Polyvinyl alcohol coating prevents platelet adsorption and improves mechanical property of polycaprolactone-based small-caliber vascular graft.

The low patency of synthetic vascular grafts hinders their practical applicability. Polyvinyl alcohol (PVA) is a non-toxic, highly hydrophilic polymer; thus, we created a PVA-coated polycaprolactone (PCL) nanofiber vascular graft (PVA-PCL graft). In this study, we examine whether PVA could improve the hydrophilicity of PCL grafts and evaluate its in vivo performance using a rat aorta implantation model. A PCL graft with an inner diameter of 1 mm is created using electrospinning (control). The PCL nanofibers are coated with PVA, resulting in a PVA-PCL graft. Mechanical property tests demonstrate that the PVA coating significantly increases the stiffness and resilience of the PCL graft. The PVA-PCL surface exhibits a much smaller sessile drop contact angle when compared with that of the control, indicating that the PVA coating has hydrophilic properties. Additionally, the PVA-PCL graft shows significantly less platelet adsorption than the control. The proposed PVA-PCL graft is implanted into the rat's abdominal aorta, and its in vivo performance is tested at 8 weeks. The patency rate is 83.3% (10/12). The histological analysis demonstrates autologous cell engraftment on and inside the scaffold, as well as CD31/α-smooth muscle positive neointima regeneration on the graft lumen. Thus, the PVA-PCL grafts exhibit biocompatibility in the rat model, which suggests that the PVA coating is a promising approach for functionalizing PCL.

Insulin therapy maintains the performance of PVA-coated PCL grafts in a diabetic rat model.

Vascular tissue engineering has shown promising results in "healthy" animal models. However, studies on the efficacy of artificial grafts under "pathological conditions" are limited. Therefore, in this study, we aimed to characterize the performance of polyvinyl alcohol (PVA)-coated poly-ε-caprolactone (PCL) grafts (PVA-PCL grafts) under diabetic conditions. To this end, PCL grafts were produced via electrospinning and coated with the hydrophilic PVA polymer, while a diabetic rat model (DM) was established via streptozotocin injection. Thereafter, the performance of the graft in the infrarenal abdominal aorta of the rats was evaluated in vivo. Thus, we observed that the healthy group showed CD31 positive/αSM positive cells in the graft lumen. Further, the patency rate of the PVA-PCL graft was 100% at 2 weeks (n = 7), while all the DM rats (n = 8) showed occluded grafts. However, the treatment of DM rats with neutral protamine Hagedorn insulin (tDM) significantly improved the patency rate (100%; n = 5). Furthermore, the intimal coverage rate corresponding to the tDM group was comparable to that of the healthy group at 2 weeks (tDM vs. healthy: 16.1% vs. 14.7%, p = 0.931). Therefore, the present study demonstrated that the performance of the PVA-PCL grafts was impaired in DM rats; however, insulin treatment reversed this impairment. These findings highlighted the importance of using a model that more closely resembles the cases that are encountered in clinical practice to achieve a clinically applicable vascular graft with a small diameter.

The Impact of Chronic Limb-Threatening Ischemia on Cardiac Surgery.

Purpose: The effect of chronic limb threatening ischemia (CLTI) on advanced cardiac disease, which requires surgical treatment, has rarely been reported. The purpose of this study was to review the outcomes of cardiac surgery in patients with CLTI and determine the risk factors, with a particular focus on the severity of CLTI. Patients: The baseline characteristics and outcomes of 33 patients who were treated for CLTI and underwent cardiac surgery were retrospectively analyzed. The states of CLTI were evaluated based on the Wound, Ischemia, and foot Infection (WIfI) classification system, and 33 patients were divided into the low-WIfI group (stages 1-2, n = 13) and high-WIfI group (stages 3-4, n = 20). Results: The in-hospital mortality rate was 0% in low-WIfI group and 35% in high-WIfI group (p = 0.027). Postoperative complications, particularly severe infections, occurred more frequently among high-WIfI group than low-WIfI group (70.0% vs. 23.1%, p < 0.01). Multivariable analysis identified foot infection grade as a WIfI classification factor and lower albumin levels as factors significantly associated with postoperative complications. The 1-year and 2-year survival rates were 84.6% and 67.7% in low-WIfI group and 45% and 28.1% in high-WIfI group, respectively (p = 0.011). Conclusions: Cardiac surgery in patients with high WIfI stage was an extremely high-risk procedure. In such patients, lowering the WIfI stage by lower extremity revascularization and/or debridement of diseased parts prior to cardiac surgery can be considered.

