituted) mice (WT, P=0.0001; Cav-1 KO, P=0.7552; Cav-1 RC, P=0.0002). Cavtratin-a Cav-1 scaffolding domain peptide-decreased AVF wall thickness in WT mice and in Eph-B4 het mice compared with vehicle alone (WT, P=0.0235; Eph-B4 het, P=0.0431); cavtratin also increased AVF patency (day 42) in WT mice ( P=0.0275). Conclusions- Endothelial Cav-1 mediates Eph-B4-mediated AVF maturation. The Eph-B4-Cav-1 axis regulates adaptive remodeling during venous adaptation to the fistula environment. Manipulation of Cav-1 function may be a translational strategy to enhance AVF patency.

CD44 Promotes Inflammation and Extracellular Matrix Production During Arteriovenous Fistula Maturation.

OBJECTIVE: Arteriovenous fistulae (AVF) remain the optimal conduit for hemodialysis access but continue to demonstrate poor patency and poor rates of maturation. We hypothesized that CD44, a widely expressed cellular adhesion molecule that serves as a major receptor for extracellular matrix components, promotes wall thickening and extracellular matrix deposition during AVF maturation. APPROACH AND RESULTS: AVF were created via needle puncture in wild-type C57BL/6J and CD44 knockout mice. CD44 mRNA and protein expression was increased in wild-type AVF. CD44 knockout mice showed no increase in AVF wall thickness (8.9 versus 26.8 µm; P=0.0114), collagen density, and hyaluronic acid density, but similar elastin density when compared with control AVF. CD44 knockout mice also showed no increase in vascular cell adhesion molecule-1 expression, intercellular adhesion molecule-1 expression, and monocyte chemoattractant protein-1 expression in the AVF compared with controls; there were also no increased M2 macrophage markers (transglutaminase-2: 81.5-fold, P=0.0015; interleukin-10: 7.6-fold, P=0.0450) in CD44 knockout mice. Delivery of monocyte chemoattractant protein-1 to CD44 knockout mice rescued the phenotype with thicker AVF walls (27.2 versus 14.7 µm; P=0.0306), increased collagen density (2.4-fold; P=0.0432), and increased number of M2 macrophages (2.1-fold; P=0.0335). CONCLUSIONS: CD44 promotes accumulation of M2 macrophages, extracellular matrix deposition, and wall thickening during AVF maturation. These data show the association of M2 macrophages with wall thickening during AVF maturation and suggest that enhancing CD44 activity may be a strategy to increase AVF maturation.

Ephrin type-B receptor 4 activation reduces neointimal hyperplasia in human saphenous vein in vitro.

BACKGROUND: Vein bypass is an essential therapy for patients with advanced peripheral and coronary artery disease despite development of neointimal hyperplasia. We have shown that stimulation of the receptor tyrosine kinase ephrin type-B receptor 4 (Eph-B4) with its ligand ephrin-B2 prevents neointimal hyperplasia in murine vein grafts. This study determines whether Eph-B4 in adult human veins is capable of phosphorylation and activation of downstream signaling pathways, as well as functional to release nitric oxide (NO) and prevent neointimal hyperplasia in vitro. METHODS: Discarded human saphenous veins were taken from the operating room and placed in organ culture without or with ephrin-B2/Fc (2 µg/mL) for 14 days, and the neointima/media ratio was measured in matched veins. Primary human umbilical vein endothelial cells were treated with ephrin-B2/Fc (2 µg/mL) and examined with quantitative polymerase chain reaction, Western blot, immunoassays, and for release of NO. Ephrin-B2/Fc (2 µg/mL) was placed on the adventitia of saphenous veins treated with arterial shear stress for 24 hours in a bioreactor and activated Eph-B4 examined with immunofluorescence. RESULTS: The baseline intima/media ratio in saphenous vein rings was 0.456 ± 0.097, which increased to 0.726 ± 0.142 in untreated veins after 14 days in organ culture but only to 0.630 ± 0.132 in veins treated with ephrin-B2/Fc (n = 19, P = .017). Ephrin-B2/Fc stimulated Akt, endothelial NO synthase and caveolin-1 phosphorylation, and NO release (P = .007) from human umbilical vein endothelial cells (n = 6). Ephrin-B2/Fc delivered to the adventitia stimulated endothelial Eph-B4 phosphorylation after 24 hours of arterial stress in a bioreactor (n = 3). CONCLUSIONS: Eph-B4 is present and functional in adult human saphenous veins, with intact downstream signaling pathways capable of NO release and prevention of neointimal hyperplasia in vitro. Adventitial delivery of ephrin-B2/Fc activates endothelial Eph-B4 in saphenous veins treated with arterial shear stress in vitro. These results suggest that stimulation of Eph-B4 function may be a candidate strategy for translation to human clinical trials designed to inhibit venous neointimal hyperplasia.

