Inflation Pressures for Ex Vivo Lung Biopsies After Application of Graduated Compression Staples.

OBJECTIVE: To compare 2 graduated compression staples (Tri-Staple™, Covidien, Norwalk, CT) and standard staples (Endo GIA™, Covidien) for lung biopsy in dogs.

STUDY DESIGN: Ex vivo experimental study, randomized, unblocked.

ANIMALS: Lung lobes (n = 18) from 4 canine cadavers.

METHODS: Eighteen lung lobes were harvested from 4 dogs immediately after euthanasia and randomized to 1 of 3 staples (n = 6 per stapler type). Each lung lobe was intubated and maintained inflated at 10 cmH2O. A biopsy of the periphery of each lung lobe was taken approximately 3 cm from the edge with a stapling device; the Tri-Staple™ medium/thick (TST), Tri-Staple™ vascular/medium (TSV), and Endo GIA™ 45-2.5 (EG). Each lobe was inflated to a maximum of 45 cmH2O of water to determine the pressure at which air leakage occurred (leak pressure).

RESULTS: The mean (95% confidence interval) leak pressure was 38.0 cmH2O (33.1-42.9) for EG, 29.2 (24.3-34.0) for TSV, and 26.0 (21.1-30.9) for TST. The mean leak pressure was significantly higher for EG than TSV (P = .016) and for EG than TST (P = .002), but was not different between TSV and TST (P = .344). One TSV leaked at 20 cmH2O and 1 TST leaked at 17 cmH2O. The surface area of the biopsy samples was not significantly different for staple types (P = .183).

CONCLUSION: Both TST and TSV leaked at significantly lower airway pressures than EG and may not be suitable for canine lung biopsy as some specimens leaked at pressures of 20 cmH2O or less.