Hirokuni Arai

Thoracic and cardiovascular surgery in Japan during 2012

The Japanese Association for Thoracic Surgery has conducted annual surveys of thoracic surgery throughout Japan since 1987 to determine the statistics regarding the number of procedures according to operative category. Here, we have summarized the results from our annual survey of thoracic surgery performed during 2012. The incidence of hospital mortality was added to the survey to determine the nationwide status, which has contributed to the Japanese surgeons to understand the present status of thoracic surgery in Japan and to make progress to improve operative results by comparing their work with those of others. The Association was able to gain a better understanding of the present problems as well as future prospects, which has been reflected to its activity including education of its members. Thirty-day mortality (so-called ‘‘operative mortality) is defined as death within 30 days of operation regardless of the patient’s geographic location and even though the patient had been discharged from the hospital. Hospital mortality is defined as death within any time interval after an operation if the patient had not been discharged from the hospital. Hospital-to-hospital transfer is not considered discharge: transfer to a nursing home or a rehabilitation unit is considered hospital discharge unless the patient subsequently dies of complications of the operation. The definitions of the Ad Hoc Liaison Committee for Standardizing Definitions of Prosthetic Heart Valve Morbidity of the Society of Thoracic Surgeons and Annual report by The Japanese Association for Thoracic Surgery: Committee for Scientific Affair

Erratum to: Thoracic and cardiovascular surgery in Japan during 2012: Annual report by The Japanese Association for Thoracic Surgery.

Annual report by The Japanese Association for Thoracic Surgery: Committee for Scientific Affair Munetaka Masuda, Hiroyuki Kuwano and Meinoshin Okumura have contributed equally.

White Matter Abnormalities as a Risk Factor for Postoperative Delirium Revealed by Diffusion Tensor Imaging

OBJECTIVE Delirium is a common and critical clinical syndrome in older persons. The authors examined whether any abnormalities in the white matter (WM) assessed by diffusion tensor imaging (DTI) predisposes patients to develop delirium after cardiac surgery and also analyzed other risk factors for delirium. METHOD In 116 consecutive patients who underwent scheduled cardiac operations, fractional anisotropy (FA) values obtained by DTI before the surgery and pre-, peri-, and postoperative factors were evaluated. The postoperative delirium was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for delirium. RESULTS Delirium developed in 19 of 116 patients (16.4%). Eighteen of the patients with delirium (94.7%) were older than 60 years. A multivariate logistic regression analysis showed that advanced age and poor performance on a semantic fluency task (the Word Fluency test animal) were important predictive indicators of the delirium. In addition, a voxel-by-voxel analysis using the Statistical Parametrical Mapping 2 revealed that the FA values of the patients with postoperative delirium were significantly lower than those of the nondelirium patients in the bilaterally widespread deep WMs and bilateral thalamus, whereas the analysis treating age as a nuisance variable indicated a significant change in only four clusters of the brain areas, e.g., the left frontal lobe WM, and left thalamus, when compared with the nondelirium group. CONCLUSION The abnormalities in the deep WMs and thalamus that were mainly accelerated by aging may account for the vulnerability to postoperative delirium, and the semantic word fluency could be a useful predictive indicator of delirium.

Pathophysiological roles of nuclear factor kappaB (NF-kB) in pulmonary arterial hypertension: effects of synthetic selective NF-kB inhibitor IMD-0354

AIMS Proliferation of pulmonary arterial smooth muscle cells (PASMCs) is one histological sign of pulmonary arterial hypertension (PAH). We hypothesized that a signalling cascade from fibroblast growth factor 2 (FGF₂) to plasminogen activator inhibitor 1 (PAI-1) and monocyte chemotactic protein-1 (MCP-1) via nuclear transcription factor nuclear factor kappaB (NF-kB) play a critical role in progression of PAH, and tested this hypothesis both in vivo and in vitro using a synthetic selective NF-kB inhibitor, N-(3,5-Bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide (IMD-0354). METHODS AND RESULTS Monocrotaline (MCT) was injected into 75 Sprague-Dawley rats. Starting at day 14 after MCT injection, we administered IMD-0354 (MCT + IMD group) or vehicle (MCT group) daily. At day 32, 65% of the MCT + IMD group were alive compared with 0% of the MCT group. IMD-0354 prevented increase of right ventricular pressure, and suppressed proliferation and induced apoptosis of PASMCs. mRNA transcript levels of FGF₂, PAI-1, and tissue plasminogen activator (t-PA) were lower in MCT + IMD compared with MCT. In in vitro experiments, IMD-0354 inhibited p65 translocation to the nucleus promoted by FGF₂ in PASMCs. Furthermore, the time courses of extracellular signal-regulated kinase (Erk) 1/2, MCP-1, and PAI-1 stimulated with FGF₂ were each markedly shortened by IMD-0354. CONCLUSIONS We speculate that the positive-feedback loop (Erk1/2-NF-kB-MCP-1-Erk1/2) is associated with progression of PAH by causing FGF₂-induced inflammation in MCT rats. IMD-0354 has potential as a new therapeutic tool for PAH.

New Surgical Procedure for Ischemic/Functional Mitral Regurgitation: Mitral Complex Remodeling

Although numerous surgical techniques have been developed for ischemic/functional mitral regurgitation, none has clearly improved patient outcome. We report the clinical application of a new mitral complex remodeling procedure for ischemic/functional mitral regurgitation that allows comprehensive remodeling of the entire mitral complex. The mitral complex remodeling procedure consists of three major concepts: division and reconstruction of secondary chords, undersized annuloplasty, and bilateral papillary muscle relocation.

Cytosolic phospholipase A2 inhibition attenuates ischemia-reperfusion injury in an isolated rat lung model.

