Utilizing a long sheath to minimize atheroma manipulation (minimal manipulation approach) during Zone 1 and 2 thoracic endovascular aortic repair with a shaggy aorta.

We have adopted a simple and reproducible approach, "minimal manipulation approach," since January 2021 in five patients to minimize the risk of thromboembolic events during Zone 1 and 2 thoracic endovascular aortic repair (TEVARs) with shaggy aorta. The approach consists of two parts: ① Use of a 65-cm-long sheath (dry seal) to deliver the endografts without touching the protruding atheroma. Covering the atheroma with the first endograft delivered at Zone 3 to the mid-descending aorta (paving the aorta), and second endograft insertion and deployment through the paved aorta with first endograft. ② Protection of the left subclavian artery using balloon catheter during TEVAR. No in-hospital mortality was recorded, and none of the patients had stroke, spinal cord ischemia, or distal embolic events.

Side-by-side deployment of gore excluder legs at a narrow terminal aorta for endovascular aneurysm repair.

PURPOSE: A narrow terminal aorta is a risk factor for endograft occlusion after endovascular aneurysm repair. To minimize limb complications, we used Gore Excluder legs positioned side-by-side at the terminal aorta. We investigated the outcomes of our strategy for endovascular aneurysm repair in patients with a narrow terminal aorta. METHODS: We enrolled 61 patients who underwent endovascular aneurysm repair with a narrow terminal aorta (defined as < 18 mm in diameter) from April 2013 to October 2021. The standard procedure involves complete treatment with the Gore Excluder device. When other types of main body endografts were used, they were deployed proximal to the terminal aorta, and we used the Gore Excluder leg device in the bilateral limbs. Postoperatively, the intraluminal diameter of the legs at the terminal aorta was measured to assess the configuration. RESULTS: During the follow-up period (mean: 2.7 ± 2.0 years), there were no aorta-related deaths, endograft occlusions, or leg-related re-interventions. There were no significant differences between the pre- and postoperative ankle-brachial pressure index values in the dominant and non-dominant legs (p = 0.44 and p = 0.17, respectively). Postoperatively, the mean difference rate (defined as [dominant leg diameter-non-dominant leg diameter]/terminal aorta diameter) was 7.5 ± 7.1%. The difference rate was not significantly correlated with the terminal aortic diameter, calcification thickness, or circumferential calcification (r = 0.16, p = 0.22; r = 0.07, p = 0.59; and r = - 0.07, p = 0.61, respectively). CONCLUSIONS: Side-by-side deployment of Gore Excluder legs produces acceptable outcomes for endovascular aneurysm repair with a narrow terminal aorta. The endograft expansion at the terminal aorta is tolerable without influencing calcification distribution.

Pulmonary artery augmentation and aortic valve repair using novel tissue-engineered grafts.

Objectives: The objectives of this study were to evaluate the results when tissue-engineered vascular grafts (TEVGs) are used as alternatives to autologous pericardium for surgically augmenting the pulmonary artery (PA) or aortic valve. Methods: TEVG molds were embedded into subcutaneous spaces for more than 4 weeks preoperatively. Since 2014, 6 patients have undergone PA reconstruction, whereas 1 has undergone aortic valve plasty (AVP) with TEVGs. The time from mold implantation to the operation was 8.9 (range, 6.0-26.4) months. The age and body weight at the time of operation were 2.7 (range, 1.8-9.2) and 11.6 (range, 7.9-24.4) kg, respectively. Concomitant procedures comprised the Rastelli, palliative Rastelli, and Fontan operations in 2, 2, and 1 patient, respectively. Results: The median follow-up period was 14.4 (range, 3-39.6) months. There were no early or late mortalities. Moreover, there were no TEVG-related complications, including aneurysmal changes, degeneration, and infection. In 5 patients who underwent PA augmentation, the postoperative PA configuration was satisfactorily dilated. The reconstructed aortic valve function was good in the patient who underwent AVP. Decreased leaflet flexibility due to leaflet thickening was not observed. One patient had postoperative PA re-stenosis; therefore, re-PA augmentation with TEVGs was performed. On histological examination, TEVGs consisted of collagen fibers and few fibroblasts, and elastic fiber formation and/or smooth muscle cells were not observed. Conclusions: The midterm results of PA reconstruction and AVP with TEVGs were satisfactory. TEVGs might be a useful alternative to autologous pericardium in pediatric cardiovascular surgeries that often require multistage operations.

