A novel atrial volume reduction technique to enhance the Cox maze procedure: Initial results

ObjectiveLarge left atrial diameter is reported to be a predictor for recurrent atrial fibrillation after the Cox maze procedure, and left atrial diameter by itself influences the chance of sinus rhythm recovery, as well as maintenance of sinus rhythm. However, additional cut-and-sew procedures to decrease left atrial diameter extend operative time and can cause bleeding. Thus we developed a no-bleeding, faster, and therefore less invasive left atrial volume reduction technique to enhance the Cox maze procedure.MethodsThe modified Cox maze III procedure with cryoablation or the left atrial maze procedure in association with mitral valve surgery was performed in 80 patients with atrial fibrillation and enlarged left atria (≥60 mm). Among them, 44 patients had the concomitant volume reduction technique (VR group); continuous horizontal mattress sutures for left atrial plication were placed on the left atrial wall along the pulmonary vein isolation line. Cryoablation was applied to the suture line so that the plicated left atrium is anatomically and electrically isolated. Another 36 patients did not have the volume reduction technique (control group).ResultsThe VR group had preoperative left atrial diameters similar to those of the control group (67.1 ± 7.8 vs 64.5 ± 6.7 mm) and a longer preoperative duration of atrial fibrillation (14.1 ± 5.4 vs 9.5 ± 5.1 years, P < .05) but had smaller postoperative left atrial diameters (47.6 ± 6.3 vs 62.1 ± 7.9 mm, P < .01). There were no differences in mean crossclamp/bypass time and chest tube drainage for 12 hours between the groups. Twelve months after surgical intervention, the sinus rhythm recovery rate of the VR group was better than that of the control group (90% vs 69%, P < .05).ConclusionsEven in patients with long-standing atrial fibrillation and an enlarged left atrium, maze procedures concomitant with the novel left atrial volume reduction technique improved the sinus rhythm recovery rate without increasing complications. Although further study with a larger number of patients and a longer follow-up period is needed, this safe and thus far potent technique that catheter-based ablation cannot copy might extend indication of the Cox maze procedure for patients with tough atrial fibrillation

Chronic partial unloading restores β-adrenergic responsiveness and reverses receptor downregulation in failing rat hearts

ObjectivesMechanical unloading with a left ventricular assist device promotes “reverse remodeling,” including restoration of β-adrenergic receptor signaling and function. We compared the effects of partial unloading and complete unloading on β-adrenergic responsiveness and gene expressions in failing rat hearts by use of heterotopic heart–lung or heart transplantation models.MethodsFour weeks after ligation of the left anterior descending artery in Lewis rats, rats with heart failure were divided into 3 groups: infarcted hearts and lungs transplanted into the recipient rats (heart failure–partial unloading, n = 8); infarcted hearts transplanted into the recipient rats (heart failure–complete unloading, n = 7); infarcted (heart failure, n = 8) hearts without transplantation. Normal rats (n = 7) were used as controls. Papillary muscle function and gene expressions were studied at 2 or 4 weeks after transplantation.ResultsIn 2-week models, baseline developed tension of papillary muscles significantly increased in heart failure–partial unloading and heart failure–complete unloading compared with heart failure (0.15 ± 0.07 and 0.12 ± 0.05 g/mm2 vs 0.02 ± 0.01 g/mm2, P < .05). However, in 4-week models, they decreased to 0.11 ± 0.03 and 0.10 ± 0.03 g/mm2. In 4-week but not in 2-week models, the increase from baseline in baseline developed tension produced by β-adrenergic stimulation (isoproterenol, 10−8 and 10−7 mol/L) was significantly increased in heart failure–partial unloading compared with heart failure–complete unloading and heart failure (P < .05). The mRNA expressions of brain natriuretic peptide and β1- and β2-adrenergic receptors were normalized in both 2- and 4-week models of heart failure–partial unloading.ConclusionsChronic partial unloading but not complete unloading improved β-adrenergic responsiveness and normalized brain natriuretic peptide and β1- and β2-adrenergic receptor mRNA expressions in the failing rat hearts

Alternative redo sternotomy in a patient with tracheostoma and patent grafts.

We describe a redo mitral valve replacement operation in a 71-year-old man with a tracheostoma and patent bypass grafts to the coronary arteries. Preoperative investigations revealed that the patent right internal thoracic artery graft ran directly under the sternum just anterior to the ascending aorta, and a saphenous vein graft was adhering to a surgical wire. To prevent injury to the patent grafts and cardiac structures, and to avoid communication with the tracheostoma, the redo procedure was performed via an anterior minithoracotomy combined with a low T-shaped partial sternotomy. The reoperation was successfully completed without any complications

Percutaneous coronary intervention using new-generation drug-eluting stents versus coronary arterial bypass grafting in stable patients with multi-vessel coronary artery disease: From the CREDO-Kyoto PCI/CABG registry Cohort-3

AIMS: There is a scarcity of studies comparing percutaneous coronary intervention (PCI) using new-generation drug-eluting stents (DES) with coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease. METHODS AND RESULTS: The CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who underwent first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. The current study population consisted of 2464 patients who underwent multi-vessel coronary revascularization including revascularization of left anterior descending coronary artery (LAD) either with PCI using new-generation DES (N = 1565), or with CABG (N = 899). Patients in the PCI group were older and more often had severe frailty, but had less complex coronary anatomy, and less complete revascularization than those in the CABG group. Cumulative 5-year incidence of a composite of all-cause death, myocardial infarction or stroke was not significantly different between the 2 groups (25.0% versus 21.5%, P = 0.15). However, after adjusting confounders, the excess risk of PCI relative to CABG turned to be significant for the composite endpoint (HR 1.27, 95%CI 1.04-1.55, P = 0.02). PCI as compared with CABG was associated with comparable adjusted risk for all-cause death (HR 1.22, 95%CI 0.96-1.55, P = 0.11), and stroke (HR 1.17, 95%CI 0.79-1.73, P = 0.44), but with excess adjusted risk for myocardial infarction (HR 1.58, 95%CI 1.05-2.39, P = 0.03), and any coronary revascularization (HR 2.66, 95%CI 2.06-3.43, P<0.0001). CONCLUSIONS: In this observational study, PCI with new-generation DES as compared with CABG was associated with excess long-term risk for major cardiovascular events in patients who underwent multi-vessel coronary revascularization including LAD

エンキセイ センイガ サイボウ ゾウショク インシ オヨビ カン ガサイボウ ゾウショク インシ ノ ドウジ ジョホウ ニ ヨル ケッカン ケイセイ ゾウキョウ コウカ ニ カンスル ケンキュウ

京都大学0048新制・課程博士博士(医学)甲第11413号医博第2836号新制||医||890(附属図書館)23056UT51-2005-D163京都大学大学院医学研究科外科系専攻(主査)教授 中尾 一和, 教授 北 徹, 教授 前川 平学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA