Study Of Safety And Co-efficiency Of The Transbronchial Ablative Techniques

ObjectiveIn this thesis, in vivo study of safety and co-efficiency of the transbronchialablative techniques. The usual transbronchial ablative techniques include: YAGlaser, electrocautery, argon plasma coagulation (APC), and CO2cryotherapy. Byanalyzing the experimental data and clinical observations of each ablativetechniques, we study the variable tissue effects of different techniques, to look foran optimal interventional management of luminal bronchus diseases, and evaluatethe safety and the equivalent point.Materials and MethodsPart I: To study the tissue effets after the four ablative techniques performed ontrachea wall. Bronchoscopic appearance of the treated area was documentedphotographically, and pathologic changes of the bronchial wall were observed.Part II: Obersver the recover of trachea wall after damaged by ablativetechniques.ResultsIn the first part: After each ablative techniques peformed on the mucosa oftracheae, the bronchoscopic appearance of the lesion include: whitening of themucosa with a small, well-defined lesion; crater-shaped lesions with charring andtissue defects. Examination of histologic changes showed local necrosis and amotioof the mucosa lining epithelium, local submucosa coagulative necrosis or tissuedefects. There is a good correlation between the visibility of mucosal damage duringtreatment session and the ultimate histologic changes. Even under the same power,tissue damage was deeper if the action time increased. The damage by APC was themost superficial, laser and electrocautery caused the worst damage, cryotherapy wasmore safety. The study also found that effects of electrocautery at40W×1second,laser at20W×1seconds, APC at40W×5seconds and cryotherapy at100×120seconds were the equivalent point conditions. The appearance included mucosa absence, partial submucosa absence, and collagen fiber coagulation in treatmentareas. At the same power and action time, we obsvered the cartilage layer wasstructural integrity, not perforation phenomenon. The dose of each ablativetechnique were safety.In the second part: The recover process of the damage trachea wall could beroughly divided into four periods: the acute injury stage; inflammatory reactionperiod; reparative phase; healing phase. The restoration approach of trachea wallmainly was fibrous tissue hyperplasia. The entire process needs about three weeks.ConclusionEach ablative technique has its own characteristic. It is very important to choosethe suitable method according to the therapy requirement, also make sure choose theappropriate power and action time.