A tissue-engineered, decellularized, connective tissue membrane for allogeneic arterial patch implantation.

BACKGROUND: We have previously applied in vivo tissue-engineered vascular grafts constructed in patients' subcutaneous spaces. However, since the formation of these vascular grafts depends on host health, their application is challenging in patients with suppressed regenerative ability. Therefore, the allogeneic implantation of grafts from healthy donors needs to be evaluated. This study aimed to fabricate allogeneic cardiovascular grafts in animals. MATERIALS AND METHODS: Silicone rod molds were implanted into subcutaneous pouches in dogs; the implants, along with surrounding connective tissues, were harvested after four weeks. Tubular connective tissues were decellularized and stored before they were cut open, trimmed to elliptical sheets, and implanted into the common carotid arteries of another dog as vascular patches (n = 6); these were resected and histologically evaluated at 1, 2, and 4 weeks after implantation. RESULTS: No aneurysmal changes were observed by echocardiography. Histologically, we observed neointima formation on the luminal graft surface and graft wall cell infiltration. At 2 and 4 weeks after implantation, α-SMA-positive cells were observed in the neointima and graft wall. At 4 weeks after implantation, the endothelial lining was observed at the grafts' luminal surfaces. CONCLUSION: Our data suggest that decellularized connective tissue membranes can be prepared and stored for later use as allogeneic cardiovascular grafts.

Modifications of the mechanical properties of in vivo tissue-engineered vascular grafts by chemical treatments for a short duration.

In vivo tissue-engineered vascular grafts constructed in the subcutaneous spaces of graft recipients have functioned well clinically. Because the formation of vascular graft tissues depends on several recipient conditions, chemical pretreatments, such as dehydration by ethanol (ET) or crosslinking by glutaraldehyde (GA), have been attempted to improve the initial mechanical durability of the tissues. Here, we compared the effects of short-duration (10 min) chemical treatments on the mechanical properties of tissues. Tubular tissues (internal diameter, 5 mm) constructed in the subcutaneous tissues of beagle dogs (4 weeks, n = 3), were classified into three groups: raw tissue without any treatment (RAW), tissue dehydrated with 70% ET (ET), and tissue crosslinked with 0.6% GA (GA). Five mechanical parameters were measured: burst pressure, suture retention strength, ultimate tensile strength (UTS), ultimate strain (%), and Young's modulus. The tissues were also autologously re-embedded into the subcutaneous spaces of the same dogs for 4 weeks (n = 2) for the evaluation of histological responses. The burst pressure of the RAW group (1275.9 ± 254.0 mm Hg) was significantly lower than those of ET (2115.1 ± 262.2 mm Hg, p = 0.0298) and GA (2570.5 ± 282.6 mm Hg, p = 0.0017) groups. Suture retention strength, UTS or the ultimate strain did not differ significantly among the groups. Young's modulus of the ET group was the highest (RAW: 5.41 ± 1.16 MPa, ET: 12.28 ± 2.55 MPa, GA: 7.65 ± 1.18 MPa, p = 0.0185). No significant inflammatory tissue response or evidence of residual chemical toxicity was observed in samples implanted subcutaneously for four weeks. Therefore, short-duration ET and GA treatment might improve surgical handling and the mechanical properties of in vivo tissue-engineered vascular tissues to produce ideal grafts in terms of mechanical properties without interfering with histological responses.

Prediction for future occurrence of type A aortic dissection using computational fluid dynamics.

OBJECTIVES: The actual underlying mechanisms of acute type A aortic dissection (AAAD) are not well understood. The present study aimed to elucidate the mechanism of AAAD using computational fluid dynamics (CFD) analysis. METHODS: We performed CFD analysis using patient-specific computed tomography imaging in 3 healthy control cases and 3 patients with AAAD. From computed tomography images, we made a healthy control model or pre-dissection model for CFD analysis. Pulsatile cardiac flow during one cardiac cycle was simulated, and a three-dimensional flow streamline was visualized to evaluate flow velocity, wall shear stress and oscillatory shear index (OSI). RESULTS: In healthy controls, the transvalvular aortic flow was parallel to the ascending aorta. There was no spotty high OSI area at the ascending aorta. In pre-dissection patients, accelerated transvalvular aortic flow was towards the posterolateral ascending aorta. The vortex flow was observed on the side of the lesser curvature in mid-systole and expanded throughout the entire ascending aorta during diastole. Systolic wall shear stress was high due to the accelerated aortic blood flow on the side of the greater curvature of the ascending aorta. On the side of the lesser curvature, high OSI areas were observed around the vortex flow. In all pre-dissection cases, a spotty high OSI area was in close proximity to the actual primary entry site of the future AAAD. CONCLUSIONS: The pre-onset high OSI area with vortex flow is closely associated with the future primary entry site. Therefore, we can elucidate the mechanism of AAAD with CFD analysis.

