Blood flow characteristics of the bilateral internal thoracic artery: implications of optimal graft configuration for coronary artery bypass grafting to maximize blood supply.

PURPOSE: There is controversy regarding which internal thoracic artery (ITA) should be anastomosed to the left anterior descending artery (LAD). Here, we propose an optimal graft design based on measurement of blood flow in the ITA. METHODS: Sixty-one patients (53 men, median age 68 [62-75] years) undergoing first elective coronary artery bypass grafting were enrolled. Fifty-seven left ITAs (LITAs) and 28 right ITAs (RITAs) were harvested in either a semi-skeletonized manner using a harmonic scalpel covered with papaverine-soaked gauze (group-A, n = 45) or a fully skeletonized manner using electrocautery with intraluminal papaverine injection (group-B, n = 41). Free flow of 33 ITAs was measured after pharmacological dilatation and in situ ITA-LAD flow was measured in 59 patients by transit-time flowmetry. RESULTS: RITA and LITA free flow were 147.0 [87.8-213.0] mL/min and 108.0 [90.0-144.0] mL/min, respectively (P = 0.199). The group-B had significantly higher ITA free flow (135.0 [102.0-171.0] mL/min) than group-A (63.0 [36.0-96.0] mL/min, P = 0.009). In 13 patients with bilateral ITA harvesting, free flow of the RITA (138.0 [79.5-204.0] mL/min) was also significantly higher than the LITA (102.0 [81.0-138.0] mL/min, P = 0.046). There was no significant difference between RITA and LITA flow anastomosed to the LAD. The group-B had significantly higher ITA-LAD flow (56.5 [32.3-73.6] mL/min) than group-A (40.9 [20.1-53.7] mL/min, P = 0.023). CONCLUSION: RITA provides significantly higher free flow than LITA but similar blood flow to the LAD. Full skeletonization with intraluminal papaverine injection maximizes both free flow and ITA-LAD flow.

Guidelines for cadaver dissection in education and research of clinical medicine (The Japan Surgical Society and The Japanese Association of Anatomists).

This article translates the guidelines for cadaver surgical training (CST) published in 2012 by Japan Surgical Society (JSS) and Japanese Association of Anatomists from Japanese to English. These guidelines are based on Japanese laws and enable the usage of donated cadavers for CST and clinical research. The following are the conditions to implement the activities outlined in the guidelines. The aim is to improve medicine and to contribute to social welfare. Activities should only be carried out at medical or dental universities under the centralized control by the department of anatomy under the regulation of Japanese law. Upon the usage of cadavers, registered donors must provide a written informed-consent for their body to be used for CST and other activities of clinical medicine. Commercial use of cadavers and profit-based CST is strongly prohibited. Moreover, all the cadaver-related activities except for the commercial-based ones require the approval of the University's Institutional Review Board (IRB) before implementation. The expert committee organized at each university for the implementation of CST should summarize the implementation of the program and report the details of the training program, operating costs, and conflicts of interest to the CST Promotion Committee of JSS.

Guidelines for cadaver dissection in education and research of clinical medicine (The Japan Surgical Society and The Japanese Association of Anatomists).

This article translates the guidelines for cadaver surgical training (CST) published in 2012 by Japan Surgical Society (JSS) and Japanese Association of Anatomists from Japanese to English. These guidelines are based on Japanese laws and enable the usage of donated cadavers for CST and clinical research. The following are the conditions to implement the activities outlined in the guidelines. The aim is to improve medicine and to contribute to social welfare. Activities should only be carried out at medical or dental universities under the centralized control by the department of anatomy under the regulation of Japanese law. Upon the usage of cadavers, registered donors must provide a written informed-consent for their body to be used for CST and other activities of clinical medicine. Commercial use of cadavers and profit-based CST is strongly prohibited. Moreover, all the cadaver-related activities except for the commercial-based ones require the approval of the University's Institutional Review Board (IRB) before implementation. The expert committee organized at each university for the implementation of CST should summarize the implementation of the program and report the details of the training program, operating costs, and conflicts of interest to the CST Promotion Committee of JSS.

