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Minimally invasive cardiac surgery (MICS) using a small surgical incision in children provides less physical stress. However, concern about safety due to the small surgical field has been noted. Recently, the authors developed a modified MICS procedure to extend the surgical field. This report assesses the safety and benefit of this modified procedure by comparing three procedures: the modified MICS (group A), conventional MICS (group B), and traditional open heart surgery (group C). A retrospective analysis was performed with 111 pediatric patients (age, 0-9 years; weight, 5-30 kg) who underwent cardiac surgery for simple cardiac anomaly during the period 1996-2010 at Juntendo University Hospital. The modified MICS method to extend the surgical view has been performed since 2004. A skin incision within 5 cm was made below the nipple line, and the surgical field was easily moved by pulling up or down using a suture or a hemostat. The results showed no differences in terms of gender, age, weight, or aortic cross-clamp time among the groups. Analysis of variance (ANOVA) indicated significant differences in mean time before cardiopulmonary bypass (CPB), CPB time, operation time, and bleeding. According to the indices, modified MICS was similar to traditional open surgery and shorter time or lower bleeding volume than conventional MICS. No major mortality or morbidity occurred. In conclusion, the modified MICS procedure, which requires no special techniques, was as safe as conventional open heart surgery and even reduced perioperative morbidity. [ABSTRACT FROM AUTHOR]

Objective: The chordal cutting method is performed for mitral valve tenting in functional mitral regurgitation, such as ischemic mitral regurgitation. However, the method may interfere with the mitral valvular–ventricular continuity. To maintain the continuity and the natural force direction between the papillary muscles and the mitral annulus after chordal cutting, we developed “translocation” of the secondary chordae tendineae. Methods: Six mongrel dogs had sonomicrometry crystal markers implanted in the left ventricle, mitral annulus, and papillary muscle tips. After the secondary chordae tendineae of the anterior mitral leaflet from each papillary muscle were resected, each papillary muscle tip was connected to the mid-anterior mitral annulus with 4-0 polypropylene sutures, and then the sutures were taken out of the left atrium to control the chordal tension. The condition under which the artificial chordae were released was defined as “redundant.” The chordal tension of 15 g of weight was defined as “taut,” whereas the tension for 2-mm chordal shortening after “taut” was defined as “tight.” After the dogs were weaned from cardiopulmonary bypass, hemodynamic and 3-dimensional data were acquired under the condition of “redundant,” and then “taut,” “tight,” and “redundant.” Results: End-systolic elastance increased from 1.81 ± 0.24 mm Hg/mL to 2.69 ± 0.89 mm Hg/mL (P = .015) between “redundant” and “taut,” and this was maintained between “taut” and “tight.” However, preload recruitable stroke work increased from 41.3 ± 12.0 mm Hg to 58.1 ± 19.7 mm Hg (P = .005) between “redundant” and “taut,” and was reduced to 51.7 ± 22.9 mm Hg (P = .037) between “taut” and “tight.” Conclusion: “Translocation” of the secondary chordae tendineae after chordal cutting improved left ventricular systolic function compared with simple chordal cutting. [Copyright &y& Elsevier]

Abstract: Objectives: The aim of this study is to evaluate the relationship between left ventricular (LV) wall property and the results of LV volume reduction surgery (LVR) to treat dilated cardiomyopathy (DCM) in an experimental model. Methods: DCM was introduced in 18 Lewis rats by autoimmunization with cardiac myosin. Among them, 12 rats underwent LVR and the rest were served as controls. They were subjected to echocardiography and cardiac catheterization for dimensional and functional measurements. The animals were sacrificed 4 weeks after surgery, and the fraction of myocardial fibrosis was calculated in 4 divided parts of the LV wall. Results: Percent fibrosis varied widely from 4.7 to 45.2%. LV volume reduction surgery improved cardiac function immediately after surgery in all rats (Emax, 0.28±0.14 to 0.48±0.18mmHg/μl; LV end-diastolic pressure, 21.0±6.1 to 13.3±5.1mmHg, P<0.05, respectively). Four weeks later, 6 hearts remained in good shape with smaller LV end-diastolic dimension (Dd) than baseline values (LV Dd, 9.7±0.6mm; fractional area change (FAC), 40.3±8.4%) and the other 6 had more redilation in diameter and more deterioration in function than baseline values (LV Dd, 10.9±0.6mm; FAC, 25.8±6.9%; P<0.05, respectively). Percent fibrosis in the septum differed 11.1±3.4 vs. 27.8±2.8% between the two groups (P<0.01). There was a significant correlation between the ratio of LV redilatation after surgery and percent fibrosis in the septum (r=0.951, P<0.01). Conclusions: Although the initial benefit of LVR was confirmed, the long-term result was affected by the amount of residual fibrosis. This information suggests that surgical site selection is important to achieve a good result of LV restoration surgery for DCM. [Copyright &y& Elsevier]