Background. Arachidonic acid metabolites and platelet-activating factor (PAF) are potentially involved in ischemia-reperfusion (IR) lung injury. A key enzyme regulating their metabolism is cytosolic phospholipase A2 (cPLA2). Arachidonyl trifluoromethyl ketone (AACOCF3) is reported to be a potent cPLA2 inhibitor. In the present study, we hypothesized that pharmacological inhibition of cPLA2 might ameliorate IR lung injury. Methods. To test the hypothesis, we examined the effects of AACOCF3 in an isolated rat lung model. Three groups were defined (n=6, each): in the vehicle group, lungs were perfused for 2 hours without an ischemic period. In the ischemic groups, 20 mg/kg of AACOCF3 (AACOCF3 group) or saline (control group) was i.v. administered 15 min before lung harvest. Lungs were flushed with LPD solution, cold-stored 18 hours, and reperfused for 2 hours. Results. IR increased cPLA2 activity mainly via alveolar macrophages, sPLA2 activity, thromboxane and leukotriene formation, and the expression of PAF receptor, whereas AACOCF3 treatment significantly reduced all of these. Compared to the vehicle group, the wet-to-dry ratio, proteins in BAL, and MPO activity increased significantly by twofold, fourfold, and threefold, respectively. Furthermore, the PO2 dropped from 615.7±31.2 to 452.1±30.9 mmHg at the end of reperfusion (P<0.001). AACOCF3 treatment maintained the PO2 at a level similar to the vehicle group throughout reperfusion and reduced significantly the alveolar-capillary leakage, edema formation, and neutrophil extravasation. Conclusion. Pharmacological inhibition of the cPLA2 cascade decreases bioactive lipid formation and attenuates IR-induced lung injury.

Double-patch technique for postinfarction ventricular septal perforation

A modified infarct-exclusion technique for postinfarction ventricular septal perforation is presented. The perforation is closed directly by a small patch next to the conventional patch, and biological glue is applied between the patches to induce stable polymerization. The patch stuck to the infarcted septum, and no residual shunt was observed in any patient because the wide adhesion prevents excessive pressure on the suture line. Seven of 9 patients in whom this method was used had good results. This technique appears suited for repair of ventricular septal perforations, especially those with extensive fresh infarction.

External Shunt for Off-Pump Coronary Artery Bypass Grafting: Distal Coronary Perfusion Catheter

We invented a simple external shunt catheter for off-pump coronary artery bypass grafting. This catheter maintains coronary perfusion from femoral artery, prevents ischemia, reduces back-bleeding, and acts as a suture guide by preventing accidental missuturing of the posterior coronary wall. The insertion and withdraw technique is easier than intraluminal shunt. This catheter would be a useful tool for myocardial protection during off-pump revascularization.

Temporary and permanent biventricular pacing via left ventricular epicardial leads implanted during primary cardiac surgery

OBJECTIVES Biventricular pacing (BVP) is a new strategy for treating patients with severe congestive heart failure (CHF) and intraventricular conduction delay, but its full potential and technicalities of BVP require further evaluation. We evaluated BVP benefits in 4 patients in whom we implanted a left ventricular lead during primary cardiac surgery. METHODS Four CHF patients treated surgically between October 2000 and August 2001 underwent, at primary surgery, the implantation of leads in the right atrium, right ventricle, and left ventricle (LV) for postsurgical BVP. All patients had severe LV dysfunction and dilatation with intraventricular conduction delay. Surgeries involved CABG alone (n = 1), CABG + Dors operation (n = 2), and tricuspid valve replacement + Maze procedure (n = 1). BVP was begun immediately after surgery in all 4 patients. Hemodynamic variables with BVP were compared to those without BVP for each patient, and the utility and technical aspects of implantation were evaluated. RESULTS BVP increased mean systemic blood pressure by 11% and mean LV stroke work index by 19% in the acute postsurgery period, and reduced mitral regurgitation. Two of the patients were implanted with a generator for permanent BVP, one at 1 month and the other at 6 months after surgery. The threshold of the LV epicardial lead of these 2 patients was below 2 V during follow-up, and BVP was successful. CONCLUSIONS Temporary BVP during the short-term after cardiac surgery improved cardiac function and decreased mitral regurgitation in all 4 of our patients. Epicardial lead implantation may thus be a useful option during surgical treatment of patients with CHF and intraventricular conduction delay if long-term permanent BVP is indicated.

Development of a Disposable Maglev Centrifugal Blood Pump Intended for One-Month Support in Bridge-to-Bridge Applications: In Vitro and Initial In Vivo Evaluation

MedTech Dispo, a disposable maglev centrifugal blood pump with two degrees of freedom magnetic suspension and radial magnetic coupling rotation, has been developed for 1-month extracorporeal circulatory support. As the first stage of a two-stage in vivo evaluation, 2-week evaluation of a prototype MedTech Dispo was conducted. In in vitro study, the pump could produce 5 L/min against 800 mm Hg and the normalized index of hemolysis was 0.0054 +/- 0.0008 g/100 L. In in vivo study, the pump, with its blood-contacting surface coated with biocompatible 2-methacryloyloxyethyl phosphorylcholine polymer, was implanted in seven calves in left heart bypass. Pump performance was stable with a mean flow of 4.49 +/- 0.38 L/min at a mean speed of 2072.1 +/- 64.5 rpm. The maglev control revealed its stability in rotor position during normal activity by the calves. During 2 weeks of operation in two calves which survived the intended study period, no thrombus formation was seen inside the pump and levels of plasma free hemoglobin were maintained below 4 mg/dL. Although further experiments are required, the pump demonstrated the potential for sufficient and reliable performance and biocompatibility in meeting the requirements for cardiopulmonary bypass and 1-week circulatory support.