Time necessary for neovascularization of a tracheal segment by the sternohyoid muscle.

Introduction: The reimplantation of a complete tracheal segment (CTS) as an autograft or homograft often results in total or partial necrosis of the CTS. However, previous experiments suggested that when the CTS is first vascularized by the sternohyoid muscle (SM) 21 days before the reimplantation, the CTS can be reimplanted without ischemia or stenosis. However, it is not clear if the CTS requires 21 days to attain full revascularization.

Goal: This study aims to ascertain the minimum time necessary for revascularization of the 6 rings CTS by the SM allowing reimplantation free of ischemia.

Methods: Fifteen mongrel dogs, divided into 3 groups were submitted to 2 sequential surgical procedures. In the first procedure, a SM flap was used to envelop 6 rings CTS in all dogs. After periods of 21 days (group 1, n = 5), 14 days (group 2, n = 5) and 7 days (group 3, n = 5), the compound flaps (CTS and SM) were neovascularized. Each CTS was transected and mobilized from the trachea and then replaced again in its original site, as an autoflap.

Results: After a period of at least 60 days, none of dogs presented any respiratory alteration. Macroscopic and microscopic analyses demonstrated adequate viability and no stenosis.

Conclusion: Our findings suggest that it is possible to neovascularize the CTS using a SM flap within a period as short as 1 week.