Experimental study of the effects of different stapling devices in healing of the mechanically sutured bronchial stump

The invention of the mechanical suture of the bronchial stump resulted in the significant decrease of the incidence of bronchial fistulas. Bronchial fistula constitutes the most dangerous complication of the pulmonary resection. In connection with some negative opinions in world literature regarding the safety of applying some types of mechanical suture, the multi-factor analysis of efficacy of bronchial stump closure following the total pneumonectomy by two different types of stapling devices was performed.

The experimental study was performed on 22 sheep. Each sheep underwent left pneumonectomy. In group I the bronchus was closed by the hinged-jaw stapling device (TA-Premium, Auto-Suture). In group II the bronchus was closed by the stapling device of parallel pattern (RLV 30 Ethicon). The macroscopic parameters (i.e. linear structure of staples, degree of staples closure, the symmetry of staples closure in the medial and lateral part of bronchial stump) as well as microscopic parameters (i.e. degree of inflammatory reaction, degree disorder in collagen fibers system, degree of disorders in cartilaginous system, degree of vascular proliferation and nervous regeneration) were evaluated.

In three cases of group I the serious abnormalities in staples closure in the medial part of the bronchial stump were revealed. Abnormalities were found also in microscopic evaluation of the specimens. In the whole group the inflammatory reaction predominated in the medial part of bronchial stump near the hinge of the cartridge (P value <0.05). The disorder in the collagen fibers system as well as in the stratified structure of muscular fibers and cartilaginous system was proved. On the other hand, in group II all staples were properly closed in adequate linear structure, without any symmetry in both medial and lateral end of the bronchial stump. The microscopic findings were only the subtle inflammatory process and a slight disarrangement in muscular, collagen and cartilaginous systems.

The listed abnormalities of mechanical, hinged-jaw suture of bronchial stump seem to be due to the inaccurate placement of staples, their incomplete closure, and excessive damage to the sutured tissues. We conclude that the application of the hinged-jaw mechanical suture of the bronchial stump might result in higher incidence of bronchial fistula after pneumonectomy.