[New Intracoronary Shunt Cannula in Off-pump Coronary Artery Bypass Grafting].

In off-pump coronary artery bypass grafting(OPCAB), a bloodless operative field has great influence on the quality of anastomosis. In addition, maintenance of distal coronary flow during anastomosis stabilizes hemodynamics. We introduced a new intracoronary shunt cannula, Mini Shunt Pro (MSP). MSP adopts the step-tip, which allows easy insertion and reduces the risk of intimal injury. The distal and proximal sides of the tips of MSP are 0.25 mm different in diameter, which improves its fitness to the coronary artery and enhances a bloodless operative field. This new shunt cannula is considered to be safe and useful for high-quality anastomosis in OPCAB.

The impact of preoperative identification of the Adamkiewicz artery on descending and thoracoabdominal aortic repair.

OBJECTIVE: To investigate the impact of preoperative identification of the Adamkiewicz artery (AKA) on prevention of spinal cord injury (SCI) through the multicenter Japanese Study of Spinal Cord Protection in Descending and Thoracoabdominal Aortic Repair (JASPAR) registry. METHODS: Between January 2000 and October 2011, 2435 descending/thoracoabdominal aortic repairs were performed, including 1998 elective repairs and 437 urgent repairs, in 14 major centers in Japan. The mean patient age was 67 ± 13 years, and 74.2% were males. There were 1471 open repairs (ORs), including 748 descending and 137 thoracoabdominal extent [Ex] I, 136 Ex II, 194 Ex III, 115 Ex IV, and 138 Ex V, and 964 endovascular repairs (EVRs). Of the 2435 patients, 1252 (51%) underwent preoperative magnetic resonance or computed tomography angiography to identify the AKA. RESULTS: The AKA was identified in 1096 of the 1252 patients who underwent preoperative imaging (87.6%). Hospital mortality was 9.2% (n = 136) in those who underwent OR and 6.4% (n = 62) in those who underwent EVR. The incidence of SCI was 7.3% in the OR group (descending, 4.2%; Ex I, 9.4%; Ex II, 14.0%; Ex III, 14.4%; Ex IV, 4.2 %; Ex V, 7.2%) and 2.9% in the EVR group. The risk factors for SCI in ORs were advanced age, extended repair, emergency, and occluded bilateral hypogastric arteries. In ORs of the aortic segment involving the AKA, having no AKA reconstruction was a significant risk factor for SCI (odds ratio, 2.79, 95% confidence interval, 1.14-6.79; P = .024). CONCLUSIONS: In descending/thoracoabdominal aortic repairs, preoperative AKA identification with its adequate reconstruction or preservation, especially, in ORs of aortic pathologies involving the AKA, would be a useful adjunct for more secure spinal cord protection.

Utility of three-dimensional transesophageal echocardiography for diagnosis of unroofed coronary sinus.

We report a case of unroofed coronary sinus (URCS) in a 42-year-old female. At an outpatient clinic, she was found to have an atrioventricular septal defect and mitral regurgitation with pulmonary hypertension, and she was transferred to our institute for surgical treatment. Both atrioventricular valves were located at the same level, and both the right atrium (RA) and right ventricle were enlarged on two-dimensional transthoracic echocardiography. Color Doppler imaging demonstrated severe mitral and tricuspid regurgitation and a left-to-right shunt from the left atrium (LA) to the RA. Although an ostium primum defect of the atrial septum was suspected, the exact position of the shunt flow was unclear. Two-dimensional transesophageal echocardiography (2D-TEE) could visualize a direct communication between the LA and coronary sinus. Three-dimensional transesophageal echocardiography (3D-TEE) clearly visualized the entire route from the coronary sinus into the LA and RA. The utility of 3D-TEE as a modality complementary to 2D-TEE in diagnosis of URCS was confirmed.

Successful diagnosis of pericardial rupture caused by blunt chest trauma using contrast ultrasonography.

A 65-year-old male developed acute myocardial infarction due to coronary artery dissection and tricuspid valve injury after blunt chest trauma. Acute myocardial infarction was treated by coronary artery intervention; however, refractory heart failure with pleural effusion remained. The first transthoracic echocardiography (TTE) on admission failed to clearly visualize the tricuspid valve and right ventricle due to poor image quality. A follow-up TTE with contrast ultrasonography revealed pericardial rupture in addition to tricuspid regurgitation. Ruptures of the tricuspid papillary muscle and pericardium were confirmed during surgery and were repaired successfully. Blunt chest trauma results in various cardiac injuries including cardiac rupture, intramural hematoma, valvular injury, coronary artery injury, and electrical disturbances, leading to critical conditions and high mortality. Of such blunt trauma-induced injuries, coronary artery dissection, tricuspid valve injury, and pericardial rupture caused by blunt chest trauma are rare, and simultaneous occurrence of the three types of injuries that were successfully repaired has not been reported. In addition, this case indicates the utility of contrast ultrasonography for diagnosis of pericardial rupture caused by blunt chest trauma.

