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Hemostasis Of Active Bleeding From Liver Using Percutaneous Microwave Coagulation Therapy Under Contrast-enhanced Ultrasound Guidance: An Experimental Study

Posted on:2009-06-04Degree:DoctorType:Dissertation
Country:ChinaCandidate:H P SongFull Text:PDF
GTID:1114360245998555Subject:Medical imaging and nuclear medicine
Abstract/Summary:PDF Full Text Request
Part One: Differential Diagnosis of Hepatic Hematoma and Hepatic Hematoma with Active Bleeding by Contrast Enhanced UltrasoundObjective: To evaluate the value of contrast enhanced ultrasound in differential diagnosis of hepatic hematoma and hepatic hemotoma with active bleeding. Methods: After Rabbits (n = 15) were heparinized, a self-made impactor was used to impact liver to create the hepatic blunt injury model, and then an 18G semi-automatic biopsy needle was used to created hepatic active bleeding in 10 of the animals by injuring hepatic artery. After the procedure, both unenhanced and enhanced scans were performed to evaluate hepatic injury and search hematomas and active bleeding sites, and in an attempt to identify the specific location of the bleeding sites. After the sonographic studies were finished, each abdomen was opened to see if the injury of liver is identical with the results of sonographic studies.Results: Totally 15 liver injury animal models were created. Unenhanced imaging confirmed 9 hematomas and/or fluids adjacent to liver (9/15), but failed to suggest the presence of active bleeding (0/10). While contrast enhanced imaging confirmed 15 hematomas (15/15), and identified 10 active bleeding (10/10). Active bleeding displays in contrast enhanced imaging as contrast agent extravasating from the injured liver parenchyma. The results of pathology studies were basically matched the results of sonographic studies.Conclusions: Contrast enhanced ultrasound is a rapid and effective diagnosis method on differential diagnosis hepatic hematoma and hepatic hematoma with active bleeding. Contrast agent extravasating from the injured liver parenchyma is the key sign in their differential diagnosis.Part Two: Feasibility Study on Rapidly Coagulation of Hepatic Active Bleeding Site with MicrowaveObjective: To test the feasibility of using microwave to produce rapid hemostasis of liver active bleeding. Methods: New Zealand White rabbits (n = 12; weight, 2.5 ~ 3.5 kg) were anesthetized, and their livers were exposed. After the animals were heparinized, they were randomly into 80 W group, 60 W group and control group (3 animals in each group). An 18 G semi-automatic biopsy needle was inserted 1 cm into the hepatic parenchyma, injuring the hepatic small artery to create active bleeding. The microwave antenna was posed to the bleeding site worked with 80 W and 60 W. A corresponding site of active bleeding in another animal without application of microwave served as a control. There are about 3 ~ 5 hepatic active bleeding sites were created in one animal. Paired comparisons were performed among three groups. Blood loss was assessed by weighing surgical sponges with blood from each bleeding site. Significant differences in blood loss, hemostasis time and carbonization rate were tested.Results: 80 W and 60 W groups showed significantly less mean blood loss than control group (0.09±0.12 g vs 1.83±0.52 g, P < 0.05;0.10±0.10 g vs 1.83±0.52 g, P < 0.05; within 1 min). There was no significant difference of blood loss between 80 W group and 60 W group, P > 0.05. 80 W has less hemostasis time than 60 W group (13.1±4.2 s vs 18.3±7.9 s, P < 0.05), but has higher carbonization rate than 60 W group (81.25% vs 31.25%, P < 0.05). After microwave coagulation, active bleeding was reduced or arrested, and a round or oval coagulated zone around the microwave antenna tract was visual instead. Conclusions: Coagulation with microwave is a rapid and effective method of arresting hepatic active bleeding. 60 W could effectively induce hemostasis without significant carbonization, and the time duration is 10 s to 40 s. Part Three: Application Study on Hemostasis of Active Bleeding from Liver Using Percutaneous Microwave Coagulation Therapy under Real-time Contrast-enhanced Ultrasound GuidanceObjective: To investigate in a close setting, the feasibility of real-time contrast-enhanced ultrasound guided percutaneous microwave coagulation therapy controlling active bleeding made in rabbit livers.Methods: 20 liver active bleeding Rabbits model, which were produced with an 18 gauge semi-automatic biopsy needle and self-made impactor. They were confirmed with contrast-enhanced ultrasound, and randomly into two groups: percutaneous microwave coagulation therapy group (n = 10; the microwave antenna was placed into the bleeding site under ultrasonography guidance and worked with 60 W 30 s in average), and control group (n = 10; the active bleeding site was not treated). Lactated Ringer's solution resuscitation was then given to in both groups to maintain the mean arterial pressure at 70 mm Hg for 1 hour. The Intraperitoneal blood loss, total resuscitation fluid, mean arterial pressure and hematocrit were recorded. Macroscopic examinations were performed at the end of the study.Results: Contrast-enhanced ultrasound located the active bleeding site with the sign of contrast agent extravasation. After percutaneous microwave coagulation therapy, the former bleeding site showed in contrast-enhanced ultrasound imaging as a round or oval contrast agent absent area. Percutaneous microwave coagulation therapy group had a lower blood loss (28.5±6.2 versus 100.8±16.6 ml, P < 0.05) and a lower total resuscitation volume (52.5±15.8 ml versus 167.0±40.8 ml, P < 0.05) than control group. The mean hematocrit value in percutaneous microwave coagulation therapy group was significantly higher than control group (0.26±0.05 versus 0.19±0.04, P < 0.05) at the end of the experiment. Conclusions: Contrast-enhanced ultrasound guided percutaneous microwave coagulation therapy significantly decreased blood loss in a rabbit model of liver active bleeding. It provides a simple, quick, effective and accurate method to control blood loss in liver injury with active bleeding model.
Keywords/Search Tags:Liver, Active bleeding, Hematoma, Contrast Enhanced Ultrasound, Blunt abdominal injury, Microwave, Hemostasis, Active bleeding, Contrast-enhanced ultrasound, Liver, Interventional therapy
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