Zouboulis V A, Zouboulis C C
Faculty of Medicine, Universitaetsklinikum Hamburg-Eppendorf (UKE), Hamburg, Germany.
Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany.
J Eur Acad Dermatol Venereol. 2020 Aug;34(8):1851-1854. doi: 10.1111/jdv.16267. Epub 2020 Mar 22.
Intralesional cryosurgery is effective in the treatment of keloids; however, clinical studies have presented diversified results.
A novel, reproducible model for biophysical studies on intralesional cryosurgery of keloids is presented.
Triplicate studies with a cryosurgical needle on 37°C-heated potatoes, which exhibit identical specific heat and similar heat conductivity with human skin, were performed.
No complete potato freezing resulted through a cryosurgical needle. The limited tissue damage achieved had a double concave form. The needle induced lower temperature and stronger tissue damage at the distal exit than the proximal entrance site. The concave form of tissue damage flattened with time at the area under the needle. Needle freezing with puncture distances of 0.5, 1.0 and 1.5 cm from the potato surface only revealed freezing temperatures within the 0.5 cm range. At any needle depth, tissue damage was detected at only an area to about 1 cm under the needle.
Clinical extrapolation of these experimental findings indicates a proper needle positioning towards the keloid basis, shows keloid volume freezing limitations by a single needle and corroborates the observations of minor epidermal and deep dermal damage induced by intralesional cryosurgery.
病灶内冷冻手术在瘢痕疙瘩治疗中有效；然而，临床研究结果呈现出多样化。
提出一种用于瘢痕疙瘩病灶内冷冻手术生物物理研究的新型、可重复模型。
使用冷冻手术针在37°C加热的土豆上进行了三次重复研究，土豆的比热与人皮肤相同，热导率与人皮肤相似。
冷冻手术针未能使土豆完全冻结。所造成的有限组织损伤呈双凹形。针在远端出口处导致的温度低于近端入口处，且组织损伤更强。针下方区域的组织损伤凹形随时间变平。针从距土豆表面0.5、1.0和1.5厘米的穿刺距离进行冷冻，仅在0.5厘米范围内显示出冷冻温度。在任何针深度下，仅在针下方约1厘米的区域检测到组织损伤。
这些实验结果的临床推断表明，应将针正确定位在瘢痕疙瘩基底处，显示出单针冷冻瘢痕疙瘩体积的局限性，并证实了病灶内冷冻手术引起轻微表皮和深层真皮损伤的观察结果。