Pretreatment of pericardial patches with antibiotics does not alter patch healing in vivo.

BACKGROUND: Pretreatment with antibiotics is commonly performed before surgical implantation of prosthetic materials. We previously showed that pericardial patches are infiltrated by macrophages and arterial stem cells after implantation into an artery. We hypothesized that antibiotic pretreatment would diminish the number of cells infiltrating into the patch, potentially affecting early neointimal formation. METHODS: Bovine pericardial patches were pretreated with saline, bacitracin (500 U/mL), or cephalexin (10 mg/mL) for 30 minutes before implantation into the Wistar rat infrarenal aorta. Patches were retrieved on day 7 or day 30 and analyzed for histology and cell infiltration. Markers of proliferation, apoptosis, vascular cell identity, and M1 and M2 macrophage subtypes were examined using immunofluorescence and immunohistochemistry. Extracted proteins were analyzed by Western blot. RESULTS: At day 7, pericardial patches pretreated with bacitracin or cephalexin showed similar amounts of neointimal thickening (P = .55) and cellular infiltration (P = .42) compared with control patches. Patches pretreated with antibiotics showed similar proliferation (P = .09) and apoptosis (P = .84) as control patches. The cell composition of the neointima in pretreated patches was similar to control patches, with a thin endothelial layer overlying a thin layer of smooth muscle cells (P = .45), and containing similar numbers of CD34-positive (P = .26) and vascular endothelial growth factor receptor 2-positive (P = .31) cells. Interestingly, within the body of the patch, there were fewer macrophages (P = .0003) and a trend towards fewer endothelial progenitor cells (P = .051). No M1 macrophages were found in or around any of the patches. M2 macrophages were present around the patches, and there was no difference in numbers of M2 macrophages surrounding control patches and patches pretreated with antibiotics (P = .24). There was no difference in neointimal thickness at day 30 between control patches and patches pretreated with antibiotics (P = .52). CONCLUSIONS: Pretreatment of bovine pericardial patches with the antibiotics bacitracin or cephalexin has no detrimental effect on early patch healing, with similar neointimal thickness, cellular infiltration, and numbers of M2 macrophages compared with control patches. These results suggest that the host vessel response to patch angioplasty using pericardial patches is adaptive remodeling (eg, arterial healing).

Disturbed shear stress reduces Klf2 expression in arterial-venous fistulae in vivo.

Laminar shear stress (SS) induces an antiproliferative and anti-inflammatory endothelial phenotype and increases Klf2 expression. We altered the diameter of an arteriovenous fistula (AVF) in the mouse model to determine whether increased fistula diameter produces disturbed SS in vivo and if acutely increased disturbed SS results in decreased Klf2 expression. The mouse aortocaval fistula model was performed with 22, 25, or 28 gauge needles to puncture the aorta and the inferior vena cava. Duplex ultrasound was used to examine the AVF and its arterial inflow and venous outflow, and SS was calculated. Arterial samples were examined with western blot, immunohistochemistry, and immunofluorescence analysis for proteins and qPCR for RNA. Mice with larger diameter fistulae had diminished survival but increased AVF patency. Increased SS magnitudes and range of frequencies were directly proportional to the needle diameter in the arterial limb proximal to the fistula but not in the venous limb distal to the fistula, with 22-gauge needles producing the most disturbed SS in vivo. Klf2 mRNA and protein expression was diminished in the artery proximal to the fistula in proportion to increasing SS. Increased fistula diameter produces increased SS magnitude and frequency, consistent with disturbed SS in vivo. Disturbed SS is associated with decreased mRNA and protein expression of Klf2. Disturbed SS and reduced Klf2 expression near the fistula are potential therapeutic targets to improve AVF maturation.

Advanced age and disease predict lack of symptomatic improvement after endovascular iliac treatment in male veterans.

