[Evaluation of the performance of a minimally invasive thoracic drainage tube in a rabbit model of hemothorax].

OBJECTIVE: To assess the performance of a minimally invasive thoracic drainage tube (14 F) made of polyurethane (PU) in a rabbit model of hemothorax in comparison with the conventional 28 F chest tube (CCT). METHODS: Thirty New Zealand rabbits were divided into experimental chest tube (ECT) group (n=9), CCT group (n=6), and blood provider group (n=15). Blood samples (20 mL) collected from the blood providing rabbits were injected into the chest cavity of the rabbits in the other two groups, and the time taken for closed drainage of the thoracic cavity was recorded. The rabbits in ECT and CCT groups were subjected to blood injections (20 mL for each injection) into the chest cavity every 20 min for 5 times, and the volumes of blood drained by ECT and CCT were measured. Two hours later, the rabbits were sacrificed and the residual blood and blood clots in the chest cavities were observed. RESULTS: Compared with CCT, the use of ECT significantly shortened the operation time (P<0.05) and produced more effective blood drainage at 20 min and 40 min after the placement of the drainage tube (P<0.05). No significant difference was found in the total blood volume drained between ECT and CCT groups, but the volume of residual blood in the thoracic cavity was significantly smaller in ECT group than in CCT group. No post-operative complications were found in the rabbits in ECT group while all the rabbits in CCT group had abutment pressure to the lung. CONCLUSION: Compared to CCT, ECT is less invasive and allows more effective thoracic drainage with more convenient operation and reduced postoperative complications, suggesting its potential for use in closed thoracic drainage in single-port video-assisted thoracoscopic surgery (VATS) or in pediatric patients.

[Establishment of a rabbit model of small diameter vascular graft replacement].

OBJECTIVE: To establish an rabbit model that mimics the hemodynamics of the bypass graft after coronary artery bypass surgery. METHODS: Sixteen New Zealand rabbits were randomly divided into two groups for abdominal aortic artery replacement using a 3-cm-long ePTFE graft with an inner diameter 4 mm through an incision at 1/3 from the middle to the lower part of the abdomen (group A) or in the lower abdomen (group B). The general conditions of the rabbits, operative time, number of collateral vessels that needed to be ligated, rate of massive intraoperative bleeding, fluctuation of vascular anastomosis after surgery, patency rate of the graft on day 7 after the operation were compared between the two groups. RESULTS: The two groups of rabbits had similar body weight, diameter of the abdominal aortic artery, intraoperative bleeding rate and occlusion rate of the vascular graft at 7 days after the procedure. The operative time was longer in group A, but the difference was not statistically significant. In group A, the number of the vascular branches that needed to be ligated was smaller and the rate normal femoral artery pulsation was higher than those in group B. CONCLUSION: It is feasible to establish models of small diameter vascular graft replacement in rabbits, and the patency rate of the graft can be monitored by observation of the general condition and ultrasound examination of the rabbits.

[Experience with coronary artery bypass grafting and concomitant procedures in 21 cases].

OBJECTIVE: To review our experience with coronary artery bypass grafting (CABG) and its concomitant procedures. METHODS: From December, 1998 to December, 2002, 21 patients underwent CABG and their clinical data were analyzed. RESULTS: Nineteen patients were discharged uneventfully after the procedure. Early death occurred in 2 patients who received emergency operation after acute myocardial infarction. Among the 18 patients followed up, angina was eliminated in all but one patient. CONCLUSION: Although the concomitant procedures such as valve replacement may prolong the operation time for CABG, good clinical outcome of the patients can still be expected by implementation of intensive perioperative management and complete myocardial revascularization.

[Minimally invasive closure of atrial septal defect without extracorporeal circulation: report of 5 cases].

OBJECTIVE: To review our experience with a new surgical approach for closure of atrial septal defect (ASD) through a minimally invasive method without extracorporeal circulation. METHODS: Five female patients (age range, 7-38 years) with secondary atrial septal defect ranging from 1.8 to 3.4 cm, underwent minimally invasive closure under ultrasonic cardiography guidance. RESULTS: The ASD was closed successfully in all of the 5 cases without residual shunt or displacement of occluder. The mean hospital stay was 7 days. CONCLUSION: This minimally invasive surgical approach is an easy and safe voay for clinical application.

[Hemocompatibility evaluation in vitro of small-caliber expanded polytetrafluoroethylene vessel with silk fibroin coating sulfonated by low temperature plasma].

OBJECTIVE: To evaluate the hemocompatibility of a small-caliber expanded polytetrafluoroethylene vessel with silk fibroin coating sulfonated by low temperature plasma treatment. METHODS: The composite blood vessel was prepared by first coating the small-caliber expanded polytetrafluoroethylene vessel with silk fibroin followed by sulfonation by low temperature plasma treatment. After hemolysis test in vitro, dynamic coagulation time test, blood platelet adhesion test, and recalcification time test were performed to evaluate the hemocompatibility of the composite blood vessel. RESULTS: Scanning electronic microscopy revealed obvious platelets adhesion on the conventional artificial (control) vessel, which seldom occurred on the composite vessel. The curve of absorbance-clotting time of the composite vessel declined more slowly than that of the control vessel. The recalcification time of the composite blood vessel averaged 603 s, significantly longer than that of the control vessel (480 s, P = 0.000). CONCLUSION: The composite blood vessel has good antithrombotic activity and hemocompatibility as a promising vascular prosthesis.