Yoshimori Araki

Outcome of Pericardiectomy for Constrictive Pericarditis in Japan: A Nationwide Outcome Study

BACKGROUND We evaluated the current results and the predictors of in-hospital complications for a pericardiectomy procedure for constrictive pericarditis in Japan. METHODS A total of 346 patients who underwent isolated pericardiectomy for constrictive pericarditis nationwide between 2008 and 2012 were identified from the Japan Adult Cardiovascular Surgery Database. RESULTS The patients were a mean age of 65.7 ± 11.7 years. The operative approach was through a median sternotomy in 90% of the patients. Cardiopulmonary bypass was used in 28.9%. The operative mortality rate was 10.0%, and the composite operative mortality or major morbidity (stroke, reoperation for bleeding, need for mechanical ventilation for more than 24 hours postoperatively due to respiratory failure, renal failure with newly required dialysis or mediastinitis) was 15.0%. Logistic regression analysis revealed that the predictive factors for composite operative mortality or major morbidity were preoperative chronic lung disease (odds ratio [OR], 4.75; p < 0.001), New York Heart Association functional class IV (OR, 3.85; p < 0.001), previous cardiac operation (OR, 2.68; p = .006), preoperative renal failure (OR, 2.62; p = .014), and cardiopulmonary bypass during the operation (OR, 2.46; p = .015). The frequency of using cardiopulmonary bypass was 2.9% in the patients treated through a left thoracotomy approach vs 31.8% in the patients treated through a median sternotomy approach (p < 0.0001). CONCLUSIONS Pericardiectomy is associated with high morbidity and mortality rates. Careful consideration should be given to these risk factors in the process of patient selection and perioperative management.

Hybrid versus open repair of aortic arch aneurysms: comparison of postoperative and mid-term outcomes with a propensity score-matching analysis

OBJECTIVES Operative strategies for repairing aortic arch aneurysms should be re-evaluated following recent technical advances. METHODS Of 364 patients who underwent aortic arch repair between 2002 and 2014, 58 were high-risk subjects who received isolated hybrid arch repair (HAR) via median sternotomy (type I n = 32, type II n = 1 and type III n = 25). During this period, excluding patients with type A dissection or extensive aneurysms, 124 patients received isolated open arch repair via median sternotomy. The patients in the HAR and open arch repair groups were compared. A propensity score-matching analysis was applied to adjust for baseline risk factors. RESULTS The patients in the HAR group were older (77 years ± 6 vs 69 ± 9, P < 0.0001), exhibited a greater rate of malignancy (21 vs 4.8%, P = 0.0022) and had higher logistic EuroSCORE values (31 ± 18 vs 20 ± 15, P < 0.0001) than those in the open arch repair group. Following propensity score matching creating 38 matched pairs, the differences in preoperative risk diminished. Operative complications, including the mortality rate (2.6 vs 0%), were similar between the groups. Apart from the lower rates of cardiopulmonary bypass (CPB) and circulatory arrest, there was no apparent superiority of HAR with respect to patient recovery. The mean follow-up duration was 52.5 months, during which the rate of freedom from aortic events in the HAR and open arch repair groups was 79 and 99% at 24 months, respectively (P < 0.0001). CONCLUSIONS HAR achieves equivalent short-term results to standard open arch repair, with a decreased need for CPB. However, considering the inferior mid-term outcomes of this procedure, its indications should be limited to high-risk patients.

Spinal cord protection during a thoracoabdominal aortic repair for a chronic type B aortic dissection using the aortic tailoring strategy

This study evaluated the clinical advantage of a novel technique to reconstruct a true lumen with aortic wall tailoring for aortic repair (aortic tailoring) or the reimplantation of intercostal arteries (vascular tube) in a chronic type B aortic dissection. Thirty-three consecutive extended thoracoabdominal aortic repairs have been performed for chronic type B dissection since 2000. The novel strategy was applied in 17 cases since 2004 including eight cases of aortic repair (group A) and nine cases of a vascular tube (group B). The other 16 cases were graft interposition in five and no reimplantation in 11 for group C. There were no surgical deaths in either group A or B, and only one late death in group C. No patients sustained transient or permanent paraplegia in group A and B, while three cases of paraplegia occurred in group C (18.8%). All of the intercostal arteries were well preserved in group A and an average of 9.8 intercostal arteries for nine patients were reimplantated in group B. The present technique can optimally preserve the intercostal arteries maximally and showed an excellent surgical mortality and morbidity, especially with regard to the protection of the spinal cord.

