Dichloroacetate inhibits the degeneration of decellularized cardiovascular implants.

OBJECTIVES: Intima hyperplasia is a major issue of biological cardiovascular grafts resulting in progressive in vivo degeneration that particularly decreases the durability of coronary and peripheral vascular bypasses. Previously, dichloroacetate (DCA) has been reported to prevent the formation of hyperplastic intima in injured arteries. In this study, the effect of DCA on the neointima formation and degeneration of decellularized small-caliber implants was investigated in a rat model. METHODS: Donor rat aortic grafts (n = 22) were decellularized by a detergent-based technique, surface-coated with fibronectin (50 µl ml-1, 24 h incubation) and implanted via anastomoses to the infrarenal aorta of the recipients. Rats in the DCA group (n = 12) received DCA via drinking water during the whole follow-up period (0.75 g l-1), while rats without DCA treatment served as controls (n = 10). At 2 (n = 6 + 5) and 8 (n = 6 + 5) weeks, the grafts were explanted and examined by histology and immunofluorescence. RESULTS: Systemic DCA treatment inhibited neointima hyperplasia, resulting in a significantly reduced intima-to-media ratio (median 0.78 [interquartile range, 0.51-1.27] vs 1.49 [0.67-2.39] without DCA, P < 0.001). At 8 weeks, neointima calcification, as assessed by an established von Kossa staining-based score, was significantly decreased in the DCA group (0 [0-0.25] vs 0.63 [0.06-1.44] without DCA, P < 0.001). At 8 weeks, explanted grafts in both groups were luminally completely covered by an endothelial cell layer. In both groups, inflammatory cell markers (CD3, CD68) proved negative. CONCLUSIONS: Systemic DCA treatment reduces adverse neointima hyperplasia in decellularized small-caliber arterial grafts, while allowing for rapid re-endothelialization. Furthermore, DCA inhibits calcification of the implants.

Rupture of aneurysmal coronary-to-pulmonary artery fistula in a 96-year-old female; report of a case.

Coronary artery fistula (CAF) is a relatively rare congenital abnormality of the coronary arteries; typically, patients who undergo surgery for CAFs are relatively young because it is a congenital disease. Here we present a case of an aneurysmal coronary-to-pulmonary artery fistula rupture in a 96-year-old female. Considering her extreme high age and missing preoperative diagnostics, only local hemostasis without anatomical repair was performed but the patient is still doing well 1 year after the operation.

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.

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.

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.

Serum Neuron-Specific Enolase Level as Predictor of Neurologic Outcome after Aortic Surgery.

BACKGROUND: This study aimed to evaluate the significance of serum neuron-specific enolase (NSE) level as a predictor of neurologic injury in thoracic aortic surgery. METHODS: We neurologically assessed 60 consecutive patients who underwent thoracic aortic surgery for thoracic aortic aneurysm (n = 26) and aortic dissection (n = 34). Using moderate hypothermic circulatory arrest with antegrade cerebral perfusion, total arch replacement and hemiarch replacement were performed in 37 and 23 patients, respectively. Serum NSE levels in venous blood samples drawn before surgery and at 1 day after surgery were measured. Severity of neurologic injury was categorized as either uncomplicated (n = 48), temporary neurologic dysfunction (TND, n = 5), or permanent neurologic dysfunction (PND, n = 7). The extent of stroke was estimated on computed tomography or magnetic resonance imaging. RESULTS: The NSE level significantly differed among the three groups (PND > TND > uncomplicated) on the first postoperative day. Receiver-operating characteristic curve analysis showed that the cutoff value of NSE level was 34.14 ng/mL for neurologic injury (sensitivity, 0.769; specificity, 0.851) and 43.56 ng/mL for PND (sensitivity, 1.000; specificity, 0.963). The NSE level significantly correlated with the extent of stroke (r = 0.61, p < 0.001). CONCLUSION: Serum NSE level is a significant predictor of adverse neurologic outcomes and extent of stroke after thoracic aortic surgery.

Controlled autologous recellularization and inhibited degeneration of decellularized vascular implants by side-specific coating with stromal cell-derived factor 1α and fibronectin.

Optimized biocompatibility is crucial for the durability of cardiovascular implants. Previously, a combined coating with fibronectin (FN) and stromal cell-derived factor 1α (SDF1α) has been shown to accelerate the in vivo cellularization of synthetic vascular grafts and to reduce the calcification of biological pulmonary root grafts. In this study, we evaluate the effect of side-specific luminal SDF1α coating and adventitial FN coating on the in vivo cellularization and degeneration of decellularized rat aortic implants. Aortic arch vascular donor grafts were detergent-decellularized. The luminal graft surface was coated with SDF1α, while the adventitial surface was coated with FN. SDF1α-coated and uncoated grafts were infrarenally implanted (n = 20) in rats and followed up for up to eight weeks. Cellular intima population was accelerated by luminal SDF1α coating at two weeks (92.4 ± 2.95% versus 61.1 ± 6.51% in controls, p < 0.001). SDF1α coating inhibited neo-intimal hyperplasia, resulting in a significantly decreased intima-to-media ratio after eight weeks (0.62 ± 0.15 versus 1.35 ± 0.26 in controls, p < 0.05). Furthermore, at eight weeks, media calcification was significantly decreased in the SDF1α group as compared to the control group (area of calcification in proximal arch region 1092 ± 517 µm2 versus 11 814 ± 1883 µm2, p < 0.01). Luminal coating with SDF1α promotes early autologous intima recellularization in vivo and attenuates neo-intima hyperplasia as well as calcification of decellularized vascular grafts.

