| Part One Preliminary evaluation effect about radiofrequency ablationand microwave ablation on normal ventilation lung model byCTObjective: Establish RF and microwave ablation models on normal ventilation pig lungs respectively, and evaluate the ablation effects preliminary by CT scan.Methods: 6 healthy pigs, 12 lungs, two ablation regions on each side, left or right respectively, coming to 24 focus. Perform radiofrequency ablation(RFA) on the left lungs of all the 12 pigs under CT guiding, and microwave ablation(MWA) on the right ons,CT guiding similarly. Melting at the same time, 10-minute long at a time, perform CT scan every other once during the process of melting, get images of the ablation area growth over time. Measure and compare the melting maximum longitudinal diameter(L), maximum transverse diameter(D), horizontal cross-section area, volume, and the ratio of transverse and longitude.Results: Do measures on CT images, from 1 to 10 minutes respectively,radiofrequency ablation maximum longitudinal diameter L(cm) 2.60±0.47; 2.93±0.51; 3.20±0.35; 3.41±0.39; 3.58±0.49; 3.63±0.43;3.72±0.42;3.80±0.44;4.08±0.46;4.23±0.35。Maximum transverse diameter(D)(cm) 0.97±0.13;1.57±0.15;1.89±0.33;2.10±0.41;2.19±0.40;2.39±0.45;2.65±0.46;2.92±0.23;3.08±0.40;3.09±0.18.Transverse and longitudinal ratio(D/L) 0.38±0.05;0.55±0.08;0.60±0.12;0.62±0.12;0.61±0.11;0.66±0.11;0.71±0.09;0.77±0.06;0.76±0.09;0.73±0.05.On CT images, measuring 1 to 10 minutes of microwave ablation L(cm) 2.98±0.37;3.92±0.31;4.22±0.35;4.35±0.30;4.48±0.26;4.57±0.33;4.83±0.33;5.07±0.32;5.20±0.35;5.34±0.39. D(cm) 1.90±0.46;2.23±0.72;2.50±0.62;2.63±0.57;2.84±0.57;3.06±0.49;3.41±0.39;3.79±0.50;3.83±0.51;3.83±0.44. D/L 0.64±0.13;0.57±0.17;0.59±0.13; 0.60±0.11; 0.63±0.12; 0.67±0.10; 0.71±0.07; 0.75±0.08;0.74±0.08;0.72±0.07. Ablating after 10 minutes, estimate radiofrequency ablation cross-sectional area S(10.27±1.24)cm2;Volume(V)(21.25±3.60)cm3;Microwave ablation S(16.15±2.79)cm2; V(41.96±12.02)cm3.Conclusion:1 In CT images, the results of microwave ablation area of the largest longitudinal diameter, maximum transverse diameter, cross-sectional area and volume were all greater than radio frequency ablation’s, at the same time, the growth of ablation area is faster than radiofrequency ablation.2 At the beginning, RFA areas is more slender compared with MWA, what the MWA is more close to the ball, but 10 minutes later, there is no significant differences in D/L about the two means.3 In the image, local peripheral bleeding of the ablation area can affect the measurement results of the size and shape of the ablation area, while we can get reliable results by selecting the pathway of the lung that the needle inserting, away from the blood vessels, measuring respectively under 5 and 1 mm slice, and adjusting window width and leave appropriately.4 The pigs can be used to establish the normal ventilation RF and MW ablation model of lung tissue. Part Two The consistency of CT images and pathology after radiofrequency and microwave ablationObjective: Observing the foci’s size, shape, and the corresponding performance in CT images by RFA and MWA, then comparing with the pathological results, and observing the consistency of the two methods.Methods: 6 healthy pigs, 12 lungs, two ablation regions on each side, left or right respectively, coming to 24 foci. Perform radiofrequency ablation(RFA) on the left lungs of all the 12 pigs under CT guiding.Mealt about 10 minutes at the same time, and get ablation CT images. Kill experimental animals by injecting excess does, get integral lungs out and fixed. Parallel CT scan 5 mm slice, observe the ablation edge under microscope. Measure and compare the melting maximum longitudinal diameter(L), maximum transverse diameter(D), horizontal cross-section area, volume In CT and general pathology; repeat above measures insteaded by 1 mm- slice CT scan.Results: Radiofrequency ablation in CT images: maximum longitudinal diameter L(4.23±0.35)cm; Maximum transverse diameter D(3.08±0.19)cm; Cross-sectional area S(10.27±1.24)cm2; Volume V(21.25±3.60)cm3.In pathological general