胸部外科

Surgical strategy for non-ischemic dilated cardiomyopathy （NIDCM） is currently controversial. Subjects were 20 patients who underwent left ventriculoplasty（LVP） from 2006 to 2013 and 6 patients who underwent papillary muscle tugging approximation （PMTA） after 2015. PMTA is a new trans-mitral approach combined with valve replacement without left ventriculotomy. Another group of patients（ n＝14）who were registered for heart transplantation（ HTx） after 2013 was also analyzed for left ventricular assist device（LVAD） free survival. Mw（ slope in the preload recruitable stroke work relationship） calculated by single beat technique using echocardiography was employed as a load-independent cardiac functional parameter. The baseline characteristics and Mw were not different between the LVP and PMTA groups. One-year survival was significantly lower in the LVP group（53％）than in the PMTA group（100％）［log-rank：p＝0.024］. In the HTx group, early LVAD implantation was necessary in the patients who had low Mw（＜20）at the time of registration. In conclusion, PMTA would be one option for NIDCM patients（ non-HTx candidates） with severe mitral regurgitation. Early LVAD implantation might be predicted in HTx candidates with low Mw（＜20）．

Surgery for functional mitral regurgitation （FMR） and dilated cardiomyopathy （DCM） remains a challenge. We reviewed our efforts；anterior （i.e. physiological） relocation of papillary heads and muscles（PHO） in 54 patients with FMR and simplified ventricular restoration of uni-directional Dor or Frozen-Apex restoration in 22 patients with DCM. Actuarial survival 4 years after the PHO was 92±6％ with improved left ventricular （LV） function and well controlled FMR. Results of the simplified restoration was also promising with no hospital death and just 1 cardiac death late postoperatively, with good symptom relieve and maintained LV function. Surgical outcome for FMR or DCM may be further improved.

Objectives: The effects of restrictive mitral annuloplasty （RMA） on subvalvular geometry remains unknown. We evaluated changes in left ventricular（LV） function, severity of mitral regurgitation（MR） and leaflet tethering parameters after RMA and clarified their associations. Methods: In 44 patients with clinically-relevant functional MR who underwent RMA, distances between papillary muscle（ PM） tips and anterior mitral annulus（ PM-tethering distance）, leaflet angles relative to lines connecting annuli, and interpapillary muscle distance（ IPMD） were serially quantified. Results: One month after surgery, LV function and MR severity improved with decreased anterior （34±5 to 30±4 mm） and posterior PM-tethering distance （37±4 to 32±4 mm）, anterior-leaflet angle （ALA）［32±8 to 22±7 degree］, and IPMD （31±6 to 25±5 mm）, while these variables remained abnormal and posterior-leaflet angle （PLA） increased （34±8 to 48±14 degree）［p＜0.01 for all］. During follow-up （66±37 months）, these effects were maintained in 33 patients without MR recurrence, whereas 11 with it showed worsened tethering with less LV function recovery. Multiple linear regression analyses identified that change in MR severity from baseline to 12-month examination independently associated with corresponding change in IPMD （parameter estimate of 0.100 with standard error of 0.039, p＝0.019） and that in posterior PM- tethering distance（ parameter estimate of 0.104 with standard error of 0.045, p＝0.035）, while not with change in PLA. The IPMD change was independently associated with change in LV end-systolic dimension （parameter estimate of 0.299 with standard error of 0.110, p＝0.013）. Conclusions: RMA procedure partially relieved leaflet tethering, evidenced by decreased tethering distances and IPMD；the latter was the main determinant of MR. These beneficial effects might be mainly attributed to post-RMA reverse LV remodeling, potentially offsetting the negative effect of augmented PLA in selected patients.

