Diverse Shape Design and Physical Property Evaluation of In-Body Tissue Architecture-Induced Tissues.

Autologous-engineered artificial tissues constitute an ideal alternative for radical surgery in terms of natural anticoagulation, self-repair, tissue regeneration, and the possibility of growth. Previously, we focused on the development and practical application of artificial tissues using "in-body tissue architecture (iBTA)", a technique that uses living bodies as bioreactors. This study aimed to further develop iBTA by fabricating tissues with diverse shapes and evaluating their physical properties. Although the breaking strength increased with tissue thickness, the nominal breaking stress increased with thinner tissues. By carving narrow grooves on the outer periphery of an inner core with narrow grooves, we fabricated approximately 2.2 m long cord-shaped tissues and net-shaped tissues with various designs. By assembling the two inner cores inside the branched stainless-steel pipes, a large graft with branching was successfully fabricated, and its aortic arch replacement was conducted in a donor goat without causing damage. In conclusion, by applying iBTA technology, we have made it possible, for the first time, to create tissues of various shapes and designs that are difficult using existing tissue-engineering techniques. Thicker iBTA-induced tissues exhibited higher rupture strength; however, rupture stress was inversely proportional to thickness. These findings broaden the range of iBTA-induced tissue applications.

Breaking the Limit of Cardiovascular Regenerative Medicine: Successful 6-Month Goat Implant in World's First Ascending Aortic Replacement Using Biotube Blood Vessels.

This study investigated six-month outcomes of first models of ascending aortic replacement. The molds used to produce the Biotube were implanted subcutaneously in goats. After 2-3 months, the molds were explanted to obtain the Biotubes (inner diameter, 12 mm; wall thickness, 1.5 mm). Next, we performed ascending aortic replacement using the Biotube in five allogenic goats. At 6 months, the animals underwent computed tomography (CT) and histologic evaluation. As a comparison, we performed similar surgeries using glutaraldehyde-fixed autologous pericardial rolls or pig-derived heterogenous Biotubes. At 6 months, CT revealed no aneurysmalization of the Biotube or pseudoaneurysm formation. The histologic evaluation showed development of endothelial cells, smooth muscle cells, and elastic fibers along the Biotube. In the autologous pericardium group, there was no evidence of new cell development, but there was calcification. The histologic changes observed in the heterologous Biotube group were similar to those in the allogenic Biotube group. However, there was inflammatory cell infiltration in some heterologous Biotubes. Based on the above, we could successfully create the world's first Biotube-based ascending aortic replacement models. The present results indicate that the Biotube may serve as a scaffold for aortic tissue regeneration.

Reversible complete atrioventricular block caused by aortic bicuspid valve calcification with severe aortic stenosis: a case report.

Background: The aetiology of secondary complete atrioventricular blocks includes ischaemia, cardiac sarcoidosis, electrolyte imbalance, drug use, rheumatic fever, and infections such as Lyme disease and endocarditis. Diagnosis is important since some of these causes are reversible. Although several studies have reported on aortic valve calcification causing complete atrioventricular blocks, no study has described improvement of complete atrioventricular blocks by removal of the calcification. Case summary: A 42-year-old man with syncope had a Mobitz type II atrioventricular block, an alternating bundle branch block, and severe aortic stenosis. We identified a 10 s paroxysmal complete atrioventricular block with pre-syncope and performed pacemaker implantation. Electrocardiography-gated computed tomography confirmed that the calcification had reached the muscular septum. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) revealed significant FDG uptake with high CT value of calcification in basal interventricular septum. The calcification in the septum was removed carefully, and aortic valve replacement was performed. The atrioventricular conduction capacity improved post-surgery. During the 1-year follow-up, the patient reported dramatic improvement in exercise capacity. We also noted an improvement of <0.1% in the right ventricular pacing burden. Discussion: Complete atrioventricular blocks occur in patients with aortic stenosis accompanied by severe calcification of the aortic valve, which are visualized comprehensively by echocardiography. Electrocardiography-gated computed tomography and FDG-PET enabled detailed evaluation of the extent of calcification and pre- and post-operative tissue inflammation. Hence, we suspected that the calcification in the septum was causing complete atrioventricular block. Moreover, clinicians should recognize that aortic valve calcification with aortic stenosis can cause complete atrioventricular blocks.

