ABSTRACT
Objective To design a new type of biliary stent to be used in the common bile duct probe and evaluate its biocompatibility, safety and effectiveness in a canine model.Methods Magnesium alloy (AZ 31B) was used to make biliary stents.A canine model of acute obstructive jaundice was established by ligating the distal end of the common bile duct.These dogs were divided into two groups with either placement of magnesium stent or not.The incidence of bile duct leakage and survival were evaluated.Meanwhile, we determined the concentration of magnesium in various body fluids and organs, liver function test, and ultrasonic and histological studies.Results The concentrations of magnesium in the blood, feces, liver, heart, brain and lungs were similar between the two groups.Bile leakage rate in experimental group and control group was 0％ and 16.7％, respectively.The mortality was 16.7％ and 33.3％.There were no significant differences in ALP and TBIL between experimental group and control group (P>0.05) before building and bile duct exploration.There were significant differences in ALP andTBIL between the two groups one and three months after bile duct probe (P<0.05).Biliary tract specimens showed obviously anastomotic stenosis performances and expansion performances of extrahepatic biliary in the control group, but in experimental group such changes were not observed.Ultrasonography showed that the patency of biliary anastomosis was good and there was no anastomotic biliary stricture in experimental group.However, progressive stenosis and expansion performances of extrahepatic biliary occurred in control group.There were fewer collagen fibers but more muscle fibers in experimental group than in control group.Conclusion Biliary stent made of magnesium alloy is of good biocompatibility and has the potential to prevent the postoperative stenosis in the common bile duct probe.
ABSTRACT
Objective To investigate the reasonable anticoagulant therapy for patients over sixty five years old in Yunnan-Guizhou plateau after heart biological valve replacement , and study the standard of reasonable anticoagulant therapy. Methods We collected the recent cases by retrospective way . Low-intensity anticoagulation standard INR (1.5~2.5) was used on 130 patients over sixty five years old. The warfarin dose and anticoagulation INR values in different surgery operation were compared when the patients reached the stable anticoagulation status. The frequency of INR values and warfarin dosage were studied. The differences between the patients with high risk factors and the ordinary patients without the high risk factors in INR values and warfarin dosage were investigated. Results The INR values and warfarin doses showed no significant difference (P > 0.05) in different operation groups when they reached stable anticoagulation status. The INR values was 1.94 ± 0.50 and the daily warfarin dose was (2.45 ± 0.82)mg/d. No significant differences in INR values and warfarin doses were found between the high-risk group and the general group (P>0.05) in steady-state. During follow-up, both the incidence rate of thrombosis and general bleeding were 0.77%. Conclusion The precent study showed that the low-intensity anticoagulation INR values (1.5~2.5) can be the standard of reasonable anticoagulation in Yunnan-Guizhou plateau after heart biological valve replacement with satisfactory anticoagulant effect.