Feasibility of the AtriClip Pro Left Atrium Appendage Elimination Device via the Transverse Sinus in Minimally Invasive Mitral Valve Surgery.

BACKGROUND: Achieving external access to and manual occlusion of the left atrial appendage (LAA) during minimally invasive mitral valve surgery (MIMVS) through a small right thoracotomy is difficult. Occlusion of the LAA using an epicardial closure device seems quite useful compared to other surgical techniques. METHODS: Fourteen patients with atrial fibrillation underwent MIMVS with concomitant surgical occlusion of the LAA using double-layered endocardial closure stitches (n=6, endocardial suture group) or the AtriClip Pro closure device (n=8, AtriClip group) at our institution. The primary safety endpoint was any device-related adverse event, and the primary efficacy endpoint was successful complete occlusion of blood flow into the LAA as assessed by transthoracic echocardiography at hospital discharge. The primary efficacy endpoint for stroke reduction was the occurrence of ischemic or hemorrhagic neurologic events. RESULTS: All patients underwent LAA occlusion as scheduled. The cardiopulmonary bypass and aortic cross-clamp times in the endocardial suture group and the AtriClip group were 202±39 and 128±41 minutes, and 213±53 and 136±44 minutes, respectively (p=0.68, p=0.73). No patients in either group experienced any device-related serious adverse events, incomplete LAA occlusion, early postoperative stroke, or neurologic complication. CONCLUSION: Epicardial LAA occlusion using the AtriClip Pro during MIMVS in patients with mitral valve disease and atrial fibrillation is a simple, safe, and effective adjunctive procedure.

Descending aortic transection for recurrence of a pseudoaneurysm previously treated with a stent graft after extra-anatomical bypass for aortic coarctation: a case report.

BACKGROUND: In adult patients with primary or recurrent coarctation of the aorta (CoA), extra-anatomic bypass grafting (EABG) has been widely used as a surgical treatment option. However, there have been few reports on pseudoaneurysms (PAs) of the distal anastomotic sites after extra-anatomic bypass for CoA. CASE PRESENTATION: A 51-year-old man with hemoptysis was transferred to our hospital. Twenty years ago, he had undergone EABG from the ascending to the descending aorta (ascending-to-descending EABG) for CoA with right aortic arch. Eight years ago, he underwent thoracic endovascular aortic repair (TEVAR) for the ruptured PA on the distal anastomotic site of the EABG. Contrast-enhanced computed tomography scans revealed recurrent ruptured PA on the distal anastomotic site of the EABG. Therefore, we decided to replace the descending aorta, followed by end-to-side anastomosis of the EABG to the replaced descending aorta. However, due to massive adhesion of the lung to the EABG and PA, we performed transection of the descending aorta to decompress the PA. The postoperative course was uneventful, and the patient is doing well 5 months after surgery. CONCLUSIONS: Aortic transection between the CoA and the distal anastomosis site may be a useful additional procedure in patients previously treated with TEVAR for PAs in the distal anastomosis site after EABG.

Proximalized Total Arch Replacement Can Be Safely Performed by Trainee.