Autophagy during left ventricular redilation after ventriculoplasty: Insights from a rat model of ischemic cardiomyopathy.

OBJECTIVES: Myocardial autophagy has been recognized as an important factor in heart failure. It is not known whether changes in ventricular geometry by left ventriculoplasty influence autophagy in ischemic cardiomyopathy. We hypothesized that myocardial autophagy plays an important role in left ventricular (LV) redilation after ventriculoplasty. METHODS: Four weeks after ligation of the left anterior descending artery, ventriculoplasty or sham operation was performed. The animals were euthanized at 2 days (early) or 28 days (late) after the second operation. Ventricular autophagy was evaluated by protein expression of microtubule-associated protein light chain 3 II, an autophagosome marker. Cardiomyocyte area was assessed by histologic examination. LV function was evaluated by echocardiography. To examine the implications of autophagy, an autophagy inhibitor (3-methyladenine) was injected intraperitoneally for 3 weeks before sacrifice. RESULTS: The LV was reduced in size early and redilated late after ventriculoplasty. LV systolic function was improved early and later worsened after ventriculoplasty. Light chain 3 II expression decreased early after ventriculoplasty and increased in the late period. Myocyte area increased from the early to late stage after ventriculoplasty. Autophagic inhibition exaggerated the increased myocyte hypertrophy and LV redilation. CONCLUSIONS: In a rat model of myocardial infarction, autophagy decreased early after ventriculoplasty and increased again during LV redilation. These results provide new insights into the mechanism underlying the late failure of ventriculoplasty.

A Nationwide Survey of Surgical Treatment for Severe Ischemic Mitral Regurgitation.

OBJECTIVE: Mitral subvalvular procedures in addition to restrictive annuloplasty are promising for ischemic mitral regurgitation (IMR). However, the prevalence and efficacy of specific subvalvular repair in severe IMR have not been elucidated. This is the first nationwide survey regarding surgeons' attitudes toward IMR in Japan. METHODS: A questionnaire was sent to 543 institutions. From 2015 to 2019, numbers of elective first-time mitral valve replacement (MVR) with/without complete chordal preservation (CCP)/papillary muscle approximation (PMA) and mitral valvuloplasty (MVP) with/without papillary muscle relocation (PMR)/PMA in patients with severe IMR were collected. Concomitant procedures for coronary artery, tricuspid valve, and arrhythmia could be included but left ventricular reconstruction was excluded. RESULTS: Completed questionnaires were received from 286 institutions (52.7%). The majority (90%) had less than 20 cases within 5 years. The number of MVP (1413, 61.5%) surpassed MVR (886, 38.5%). CCP was performed in half of MVR (50.0%), while PMA was included in only 1.9% of MVR. PMA and PMR were also performed infrequently, in only 7.7% and 10.9% of MVP, respectively. CONCLUSION: Japanese surgeons aggressively perform MVP for severe IMR. Subvalvular repair was also aggressively performed in addition to MVR, but not to MVP. A multicenter registry study is in progress.

Reduction of tethering distance by papillary muscle tugging approximation with mitral valve replacement for non-ischemic functional mitral regurgitation induces left ventricular reverse remodeling.