Quality of epicardial adipose tissue predicts major adverse cerebral and cardiovascular events following transcatheter aortic valve implantation.

Epicardial adipose tissue (EAT) have been shown to be associated with several heart disease, including coronary artery disease (CAD), atrial fibrillation (AF), and heart failure (HF). It is reported that the quality of EAT, represented by fat attenuation determined using computed tomography (CT) imaging, can detect the histologically-assessed remodeled EAT. We tested the hypothesis that quality of EAT would predict major adverse cerebral and cardiovascular events (MACCE) following transcatheter aortic valve implantation (TAVI) in patients with aortic stenosis (AS). A total of 125 consecutive severe AS patients who underwent TAVI were enrolled (39 male, mean 85.4 ± 4.0 years). Using CT imaging before TAVI, we measured the average CT fat attenuation of EAT (EAT attenuation) and investigated the association with MACCE. During the mean follow up period of 567 ± 371 days, 21 cases of MACCE were observed. Patients with MACCE had greater levels of EAT attenuation compared to those without (- 74 ± 3.7 Hounsfield Units (HU) vs - 77 ± 5.5 HU, p = 0.010). Based on the ROC curves, the high EAT attenuation was defined as > - 74.3 HU. According to this cut-off index, 44 patients were classified into the high EAT attenuation group (28 female, mean age 87 ± 3.6 years), whereas 81 patients were classified into the low EAT attenuation group (13 female, 85 ± 4.1 years). Kaplan-Meier survival curve demonstrated that the patients in the high EAT attenuation group showed greater prevalence of MACCE (log-rank 6.64, p = 0.010). Cox proportional hazards regression analysis revealed that EAT attenuation and Logistic EuroSCORE were independently associated with the incidence of MACCE. Our results suggest that quality of EAT, assessed by EAT attenuation detected by CT imaging, can predict the cerebral and cardiovascular events after TAVI in patients with AS.

Detection and identification of factors in the atrium responsible for blood pressure regulation in patients with hypertension.

Resection of the left atrial appendage reportedly improves blood pressure in patients with hypertension. This study aimed to validate the transcriptional profiles of atrial genes responsible for blood pressure regulation in patients with hypertension as well as to identify the molecular mechanisms in rat biological systems. RNA sequencing data of left atrial appendages from patients with (n = 6) and without (n = 6) hypertension were subjected to unsupervised principal component analysis (PCA). Reduction of blood pressure was reflected by third and ninth principal components PC3 and PC9, and that eighteen transcripts, including endothelin-1, were revealed by PCA-based pathway analysis. Resection of the left atrial appendage in hypertensive rats improved their blood pressure accompanied by a decrease in serum endothelin-1 concentration. Expression of the endothelin-1 gene in the atrium and atrial appendectomy could play roles in blood pressure regulation in humans and rats.

Carotid Artery Bypass Surgery of In-Body Tissue Architecture-Induced Small-Diameter Biotube in a Goat Model: A Pilot Study.