BACKGROUND: Endovascular angioplasty and stent placement is currently the most frequent treatment for iliac artery occlusive disease. However, despite a successful endovascular procedure, some patients do not experience symptomatic improvement and satisfaction with their care. This study seeks to identify patient-related factors associated with lack of symptomatic improvement after endovascular iliac artery treatment in male veterans. METHODS: Retrospective review of patients treated with endovascular methods for iliac artery occlusive disease between January 2008 and July 2012 at VA Connecticut Healthcare System. Symptomatic improvement on the first post-operative visit was evaluated, with bilateral treatments counted separately. RESULTS: Sixty-two patients had 91 iliac arteries treated with angioplasty and stent placement. Forty-seven (52 percent) legs had critical limb ischemia, and 77 (85 percent) had at least two-vessel distal runoff. Angiographic success was 100 percent. Patient-reported symptomatic improvement at the first post-operative visit was 55 percent (50/91). Lack of symptomatic improvement correlated with older age (OR 1.09 [1.03-1.17], p = 0.008), presence of critical limb ischemia (OR 3.03 [1.09-8.65], p = 0.034), and need for additional surgical intervention (OR 5.61 [1.65-17.36], p = 0.006). Survival, primary and secondary patency, and freedom from restenosis were comparable between patients who reported symptomatic improvement and those who did not. CONCLUSIONS: Despite angiographically successful revascularization, patients who are older or have critical limb ischemia who are treated with isolated endovascular iliac artery intervention are more likely to require additional interventions and less likely to experience symptomatic improvement. These patients may need more extensive infra-inguinal revascularization than isolated iliac angioplasty and stent placement, despite a preserved ankle-brachial index. Quality of life needs to be measured with formal instruments after iliac artery endovascular treatment, especially to determine long term outcomes.

Temporal regulation of venous extracellular matrix components during arteriovenous fistula maturation.

PURPOSE: The venous limb of arteriovenous fistulae (AVF) adapts to the arterial environment by dilation and wall thickening; however, the temporal regulation of the expression of extracellular matrix (ECM) components in the venous limb of the maturing AVF has not been well characterized. We used a murine model of AVF maturation that recapitulates human AVF maturation to determine the temporal pattern of expression of these ECM components. METHODS: Aortocaval fistulae were created in C57BL/6J mice and the venous limb was analyzed on postoperative days 1, 3, 7, 21, and 42. A gene microarray analysis was performed on day 7; results were confirmed by qPCR, histology, and immunohistochemistry. Proteases, protease inhibitors, collagens, glycoproteins, and other non-collagenous proteins were characterized. RESULTS: The maturing AVF has increased expression of many ECM components, including increased collagen and elastin. Matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase 1 (TIMP1) showed increased mRNA and protein expression during the first 7 days of maturation. Increased collagen and elastin expression was also significant at day 7. Expression of structural proteins was increased later during AVF maturation. Osteopontin (OPN) expression was increased at day 1 and sustained during AVF maturation. CONCLUSIONS: During AVF maturation, there is significantly increased expression of ECM components, each of which shows distinct temporal patterns during AVF maturation. Increased expression of regulatory proteins such as MMP and TIMP precedes increased expression of structural proteins such as collagen and elastin, potentially mediating a controlled pattern of ECM degradation and vessel remodeling without structural failure.

GM-CSF treated F4/80+ BMCs improve murine hind limb ischemia similar to M-CSF differentiated macrophages.

Novel cell therapy is required to treat critical limb ischemia (CLI) as many current approaches require repeated aspiration of bone marrow cells (BMCs). The use of cultured BMCs can reduce the total number of injections required and were shown to induce therapeutic angiogenesis in a murine model of hind limb ischemia. Blood flow recovery was significantly improved in mice treated with granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent BMCs that secreted inflammatory cytokines. Angiogenesis, lymphangiogenesis, and blood flow recovery ratio were significantly higher in the GM-CSF-cultured F4/80+ macrophage (GM-Mø)-treated group compared with controls. Furthermore, Foxp3+ cell numbers and tissue IL-10 concentrations were significantly increased compared with controls. There was no significant difference in blood flow recovery between GM-Mø and M-CSF-cultured F4/80+ macrophages (M-Mø). Thus, GM-Mø were associated with improved blood flow in hind limb ischemia similar to M-Mø. The selective methods of culturing and treating GM-Mø cells similar to M-Mø cells could be used clinically to help resolve the large number of cells required for BMC treatment of CLI. This study demonstrates a novel cell therapy for CLI that can be used in conjunction with conventional therapy including percutaneous intervention and surgical bypass.