Influence of Laminin Coating on the Autologous In Vivo Recellularization of Decellularized Vascular Protheses.

Decellularization of non-autologous biological implants reduces the immune response against foreign tissue. Striving for in vivo repopulation of aortic prostheses with autologous cells, thereby improving the graft biocompatibility, we examined surface coating with laminin in a standardized rat implantation model. Detergent-decellularized aortic grafts from donor rats (n = 37) were coated with laminin and systemically implanted into Wistar rats. Uncoated implants served as controls. Implant re-colonization and remodeling were examined by scanning electron microscopy (n = 10), histology and immunohistology (n = 18). Laminin coating persisted over eight weeks. Two weeks after implantation, no relevant neoendothelium formation was observed, whereas it was covering the whole grafts after eight weeks, with a significant acceleration in the laminin group (p = 0.0048). Remarkably, the intima-to-media ratio, indicating adverse hyperplasia, was significantly diminished in the laminin group (p = 0.0149). No intergroup difference was detected in terms of medial recellularization (p = 0.2577). Alpha-smooth muscle actin-positive cells originating from the adventitial surface invaded the media in both groups to a similar extent. The amount of calcifying hydroxyapatite deposition in the intima and the media did not differ between the groups. Inflammatory cell markers (CD3 and CD68) proved negative in coated as well as uncoated decellularized implants. The coating of decellularized aortic implants with bioactive laminin caused an acceleration of the autologous recellularization and a reduction of the intima hyperplasia. Thereby, laminin coating seems to be a promising strategy to enhance the biocompatibility of tissue-engineered vascular implants.

Total arch replacement with bilateral extra-anatomical axillary artery bypass and frozen elephant trunk technique for Kommerell's diverticulum.

A Kommerell's diverticulum is a rare congenital aortic arch anomaly associated with a high rate of aortic rupture or dissection. Therefore, surgical or endovascular repair should be considered early. A 64-year-old man was incidentally found to have an aortic arch anomaly, Kommerell's diverticulum, with a right aberrant subclavian artery and distal arch aneurysm. Hybrid total arch replacement with bilateral extra-anatomical axillary artery bypass and frozen elephant trunk technique was performed. This particular surgical approach would be a treatment option for any type of Kommerell's diverticulum.

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.

Dramatic improvement of left ventricular function after switching the ventricular pacing site from the right ventricular apex to the left ventricular free wall via a left mini thoracotomy: a case report.

The case of a patient with pacemaker-induced cardiomyopathy in whom left ventricular (LV) function was dramatically improved after switching the ventricular pacing site from the right ventricular apex to the LV free wall via a left mini thoracotomy due to pacemaker-associated infective endocarditis (PAIE) is presented. Our experience suggests that a surgically implanted epicardial LV lead on the LV lateral wall can be a good alternative pacing site that preserves LV function, especially in patients with PAIE.

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.

Manual repositioning of lung hernia after minimally invasive cardiac surgery.

Minimally invasive cardiac surgery has recently become widespread because it has few disadvantages. However, lung hernia has been reported as a rare complication of minimally invasive cardiac surgery (MICS), and normally requiring additional surgical procedures. We describe herein a case of manual repositioning of lung hernia after MICS.

Open brachiocephalic artery stent for static obstruction caused by acute type A aortic dissection.

Brachiocephalic artery dissection complicated by acute type A aortic dissection occasionally causes cerebral malperfusion. Although immediate central aortic repair has been the standard treatment for aortic dissection, dissection in supra-aortic vessels frequently remains after the surgery. The residual brachiocephalic artery dissection is reported to be associated with late neurological events. Therefore, additional intervention for brachiocephalic artery dissection during central aortic repair should be considered in selected cases. In this report, we describe two cases requiring open brachiocephalic artery stenting simultaneous with central aortic repair. There were no neurological or stent induced complications at latest follow-up.

Transfer of a minimally invasive mitral valve repair program from a high-volume center to a very low volume center: how many cases are necessary to maintain acceptable results?

OBJECTIVE: To investigate whether minimally invasive mitral valve repair (MIMVR) can be transferred from a high-volume center into a very small volume center and to clarify how many cases are necessary for maintenance of this program, early outcomes of MIMVR in Asahikawa Medical University were compared with those results in patients operated by a single surgeon in Duesseldorf University Hospital. METHODS: Sixty-five patients who underwent MIMVR in Asahikawa Medical University (group A) between May 2014 and July 2018 and 134 patients who underwent MIMVR in Duesseldorf University Hospital (group D) between September 2009 and January 2014 by a surgeon who started MIMVS later in Asahikawa were retrospectively analyzed. RESULTS: In group D, there were more patients with ischemic mitral valve regurgitation and with annular calcification than in group A. Survival rate at 6 months and 1 year was 98.5% and 98.5% in group A and 92.9% and 91.3% in group D, respectively. EuroSCORE II was significantly higher in patients dead within 30 days and within the first year. CONCLUSIONS: The present study demonstrated that MIMVR programs can be transferred with acceptable early results into very low volume centers, if the team is developed by surgeons who are well trained and experienced in MIMVR. Moreover, the present study suggested that case number for maintenance of acceptable results may be obviously less than the previous recognition that this kind of specialized surgery could be maintained with at least 50 cases annually. However, meticulous preparations for surgery are essential for satisfactory surgical outcomes.

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.