Differential scanning calorimetric examination of the tracheal cartilage after primary reconstruction with differential suturing techniques

Objective Long segmental tracheal defects often lead to life threatening clinical conditions. Treatment of these lesions still represents an unsolved surgical challenge. The aim of the study was to test the effect of continuous and simple interrupted suturing in the replacement of long segment tracheal defects using polytetrafluoroethylene (PTFE) vascular prosthesis in a rabbit model. Methods 2 cm long segment of the cervical trachea was resected in 20 New Zealand rabbits. The trachea was replaced with reinforced polytetrafluoroethylene vascular graft. The anastomoses were performed telescopically using continuous (group I, n = 10) or simple interrupted sutures (group II, n = 10). Laser Doppler measurements were taken before the resection and following the anastomoses. Length of survivals were noted, the patency and microscopical pattern of the anastomoses were evaluated. Calorimetric examinations were performed to detect possible structural changes in the tracheal cartilage. Results Following the resection local microcirculation decreased by 9 ± 4%. The anastomoses caused a significant decrease of 29% in group I (p = 0.02) and 13% in group II. The mean survival was 58 ± 17 and 135 ± 25 days, respectively. Calorimetric results showed no change after the resection, but significant shift in melting temperature and calorimetric enthalpy proved the presence of structural changes of the cartilage in group II. Conclusions We saw significant lowering of microcirculation following continuous sutures, while simple interrupted stitches produced only moderate decrease. We found that interrupted suture technique is superior to the continuous technique causing only moderate damage to the tracheal anastomosis.