[Mitral Valvuloplasty of Infective Endocarditis During Pregnancy].

This report describes a case in which we treated a patient who developed infective endocarditis in the mitral valve at 28 weeks' gestation. The condition was resolved by performing mitral valvuloplasty 2 days after an emergency cesarean section. Although the patient was in a relatively stable period at 32 weeks' gestation, the mother had an extremely high risk of embolism;thus, emergency surgery was required. We believe that an accurate diagnosis in a timely manner and a valvuloplasty shortly after cesarean section saved the life of the mother and child.

Effect of decellularized tissue powders on a rat model of acute myocardial infarction.

Many research groups are currently investigating new treatment modalities for myocardial infarction. Numerous aspects need to be considered for the clinical application of these therapies, such as low cell integration and engraftment rates of cell injection techniques. Decellularized tissues are considered good materials for promoting regeneration of traumatic tissues. The properties of the decellularized tissues are sustained after processing to powder form. In this study, we examined the use of decellularized tissue powder in a rat model of acute myocardial infarction. The decellularized tissue powders, especially liver powder, promoted cell integration and neovascularization both in vitro and in vivo. Decellularized liver powder induced neovascularization in the infarct area, resulting in the suppression of myocardial necrosis. The results of this study suggest that decellularized liver powder has good potential for application as a blood supply material for the treatment of myocardial infarction.

Decellularized porcine aortic intima-media as a potential cardiovascular biomaterial.

OBJECTIVES: The aim of this research is to investigate the histological and mechanical properties of decellularized aortic intima-media, a promising cardiovascular biomaterial. METHODS: Porcine aortic intima-media was decellularized using two methods: high hydrostatic pressurization (HHP) and sodium dodecyl sulphate (SDS). The histological properties were characterized using haematoxylin and eosin staining and Elastica van Gieson staining. The mechanical properties were evaluated using a tensile strength test. RESULTS: The structure of the HHP-treated samples was unchanged histologically, whereas that of the SDS-treated samples appeared structurally loose. Consequently, with regard to the mechanical properties of SDS-decellularized intima-media, elastic modulus and tensile strength were significantly decreased. CONCLUSIONS: The decellularization method affected the structure and the mechanical properties of the biomaterial. The HHP-treated sample was structurally and mechanically similar to the untreated control. Its mechanical properties were similar to those of human heart valves and the iliac artery and vein. Our results imply that porcine aortic intima-media that is decellularized with HHP is a potential cardiovascular biomaterial.

Stress echocardiographic assessment of mitral valve function repaired using rough-zone trimming.

BACKGROUND: We invented novel mitral valve repair technique; rough-zone trimming procedure (RZT) for anterior mitral valve prolapse. Prolapse site was resected in obtuse triangle shape and sutured edges to creates deep coaptation and improves regurgitation. Though it is simple and reproducible technique, functional mitral stenosis is a risk. Valve function and hemodynamics were investigated using dobutamine stress echocardiography (DSE) in patients after mitral valve repair using RZT. METHODS: Patients underwent RZT for the anterior mitral valve (AML, n = 10), quadrangular resection (QR) of the posterior mitral valve (PML; n = 4), RZT + QR of bileaflet valves (bileaflet; n = 4) and healthy individuals (control; n = 10) and were assessed by DSE (doses up to 20 µg/Kg/min). Echocardiographic data including mitral valve area (MVA), mitral valve mean pressure gradient (MVmeanPG), and systolic pulmonary artery pressure (sPAP) were measured at rest and at peak stress. RESULTS: Rest/stress MVA (cm(2)), MVmeanPG (mmHg) and sPAP (mmHg) were 2.8 ± 0.4 and 3.4 ± 0.3, 3.3 ± 1.1 and 7.4 ± 4.1, and 25.7 ± 4.7and 49.1 ± 4.1, respectively, in the AML group. Dobutamine stress increased all parameters but not to pathological levels. The results were similar to those of the other groups after mitral valve repair, whereas MVA was larger and MVmeanPG was lower in the control than in the AML group. CONCLUSIONS: Valve repair using RZT does not pathologically obstruct the mitral valve, either at baseline or during dobutamine stress, and does not affect valve hemodynamics and reserve.