We applied cardiac resynchronization therapy with an implantable cardioverter-defibrillator（ CRT-D） and with concomitant cardiac surgery to 2 patients with left ventricular （LV） systolic dysfunction and dyssynchronous ventricular activation. A patient had severe ischemic dilated cardiomyopathy with coronary artery aneurysms （LV ejection fraction 12％， LV diastolic dimension 81 mm, LV systolic dimension 75 mm and atrial fibrillation, with complete left bundle branch block）. Another patient had severe dilated cardiomyopathy with mitral valve regurgitation （LV ejection fraction 25％， LV diastolic dimension 75 mm, LV systolic dimension 61 mm atrial fibrillation, and complete left bundle branch block）. Both epicardial LV leads were surgically implanted on the posterolateral wall. CRT-D achieved the resynchronization of the LV contraction, and improved cardiac function. The patients had an uneventful postoperative course and were discharged from hospital after operation. A key advantage of surgical epicardial lead placement is that lead placement is not confined to anatomic branches of the LV venous circulation as is the case with transvenous placement. CRT-D combined with cardiac surgery might be available for patients with LV systolic dysfunction.

In the era of implantable ventricular assist device （VAD）， the role of extracorporeal VAD is changing. The extracorporeal VAD was ever the mainstream of treatment for severe heart failure. Now, it is mainly applied to patients with severe cardiogenic shock. Recently the centrifugal pump available for cardiopulmonary bypass system has been often used as the extracorporeal VAD because of its simplicity of management. Although the implantable VAD plays the pivotal role for bridge to transplantation since its clinical introduction in 2011, the extracorporeal VAD still has the important role for end-stage heart failure and cardiogenic shock. We have experienced 47 cases of the extracorporeal VAD until now. Here, based on our experience, we describe the “past and present” role of the extracorporeal VAD and mention the future aspect of the extracorporeal VAD.

Temporary mechanical circulatory support device has been highly advocated for severe cardiogenic shock patient. However, standard ventricular assist device （VAD） implantation is invasive procedure for these sick patients. Less-invasive cardiac procedures are known to be generally associated with many beneficial effects such as reduction of trauma, blood loss and risk of infection, and relatively short intensive care unit stay. Here we describe an alternative technique for less invasive extracorporeal VAD implantation.

Background：Salvage rates for patients requiring extracorporeal membrane oxygenation （ECMO）due to acute cardiogenic shock remain poor due to difficulties in decision making on optical timing of ECMO removal or conversion to ventricular assist devices（ VAD）. Method：From 2005 to 2018, 37 patients supported with ECMO due to acute circulatory deterioration were referred to our department for implantation of VAD. Their outcomes were analyzed using multi-variate analysis to assess the risk factors of VAD implantation, and we adopted a new decision-tree to improve the outcomes. Results：Four patients had severe cerebral complications and 2 patients suffered severe infection. Those 6 patients were withdrawn from VAD implantation. ECMO could be removed in 6 patients, but one of them underwent VAD implantation due to the intraaortic balloon pumping （IABP） -dependent circulatory condition. In total, 25 patients underwent VAD implantation. Four patients reached to heart transplantation. Six patients remain on VAD. VAD was explanted due to recovery in 2 patients. Statistically significant risk factors by multi-variate analysis on 2-year mortality were preoperative necessity of renal replacement （p＝0.006） and T-Bil （p＝0.051, ＞4.0 mg/dl）. Two-year survival of patients without end-organ dysfunction was 83.3％．However, 2-year survival of patients with end-organ dysfunction was miserable （23.1％）. Based on these findings, we applied to a new decision-tree with 4 steps from 2016；① rule out strokes and sepsis, ② End-organ dysfunction should be treated before VAD implantation with proper management of mechanical circulatory support to recover end-organ dysfunction, ③ urgent conversion to VAD if there is no aortic valve opening, ④ conversion to VAD if cardiac functional recovery cannot be observed within 5 to 7 days. According to this decision-tree, 3 patients underwent VAD implantation after recovery from end-organ failure and survived in 2016. Conclusions：Our experiences of salvage from ECMO in patients with severely impaired cardiac function suggest that end-organ dysfunction（ necessity of renal replacement and T-Bil＞4.0 mg/dl） was a strong risk factor for mid-term mortality. Those patients should undergo VAD implantation after recovery from end-organ dysfunction.