Dynamic Obstruction due to Unfurling of Spirals in a Flexometallic Tube

Flexometallic tubes are kink-resistant and extensively used in neurosurgeries. The manufacturers of flexometallic tubes recommend single usage. In low-income countries, due to the cost restraints, flexometallic tubes are commonly reused after ethylene oxide sterilization. With this technique, flexometallic tubes are effectively sterilized, but the physical integrity of the endotracheal tube cuffs may be compromised.¹  Tube kinking²  and intraluminal blebs due to dissection³  are observed with the reused flexometallic tubes. These obstructions lead to difficulty in ventilation and inability to pass a suction catheter freely. Flexometallic tubes should be thoroughly checked for external deformity, cuff integrity, and tube patency for safe reuse.

Despite thorough assessment of reused flexometallic tubes, the partial unfurling of nylon spirals with distal herniation into the tube (panels A and B) may still happen intraoperatively, leading to dynamic obstruction resulting in variable resistance during suction catheter negotiation (see Supplemental Digital Content 1, video S1, https://links.lww.com/ALN/C848). Along with the heavy weight of the circuit, the varied positions of head and neck result in additional rotational bending of flexometallic tubes, contributing to partial unfurling, which may not cause complete airway obstruction but can lead to difficult ventilation requiring airway change. The simple technique of passing a suction catheter through flexometallic tubes can help in identifying such partial tube obstruction. Reinforced tracheostomy tubes are also frequently reused after a thorough cleaning and visual inspection.

Adhering to the manufacturer’s recommendation regarding reuse is the best way to prevent these complications. However, when clinically necessary and under the right circumstances only, flexometallic tubes should be reused after a thorough assessment.