L(4.19±0.47)cm; D(2.97±0.30)cm; S(9.80±1.68)cm2; V(19.64±4.94)cm3.Microwave ablation in CT image L(5.34±0.39)cm; D( 3.83±0.44) cm;S( 16.15±2.79) cm2;V( 41.96±12.02) cm3.In pathological general L(5.11±0.38)cm; D(3.39±0.56)cm;S(13.67±2.88)cm2; V(31.82±11.91)cm3.Conclusion:1 Pathological results about RF and MW ablation have a good correlation with CT manifestations, are slightly less than CT, but there is no statistical differences.2 The shape of RF and MW ablation area in CT manifestations and pathologic have a good consistency, CT can be used to evaluate curative effect of ablation, which melting damage in general pathology have corresponding performance on CT images.3 In CT performance, the reaction regions behave three different layers, which corresponding with necrosis, hemorrhage and edema under microscopic. For definiting boundary and local details, layer CT analysis is helpful. But it may overestimate the necrotic area range just making high-desity ground glass shadow boundary purely.4 The bleeding ablation nearby have an impact to the early melting curative effect.5 CT scan with local thin layer detail analysis can accurately evaluate effect of ablation. Part Three Injury and related complications research of the RF and microwave ablation to normal ventilation lung tissueObjective: To observe the RF and NW damage and the edge of the melting area necrotic tissue of on the normal ventilation pig tertiary bronchi and lung tissue,compare the various melting complications, provide experimental evidents for clinical treatment.Methods: Healthy pigs 6, two ablation regions on each side, put the needle point 0.5 cm away from tertiary bronchi, centered on melt tip, within 4 cm diameter can not contact pleura and mediastinal, ablation region is not overlap. Perform radiofrequency ablation(RFA) on the left lungs under CT guiding, and microwave ablation(MWA) on the right ons. Melting at the same time, 10-minute long.After the ablation, kill experimental animals by injecting excess does, get integral lungs out and fixed, get the melting stove tertiary bronchi and its surrounding tissues, melt stove solidification area and the organization of reaction area, observed under microscopic.Results: The experimental animal can tolerate RF and microwave ablation, no intraoperative death, restlessness, and subseguently reliefed after injecting additional drugs during melting process.All focal ablation appear different degree of bleeding, distribute along the lung segment distribution. Microwave can identify bleeding is a little slower than RF. RF ones has six cavities(50%). RF ablation sides: 2 lungs(33.33%) do not appear pneumothorax; 2(33.33%) ones do not appear pneumothorax in the first puncture, the second time little pneumothorax appear;1(16.67%) dose not apparent pneumothorax the first, suddenly pneumothorax appear the second time and develop to the medium, emergency extraction continuously by syringe, till the end of the experiment,1(16.67%) appears little pneumothorax during the first time of melting, no addes at the second time of puncturing.Microwave ablation side: 3 lungd(50%) did not appear pneumothorax;1(16.67%) does not appear obvious pneumothorax for the first time; econd time little pneumothorax; 2(33.33%) for the first time appear little pneumothorax, second no gas added.Rf damage is mild to tertiary bronchi, microwave damage is more serious.Within Rf and microwave necrotic area, complete bronchioles and small blood vessels are still visible.Conclusion:1 Both RF and microwave has no serious complications in the process of experiment, and they are relatively effective and safe way of micro-treatment method.2 The probability of pneumothorax and bleeding by radiofrequency ablation and mircrowave ablation has no statistical differences.3 Bleeding and pneumothorax are the most common complications for RF and WA ablations, that generaly no extra special treatments are needed.4 0.5cm away from the tertiary bronchi that ablation stitch put, RF damage is lighter, WA is more serious. Long-term effects remain to be further research. |
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