BACKGROUND: Functional mitral regurgitation (FMR) is caused by left ventricular (LV) remodeling and subsequent tethering of the mitral valve (MV). If LV remodeling is irreversibly advanced, it could not be attenuated by the MV procedure alone, although the additional subvalvular procedure could induce LV reverse remodeling by forcibly reducing MV tethering. This study aimed to assess the anti-tethering effect of papillary muscle tugging approximation (PMTA) on LV reverse remodeling after mitral valve replacement (MVR) for non-ischemic FMR. METHODS: The study subjects were 19 patients who underwent MVR with and without PMTA [MVR + PMTA (n = 11) and MVR alone (n = 8), respectively] for non-ischemic FMR. The tethering distance (TD) and LV end-systolic volume (ESV) at the preoperative, postoperative, and follow-up periods were assessed in terms of their correlation and time-dependent changes. The intra-LV energy efficiency was also evaluated through vector flow mapping analysis. RESULTS: TD and ESV were comparable between both procedures preoperatively and did not change after MVR alone. In MVR + PMTA, however, a significant decrease was identified in TD and ESV at the early postoperative and follow-up periods, respectively [TD = 48, 30, and 31 mm (p < 0.001) and ESV = 159, 133, and 82 mL (p < 0.001) at the preoperative, postoperative, and follow-up periods, respectively]. Finally, at follow-up, the extent of change from the preoperative value in ESV significantly correlated with that in TD (ρ = 0.81, p < 0.001 for overall; ρ = 0.93, p < 0.001 for MVR + PMTA; ρ = 0.86, p = 0.011 for MVR alone). The ratio of TD to ESV was also significantly correlated with systolic energy loss to LV stroke work after MVR + PMTA (ρ = 0.81, p = 0.015). CONCLUSIONS: PMTA for non-ischemic FMR could induce LV reverse remodeling depending on the extent of postoperative TD reduction. A smaller TD to ESV was associated with a higher intra-LV energy efficiency after PMTA + MVR.

Simple Chordal Replacement With a Newly Designed "Mitral Plate" in Mitral Valvuloplasty.

Mitral valvuloplasty using GORE-TEX as the artificial chordae is often associated with difficulties in determining the length of the artificial chordae, achieving the correct artificial chordae length, and preventing knot slippage, especially for beginners. We describe a simple technique involving a novel device called the "Mitral Plate," which enables surgeons to automatically determine the correct length of the artificial chordae and tie slippery knots without performing excessive saline tests.

A novel approach for the complete extraction of large tumours in video-assisted thoracoscopic surgery.

BACKGROUND: Video-assisted thoracoscopic (VATS) lobectomy has recently become the standard for treating lung cancer. However, the complete removal of large tumours from the chest cavity is often difficult. Therefore, we developed a novel approach to extract large tumours from the wound without rib resection or fracture (the eXtraction of resected specimens through the Lower INterCostal route [XLINC] method). SUBJECTS AND METHODS: In XLINC, a skin incision is made on the tenth intercostal space, and the resected lung tissue is extracted. This retrospective study included patients who underwent VATS lobectomy using XLINC in our institution from 2016 to 2018. As a control group, six patients who had undergone thoracotomy during VATS surgery due to a large tumour diameter were included in the conversion group. RESULTS: Four men and six women (median age = 66 years, maximum median tumour diameter = 59 mm) were included in the study. The median length of the wound incision for XLINC was 4.5 (range: 4-8) cm. The median operative time was 183 min, and the estimated blood loss was 50 ml. Rib resection was not required, and no fractures were noted. The median length of hospital stay was 8 days. No patients developed major complications caused by XLINC. There were no significant differences, except in operation time and amount of blood loss, between the two groups. However, the XLINC group used fewer post-operative analgesics. CONCLUSION: Our report suggests that XLINC might be a simpler, less invasive procedure that could be used in patients with large tumours.

Non-heart transplant surgical approaches with mitral valve operation and surgical ventricular reconstruction for non-ischaemic dilated cardiomyopathy: a Japanese multicenter study.

