Читать книгу Complications in Equine Surgery - Группа авторов - Страница 171

The goal of cryosurgery is to destroy unwanted cells by freezing, similar to the tissue injury that occurs in frostbite. As the procedure does not involve a real “surgery,” a more correct but less commonly used term would be cryoablation.

In equine medicine, cryosurgery was widespread in the 1980s and the technique was not only used for the treatment of tumors but also for cryoneurectomy and pain alleviation in a variety of orthopaedic diseases such as bone spavin, proximal suspensory desmitis and splint bone fractures [1, 2].

Nowadays, cryosurgery in horses is almost exclusively used for oncological applications, more specifically for the treatment of equine sarcoids and squamous cell carcinomas [3–7]. Non‐oncological applications include the destruction of the hair follicle in distichiasis [8] and the management of patent urachus [9].

Cryosurgery can either be used as the sole treatment for tumors, or as an adjunctive to surgical resection [4, 5]. Tissue injury arises from direct damage to the cell wall by intracellular ice‐crystal formation during fast freezing followed by recrystallization during the slow thawing phase [10], from microcirculation failure after the thawing phase, [11] and from post‐thaw cell stress resulting in apoptosis [12]. Maximal tissue destruction with freezing is obtained when 2 or 3 freeze–thaw cycles are performed [10].

The final result is coagulation necrosis which is characterized by the formation of a necrotic eschar that gradually detaches from the underlying granulation tissue starting from 7–10 days after cryosurgery. Complete sloughing takes approximately 2–4 weeks, but can also last up to 8 weeks [13, 14]. The resulting wound heals by second intention. The final skin scar is often depigmented and partially hairless due to destruction of hair follicles and the highly cold‐sensitive melanocytes [4, 15, 16].

The number of complications associated with cryosurgery is rather limited as long as good cryosurgical equipment is available, the technique is applied correctly, and an appropriate selection is made of lesions to which cryosurgery can be applied [15] (Table 11.1).