Predictors of the need for custom cannulas in patients with difficulties in tracheal cannula management

Abstract

Pediatric patients with a tracheostomy may develop scoliosis, altering the shape of the trachea. This change can make tracheal cannula management challenging, eventually requiring the use of adjustable length cannulas and custom cannulas. The aim of this study was to identify the factors predicting the requirement for custom cannulas. We compared two groups of cases that received adjustable-length cannulas: 12 cases in which the variable-length cannula alone was sufficient (adjustable length group), and three cases in which a custom cannula was necessary (custom group). CT of the trachea revealed significantly greater tracheal tortuosity and a significantly smaller tracheal cross-sectional area in the custom group. Although there was no significant difference in curvature, it was higher in the custom group. The formulation of indices that combine cross-sectional area with curvature, as well as cross-sectional area with tortuosity, indicated the necessity for a custom cannula when the cross-sectional area was below 85 mm², and either curvature was higher than 0.45 m⁻¹ or tortuosity was higher than 1.04.