BACKGROUND/AIMS: We experimented with different ablation methods and two types of microwave antennas to determine whether microwave ablation (MWA) increases intrahepatic pressure and to identify an MWA protocol that avoids increasing intrahepatic pressure. METHODS: MWA was performed using either a single-step standard ablation or a stepwise increment ablation paired with either a 16-gauge (G) 2-cm antenna or a 14G 4-cm antenna. We compared the maximum pressures and total ablation volumes. RESULTS: The mean maximum intrahepatic pressures and ablation volumes were as follows: 16G single-step: 37+/-33.4 mm Hg and 4.63 cm3; 16G multistep: 31+/-18.7 mm Hg and 3.75 cm3; 14G single-step: 114+/-45.4 mm Hg and 15.33 cm3; and 14G multistep: 106+/-43.8 mm Hg and 10.98 cm3. The intrahepatic pressure rose during MWA, but there were no statistically significant differences between the single and multistep methods when the same gauge antennae were used. The total ablation volume was different only in the 14G groups (p<0.05). CONCLUSIONS: We demonstrated an increase in intrahepatic pressure during MWA. The multistep method may be used to prevent increased intrahepatic pressure after applying the proper power.
Ablation Techniques/instrumentation/*methods ; Animals ; Cattle ; Liver/*physiology/surgery ; Medical Illustration ; *Microwaves ; Models, Animal ; *Pressure

OBJECTIVETo analyze the transmural lesions of different parts of the pig heart atrium received different times of ablation applied with Atricure bipolar radiofrequency system.

METHODSSix fresh (ex vivo time<20 min) pig hearts with atrium preserved intact were used as the experimental objects and experimental groups were divided according to the ablation position. The Atricure bipolar radiofrequency system was applied in the ablation of the parts of the atrium, such as posterior wall of left atrium, anterior wall of left atrium, anterior wall of right atrium and posterior wall of left atrium close to mitral posterior ring. Ablate the position of the atrium lengthened about 2.0 cm with the same thickness with an interval of 0.5 cm for 4 times respectively, also recording the time of every ablation. For each part and each time of ablation, the ablated atrial tissue was preserved with 4% formaldehyde and 5% glutaraldehyde, and was sent for observation under light microscope and transmission electron microscope. The ablation time and lesion were analyzed statistically.

RESULTSIn the same position of the atrium, ablation time decreased with the times of the ablation, in different position of the atrium with same time of ablation, time showed a positive proportion with the thickness of the atrium.

CONCLUSIONSAtricure bipolar radiofrequency system is very safe and efficient, also convenient for manipulation. With regard to the relatively thinner part of the atrium, such as posterior wall and anterior wall of left atrium, at least two times of ablation can ensure transmural lesion of the atrial tissue, but to the position of the atrium such as anterior wall of right atrium and posterior wall of left atrium close to mitral posterior ring, 3 to 4 times of ablation can ensure transmural lesion of the atrial tissue.

Animals ; Catheter Ablation ; instrumentation ; methods ; Heart Atria ; pathology ; In Vitro Techniques ; Swine ; Time Factors

The dot-shaped coagulative necrosis induced by a single HIFU exposure can be considered as a basis for HIFU ablation of tumour. For complete ablation of tumour mass with HIFU, the crucial point is to create a complete line-shaped lesion by way of dot-shaped coagulative necrosis. At the beginning of this in vitro study, a dot-shaped coagulative necrosis with focal width (W) 3mm was induced in ox liver by HIFU (acoustical intensity (I(SAL)) 6500W/cm2; exposure time 1s) at focal depth 2cm. And then, we investigated the formation of line-shaped lesion under two different modes, namely, multiple dot-shaped coagulative necrosis overlapping and linear scanning. Under multiple dot-shaped coagulative necrosis overlapping mode, line-shaped lesion is formed by the combination of multiple dot-shaped coagulative necroses. With acoustical intensity (I(SAL)) 6500W/cm2 and exposure time is for each single exposure, different intervals (D) between two successive single exposures (1mm, 2mm, 2.5mm, 3mm, 4.5mm, 5mm) were applied to obtain line-shaped lesion. Under linear scanning mode, the intensity (I(SAL)) 6500W/cm2 and cycle 1 were set constant, and various scanning speeds (V) 1mm/s, 3mm/s, 6mm/s, 7mm/s were adopted to create line-shaped lesion. After the procedures, the tissues were dissected to obtain the maximum section of the line-shaped lesion. The results were as follows: under multiple dot-shaped coagulative necrosis overlapping mode, a complete line-shaped lesion could be formed when D < or = W, while an incomplete line-shape lesion was formed when D > W; under linear scanning mode, a complete line-shaped lesion could be formed using the scanning speed 3mm/s and cycle 1. The results validate that the complete line-shaped lesion can be created with the dosage and exposure parameters optimized for the dimension of a single dot-shaped coagulative necrosis as shown in this study.
Animals ; Cattle ; Dose-Response Relationship, Radiation ; High-Intensity Focused Ultrasound Ablation ; instrumentation ; methods ; In Vitro Techniques ; Liver ; pathology ; Necrosis

OBJECTIVETo evaluate the safety and efficacy of using the JCS-01 focused ultrasound fat reduction machine for noninvasively breaking fat cells and abdomen sculpting treatment.

