Yoshinori Ohtsu

Stimulation of P19CL6 with multiple reagents induces pulsating particles in vivo

ABSTRACT Objective: Injection of stem cells into ischaemic areas of the heart is expected to be an effective method for myocardial regeneration. The embryogenic carcinoma (EC) cell line P19CL6 is known to differentiate into cardiomyocytes when cultured with dimethyl sulfoxide (DMSO) and is expected to be a promising source for regenerative therapy in cardiac disease. To establish a high-yield method of cardiomyocyte differentiation, P19CL6 cells were double-stimulated with 5‐azacytidine. Double stimulation-induced cardiomyocytes were also transplanted into ectopic sites in mice and their function evaluated. Methods and results: To induce differentiation under adherent conditions, P19CL6 cells were incubated in growth medium with 10 µM 5‐azacytidine for 24 h. After 5‐azacytidine treatment, P19CL6 cells were incubated with 1% DMSO for nine days until they began to pulsate. Prior to transplantation, cells were treated again with 5‐azacytidine. Differentiated cells were injected into the greater omentum, para-aorta region of the retroperitoneum and peri-femoral artery of adult BALB/c nude mice. Nine days after transplantation, irregularly pulsating tissues at a rate slower than the host heart were observed in the transplanted sites. Light microscopy showed formation of cardiac muscle tissues originating from P19CL6 cells. Differentiated cardiomyocytes were positive for cardiac troponin I, cadherin and α-smooth muscle actin, and the expressions of Csx/Nkx2.5 and GATA4 mRNAs were up-regulated. Electron microscopy demonstrated components specific to cardiomyocytes, such as Z-bands, desmosomes, fasciae adherens, myofibrils and mitochondria, which confirmed successful heterotopic cardiac muscle differentiation from P19CL6 cells. Conclusion: This study demonstrated high-yield cardiac muscle differentiation of P19CL6 by 5‐azacytidine and DMSO double stimulation and successful formation of cardiac muscle-like tissue by ectopic transplantation of cardiomyocytes derived from P19CL6 into the retroperitoneal area as well as into the peripheral vessel area.

Prosthetic valve endocarditis caused by Staphylococcus capitis: report of 4 cases

Although Staphylococcus capitis is considered to be a rare causative organism for prosthetic valve endocarditis, we report 4 such cases that were encountered at our hospital over the past 2 years. Case 1 was a 79-year-old woman who underwent aortic valve replacement with a bioprosthetic valve and presented with fever 24 days later. Transesophageal echocardiography revealed an annular abscess in the aorto-mitral continuity and mild perivalvular regurgitation. We performed emergency surgery 5 days after the diagnosis of prosthetic valve endocarditis was made. Case 2 was a 79-year-old woman presenting with fever 40 days after aortic valve replacement with a bioprosthesis. Transesophageal echocardiography showed vegetation on the valve, and she underwent urgent surgery 2 days after prosthetic valve endocarditis was diagnosed. In case 3, a 76-year-old man presented with fever 53 days after aortic valve replacement with a bioprosthesis. Vegetation on the prosthetic leaflet could be seen by transesophageal echocardiography. He underwent emergency surgery 2 days after the diagnosis of prosthetic valve endocarditis was made. Case 4 was a 68-year-old woman who collapsed at her home 106 days after aortic and mitral valve replacement with bioprosthetic valves. Percutaneous cardiopulmonary support was started immediately after massive mitral regurgitation due to prosthetic valve detachment was revealed by transesophageal echocardiography. She was transferred to our hospital by helicopter and received surgery immediately on arrival. In all cases, we re-implanted another bioprosthesis after removal of the infected valve and annular debridement. All patients recovered without severe complications after 2 months of antibiotic treatment, and none experienced re-infection during 163 to 630 days of observation. Since the time interval between diagnosis of prosthetic valve endocarditis and valve re-replacement ranged from 0 to 5 days, early surgical removal of the infected prosthesis and an appropriate course of antibiotics were attributed to good clinical outcomes in our cases.

Tracheo-Bronchial Obstruction and Esophageal Perforation after TEVAR for Thoracic Aortic Rupture.

A 67-year-old man was referred to our hospital for an ascending aortic aneurysm, thoracoabdominal aortic aneurysm and aortic regurgitation. Graft repair of the thoracic aortic arch and aortic valve replacement was given priority and completed, however he developed descending aortic rupture before the second scheduled surgery, and endovascular stent grafting was performed. He subsequently developed tracheobronchial obstruction and esophageal perforation. The patient underwent urgent esophagectomy and enterostomy with continuity later reestablished. However, he died of sepsis 5 months after surgery. Despite the less invasive nature of endovascular treatment, esophageal perforation can nevertheless occur and postoperative vigilance is well warranted.

