Preventing Laryngeal Anterior Commissure Adhesion After Operation: A Study In Canines

Objective To explore the better operational methods by the laser surgery to treat diseases involving the laryngeal anterior commissure. It can excise the diseases as well as avoid anterior commissure adhesion, laryngostenosis and dyspnea after operations.Methods Twelve dogs were divided into 4 groups at random .There are three dogs in one group. A: excising experimental dog's anterior cimmissure by twice operations, the interval time is two weeks; B: excising experimental dog's anterior cimmissure in one time, at the same time suturing the silica gel sheet on the anterior commissure; C: excising experimenal dog's anterior cimmissure in one time and then applying MMC on the wound of the anterior commissure; D: excising experimental dog's anterior cimmissure in one time, without any treatment. After 4 weeks, we observed the raw surface of each group, measured the vocal cord length and glottis area before and after operations.Results All of the dog's surgery were completed successfully by laser. 4 weeks later, we observed the raw surface: Group A: the neonatal membrane covered the wound, inflammatory reaction lightly, we could not see obvious adhesion in the anterior commissure. Group B: the membrane covered the wound, appearing the dark chronic inflammation, we could see the adhesion in the anterior commissure lightly. Group C: the membrane covered the wound, edematization, we could see the moderate adhesion in the anterior commissure. Group D: edematization, we could see the adhesion in the anterior commissure obviously. 4 groups are all had hoarsenesses, slightly in group A, secondly in B and C , the worst in D. The analysis of vocal cord length of 4 groups, we used matched-pairs t-test, A,B,C groups'P>0.05, the vocal cord length didn't become shorter than before obviously. Group D's P<0.05, that meant the vocal cord length became shorter obviously. Between each group , we use reiterature - measurement analysis of variance(P<0.05), the change of vocal cord length had disparity in different groups. The comparison in two groups suggested that group A is the best. B and C are inferior ,but no disparity between them. The analysis of glottis area of 4 groups, As the same method above, A,B groups'P>0.05 ,the glottis area didn't shrink than before obviously. C and D groups'P<0.05, that meant having statistical significance and glottis area shrinked obviously. Between each group , we use reiterature - measurement analysis of variance ( P>0.05),we can not think that the changes of four groups have disparity. we observed the pathological section by HE staining ,Group A: tissu hydropsia, slit-shaped blood vessel in the submucosum ,little neutrophil and lymphocyte; Group B and Group C: hyaline degeneration obviously in the stroma,we can see neutrophil and lymphocyte and newly born blood capillary; Group D: we can see large of neutrophil and lymphocyte and a lot of hyperplastic Small vessels. we observed the pathological section by VG staining, injuried tissues have considerablely collagen fiber, Group A has content least, Group B has content moderately, Group C has content more and Group D has content maximum.Conclusions Excising the experimental dog's anterior cimmissure by laser, compared the 4 different operation methods, Group A is the best method. B and C are inferior. Group D is the worst method.The results are valuable in clinic when we perform operations by laser to treat the disease involving the anterior commissure.