BACKGROUND: The aim of the present study was to validate safety of total arch replacement (TAR) using a novel frozen elephant trunk device, operated by trainees as surgical education. METHODS: Sixty-four patients including 19 patients (29.6%) with acute aortic dissection type A (AADA) underwent TAR in our institute between April 2014 and March 2019 were retrospectively analyzed. Twenty-nine patients were operated by trainees (group T) and 35 patients were operated by attending surgeons (group A). RESULTS: Patient characteristics did not differ between groups. Operative time (409.4 ± 87.8 vs. 468.6 ± 129.6 minutes, p = 0.034), cardiopulmonary bypass time (177.7 ± 50.4 vs. 222.9 ± 596.7 minutes, p = 0.019), and hypothermic circulatory arrest time (39.5 ± 13.4 vs. 54.5 ± 18.5 minutes, p = 0.001) were significantly shorter in group A than in group T, but aortic clamping time did not differ between groups (115.3 ± 55.7 vs. 114.2 ± 35.0 minutes, p = 0.924) because the rate of concomitant surgery was higher in group A (37.1 vs. 10.3%, p = 0.014). Thirty-day mortality was 3.1% in the entire cohort. Although operation time was longer in group T, there were no significant difference in postoperative results between the groups, and the experience levels of the main operator were not independent predictors for in-hospital mortality + major postoperative complications. There was no difference in late death and aortic events between groups. CONCLUSIONS: The present study demonstrated that TAR can be safely performed by trainees, and suggests TAR as a possible and safe educational operation.

Aorto-Right Atrial Fistula after Minimally Invasive Tricuspid Valve Repair: A Report of Two Cases.

We experienced two cases of postoperative iatrogenic aorto-right atrial fistula (ARAF) after tricuspid valve repair (TVR) using minimally invasive cardiac surgery (MICS) technique. In both the cases, the flow of ARAF passed through the sinus of Valsalva near the noncoronary cusp (NCC)/right coronary cusp (RCC) commissure or NCC to right atrium. The quality of the fine needle used in the MICS technique may be inferior to that used in conventional surgery; ARAF after TVR could be a unique pitfall with the MICS technique.

Impella CP for treatment of left ventricular free-wall rupture after myocardial infarction: Report of a case.

Unloading of the left ventricle (LV) is essential for the treatment of LV free-wall rupture (LVFWR), and it is well-known that the LV can be optimally unloaded with the Impella system. However, there has been no report on applying the Impella system for the treatment of LVFWR. Here, we report a patient with FWR after massive myocardial infarction who was successfully treated with non-suture repair via median sternotomy and implantation of Impella CP (Abiomed, Danvers, MA).

The Cause of Massive Hemoptysis After Thoracic Endovascular Aortic Repair May Not Always Be an Aortobronchial Fistula: Report of a Case.

Hemoptysis after thoracic endovascular/open aortic repair is relatively rare but a well-known complication, and normally diagnosed with aortobronchial fistula (ABF). Here, we present a patient who suffered from recurrent massive hemoptyses even after multiple thoracic endovascular aortic repairs (TEVARs), where hemoptysis was ultimately controlled by pneumonectomy. In this case, the bleeding source was not the aorta but the lung parenchyma itself, indicating the importance of raising awareness that the cause of massive hemoptysis after TEVAR may not always be an ABF.

Sutureless technique using the left atrial appendage for left pulmonary vein occlusion after catheter ablation.

BACKGROUND: Pulmonary vein stenosis or occlusion is a rare but one of the most devastating complications after catheter ablation for cardiac arrhythmias, and surgical repair is an option in severe cases. The sutureless technique, which avoids direct suture of vessel walls, was initially described for congenital pulmonary vein stenosis and has been widely performed due to its good restenosis-free rate. CASE PRESENTATION: A 52-year-old male developed left pulmonary vein occlusion after catheter ablation for atrial fibrillation. The surgical repair with sutureless technique using the left atrial appendage was performed without any complications. Postoperative computed tomography demonstrated the revascularization of the pulmonary vein. CONCLUSIONS: The sutureless technique using the left atrial appendage is significantly reasonable particularly in case of left pulmonary vein stenosis or occlusion after catheter ablation for atrial fibrillation since it reduces the risks of restenosis and thromboembolism.

Examination of Anterior Leaflet Pseudoprolapse Causing Severe Mitral Regurgitation and Its Ideal Surgical Procedure.

