Reduction of amputations of frostbitten limbs by treatment using microwave rewarming

Abstract

Drug treatment of limb frostbite injuries is complicated due to the poor delivery of medications to affected tissues. External rewarming of the frostbitten area is risky and does not always result in positive outcomes because the dilatation of superficial vessels with constricted deep vessels can lead to irreversible damage, necrosis, and amputation. One of the techniques to restore perfusion of deep vessels in an affected extremity is rewarming with low-power microwave radiation in a specially designed metal chamber. Below are findings following treatment of 14 volunteers with this technique in 2 Tomsk hospitals during winters of 2018–2021. It is demonstrated that timely, i.e. in the early reactive period, application of microwave radiation and appropriate supportive drug treatment results in positive amputation-free outcomes. The key requirement is prompt thermal insulation of the trauma and no prior exposure to external heat sources.

Microwave Therapy for Frostbite Management: A Case Series

“…As already mentioned in the introduction section, the effect of microwave warming in treating frostbites has shown positive results. Of note, the safety and effectiveness of microwave therapy for frostbites have been shown in a large series of patients [ 21 ].…”

“…Despite this, the microwave therapy used in this study differs and has advantages over the systems described in previous articles. In contrast to the microwave system used in the study by Dunaevskiy and colleagues [ 21 ] that is a closed metal chamber with a microwave generator capable of treating only the frosbitten extremities, Onda system is equipped with a handpiece that can be positioned in contact with the patient’s skin without causing damage (safety assured both by the presence of a cooling system and by the fact that the handpiece can be accessorised with a contact and temperature sensor) and capable of treating the entire affected limb. It is assumed that the hyperthermia, caused by treatment with Onda, led to an increase in hyperemia of blood vessels resulting in greater tissue oxygenation, not only in the treated area but also all over the interested limb up to the extremities affected by frostbites.…”

“…In the study of Dunaevskiy and colleagues [ 21 ] all volunteers are only male subjects. Furthermore, as women and children have less “volume” in their extremities, microwave power and procedure duration must be reduced.…”

“…Recent published researches [ 5 , 21 , 22 ] demonstrated an initiate deep warming of frostbitten extremities on exposure to low-power microwave radiation and the successful microwave treatment with a frequency of 2.45 GHz of cold injury of patient hands and feet that allowed amputation to be avoided.…”

Microwave Rewarming of Limb Frostbite Injuries (Simulation of Modes)

“…In 2019-2022, a total of 14 patients underwent treatment with this technique [34,35]. For the majority of patients, the technique indeed helped prevent amputation altogether or considerably lessen the scale of it.…”