Association of computed tomography-derived muscle mass and quality with delayed acquisition independent walking after cardiovascular surgery.

BACKGROUND: In the context of cardiovascular surgery, the foremost concern lies in delayed functional recovery, as typified by the acquisition of independent walking after surgery, among older patients with decline in skeletal muscle mass and quality. Computed tomography (CT), which is typically employed for the preoperative assessment of pathological conditions in patients undergoing cardiovascular surgery, is also suitable for screening for potential decline in skeletal muscle mass and quality. The aim of this study was to examine the predictive capabilities of CT-derived parameters such as muscle mass and muscle quality for the delayed acquisition of independent walking in the postoperative period. METHODS: This retrospective study enrolled consecutive Japanese patients who underwent elective cardiovascular surgery between May 2020 and January 2023. In total, 139 patients were included in the analyses. Based on the preoperative CT image, the psoas muscle volume index (PMVI) and psoas muscle attenuation (PMA) were calculated. Information on patient characteristics, including preoperative physical fitness such as handgrip strength/body mass index (GS/BMI), short physical performance battery (SPPB), and 6-min walking distance (6MWD), were obtained from the medical records. We defined delayed acquisition of independent walking after surgery as the inability to walk 100 m within 4 days after surgery. RESULTS: The median age of the patients was 72 (interquartile: 64-78) years, and 74.8% (104/139) were men; 47.5% corresponded to the delayed group. The areas under the curves of SPPB, GS/BMI, 6MWD, PMVI, and PMA against delayed acquisition of independent walking after surgery were 0.68 [95% confidence interval (CI): 0.59 to 0.77], 0.72 (95% CI: 0.63 to 0.80), 0.73 (95% CI: 0.65 to 0.82), 0.69 (95% CI: 0.60 to 0.78), and 0.78 (95% CI: 0.70 to 0.85), respectively. In the multivariate logistic regression analysis, low PMA was significantly associated with delayed acquisition of independent walking even after adjustment for patient characteristics including physical fitness [model 1: SPPB (OR, 1.14; 95% CI: 1.03-1.25), model 2: GS/BMI (OR, 1.13; 95% CI: 1.03-1.25), and model 3: 6MWD (OR, 1.14; 95% CI: 1.03-1.25)], but PMVI was not. CONCLUSIONS: Our study revealed a strong association between PMA, a marker of CT-derived muscle quality, and the postoperative delay in achieving independent walking in patients who underwent cardiovascular surgery. The technique to obtain information on muscle quality during the time period before surgery may be an option for timely therapeutic intervention in patients who may have delayed acquisition of independent walking after surgery.

Intimal Flap Vegetation Following Aortic Root Re-dissection.

A 75-year-old man who had undergone ascending aorta replacement for acute Type A aortic dissection presented with a recurring high fever. Transesophageal echocardiography revealed that a vegetation had formed on the re-dissected intimal flap of the noncoronary sinus of Valsalva. This didactic case suggests that antibiotic prophylactic measures be considered for aortic dissection flaps as for irregular valves susceptible to infective endocarditis.

Surgical resection of two independent primary intimal sarcomas in the left atrium.

Primary intimal sarcoma of the heart is an extremely rare tumor that is known to have a very poor prognosis. We present a case of a 65-year-old man who suffered from deteriorating congestive heart failure due to a severe mitral stenosis caused by a large mobile left atrial tumor. The patient underwent an emergency operation of the tumor in the left atrium. The tumor was attached to the inferior wall of the left atrium. After the resection of the tumor, a second tumor on the interatrial septum, which had not been detected in the preoperative investigation, was discovered and resected. The patient developed acute respiratory failure soon after the operation and succumbed to his illness. The appearance of the main tumor was cauliflower-like, which strongly suggested the possibility of malignancy. Immunohistochemistry revealed that the neoplastic cells were positive for vimentin, desmin, p16, and especially murine double minute 2 (MDM-2). The first tumor was CD34 positive and cdk4 negative, but the second tumor was more anaplastic and CD34 negative and cdk4 positive, which suggests a different origin of the two tumors. The two tumors were diagnosed as intimal sarcomas by MDM-2, which is currently considered a conclusive marker. This is an exceptionally rare case of two simultaneous and possibly independent primary intimal sarcomas in the left atrium.

[Severe Perioperative Coronary Artery Spasm in Thoracic Aortic Surgery; Report of Two Cases].

