X-Message-Number: 24536 From: "Basie" <> Subject: It is all about pressure Date: Thu, 19 Aug 2004 16:16:56 -0400 It is all about pressure. Even this document does not show what really happens. But it is not about the cutting or the "hamburger" effect. Basie See:http://www.2rui.com/html/cryopres.html <As the temperature drops to -15 degrees centigrade, ice crystals form within the cells and cause the cell membrane to explode> Cryosurgical Ablation of the Prostate Principles of the technique and the Grant/Riemenschneider experience, October 2001 - March 2003 More information on Cryosurgery and prostate cancer available here Definition of Cryotherapy - Invitro freezing and destruction of tissue that can be applied and controlled precisely to produce a predictable zone of tissue death that will destroy the "target lesion" (bad cells) as well as an appropriate margin of surrounding tissue (J Surg Oncology, 1966; 256-264). The third generation cryo-probe is a needle that has fantastic engineering built into it. The caliber of the cryo probe is the same as needles that are used to draw blood from a patient's arm when obtaining lab work. This cryo probe has the ability to produce very cold temperatures and results in the formation of "lethal ice". This probe also has the capacity to transmit heat through the probe to stop the growth of the ice ball. The mechanism by which these cold temperatures kill the target cells occurs in three ways. First, the extracellular ice formation occurs at -7 degrees centigrade. Second, ice crystals form between the cells and in so doing, dehydrates the space which draws water from the cells causing the cells to dehydrate. Three, the dehydration destroys or severely injures the biological mechanism of the cell that keeps it alive. As the temperature drops to -15 degrees centigrade, ice crystals form within the cells and cause the cell membrane to explode. As this process continues, the blood that flows through the vessels within these tissues coagulates and the blood supply to these tissues is cut off, eliminating adequate sources of oxygen and nutrition to the target cells. The history of cryosurgery tells us that the early cryo probes were very large and the cooling agent was liquid nitrogen. This agent is very effective resulting in very cold temperatures and hard freezes. These probes had no warming element and therefore, the freeze was very difficult to control. The second-generation cryo probes were smaller and used Argon gas as the cryogen, was more controllable than liquid nitrogen and includes a heating element that is based on the expansion of Helium gas being pumped through the probe at the right time. The third generation cryo probe uses Argon for freezing and Helium for heating. It is much smaller than the second generation probes, it is a 17-gage needle. This needle is so small it can be placed with pinpoint accuracy at the time of freeze and will result in the cell death cycle which occurs at the target tissue. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=24536