New parameter of the right gastroepiploic arterial graft using the power spectral analysis device named MemCalc soft.

OBJECTIVES: Transit-time flow measurement (TTFM) parameters such as mean graft flow (MGF, ml/min), pulsatility index (PI) and diastolic filling (DF, %) have been extensively researched for internal mammary arterial or saphenous vein grafts. In our experience of using the right gastroepiploic arterial (GEA) graft for right coronary artery (RCA) grafting, we observed unique GEA graft flow waveforms. We analysed the GEA graft flow waveforms for their effectiveness in determining GEA graft patency by power spectral analysis. METHODS: Forty-five patients underwent off-pump coronary artery bypass using the GEA graft for RCA grafting individually. The means of intraoperative MGF, PI and DF were compared between patent and non-patent grafts, postoperatively. Furthermore, the GEA flow data were output and analysed using power spectral analysis. RESULTS: Forty grafts were 'patent' and five were 'non-patent'. There were no significant differences in the mean TTFM parameters between the patent and non-patent grafts (MGF: 22 vs 8 ml/min, respectively, P = 0.068; PI: 3.5 vs 6.5, respectively, P = 0.155; DF: 63 vs 53%, respectively, P = 0.237). Results of the power spectral analysis presented clear differences; the power spectral density (PSD) of patent grafts presented high peaks at frequency levels of 1, 2 and 3 Hz, and the non-patent graft PSD presented high peaks that were not limited to these frequencies. The PSD had a sensitivity and specificity of 80 and 87.5%, respectively. CONCLUSIONS: Power spectral analysis of the GEA graft flow is useful to distinguish between non-patent and patent grafts intraoperatively. This should be used as a fourth parameter along with MGF, PI and DF.

Impact of novel intraoperative evaluation for mitral valve regurgitation: the retrograde cardio-protective beating test.

PURPOSE: The saline injection test is commonly employed during mitral valvuloplasty. However, discrepancies in regurgitation between the naked eye findings during the saline injection test and the postoperative echocardiographic findings have been noted. Here, we describe the new retrograde cardio-protective beating test (RC-beating test) which allows direct transatrial evaluation of the valve in the fully loaded, beating heart under cross-clamping by means of the retrograde perfusion of warm oxygenated blood into the coronary sinus. METHODS: From January 2006 to June 2012, 63 patients (mean age, 59 ± 15 years) with degenerative mitral valve regurgitation underwent mitral valve repair with application of this novel evaluation. RESULTS: In 20 of the 63 patients (31.8%), minor residual leaks that were not remarkable in the saline injection test were detected during the RC-beating test and were completely corrected. Almost all patients (n = 61, 96.8%) revealed no mitral regurgitation on intraoperative transesophageal echocardiography. The results of the RC-beating test were satisfactory, and discrepancies were not recognized at all between this evaluation and the postoperative echocardiographic findings. The ultrastructure of the mitochondria showed significant myocardial preservation. CONCLUSION: The RC-beating test is a simpler and more accurate evaluation for mitral valve repair than the saline injection test. This novel evaluation enables a safe and more complete mitral valve repair.

Risk factors for a persistent type 2 endoleak after endovascular aneurysm repair.

PURPOSE: To investigate the natural course of type 2 endoleaks (T2Es) and to identify the risk factors associated with a persistent T2E after endovascular aneurysm repair (EVAR). METHODS: The medical records of patients who underwent EVAR for the treatment of an atherosclerotic abdominal aortic aneurysm between October 2006 and December 2011 at our institute were reviewed. T2Es were diagnosed by contrast-enhanced computed tomography within 4 weeks of EVAR, and patients were followed up at 6 and 12 months. In cases where a T2E was detected, the blood vessels responsible for the T2E were identified and statistically analyzed for their association with a persistent T2E. RESULTS: We identified T2Es in 111 of 469 patients within 4 weeks of undergoing EVAR. During the follow-up, 41 patients (36.9 %) showed spontaneous resolution of their T2E. The percentage of patients with a T2E was 75.4, 69.2 and 58.0 % at 6, 12 and 24 months, respectively. T2E caused by defects in multiple vessels and T2E associated with the fourth lumbar artery were identified as risk factors associated with a persistent T2E in the univariate analysis. In the multivariate analysis, T2E caused by multiple vessels was identified as the only independent risk factor for a persistent T2E. CONCLUSIONS: We identified T2E caused by multiple vessel failure as an independent risk factor for persistent T2E.