METHOD40 qualified subjects were enrolled in the study per the IRB-approved protocol and randomly assigned into trial and control groups. The fat reduction treatments were performed using the JCS-01 focused ultrasound fat reduction machine made by Beijing 3H Medical Technology Co., Ltd. The trial group received ultrasound energy treatment in their abdominal subcutaneous adipose tissue on the 1st and 7th days of the trial. The control group followed the similar procedure except that the ultrasound energy was turned off during treatments. Both the trial and control groups were followed-up on 1,7,14, 35 days post treatment.

RESULTSThe waist circumference measured on 14, 35 days were reduced 2.52 cm +/- 1.04 cm and 3.31 cm +/- 0.67cm in comparison with the baseline values in the trial group, reaching the protocol hypothesis of at least 1.5 cm abdominal circumference reduction, which demonstrated the treatment efficacy. The adverse events included minor and transient thermal sensation and mild pain in the treated abdomen area in the trial group. No other adverse events were observed. Clinical biochemistry assay testing showed that the subjects liver and kidney function indicators had no significant change.

CONCLUSIONIt is safe and effective to use the JCS-01 focused ultrasound fat reduction machine for abdomen fat reduction treatment.

Adult ; Body Fat Distribution ; Cosmetic Techniques ; Female ; High-Intensity Focused Ultrasound Ablation ; adverse effects ; instrumentation ; methods ; Humans ; Male ; Treatment Outcome ; Waist Circumference

UNLABELLEDBased on the T-map of MRI, this research sought to address the relationship between the simulated threshold thermal dose of coagulation and actual the coagulation on histological slides. The MR imaging guided HIFU system was used, the parameters of therapeutic transducer were: frequency--1 MHz, diameter--150 mm, and focal length--150 mm. In fresh beef liver tissue in vitro, sonications were delivered at a fixed depth of 20 mm and at varying powers. The temperature-sensitive MR images obtained during the sonications were used to estimate the temperature, and the thermal dosage of each voxel in the target region was calculated. The thermal dosage of each voxel was compared with the reference threshold thermal dosage, so as to calculate the boundary and area of the coagulated tissue. After the exposure, the tissue was dissected along the maximal section of the coagulation necrosis, and the area of the biological focal region was measured.

RESULTSThe occurrence of tissue damage correlated well with the equivalent thermal dose calculation based on the T-mapping of MRI, and they share the same variation tendency.

CONCLUSIONThe equivalent thermal dose calculation based on the T-Map of MRI correlates well with the actual tissue damage, and so an index to predict the threshold for tissue damage in vivo is provided. This index offers improved online control over minimally invasive thermal treatments and increases the security of the therapy.

Animals ; Cattle ; Dose-Response Relationship, Radiation ; High-Intensity Focused Ultrasound Ablation ; instrumentation ; methods ; Hot Temperature ; therapeutic use ; In Vitro Techniques ; Liver ; radiation effects ; Magnetic Resonance Imaging ; methods ; Radiation Dosage ; Temperature ; Therapy, Computer-Assisted ; methods ; Thermography ; methods ; Ultrasonic Therapy ; methods

OBJECTIVETo investigate the therapeutic and immunological effects of microwave ablation (MA) combined with CpG ODN in mice bearing transplanted colon carcinoma.

METHODSA mouse model bearing colon carcinoma was established by subcutaneously inoculating CT26 cells into the right flank of Balb/c mice. The tumor-bearing mice were randomized into control group with PBS injection in the peritumoral area, MA group, MA combinated with CpG ODN group, and CpG ODN group with CpG ODN injection in the peritumoral area. The tumor volume changes were observed, and serum CD3(+)CD4(+) and CD3(+)CD8(+) T lmyphocytes were analyzed by flow cytometry after the treatments. Serum levels of interleukin (IL)-2, IL-12 and IFN-gamma were detected by ELISA. The mice in the MA group and the combined treatment group showing tumor regression were rechallenged with CT26 cells.