We report 2 cases of severe perioperative coronary artery spasm in thoracic aortic surgery. Case 1 was a 72-year-old male with a distal arch aneurysm of 74 mm while case 2 was a 74-year-old male with acute type A aortic dissection. We performed thoracic aortic repair (total arch replacement and ascending aorta replacement) under moderately hypothermic circulatory arrest (25 °C) and selective cerebral perfusion in both cases. ST elevation, abnormal left ventricular wall motion, and hypotension were noted intraoperatively. Because we were not able to wean the patients from the cardiopulmonary bypass, intraaortic balloon pump was initiated in case 1 and a coronary artery bypass graft was added in case 2. In addition to using vasodilators such as diltiazem, case 1 recovered without further intervention, but case 2 developed cardiopulmonary arrest and needed resuscitation on postoperative day 5 because of recurrence of coronary spasm. Perioperative coronary artery spasm is rare especially in aortic surgery, and may become lethal. Early recognition and special hemodynamic support is required.

Giant atrial septal aneurysm originating from the right coronary artery.

Giant coronary artery aneurysm is a rare clinical entity and its involvement in the interatrial space is extremely rare. We here report the rare surgical case of a 67-year old man with giant right coronary artery aneurysm located in the atrial septum with fistula formation to the right atrium, complicated with congestive heart failure, rapid atrial fibrillation and left atrial appendage thrombus. The patient eventually recovered fully without sequelae.

Acute coronary artery bypass graft failure in a patient with polycythemia vera.

Polycythemia vera in patients undergoing cardiac surgery is clinically rare. A 65-year-old man with polycythemia vera was admitted with effort-related chest discomfort. We planned coronary artery bypass grafting for left anterior descending artery and obtuse marginal branch stenosis, using bilateral internal thoracic arteries, with perioperative prophylactic management to avoid thromboembolism. His internal thoracic arterial grafts occluded during and after surgery due to thrombus, and ST-elevation myocardial infarction developed, which needed a percutaneous coronary intervention. This case suggests that optimal management methods should be studied further to contribute to better patient outcomes in this condition.

[THERAPEUTIC POTENTIAL OF MICRORNA IN THE FIELD OF CARDIOVASCULAR SURGERY].

Because the number of heart failure patients increases every year, improved prevention and treatment for damaged hearts are needed. Many investigators have explored new approaches to improve cardiac function, including cell transplantation and gene therapy. MicroRNAs comprise a novel class of endogenous, small, noncoding RNAs that negatively regulate gene expression via degradation or translational inhibition of their target mRNAs. Recent studies have described microRNAs as fine-tuners of gene expression. New therapeutic strategies for heart failure using microRNAs such as cardiac reprogramming therapy by overexpression of microRNAs in murine infarcted hearts and prevention of cardiac remodeling using antagomirs in hypertensive rat models are promising technologies for future clinical application. Moreover, microRNAs could possibly function as biomarkers of heart failure. MicroRNA-145 is a specific mediator of the regulation of the vascular smooth muscle cell phenotype. We reported that transduction of microRNA-145 into vein grafts may be a novel option for preventing vein graft disease after surgical revascularization, since its transduction reduced neointimal thickness in the rabbit model of vein graft disease. Although several issues regarding microRNAs need to be overcome, their therapeutic potential holds considerable promise, and they will hopefully be combined with surgical strategies in the near future.

Acute subdural hematoma after aortic surgery: a retrospective comparative study.

BACKGROUND: Acute subdural hematoma is uncommon following open-heart surgery, but may result in increased mortality and morbidity. METHODS: A retrospective analysis was performed involving all patients who underwent thoracic aortic surgery from January 2009 to February 2013. There were 53 patients who had thoracic aortic repair with open distal anastomosis and required selective cerebral perfusion with or without retrograde cerebral perfusion. We evaluated the incidence of postoperative acute subdural hematoma. The patients were divided into two groups: a subdural hematoma group who had symptomatic subdural hematoma postoperatively, and a non-subdural hematoma group who had no subdural hematoma. The variables were compared between the 2 groups. RESULTS: Eight (15.1%) patients had a transient symptomatic subdural hematoma; none required surgical evacuation of the hematoma. There were significant differences between the two groups in terms mean and maximum retrograde cerebral perfusion flow, and the volume of intraoperative platelet transfusion. Multivariate analysis revealed that a significant risk factor for acute subdural hematoma following thoracic aortic surgery was the amount of intraoperative platelet transfusion (odds ratio = 0.9, 95% confidence interval: 0.81-0.98, p = 0.015). CONCLUSIONS: This retrospective study demonstrated that the subdural hematoma group received fewer units of platelets, thus it appears to be important to give platelets appropriately. Strict flow regulation or avoidance of retrograde cerebral perfusion is suggested.

