Retrieval of various aspirated foreign bodies by flexible cryoprobe: in vitro feasibility study

Retrieval of aspirated foreign bodies (FB) by flexible bronchoscopy is challenging. Many types of ancillary equipment, including forceps, grasping claws, snares, balloon-tipped catheters and magnets, have been developed to allow FB extraction using flexible bronchoscopes. The ability to remove a FB by flexible cryoprobe (cryoextraction) depends on the cryoadhesive properties of the retrieved object, which in turn depends on its physical properties.

Our aim was to explore ex vivo on a lung model the cryoadhesive properties of various commonly aspirated objects.

The tested FB compromised of nine organic and nine inorganic commonly aspirated objects. An attempt was made to retrieve each object from a lung model by flexible cryoprobe at 5 and 10 s application time and following rinsing by normal saline.

Whereas most organic objects (for example chicken and fish bones) were retrievable by cryoprobe, most inorganic objects (for example safety pin and paper clip) are not retrievable by cryoadhesion. On the other hand, several inorganic objects (for example dental cup) despite their low water content were cryoadhesive.

FB retrieval by cryoprobe is feasible for many organic and inorganic aspirated objects. However, the cryoadhesive properties of most inorganic FB and several organic objects is unpredictable, hence, if the nature of the FB is known, an identical object should be used to practice the technique of retrieval in vitro, prior to attempting to perform the procedure in the patient.