Effects of Short-Duration Ethanol Dehydration on Mechanical Properties of Porcine Pericardium.

PURPOSE: Autologous pericardium is an ideal material for cardiovascular reconstruction including pulmonary artery plasty. Despite the fact that dehydration by ethanol has been used to improve its surgical handling, the effects of the ethanol on mechanical properties of the pericardium have not been previously investigated. The effects of short-duration ethanol dehydration on the mechanical properties of porcine pericardium were evaluated. METHODS: Porcine pericardia (n = 3) were separated into three groups: the raw group with no treatments (RAW), the group immersed in 70% ethanol for 10 min (ET group), and the group immersed in 0.6% glutaraldehyde for 10 min (GA). We measured five parameters of mechanical properties as specified in ISO 7198. RESULTS: ET treatment improved surgical handling as well as GA treatment. There were no significant differences in burst pressure (P = 0.639), suture retention strength (P = 0.529), ultimate tensile strength (UTS; P = 0.486), or Young's modulus (P = 0.408). Only the ultimate strain of the GA group was significantly higher among the three groups (RAW: 33.34% ± 2.02%, ET: 37.48% ± 1.84%, GA: 44.74% ± 2.87%; P = 0.046). CONCLUSIONS: Short-duration ethanol dehydration did not compromise its mechanical properties while maintaining its surgical handling improvements.

External Corset Technique in a Patient With Anomalous Artery Supply to the Left Basal Segment.

Postoperative aneurysmal formation of the anomalous artery stump has been reported in the systemic arterial supply to the basal segment of the left lung, whereas the effective preventive strategy remains unclear. Herein we report a case successfully treated with a new external corset technique of an anomalous artery stump. A 54-year-old man with a history of repeated hemoptysis underwent a left lower lobectomy. The anomalous artery stump with a 1.1 cm diameter was wrapped using woven Dacron vascular graft. No aneurysmal change has been observed in the computed tomography obtained after 3 years of follow-up.

Histology and Mechanics of In Vivo Tissue-Engineered Vascular Graft for Children.

PURPOSE: This study sought to evaluate the histologic and mechanical properties of autologous in vivo tissue-engineered vascular grafts (in vivo TEVGs) used for pediatric heart surgery. DESCRIPTION: Molds of in vivo TEVGs made of silicone drain tubes were embedded into subcutaneous spaces in 2 boys during their first operation and were used as patch materials to treat pulmonary artery stenosis during the second operation. The remaining pieces of the patches were evaluated histologically and mechanically. EVALUATION: In vivo TEVGs had very smooth luminal surfaces, and their walls mainly comprised collagen fibers and small numbers of fibroblasts. Mean wall thickness was 200 µm, mean suture retention strength was 2.26 N, and burst pressure was 3057 mm Hg. CONCLUSIONS: Human in vivo TEVGs mainly comprise collagen fibers, and their mechanical properties prove them safe for pulmonary arterioplasty. Therefore, human in vivo TEVGs may be promising alternatives to autologous pericardium for pediatric cardiovascular surgical procedures that often require multistage operations.

Symptomatic Ipsilateral Limb Twisting Due to Extensive Rotational Re-orientation of the C3 Excluder.

INTRODUCTION: Since the introduction of the Gore C3 device, which allows level re-positioning and contralateral gate cannulation, there have been very few reported complications due to excessive readjustment attempts. A case is reported of ipsilateral limb twisting and severe stenosis caused by extensive rotational re-orientation of the C3 system during a challenging intra-operative gate catheterisation. REPORT: Endovascular aortic aneurysm repair (EVAR) was performed for an infrarenal abdominal aortic aneurysm. Owing to difficulties encountered during contralateral gate cannulation using a Gore C3 device, the device was re-constrained and rotated clockwise several times, which induced twisting and severe symptomatic stenosis of the ipsilateral limb. The stenosed ipsilateral limb was successfully dilated with a bare stent two days after EVAR. DISCUSSION: Ipsilateral limb twisting due to extensive rotational re-orientation of the Gore C3 Excluder may occur during challenging intra-operative gate catheterisation. Thus, in cases that require extensive rotational re-orientation of the C3 system, it is advisable to carefully inspect for ipsilateral limb twisting during surgery.

