Ultrasound Evaluation Of The Value Of Superior Vena Cava Obstruction, Experimental And Clinical Study

Objective: (1) To study the feasibility of setting up an model of superior vena cava obstruction (SVCO) in rabbit by infusing VX2 tumor cell suspension via ultrasound-guidance transcutaneously and evaluate the application of this animal model.(2) To study morphologic and hemodynamic changes of superior vena cava (SVC) in rabbits with SVCO due to VX2 tumor and obtain two-dimensional and Doppler image characteristics and explore the relationship between the tumor size and two-dimensional ultrasonic feature, and the relationship between the tumor oppression and Doppler images in order to supply experimental evidence for diagnosing this disease.(3) To analyze ultrasonographic characteristics and histopathological changes in rabbits with SVCO due to VX2 tumor after radiotherapy and observe radiotherapeutic effects and provide the diagnostic message for the SVC syndrome clinically.Materials and methods: (1) Fifteen adult healthy New Zealand White rabbits were enrolled in the modeling SVCO experiment. The VX2 tumor cell suspension was prepared under the sterile condition. About 0.1ml tumor cell suspension was infused in front of SVC outside close to its anterior wall under proper pressure by ultrasound-guidance transcutaneously. The SVC lumen and wall morphology, hemodynamics changes and the tissues around SVC were examined with two-dimensional and Doppler ultrasonography once every 3 days from the 9th day after injection of tumor cell suspension until rabbit natural death. These findings were compared with those by CT and digital subtraction angiography (DSA). The dead rabbits were dissected immediately and the samples were collected for pathologic examination.(2) Fourteen rabbit models with SVCO due to VX2 tumor were detected by two-dimensional and Doppler ultrasonography. The sizes of the tumor and SVC, and hemodynamics changes of SVC in 14 rabbit models were observed and detected with the transducer placed in the right supraclavicular region view by Sequoia 512 computed ultrasonograph once every 3 days from the 12th day after injection. The parameters of SVC detected by ultrasonography were compared with those before inoculation. The ultrasonographic findings were compared and analyzed with those of CT and autopsy sample respectively.(3) Thirteen rabbits with SVCO due to VX2 tumor were enrolled in this study. The tumors in mediastina were exposured one minute with 2gy everyday by SIEMNS MEVATRON 6745, which was 10 times in all. The sizes of the tumor and SVC, SVC velocities and echo feature in 13 rabbits were observed and detected with the transducer placed in the right supraclavicular region view by Sequoia 512 computed ultrasonograph before radiotherapy, on 10th day, on 17thday and on 24th day after radiotherapy. Mediastina neoplasm tissue before and after radiotherapy was sampled for HE dyeing and TUNEL to analysis the number of the apoptotic cells.(4) Ketamine Hydrochloride Injection as an anesthetic in this experiment was injected into muscles in posterior leg of rabbits at a dose of 30mg/kg. Sequoia 512 computed ultrasonograph with a probe 7v3c was used in this study.(5) The transfer of culture method in rabbits: About 0.1ml tumor cell suspension was infused in muscles of the posterior leg or subdermal tissues. When the tumor diameter was 0.5cm-1.0cm, the tumor could be moved for tumor cell suspension.Results: (1) Out of 15 rabbits for modeling SVCO 14 rabbits presented that the tumors were growing in para-SVC and/or SVC cavity by ultrasonography. The diameters of the tumors were (80.70+4.28) mm. Only 1 rabbit dropped out of this study because no tumor grew in para-SVC until 42nd day after infusion. The success rate in implanting tumor was about 93.33%. Of 14 rabbits with tumors, 8 rabbits were visualized that SVC were oppressed on the 15 day after infusion with two-dimensional ultrasonography. An aliasing mosaic flow signal and the high velocity spectra in SVC were displayed with Doppler ultrasonography. The stenotic flow images of SVC in 4 rabbits with tumors were shown on the...