Biotubes are autologous tubular tissues developed within a patient's body through in-body tissue architecture, and they demonstrate high potential for early clinical application as a vascular replacement. In this pilot study, we used large animals to perform implantation experiments in preparation for preclinical testing of Biotube. The biological response after Biotube implantation was histologically evaluated. The designed Biotubes (length: 50 cm, internal diameter: 4 mm, and wall thickness: 0.85 mm) were obtained by embedding molds on the backs of six goats for a predetermined period (1-5 months). The same goats underwent bypass surgery on the carotid arteries using Biotubes (average length: 12 cm). After implantation, echocardiography was used to periodically monitor patency and blood flow velocity. The maximum observation period was 6 months, and tissue analysis was conducted after graft removal, including the anastomosis. All molds generated Biotubes that exceeded the tensile strength of normal goat carotid arteries, and eight randomly selected Biotubes were implanted. Thrombotic occlusion occurred immediately postoperatively (1 tube) if anticoagulation was insufficient, and two tubes, with insufficient Biotube strength (<5 N), were ruptured within a week. Five tubes maintained patency for >2 months without aneurysm formation. The spots far from the anastomosis became stenosed within 3 months (3 tubes) when Biotubes had a wide intensity distribution, but the shape of the remaining two tubes remained unchanged for 6 months. The entire length of the bypass region was walled with an αSMA-positive cell layer, and an endothelial cell layer covered most of the lumen at 2 months. Complete endothelial laying of the luminal surface was obtained at 3 months after implantation, and a vascular wall structure similar to that of native blood vessels was formed, which was maintained even at 6 months. The stenosis was indicated to be caused by fibrin adhesion on the luminal surface, migration of repair macrophages, and granulation formation due to the overproliferation of αSMA-positive fibroblasts. We revealed the importance of Biotubes that are homogeneous, demonstrate a tensile strength > 5 N, and are implanted under appropriate antithrombotic conditions to achieve long-term patency of Biotube. Further, we clarified the Biotube regeneration process and the mechanism of stenosis. Finally, we obtained the necessary conditions for a confirmatory implant study planned shortly.

Urgent endovascular mycotic aortic arch aneurysm repair using in situ laser fenestration and selective arterial perfusion with venoarterial extracorporeal membrane oxygenation.

In recent years, mycotic aortic aneurysms have been increasingly treated successfully by endovascular means. The introduction of custom-made fenestrated and branched devices, parallel graft techniques, and in situ fenestration has enabled total endovascular treatment also for arch pathologies. We describe a total endovascular repair of a mycotic arch aneurysm with in situ laser fenestration using venoarterial extracorporeal membrane oxygenation to preserve flow to vital organs.

Low-flow perfusion technique for shaggy aortic arch.

BACKGROUND: The most common complication of thoracic aortic disease with shaggy aorta is cerebral infarction. We have performed "low-flow perfusion" as a method of extracorporeal circulation to prevent cerebral embolism in patients with strong atherosclerotic lesions in the aortic arch. METHODS: "Low-flow perfusion" is a method in which cardiopulmonary bypass is started by partial blood removal, approaching deep hypothermia while maintaining self-cardiac output. We compared the outcomes of 12 patients who underwent the "low-flow perfusion" method (Group L) with those of 12 who underwent normal extracorporeal circulation (Group N) during aortic arch surgery since 2019. RESULTS: Group L consisted of 8 males with an average age of 73 years old, and Group N consisted of 6 males with an average age of 73 years old. The average time from the start of cooling to ventricular fibrillation was 9.5 min in Group L and 3.6 min in Group N (p < 0.01). The eardrum temperature when ventricular fibrillation was reached was 28.2 °C in Group L and 32.5 °C in Group N (p = 0.01). A blood flow analysis also revealed low wall shear stress on the lesser curvature of the aortic arch. CONCLUSION: With this method, the intracranial temperature was sufficiently low at the time of ventricular fibrillation, and there was no need to increase the total pump flow. The low-flow perfusion method can prevent cerebral embolism by preventing atheroma destruction by the blood flow jet while maintaining the self-cardiac output during the cooling process.

Empagliflozin Suppresses the Differentiation/Maturation of Human Epicardial Preadipocytes and Improves Paracrine Secretome Profile.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce epicardial adipose tissue (EAT) in humans, enhancing cardioprotective effects on heart failure and atrial fibrillation. We investigated the direct effect of the SGLT2 inhibitor empagliflozin on human primary epicardial adipocytes and preadipocytes. SGLT2 is primarily expressed in human preadipocytes in the EAT. The expression levels of SGLT2 significantly diminished when the preadipocytes were terminally differentiated. Adipogenesis of preadipocytes was attenuated by empagliflozin treatment without affecting cell proliferation. The messenger RNA levels and secreted protein levels of interleukin 6 and monocyte chemoattractant protein 1 were significantly decreased in empagliflozin-treated adipocytes. Coculture of human induced pluripotent stem cell-derived atrial cardiomyocytes and adipocytes pretreated with or without empagliflozin revealed that empagliflozin significantly suppressed reactive oxygen species. IL6 messenger RNA expression in human EAT showed significant clinically relevant associations. Empagliflozin suppresses human epicardial preadipocyte differentiation/maturation, likely inhibiting epicardial adipogenesis and improving the paracrine secretome profile of EAT, particularly by regulating IL6 expression.

