The threshold for air leak: stapled versus sutured human bronchi, an experimental study

Background: Little is known about the integrity of staple-closure of the br onchus and its tolerance to normal mechanical stresses (cough, sneezing, et c.) in the immediate early post-operative period. There are few studies whi ch tested the mechanical strength of stapled bronchial closure compared wit h manually closed bronchi using the threshold for fluid leak across the bro nchial suture line which differs from air. Material and methods: Intact cad averic tracheobronchial tree (n = 40) were selected, age range from 55 to 7 0, of which 60% were males. They were divided into two groups: group A, 20 left bronchi were closed with RLV 30 Ethicon(R) 4.8 mm bronchial stapler; g roup B, 20 were closed with 4 0 Prolene(R) simple interrupted sutures. All specimens were intubated with endotracheal tube and submerged under water b efore testing the immediate air leak with the standard 40 mm Hg inflation p ressure. Inflation pressure was increased until air leak was detected. The stapled closures were resected and subjected to radiological examination. R esults: No air leak was detected in any bronchus at 40 mmHg regardless of t he closure technique. The median leakage pressure was significantly higher in the hand sutured bronchi compared to the stapled group (200 vs. 105 mmHg , respectively) and 50% (n = 10) leaked from multiple sites in the stapled group compared with leakage from one site only in group B, this difference was statistically significant P < 0.001. The radiological appearance of the staples maintained the B configuration, recommended by the manufacturer as a sign of sound application. Conclusion: Hand sutured bronchi tolerated hi gher inflation pressure compared with the stapled ones before leaking air. Air leak at high pressure occurs in the presence of intact staples. (C) 199 9 Elsevier Science B.V. All rights reserved.