Vascular endothelial growth factor-C derived from CD11b+ cells induces therapeutic improvements in a murine model of hind limb ischemia.

OBJECTIVE: The use of bone marrow cells (BMCs) in therapeutic angiogenesis has been studied extensively. However, the critical paracrine effects of this treatment are still unclear. Therefore, we studied autotransfusable cells that produce vascular endothelial growth factor (VEGF), especially VEGF-C. METHODS: Male C57BL/6 mice with hind limb ischemia were administered intramuscular injections of phosphate-buffered saline as controls, or unsorted BMCs, sorted CD11b(+), or CD11b(-) cells from BMCs, and recombinant VEGF-C. To evaluate the treatments, perfusion was measured by laser Doppler scanning performed on days 0, 1, 3, 7, 14, 21, and 28. A functional assay was performed in parallel, with mice traversing an enclosed walkway. Capillary density was determined by directly counting vessels stained positive with von Willebrand factor at individual time points. Lymphangiogenesis was assessed by LYVE-1 positive cells. RESULTS: Postischemic recovery of hind limb perfusion significantly improved in BMC, CD11b(+), and VEGF-C treatment groups compared with the control groups, as assessed by laser Doppler scanning. On early operative days 1 and 3, the blood flow recovery ratio was higher in the CD11b(+)-treated group compared with BMC and VEGF-C treatment groups. In the functional assay, the VEGF-C group dramatically recovered compared with the control group. The capillary/myofiber ratio in the thigh muscle and number of LYVE-1 positive cells was higher in the CD11b(+) and VEGF-C groups than in controls. Furthermore, expression of VEGF-A, VEGF-C, and VEGF receptor messenger ribonucleic acid and protein was observed in CD11b(+) cells. CONCLUSIONS: The VEGF-C derived from CD11b(+) cells play a critical role in angiogenesis and lymphangiogenesis in a murine model of hind limb ischemia. Consequently, treatment with self-CD11b(+) cells accelerated recovery from ischemia and may be a promising therapeutic strategy for peripheral arterial disease patients.

Segmental arterial mediolysis accompanied by renal infarction and pancreatic enlargement: a case report.

INTRODUCTION: Due to recent advances in imaging diagnostic techniques, there are an increasing number of case reports of segmental arterial mediolysis. However, there are only a limited number of reports on segmental arterial mediolysis-related abnormalities of abdominal organs other than the intestine. This report describes a case of segmental arterial mediolysis accompanied by abnormalities of abdominal organs without clinical symptoms. CASE PRESENTATION: A 52-year-old Japanese man with hematuria and no prior medical history was referred to a urologist and was diagnosed as having urinary bladder cancer. He underwent trans-urethral resection of the bladder tumor and intra-vesical instillation therapy, which was followed by observation. During follow-up, although no abdominal symptoms were observed, an abdominal computed tomography scan revealed a dissection of the superior mesenteric artery. A false lumen partially occluded by a thrombus was located distal to this occlusion. The lumen was irregularly shaped with narrow and wide sections. Similar irregularities were also observed in the wall of the inferior mesenteric artery. Arterial dissection with thromboembolism in the left renal artery and renal infarction was also observed. Follow-up computed tomography after two months revealed an enlargement of the pancreatic tail adjacent to the splenic artery. Follow-up three-dimensional computed tomography showed gradual re-expansion of the true lumen of the superior mesenteric artery, improvement in arterial wall irregularities, and a reduction in the pancreas enlargement and renal infarction. Over the following 15 months, these changes gradually normalized. On the basis of the vascular changes in multiple arterial systems that resolved spontaneously, we considered that the lesions were associated with segmental arterial mediolysis. CONCLUSIONS: We present a rare case of segmental arterial mediolysis accompanied by abnormalities of abdominal organs without clinical symptoms. Three-dimensional computed tomography was useful for follow-up evaluation in our patient.

Safety and efficacy of an ultrashort-acting ß1-blocker on left ventricular dysfunction.