Totally endoscopic pulmonary valve replacement.

A 68-year-old man with a history of valve-sparing aortic root replacement and endoscopic aortic valve replacement was admitted to our hospital with dyspnea. Transthoracic echocardiography revealed severe pulmonary valve regurgitation. The patient had undergone cardiac surgery twice, through median sternotomy and right thoracotomy; therefore, we planned endoscopic pulmonary valve replacement via the left thoracic approach. The patient was placed in a modified right lateral decubitus position and underwent mild hypothermic cardiopulmonary bypass. An on-pump beating-heart technique was used during surgery. The 3D endoscopic system and trocars for surgical instruments were inserted through the left 3rd and 4th intercostal spaces. After incision of the pulmonary artery, the pulmonary cusps were resected. A 27-mm St Jude Medical Epic heart valve was implanted in the intra-annular position. Subsequently, the left atrial appendage was resected. The patient was discharged without complications. To our knowledge, this is the first case of totally endoscopic pulmonary valve replacement.

[Traumatic Right Atrial Rupture and Right Ventricular Papillary Muscle Rupture].

A 18-year-old man was driving at 100 km/h on a motorbike and collided with a utility pole. He was taken to our hospital in a state of shock due to an unstable pelvic fracture and cardiac tamponade. Pericardial drainage was carried out, but intrapericardial hemorrhage persisted and the patient underwent emergency thoracotomy and suture of right atrial injury. After hemodynamic condition improved, the patient was transferred to a tertiary care facility. For the pelvic fracture, open reduction and fixation was performed on the 6th day after injury. During recovery, moderate mitral valve regurgitation and severe tricuspid valve regurgitation due to rupture of the right ventricular papillary muscle were diagnosed. The patient's exercise tolerance was too reduced to continue rehabilitation. Thirty-seven days after the injury, mitral and tricuspid valve repair was performed. Four months after the injury, he was discharged without sequelae.

Bioprosthetic Valve Deterioration: Accumulation of Circulating Proteins and Macrophages in the Valve Interstitium.

Histologic evaluations revealed excessive accumulations of macrophages and absence of fibroblastic interstitial cells in explanted bioprosthetic valves. Comprehensive gene and protein expression analysis and histology unveiled an accumulation of fibrinogen and plasminogen, an activator of infiltrated macrophages, from degenerated valve surfaces in the interstitial spaces. These pathologies were completely reproduced in a goat model replaced with an autologous pericardium-derived aortic valve. Further preclinical animal experiments using goats demonstrated that preventing infiltration of macrophages and circulating proteins by increasing collagen density and leaflet strength is an effective treatment option.

A case of sigmoid colon perforation due to segmental absence of intestinal musculature (SAIM) accompanied by vascular Ehlers-Danlos syndrome: a case report.

BACKGROUND: Segmental absence of intestinal musculature (SAIM) is a partial defect of the intrinsic muscular layer of the intestinal tract. In this report, we describe a case of perforation of the sigmoid colon due to SAIM accompanied by vascular Ehlers-Danlos syndrome (vEDS), which was successfully treated by surgical therapy. CASE PRESENTATION: A male in his 30 s was being followed up for vEDS diagnosed by genetic testing. He had undergone two major vascular surgeries, abdominal aortic artery revascularization and thoracic endovascular aortic repair for a residual dissection and enlarging abdominal aortic aneurysm. On postoperative day 11, the patient developed perforation of the sigmoid colon for which intraperitoneal lavage and drainage, Hartmann surgery, and transverse colostomy were performed. Histological findings showed no disturbance of blood flow or diverticulum but did show a defect in the intrinsic muscular layer around the perforation site, leading to the pathological diagnosis of SAIM and associated perforation of the sigmoid colon. Postoperatively, the patient had no complications and was discharged on postoperative day 18. The patient is being followed as an outpatient and has experienced no relapse. CONCLUSIONS: Both SAIM and vEDS, which may be related diseases, are associated with the presence of tissue fragility and have a high potential to cause intestinal perforation Caution should be exercised during surveillance in patients with constipation and examinations that cause increased intestinal pressure.

