Objective To assess the efficiency and safety of pulsatile catheter (PUCA) pump support during acute ischemic heart failure in sheep. Methods After heart failure model was induced successfully in 10 sheep, PUCA pump was inserted through aorta and the aortic valve orifice with its tip located in the left ventricle. It was then activated to support the hemodynamics for 3 hours. Hemodynamic parameters were monitored and recorded before thoracotomy, heart failure, and every 60 min after the support. Platelet and plasma free hemoglobin were tested during the experiment. Thrombosis in kidney, membrane-pump, and catheter were examined at the end of study. Results PUCA pump support was successful in 7 sheep for 3 hours and failed in 3 due to technical problems. During support with the PUCA pump, mean arterial pressure(MAP), systolic blood pressure (SBP) and diastolic blood pressure(DBP) increased gradually and close to the baseline at the end of experiment. No significant change in platelet and plasma free hemoglobin were found during the whole period of the PUCA pump support. No thrombosis was found as well by means of examining kidney, membrane-pump and catheter. Conclusions PUCA pump can successfully maintain the hemodynamics in a sheep acute heart failure model associated with few blood destruction and thrombosis. It is thus suitable for clinical application to heart failure patients for the maintenance of hemodynamics.
Objective To evaluate clinical efficacy of four-claw Ti-planes for internal fixation of multiple rib fractures and flail chest. Methods Clinical data of 93 patients with multiple rib fractures and flail chest who were admittedto Shanghai Pudong Hospital from December 2011 to November 2012 were retrospectively analyzed. There were 78 male and 15 female patients with their age of 20-80 years. All the patients received internal fixation of rib fractures using four-clawTi-planes. Finite element modeling and analysis were performed to investigate biomechanical behaviors of rib fractures after internal fixation with four-claw Ti-planes. Results The average number of rib fractures of the 93 patients was 5.9±2.1，and each patient received 3.8±1.3 four-claw Ti-planes for internal fixation. The operations were performed 6.3±3.2 days after admission. After the rib fractures were fixed with four-claw Ti-planes，rib dislocations and chest-wall collapse of flail chest were restored，and patients’ pain was relieved. Postoperative CT image reconstruction of the chest showed no dislocationor displacement at the fixation areas of the four-claw Ti-planes. Rib fractures were stabilized well，and normal contours of the chest were restored. Finite element analysis showed that the maximum bearable stress of the rib fractures after internal fixation with four-claw Ti-planes was twice as large as normal ribs. Conclusion Clinical outcomes of four-claw Ti-planesfor internal fixation of rib fractures are satisfactory with small incisions and less muscle injury of the chest wall，so this technique deserves wide clinical use.