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Backgrand: For patients with long segment of tracheal stenosis, resection and replacement is necessary. Tracheal reconstruction associated with complications such as stenosis, insufficiency of blood supply and surgical complication. Methods: In this study, we prepared collagen-chitosan scaffold and sheep's decellularized trachea plus culture medium with nanocup contain growth factors for chondrocyte and fibroblast-epithelial cell culture in rotary bioreactor. After attachment of cells, engineered trachea put into the omentum. Peritoneal stem cell interact with the epithelial and chondrocytes with attendance of growth factors released from nanocup. The bioengineered trachea with omental pedicle transposed from behind the sternum and transplanted in the position of resected trachea. In third experiment, we introduce the in situ tracheal repair technique with injectable matrix for reconstruction of long-segmental stenosis of trachea in a 29-year-old woman. Results: Severe tortuosity in the first experiment and mild stenosis was seen in the second experiment. In third experiment, normal shape in tracheal diameter was seen at injection sites. The interior portion of the trachea at virtual computed tomography (CT) scan and bronchoscopy were similarity to normal after four month fallowing up of injection. Conclusions: Severe tortuosity, mild stenosis in whole length of trachea in this study and disadvantage of trachea transplantation include open surgery, fatal consequences of anastomosis leakage, and rupture besides large mediastinal vessels; hence, we decided to introduce the novel in situ tracheal repair technique. Injectable bioresorbable scaffolds may be used as a temporary scaffolding for transplanted cells and thereby allow the cells to secrete extracellular matrix of their own to enable, in the long term, a complete and natural tissue replacement.

Background and Aims The efficacy of flexible cryoprobe in providing high-quality tissue specimens through bronchoscopy for making a diagnosis remains debatable. In this study, we have compared the diagnostic yield of cryoprobe with conventional sampling by forceps. Methods Forty-one patients scheduled to undergo transbronchial lung biopsy (TBLB) in a pulmonary hospital in Tehran, Iran. Each patient underwent conventional TBLB and flexible cryoprobe TBLB (FCLB) sequentially. Specimen adequacy was defined by the presence of at least 50 alveolar spaces or a positive diagnostic yield. Adequacy of specimens, number and percentage of alveolar spaces without artifact, type of artifact, presence of bronchiolar structures and the diagnosis made based on the results of the two methods separately were compared. Results The mean values of tissue section area obtained by forceps and cryoprobe were 6 mm2 [standard deviation (SD) ± 6.7] and 22 mm2 (SD ± 19.1), respectively (P 75% artifact-free lung parenchyma was significantly higher in FCLB method. Conclusion FCLB method provides larger tissue samples with better quality compared with TBLB. Higher-quality specimens are associated with less artifact and higher diagnostic yield. Multisite randomized trials are required to improve our knowledge about the benefits and indications of TBLB with cryoprobe.