[The effects of bacterial infection in bronchial stump healing and the usefulness of the mechanical stapling device].

It is an important problem to associate bacterial infection in the process of bronchial stump healing. Wound healing processes in two types of bronchial stump closure methods, hand suturing with absorbable threads and mechanical stapling with stainless steel staples, were compared in mongrel dogs (154 dogs) which underwent right upper lobe reactions with and without infections. Half of the animals were infected with 10(9) CFU/dog of Pseudomonas aeruginosa E7 organisms. In order to understand the influence of bacterial infection on bronchial stump healing and also to evaluate the usefulness of the mechanical stapling device, we studied the number of viable bacteria, the activities of collagenase types I, II, III and IV, the amount of hydroxyproline and the histopathological finding in the bronchial stump tissue and the maximum leakage pressure. The number of viable bacteria decreased daily, but more than 10(3) CFU/g were detected even on the 21st day in infected dogs. There were no organisms detected in the stump tissues of uninfected dogs. The maximum leakage pressure levels by the 14th day after operation in the infected group were lower than in the uninfected group regardless of closure method. In the infected group of mechanical stapling the maximum leakage pressure increased daily, and on the 21st day became almost equal to that of uninfected group of mechanical stapling. The activity levels of collagenase type I in the infected group of both methods were at a maximum on the 5th day. On the same day the amount of hydroxyproline was at a minimum, and maintained a low level until the 14th day.(ABSTRACT TRUNCATED AT 250 WORDS)