Objective To compare the difference of preparing the acellular larynx scaffold between perfusion method and immersion method, and find better way to make acellular larynx scaffold for tissue engineering. Methods Twenty 6-month-old male New Zealand rabbits, weighing 2.0-2.5 kg, were divided into perfusion group (n=10) and immersion group (n=10) at random. All the larynxes were excised in a sterile fashion. The acellular larynx scaffold was obtained by perfusionmethod and immersion method respectively, and then comparative examinations were performed by the macroscopicview, histological view, scanning electron microscope (SEM), cartilage vital ity assay and toluidine blue staining. ResultsMacroscopic view showed that the larynxes perfused by sodium dodecyl sulphate (SDS) became transparent after 2 hoursof perfusion, but the larynxes immersed by SDS over 16 hours still appeared pink-white. Histology and SEM indicated thatcompared with immersion group, perfusion group showed better acellular effect, more ventages and collagen fibers wereretained, no intact cell or nuclei remained in acellular matrix and chondrocytes were still survival. The porosity was 85.39% ± 3.16% in perfusion group and 34.72% ± 4.51% in immersion group, showing significant difference (P lt; 0.01). The chondrocyte vital ity rate of perfusion group (86.93% ± 1.52%) was higher than that of immersion group (77.73% ± 1.66%), showing significant difference (P lt; 0.01). Toluidine blue staining showed that the chondrocyte heterochromaty was ber in perfusion group than that in immersion group. Conclusion Compared with immersion method, perfusion method is a better way to construct acellular larynx scaffold because it can achieve better acellular effect and retain chondrocyte vital ity at the greatest extent in the acellular larynx scaffold.
Objective To investigate the effectiveness of various materials in reconstruction of laryngotracheal framework and to analyze the advantages, disadvantage, and indication of each material. Methods The cl inical data were retrospectively analyzed, from 337 laryngotracheal stenosis patients undergoing laryngotracheal framework reconstruction with various materials between October 1986 and October 2006. There were 229 males and 108 females aged from 2 to 54 years (median, 23.5 years). According to Cotton’s grading criteria for laryngotracheal stenosis, there were 94 cases of grade II, 218 cases of grade III, and 25 cases of grade IV, and all accompanied by laryngotracheal framework defect of 1-5 cm. The costal cartilage autograft was performed in 157 cases, thyroid cartilage graft in 27 cases, nasal septal cartilage graft in 8 cases, sternohyoid myocutaneous rotary door flap graft in 104 cases, hyoid bone flap of sternocleidomastoideus graft in 7 cases, musculo-periosteum flap of sternocleidomastoideus with clavicular periosteum in 21 cases, hydroxyapatite artificial tracheal ring graft in 10 cases, and pedicle myocutaneous flap with “C” shape nickel-titanic alloy net graft in 3 cases. Silastic T-tube was used after reconstruction for 6-12 months. Results Infection occurred in 5 cases and the incisions healed by second intention, the others achieved healing of incision by first intention. Intratracheal granulation formation occurred in 23 cases and choke when taking food in 6 cases; they were all cured after symptomatic treatment. After operation, 4 cases failed to be followed up and 12 cases did not recover, including 6 cases of costal cartilage autograft, 1 case of hyoid bone flap of sternocleidomastoideus graft, and 5 cases of sternohyoid myocutaneous rotary door flap graft. A total of 321 patients were followed up for 1-10 years (mean, 3.5 years). The patients had no laryngotracheal restenosis with good swallowing function and respiratory function. Conclusion Different materials of laryngotracheal framework reconstruction have advantages and disadvantage respectively. The appropriate material should be selected according to the special details of pathological change, and the satisfactory curative effect may be obtained.