[A Case of Aortic Graft Infection Due to Listeria monocytogenes Detected by Microarray-Based, Multiplexed, Automated Molecular Diagnosis System].

A 80-year-old man was transferred to our hospital for hemoptysis caused by erosion(perforation) of thoracic aortic stent graft infection into the airway. Blood cultures on admission detected Gram-positive rods, and a microarray-based, multiplexed, automated molecular diagnosis instrument (Verigene® system) identified Listeria spp. Although Listeria monocytogenes is rare organism of stent graft infection, we were able to start appropriate antibiotic therapy on the second hospital day due to rapid identification of bacteria. Verigene® system is considered to be useful in severe infectious diseases including stent graft infections, even if the causative organism is rare.

Development of xenogeneic decellularized biotubes for off-the-shelf applications.

In earlier studies, we developed in vivo tissue-engineered, autologous, small-caliber vascular grafts, called "biotubes," which withstand systemic blood pressure and exhibit excellent performance as small-caliber vascular prostheses in animal models. However, biotube preparation takes 4 weeks; therefore, biotubes cannot be applied in emergency situations. Moreover, for responses to various types of surgery, grafts should ideally be readily available in advance. The aim of this study was to develop novel, off-the-shelf, small-caliber vascular grafts by decellularizing in vivo tissue-engineered xenogeneic tubular materials. Silicone rod molds (diameter: 2 mm, length: 70 mm) placed in subcutaneous pouches of a beagle dog for 4 weeks were harvested with their surrounding connective tissues. Tubular connective tissues were obtained after pulling out the impregnated molds. Subsequently, they were decellularized by perfusion with sodium dodecyl sulfate and Triton X-100. They were stored as off-the-shelf grafts at -20°C for 1 week. The decellularized grafts derived from the beagle dog were xenogeneically transplanted to the abdominal aortas of rats (n = 3). No signs of abnormal inflammation or immunological problems due to the xenogeneic material were observed. Echocardiography confirmed the patency of the grafts at 1 month after implantation. Histological evaluation revealed that the grafts formed neointima on the luminal surface, and that the graft walls had cell infiltration. Little accumulation of CD68-positive macrophages in the graft wall was observed. Xenogeneic decellularized tubular tissues functioned as small-caliber vascular grafts, as well as autologous biotubes. This technology enables the easy fabrication of grafts from xenogeneic animals in advance and their storage for at least a week, satisfying the conditions for off-the-shelf grafts.

Effect of ß-blocker on maternal-fetal heart rates and coupling in pregnant mice and fetuses.

The aim of this preliminary study is to look how maternal-fetal heart rates and their coupling patterns are influenced by injection of ß blocker(propranolol) into pregnant mice. Total of 6 pregnant female mice were divided into two groups [control (N=3) and ß blockade (N=3)]. On 17.5-day mean heart rate of mothers and fetuses (MHR and FHR) were simultaneously measured for 20 minutes (10 minutes under normal condition and 10 minutes with saline (to control group) and propranolol (to the ß blockade group) solution by using an invasive maternal and fetal electrocardiogram techniques with needle electrodes. Results show that FHR decreased and maternal-fetal heart rate coupling (λ) patterns changed with propranolol infusion (no change with saline). Statistical test showed that changes (increase/decrease from pre to post values) in mean, rmssd and power spectral density (PSD) (2~4 Hz)) of MHR, short term variability of FHR, PSD (0.0~1.0 Hz) of FHR and λ were found to be significantly associated with treatment types (saline to propranolol). The presented results and protocol allow for assessment of ß adrenergic control of maternal and fetal heart, which will further enhance the value of the mouse as a model of heritable human pregnancy and hypertension.

Aortic Arch Pseudoaneurysm Associated With Chronic Trauma by Resected Edge of the Left Clavicle.

A 66-year-old man, who had a history of left lung and clavicle resection, was referred to us for aortic arch pseudoaneurysm. Resected edge of the left clavicle was attached to the anterior surface of the aortic arch. Patch repair of the pseudoaneurysm using hypothermic circulatory arrest was performed successfully. (Level of Difficulty: Intermediate.).

In Situ Graft Replacement for a Ruptured Abdominal Aortic Aneurysm Infected with Listeria monocytogenes after Endovascular Aneurysm Repair.