BACKGROUND: The aim of this study is to evaluate severe mitral regurgitation caused by so called atrial leaflet "pseudoprolapse" and verify the effect of simple annular stabilization. METHODS: One-hundred-twenty-two patients underwent surgery for severe mitral regurgitation at our institute between January 2015 to July 2018. Of those, 32 cases diagnosed as anterior leaflet prolapse that underwent mitral repair were analyzed. Ten cases with pseudoprolapse, which is defined as anterior leaflet prolapse without dropping into the left atrium beyond the annular line causing eccentric regurgitation flow directed to the posterior atrium, were classified as the Pseudoprolapse Group. The other 22 cases had obvious anterior leaflet prolapse dropping into the left atrium; these cases were classified as the True Prolapse Group. We compared clinical findings between the 2 groups and reviewed pseudoprolapse cases. RESULTS: Patients in the Pseudoprolapse Group had lower ejection fraction and lower regurgitation volume than those in the True Prolapse Group. A2 lesion as main inflow of regurgitation was more included in the Pseudoprolapse Group. All but one patient in the Pseudoprolapse Group received only simple annuloplasty, and all patients in the True Prolapse Group received leaflet repair and annuloplasty. In both groups, mid-term regurgitation grade and the reoperation rate were satisfactory. In the Pseudoprolapse Group, 6 cases were clarified as atrial functional mitral regurgitation, and 4 cases were considered to have focal posterior leaflet tethering. CONCLUSIONS: Pseudoprolapse cases could be characterized by low ejection fraction, low regurgitation volume, and A2 prolapse. For most cases with pseudoprolapse, simple annuloplasty may be enough, however further study is needed.

Pulmonary artery banding for initial treatment of ventricular septal rupture.

Ventricular septal rupture (VSR) is a serious and fatal mechanical complication after acute myocardial infarction. Emergent or urgent, surgical/transcatheter intervention is necessary to treat VSR, though the outcome is not favorable. We performed temporary pulmonary artery banding (PAB) in an 85-year-old man who presented with chest pain to adjust the shunt flow through the VSR, which prevented further pulmonary edema and delayed the timing of surgical repair. There has been no report showing successful PAB performed for VSR after myocardial infarction.

Routine postoperative computed tomography is superior to cardiac ultrasonography for predicting delayed cardiac tamponade.

Delayed cardiac tamponade (DCT) can be a fatal complication after cardiac surgery, but its early diagnosis and/or prediction is sometimes difficult. This study aimed to confirm the efficacy of postoperative computed tomography (CT) as routine examination compared with transthoracic echocardiography (TTE) for predicting DCT after cardiac surgery. This study was a retrospective single-center analysis of 485 consecutive patients undergoing cardiac surgery from January 2016 to July 2018 in our department. Among them, 237 patients were enrolled in this analysis after application of the exclusion criteria: minimally invasive surgery via small thoracotomy, death in the acute phase, and no CT 7 ± 3 days after surgery. Pericardial effusion (PE) was measured at the thickest part using CT and TTE. DCT was found in nine enrolled patients (3.8%). The mean PE on CT was 7.7 ± 5.5 mm in the no event group and 23.4 ± 5.7 mm in the DCT group (p = 0.026), whereas the mean PE on TTE was 6.2 ± 4.5 mm in the no event group and 10.8 ± 4.4 mm in the DCT group (p = 0.170). On multivariate analysis, PE greater than 20 mm on CT (Odds ratio, 13.93; 95% confidence interval 2.57-75.46; p = 0.002) was a significant predictor of DCT. The present study suggested that postoperative CT examination is superior to TTE for predicting DCT. If PE is less than 20 mm on CT, it could be treated conservatively; otherwise, preventive/therapeutic intervention should be considered.

Vascular Tissue Engineering: Polymers and Methodologies for Small Caliber Vascular Grafts.

