Concomitant cardiac and hepatic hemangiomas

Primary tumors of the heart are rare with a reported incidence of about 0.002% to 0.3% at autopsy. A cardiac hemangioma is a form of benign primary cardiac tumor that often presents with atypical clinical symptoms. Hemangiomas are generally isolated lesions. Here, we report a patient with previous hepatic hemangioma who later was found to have a large coexistent cardiac hemangioma presenting with cardiac compressive symptoms.     

Extension of Pindborg tumor to the maxillary sinus: a case report

The calcifying epithelial odontogenic tumor is a benign epithelial odontogenic lesion that accounts for less than 1% of all odontogenic tumors. It is most frequently seen in the posterior areas of the mandible. Extension of this lesion to the maxillary sinus is extremely rare. In this paper, we report the fourth of such cases which has been reported, up to now. This tumor was encased between the right maxillary lateral and canine roots with extension to the maxillary sinus. Histologically, the tumor is composed of sheets of epithelial cells with eosinophilic or clear cytoplasm, intercellular bridges, nuclear pleomorphism, but no mitotic figures, amorphous eosinophilic and calcified materials were seen within the sheets of epithelial cells.     

Mortality and morbidity after aortic root replacement: 10-year experience

Aortic root reconstruction remains a challenging surgical procedure. This retrospective study was carried out to evaluate the early and long-term outcomes of aortic root replacement over a 10-year period. There were 83 patients with a mean age of 43.2 +/- 14 years (range, 10 to 78 years). Type A aortic dissection and Marfan syndrome were found in 28% and 24%, respectively. The most common technique used for repair of this condition was the Bentall operation. The mean duration of follow-up was 29.6 +/- 28 months, ranging from 1 to 120 months. Hospital (30-day) mortality was 13.3% (11 patients). Two patients died during the late follow-up. The mortality was significantly higher in patients presenting with cardiogenic shock, those with long cardiopulmonary bypass and crossclamp times, and the group who had concomitant coronary artery bypass grafting. Emergency operation was not a significant risk factor for early death in our patients. The most common complications were bleeding and neurological sequelae. Aortic root replacement can be achieved with acceptable mortality and morbidity in a high-risk group of patients. Improvements in the outcome may be achieved by faster transport of patients in cardiogenic shock, and by reducing the cardiopulmonary bypass and crossclamp times.     

A Hybrid Algorithm for Prediction of Varying Heart Rate Motion in Computer-Assisted Beating Heart Surgery

An essential requirement for performing robotic assisted surgery on a freely beating heart is a prediction algorithm which can estimate the future trajectory of the heart in the varying heart rate (HR) conditions of real surgery with a high accuracy. In this study, a hybrid amplitude modulation- (AM) and autoregressive- (AR) based algorithm was developed to enable estimating the global and local oscillations of the beating heart, raised from its major and minor physiological activities. The AM model was equipped with an estimator of the heartbeat frequency to compensate for the HR variations. The RMS of the prediction errors of the hybrid algorithm was in the range of 165–361 μm for the varying HR motion, 21% less than that of the single AM model. With the capability of providing highly accurate predictions in a wide range of HR variation, the hybrid model is promising for practical use in robotic assisted beating heart surgery.     

On the Morphological Deviation in Additive Manufacturing of Porous Ti6Al4V Scaffold: A Design Consideration

Additively manufactured Ti scaffolds have been used for bone replacement and orthopaedic applications. In these applications, both morphological and mechanical properties are important for their in vivo performance. Additively manufactured Ti6Al4V triply periodic minimal surface (TPMS) scaffolds with diamond and gyroid structures are known to have high stiffness and high osseointegration properties, respectively. However, morphological deviations between the as-designed and as-built types of these scaffolds have not been studied before. In this study, the morphological and mechanical properties of diamond and gyroid scaffolds at macro and microscales were examined. The results demonstrated that the mean printed strut thickness was greater than the designed target value. For diamond scaffolds, the deviation increased from 7.5 μm (2.5% excess) for vertical struts to 105.4 μm (35.1% excess) for horizontal struts. For the gyroid design, the corresponding deviations were larger, ranging from 12.6 μm (4.2% excess) to 198.6 μm (66.2% excess). The mean printed pore size was less than the designed target value. For diamonds, the deviation of the mean pore size from the designed value increased from 33.1 μm (−3.0% excess) for vertical struts to 92.8 μm (−8.4% excess) for horizontal struts. The corresponding deviation for gyroids was larger, ranging from 23.8 μm (−3.0% excess) to 168.7 μm (−21.1% excess). Compressive Young’s modulus of the bulk sample, gyroid and diamond scaffolds was calculated to be 35.8 GPa, 6.81 GPa and 7.59 GPa, respectively, via the global compression method. The corresponding yield strength of the samples was measured to be 1012, 108 and 134 MPa. Average microhardness and Young’s modulus from α and β phases of Ti6Al4V from scaffold struts were calculated to be 4.1 GPa and 131 GPa, respectively. The extracted morphology and mechanical properties in this study could help understand the deviation between the as-design and as-built matrices, which could help develop a design compensation strategy before the fabrication of the scaffolds.