Landiolol hydrochloride, an ultrashort-acting ß1-selective blocker, is a highly regulated drug. This study evaluated the safety and efficacy of this drug for cases of coronary artery bypass grafting (CABG) with left ventricular dysfunction. Between September 2006 and August 2009, 32 patients with a left ventricular ejection fraction of <40% underwent CABG. Two groups of patients, a group administered landiolol hydrochloride and a control group not administered this drug, were compared. The administration of landiolol hydrochloride was initiated at 1 µg/kg per minute (γ) after cardiopulmonary bypass in on-pump cases and after completion of all the distal anastomoses in off-pump cases. We observed no significant differences between the groups with respect to preoperative patient background or incidences of complications, except for postoperative atrial fibrillation. The heart rate decreased significantly 30 minutes after landiolol hydrochloride administration, but no change was observed in arterial pressure. No change was observed in other parameters; the hemodynamics were stable. The occurrence of atrial fibrillation during the intensive care unit stay (during landiolol hydrochloride administration) was significantly lower in the administration group. The difference remained significant after multiple logistic regression analysis; landiolol hydrochloride was the sole inhibitory factor.

WITHDRAWN: Endoscopic Radial Artery Harvesting: Long-Term Results and Graft Patency Rate.

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy. This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.

Two-layer tissue engineered urethra using oral epithelial and muscle derived cells.

PURPOSE: We fabricated novel tissue engineered urethral grafts using autologously harvested oral cells. We report their viability in a canine model. MATERIALS AND METHODS: Oral tissues were harvested by punch biopsy and divided into mucosal and muscle sections. Epithelial cells from mucosal sections were cultured as epithelial cell sheets. Simultaneously muscle derived cells were seeded on collagen mesh matrices to form muscle cell sheets. At 2 weeks the sheets were joined and tubularized to form 2-layer tissue engineered urethras, which were autologously grafted to surgically induced urethral defects in 10 dogs in the experimental group. Tissue engineered grafts were not applied to the induced urethral defect in control dogs. The dogs were followed 12 weeks postoperatively. Urethrogram and histological examination were done to evaluate the grafting outcome. RESULTS: We successfully fabricated 2-layer tissue engineered urethras in vitro and transplanted them in dogs in the experimental group. The 12-week complication-free rate was significantly higher in the experimental group than in controls. Urethrogram confirmed urethral patency without stricture in the complication-free group at 12 weeks. Histologically urethras in the transplant group showed a stratified epithelial layer overlying well differentiated submucosa. In contrast, urethras in controls showed severe fibrosis without epithelial layer formation. CONCLUSIONS: Two-layer tissue engineered urethras were engineered using cells harvested by minimally invasive oral punch biopsy. Results suggest that this technique can encourage regeneration of a functional urethra.

Oriented Collagen Scaffolds for Tissue Engineering.

Oriented collagen scaffolds were developed in the form of sheet, mesh and tube by arraying flow-oriented collagen string gels and dehydrating the arrayed gels. The developed collagen scaffolds can be any practical size with any direction of orientation for tissue engineering applications. The birefringence of the collagen scaffolds was quantitatively analyzed by parallel Nicols method. Since native collagen in the human body has orientations such as bone, cartilage, tendon and cornea, and the orientation has a special role for the function of human organs, the developed various types of three-dimensional oriented collagen scaffolds are expected to be useful biomaterials for tissue engineering and regenerative medicines.

Efficacy of propafenone hydrochloride in preventing postoperative atrial fibrillation after coronary artery bypass grafting.

BACKGROUND: Atrial fibrillation (AF) is one of the most common complications after coronary artery bypass grafting (CABG), and the incidence of postoperative AF (PAF) is estimated to range from 10% to 40%. PAF is a serious complication that is related to unstable hemodynamics, development of embolisms, patient discomfort, and increased medical costs associated with the prolongation of hospital stay. Sometimes, immediate attention is also necessary. In this study, we assessed the efficacy of treatment with the antiarrhythmic drug propafenone hydrochloride, which was administered in the early postoperative period, in preventing the development of PAF, and we attempted to identify risk factors for PAF. MATERIALS AND METHODS: The subjects were 78 patients who underwent isolated off-pump CABG between July 2007 and October 2008. We conducted the study by dividing the patients into 2 groups, a group of 26 patients who received propafenone hydrochloride (P group) and a control group of 52 patients who did not receive this drug (C group). The patients in the P group were given propafenone hydrochloride (150-450 mg/day orally) for 10 days, starting on the day after surgery, and were observed for the development of AF by means of continuous 12-lead electrocardiographic monitoring. Development of AF was defined as AF that lasted