Cardiovascular disease is the most common cause of death in the world. In severe cases, replacement or revascularization using vascular grafts are the treatment options. While several synthetic vascular grafts are clinically used with common approval for medium to large-caliber vessels, autologous vascular grafts are the only options clinically approved for small-caliber revascularizations. Autologous grafts have, however, some limitations in quantity and quality, and cause an invasiveness to patients when harvested. Therefore, the development of small-caliber synthetic vascular grafts (<5 mm) has been urged. Since small-caliber synthetic grafts made from the same materials as middle and large-caliber grafts have poor patency rates due to thrombus formation and intimal hyperplasia within the graft, newly innovative methodologies with vascular tissue engineering such as electrospinning, decellularization, lyophilization, and 3D printing, and novel polymers have been developed. This review article represents topics on the methodologies used in the development of scaffold-based vascular grafts and the polymers used in vitro and in vivo.

Delayed thoracic wall bleeding after minimally invasive mitral valve repair.

The first case of late thoracic wall bleeding after minimally invasive mitral valve repair treated by endovascular therapy is reported. A 55-year-old woman underwent mitral valve repair and tricuspid annuloplasty through a mini-thoracotomy approach. Her postoperative course was uneventful until she had anemia one week after the surgery. Contrast-enhanced computed tomography showed right hemothorax due to bleeding from a branch of the right lateral thoracic artery. Endovascular coil embolization and gelatin sponge injection were performed. The patient was discharged without any complications on postoperative day 20.

A case of pulmonary artery sarcoma that was initially mis-diagnosed as pulmonary embolism.

Pulmonary artery sarcoma is a rare and highly malignant neoplasm. Early diagnosis and a multidisciplinary approach including surgical treatment and optimal medical therapy could prolong survival. Since the clinical symptoms and imaging findings of pulmonary artery sarcoma mimic pulmonary embolism, definitive diagnosis and surgical intervention are often delayed. In this report, a case of pulmonary artery sarcoma that was initially misdiagnosed as pulmonary embolism is presented.

Coronary-Pulmonary Artery Fistula Ligation and Mitral Valve Repair Through a Mini-Thoracotomy Approach.

A 39-year-old man with severe mitral regurgitation was referred to our institution for surgical evaluation. During preoperative workup, a coronary-pulmonary artery fistula was incidentally found by computed tomography. After multidisciplinary cardiac team discussion, the decision was made to proceed with coronary-pulmonary artery fistula ligation and mitral valve repair through a mini-thoracotomy approach. Cardiopulmonary bypass was initiated with femoral vessels. A mini-thoracotomy was made in the fourth intercostal space. First, mitral valve repair with posterior leaflet folding and ring annuloplasty was done. The coronary-pulmonary artery fistula was running on the roof of the left atrium and was ligated with metal clips under thoracoscopic vision. Postoperative computed tomography showed no residual fistula.

Failed transcatheter pulmonary artery embolization in a patient suffering from massive hemoptysis after thoracic endovascular aortic repair.

An emergency thoracic endovascular aortic repair (TEVAR) with zone 2 landing without revascularization of the left subclavian artery was performed due to the impending rupture of a distal arch aneurysm in an old patient presenting hemoptysis. Two months later, the patient had recurrent massive hemoptyses and continued after additional zone 0 TEVAR. The lung parenchyma was considered to be the bleeding source and transcatheter pulmonary artery embolization was performed, and the episodes of massive hemoptysis appeared to have ceased. However, the patient died of sudden recurrent massive hemoptysis 40 days later. Inflammation and/or infection of the lung parenchyma adjunct to the aortic aneurysm could be cause of fatal hemoptysis, and aggressive therapy such as lung resection should be considered in such patients.

[Ruptured Left Ventricular Pseudoaneurysm Representing Cardiac Tamponade;Report of a Case].

A 64-year-old woman was followed by the other hospital because of left ventricular false aneurysm after percutaneous coronary intervention for acute myocardial infarction of which culprit lesion was left circumflex artery. She admitted to the hospital suffering from nausea and dyspnea. Echocardiography showed huge pericardial effusion and cardiac tamponade due to ruptured left ventricular false aneurysm and transferred to our hospital under pericardial drainage. She presented with symptoms such as shock, so we performed emergent left ventricular reconstruction. She uneventfully left our hospital on 18 post-operative day.