Lam CM, Shimi SM
Department of Surgery, University of Dundee, Dundee, Scotland
Semin Laparosc Surg. 1997 Jun;4(2):89-95. doi: 10.1053/SLAS00400089.
There has been increased recent interest in hepatic cryosurgery for primary and metastatic tumors in the liver. This has been realized through technological advances in intraoperative ultrasound monitoring and cryoprobe technology. Purpose-designed needle implantable cryoprobes have been developed to freeze deep-seated tumors in the hepatic parenchyma. However, the biophysical and thermal characteristics of these implantable cryoprobes have not been studied. This article discusses the biophysical and thermal characteristics of recently developed high-efficiency, implantable needle cryoprobes that can be used laparoscopically. The cryolesion was formed along the whole length of the cryoprobe implanted into hepatic tissue. It was cylindrical in shape and extended 8 mm beyond the tip of the cryoprobe after 20 minutes of freezing. During this period of freezing, the volume of the cryolesion increased in a near constant manner, but the diameter increased in a logarithmic fashion. In addition, single-cycle freezing produced a larger cryolesion than a dual freeze cycle interrupted by a 5-minute thaw. Further, increasing the length of cryoprobe implantation increased the volume of the cryolesion, although the diameter was smaller. The rate of cooling at the tip of the cryoprobe was also faster with partial implantation of the cryoprobe than with complete implantation. The cooling rate varied vertically along the length of the cryoprobe, as well as horizontally from the cryoprobe.
近期，肝脏原发性和转移性肿瘤的肝脏冷冻手术受到了越来越多的关注。这是通过术中超声监测和冷冻探针技术的技术进步实现的。专门设计的可植入式冷冻探针已被开发出来，用于冷冻肝实质内的深部肿瘤。然而，这些可植入式冷冻探针的生物物理和热特性尚未得到研究。本文讨论了最近开发的可用于腹腔镜手术的高效、可植入式针状冷冻探针的生物物理和热特性。冷冻损伤沿着植入肝组织的冷冻探针的全长形成。它呈圆柱形，冷冻20分钟后超出冷冻探针尖端8毫米。在冷冻期间，冷冻损伤的体积以近乎恒定的方式增加，但直径以对数方式增加。此外，单周期冷冻产生的冷冻损伤比中断5分钟解冻的双冷冻周期更大。此外，增加冷冻探针植入的长度会增加冷冻损伤的体积，尽管直径较小。冷冻探针部分植入时，其尖端的冷却速度也比完全植入时更快。冷却速度沿冷冻探针的长度垂直变化，并且从冷冻探针水平变化。
