Stem cells and bronchial stump healing.

OBJECTIVE: Bronchial stump dehiscence is still the most feared complication for the thoracic surgeon, with mortality rates ranging from 25% to 75%. This study reports the histologic effect of adult stem cells in the healing process of the bronchial stump after lung resection.

METHODS: A left pneumonectomy was performed in 36 Wistar rats. Half of them received previously labeled bone marrow-derived stem cells applied to the bronchial stump. In each group, 7 rats were sacrificed on day 7 and 11 rats were sacrificed on day 21. Macroscopic variables and histopathologic features were analyzed.

RESULTS: On days 7 and 21, there were fewer adhesions in the stem cell group (P = .042 and .031, respectively). Bronchial stump restitutio ad integrum on day 21 was found predominantly in rats from the stem cell group (P = .012). At that time, the same group showed significantly less inflammation in every layer of the stump (P < .050).

CONCLUSIONS: Bone marrow-derived stem cells administered topically on a bronchial stump are able to migrate, reach the bronchial wall, and participate in the healing process. This induces fewer adhesions, less inflammatory response, and better regeneration of the tissue.