Listeria monocytogenes infection and rupture of the aneurysm sac, after endovascular aneurysm repair (EVAR), are both rare. We report the case of an 82-year-old man who presented with a ruptured aneurysm by infection with L. monocytogenes after EVAR. We successfully treated him by in situ reconstruction with a bifurcated expanded polytetrafluoroethylene (ePTFE) graft, with partial removal of the infected stent graft. At 30 months from the reoperation, the patient was in good health at home, with no symptoms of infection, and the gallium-67-citrate single-photon emission computed tomography/computed tomography (SPECT/CT) fusion images confirmed no fluid accumulation.

Regulation of maternal-fetal heart rates and coupling in mice fetuses.

The aim of this preliminary study is to investigate if there is any evidence of maternal-fetal heart rate coupling in mice fetuses and how the coupling patterns are regulated by vagal nervous system on beat by beat. Total of 6 pregnant female mice were divided into two groups [control (N=3) and vagal blockade (N=3)]. On 17.5-day beat-to-beat heart rates of mothers and fetuses (MHR and FHR) were simultaneously measured for 20 minutes (10 minutes under normal condition and 10 minutes with saline (to control group) and atropine (to the vagal blockade group)) solution by using an invasive maternal and fetal electrocardiogram techniques with needle electrodes. Results show that occasional strong maternal-fetal heart rate coupling (strength was measured by $\lambda$) appeared and its patterns changed with atropine infusion (no change with saline). Additionally, fisher's exact test shows that changes (increase/decrease from pre to post injection values) in mean, rmssd and power spectral density (PSD) (2~4 Hz) of MHR, rmssd FHR and PSD (2~4 Hz) of${\lambda }$were found to be significantly (p<0.05) associated with treatment types (saline/ atropine). The presented results and protocol allow for the first time in the assessment of autonomic regulation of maternal and fetal heart and their interactions, which will further enhance the value of the mouse as a murine model of heritable human pregnancy and perinatal complications due to maternal conditions.

Computational fluid dynamics simulation of the right subclavian artery cannulation.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of right subclavian artery cannulation using computational fluid dynamics. METHODS: Patient-specific models of the aortic arch were made with 4 patterns (1: normal aorta, 2: ascending aorta aneurysm, 3: distal arch aneurysm, 4: bovine arch) based on the computed tomography images. Right subclavian artery and ascending aorta cannulation models were created to simulate the physiologic pulsatile flow. Perfusion flow through the arterial cannula was set to 2.50 L/min (50% flow), 3.75 L/min (75% flow), and 5.0 L/min (100%), respectively, and a 3-dimensional movie was made of 1 cardiac cycle to evaluate the blood flow. RESULTS: In both 50% and 75% flow simulation with right subclavian artery cannulation, the blood streamline from the right subclavian artery produced retrograde flow of the brachiocephalic artery and antegrade flow of the right common carotid artery throughout the cardiac cycle in all cases. Right subclavian artery flow deflected ascending aorta flow to the descending aorta. Left-side supra-aortic branches were perfused by blood flow from both the right subclavian artery cannula and the aortic valve. The ascending aortic cannulation model showed that blood flow from the aortic valve reached all 3 supra-aortic vessels in systole. CONCLUSIONS: Right subclavian artery cannulation was cerebroprotective, especially on the right side.

First Successful Clinical Application of the In Vivo Tissue-Engineered Autologous Vascular Graft.

PURPOSE: The ideal material for pediatric pulmonary artery (PA) augmentation is autologous pericardium. However, its utility for multistaged operations is limited. In this study, we applied an in vivo tissue-engineered autologous Biotube graft to a patient with congenital heart disease for the first time. DESCRIPTION: For molds of the Biotubes, two silicone 19F drain tubes were embedded in the subcutaneous spaces of a 2-year-old girl with a diagnosis of pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries during palliative surgical procedures. When definitive repair was performed after 8 months, the implants were removed to prepare Biotubes, one of which was cut open and autologously implanted into the PA for patch augmentation. EVALUATION: Seven months after implantation, the Biotube patch-augmented PA tolerated balloon angioplasty (BAP) for residual stenosis of the peripheral PA. Computed tomography images after BAP showed the well-preserved shape of the Biotube patch-augmented PA. Neither aneurysm formation nor stenosis was observed. CONCLUSIONS: The safety and feasibility of Biotubes for pediatric PA patch augmentation are described. Because Biotubes are completely autologous, they may be ideal material for pediatric PA augmentation.