Cryosurgery, as monotherapy or in combination with other therapeutic regimens, is an effective procedure to use for the treatment of keloids and hypertrophic scars.1 The inability of skin surface cryosurgery to freeze beyond 20 mm makes techniques for applying cryosurgery in depth attractive for treating old fibrotic and large keloids. We modified the method introduced by Weshahy2 and developed a device which consists of a small liquid nitrogen dewar that engages a sterile disposable 20-gauge needle connected by a flex-ible, long metallic cryoprobe stem (Figure 1A). The cryoprobe stem is attached to the needle with a Luer lock, and its shape is variable so that the dewar can stay upright during freezing. The shape of the needle can also be changed to form an angle, curve, or hook. The needle, which is introduced into the skin after a topical anesthetic is administered, runs through the deepest part of the lesion and appears at the surface on the opposite border. Liquid nitrogen is then sprayed through the needle and exits to the atmosphere. An ice cylinder is formed around the embedded part of the needle within the deeper tissue (Figure 1B). The distance of extension of freezing can be clinically estimated by the degree of extension of the whitish ice balls that are formed around the contact points of the needle to the skin surface. Compression of the lesions is accomplished by pulling up the visible parts of the needle.
Zouboulis CC, Rosenberger AD, Forster T, Beller G, Kratzsch M, Felsenberg D. Modification of a Device and Its Application for Intralesional Cryosurgery of Old Recalcitrant Keloids. Arch Dermatol. 2004;140(10):1293-1294. doi:10.1001/archderm.140.10.1293