Right atrial volume reduction for severely impaired pulmonary function.

We report a patient with giant right atrium and severe pulmonary dysfunction who underwent successful surgical volume reduction with significant improvement of pulmonary function studies.

Effect of microRNA-145 to prevent vein graft disease in rabbits by regulation of smooth muscle cell phenotype.

OBJECTIVE: Because microRNA-145 (miR-145) is a specific mediator in the regulation of the proliferation and differentiation of smooth muscle cells, we investigated the effect of miR-145 on the intimal hyperplasia in the rabbit model of vein graft disease using electroporation-mediated gene transfer. METHODS: The right jugular vein of male Japanese white rabbits was harvested and transduced with miR-145-encoding plasmids using an electroporator and then interposed in the carotid artery. At 2 or 4 weeks postoperatively, the venous graft was explanted, and the intimal thickness and intima/media area ratio were evaluated. Furthermore, 3 days after implantation, the myocardin and serum response factors were measured using real-time polymerase chain reaction. At 2 weeks after implantation, immunohistochemical investigations using mature smooth muscle markers, myosin heavy chain smooth muscle-1 and -2, and proliferation marker Ki-67 were performed. RESULTS: MiR-145 transduction significantly reduced the neointimal thickness at both 2 and 4 weeks (2 weeks, 52.1 ± 15.7 vs 113.2 ± 26.9 µm, P < .05, n = 6; 4 weeks, 42.4 ± 4.8 vs 136.5 ± 38.3 µm, P < .05, n = 8), and it also significantly reduced the intima/media area ratio at 4 weeks (0.22 ± 0.04 vs 1.13 ± 0.23, P < .01, n = 8). Additionally, it upregulated the mRNA expression level of myocardin compared with that in the grafts that did not receive gene transfer. Smooth muscle-2 and Ki-67 expression revealed that miR-145 transduced grafts contained more smooth muscle-2-positive mature smooth muscle cells and fewer Ki-67-positive proliferating cells. CONCLUSIONS: Nonviral transduction of miR-145 into the bypass graft could be a novel option for preventing intimal hyperplasia in vein graft disease.

Flat fibrin thrombus deposition on tissue valve after aortic valve replacement.

Bioprosthetic valves have a lower thrombogenicity than mechanical valves, thus long-term systemic anticoagulation can be avoided. Herein, we present an extremely rare case of fibrin thrombus formation on tissue valve, which was observed during the second operation 2 years after the initial operation by chance. This report gives us a word of caution regarding the thrombus formation on the bioprosthetic valves that could be unaware of the presence for the long term.

Composite arterial Y graft has less coronary flow reserve than independent grafts.

BACKGROUND: It is not known whether a composite Y graft of the left internal thoracic artery can provide sufficient blood flow to the whole left coronary system. The aim of this study was to compare regional myocardial blood flow (MBF) and coronary flow reserve after coronary artery bypass grafting using arterial composite Y graft or independent arterial grafts. METHODS: Positron emission tomography was performed at rest and after dipyridamole infusion using oxygen-15-labeled water 2 weeks after coronary artery bypass grafting. Regional MBF was calculated in seven segments of the left ventricle. Coronary flow reserve was defined as the ratio of MBF after dipyridamole infusion to MBF at rest. In the Y graft group (n = 22), a free arterial graft to obtuse marginal arteries was anastomosed to the proximal side of in situ left internal thoracic artery, which was anastomosed to the left anterior descending artery. In the independent graft group (n = 13), left anterior descending and obtuse marginal arteries were independently revascularized using in situ left internal thoracic artery and a free arterial graft. RESULTS: There was no difference between the groups in MBF at rest. Coronary flow reserve in the Y graft group was lower than that in the independent group in the anterobasal (1.43 +/- 0.07 versus 1.90 +/- 0.13, p = 0.038), apical (1.24 +/- 0.06 versus 1.64 +/- 0.12, p = 0.003), septal (1.34 +/- 0.05 versus 1.75 +/- 0.13, p = 0.023), and lateral regions (1.19 +/- 0.04 versus 1.66 +/- 0.09, p = 0.001). CONCLUSIONS: Although arterial composite Y graft improved MBF at rest, it was not as effective as independent grafts for improving coronary flow reserve soon after coronary artery bypass grafting.