Herniation of transverse colon into mediastinum after pedicled omental grafting for mediastinitis: report of a case.

We describe a rare complication and the treating experience of it after pedicled omental grafting for mediastinitis. The patient was diagnosed as an acute mediastinitis soon after the total arch replacement was performed. A two-staged strategy to treat postoperative mediastinitis was scheduled, i.e., the setting up of a vacuum-assisted closure system until the improvement of inflammation followed by wound closure with pedicled omental grafting. The treatment for acute mediastinitis was successful and the patient followed a favorable postoperative course. During the follow-up, chest X-ray film suggested the gradual enlargement of mediastinum and CT showed the herniation of transverse colon into mediastinum. Surgical correction for the hernia was scheduled and performed successfully by the laparoscopic procedure to prevent a possible cardiac and pulmonary dysfunction.

Porcine radial artery decellularization by high hydrostatic pressure.

Many types of decellularized tissues have been studied and some have been commercially used in clinics. In this study, small-diameter vascular grafts were made using HHP to decellularize porcine radial arteries. One decellularization method, high hydrostatic pressure (HHP), has been used to prepare the decellularized porcine tissues. Low-temperature treatment was effective in preserving collagen and collagen structures in decellularized porcine carotid arteries. The collagen and elastin structures and mechanical properties of HHP-decellularized radial arteries were similar to those of untreated radial arteries. Xenogeneic transplantation (into rats) was performed using HHP-decellularized radial arteries and an untreated porcine radial artery. Two weeks after transplantation into rat carotid arteries, the HHP-decellularized radial arteries were patent and without thrombosis. In addition, the luminal surface of each decellularized artery was covered by recipient endothelial cells and the arterial medium was fully infiltrated with recipient cells.

Evaluation of gastroepiploic arterial grafts to right coronary artery using transit-time flow measurement.

OBJECTIVES: The objective of this study was to analyse the relationship between the intraoperative transit-time flow measurement (TTFM) parameter values and the postoperative angiographic results of gastroepiploic arterial (GEA) grafts to the right coronary artery (RCA). We investigated whether the intraoperative TTFM parameter values are reliable indicators of early patency in GEA grafts to the RCA. METHODS: Patients undergoing off-pump coronary artery bypass surgery with GEA grafts were included in this study. Eighty-three GEA grafts were individually anastomosed and examined by angiography 1 week after surgery. The quality of each graft was graded using FitzGibbon grading (Study 1) and graft-flow grading (Study 2). RESULTS: Study 1: Seventy-two grafts were determined as Grade A and 11 as Grades B or O. There were no significant differences in the average of mean graft flow (MGF), pulsatility index or diastolic filling percentage between Grade A and Grades B or O grafts. Study 2: Sixty-two grafts were graded as good-graft dominant, 16 as bidirectional and 5 as occlusion including string. The average of the MGF, pulsatility index and diastolic filling percentage in the grafts graded as bidirectional and occlusion including string were not significantly different from those of grafts graded as good-graft dominant. CONCLUSIONS: Previously reported cut-off values for intraoperative TTFM parameters could not be adapted for the early patency of GEA grafts to the RCA. However, the smoothness of the graft-flow curve may be a reliable predictor of postoperative graft patency.

[Intraoperative evaluation for residual mitral valve regurgitation; usefulness of the retrograde cardioprotective beating test].

Intraoperative evaluation is important for successful mitral valve plasty (MVP). We performed a saline injection test and a retrograde cardioprotective beating test (RC-beating test) for intraoperative evaluation. The concept of the RC- beating test is evaluation of residual mitral valve regurgitation( MR) under cardiac beating. A 66-year-old man with severe MR underwent MVP. The P3 chorda was ruptured and we performed quadrangular resection. The saline injection test showed trivial regurgitation. We then performed the RC-beating test and it revealed severe leakage from the posterior commissure(PC). Since the PC had a sclerotic change, another quadrangular resection was performed. Moreover,as the anterior leaflet( A3) was slightly elongated, the region was resected in an obtuse-angled triangle shape and repaired by suturing the edges. The final RC-beating test showed no residual leakage. The RC-beating test is useful for detecting residual mitral valve leakage.

Acute dilatation of the ascending aorta and aortic valve regurgitation in Loeys-Dietz syndrome.