OBJECTIVES: There is uncertainty over the efficacy of additional surgical ventricular reconstruction (SVR) associated with mitral valve operation for non-ischaemic dilated cardiomyopathy (DCM). This study aims to assess mid-term outcomes of these non-heart transplant surgical approaches for DCM. METHODS: We reviewed retrospectively 106 patients (median age 64, 44 females) who underwent isolated mitral annular plasty (MAP; n = 34), mitral valve replacement (MVR; n = 29), and SVR associated with MAP (SVR + MAP; n = 43) for DCM, in 11 Japanese hospitals. We analysed mid-term outcomes, specifically freedom from cardiac death and cardiac event. RESULTS: Hospital deaths occurred in 16 patients (15.1%) and cardiac deaths in 36 patients (34.0%) during the study period of 4.4 ± 3.5 years. Freedom from cardiac death at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 79.1%, 82.6%, and 29.5% (P < 0.0001). Freedom from cardiac event at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 42.8%, 59.9%, 22.6% (P = 0.0004). In the multivariable analyses, preoperative tricuspid regurgitation (TR) grade was the only risk factor for both cardiac death and event, whereas MVR for DCM emerged as a protective factor for cardiac event. CONCLUSIONS: This study could not show any benefit of additional SVR, by means of volume reduction, to MAP, because the baseline characteristics were different even after the stratification of DCM grade. MVR can be performed with favorable mid-term outcomes even in patients with advanced DCM, while patients undergoing MAP with/without SVR had more frequent MR recurrence or cardiac events. Interestingly, the right ventricular feature is a predictor of both cardiac death and events, with the TR grade being a predictor of poor mid-term outcomes.

Bridge-to-Bridge Left Ventricular Assist Device Implantation Strategy vs. Primary Left Ventricular Assist Device Implantation Strategy.

BACKGROUND: The bridge-to-bridge (BTB) strategy, a conversion to durable left ventricular assist device (LVAD) after stabilization using surgical temporary mechanical circulatory supports for a couple of months, is not uncommon in Japan. However, its effect on clinical outcomes in comparison with a primary durable LVAD implantation strategy remains unknown.Methods and Results:Data of 837 consecutive patients (median age 45, 73% males) who underwent durable LVAD implantation as BTB (n=168) or primary implant (n=669) between April 2011 and April 2019 were retrospectively reviewed from the prospective multicenter Japanese mechanically assisted circulatory support registry. The BTB group was younger and had comparable end-organ function, better hemodynamic profile, and longer operative time compared with the primary implant group at baseline. The 3-year survival was 80% vs. 87% (P=0.007) for the BTB and primary implant groups respectively, with greater observed rates of stroke and infection as the predominant causes of death. The BTB strategy was independently associated with increased 3-year mortality (hazard ratio 2.69 [1.43-5.07], P=0.002) in addition to other significant risk factors. CONCLUSIONS: The BTB cohort had comparable baseline characteristics to the primary implant cohort at the time of durable LVAD conversion, but had lower 3-year survival. Detailed analysis clarifying the causality of this finding should improve outcomes with the BTB strategy.

Correlation between increased atrial expression of genes related to fatty acid metabolism and autophagy in patients with chronic atrial fibrillation.

Atrial metabolic disturbance contributes to the onset and development of atrial fibrillation (AF). Autophagy plays a role in maintaining the cellular energy balance. We examined whether atrial gene expressions related to fatty acid metabolism and autophagy are altered in chronic AF and whether they are related to each other. Right atrial tissue was obtained during heart surgery from 51 patients with sinus rhythm (SR, n = 38) or chronic AF (n = 13). Preoperative fasting serum free-fatty-acid levels were significantly higher in the AF patients. The atrial gene expression of fatty acid binding protein 3 (FABP3), which is involved in the cells' fatty acid uptake and intracellular fatty acid transport, was significantly increased in AF patients compared to SR patients; in the SR patients it was positively correlated with the right atrial diameter and intra-atrial electromechanical delay (EMD), parameters of structural and electrical atrial remodeling that were evaluated by an echocardiography. In contrast, the two groups' atrial contents of diacylglycerol (DAG), a toxic fatty acid metabolite, were comparable. Importantly, the atrial gene expression of microtubule-associated protein light chain 3 (LC3) was significantly increased in AF patients, and autophagy-related genes including LC3 were positively correlated with the atrial expression of FABP3. In conclusion, in chronic AF patients, the atrial expression of FABP3 was upregulated in association with autophagy-related genes without altered atrial DAG content. Our findings may support the hypothesis that dysregulated cardiac fatty acid metabolism contributes to the progression of AF and induction of autophagy has a cardioprotective effect against cardiac lipotoxicity in chronic AF.