RESULTSNo significant difference was found in the number of serum CD3(+), CD3(+)CD4(+), or CD3(+)CD8(+) T lymphocytes between the 4 groups. The ratio of CD3(+)CD4(+)/CD3(+)CD8(+) T lymphocytes in the combined treatment group and MA group were 1.58-/+0.10 and 1.53-/+0.13, respectively, significantly higher than that in PBS group and CpG ODN group (P<0.05). The serum concentration of IL-2, IL-12 and IFN-gamma in the combined treatment group were 64.6-/+7.4 pg/ml, 314.1-/+26.9 pg/ml and 61.9-/+7.3 pg/ml, respectively, significantly higher than those in the other 3 groups (P<0.05). The tumor formation rate in the combined treatment group was significantly lower than that in MA group (25.0% vs 75.0%, P<0.05).

CONCLUSIONCpG ODN can enhance the immunity and decrease the tumor formation rate following a rechallenge with CT26 cells in mice treated with MA.

Ablation Techniques ; instrumentation ; methods ; Adjuvants, Immunologic ; therapeutic use ; Animals ; Colonic Neoplasms ; immunology ; therapy ; Female ; Immunotherapy ; methods ; Mice ; Mice, Inbred BALB C ; Microwaves ; therapeutic use ; Neoplasm Transplantation ; Oligodeoxyribonucleotides ; therapeutic use ; Random Allocation

Incidence of gastric cancer is high in China and standard radical operation is currently the main treatment for gastric cancer. Postoperative complications, especially some special complications, can directly affect the prognosis of patients, even result in the increase of mortality. But the incidences of these special complications are low, so these complications are often misdiagnosed and delayed in treatment owing to insufficient recognition of medical staff. These special complications include (1) Peterson hernia: It is an abdominal hernia developed in the space between Roux loop and transverse colon mesentery after Roux-Y reconstruction of digestive tract. Peterson hernia is rare and can quickly result in gangrenous ileus. Because of low incidence and without specific clinical symptoms, this hernia does not attract enough attention in clinical practice, so the outcome will be very serious. Once the diagnosis is made, an emergent operation must be performed immediately. Peterson space should be closed routinely in order to avoid the development of hernia. (2) Lymphatic leakage: It is also called chyle leakage. Cisterna chylus is formed by gradual concentration of extensive lymphatic net to diaphragm angle within abdominal cavity. Lymphadenectomy during operation may easily damage lymphatic net and result in leakage. The use of ultrasonic scalpel can decrease the risk of lymphatic leakage in certain degree. If lymphatic leakage is found during operation, transfixion should be performed in time. Treatment includes total parenteral nutrition, maintenance of internal environment, supplement of protein, and observation by clamp as an attempt. (3)Duodenal stump leakage: It is one of serious complications affecting the recovery and leading to death after subtotal gastrectomy. Correct management of duodenal stump during operation is one of key points of the prevention of duodenal stump leakage. Routine purse embedding of duodenal stump is recommend during operation. The key treatment of this complication is to promt diagnosis and effective hemostasis.(4) Blood supply disorder of Roux-Y intestinal loop: Main preventive principle of this complication is to pay attention to the blood supply of vascular arch in intestinal edge. (5) Anastomotic obstruction by big purse of jejunal stump: When Roux-en-Y anastomosis is performed after distal radical operation for gastric cancer, anvil is placed in the remnant stomach and anastomat from distal jejunal stump is placed to make gastrojejunal anastomosis, and the stump is closed with big purse embedding. The embedding jejunal stump may enter gastric cavity leading to internal hernia and anastomotic obstruction. We suggest that application of interruptable and interlocking suture and fixation of stump on the gastric wall can avoid the development of this complication.
Anastomosis, Roux-en-Y ; adverse effects ; China ; Chylous Ascites ; etiology ; prevention & control ; therapy ; Duodenum ; blood supply ; surgery ; Gastrectomy ; adverse effects ; methods ; mortality ; Gastric Outlet Obstruction ; etiology ; prevention & control ; Gastric Stump ; surgery ; Hemostatic Techniques ; Hernia ; etiology ; prevention & control ; therapy ; High-Intensity Focused Ultrasound Ablation ; instrumentation ; Humans ; Jejunum ; blood supply ; surgery ; Lymph Node Excision ; adverse effects ; instrumentation ; Lymphatic System ; injuries ; Postoperative Complications ; classification ; diagnosis ; mortality ; prevention & control ; Prognosis ; Stomach ; surgery ; Stomach Neoplasms ; complications ; surgery ; Suture Techniques ; standards ; Thoracic Duct ; injuries ; Wound Closure Techniques ; standards