Leiomyosarcoma Presenting as Rupture With a Type II Endoleak After Thoracic Endovascular Aortic Repair.

Endovascular stent-graft therapy is a commonly performed procedure for aortic lesions worldwide and complications unique to stent grafts, such as postoperative endoleaks, are well known. However, as this treatment modality becomes more popular, physicians should carefully monitor for other unexpected complications, which may not always be related to the graft. This study presents a case of leiomyosarcoma of the aorta that developed during follow-up for a type II endoleak (T2EL) after thoracic endovascular aortic repair. The presence of the T2EL hindered the diagnosis of the sarcoma at an early stage. These findings suggest that an apparent aneurysm that grows suddenly during follow-up after stent grafting should raise the index of suspicion for a neoplasm as well as an endoleak.

[Totally Endoscopic Surgery for the Left Atrial Myxoma and the Atrial Septal Defect:Report of a Case].

A 60-year-old woman was admitted to our institution for exertional dyspnea. Transthoracic echocardiography revealed a 1.6 cm secundum atrial septal defect( ASD) and a 4.2×3.1 cm mobile left atrial mass originating from the ASD. The tumor migrated to the mitral valve during diastole and to the atrial septal defect during systole. A totally endoscopic approach via a small right thoracotomy was adopted to resect the mass and close the ASD with a Hemashield patch. Histopathologic examination of the excised mass was consistent with myxoma. The postoperative course was uneventful. A 2-year follow-up revealed no recurrence of the myxoma and ASD.

Endoscopic-assisted descending aortic replacement through a small intercostal incision: a case report.

BACKGROUND: Descending aortic replacement often involves making large incisions; thus, it results in massive invasions. We report the case of a patient with dilated descending aorta treated using endoscopic-assisted descending aortic replacement with essentially minimal invasions. CASE PRESENTATION: We performed endoscopic-assisted descending aortic replacement with a single incision involving six wounds by trocar puncturing on a 59-year-old man who was diagnosed with dilated descending aorta by stent graft-induced new entry. Subsequently, the patient was discharged on postoperative day 11 without any complications. CONCLUSIONS: Despite minor incisions, our approach can be indicated to almost the same group of patients in whom the conventional approach can be performed. Our procedure involved a single incision of only 8 cm and six wounds by trocar puncturing. Thus, endoscopic-assisted surgery can be a useful option in descending aortic surgery.

Pre-implantation evaluation of a small-diameter, long vascular graft (Biotube®) for below-knee bypass surgery in goats.

There are no small-diameter, long artificial vascular grafts for below-knee bypass surgery in chronic limb-threatening ischemia. We have developed tissue-engineered vascular grafts called "Biotubes®" using a completely autologous approach called in-body tissue architecture (iBTA). This study aimed at pre-implantation evaluation of Biotube and its in vivo preparation device, Biotube Maker, for use in below-knee bypass surgery. Forty nine makers were subcutaneously embedded into 17 goats for predetermined periods (1, 2, or 3 months). All makers produced Biotubes as designed without inflammation over all periods, with the exception of a few cases with minor defects (success rate: 94%). Small hole formation occurred in only a few cases. All Biotubes obtained had an inner diameter of 4 mm and a length of 51 to 52 cm with a wall thickness of 594 ± 97 µm. All Biotubes did not kink when completely bent under an internal pressure of 100 mmHg and did not leak without any deformation under a water pressure of 200 mmHg. Their burst strength was 2409 ± 473 mmHg, and suture retention strength was 1.75 ± 0.27 N, regardless of the embedding period, whereas tensile strength increased from 7.5 ± 1.3 N at 1 month to 9.7 ± 2.0 N at 3 months with the embedding period. The amount of water leakage from the needle holes prepared in the Biotube wall was approximately 1/7th of that in expanded polytetrafluoroethylene vascular grafts. The Biotubes could be easily connected to each other without cutting or anastomosis leaks. They could be stored for at least 1 year at room temperature. This study confirmed that even Biotubes formed 1 month after embedding of Biotube Makers had properties comparable to arteries.