Hemocompatibility-related Adverse Events Following HeartMate II Left Ventricular Assist Device Implantation between Japan and United States.

Background: Left ventricular assist device (LVAD) therapy has improved the clinical outcomes in advanced heart failure patients, however, this may differ between countries. We aimed to compare outcomes between Japanese and US LVAD cohorts. Methods: For 416 consecutive LVAD patients who received HeartMate II LVAD implantation and completed a one-year follow-up, age-matched Japanese patients (the Japanese registry for mechanically assisted circulatory support (J-MACS) group) and the US patients were compared for their clinical outcomes. Results: 154 J-MACS patients and 77 US patients were compared. Survival, free from hemocompatibility-related adverse events (HRAEs) in the J-MACS was statistically comparable with the US (75% vs. 63%, p = 0.79). J-MACS had more disabling strokes than the US (0.221 vs. 0.052/patient-year, p = 0.005), whereas there was less nonsurgical bleeding (0.045 vs. 0.117/patient-year, p = 0.024). The net hemocompatibility score was statistically comparable between the groups (1.54 vs. 1.19 points/patient, p = 0.99). Post-LVAD prothrombin time with international normalized ratio (INR) <1.5 (odds ratio 4.07) was a risk factor for HRAEs in J-MACS, whereas INR >3.0 (odds ratio 5.71) was a risk factor in the US (p < 0.05 for both). Conclusion: In the age-matched cohorts, the J-MACS group experienced more strokes, while the US group had more bleedings. "Tailor-made" therapeutic strategy might be required for each country, given the unique variation of HRAE incidence among each country.

Refractory Right Ventricular Failure in a Patient with Emery-Dreifuss Muscular Dystrophy.

A 23-year-old man had progressive muscle weakness and Emery-Dreifuss muscular dystrophy (EDMD) due to a LMNA (lamin A/C) mutation. Congestive heart failure diagnosed at 19 years of age. Maximal drug treatment/cardiac resynchronization failed to improve the cardiac function. He was therefore hospitalized due to heart failure. Despite extracorporeal membrane oxygenation, he developed severe right heart dysfunction and died (multiple organ failure). A cardiac lesion's presence determines the prognosis of EDMD. While there are many arrhythmia reports, few reports on heart failure (particularly severe heart failure requiring cardiac transplantation) have been published. Right heart function monitoring and early ventricular-assist device use plus right heart support considering heart transplantation are important.

Perioperative changes of the slope in the preload recruitable stroke work relationship by a single-beat technique after mitral valve surgery in functional mitral regurgitation with non-ischemic dilated cardiomyopathy.

OBJECTIVES: The slope in the preload recruitable stroke work relationship is a highly linear, load-insensitive contractile parameter. However, the perioperative change of the slope has not been reported before. We examined the perioperative slope from a steady-state single beat in patients with functional mitral regurgitation and assessed the correlation with brain natriuretic peptide (BNP) levels. METHODS: The study included 16 patients with non-ischemic dilated cardiomyopathy and refractory heart failure: 10 patients underwent mitral valve plasty and left ventricular plasty (MVP + LVP group) and 6 patients who underwent mitral valve replacement and papillary muscle tugging approximation (MVR + PMTA group). The left ventricular ejection fraction was assessed by the modified Simpson method; the slope was assessed by the single-beat technique using transthoracic echocardiography. BNP levels were measured by chemiluminescent immunoassay. RESULTS: The left ventricular ejection fraction and slope did not significantly change from pre- to early post-surgery in the MVP + LVP group. Both the left ventricular ejection fraction and slope significantly increased 6 months after surgery in the MVR + PMTA group. Postoperative BNP level was low in the MVR + PMTA group. While the postoperative left ventricular ejection fraction did not correlate with BNP levels, the postoperative slope significantly correlated with BNP level after surgery in the MVP + LVP group and in the total functional mitral regurgitation group. CONCLUSIONS: The change of slope was dependent on surgical procedures. In functional mitral regurgitation, the slope may be a more sensitive parameter in reflecting the left ventricular contractile function than the left ventricular ejection fraction.