Surgical Repair of Cervical Aortic Arch With Brain Circulation Anomaly Through Clamshell Incision

We report the successful surgical repair of a cervical aortic arch and diverticulum with a brain circulation anomaly through a clamshell incision. Because of the reliability of selective antegrade cerebral perfusion and superior exposure, we chose an approach through a clamshell incision. We describe the utility of this approach for treating a cervical aortic arch with a diverticulum.

Delayed Esophageal Perforation Secondary to Thoracic Aortic Aneurysm Rupture in a Patient with Human Immunodeficiency Virus Infection

A 65-year-old man infected with human immunodeficiency virus underwent emergency surgery for rupture of a mycotic descending thoracic aneurysm. The aneurysm was replaced with a prosthetic graft wrapped with omentum. Esophageal perforation occurred 3 weeks after surgery. The patients condition remained stable, and we adopted a conservative treatment. The esophageal fistula had not healed completely and a biopsy of the scar revealed gastric cancer. We performed a distal gastrectomy, Roux-Y reconstruction, and enterostomy for enteral feeding. Follow-up endoscopy revealed healing of the fistula, and the patient was eventually discharged. We managed this potentially fatal complication with minimally invasive treatment.

Creatine phosphokinase did not increase after on-pump beating heart coronary artery bypass graft early after acute myocardial infarction

Aims: Emergency coronary artery bypass grafting (CABG) is sometimes mandatory although operative mortality is high within 24 hours after the onset of acute myocardial infarction (AMI). We have used on-pump beating heart (OPBH) CABG to reduce injury to non-infarcted myocardium during CABG. We compared clinical outcomes of OPBH with those of conventional CABG with cardiac arrest (OPCA), both performed within 24 hours after the onset of AMI. Methods: Twenty-two patients were enrolled in this study. Patients’ basic characteristics, operative procedure, in-hospital mortality, morbidity and changes in creatine phosphokinase (CPK) and myocardial subset of CPK (creatine phosphokinase-myoglobin binding, CPK-MB) and ejection fraction (EF) were retrospectively obtained by reviewing hospital records. Results: In the OPCA group, postoperative increases were seen in mean CPK (p=0.03) and in CPK-MB (p=0.03). In the OPBH group, postoperative decreases were seen in mean CPK (p=0.43) and in CPK-MB (p=0.07). Ejection fraction increased postoperatively in both groups, although the increase in OPCA was not significant. No statistically significant differences were found in mortality and morbidity between OPCA and OPBH. Conclusion: In our study, OPBH did not increase CPK and CPK-MB in early AMI treatment, suggesting that OPBH may reduce myocardial injury during CABG performed very early after AMI although further studies including randomized trial are warranted.

Early results of aortic root reoperation

Background Reoperation of aortic root is considered challenging because of technical difficulty and relatively low incidence of surgical indications. It is still not clear whether the redo root surgery could be performed safely although the primary Bentall procedure is a safe and established operation for aortic root surgery. We evaluated early outcomes of reaortic root replacement comparing to primary Bentall operation.

Indicators of survival after open repair of ruptured abdominal aortic aneurysms and an index for predicting aneurysmal rupture potential.

BACKGROUND The aims of this study were to assess variables associated with survival in patients undergoing ruptured abdominal aortic aneurysm (RAAA) repair and to develop an index other than the aneurysmal diameter to predict rupture potential. METHODS This study included 43 consecutive patients who underwent open surgery for RAAAs. RESULTS The mortality rate was 18.6% (8/43). The ratio between the maximum aneurysmal diameter and the length (along the central axis) from the aneurysmal neck to the point at which the diameter was three-fourth of the maximum aneurysmal diameter was used as an index to predict aneurysmal rupture potential. The index score was 2.7 ± 1.2 in the RAAA and 1.9 ± 0.9 in the EAAA (p = 0.018). For aneurysms of ≤ 6-cm diameter, the index score was 3.0 ± 1.0 in the RAAA and 1.8 ± 0.9 in the EAAA (p = 0.03). All patients in the EAAA except one had an index score of < 2.3 and 6 of the 7 patients with RAAA had a score of > 3. CONCLUSIONS The results suggest that patients with AAA having scores of > 3 are at high risk of rupture. This index would be useful for decision making regarding repair of AAA, especially in the borderline cases.