Loeys-Dietz syndrome (LDS) is a recently recognized connective tissue disorder caused by mutations of the transforming growth factor (TGF)-ß receptors. It is an autosomal dominant syndrome characterized by the triad of arterial tortuosity and aneurysms, hypertelorism, and bifid uvula or cleft palate. We treated an 18-year-old woman with a 100-mm-diameter aortic root aneurysm and severe aortic valve regurgitation. She underwent urgent aortic root replacement and bioprosthetic valve implantation. LDS was diagnosed by postoperative genetic screening results. Histopathologic examination of the aortic wall showed diffuse degeneration and elastin fragmentation in the media.

Right axillary arterial perfusion for descending thoracic or thoracoabdominal aortic aneurysm repair with open proximal anastomosis through left thoracotomy.

BACKGROUND: We examined the effectiveness of right axillary arterial perfusion through an interposed Dacron graft in the prevention of cerebral embolism or complications related to ascending aortic cannulation in open proximal anastomosis technique of descending thoracic aortic aneurysm (TAA) or thoracoabdominal aortic aneurysm (TAAA) repair under deep hypothermic circulatory arrest through left thoracotomy. METHODS: Between May 2000 and August 2012, 44 patients underwent TAA or TAAA repair using open proximal technique under DHCA. These patients were divided into two groups for evaluation of the effectiveness of right axillary arterial perfusion. Group A included patients who underwent TAA or TAAA repair with ascending aortic cannulation (n=15). Group B was composed of patients who had TAA or TAAA repair with right axillary arterial perfusion through the interposed Dacron graft (n=29). RESULTS: Mortality in this series was 4.5% (2 of 44 patients; 1 in each group); wherein, the causes were sepsis due to graft infection and aortic dissection (Stanford type A). The incidence rates of cerebral embolism were 27 % (4 of 15 patients in group A) and 3.4% (1 of 29 patients in group B) (p=0.0392, Fisher's exact test). The rates of complications in relation to the aortic cannulation site (dissection or bleeding) were 13% (2 of 15 patients in group A) and 0% (0 of 25 patients in group B). CONCLUSIONS: Right axillary perfusion facilitates easy evacuation of air and allows prompt recommencement of upper body circulation. Consequently, it minimizes the risk of cerebral embolism or complications in relation to aortic cannulation through left thoracotomy.

Fabrication of a heparin-PVA complex hydrogel for application as a vascular access.

A high hydrostatic pressure method, which can apply over 600 MPa pressure was employed for preparing a hydrogel of poly(vinyl alcohol) (PVA) loaded with heparin. The aim of this study was to fabricate a heparin-PVA hydrogel conduit and evaluate its potential for vascular access. Heparin-PVA complex hydrogel showed suppressed heparin release and prevented clot formation, depending on the molecular weight of the PVA. Strength of the hydrogel conduit was increased by embedding a Dacron mesh between two PVA layers. The tubular heparin-PVA complex hydrogel displayed a burst pressure of 750 mmHg. The tubular heparin-PVA complex hydrogel did not show any occlusion or burst for 2 weeks after implantation, implying that this heparin-PVA complex hydrogel shows high potential for use as a vascular access. This is the first report on the preparation of a multilayered PVA hydrogel with heparin embedded on one side only. The proposed approach could be expanded to the fabrication of various biomaterials for specific purposes.

Mitral valve plasty for idiopathic rupture of mitral valve posterior chordae in infants.

INTRODUCTION: Idiopathic mitral valve chordal rupture is rare among infants. Once it has occurred, acute heart failure progresses, and emergency surgical repair is necessary in most cases. Our surgical experience with idiopathic mitral valve chordal rupture is reported. PATIENTS AND METHODS: From September 2008 to May 2012, four infants (3 males, 1 female; median age 5.5 months) underwent mitral valve plasty for severe mitral valve regurgitation due to prolapse of posterior mitral valve leaflet. Patient history, surgical procedure, operation time, mortality, postoperative echocardiography data (mitral valve regurgitation grade: 0-trivial, mild, moderate, severe, transmitral flow: TMF) and pathology were examined. RESULTS: Three cases required emergency surgery; 1 case, elective surgery. Intraoperative findings showed chordal rupture of the P2 segment in 3 cases and P1 + P3 segments in 1 case. Quadrangular resection with annular plication was performed for 1 case. Quadrangular resection with annular plication and the Kay procedure were performed for 3 cases. Mitral valve regurgitation improved from severe to trivial-mild in all cases. Pathological examination showed a myxomatous degenerative change in the mitral valve. CONCLUSION: Mitral valve plasty was performed for idiopathic mitral valve chordal rupture in infants. The surgical procedures were the same as for adult cases and achieved satisfactory results.