Therapeutic potential of bone marrow-derived mesenchymal stem cells in formed aortic aneurysms of a mouse model

OBJECTIVES An aortic aneurysm (AA) is caused by atherosclerosis with chronic inflammation. Mesenchymal stem cells (MSCs) have potential anti-inflammatory properties. In this study, we examined whether an already-formed AA can be treated by intravenous injection of bone marrow-derived (BM)-MSCs in a mouse model. METHODS AA was induced in apolipoprotein E-deficient mice by angiotensin II-infusion for 28 days through sub-cutaneous osmotic mini-pumps. After that, 1 × 10(6) BM-MSCs (in 0.2 ml saline) or 0.2 ml saline as a control was injected via the tail vein. Mice were sacrificed at 2 (saline group n = 10, BM-MSC group n = 10), 4 (saline group n = 6, BM-MSC group n = 7) or 8 weeks (saline group n = 5, BM-MSC group n = 6) after injection. The aortic tissues of each group were dissected. Aortic diameter, elastin content, matrix metalloproteinase (MMP)-2 and -9 enzymatic activity and cytokine concentrations were measured, as was macrophage infiltration, which was also evaluated histologically. RESULTS The incidence of AA in the BM-MSC group was reduced at 2 weeks (BM-MSC 40% vs saline 100%, P < 0.05), and aortic diameter was reduced at 2 and 4 weeks (2 weeks: 1.40 vs 2.29 mm, P < 0.001; 4 weeks: 1.73 vs 2.32 mm, P < 0.05). The enzymatic activities of MMP-2 and -9 were reduced in the BM-MSC group at 2 weeks (active-MMP-2: 0.28 vs 0.45 unit/ml, P < 0.05; active-MMP-9: 0.16 vs 0.34 unit/ml, P < 0.05). Inflammatory cytokines were down-regulated in the BM-MSC group (interleukin-6: 2 weeks: 1475.6 vs 3399.5 pg/ml, P < 0.05; 4 weeks: 2184.7 vs 3712.8 pg/ml, P < 0.05 and monocyte chemotactic protein-1: 2 weeks: 208.0 vs 352.7 pg/ml, P < 0.05) and insulin-like growth factor (IGF)-1 and tissue inhibitor of metalloproteinase (TIMP)-2 were up-regulated in the BM-MSC group at 2 weeks (IGF-1: 4.7 vs 2.0 ng/ml, P < 0.05; TIMP-2: 9.5 vs 4.0 ng/ml, P < 0.001). BM-MSC injection inhibited infiltration of M1 macrophages and preserved the construction of elastin. CONCLUSIONS Our results suggest that BM-MSCs might be an effective treatment for AA. Further investigation is necessary to optimize the injected dosage and the frequency of BM-MSCs to prevent a transient effect.

A bioresorbable osteosynthesis device can induce an earlier sternal fusion after median sternotomy

OBJECTIVES We examined the impact of the bioresorbable osteosynthesis sternal pin (Super Fixsorb 30) on sternal healing after median sternotomy. METHODS Sixty-three patients who underwent aortic surgery through median sternotomy between January 2006 and March 2009 were analysed. Sternal pins were utilized in 36 patients in addition to the standard closure of the sternum with Ethibond sutures (Group A), and 27 patients received no pins with the standard Ethibond sternal closure (Group B). The occurrence of transverse sternal dehiscence, anterior-posterior displacement and complete fusion of the sternum were evaluated by a computed tomography scan. The cross-sectional cortical bone density area (CBDA) of the sternum was examined to evaluate the osteoconductivity of the sternal pin over a 12-month period. RESULTS There was no sternal displacement (0%) observed in Group A at discharge. Meanwhile, five displacements (18.5%) were observed in Group B (P = 0.007). The complete sternal fusion rates at 12 months postoperatively were 100% in Group A, and 21.6% in Group B (P < 0.001). A significant increase in the CBDA was observed in Group A (P < 0.001; between CBDA at discharge and 12 months postoperatively). CONCLUSIONS The Super Fixsorb 30 sternal pin reduced an anterior-posterior sternal displacement and facilitated an earlier sternal fusion. The pin may have the potential to promote osteogenesis.

Predictors of early graft failure after coronary artery bypass grafting for chronic total occlusion

OBJECTIVES Little is known regarding the transit-time flow measurement (TTFM) variables in grafts anastomosed to chronically totally occluded vessels (CTOs). We aimed to establish the TTFM cut-off values for detecting graft failure in bypass grafts anastomosed to chronically totally occluded arteries and clarify the relationship between early graft failure and the grade of collateral circulation/regional wall motion of the CTO territory. METHODS Among 491 patients who underwent isolated coronary artery bypass grafting (CABG) from 2009 to 2015, 196 cases with CTOs underwent postoperative coronary angiography within 1 month after CABG. Two hundred and forty-one CTOs in all patients were examined. Thirty-two CTOs (13%) were not bypassed and 214 conduits were anastomosed to CTOs and underwent intraoperative TTFM. Arterial conduits and saphenous vein grafts (SVGs) were used in 102 and 112 cases, respectively. Among the arterial conduit procedures that were performed, 78 involved the left internal thoracic artery (LITA), 10 involved the right internal thoracic artery (RITA) and 14 involved the right gastroepiploic artery (rGEA). Any graft showing Fitzgibbon type B or O lesions on angiography was considered to be a failing graft. RESULTS The insufficiency rates for LITA, RITA, rGEA and SVG procedures were 5.1, 10, 14.3 and 7.1%, respectively. The TTFM variables recorded in failing grafts had a significantly lower mean flow (Qmean) and higher pulsatility index (PI) compared with patent grafts. Furthermore, akinetic or dyskinetic wall motion in the territory of bypassed CTOs was observed at a significantly higher rate in failing grafts. A multivariable regression analysis and receiver operating characteristic analysis revealed good predictors of early graft failure as follows: a Qmean value of < 11.5 ml/min for arterial conduits, a PI value of >5.85 and akinetic/dyskinetic wall motion in the CTO territory for SVGs. The Rentrop collateral grade was not associated with early graft failure. CONCLUSIONS The Qmean value and PI value by the TTFM are useful to detect early graft failure in conduits anastomosed to CTOs. The collateral grade is not associated with graft failure; however, bypass grafting to CTOs with akinetic/dyskinetic wall motion should be carefully considered.