Potential efficacy of multipoint pacing in the reduction of mitral regurgitation volume: a case report.

A 70-year-old woman who had cardiac sarcoidosis and severe tethering mitral regurgitation (MR) and had been implanted with a biventricular pacemaker experienced recurrent hospitalisation due to decompensated heart failure (HF). Application of MultiPoint™ pacing reduced the MR volume and maintained the symptoms under control; however, the predicted longevity of the device significantly decreased because of the very high threshold of the added pacing site. Transcatheter mitral valve repair (TMVR) using MitraClip® was performed to further diminish the severe MR, thereby enabling the switch from highly consumptive multipoint pacing (MPP) to energy-saving single-point pacing. MPP could further reduce MR compared to the conventional single-point pacing, and this could be a bridging therapy to TMVR in some patients implanted with a biventricular pacemaker. This is the first case to report that switching from conventional single-point pacing to MPP decreased the MR, to some extent, resulting in the improvement of HF symptoms.

One-year results with a low-profile endograft in subjects with thoracic aortic aneurysm and ulcer pathologies.

OBJECTIVE: The study objective was to evaluate the safety and effectiveness of the second-generation, low-profile RelayPro (Terumo Aortic) thoracic endograft for the treatment of descending thoracic aortic aneurysm or penetrating atherosclerotic ulcer. METHOD: A prospective, international, nonblinded, nonrandomized, pivotal trial analyzed a primary safety end point of major adverse events at 30 days (death, myocardial infarction, stroke, renal/respiratory failure, paralysis, bowel ischemia, procedural blood loss) and a primary effectiveness end point of treatment success at 1 year (technical success, patency, absence of aneurysm rupture, type I/III endoleaks, stent fractures, reinterventions, aneurysm expansion, and migration) compared with performance goals from the previous generation Relay pivotal study. The study was conducted in 36 centers in the United States and Japan and enrolled participants between 2017 and 2019. RESULTS: The study population of 110 patients had a median (interquartile range) age of 76 (70-81) years, 69 (62.7%) were male, and 43 (39.1%) were Asian. Patients were treated for 76 fusiform aneurysms (69%), 24 saccular aneurysms (22%), and 10 penetrating atherosclerotic ulcers (9%). Most patients (82.7%) were treated with a non-bare stent configuration. Technical success was 100%. The median (interquartile range) procedure time was 91 (64-131) minutes, and the deployment time was 16 (10-25) minutes. A total of 50 patients (73.5%) in the US cohort had percutaneous access, whereas centers in Japan used only surgical cutdown. The 30-day composite major adverse events rate was 6.4% (95% upper confidence interval, 11.6%; P = .0002): 2 strokes, 2 procedural blood losses greater than 1000 mL requiring transfusion, 2 paralysis events, and 1 renal failure. Primary effectiveness was 89.2% (lower 95% confidence interval, 81.8%; P = .0185). Nine subjects experienced 11 events (1 aneurysm expansion, 6 secondary interventions, and 4 type I endoleaks). There was no loss of stent-graft patency, no rupture, no fractures, and no migration. CONCLUSIONS: The low-profile RelayPro thoracic endograft met the study primary end points and demonstrated satisfactory 30-day safety and 1-year effectiveness for the treatment of patients with aneurysms of the descending thoracic aorta or penetrating atherosclerotic ulcers. Follow-up is ongoing to evaluate longer-term outcomes and durability.