Axial shortening of the native trachea with graft necrosis was observed in our previous study in which long segments of sheep trachea were replaced with allogenic aorta. Unfortunately, a viable tracheal replacement graft has yet to be determined. The aim of this study was to test a bioabsorbable tracheal graft.
Eight male sheep underwent cervical tracheal replacement (5cm long) utilizing an (18 mm diameter) L-lactide andε-caprolactone tube graft (Gunze Ltd, Kyoto, Japan). A silicone stent (7cm) was inserted in the graft to prevent airway collapse. Routine bronchoscopy and CT scans were performed at 1 month and up to 9 months after engraftment.
No procedural deaths or postoperative complications occurred. Planned sacrifice occurred at 9 months (n=3), 6 months (n=2), 4 months (n=1), 3 months (n=1), and 2 months (n=1). CT imaging of the grafted area demonstrated axial contraction of grafted area up to 70% at 9 months after surgery. Airway collapse was observed at 6 hours, one week and two weeks after the stents were removed in the three sheep at 9 months. Complete epithelialization of the grafted area was confirmed in all sheep euthanized at 6 months and 9 months without signs of tracheal cartilage ring regeneration.
A bioabsorbable graft is a viable scaffold for long segment tracheal replacement. In parallel to our previous report, the mechanism of healing includes significant axial foreshortening of the native trachea but without graft-related necrosis or infectious complications.
Axial shortening of the native airway in conjunction with a bioabsorbable airway scaffold/graft may facillitate reconstruction of large or long tracheo-bronchial defects.
Hisashi Tsukada, No Financial Disclosure Information; No Product/Research Disclosure Information