Mitral valve motion after performing an edge-to-edge repair in an isolated swine heart

OBJECTIVES Mitral valve motion after performing an edge-to-edge repair is a major concern, but it has not yet been observed directly. Mitral valve motion was assessed by using a high-speed digital video camera and microsonometric analysis in an isolated swine heart, and any changes in the mitral valve area or the development of mitral stenosis symptoms were evaluated. METHODS A temporary edge-to-edge repair model was created. The mitral valve motion was assessed by using a high-speed digital video camera, and the motion of the mitral annulus was measured by means of sonomicrometric analysis with or without performing edge-to-edge repair (n = 5). The left ventricular volumetric measurements were also measured with a conductance catheter. One cardiac cycle was divided into 4 phases: the mitral valve open phase, the isovolumic contraction phase, the aortic valve open phase, and the isovolumic relaxation phase. RESULTS The mitral valve was divided into 2 orifices by using the edge-to-edge technique, and the mitral valve area decreased by approximately 30%. The ratio of mitral valve open phase significantly decreased (31.9% +/- 3.4% vs 41.4% +/- 3.7%, P = .04). There were no significant differences in the diameter and the changes of anteroposterior dimensions of the mitral annulus. The stroke volume and the peak positive and negative dp/dt values showed no obvious change, but dv/dt values increased slightly without significance after removing the edge-to-edge suture (118 +/- 25 vs 130 +/- 17 mL/s, P = .14). CONCLUSIONS The mitral valve area decreased slightly; however, edge-to-edge repair did not create symptomatic mitral stenosis and showed no adverse affects on cardiac function.

A Needle Stick Technique for Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy

We developed a needle stick technique for treating hypertrophic obstructive cardiomyopathy. Three 21-gauge needles are inserted into the interventricular septum just below the aortic valve annulus beyond the far side of the septal bulge. The right and left needles are both side margins, and the center needle is a guide for the thickness. Each needle plays a role as a mark of resection for the width, length, and thickness. The needles also stabilize the ventricular septum and provide good exposure of the entire septal hypertrophy. This technique is helpful to safely achieve sufficient septal myectomy of a constant thickness.

Long-term results of the maze procedure in patients with mechanical valve

BackgroundThe advantage of the Maze procedure concomitant with the mechanical valve implantation is unclear. This study evaluated the long-term results of mechanical valve implantation either alone or concomitant with the Maze procedure.MethodsBetween 1990 and 2005, 208 patients underwent mitral valve replacement with a mechanical valve. Maze procedure was concomitantly performed in 77 patients, and 54 of these had restored sinus rhythm (Maze group). The other 131 patients did not perform the Maze procedure (non-Maze group). Survival and late outcomes were studied retrospectively with univariate analysis (log-rank test), and a case-matched study by propensity score was performed. The late New York Heart Association (NYHA) functional status obtained by questionnaire and the cardiac function observed by echocardiography were studied for comparison of the two groups.ResultsSurvival and late outcomes, except for bleeding, were not significantly different between the groups, and this was also true of the case-matched study. In the NYHA functional status, the Maze group had more class I patients, while the non- Maze group has more class II patients. The left ventricular ejection fraction, left atrial enlargement, and tricuspid regurgitation were not significant factors affecting the differences between class I and II patients.ConclusionsThe Maze procedure is considered to be worth for patients who need life-long anticoagulation for the mechanical valve because it improves the NYHA functional status.

Surgical treatment of ruptured aneurysm of the left sinus of Valsalva caused by Takayasu arteritis.

Takayasu arteritis is a chronic large-vessel vasculitis that is more frequently observed in young women. We report the case of a 29-year-old woman who required an operation for an aneurysm of the left sinus of Valsalva that ruptured into the left ventricle, for aortic regurgitation, and for left main coronary trunk stenosis. The patient had not been previously diagnosed with Takayasu arteritis.