Forns Index is a predictor of cardiopulmonary bypass time and outcomes in Fontan conversion.

Recent reports suggested that cardiopulmonary bypass (CPB) time is one of the risk factors for postoperative complications after Fontan conversion. Although Fontan conversion may be performed for the patients with hepatic fibrosis after initial Fontan procedure, there is no predictive indicator regarding the liver function associated with hemostasis which can affects CPB time. Thirty-one patients who underwent Fontan conversion using the same surgical procedure (extracardiac conduit conversion with right atrium exclusion) were enrolled. In multivariate analyses including age at Fontan conversion, interval from initial Fontan to conversion, hemodynamic data such as right atrial pressure, ventricular end-diastolic pressure, and cardiac index, hepatic data such as platelet count, prothrombin time international normalized ratios, serum total bilirubin, hyaluronic acid levels, five known indices for hepatic fibrosis (Forns Index, APRI, FIB4, FibroIndex, and MELD-XI), and liver stiffness measured by ultrasound elastography, only the Forns Index remained independently associated with the CPB time (P < 0.01) and blood transfusions (plasma transfusions and platelet concentrations: P < 0.01 for both). The cutoff level for Forns Index to predict the prolonged CPB time (exceeding 240 min) was 4.85 by receiver-operating characteristic curve (area under the curve 0.823, sensitivity 76.9%, and specificity 72.2%). Three patients with Forns Index > 7.0 had poor outcomes with long CPB time and massive blood transfusions in contrast with the other 28 patients. In conclusion, Forns Index could serve as a practical predictor of CPB time and is associated with blood transfusion volume in Fontan conversion.

Feasibility and safety of reduced-port video-assisted thoracoscopic surgery using a needle scope for pulmonary lobectomy- retrospective study.

BACKGROUND: This study aimed to determine the usefulness and limitations of videoassisted thoracoscopic (VATS) lobectomy using one-window and puncture method (1WPM). METHODS: This study involved 14 patients who underwent lobectomy using the 1WPM at our institute from 2008 to 2017. RESULTS: The study patients comprised of 3 men and 11 women with a median age of 10.5 years (range, 0-72 years). There were eight cases in children younger than 18 years old and the youngest patient was 9 days old. The diagnoses were congenital pulmonary cystic disease (n = 7), primary lung cancer (n = 4), metastatic lung tumor (n = 1), and others (n = 2). The 1WPM was successful in 9 of 14 patients (64.3%) and, in 5 cases (35.7%), needed conversion to either two-window method (TWM) using additional port (n = 3) or open thoracotomy (n = 2). The causes for conversion were need for additional bronchoplasty or lymph node dissection (n = 3), failure of one-lung ventilation (n = 1), and presence of a small thoracic cavity that made the procedure extremely difficult (n = 1). In the group that was successfully treated with 1WPM, the median values were as follows: operation time, 193 min (range, 112-480 min); blood loss, 0 ml (range, 0-90 ml); drainage duration, 1 day (range, 1-4 days); and postoperative hospital stay, 7 days (range, 4-13 days). CONCLUSIONS: Lobectomy by 1WPM can be safely performed and has good postoperative course and this procedure can be applicable and effective in small infants.